Research ArticleAssociation of Nuclear Factor-Erythroid 2-Related Factor 2Thioredoxin Interacting Protein and Heme Oxygenase-1 GenePolymorphisms with Diabetes and Obesity in Mexican Patients
1Department of Biology National Autonomous University of Mexico (UNAM) 04510 Mexico City DF Mexico2Economy Department Autonomous Metropolitan University-Iztapalapa 09340 Mexico City DF Mexico3Research Department Regional Hospital ldquoLic Adolfo Lopez Mateosrdquo ISSSTE 01030 Mexico City DF Mexico4Molecular Biology Department National Institute of Cardiology ldquoIgnacio Chavezrdquo 14080 Mexico City DF Mexico5Department of Immunology National Institute of Respiratory Diseases ldquoIsmael Cosıo Villegasrdquo 14080 Mexico City DF Mexico6Molecular Genetics Laboratory National School of Anthropology and History 14030 Mexico City DF Mexico
Correspondence should be addressed to Jose Pedraza-Chaverri pedrazaunammx
Received 4 January 2016 Revised 29 March 2016 Accepted 5 April 2016
Academic Editor Silvana Hrelia
Copyright copy 2016 Angelica Saraı Jimenez-Osorio et al This is an open access article distributed under the Creative CommonsAttribution License which permits unrestricted use distribution and reproduction in any medium provided the original work isproperly cited
The nuclear factor-erythroid 2- (NF-E2-) related factor 2 (Nrf2) is abated and its ability to reduce oxidative stress is impaired intype 2 diabetes and obesityThus the aim of this study was to explore if polymorphisms in Nrf2 and target genes are associated withdiabetes and obesity in Mexican mestizo subjects The rs1800566 of NAD(P)Hquinone oxidoreductase 1 (NQO1) gene rs7211 ofthioredoxin interacting protein (TXNIP) gene rs2071749 of heme oxygenase-1 (HMOX1) gene and the rs6721961 and the rs2364723from Nrf2 gene were genotyped in 627 diabetic subjects and 1020 controls The results showed that the rs7211 polymorphism is aprotective factor against obesity in nondiabetic subjects (CC + CT versus TT OR = 040 119875 = 0005) and in women (CC versusCT + TT OR = 07 119875 = 0016) TT carriers had lower high-density lipoprotein cholesterol levels and lower body mass index Thers2071749 was positively associated with obesity (AA versus AG + GG OR = 125 119875 = 0026) Finally the rs6721961 was negativelyassociated with diabetes in men (CC versus CA + AA OR = 062 119875 = 0003) AA carriers showed lower glucose concentrationsNo association was found for rs1800566 and rs2364723 polymorphisms In conclusion the presence of Nrf2 and related genespolymorphisms are associated with diabetes and obesity in Mexican patients
1 Introduction
The International Diabetes Federation has reported that thereare 382 million people living with diabetes worldwide [1]Type 2 diabetes (T2DM) is a public health problem in devel-oping countries with a direct impact in the economic andsocial sectors Being overweight and obesity are risk factorsto develop T2DM and could explain the dramatic increasein the incidence and prevalence of T2DM [2 3] Both
obesity and T2DM feature insulin resistance and atherogeniclipid profiles such as increased cholesterol and triglyceridesand decreased high-density lipoprotein cholesterol (HDL-C) It is widely accepted that oxidative stress is a commonmechanism in the development and progression of thesepathologies with an increased free radical production andreduced antioxidant capacity [4 5]
The master antioxidant regulator the nuclear factor-erythroid 2- (NF-E2-) related factor 2 (Nrf2) is a member
Hindawi Publishing CorporationOxidative Medicine and Cellular LongevityVolume 2016 Article ID 7367641 8 pageshttpdxdoiorg10115520167367641
2 Oxidative Medicine and Cellular Longevity
of the caprsquonrsquocollar family of basic leucine zipper transcrip-tion factors that regulates the expression of many antiox-idant genes including NAD(P)Hquinone oxidoreductase 1(NQO1) and heme oxygenase-1 (HMOX1) to avoid oxidativedamage [6] Also it has been demonstrated that Nrf2 activityis abated in diabetes and factors like age body weight andblood glucose could modify its activity [7ndash9] but geneticfactors have been poorly studied Many single nucleotidepolymorphisms (SNPs) have been identified in the Nrf2 gene[10] In particular the rs6721961 (C-617C) polymorphismhas been associated with oxidative stress and risk of newlydiagnosed T2DM [7] and increased blood pressure [11]The rs2364723 (C107G) polymorphism was associated withreduced risk of cardiovascular mortality [12] The NQO1gene polymorphism rs1800566 (C609T) is characterized bythe replacement of proline by serine at position number187 of the functional protein which causes destabilizationand inactivation of the enzyme [13 14] The rs1800566polymorphism has been associated with lower levels of bloodcoagulation factors [15] higher risk of coronary artery diseasein T2DM patients [16 17] and increased triglycerides levelsand decreased HDL-C levels in individuals with metabolicsyndrome [18] Polymorphisms in the promoter region ofthe HMOX1 gene such as rs2071746 (T-413A) and (GT)
119899
microsatellite have been associated with various humandiseases [19] however the rs2071749 polymorphism (AG)is not associated with hypertension andor blood pressurein hypertensive patients [20] It has been reported that theendogenous inhibitor of the thioredoxin (TXN) system thethioredoxin interacting protein (TXNIP) can be suppressedby Nrf2 [21 22] The rs7211 polymorphism in TXNIP wasassociated with inhibition of TNX glucose homeostasisdiabetes and hypertension [23] Individuals carrying the Tallele of the rs7211 polymorphism in the TXNIP gene showedhigher plasma triglycerides levels [24]
However despite the recent efforts to understand theassociation of antioxidant gene polymorphism with T2DMthe number of studies is still very limited in Mexican popu-lationThus the aim of this study was to investigate potentialassociations between Nrf2 (rs6721961 and rs2364723) NQO1(rs1800566) HMOX1 (rs2071749) and TXNIP (rs7211) poly-morphisms in a T2DM population
2 Materials and Methods
21 Study Design and Subjects A case control study wasperformed which included 1647 Mexican mestizo subjectsThis study was approved by the Ethics Committee on HumanStudies from the Committee on Research Ethics and Safetyof the Hospital Regional ldquoLic Adolfo Lopez Mateosrdquo withregistration number 2542013 and conducted in accordancewith the Declaration of Helsinki Written informed consentwas obtained from all subjects who were recruited in FamilyMedical Clinics of the Instituto de Seguridad y ServiciosSociales de los Trabajadores del Estado (ISSSTE) in MexicoCity
A standard questionnaire was applied to obtain demo-graphic information family and personal health history(diabetes andor further diseases) and information about
physical activity alcohol consumption smoking and drugsconsumption Their medical history data weight (kg) andheight (m) were obtained The body mass index (BMI)was estimated by dividing weight by the square of heightCriteria for inclusionexclusion of participants were as fol-lows the study included men and women aged 35 andolder nonpregnant and nonlactating women and subjectswithout excessive alcohol consumption The criteria forclassification and diagnosis of diabetes were according tothe standards in medical care on diabetes from AmericanDiabetes Association (ADA) Subjects of the control group(119899 = 1020) had fasting glucose lt55mmolL and glycatedhemoglobin (HbA1c) lt57 Subjects with T2DM (119899 = 627)had plasma glucose gt70mmolL and HbA1c gt65 Subjectswithmental health problems (senile dementia andAlzheimerand Parkinsonrsquos disease) and cancer were also excluded Therecruitment period was from May 2012 to October 2014 Atotal of 1627 individuals were recruited that self-reportedMexican mestizo ancestry (three generations) To each indi-vidual the information was given about the protocol andthose who decided to enter gave written informed consentto participate Anthropometric data (waist circumferenceheight and weight) and arterial pressure measurements wereobtained before blood collection
22 Blood Collection and Biochemical Analyses Whole bloodsamples (20mL) were collected from patients and controls(with fasting of 8ndash12 h) in order to determine the levels ofglucose triglycerides total cholesterol HDL-C low-densitylipoprotein cholesterol (LDL-C) and creatinine in serumusing an automatized analyzer (Miura 200 ISE RomeItaly) Moreover total blood with ethylenediaminetetraacetic(EDTA) acid as anticoagulant was used to obtain genomicDNA
23 Genotyping Genomic DNA from whole blood con-taining EDTA was isolated by standard techniques [25]The rs2364723 (Nrf2) rs1800566 (NQO1) rs7211 (TXNIP)and rs2071749 (HMOX1) SNPs were genotyped using pre-designed 51015840 exonuclease TaqMan genotyping assays on a 7500series Real-Time PCR system according to manufacturerrsquosinstructions (Applied Biosystems Foster City CA USA)Thers6721961 (Nrf2) TaqMan probe was designed according tomanufacturerrsquos directions
24 Short Tandem Repeats (STRs) Genotyping and AdmixtureEstimations Fifteen autosomal STRmarkers (CSF1PO FGATHO1 TPOX VWA D3S11358 D5S818 D7S820 D8S1179D13S317 D16S539 D18S51 D21S11 D19S433 and D2S1338)along with amelogenin were genotyped in 200 controls and200 cases using the AmpFlSTR Identifiler Kit (AppliedBiosystems Foster City CA USA) as previously described[26]
We performed admixture estimations using the STRrsquosallele distribution by a model-based clustering method withthe Structure software v 234 assuming 119896 = 3 populationsand 1 times 104 dememorisation steps The estimations ofAmerindian European andAfrican components in ourMex-ican studied groups were performed using the distribution of
Oxidative Medicine and Cellular Longevity 3
STRs alleles in different populations including Spaniards [27]Fang Africans [28] and a Native American pool of Huastecos[29] and Tepehuas [30] from the central region of Mexicowho were considered as parental populations
25 Statistical Analyses Continuous variables were analyzedusing a 119905-test and were presented as mean plusmn standarddeviation (SD) For categorical variables a Chi-square testor Fischer exact test was applied and data was presented aspercentage
The Hardy Weinberg equilibrium was calculated in con-trols using StatCalc software (Epi Info 2005 v332 Centersof Disease Control and Prevention Atlanta GA USA)Multivariable linear regression models were carried out foradjustment of glucose for potential confounders like agegender BMI and tobacco In order to assess the genetic riskfactor for diabetes and obesity logistic regression analyseswere applied to estimate the OR for each polymorphismBecause the associations between the SNPs and the outcomeshave been previously reported it is unlikely to detect effectsdue to statistical fluctuations only Therefore correction bymultiple comparisons was not applied Associations wereconsidered statistically significant at a nominal 119875 valuele005 Haplotype analysis was performed using PLINK andHaploview softwareThe 119905-test Chi-square test Fischer exacttest and multivariable regressions were performed using thestatistical software Stata 120 (StataCorp LP College StationTX USA)
3 Results
31 Clinical and Anthropometrical Measures General char-acteristics of the study population are shown in Table 1 Themean of age BMI glucose HbA1c triglycerides LDL-C andsystolic blood pressure were significantly higher in subjectswith diabetes as compared with control group On the otherhand the HDL-C levels were found lower in diabetic subjects(119875 lt 0001) which together show some of the metabolicabnormalities associated with T2DM Taking into accountthat obesity frequency was found higher in the control group(119875 lt 00001) it was considered as a potential confounder inmultivariate analyses
32 Genotype Frequency in Diabetic and Obese Subjects Thedistribution of the Native American (NAM) the European(EUR) and the African (AFR) individual admixture pro-portions was comparable between the diabetic subjects andcontrols (NAM 119875 = 02727 EUR 119875 = 02579 and AFR 119875 =01917) The analysis did not include the individual ancestryproportions which were not available for all the subjects
Table 2 shows genotype and allelic frequency of the poly-morphisms studied Hardy Weinberg equilibrium (HWE)test showed no deviation inside the population There wasno association with diabetes and genotype frequency foundin any of the polymorphisms studied (119875 gt 005) Howevertaking into account that the polymorphisms studied havebeen associated with obesity the genotype frequencies wereanalyzed according to obesity (Table 3) Lower frequency ofthe TT genotype in obese people was observed (47 versus
Table 1 Clinical and anthropometric characteristics of the studygroups
77) which provides a significant protection against obesity(OR 054119875 = 0012) Amarginal association but not signifi-cant (119875 = 006) was foundwith rs2071749 polymorphismandobesity Therefore subanalyses were carried out according togenetic inheritance models and diabetes and obesity statusand stratification by gender
When CC + CT genotype of the rs7211 polymorphismwas compared with TT lower frequency of TT genotypeassociated with lower BMI (TT 276 plusmn 4 versus CC + CT 29plusmn 5 119875 = 0011) and higher HDL-C levels (TT 58 plusmn 13 plusmn 4versus CC +CT 49 plusmn 12119875 = 0022) in obese subjects withoutdiabetes was found The OR revealed that TT genotype is aprotective factor against obesity in nondiabetic individuals(Table 4) In themultivariable analysis genotype (as recessivemodel) was negatively associated with BMI as well as HDL-C levels in nondiabetic subjects (Table 5) However theseassociations were not found in diabetic or diabetic obesesubjects
After gender stratification CC genotype was higher inobese women compared with nonobese women (Table 4)TT genotype was also lower in obese women (TT frequencyin obese women = 512 versus nonobese women = 923119875 = 0028) but significance was achieved when multivariateanalysis and logistic regression were carried out includinggenotype as dominant model Results showed that carryingone copy of T allele decreases the risk of obesity in women(Table 4) However the association of BMI with genotype wasweak and explains just 048 of BMI variability (Table 5)
The rs2071749 polymorphism in the HMOX1 gene wassignificantly associated with obesity when it was analyzedunder a dominantmodel (Table 6) AA carriers showed lowerBMI than AG + GG carriers and had lower risk of obesity
4 Oxidative Medicine and Cellular Longevity
Table 2 Genotype frequencies of the polymorphisms studied in diabetic patients and controls
Genepolymorphism Genotypes alleles Diabetes Controls OR (95 CI) 119875 119875 of HWE
AA 119899 () 27 (43) 54 (55) 076 (05ndash12) 0259CI confidence interval HWE Hardy-Weinberg equilibrium HMOX1 heme oxygenase-1 NQO1 NAD(P)H quinone oxidoreductase 1 NRF2 Nuclear factor-erythroid 2- (NF-E2-) related factor 2 OR odds ratio and TXNIP thioredoxin interacting protein
Table 3 Genotype and allele frequencies of the polymorphisms studied in obese and nonobese subjects
Genepolymorphism Genotype Obesity No obesity OR (95 CI) 119875
TRXNIPrs7211
CC n () 350 (566) 523 (537) ReferenceCT n () 239 (387) 376 (386) 095 (07ndash12) 0627TT n () 29 (47) 75 (77) 056 (035ndash087) 0012
NQO1rs1800566
CC n () 212 (342) 331 (333) ReferenceCT n () 302 (488) 469 (47) 1 (08ndash125) 0963TT n () 106 (17) 196 (197) 084 (06ndash11) 0257
HMOX1rs2071749
AA n () 261 (40) 419 (457) ReferenceAG n () 306 (469) 378 (413) 13 (1ndash16) 0019GG n () 85 (131) 119 (13) 11 (08ndash15) 114
NRF2rs2364723
CC n () 194 (31) 317 (32) ReferenceCG n () 300 (48) 457 (46) 11 (085ndash135) 0551GG n () 131 (21) 210 (22) 098 (07ndash13) 0899
NRF2rs6721961
CC n () 390 (631) 635 (639) ReferenceCA n () 195 (316) 311 (313) 1 (08ndash13) 0853AA n () 33 (53) 48 (48) 11 (07ndash17) 0631
CI confidence interval HMOX1 heme oxygenase-1 NQO1 NAD(P)H quinone oxidoreductase 1 NRF2 Nuclear factor-erythroid 2- (NF-E2-) related factor2 OR odds ratio and TXNIP thioredoxin interacting protein
The association of the rs2071749 polymorphism persists withobesity after being adjusted by age gender HDL-C levelsLDL-C levels and triglycerides concentrations
The rs6721961 polymorphism of the Nrf2 gene was asso-ciated with diabetes in men but not in women after strati-fication by gender (Table 7) CC carriers had higher glucoselevels in comparison with CA + CC carriers when genotypewas compared as dominant model Thus the presence ofthe A allele represents a protective factor against diabetes inmen The pairwise linkage disequilibrium (LD) analysis ofthe rs6721961 and rs2364723 in NRF2 gene revealed a low
LD between them (1199032 = 031) Additionally the analysesof potential haplotype effects showed no association withdiabetes (119875 = 074) or obesity (119875 = 052)
4 Discussion
Oxidative stress is one of themajormetabolic factors that leadto the onset of chronic disease like insulin resistance hyper-tension metabolic syndrome prediabetes diabetes and itscomplications It has been recognized that the antioxidantsystem is abated in diabetes and obesity accompanied by an
Oxidative Medicine and Cellular Longevity 5
Table 4 Genotype frequency of the rs7211 polymorphism in subjects without diabetes and women
Obese Nonobese Crude OR (95 CI) 119875 Adjusteda OR (95 CI) 119875
CI confidence interval OR odds ratioaObesity in logistic regression was adjusted by age gender (except in women model) glucose triglycerides LDL-C and HDL-C levels
Table 5 Multiple linear regression of BMI as dependent variable innondiabetic subjects and women
Models also include age gender (in nondiabetic subjectsmodel) LDL-C andtriglycerides Significant variables were presented BMI body mass indexHDL-C high-density lipoprotein cholesterol
increased production of inflammatory cytokines A defect inNrf2 activation in many organs has been documented widelyin experimental models of insulin resistance and diabetesleading to decreased expression of its target genes [31ndash34]In this study it was found that the rs6721961 (minus617CA)polymorphism of Nrf2 gene was associated with diabetes inMexican mestizo men while the rs7211 polymorphism ofTXNIP gene and the rs2071749 polymorphism of HMOX1genewere associatedwith obesity Nevertheless the polymor-phisms rs1800566 (NQO1) and rs2364723 (Nrf2) were notfound to be associated with diabetes or obesity
Wang et al [35] did not found association between thers1800566 polymorphism in NQO1 gene and the risk ofT2DM in Chinese population On the other hand Kim[36] reported that there were no associations betweenthe rs1800566 polymorphism and BMI blood pressurelipid profile HbA1c postprandial glucose and homeostasismodel assessment-insulin resistance (HOMA-IR) Neverthe-lessMartınez-Hernandez et al [18] showed that theT allele ofthe rs1800566 polymorphism was associated with increasedtriglycerides levels and decreased HDL-C levels in Mexicanmestizo individuals with metabolic syndrome However inthis study this association was not found and we suggest thatthis difference is due to the fact that 57 and 47 of the
subjects recruited in our study were under medical treatmentwith fibrates and statins respectively and attend to clinicaldetection annually
The rs7211 has been poorly studied in diabetic and obesesubjects First van Greevenbroek et al [23] found thattriglycerides levels were higher in diabetic subjects with theT allele than the C allele carriers which was associatedwith higher glucose concentrations Subsequently Ferreiraet al [24] found that the rs7211 was associated in Braziliansubjects with diabetes and hypertension and T carriersshowed higher concentrations of blood glucose and systolicblood pressure Das et al [37] reported that in European-American or African-American subjects recruited in USAthe TXNIP gene expression was negatively correlated withobesity In this study the T allele was found as a protectionfactor against metabolic traits like BMI and HDL-C TheT allele carriers showed that lower BMI values and HDL-C concentrations in nondiabetic subjects and in women arestill associated with obesity after adjustment by confoundingfactors Some authors reported that this polymorphism canincreaseTXNIP expression [22] but this still remains unclearHowever this is the first report in which it was found that Tallele is a protective factor against obesity and we suggest thatTXNIP expression or function would be affected allowingTXN to exert its antioxidant action
The SNP rs2071746 (T-413A) and (GT)119899microsatellite
are polymorphisms in the promoter region of HMOX1 genewhich canmodulate its transcriptional activity and have beenassociated with various human diseases [19] Lin et al [20]showed that the (GT)
119899repeat in the HMOX1 promoter was
significantly associated with essential hypertension systolicblood pressure and diastolic blood pressure whereas theother two SNPs rs2071746 and rs2071749 were not asso-ciated Although the rs2071749 has been poorly studiedwith metabolic traits in this study it was found that AAcarriers showed lower BMI values which were associatedwith the risk of presenting obesity whereas GG carriersshowed higher BMI values This is the first report showingthe association of the rs2071749 polymorphism and obesityThis polymorphism is an intronic tag SNP and it has reportedthat it is in LD with the rs3761439 which is located in
6 Oxidative Medicine and Cellular Longevity
Table 6 Association of the rs2071749 polymorphism of the HMOX1 gene with obesity
AA 261 (40) 410 (46) 0026 289 plusmn 49 0027AG + GG 390 (60) 497 (54) 295 plusmn 53Crude OR (95 CI) 125 (102ndash154) 0026OR adjusteda (95 CI) 134 (106ndash17) 0013Beta coefficient1198772b 0063003 0023BMI values are presented as mean plusmn SD BMI body mass index CI confidence interval and OR odds ratioaObesity in logistic regression was adjusted by age gender glucose triglycerides and LDL-C and HDL-C levels Genotype was included as dominant modelin logistic and multivariate analysisbLinear regression of BMI as dependent variable was adjusted by age gender glucose triglycerides and LDL-C and HDL-C levels
Table 7 Association of the rs6721961 polymorphism of the Nrf2 gene with diabetes in men
Crude OR (95 CI) 062 (046ndash085) 0003OR adjusteda (95 CI) 056 (038ndash082) 0003Crude beta coefficient minus0078 0031Glucose values (mgsdotdLminus1) are presented as mean plusmn SD CI confidence interval OR odds ratioaDiabetes in logistic regression was adjusted by age triglycerides and LDL-C and HDL-C levels Genotype was included as dominant model in logistic andlinear regressionb119875 value when comparing each genotype
c119875 value in comparison of CC with CA + AA
the promoter region of the HMOX1 gene The consensussequence of a nuclear factor 120581B (NF-120581B) binding site toHMOX1 is altered by rs3761439 polymorphism that increasesthe risk of developing impaired lung function [38] Thissuggests that the mechanisms by which this polymorphismcould be involved in obesity may be secondary to increasedoxidative stress and inflammation The results in this workopen the gate to new investigations about the role of theHMOX1 gene in Mexican obese patients
NRF2 gene regulates the enzymes studied here ManySNPs have been identified in this gene The rs35652124 andrs6721961 SNPs are predicted to affect Nrf2 myeloid zincfinger 1 (MZF1) and antioxidant response elements- (ARE-) like promoter binding sites respectively These SNPs affectthe efficient binding of proteins such as Nrf2 to theMZF1 andARE-like promoter binding sites [39]
In metabolic diseases the rs6721961 polymorphism hasbeen associated with blood pressure in Japanese subjects [39]Wang et al [7] showed that the rs6721961 polymorphism inthe NRF2 gene was significantly associated with oxidativestress antioxidant status and risk of newly diagnosed T2DMas well as with impaired insulin secretory capacity andincreased insulin resistance in T2DM patients of a Chinesepopulation Individuals with the CC genotype had lowertotal antioxidant capacity glutathione levels and superoxidedismutase catalase and glutathione peroxidase activitiesas well as lower homeostasis model assessment of 120573-cellfunction index (HOMA-120573) in comparison with individualswith the CC genotypeThosewith theAA genotype also had a
higher malondialdehyde concentration andHOMA-IR indexvalues The frequency of allele A was significantly higher inT2DM subjects (294) Individuals with the AA genotypehad a significantly higher risk of developing T2DM relativeto thosewith theCCgenotype even after adjusting for knownT2DM risk factors However this investigation showed thatthe AA carriers had lower glucose concentrations and theOR revealed that A carriers had lower risk of developingdiabetes in men after stratification by gender We had thelimitation that Nrf2 gene expression was not determined inthese patients and it is essential to elucidate the mechanismsby which the rs6721961 polymorphism can exert its protectiveeffect in our population Larger sample size could supportthis
We know that this research has some limitations Thegene expressions and activities were not determined and justcandidate genes were included Dietary information was notavailable in all patients However this study opens the gate tonew researches about the role of HMOX1 TXNIP and Nrf2in obesity diabetes and worse metabolic traits
5 Conclusions
This study shows that the rs7211 polymorphism in the TXNIPgene and the rs2071749 of the HMOX1 gene are associatedwith obesity in Mexican mestizo people In this sensers2071749 increases the risk of having obesity and the rs7211polymorphism may be a protective factor to develop obesityand to have lower concentrations of HDL-C in Mexican
Oxidative Medicine and Cellular Longevity 7
mestizo women In addition rs6721961 gen polymorphismin Nrf2 was negatively associated with diabetes in men Allof these results open the doors for new research taking intoaccount the effect onmetabolic traits andmay be useful toolsto design new therapeutic strategies in obesity and diabetestype 2
Competing Interests
The authors declare that they have no competing interests
Acknowledgments
The authors would like to acknowledge the Medical FamilyClinics from ISSSTE Ignacio Chavez Del Valle Xochimilcoand Fuentes Brotantes This work was financially supportedby CONACyT-Mexico (Grant no SALUD-2013-01-201519)
[2] R H Eckel S E Kahn E Ferrannini et al ldquoObesity andtype 2 diabetes what can be unified and what needs to beindividualizedrdquo Diabetes Care vol 34 no 6 pp 1424ndash14302011
[3] S Tyrovolas A Koyanagi NGarin et al ldquoDiabetesmellitus andits association with central obesity and disability among olderadults a global perspectiverdquo Experimental Gerontology vol 64pp 70ndash77 2015
[4] M Serrano-Rios ldquoRelationship between obesity and theincreased risk of major complications in non-insulin-depend-ent diabetesmellitusrdquo European Journal of Clinical Investigationvol 28 supplement 2 pp 14ndash18 1998
[5] S-I Yamagishi S Maeda T Matsui S Ueda K Fukami andS Okuda ldquoRole of advanced glycation end products (AGEs)and oxidative stress in vascular complications in diabetesrdquoBiochimica et Biophysica ActamdashGeneral Subjects vol 1820 no5 pp 663ndash671 2012
[6] Y-J Surh J K Kundu and H-K Na ldquoNrf2 as a master redoxswitch in turning on the cellular signaling involved in theinduction of cytoprotective genes by some chemopreventivephytochemicalsrdquo Planta Medica vol 74 no 13 pp 1526ndash15392008
[7] X Wang H Chen J Liu et al ldquoAssociation between the NF-E2related factor 2 gene polymorphism and oxidative stress anti-oxidative status and newly-diagnosed type 2 diabetes mellitusin a Chinese populationrdquo International Journal of MolecularSciences vol 16 no 7 pp 16483ndash16496 2015
[8] A S Jimenez-Osorio A Picazo S Gonzalez-Reyes D Barrera-Oviedo M E Rodrıguez-Arellano and J Pedraza-ChaverrildquoNrf2 and redox status in prediabetic and diabetic patientsrdquoInternational Journal of Molecular Sciences vol 15 no 11 pp20290ndash20305 2014
[9] J Pi L Leung P Xue et al ldquoDeficiency in the nuclear factorE2-related factor-2 transcription factor results in impairedadipogenesis and protects against diet-induced obesityrdquo TheJournal of Biological Chemistry vol 285 no 12 pp 9292ndash93002010
[10] H-Y Cho ldquoGenomic structure and variation of nuclear factor(erythroid-derived 2)-like 2rdquo Oxidative Medicine and CellularLongevity vol 2013 Article ID 286524 24 pages 2013
[11] Y Shimoyama Y Mitsuda N Hamajima and T Niwa ldquoPoly-morphisms of Nrf2 an antioxidative gene are associated withblood pressure in Japaneserdquo Nagoya Journal of Medical Sciencevol 76 no 1-2 pp 113ndash120 2014
[12] S M Figarska J M Vonk and H M Boezen ldquoNFE2L2polymorphisms mortality and metabolism in the generalpopulationrdquo Physiological Genomics vol 46 no 12 pp 411ndash4172014
[13] D Ross and D Siegel ldquoNAD(P)Hquinone oxidoreductase1 (NQO1 DT-diaphorase) functions and pharmacogeneticsrdquoMethods in Enzymology vol 382 pp 115ndash144 2004
[14] J-E Chung B C Chang K E Lee J H Kim and H S GwakldquoEffects of NAD(P)Hquinone oxidoreductase 1 polymorphismson stable warfarin doses in Korean patients with mechanicalcardiac valvesrdquo European Journal of Clinical Pharmacology vol71 no 10 pp 1229ndash1236 2015
[15] H-Y Shyu C-S Fong Y-P Fu et al ldquoGenotype polymor-phisms of GGCX NQO1 and VKORC1 genes associated withrisk susceptibility in patients with large-artery atheroscleroticstrokerdquo Clinica Chimica Acta vol 411 no 11-12 pp 840ndash8452010
[16] S J Han E S Kang H J Kim et al ldquoThe C609T variant ofNQO1 is associated with carotid artery plaques in patients withtype 2 diabetesrdquoMolecular Genetics andMetabolism vol 97 no1 pp 85ndash90 2009
[17] T Ramprasath P S Murugan E Kalaiarasan P GomathiA Rathinavel and G S Selvam ldquoGenetic association ofGlutathione peroxidase-1 (GPx-1) and NAD(P)Hquinone oxi-doreductase 1(NQO1) variants and their association of CAD inpatients with type-2 diabetesrdquoMolecular and Cellular Biochem-istry vol 361 no 1-2 pp 143ndash150 2012
[18] A Martınez-Hernandez E J Cordova O Rosillo-Salazar etal ldquoAssociation of HMOX1 and NQO1 polymorphisms withmetabolic syndrome componentsrdquo PLoS ONE vol 10 no 5Article ID e0123313 2015
[19] E Y Lee Y H Lee S H Kim et al ldquoAssociation between hemeoxygenase-1 promoter polymorphisms and the development ofalbuminuria in type 2 diabetes a case-control studyrdquoMedicinevol 94 no 43 article e1825 2015
[20] R Lin W Fu W Zhou et al ldquoAssociation of heme oxygenase-1 gene polymorphisms with essential hypertension and bloodpressure in the Chinese Han populationrdquo Genetic Testing andMolecular Biomarkers vol 15 no 1-2 pp 23ndash28 2011
[21] E Junn S H Han J Y Im et al ldquoVitamin D3 up-regulated pro-tein 1 mediates oxidative stress via suppressing the thioredoxinfunctionrdquoThe Journal of Immunology vol 164 no 12 pp 6287ndash6295 2000
[22] X He and QMa ldquoRedox regulation by nuclear factor erythroid2-related factor 2 gatekeeping for the basal and diabetes-induced expression of thioredoxin-interacting proteinrdquo Molec-ular Pharmacology vol 82 no 5 pp 887ndash897 2012
[23] M M J van Greevenbroek V M M-J Vermeulen E J MFeskens et al ldquoGenetic variation in thioredoxin interactingprotein (TXNIP) is associated with hypertriglyceridaemia andblood pressure in diabetes mellitusrdquo Diabetic Medicine vol 24no 5 pp 498ndash504 2007
[24] N E Ferreira S Omae A Pereira et al ldquoThioredoxin inter-acting protein genetic variation is associated with diabetes and
8 Oxidative Medicine and Cellular Longevity
hypertension in the Brazilian general populationrdquoAtherosclero-sis vol 221 no 1 pp 131ndash136 2012
[25] J Grimberg S Nawoschik L Belluscio R McKee A Turckand A Eisenberg ldquoA simple and efficient non-organic proce-dure for the isolation of genomic DNA from bloodrdquo NucleicAcids Research vol 17 no 20 p 8390 1989
[26] J Zuniga N Yu R Barquera et al ldquoHLA class I and class IIconserved extended haplotypes and their fragments or blocksin mexicans implications for the study of genetic diversityin admixed populationsrdquo PLoS ONE vol 8 no 9 Article IDe74442 2013
[27] P Sanz V Prieto I Flores Y Torres M Lopez-Soto andM J Farfan ldquoPopulation data of 13 STRS in southern Spain(Andalusia)rdquo Forensic Science International vol 119 no 1 pp113ndash115 2001
[28] P Calzada I Suarez S Garcıa et al ldquoThe Fang populationof Equatorial Guinea characterised by 15 STR-PCR polymor-phismsrdquo International Journal of Legal Medicine vol 119 no 2pp 107ndash110 2005
[29] C Barrot C Sanchez M Ortega et al ldquoCharacterisation ofthree Amerindian populations from Hidalgo State (Mexico)by 15 STR-PCR polymorphismsrdquo International Journal of LegalMedicine vol 119 no 2 pp 111ndash115 2005
[30] A Gonzalez-Martın A Gorostiza H Rangel-Villalobos et alldquoAnalyzing the genetic structure of the Tepehua in relation toother neighbouring Mesoamerican populations A study basedon allele frequencies of STR markersrdquo American Journal ofHuman Biology vol 20 no 5 pp 605ndash613 2008
[31] Y Tan T Ichikawa J Li et al ldquoDiabetic downregulation of Nrf2activity via ERK contributes to oxidative stress-induced insulinresistance in cardiac cells in vitro and in vivordquoDiabetes vol 60no 2 pp 625ndash633 2011
[32] H-A Seo and I-K Lee ldquoThe role of NRF2 adipocyte differen-tiation obesity and insulin resistancerdquo Oxidative Medicine andCellular Longevity vol 2013 Article ID 184598 7 pages 2013
[33] J Xu A C Donepudi V R More et al ldquoDeficiency in Nrf2transcription factor decreases adipose tissue mass and hepaticlipid accumulation in leptin-deficientmicerdquoObesity vol 23 no2 pp 335ndash344 2015
[34] A Uruno Y Yagishita and M Yamamoto ldquoThe Keap1-Nrf2system and diabetes mellitusrdquo Archives of Biochemistry andBiophysics vol 566 pp 76ndash84 2015
[35] G Wang L Zhang and Q Li ldquoGenetic polymorphisms ofGSTT1 GSTM1 and NQO1 genes and diabetes mellitus riskin Chinese populationrdquo Biochemical and Biophysical ResearchCommunications vol 341 no 2 pp 310ndash313 2006
[36] D Kim ldquoAn association between 609 CrarrT Polymorphism inNAD(P)Hquinone oxidoreductase 1 (NQO1) gene and bloodglucose levels in Korean populationrdquo Korean Diabetes Journalvol 33 no 1 pp 24ndash30 2009
[37] S K Das N K Sharma S J Hasstedt et al ldquoAn integra-tive genomics approach identifies activation of thioredoxinthioredoxin reductase-1-mediated oxidative stress defense path-way and inhibition of angiogenesis in obese nondiabetic humansubjectsrdquo The Journal of Clinical Endocrinology amp Metabolismvol 96 no 8 pp E1308ndashE1313 2011
[38] G Tanaka F Aminuddin L Akhabir et al ldquoEffect of hemeoxygenase-1 polymorphisms on lung function and gene expres-sionrdquo BMCMedical Genetics vol 12 article 117 2011
[39] Y Shimoyama Y Mitsuda Y Tsuruta N Hamajima andT Niwa ldquoPolymorphism of Nrf2 an antioxidative gene is
associated with blood pressure and cardiovascular mortalityin hemodialysis patientsrdquo International Journal of MedicalSciences vol 11 no 7 pp 726ndash731 2014
of the caprsquonrsquocollar family of basic leucine zipper transcrip-tion factors that regulates the expression of many antiox-idant genes including NAD(P)Hquinone oxidoreductase 1(NQO1) and heme oxygenase-1 (HMOX1) to avoid oxidativedamage [6] Also it has been demonstrated that Nrf2 activityis abated in diabetes and factors like age body weight andblood glucose could modify its activity [7ndash9] but geneticfactors have been poorly studied Many single nucleotidepolymorphisms (SNPs) have been identified in the Nrf2 gene[10] In particular the rs6721961 (C-617C) polymorphismhas been associated with oxidative stress and risk of newlydiagnosed T2DM [7] and increased blood pressure [11]The rs2364723 (C107G) polymorphism was associated withreduced risk of cardiovascular mortality [12] The NQO1gene polymorphism rs1800566 (C609T) is characterized bythe replacement of proline by serine at position number187 of the functional protein which causes destabilizationand inactivation of the enzyme [13 14] The rs1800566polymorphism has been associated with lower levels of bloodcoagulation factors [15] higher risk of coronary artery diseasein T2DM patients [16 17] and increased triglycerides levelsand decreased HDL-C levels in individuals with metabolicsyndrome [18] Polymorphisms in the promoter region ofthe HMOX1 gene such as rs2071746 (T-413A) and (GT)
119899
microsatellite have been associated with various humandiseases [19] however the rs2071749 polymorphism (AG)is not associated with hypertension andor blood pressurein hypertensive patients [20] It has been reported that theendogenous inhibitor of the thioredoxin (TXN) system thethioredoxin interacting protein (TXNIP) can be suppressedby Nrf2 [21 22] The rs7211 polymorphism in TXNIP wasassociated with inhibition of TNX glucose homeostasisdiabetes and hypertension [23] Individuals carrying the Tallele of the rs7211 polymorphism in the TXNIP gene showedhigher plasma triglycerides levels [24]
However despite the recent efforts to understand theassociation of antioxidant gene polymorphism with T2DMthe number of studies is still very limited in Mexican popu-lationThus the aim of this study was to investigate potentialassociations between Nrf2 (rs6721961 and rs2364723) NQO1(rs1800566) HMOX1 (rs2071749) and TXNIP (rs7211) poly-morphisms in a T2DM population
2 Materials and Methods
21 Study Design and Subjects A case control study wasperformed which included 1647 Mexican mestizo subjectsThis study was approved by the Ethics Committee on HumanStudies from the Committee on Research Ethics and Safetyof the Hospital Regional ldquoLic Adolfo Lopez Mateosrdquo withregistration number 2542013 and conducted in accordancewith the Declaration of Helsinki Written informed consentwas obtained from all subjects who were recruited in FamilyMedical Clinics of the Instituto de Seguridad y ServiciosSociales de los Trabajadores del Estado (ISSSTE) in MexicoCity
A standard questionnaire was applied to obtain demo-graphic information family and personal health history(diabetes andor further diseases) and information about
physical activity alcohol consumption smoking and drugsconsumption Their medical history data weight (kg) andheight (m) were obtained The body mass index (BMI)was estimated by dividing weight by the square of heightCriteria for inclusionexclusion of participants were as fol-lows the study included men and women aged 35 andolder nonpregnant and nonlactating women and subjectswithout excessive alcohol consumption The criteria forclassification and diagnosis of diabetes were according tothe standards in medical care on diabetes from AmericanDiabetes Association (ADA) Subjects of the control group(119899 = 1020) had fasting glucose lt55mmolL and glycatedhemoglobin (HbA1c) lt57 Subjects with T2DM (119899 = 627)had plasma glucose gt70mmolL and HbA1c gt65 Subjectswithmental health problems (senile dementia andAlzheimerand Parkinsonrsquos disease) and cancer were also excluded Therecruitment period was from May 2012 to October 2014 Atotal of 1627 individuals were recruited that self-reportedMexican mestizo ancestry (three generations) To each indi-vidual the information was given about the protocol andthose who decided to enter gave written informed consentto participate Anthropometric data (waist circumferenceheight and weight) and arterial pressure measurements wereobtained before blood collection
22 Blood Collection and Biochemical Analyses Whole bloodsamples (20mL) were collected from patients and controls(with fasting of 8ndash12 h) in order to determine the levels ofglucose triglycerides total cholesterol HDL-C low-densitylipoprotein cholesterol (LDL-C) and creatinine in serumusing an automatized analyzer (Miura 200 ISE RomeItaly) Moreover total blood with ethylenediaminetetraacetic(EDTA) acid as anticoagulant was used to obtain genomicDNA
23 Genotyping Genomic DNA from whole blood con-taining EDTA was isolated by standard techniques [25]The rs2364723 (Nrf2) rs1800566 (NQO1) rs7211 (TXNIP)and rs2071749 (HMOX1) SNPs were genotyped using pre-designed 51015840 exonuclease TaqMan genotyping assays on a 7500series Real-Time PCR system according to manufacturerrsquosinstructions (Applied Biosystems Foster City CA USA)Thers6721961 (Nrf2) TaqMan probe was designed according tomanufacturerrsquos directions
24 Short Tandem Repeats (STRs) Genotyping and AdmixtureEstimations Fifteen autosomal STRmarkers (CSF1PO FGATHO1 TPOX VWA D3S11358 D5S818 D7S820 D8S1179D13S317 D16S539 D18S51 D21S11 D19S433 and D2S1338)along with amelogenin were genotyped in 200 controls and200 cases using the AmpFlSTR Identifiler Kit (AppliedBiosystems Foster City CA USA) as previously described[26]
We performed admixture estimations using the STRrsquosallele distribution by a model-based clustering method withthe Structure software v 234 assuming 119896 = 3 populationsand 1 times 104 dememorisation steps The estimations ofAmerindian European andAfrican components in ourMex-ican studied groups were performed using the distribution of
Oxidative Medicine and Cellular Longevity 3
STRs alleles in different populations including Spaniards [27]Fang Africans [28] and a Native American pool of Huastecos[29] and Tepehuas [30] from the central region of Mexicowho were considered as parental populations
25 Statistical Analyses Continuous variables were analyzedusing a 119905-test and were presented as mean plusmn standarddeviation (SD) For categorical variables a Chi-square testor Fischer exact test was applied and data was presented aspercentage
The Hardy Weinberg equilibrium was calculated in con-trols using StatCalc software (Epi Info 2005 v332 Centersof Disease Control and Prevention Atlanta GA USA)Multivariable linear regression models were carried out foradjustment of glucose for potential confounders like agegender BMI and tobacco In order to assess the genetic riskfactor for diabetes and obesity logistic regression analyseswere applied to estimate the OR for each polymorphismBecause the associations between the SNPs and the outcomeshave been previously reported it is unlikely to detect effectsdue to statistical fluctuations only Therefore correction bymultiple comparisons was not applied Associations wereconsidered statistically significant at a nominal 119875 valuele005 Haplotype analysis was performed using PLINK andHaploview softwareThe 119905-test Chi-square test Fischer exacttest and multivariable regressions were performed using thestatistical software Stata 120 (StataCorp LP College StationTX USA)
3 Results
31 Clinical and Anthropometrical Measures General char-acteristics of the study population are shown in Table 1 Themean of age BMI glucose HbA1c triglycerides LDL-C andsystolic blood pressure were significantly higher in subjectswith diabetes as compared with control group On the otherhand the HDL-C levels were found lower in diabetic subjects(119875 lt 0001) which together show some of the metabolicabnormalities associated with T2DM Taking into accountthat obesity frequency was found higher in the control group(119875 lt 00001) it was considered as a potential confounder inmultivariate analyses
32 Genotype Frequency in Diabetic and Obese Subjects Thedistribution of the Native American (NAM) the European(EUR) and the African (AFR) individual admixture pro-portions was comparable between the diabetic subjects andcontrols (NAM 119875 = 02727 EUR 119875 = 02579 and AFR 119875 =01917) The analysis did not include the individual ancestryproportions which were not available for all the subjects
Table 2 shows genotype and allelic frequency of the poly-morphisms studied Hardy Weinberg equilibrium (HWE)test showed no deviation inside the population There wasno association with diabetes and genotype frequency foundin any of the polymorphisms studied (119875 gt 005) Howevertaking into account that the polymorphisms studied havebeen associated with obesity the genotype frequencies wereanalyzed according to obesity (Table 3) Lower frequency ofthe TT genotype in obese people was observed (47 versus
Table 1 Clinical and anthropometric characteristics of the studygroups
77) which provides a significant protection against obesity(OR 054119875 = 0012) Amarginal association but not signifi-cant (119875 = 006) was foundwith rs2071749 polymorphismandobesity Therefore subanalyses were carried out according togenetic inheritance models and diabetes and obesity statusand stratification by gender
When CC + CT genotype of the rs7211 polymorphismwas compared with TT lower frequency of TT genotypeassociated with lower BMI (TT 276 plusmn 4 versus CC + CT 29plusmn 5 119875 = 0011) and higher HDL-C levels (TT 58 plusmn 13 plusmn 4versus CC +CT 49 plusmn 12119875 = 0022) in obese subjects withoutdiabetes was found The OR revealed that TT genotype is aprotective factor against obesity in nondiabetic individuals(Table 4) In themultivariable analysis genotype (as recessivemodel) was negatively associated with BMI as well as HDL-C levels in nondiabetic subjects (Table 5) However theseassociations were not found in diabetic or diabetic obesesubjects
After gender stratification CC genotype was higher inobese women compared with nonobese women (Table 4)TT genotype was also lower in obese women (TT frequencyin obese women = 512 versus nonobese women = 923119875 = 0028) but significance was achieved when multivariateanalysis and logistic regression were carried out includinggenotype as dominant model Results showed that carryingone copy of T allele decreases the risk of obesity in women(Table 4) However the association of BMI with genotype wasweak and explains just 048 of BMI variability (Table 5)
The rs2071749 polymorphism in the HMOX1 gene wassignificantly associated with obesity when it was analyzedunder a dominantmodel (Table 6) AA carriers showed lowerBMI than AG + GG carriers and had lower risk of obesity
4 Oxidative Medicine and Cellular Longevity
Table 2 Genotype frequencies of the polymorphisms studied in diabetic patients and controls
Genepolymorphism Genotypes alleles Diabetes Controls OR (95 CI) 119875 119875 of HWE
AA 119899 () 27 (43) 54 (55) 076 (05ndash12) 0259CI confidence interval HWE Hardy-Weinberg equilibrium HMOX1 heme oxygenase-1 NQO1 NAD(P)H quinone oxidoreductase 1 NRF2 Nuclear factor-erythroid 2- (NF-E2-) related factor 2 OR odds ratio and TXNIP thioredoxin interacting protein
Table 3 Genotype and allele frequencies of the polymorphisms studied in obese and nonobese subjects
Genepolymorphism Genotype Obesity No obesity OR (95 CI) 119875
TRXNIPrs7211
CC n () 350 (566) 523 (537) ReferenceCT n () 239 (387) 376 (386) 095 (07ndash12) 0627TT n () 29 (47) 75 (77) 056 (035ndash087) 0012
NQO1rs1800566
CC n () 212 (342) 331 (333) ReferenceCT n () 302 (488) 469 (47) 1 (08ndash125) 0963TT n () 106 (17) 196 (197) 084 (06ndash11) 0257
HMOX1rs2071749
AA n () 261 (40) 419 (457) ReferenceAG n () 306 (469) 378 (413) 13 (1ndash16) 0019GG n () 85 (131) 119 (13) 11 (08ndash15) 114
NRF2rs2364723
CC n () 194 (31) 317 (32) ReferenceCG n () 300 (48) 457 (46) 11 (085ndash135) 0551GG n () 131 (21) 210 (22) 098 (07ndash13) 0899
NRF2rs6721961
CC n () 390 (631) 635 (639) ReferenceCA n () 195 (316) 311 (313) 1 (08ndash13) 0853AA n () 33 (53) 48 (48) 11 (07ndash17) 0631
CI confidence interval HMOX1 heme oxygenase-1 NQO1 NAD(P)H quinone oxidoreductase 1 NRF2 Nuclear factor-erythroid 2- (NF-E2-) related factor2 OR odds ratio and TXNIP thioredoxin interacting protein
The association of the rs2071749 polymorphism persists withobesity after being adjusted by age gender HDL-C levelsLDL-C levels and triglycerides concentrations
The rs6721961 polymorphism of the Nrf2 gene was asso-ciated with diabetes in men but not in women after strati-fication by gender (Table 7) CC carriers had higher glucoselevels in comparison with CA + CC carriers when genotypewas compared as dominant model Thus the presence ofthe A allele represents a protective factor against diabetes inmen The pairwise linkage disequilibrium (LD) analysis ofthe rs6721961 and rs2364723 in NRF2 gene revealed a low
LD between them (1199032 = 031) Additionally the analysesof potential haplotype effects showed no association withdiabetes (119875 = 074) or obesity (119875 = 052)
4 Discussion
Oxidative stress is one of themajormetabolic factors that leadto the onset of chronic disease like insulin resistance hyper-tension metabolic syndrome prediabetes diabetes and itscomplications It has been recognized that the antioxidantsystem is abated in diabetes and obesity accompanied by an
Oxidative Medicine and Cellular Longevity 5
Table 4 Genotype frequency of the rs7211 polymorphism in subjects without diabetes and women
Obese Nonobese Crude OR (95 CI) 119875 Adjusteda OR (95 CI) 119875
CI confidence interval OR odds ratioaObesity in logistic regression was adjusted by age gender (except in women model) glucose triglycerides LDL-C and HDL-C levels
Table 5 Multiple linear regression of BMI as dependent variable innondiabetic subjects and women
Models also include age gender (in nondiabetic subjectsmodel) LDL-C andtriglycerides Significant variables were presented BMI body mass indexHDL-C high-density lipoprotein cholesterol
increased production of inflammatory cytokines A defect inNrf2 activation in many organs has been documented widelyin experimental models of insulin resistance and diabetesleading to decreased expression of its target genes [31ndash34]In this study it was found that the rs6721961 (minus617CA)polymorphism of Nrf2 gene was associated with diabetes inMexican mestizo men while the rs7211 polymorphism ofTXNIP gene and the rs2071749 polymorphism of HMOX1genewere associatedwith obesity Nevertheless the polymor-phisms rs1800566 (NQO1) and rs2364723 (Nrf2) were notfound to be associated with diabetes or obesity
Wang et al [35] did not found association between thers1800566 polymorphism in NQO1 gene and the risk ofT2DM in Chinese population On the other hand Kim[36] reported that there were no associations betweenthe rs1800566 polymorphism and BMI blood pressurelipid profile HbA1c postprandial glucose and homeostasismodel assessment-insulin resistance (HOMA-IR) Neverthe-lessMartınez-Hernandez et al [18] showed that theT allele ofthe rs1800566 polymorphism was associated with increasedtriglycerides levels and decreased HDL-C levels in Mexicanmestizo individuals with metabolic syndrome However inthis study this association was not found and we suggest thatthis difference is due to the fact that 57 and 47 of the
subjects recruited in our study were under medical treatmentwith fibrates and statins respectively and attend to clinicaldetection annually
The rs7211 has been poorly studied in diabetic and obesesubjects First van Greevenbroek et al [23] found thattriglycerides levels were higher in diabetic subjects with theT allele than the C allele carriers which was associatedwith higher glucose concentrations Subsequently Ferreiraet al [24] found that the rs7211 was associated in Braziliansubjects with diabetes and hypertension and T carriersshowed higher concentrations of blood glucose and systolicblood pressure Das et al [37] reported that in European-American or African-American subjects recruited in USAthe TXNIP gene expression was negatively correlated withobesity In this study the T allele was found as a protectionfactor against metabolic traits like BMI and HDL-C TheT allele carriers showed that lower BMI values and HDL-C concentrations in nondiabetic subjects and in women arestill associated with obesity after adjustment by confoundingfactors Some authors reported that this polymorphism canincreaseTXNIP expression [22] but this still remains unclearHowever this is the first report in which it was found that Tallele is a protective factor against obesity and we suggest thatTXNIP expression or function would be affected allowingTXN to exert its antioxidant action
The SNP rs2071746 (T-413A) and (GT)119899microsatellite
are polymorphisms in the promoter region of HMOX1 genewhich canmodulate its transcriptional activity and have beenassociated with various human diseases [19] Lin et al [20]showed that the (GT)
119899repeat in the HMOX1 promoter was
significantly associated with essential hypertension systolicblood pressure and diastolic blood pressure whereas theother two SNPs rs2071746 and rs2071749 were not asso-ciated Although the rs2071749 has been poorly studiedwith metabolic traits in this study it was found that AAcarriers showed lower BMI values which were associatedwith the risk of presenting obesity whereas GG carriersshowed higher BMI values This is the first report showingthe association of the rs2071749 polymorphism and obesityThis polymorphism is an intronic tag SNP and it has reportedthat it is in LD with the rs3761439 which is located in
6 Oxidative Medicine and Cellular Longevity
Table 6 Association of the rs2071749 polymorphism of the HMOX1 gene with obesity
AA 261 (40) 410 (46) 0026 289 plusmn 49 0027AG + GG 390 (60) 497 (54) 295 plusmn 53Crude OR (95 CI) 125 (102ndash154) 0026OR adjusteda (95 CI) 134 (106ndash17) 0013Beta coefficient1198772b 0063003 0023BMI values are presented as mean plusmn SD BMI body mass index CI confidence interval and OR odds ratioaObesity in logistic regression was adjusted by age gender glucose triglycerides and LDL-C and HDL-C levels Genotype was included as dominant modelin logistic and multivariate analysisbLinear regression of BMI as dependent variable was adjusted by age gender glucose triglycerides and LDL-C and HDL-C levels
Table 7 Association of the rs6721961 polymorphism of the Nrf2 gene with diabetes in men
Crude OR (95 CI) 062 (046ndash085) 0003OR adjusteda (95 CI) 056 (038ndash082) 0003Crude beta coefficient minus0078 0031Glucose values (mgsdotdLminus1) are presented as mean plusmn SD CI confidence interval OR odds ratioaDiabetes in logistic regression was adjusted by age triglycerides and LDL-C and HDL-C levels Genotype was included as dominant model in logistic andlinear regressionb119875 value when comparing each genotype
c119875 value in comparison of CC with CA + AA
the promoter region of the HMOX1 gene The consensussequence of a nuclear factor 120581B (NF-120581B) binding site toHMOX1 is altered by rs3761439 polymorphism that increasesthe risk of developing impaired lung function [38] Thissuggests that the mechanisms by which this polymorphismcould be involved in obesity may be secondary to increasedoxidative stress and inflammation The results in this workopen the gate to new investigations about the role of theHMOX1 gene in Mexican obese patients
NRF2 gene regulates the enzymes studied here ManySNPs have been identified in this gene The rs35652124 andrs6721961 SNPs are predicted to affect Nrf2 myeloid zincfinger 1 (MZF1) and antioxidant response elements- (ARE-) like promoter binding sites respectively These SNPs affectthe efficient binding of proteins such as Nrf2 to theMZF1 andARE-like promoter binding sites [39]
In metabolic diseases the rs6721961 polymorphism hasbeen associated with blood pressure in Japanese subjects [39]Wang et al [7] showed that the rs6721961 polymorphism inthe NRF2 gene was significantly associated with oxidativestress antioxidant status and risk of newly diagnosed T2DMas well as with impaired insulin secretory capacity andincreased insulin resistance in T2DM patients of a Chinesepopulation Individuals with the CC genotype had lowertotal antioxidant capacity glutathione levels and superoxidedismutase catalase and glutathione peroxidase activitiesas well as lower homeostasis model assessment of 120573-cellfunction index (HOMA-120573) in comparison with individualswith the CC genotypeThosewith theAA genotype also had a
higher malondialdehyde concentration andHOMA-IR indexvalues The frequency of allele A was significantly higher inT2DM subjects (294) Individuals with the AA genotypehad a significantly higher risk of developing T2DM relativeto thosewith theCCgenotype even after adjusting for knownT2DM risk factors However this investigation showed thatthe AA carriers had lower glucose concentrations and theOR revealed that A carriers had lower risk of developingdiabetes in men after stratification by gender We had thelimitation that Nrf2 gene expression was not determined inthese patients and it is essential to elucidate the mechanismsby which the rs6721961 polymorphism can exert its protectiveeffect in our population Larger sample size could supportthis
We know that this research has some limitations Thegene expressions and activities were not determined and justcandidate genes were included Dietary information was notavailable in all patients However this study opens the gate tonew researches about the role of HMOX1 TXNIP and Nrf2in obesity diabetes and worse metabolic traits
5 Conclusions
This study shows that the rs7211 polymorphism in the TXNIPgene and the rs2071749 of the HMOX1 gene are associatedwith obesity in Mexican mestizo people In this sensers2071749 increases the risk of having obesity and the rs7211polymorphism may be a protective factor to develop obesityand to have lower concentrations of HDL-C in Mexican
Oxidative Medicine and Cellular Longevity 7
mestizo women In addition rs6721961 gen polymorphismin Nrf2 was negatively associated with diabetes in men Allof these results open the doors for new research taking intoaccount the effect onmetabolic traits andmay be useful toolsto design new therapeutic strategies in obesity and diabetestype 2
Competing Interests
The authors declare that they have no competing interests
Acknowledgments
The authors would like to acknowledge the Medical FamilyClinics from ISSSTE Ignacio Chavez Del Valle Xochimilcoand Fuentes Brotantes This work was financially supportedby CONACyT-Mexico (Grant no SALUD-2013-01-201519)
[2] R H Eckel S E Kahn E Ferrannini et al ldquoObesity andtype 2 diabetes what can be unified and what needs to beindividualizedrdquo Diabetes Care vol 34 no 6 pp 1424ndash14302011
[3] S Tyrovolas A Koyanagi NGarin et al ldquoDiabetesmellitus andits association with central obesity and disability among olderadults a global perspectiverdquo Experimental Gerontology vol 64pp 70ndash77 2015
[4] M Serrano-Rios ldquoRelationship between obesity and theincreased risk of major complications in non-insulin-depend-ent diabetesmellitusrdquo European Journal of Clinical Investigationvol 28 supplement 2 pp 14ndash18 1998
[5] S-I Yamagishi S Maeda T Matsui S Ueda K Fukami andS Okuda ldquoRole of advanced glycation end products (AGEs)and oxidative stress in vascular complications in diabetesrdquoBiochimica et Biophysica ActamdashGeneral Subjects vol 1820 no5 pp 663ndash671 2012
[6] Y-J Surh J K Kundu and H-K Na ldquoNrf2 as a master redoxswitch in turning on the cellular signaling involved in theinduction of cytoprotective genes by some chemopreventivephytochemicalsrdquo Planta Medica vol 74 no 13 pp 1526ndash15392008
[7] X Wang H Chen J Liu et al ldquoAssociation between the NF-E2related factor 2 gene polymorphism and oxidative stress anti-oxidative status and newly-diagnosed type 2 diabetes mellitusin a Chinese populationrdquo International Journal of MolecularSciences vol 16 no 7 pp 16483ndash16496 2015
[8] A S Jimenez-Osorio A Picazo S Gonzalez-Reyes D Barrera-Oviedo M E Rodrıguez-Arellano and J Pedraza-ChaverrildquoNrf2 and redox status in prediabetic and diabetic patientsrdquoInternational Journal of Molecular Sciences vol 15 no 11 pp20290ndash20305 2014
[9] J Pi L Leung P Xue et al ldquoDeficiency in the nuclear factorE2-related factor-2 transcription factor results in impairedadipogenesis and protects against diet-induced obesityrdquo TheJournal of Biological Chemistry vol 285 no 12 pp 9292ndash93002010
[10] H-Y Cho ldquoGenomic structure and variation of nuclear factor(erythroid-derived 2)-like 2rdquo Oxidative Medicine and CellularLongevity vol 2013 Article ID 286524 24 pages 2013
[11] Y Shimoyama Y Mitsuda N Hamajima and T Niwa ldquoPoly-morphisms of Nrf2 an antioxidative gene are associated withblood pressure in Japaneserdquo Nagoya Journal of Medical Sciencevol 76 no 1-2 pp 113ndash120 2014
[12] S M Figarska J M Vonk and H M Boezen ldquoNFE2L2polymorphisms mortality and metabolism in the generalpopulationrdquo Physiological Genomics vol 46 no 12 pp 411ndash4172014
[13] D Ross and D Siegel ldquoNAD(P)Hquinone oxidoreductase1 (NQO1 DT-diaphorase) functions and pharmacogeneticsrdquoMethods in Enzymology vol 382 pp 115ndash144 2004
[14] J-E Chung B C Chang K E Lee J H Kim and H S GwakldquoEffects of NAD(P)Hquinone oxidoreductase 1 polymorphismson stable warfarin doses in Korean patients with mechanicalcardiac valvesrdquo European Journal of Clinical Pharmacology vol71 no 10 pp 1229ndash1236 2015
[15] H-Y Shyu C-S Fong Y-P Fu et al ldquoGenotype polymor-phisms of GGCX NQO1 and VKORC1 genes associated withrisk susceptibility in patients with large-artery atheroscleroticstrokerdquo Clinica Chimica Acta vol 411 no 11-12 pp 840ndash8452010
[16] S J Han E S Kang H J Kim et al ldquoThe C609T variant ofNQO1 is associated with carotid artery plaques in patients withtype 2 diabetesrdquoMolecular Genetics andMetabolism vol 97 no1 pp 85ndash90 2009
[17] T Ramprasath P S Murugan E Kalaiarasan P GomathiA Rathinavel and G S Selvam ldquoGenetic association ofGlutathione peroxidase-1 (GPx-1) and NAD(P)Hquinone oxi-doreductase 1(NQO1) variants and their association of CAD inpatients with type-2 diabetesrdquoMolecular and Cellular Biochem-istry vol 361 no 1-2 pp 143ndash150 2012
[18] A Martınez-Hernandez E J Cordova O Rosillo-Salazar etal ldquoAssociation of HMOX1 and NQO1 polymorphisms withmetabolic syndrome componentsrdquo PLoS ONE vol 10 no 5Article ID e0123313 2015
[19] E Y Lee Y H Lee S H Kim et al ldquoAssociation between hemeoxygenase-1 promoter polymorphisms and the development ofalbuminuria in type 2 diabetes a case-control studyrdquoMedicinevol 94 no 43 article e1825 2015
[20] R Lin W Fu W Zhou et al ldquoAssociation of heme oxygenase-1 gene polymorphisms with essential hypertension and bloodpressure in the Chinese Han populationrdquo Genetic Testing andMolecular Biomarkers vol 15 no 1-2 pp 23ndash28 2011
[21] E Junn S H Han J Y Im et al ldquoVitamin D3 up-regulated pro-tein 1 mediates oxidative stress via suppressing the thioredoxinfunctionrdquoThe Journal of Immunology vol 164 no 12 pp 6287ndash6295 2000
[22] X He and QMa ldquoRedox regulation by nuclear factor erythroid2-related factor 2 gatekeeping for the basal and diabetes-induced expression of thioredoxin-interacting proteinrdquo Molec-ular Pharmacology vol 82 no 5 pp 887ndash897 2012
[23] M M J van Greevenbroek V M M-J Vermeulen E J MFeskens et al ldquoGenetic variation in thioredoxin interactingprotein (TXNIP) is associated with hypertriglyceridaemia andblood pressure in diabetes mellitusrdquo Diabetic Medicine vol 24no 5 pp 498ndash504 2007
[24] N E Ferreira S Omae A Pereira et al ldquoThioredoxin inter-acting protein genetic variation is associated with diabetes and
8 Oxidative Medicine and Cellular Longevity
hypertension in the Brazilian general populationrdquoAtherosclero-sis vol 221 no 1 pp 131ndash136 2012
[25] J Grimberg S Nawoschik L Belluscio R McKee A Turckand A Eisenberg ldquoA simple and efficient non-organic proce-dure for the isolation of genomic DNA from bloodrdquo NucleicAcids Research vol 17 no 20 p 8390 1989
[26] J Zuniga N Yu R Barquera et al ldquoHLA class I and class IIconserved extended haplotypes and their fragments or blocksin mexicans implications for the study of genetic diversityin admixed populationsrdquo PLoS ONE vol 8 no 9 Article IDe74442 2013
[27] P Sanz V Prieto I Flores Y Torres M Lopez-Soto andM J Farfan ldquoPopulation data of 13 STRS in southern Spain(Andalusia)rdquo Forensic Science International vol 119 no 1 pp113ndash115 2001
[28] P Calzada I Suarez S Garcıa et al ldquoThe Fang populationof Equatorial Guinea characterised by 15 STR-PCR polymor-phismsrdquo International Journal of Legal Medicine vol 119 no 2pp 107ndash110 2005
[29] C Barrot C Sanchez M Ortega et al ldquoCharacterisation ofthree Amerindian populations from Hidalgo State (Mexico)by 15 STR-PCR polymorphismsrdquo International Journal of LegalMedicine vol 119 no 2 pp 111ndash115 2005
[30] A Gonzalez-Martın A Gorostiza H Rangel-Villalobos et alldquoAnalyzing the genetic structure of the Tepehua in relation toother neighbouring Mesoamerican populations A study basedon allele frequencies of STR markersrdquo American Journal ofHuman Biology vol 20 no 5 pp 605ndash613 2008
[31] Y Tan T Ichikawa J Li et al ldquoDiabetic downregulation of Nrf2activity via ERK contributes to oxidative stress-induced insulinresistance in cardiac cells in vitro and in vivordquoDiabetes vol 60no 2 pp 625ndash633 2011
[32] H-A Seo and I-K Lee ldquoThe role of NRF2 adipocyte differen-tiation obesity and insulin resistancerdquo Oxidative Medicine andCellular Longevity vol 2013 Article ID 184598 7 pages 2013
[33] J Xu A C Donepudi V R More et al ldquoDeficiency in Nrf2transcription factor decreases adipose tissue mass and hepaticlipid accumulation in leptin-deficientmicerdquoObesity vol 23 no2 pp 335ndash344 2015
[34] A Uruno Y Yagishita and M Yamamoto ldquoThe Keap1-Nrf2system and diabetes mellitusrdquo Archives of Biochemistry andBiophysics vol 566 pp 76ndash84 2015
[35] G Wang L Zhang and Q Li ldquoGenetic polymorphisms ofGSTT1 GSTM1 and NQO1 genes and diabetes mellitus riskin Chinese populationrdquo Biochemical and Biophysical ResearchCommunications vol 341 no 2 pp 310ndash313 2006
[36] D Kim ldquoAn association between 609 CrarrT Polymorphism inNAD(P)Hquinone oxidoreductase 1 (NQO1) gene and bloodglucose levels in Korean populationrdquo Korean Diabetes Journalvol 33 no 1 pp 24ndash30 2009
[37] S K Das N K Sharma S J Hasstedt et al ldquoAn integra-tive genomics approach identifies activation of thioredoxinthioredoxin reductase-1-mediated oxidative stress defense path-way and inhibition of angiogenesis in obese nondiabetic humansubjectsrdquo The Journal of Clinical Endocrinology amp Metabolismvol 96 no 8 pp E1308ndashE1313 2011
[38] G Tanaka F Aminuddin L Akhabir et al ldquoEffect of hemeoxygenase-1 polymorphisms on lung function and gene expres-sionrdquo BMCMedical Genetics vol 12 article 117 2011
[39] Y Shimoyama Y Mitsuda Y Tsuruta N Hamajima andT Niwa ldquoPolymorphism of Nrf2 an antioxidative gene is
associated with blood pressure and cardiovascular mortalityin hemodialysis patientsrdquo International Journal of MedicalSciences vol 11 no 7 pp 726ndash731 2014
STRs alleles in different populations including Spaniards [27]Fang Africans [28] and a Native American pool of Huastecos[29] and Tepehuas [30] from the central region of Mexicowho were considered as parental populations
25 Statistical Analyses Continuous variables were analyzedusing a 119905-test and were presented as mean plusmn standarddeviation (SD) For categorical variables a Chi-square testor Fischer exact test was applied and data was presented aspercentage
The Hardy Weinberg equilibrium was calculated in con-trols using StatCalc software (Epi Info 2005 v332 Centersof Disease Control and Prevention Atlanta GA USA)Multivariable linear regression models were carried out foradjustment of glucose for potential confounders like agegender BMI and tobacco In order to assess the genetic riskfactor for diabetes and obesity logistic regression analyseswere applied to estimate the OR for each polymorphismBecause the associations between the SNPs and the outcomeshave been previously reported it is unlikely to detect effectsdue to statistical fluctuations only Therefore correction bymultiple comparisons was not applied Associations wereconsidered statistically significant at a nominal 119875 valuele005 Haplotype analysis was performed using PLINK andHaploview softwareThe 119905-test Chi-square test Fischer exacttest and multivariable regressions were performed using thestatistical software Stata 120 (StataCorp LP College StationTX USA)
3 Results
31 Clinical and Anthropometrical Measures General char-acteristics of the study population are shown in Table 1 Themean of age BMI glucose HbA1c triglycerides LDL-C andsystolic blood pressure were significantly higher in subjectswith diabetes as compared with control group On the otherhand the HDL-C levels were found lower in diabetic subjects(119875 lt 0001) which together show some of the metabolicabnormalities associated with T2DM Taking into accountthat obesity frequency was found higher in the control group(119875 lt 00001) it was considered as a potential confounder inmultivariate analyses
32 Genotype Frequency in Diabetic and Obese Subjects Thedistribution of the Native American (NAM) the European(EUR) and the African (AFR) individual admixture pro-portions was comparable between the diabetic subjects andcontrols (NAM 119875 = 02727 EUR 119875 = 02579 and AFR 119875 =01917) The analysis did not include the individual ancestryproportions which were not available for all the subjects
Table 2 shows genotype and allelic frequency of the poly-morphisms studied Hardy Weinberg equilibrium (HWE)test showed no deviation inside the population There wasno association with diabetes and genotype frequency foundin any of the polymorphisms studied (119875 gt 005) Howevertaking into account that the polymorphisms studied havebeen associated with obesity the genotype frequencies wereanalyzed according to obesity (Table 3) Lower frequency ofthe TT genotype in obese people was observed (47 versus
Table 1 Clinical and anthropometric characteristics of the studygroups
77) which provides a significant protection against obesity(OR 054119875 = 0012) Amarginal association but not signifi-cant (119875 = 006) was foundwith rs2071749 polymorphismandobesity Therefore subanalyses were carried out according togenetic inheritance models and diabetes and obesity statusand stratification by gender
When CC + CT genotype of the rs7211 polymorphismwas compared with TT lower frequency of TT genotypeassociated with lower BMI (TT 276 plusmn 4 versus CC + CT 29plusmn 5 119875 = 0011) and higher HDL-C levels (TT 58 plusmn 13 plusmn 4versus CC +CT 49 plusmn 12119875 = 0022) in obese subjects withoutdiabetes was found The OR revealed that TT genotype is aprotective factor against obesity in nondiabetic individuals(Table 4) In themultivariable analysis genotype (as recessivemodel) was negatively associated with BMI as well as HDL-C levels in nondiabetic subjects (Table 5) However theseassociations were not found in diabetic or diabetic obesesubjects
After gender stratification CC genotype was higher inobese women compared with nonobese women (Table 4)TT genotype was also lower in obese women (TT frequencyin obese women = 512 versus nonobese women = 923119875 = 0028) but significance was achieved when multivariateanalysis and logistic regression were carried out includinggenotype as dominant model Results showed that carryingone copy of T allele decreases the risk of obesity in women(Table 4) However the association of BMI with genotype wasweak and explains just 048 of BMI variability (Table 5)
The rs2071749 polymorphism in the HMOX1 gene wassignificantly associated with obesity when it was analyzedunder a dominantmodel (Table 6) AA carriers showed lowerBMI than AG + GG carriers and had lower risk of obesity
4 Oxidative Medicine and Cellular Longevity
Table 2 Genotype frequencies of the polymorphisms studied in diabetic patients and controls
Genepolymorphism Genotypes alleles Diabetes Controls OR (95 CI) 119875 119875 of HWE
AA 119899 () 27 (43) 54 (55) 076 (05ndash12) 0259CI confidence interval HWE Hardy-Weinberg equilibrium HMOX1 heme oxygenase-1 NQO1 NAD(P)H quinone oxidoreductase 1 NRF2 Nuclear factor-erythroid 2- (NF-E2-) related factor 2 OR odds ratio and TXNIP thioredoxin interacting protein
Table 3 Genotype and allele frequencies of the polymorphisms studied in obese and nonobese subjects
Genepolymorphism Genotype Obesity No obesity OR (95 CI) 119875
TRXNIPrs7211
CC n () 350 (566) 523 (537) ReferenceCT n () 239 (387) 376 (386) 095 (07ndash12) 0627TT n () 29 (47) 75 (77) 056 (035ndash087) 0012
NQO1rs1800566
CC n () 212 (342) 331 (333) ReferenceCT n () 302 (488) 469 (47) 1 (08ndash125) 0963TT n () 106 (17) 196 (197) 084 (06ndash11) 0257
HMOX1rs2071749
AA n () 261 (40) 419 (457) ReferenceAG n () 306 (469) 378 (413) 13 (1ndash16) 0019GG n () 85 (131) 119 (13) 11 (08ndash15) 114
NRF2rs2364723
CC n () 194 (31) 317 (32) ReferenceCG n () 300 (48) 457 (46) 11 (085ndash135) 0551GG n () 131 (21) 210 (22) 098 (07ndash13) 0899
NRF2rs6721961
CC n () 390 (631) 635 (639) ReferenceCA n () 195 (316) 311 (313) 1 (08ndash13) 0853AA n () 33 (53) 48 (48) 11 (07ndash17) 0631
CI confidence interval HMOX1 heme oxygenase-1 NQO1 NAD(P)H quinone oxidoreductase 1 NRF2 Nuclear factor-erythroid 2- (NF-E2-) related factor2 OR odds ratio and TXNIP thioredoxin interacting protein
The association of the rs2071749 polymorphism persists withobesity after being adjusted by age gender HDL-C levelsLDL-C levels and triglycerides concentrations
The rs6721961 polymorphism of the Nrf2 gene was asso-ciated with diabetes in men but not in women after strati-fication by gender (Table 7) CC carriers had higher glucoselevels in comparison with CA + CC carriers when genotypewas compared as dominant model Thus the presence ofthe A allele represents a protective factor against diabetes inmen The pairwise linkage disequilibrium (LD) analysis ofthe rs6721961 and rs2364723 in NRF2 gene revealed a low
LD between them (1199032 = 031) Additionally the analysesof potential haplotype effects showed no association withdiabetes (119875 = 074) or obesity (119875 = 052)
4 Discussion
Oxidative stress is one of themajormetabolic factors that leadto the onset of chronic disease like insulin resistance hyper-tension metabolic syndrome prediabetes diabetes and itscomplications It has been recognized that the antioxidantsystem is abated in diabetes and obesity accompanied by an
Oxidative Medicine and Cellular Longevity 5
Table 4 Genotype frequency of the rs7211 polymorphism in subjects without diabetes and women
Obese Nonobese Crude OR (95 CI) 119875 Adjusteda OR (95 CI) 119875
CI confidence interval OR odds ratioaObesity in logistic regression was adjusted by age gender (except in women model) glucose triglycerides LDL-C and HDL-C levels
Table 5 Multiple linear regression of BMI as dependent variable innondiabetic subjects and women
Models also include age gender (in nondiabetic subjectsmodel) LDL-C andtriglycerides Significant variables were presented BMI body mass indexHDL-C high-density lipoprotein cholesterol
increased production of inflammatory cytokines A defect inNrf2 activation in many organs has been documented widelyin experimental models of insulin resistance and diabetesleading to decreased expression of its target genes [31ndash34]In this study it was found that the rs6721961 (minus617CA)polymorphism of Nrf2 gene was associated with diabetes inMexican mestizo men while the rs7211 polymorphism ofTXNIP gene and the rs2071749 polymorphism of HMOX1genewere associatedwith obesity Nevertheless the polymor-phisms rs1800566 (NQO1) and rs2364723 (Nrf2) were notfound to be associated with diabetes or obesity
Wang et al [35] did not found association between thers1800566 polymorphism in NQO1 gene and the risk ofT2DM in Chinese population On the other hand Kim[36] reported that there were no associations betweenthe rs1800566 polymorphism and BMI blood pressurelipid profile HbA1c postprandial glucose and homeostasismodel assessment-insulin resistance (HOMA-IR) Neverthe-lessMartınez-Hernandez et al [18] showed that theT allele ofthe rs1800566 polymorphism was associated with increasedtriglycerides levels and decreased HDL-C levels in Mexicanmestizo individuals with metabolic syndrome However inthis study this association was not found and we suggest thatthis difference is due to the fact that 57 and 47 of the
subjects recruited in our study were under medical treatmentwith fibrates and statins respectively and attend to clinicaldetection annually
The rs7211 has been poorly studied in diabetic and obesesubjects First van Greevenbroek et al [23] found thattriglycerides levels were higher in diabetic subjects with theT allele than the C allele carriers which was associatedwith higher glucose concentrations Subsequently Ferreiraet al [24] found that the rs7211 was associated in Braziliansubjects with diabetes and hypertension and T carriersshowed higher concentrations of blood glucose and systolicblood pressure Das et al [37] reported that in European-American or African-American subjects recruited in USAthe TXNIP gene expression was negatively correlated withobesity In this study the T allele was found as a protectionfactor against metabolic traits like BMI and HDL-C TheT allele carriers showed that lower BMI values and HDL-C concentrations in nondiabetic subjects and in women arestill associated with obesity after adjustment by confoundingfactors Some authors reported that this polymorphism canincreaseTXNIP expression [22] but this still remains unclearHowever this is the first report in which it was found that Tallele is a protective factor against obesity and we suggest thatTXNIP expression or function would be affected allowingTXN to exert its antioxidant action
The SNP rs2071746 (T-413A) and (GT)119899microsatellite
are polymorphisms in the promoter region of HMOX1 genewhich canmodulate its transcriptional activity and have beenassociated with various human diseases [19] Lin et al [20]showed that the (GT)
119899repeat in the HMOX1 promoter was
significantly associated with essential hypertension systolicblood pressure and diastolic blood pressure whereas theother two SNPs rs2071746 and rs2071749 were not asso-ciated Although the rs2071749 has been poorly studiedwith metabolic traits in this study it was found that AAcarriers showed lower BMI values which were associatedwith the risk of presenting obesity whereas GG carriersshowed higher BMI values This is the first report showingthe association of the rs2071749 polymorphism and obesityThis polymorphism is an intronic tag SNP and it has reportedthat it is in LD with the rs3761439 which is located in
6 Oxidative Medicine and Cellular Longevity
Table 6 Association of the rs2071749 polymorphism of the HMOX1 gene with obesity
AA 261 (40) 410 (46) 0026 289 plusmn 49 0027AG + GG 390 (60) 497 (54) 295 plusmn 53Crude OR (95 CI) 125 (102ndash154) 0026OR adjusteda (95 CI) 134 (106ndash17) 0013Beta coefficient1198772b 0063003 0023BMI values are presented as mean plusmn SD BMI body mass index CI confidence interval and OR odds ratioaObesity in logistic regression was adjusted by age gender glucose triglycerides and LDL-C and HDL-C levels Genotype was included as dominant modelin logistic and multivariate analysisbLinear regression of BMI as dependent variable was adjusted by age gender glucose triglycerides and LDL-C and HDL-C levels
Table 7 Association of the rs6721961 polymorphism of the Nrf2 gene with diabetes in men
Crude OR (95 CI) 062 (046ndash085) 0003OR adjusteda (95 CI) 056 (038ndash082) 0003Crude beta coefficient minus0078 0031Glucose values (mgsdotdLminus1) are presented as mean plusmn SD CI confidence interval OR odds ratioaDiabetes in logistic regression was adjusted by age triglycerides and LDL-C and HDL-C levels Genotype was included as dominant model in logistic andlinear regressionb119875 value when comparing each genotype
c119875 value in comparison of CC with CA + AA
the promoter region of the HMOX1 gene The consensussequence of a nuclear factor 120581B (NF-120581B) binding site toHMOX1 is altered by rs3761439 polymorphism that increasesthe risk of developing impaired lung function [38] Thissuggests that the mechanisms by which this polymorphismcould be involved in obesity may be secondary to increasedoxidative stress and inflammation The results in this workopen the gate to new investigations about the role of theHMOX1 gene in Mexican obese patients
NRF2 gene regulates the enzymes studied here ManySNPs have been identified in this gene The rs35652124 andrs6721961 SNPs are predicted to affect Nrf2 myeloid zincfinger 1 (MZF1) and antioxidant response elements- (ARE-) like promoter binding sites respectively These SNPs affectthe efficient binding of proteins such as Nrf2 to theMZF1 andARE-like promoter binding sites [39]
In metabolic diseases the rs6721961 polymorphism hasbeen associated with blood pressure in Japanese subjects [39]Wang et al [7] showed that the rs6721961 polymorphism inthe NRF2 gene was significantly associated with oxidativestress antioxidant status and risk of newly diagnosed T2DMas well as with impaired insulin secretory capacity andincreased insulin resistance in T2DM patients of a Chinesepopulation Individuals with the CC genotype had lowertotal antioxidant capacity glutathione levels and superoxidedismutase catalase and glutathione peroxidase activitiesas well as lower homeostasis model assessment of 120573-cellfunction index (HOMA-120573) in comparison with individualswith the CC genotypeThosewith theAA genotype also had a
higher malondialdehyde concentration andHOMA-IR indexvalues The frequency of allele A was significantly higher inT2DM subjects (294) Individuals with the AA genotypehad a significantly higher risk of developing T2DM relativeto thosewith theCCgenotype even after adjusting for knownT2DM risk factors However this investigation showed thatthe AA carriers had lower glucose concentrations and theOR revealed that A carriers had lower risk of developingdiabetes in men after stratification by gender We had thelimitation that Nrf2 gene expression was not determined inthese patients and it is essential to elucidate the mechanismsby which the rs6721961 polymorphism can exert its protectiveeffect in our population Larger sample size could supportthis
We know that this research has some limitations Thegene expressions and activities were not determined and justcandidate genes were included Dietary information was notavailable in all patients However this study opens the gate tonew researches about the role of HMOX1 TXNIP and Nrf2in obesity diabetes and worse metabolic traits
5 Conclusions
This study shows that the rs7211 polymorphism in the TXNIPgene and the rs2071749 of the HMOX1 gene are associatedwith obesity in Mexican mestizo people In this sensers2071749 increases the risk of having obesity and the rs7211polymorphism may be a protective factor to develop obesityand to have lower concentrations of HDL-C in Mexican
Oxidative Medicine and Cellular Longevity 7
mestizo women In addition rs6721961 gen polymorphismin Nrf2 was negatively associated with diabetes in men Allof these results open the doors for new research taking intoaccount the effect onmetabolic traits andmay be useful toolsto design new therapeutic strategies in obesity and diabetestype 2
Competing Interests
The authors declare that they have no competing interests
Acknowledgments
The authors would like to acknowledge the Medical FamilyClinics from ISSSTE Ignacio Chavez Del Valle Xochimilcoand Fuentes Brotantes This work was financially supportedby CONACyT-Mexico (Grant no SALUD-2013-01-201519)
[2] R H Eckel S E Kahn E Ferrannini et al ldquoObesity andtype 2 diabetes what can be unified and what needs to beindividualizedrdquo Diabetes Care vol 34 no 6 pp 1424ndash14302011
[3] S Tyrovolas A Koyanagi NGarin et al ldquoDiabetesmellitus andits association with central obesity and disability among olderadults a global perspectiverdquo Experimental Gerontology vol 64pp 70ndash77 2015
[4] M Serrano-Rios ldquoRelationship between obesity and theincreased risk of major complications in non-insulin-depend-ent diabetesmellitusrdquo European Journal of Clinical Investigationvol 28 supplement 2 pp 14ndash18 1998
[5] S-I Yamagishi S Maeda T Matsui S Ueda K Fukami andS Okuda ldquoRole of advanced glycation end products (AGEs)and oxidative stress in vascular complications in diabetesrdquoBiochimica et Biophysica ActamdashGeneral Subjects vol 1820 no5 pp 663ndash671 2012
[6] Y-J Surh J K Kundu and H-K Na ldquoNrf2 as a master redoxswitch in turning on the cellular signaling involved in theinduction of cytoprotective genes by some chemopreventivephytochemicalsrdquo Planta Medica vol 74 no 13 pp 1526ndash15392008
[7] X Wang H Chen J Liu et al ldquoAssociation between the NF-E2related factor 2 gene polymorphism and oxidative stress anti-oxidative status and newly-diagnosed type 2 diabetes mellitusin a Chinese populationrdquo International Journal of MolecularSciences vol 16 no 7 pp 16483ndash16496 2015
[8] A S Jimenez-Osorio A Picazo S Gonzalez-Reyes D Barrera-Oviedo M E Rodrıguez-Arellano and J Pedraza-ChaverrildquoNrf2 and redox status in prediabetic and diabetic patientsrdquoInternational Journal of Molecular Sciences vol 15 no 11 pp20290ndash20305 2014
[9] J Pi L Leung P Xue et al ldquoDeficiency in the nuclear factorE2-related factor-2 transcription factor results in impairedadipogenesis and protects against diet-induced obesityrdquo TheJournal of Biological Chemistry vol 285 no 12 pp 9292ndash93002010
[10] H-Y Cho ldquoGenomic structure and variation of nuclear factor(erythroid-derived 2)-like 2rdquo Oxidative Medicine and CellularLongevity vol 2013 Article ID 286524 24 pages 2013
[11] Y Shimoyama Y Mitsuda N Hamajima and T Niwa ldquoPoly-morphisms of Nrf2 an antioxidative gene are associated withblood pressure in Japaneserdquo Nagoya Journal of Medical Sciencevol 76 no 1-2 pp 113ndash120 2014
[12] S M Figarska J M Vonk and H M Boezen ldquoNFE2L2polymorphisms mortality and metabolism in the generalpopulationrdquo Physiological Genomics vol 46 no 12 pp 411ndash4172014
[13] D Ross and D Siegel ldquoNAD(P)Hquinone oxidoreductase1 (NQO1 DT-diaphorase) functions and pharmacogeneticsrdquoMethods in Enzymology vol 382 pp 115ndash144 2004
[14] J-E Chung B C Chang K E Lee J H Kim and H S GwakldquoEffects of NAD(P)Hquinone oxidoreductase 1 polymorphismson stable warfarin doses in Korean patients with mechanicalcardiac valvesrdquo European Journal of Clinical Pharmacology vol71 no 10 pp 1229ndash1236 2015
[15] H-Y Shyu C-S Fong Y-P Fu et al ldquoGenotype polymor-phisms of GGCX NQO1 and VKORC1 genes associated withrisk susceptibility in patients with large-artery atheroscleroticstrokerdquo Clinica Chimica Acta vol 411 no 11-12 pp 840ndash8452010
[16] S J Han E S Kang H J Kim et al ldquoThe C609T variant ofNQO1 is associated with carotid artery plaques in patients withtype 2 diabetesrdquoMolecular Genetics andMetabolism vol 97 no1 pp 85ndash90 2009
[17] T Ramprasath P S Murugan E Kalaiarasan P GomathiA Rathinavel and G S Selvam ldquoGenetic association ofGlutathione peroxidase-1 (GPx-1) and NAD(P)Hquinone oxi-doreductase 1(NQO1) variants and their association of CAD inpatients with type-2 diabetesrdquoMolecular and Cellular Biochem-istry vol 361 no 1-2 pp 143ndash150 2012
[18] A Martınez-Hernandez E J Cordova O Rosillo-Salazar etal ldquoAssociation of HMOX1 and NQO1 polymorphisms withmetabolic syndrome componentsrdquo PLoS ONE vol 10 no 5Article ID e0123313 2015
[19] E Y Lee Y H Lee S H Kim et al ldquoAssociation between hemeoxygenase-1 promoter polymorphisms and the development ofalbuminuria in type 2 diabetes a case-control studyrdquoMedicinevol 94 no 43 article e1825 2015
[20] R Lin W Fu W Zhou et al ldquoAssociation of heme oxygenase-1 gene polymorphisms with essential hypertension and bloodpressure in the Chinese Han populationrdquo Genetic Testing andMolecular Biomarkers vol 15 no 1-2 pp 23ndash28 2011
[21] E Junn S H Han J Y Im et al ldquoVitamin D3 up-regulated pro-tein 1 mediates oxidative stress via suppressing the thioredoxinfunctionrdquoThe Journal of Immunology vol 164 no 12 pp 6287ndash6295 2000
[22] X He and QMa ldquoRedox regulation by nuclear factor erythroid2-related factor 2 gatekeeping for the basal and diabetes-induced expression of thioredoxin-interacting proteinrdquo Molec-ular Pharmacology vol 82 no 5 pp 887ndash897 2012
[23] M M J van Greevenbroek V M M-J Vermeulen E J MFeskens et al ldquoGenetic variation in thioredoxin interactingprotein (TXNIP) is associated with hypertriglyceridaemia andblood pressure in diabetes mellitusrdquo Diabetic Medicine vol 24no 5 pp 498ndash504 2007
[24] N E Ferreira S Omae A Pereira et al ldquoThioredoxin inter-acting protein genetic variation is associated with diabetes and
8 Oxidative Medicine and Cellular Longevity
hypertension in the Brazilian general populationrdquoAtherosclero-sis vol 221 no 1 pp 131ndash136 2012
[25] J Grimberg S Nawoschik L Belluscio R McKee A Turckand A Eisenberg ldquoA simple and efficient non-organic proce-dure for the isolation of genomic DNA from bloodrdquo NucleicAcids Research vol 17 no 20 p 8390 1989
[26] J Zuniga N Yu R Barquera et al ldquoHLA class I and class IIconserved extended haplotypes and their fragments or blocksin mexicans implications for the study of genetic diversityin admixed populationsrdquo PLoS ONE vol 8 no 9 Article IDe74442 2013
[27] P Sanz V Prieto I Flores Y Torres M Lopez-Soto andM J Farfan ldquoPopulation data of 13 STRS in southern Spain(Andalusia)rdquo Forensic Science International vol 119 no 1 pp113ndash115 2001
[28] P Calzada I Suarez S Garcıa et al ldquoThe Fang populationof Equatorial Guinea characterised by 15 STR-PCR polymor-phismsrdquo International Journal of Legal Medicine vol 119 no 2pp 107ndash110 2005
[29] C Barrot C Sanchez M Ortega et al ldquoCharacterisation ofthree Amerindian populations from Hidalgo State (Mexico)by 15 STR-PCR polymorphismsrdquo International Journal of LegalMedicine vol 119 no 2 pp 111ndash115 2005
[30] A Gonzalez-Martın A Gorostiza H Rangel-Villalobos et alldquoAnalyzing the genetic structure of the Tepehua in relation toother neighbouring Mesoamerican populations A study basedon allele frequencies of STR markersrdquo American Journal ofHuman Biology vol 20 no 5 pp 605ndash613 2008
[31] Y Tan T Ichikawa J Li et al ldquoDiabetic downregulation of Nrf2activity via ERK contributes to oxidative stress-induced insulinresistance in cardiac cells in vitro and in vivordquoDiabetes vol 60no 2 pp 625ndash633 2011
[32] H-A Seo and I-K Lee ldquoThe role of NRF2 adipocyte differen-tiation obesity and insulin resistancerdquo Oxidative Medicine andCellular Longevity vol 2013 Article ID 184598 7 pages 2013
[33] J Xu A C Donepudi V R More et al ldquoDeficiency in Nrf2transcription factor decreases adipose tissue mass and hepaticlipid accumulation in leptin-deficientmicerdquoObesity vol 23 no2 pp 335ndash344 2015
[34] A Uruno Y Yagishita and M Yamamoto ldquoThe Keap1-Nrf2system and diabetes mellitusrdquo Archives of Biochemistry andBiophysics vol 566 pp 76ndash84 2015
[35] G Wang L Zhang and Q Li ldquoGenetic polymorphisms ofGSTT1 GSTM1 and NQO1 genes and diabetes mellitus riskin Chinese populationrdquo Biochemical and Biophysical ResearchCommunications vol 341 no 2 pp 310ndash313 2006
[36] D Kim ldquoAn association between 609 CrarrT Polymorphism inNAD(P)Hquinone oxidoreductase 1 (NQO1) gene and bloodglucose levels in Korean populationrdquo Korean Diabetes Journalvol 33 no 1 pp 24ndash30 2009
[37] S K Das N K Sharma S J Hasstedt et al ldquoAn integra-tive genomics approach identifies activation of thioredoxinthioredoxin reductase-1-mediated oxidative stress defense path-way and inhibition of angiogenesis in obese nondiabetic humansubjectsrdquo The Journal of Clinical Endocrinology amp Metabolismvol 96 no 8 pp E1308ndashE1313 2011
[38] G Tanaka F Aminuddin L Akhabir et al ldquoEffect of hemeoxygenase-1 polymorphisms on lung function and gene expres-sionrdquo BMCMedical Genetics vol 12 article 117 2011
[39] Y Shimoyama Y Mitsuda Y Tsuruta N Hamajima andT Niwa ldquoPolymorphism of Nrf2 an antioxidative gene is
associated with blood pressure and cardiovascular mortalityin hemodialysis patientsrdquo International Journal of MedicalSciences vol 11 no 7 pp 726ndash731 2014
AA 119899 () 27 (43) 54 (55) 076 (05ndash12) 0259CI confidence interval HWE Hardy-Weinberg equilibrium HMOX1 heme oxygenase-1 NQO1 NAD(P)H quinone oxidoreductase 1 NRF2 Nuclear factor-erythroid 2- (NF-E2-) related factor 2 OR odds ratio and TXNIP thioredoxin interacting protein
Table 3 Genotype and allele frequencies of the polymorphisms studied in obese and nonobese subjects
Genepolymorphism Genotype Obesity No obesity OR (95 CI) 119875
TRXNIPrs7211
CC n () 350 (566) 523 (537) ReferenceCT n () 239 (387) 376 (386) 095 (07ndash12) 0627TT n () 29 (47) 75 (77) 056 (035ndash087) 0012
NQO1rs1800566
CC n () 212 (342) 331 (333) ReferenceCT n () 302 (488) 469 (47) 1 (08ndash125) 0963TT n () 106 (17) 196 (197) 084 (06ndash11) 0257
HMOX1rs2071749
AA n () 261 (40) 419 (457) ReferenceAG n () 306 (469) 378 (413) 13 (1ndash16) 0019GG n () 85 (131) 119 (13) 11 (08ndash15) 114
NRF2rs2364723
CC n () 194 (31) 317 (32) ReferenceCG n () 300 (48) 457 (46) 11 (085ndash135) 0551GG n () 131 (21) 210 (22) 098 (07ndash13) 0899
NRF2rs6721961
CC n () 390 (631) 635 (639) ReferenceCA n () 195 (316) 311 (313) 1 (08ndash13) 0853AA n () 33 (53) 48 (48) 11 (07ndash17) 0631
CI confidence interval HMOX1 heme oxygenase-1 NQO1 NAD(P)H quinone oxidoreductase 1 NRF2 Nuclear factor-erythroid 2- (NF-E2-) related factor2 OR odds ratio and TXNIP thioredoxin interacting protein
The association of the rs2071749 polymorphism persists withobesity after being adjusted by age gender HDL-C levelsLDL-C levels and triglycerides concentrations
The rs6721961 polymorphism of the Nrf2 gene was asso-ciated with diabetes in men but not in women after strati-fication by gender (Table 7) CC carriers had higher glucoselevels in comparison with CA + CC carriers when genotypewas compared as dominant model Thus the presence ofthe A allele represents a protective factor against diabetes inmen The pairwise linkage disequilibrium (LD) analysis ofthe rs6721961 and rs2364723 in NRF2 gene revealed a low
LD between them (1199032 = 031) Additionally the analysesof potential haplotype effects showed no association withdiabetes (119875 = 074) or obesity (119875 = 052)
4 Discussion
Oxidative stress is one of themajormetabolic factors that leadto the onset of chronic disease like insulin resistance hyper-tension metabolic syndrome prediabetes diabetes and itscomplications It has been recognized that the antioxidantsystem is abated in diabetes and obesity accompanied by an
Oxidative Medicine and Cellular Longevity 5
Table 4 Genotype frequency of the rs7211 polymorphism in subjects without diabetes and women
Obese Nonobese Crude OR (95 CI) 119875 Adjusteda OR (95 CI) 119875
CI confidence interval OR odds ratioaObesity in logistic regression was adjusted by age gender (except in women model) glucose triglycerides LDL-C and HDL-C levels
Table 5 Multiple linear regression of BMI as dependent variable innondiabetic subjects and women
Models also include age gender (in nondiabetic subjectsmodel) LDL-C andtriglycerides Significant variables were presented BMI body mass indexHDL-C high-density lipoprotein cholesterol
increased production of inflammatory cytokines A defect inNrf2 activation in many organs has been documented widelyin experimental models of insulin resistance and diabetesleading to decreased expression of its target genes [31ndash34]In this study it was found that the rs6721961 (minus617CA)polymorphism of Nrf2 gene was associated with diabetes inMexican mestizo men while the rs7211 polymorphism ofTXNIP gene and the rs2071749 polymorphism of HMOX1genewere associatedwith obesity Nevertheless the polymor-phisms rs1800566 (NQO1) and rs2364723 (Nrf2) were notfound to be associated with diabetes or obesity
Wang et al [35] did not found association between thers1800566 polymorphism in NQO1 gene and the risk ofT2DM in Chinese population On the other hand Kim[36] reported that there were no associations betweenthe rs1800566 polymorphism and BMI blood pressurelipid profile HbA1c postprandial glucose and homeostasismodel assessment-insulin resistance (HOMA-IR) Neverthe-lessMartınez-Hernandez et al [18] showed that theT allele ofthe rs1800566 polymorphism was associated with increasedtriglycerides levels and decreased HDL-C levels in Mexicanmestizo individuals with metabolic syndrome However inthis study this association was not found and we suggest thatthis difference is due to the fact that 57 and 47 of the
subjects recruited in our study were under medical treatmentwith fibrates and statins respectively and attend to clinicaldetection annually
The rs7211 has been poorly studied in diabetic and obesesubjects First van Greevenbroek et al [23] found thattriglycerides levels were higher in diabetic subjects with theT allele than the C allele carriers which was associatedwith higher glucose concentrations Subsequently Ferreiraet al [24] found that the rs7211 was associated in Braziliansubjects with diabetes and hypertension and T carriersshowed higher concentrations of blood glucose and systolicblood pressure Das et al [37] reported that in European-American or African-American subjects recruited in USAthe TXNIP gene expression was negatively correlated withobesity In this study the T allele was found as a protectionfactor against metabolic traits like BMI and HDL-C TheT allele carriers showed that lower BMI values and HDL-C concentrations in nondiabetic subjects and in women arestill associated with obesity after adjustment by confoundingfactors Some authors reported that this polymorphism canincreaseTXNIP expression [22] but this still remains unclearHowever this is the first report in which it was found that Tallele is a protective factor against obesity and we suggest thatTXNIP expression or function would be affected allowingTXN to exert its antioxidant action
The SNP rs2071746 (T-413A) and (GT)119899microsatellite
are polymorphisms in the promoter region of HMOX1 genewhich canmodulate its transcriptional activity and have beenassociated with various human diseases [19] Lin et al [20]showed that the (GT)
119899repeat in the HMOX1 promoter was
significantly associated with essential hypertension systolicblood pressure and diastolic blood pressure whereas theother two SNPs rs2071746 and rs2071749 were not asso-ciated Although the rs2071749 has been poorly studiedwith metabolic traits in this study it was found that AAcarriers showed lower BMI values which were associatedwith the risk of presenting obesity whereas GG carriersshowed higher BMI values This is the first report showingthe association of the rs2071749 polymorphism and obesityThis polymorphism is an intronic tag SNP and it has reportedthat it is in LD with the rs3761439 which is located in
6 Oxidative Medicine and Cellular Longevity
Table 6 Association of the rs2071749 polymorphism of the HMOX1 gene with obesity
AA 261 (40) 410 (46) 0026 289 plusmn 49 0027AG + GG 390 (60) 497 (54) 295 plusmn 53Crude OR (95 CI) 125 (102ndash154) 0026OR adjusteda (95 CI) 134 (106ndash17) 0013Beta coefficient1198772b 0063003 0023BMI values are presented as mean plusmn SD BMI body mass index CI confidence interval and OR odds ratioaObesity in logistic regression was adjusted by age gender glucose triglycerides and LDL-C and HDL-C levels Genotype was included as dominant modelin logistic and multivariate analysisbLinear regression of BMI as dependent variable was adjusted by age gender glucose triglycerides and LDL-C and HDL-C levels
Table 7 Association of the rs6721961 polymorphism of the Nrf2 gene with diabetes in men
Crude OR (95 CI) 062 (046ndash085) 0003OR adjusteda (95 CI) 056 (038ndash082) 0003Crude beta coefficient minus0078 0031Glucose values (mgsdotdLminus1) are presented as mean plusmn SD CI confidence interval OR odds ratioaDiabetes in logistic regression was adjusted by age triglycerides and LDL-C and HDL-C levels Genotype was included as dominant model in logistic andlinear regressionb119875 value when comparing each genotype
c119875 value in comparison of CC with CA + AA
the promoter region of the HMOX1 gene The consensussequence of a nuclear factor 120581B (NF-120581B) binding site toHMOX1 is altered by rs3761439 polymorphism that increasesthe risk of developing impaired lung function [38] Thissuggests that the mechanisms by which this polymorphismcould be involved in obesity may be secondary to increasedoxidative stress and inflammation The results in this workopen the gate to new investigations about the role of theHMOX1 gene in Mexican obese patients
NRF2 gene regulates the enzymes studied here ManySNPs have been identified in this gene The rs35652124 andrs6721961 SNPs are predicted to affect Nrf2 myeloid zincfinger 1 (MZF1) and antioxidant response elements- (ARE-) like promoter binding sites respectively These SNPs affectthe efficient binding of proteins such as Nrf2 to theMZF1 andARE-like promoter binding sites [39]
In metabolic diseases the rs6721961 polymorphism hasbeen associated with blood pressure in Japanese subjects [39]Wang et al [7] showed that the rs6721961 polymorphism inthe NRF2 gene was significantly associated with oxidativestress antioxidant status and risk of newly diagnosed T2DMas well as with impaired insulin secretory capacity andincreased insulin resistance in T2DM patients of a Chinesepopulation Individuals with the CC genotype had lowertotal antioxidant capacity glutathione levels and superoxidedismutase catalase and glutathione peroxidase activitiesas well as lower homeostasis model assessment of 120573-cellfunction index (HOMA-120573) in comparison with individualswith the CC genotypeThosewith theAA genotype also had a
higher malondialdehyde concentration andHOMA-IR indexvalues The frequency of allele A was significantly higher inT2DM subjects (294) Individuals with the AA genotypehad a significantly higher risk of developing T2DM relativeto thosewith theCCgenotype even after adjusting for knownT2DM risk factors However this investigation showed thatthe AA carriers had lower glucose concentrations and theOR revealed that A carriers had lower risk of developingdiabetes in men after stratification by gender We had thelimitation that Nrf2 gene expression was not determined inthese patients and it is essential to elucidate the mechanismsby which the rs6721961 polymorphism can exert its protectiveeffect in our population Larger sample size could supportthis
We know that this research has some limitations Thegene expressions and activities were not determined and justcandidate genes were included Dietary information was notavailable in all patients However this study opens the gate tonew researches about the role of HMOX1 TXNIP and Nrf2in obesity diabetes and worse metabolic traits
5 Conclusions
This study shows that the rs7211 polymorphism in the TXNIPgene and the rs2071749 of the HMOX1 gene are associatedwith obesity in Mexican mestizo people In this sensers2071749 increases the risk of having obesity and the rs7211polymorphism may be a protective factor to develop obesityand to have lower concentrations of HDL-C in Mexican
Oxidative Medicine and Cellular Longevity 7
mestizo women In addition rs6721961 gen polymorphismin Nrf2 was negatively associated with diabetes in men Allof these results open the doors for new research taking intoaccount the effect onmetabolic traits andmay be useful toolsto design new therapeutic strategies in obesity and diabetestype 2
Competing Interests
The authors declare that they have no competing interests
Acknowledgments
The authors would like to acknowledge the Medical FamilyClinics from ISSSTE Ignacio Chavez Del Valle Xochimilcoand Fuentes Brotantes This work was financially supportedby CONACyT-Mexico (Grant no SALUD-2013-01-201519)
[2] R H Eckel S E Kahn E Ferrannini et al ldquoObesity andtype 2 diabetes what can be unified and what needs to beindividualizedrdquo Diabetes Care vol 34 no 6 pp 1424ndash14302011
[3] S Tyrovolas A Koyanagi NGarin et al ldquoDiabetesmellitus andits association with central obesity and disability among olderadults a global perspectiverdquo Experimental Gerontology vol 64pp 70ndash77 2015
[4] M Serrano-Rios ldquoRelationship between obesity and theincreased risk of major complications in non-insulin-depend-ent diabetesmellitusrdquo European Journal of Clinical Investigationvol 28 supplement 2 pp 14ndash18 1998
[5] S-I Yamagishi S Maeda T Matsui S Ueda K Fukami andS Okuda ldquoRole of advanced glycation end products (AGEs)and oxidative stress in vascular complications in diabetesrdquoBiochimica et Biophysica ActamdashGeneral Subjects vol 1820 no5 pp 663ndash671 2012
[6] Y-J Surh J K Kundu and H-K Na ldquoNrf2 as a master redoxswitch in turning on the cellular signaling involved in theinduction of cytoprotective genes by some chemopreventivephytochemicalsrdquo Planta Medica vol 74 no 13 pp 1526ndash15392008
[7] X Wang H Chen J Liu et al ldquoAssociation between the NF-E2related factor 2 gene polymorphism and oxidative stress anti-oxidative status and newly-diagnosed type 2 diabetes mellitusin a Chinese populationrdquo International Journal of MolecularSciences vol 16 no 7 pp 16483ndash16496 2015
[8] A S Jimenez-Osorio A Picazo S Gonzalez-Reyes D Barrera-Oviedo M E Rodrıguez-Arellano and J Pedraza-ChaverrildquoNrf2 and redox status in prediabetic and diabetic patientsrdquoInternational Journal of Molecular Sciences vol 15 no 11 pp20290ndash20305 2014
[9] J Pi L Leung P Xue et al ldquoDeficiency in the nuclear factorE2-related factor-2 transcription factor results in impairedadipogenesis and protects against diet-induced obesityrdquo TheJournal of Biological Chemistry vol 285 no 12 pp 9292ndash93002010
[10] H-Y Cho ldquoGenomic structure and variation of nuclear factor(erythroid-derived 2)-like 2rdquo Oxidative Medicine and CellularLongevity vol 2013 Article ID 286524 24 pages 2013
[11] Y Shimoyama Y Mitsuda N Hamajima and T Niwa ldquoPoly-morphisms of Nrf2 an antioxidative gene are associated withblood pressure in Japaneserdquo Nagoya Journal of Medical Sciencevol 76 no 1-2 pp 113ndash120 2014
[12] S M Figarska J M Vonk and H M Boezen ldquoNFE2L2polymorphisms mortality and metabolism in the generalpopulationrdquo Physiological Genomics vol 46 no 12 pp 411ndash4172014
[13] D Ross and D Siegel ldquoNAD(P)Hquinone oxidoreductase1 (NQO1 DT-diaphorase) functions and pharmacogeneticsrdquoMethods in Enzymology vol 382 pp 115ndash144 2004
[14] J-E Chung B C Chang K E Lee J H Kim and H S GwakldquoEffects of NAD(P)Hquinone oxidoreductase 1 polymorphismson stable warfarin doses in Korean patients with mechanicalcardiac valvesrdquo European Journal of Clinical Pharmacology vol71 no 10 pp 1229ndash1236 2015
[15] H-Y Shyu C-S Fong Y-P Fu et al ldquoGenotype polymor-phisms of GGCX NQO1 and VKORC1 genes associated withrisk susceptibility in patients with large-artery atheroscleroticstrokerdquo Clinica Chimica Acta vol 411 no 11-12 pp 840ndash8452010
[16] S J Han E S Kang H J Kim et al ldquoThe C609T variant ofNQO1 is associated with carotid artery plaques in patients withtype 2 diabetesrdquoMolecular Genetics andMetabolism vol 97 no1 pp 85ndash90 2009
[17] T Ramprasath P S Murugan E Kalaiarasan P GomathiA Rathinavel and G S Selvam ldquoGenetic association ofGlutathione peroxidase-1 (GPx-1) and NAD(P)Hquinone oxi-doreductase 1(NQO1) variants and their association of CAD inpatients with type-2 diabetesrdquoMolecular and Cellular Biochem-istry vol 361 no 1-2 pp 143ndash150 2012
[18] A Martınez-Hernandez E J Cordova O Rosillo-Salazar etal ldquoAssociation of HMOX1 and NQO1 polymorphisms withmetabolic syndrome componentsrdquo PLoS ONE vol 10 no 5Article ID e0123313 2015
[19] E Y Lee Y H Lee S H Kim et al ldquoAssociation between hemeoxygenase-1 promoter polymorphisms and the development ofalbuminuria in type 2 diabetes a case-control studyrdquoMedicinevol 94 no 43 article e1825 2015
[20] R Lin W Fu W Zhou et al ldquoAssociation of heme oxygenase-1 gene polymorphisms with essential hypertension and bloodpressure in the Chinese Han populationrdquo Genetic Testing andMolecular Biomarkers vol 15 no 1-2 pp 23ndash28 2011
[21] E Junn S H Han J Y Im et al ldquoVitamin D3 up-regulated pro-tein 1 mediates oxidative stress via suppressing the thioredoxinfunctionrdquoThe Journal of Immunology vol 164 no 12 pp 6287ndash6295 2000
[22] X He and QMa ldquoRedox regulation by nuclear factor erythroid2-related factor 2 gatekeeping for the basal and diabetes-induced expression of thioredoxin-interacting proteinrdquo Molec-ular Pharmacology vol 82 no 5 pp 887ndash897 2012
[23] M M J van Greevenbroek V M M-J Vermeulen E J MFeskens et al ldquoGenetic variation in thioredoxin interactingprotein (TXNIP) is associated with hypertriglyceridaemia andblood pressure in diabetes mellitusrdquo Diabetic Medicine vol 24no 5 pp 498ndash504 2007
[24] N E Ferreira S Omae A Pereira et al ldquoThioredoxin inter-acting protein genetic variation is associated with diabetes and
8 Oxidative Medicine and Cellular Longevity
hypertension in the Brazilian general populationrdquoAtherosclero-sis vol 221 no 1 pp 131ndash136 2012
[25] J Grimberg S Nawoschik L Belluscio R McKee A Turckand A Eisenberg ldquoA simple and efficient non-organic proce-dure for the isolation of genomic DNA from bloodrdquo NucleicAcids Research vol 17 no 20 p 8390 1989
[26] J Zuniga N Yu R Barquera et al ldquoHLA class I and class IIconserved extended haplotypes and their fragments or blocksin mexicans implications for the study of genetic diversityin admixed populationsrdquo PLoS ONE vol 8 no 9 Article IDe74442 2013
[27] P Sanz V Prieto I Flores Y Torres M Lopez-Soto andM J Farfan ldquoPopulation data of 13 STRS in southern Spain(Andalusia)rdquo Forensic Science International vol 119 no 1 pp113ndash115 2001
[28] P Calzada I Suarez S Garcıa et al ldquoThe Fang populationof Equatorial Guinea characterised by 15 STR-PCR polymor-phismsrdquo International Journal of Legal Medicine vol 119 no 2pp 107ndash110 2005
[29] C Barrot C Sanchez M Ortega et al ldquoCharacterisation ofthree Amerindian populations from Hidalgo State (Mexico)by 15 STR-PCR polymorphismsrdquo International Journal of LegalMedicine vol 119 no 2 pp 111ndash115 2005
[30] A Gonzalez-Martın A Gorostiza H Rangel-Villalobos et alldquoAnalyzing the genetic structure of the Tepehua in relation toother neighbouring Mesoamerican populations A study basedon allele frequencies of STR markersrdquo American Journal ofHuman Biology vol 20 no 5 pp 605ndash613 2008
[31] Y Tan T Ichikawa J Li et al ldquoDiabetic downregulation of Nrf2activity via ERK contributes to oxidative stress-induced insulinresistance in cardiac cells in vitro and in vivordquoDiabetes vol 60no 2 pp 625ndash633 2011
[32] H-A Seo and I-K Lee ldquoThe role of NRF2 adipocyte differen-tiation obesity and insulin resistancerdquo Oxidative Medicine andCellular Longevity vol 2013 Article ID 184598 7 pages 2013
[33] J Xu A C Donepudi V R More et al ldquoDeficiency in Nrf2transcription factor decreases adipose tissue mass and hepaticlipid accumulation in leptin-deficientmicerdquoObesity vol 23 no2 pp 335ndash344 2015
[34] A Uruno Y Yagishita and M Yamamoto ldquoThe Keap1-Nrf2system and diabetes mellitusrdquo Archives of Biochemistry andBiophysics vol 566 pp 76ndash84 2015
[35] G Wang L Zhang and Q Li ldquoGenetic polymorphisms ofGSTT1 GSTM1 and NQO1 genes and diabetes mellitus riskin Chinese populationrdquo Biochemical and Biophysical ResearchCommunications vol 341 no 2 pp 310ndash313 2006
[36] D Kim ldquoAn association between 609 CrarrT Polymorphism inNAD(P)Hquinone oxidoreductase 1 (NQO1) gene and bloodglucose levels in Korean populationrdquo Korean Diabetes Journalvol 33 no 1 pp 24ndash30 2009
[37] S K Das N K Sharma S J Hasstedt et al ldquoAn integra-tive genomics approach identifies activation of thioredoxinthioredoxin reductase-1-mediated oxidative stress defense path-way and inhibition of angiogenesis in obese nondiabetic humansubjectsrdquo The Journal of Clinical Endocrinology amp Metabolismvol 96 no 8 pp E1308ndashE1313 2011
[38] G Tanaka F Aminuddin L Akhabir et al ldquoEffect of hemeoxygenase-1 polymorphisms on lung function and gene expres-sionrdquo BMCMedical Genetics vol 12 article 117 2011
[39] Y Shimoyama Y Mitsuda Y Tsuruta N Hamajima andT Niwa ldquoPolymorphism of Nrf2 an antioxidative gene is
associated with blood pressure and cardiovascular mortalityin hemodialysis patientsrdquo International Journal of MedicalSciences vol 11 no 7 pp 726ndash731 2014
CI confidence interval OR odds ratioaObesity in logistic regression was adjusted by age gender (except in women model) glucose triglycerides LDL-C and HDL-C levels
Table 5 Multiple linear regression of BMI as dependent variable innondiabetic subjects and women
Models also include age gender (in nondiabetic subjectsmodel) LDL-C andtriglycerides Significant variables were presented BMI body mass indexHDL-C high-density lipoprotein cholesterol
increased production of inflammatory cytokines A defect inNrf2 activation in many organs has been documented widelyin experimental models of insulin resistance and diabetesleading to decreased expression of its target genes [31ndash34]In this study it was found that the rs6721961 (minus617CA)polymorphism of Nrf2 gene was associated with diabetes inMexican mestizo men while the rs7211 polymorphism ofTXNIP gene and the rs2071749 polymorphism of HMOX1genewere associatedwith obesity Nevertheless the polymor-phisms rs1800566 (NQO1) and rs2364723 (Nrf2) were notfound to be associated with diabetes or obesity
Wang et al [35] did not found association between thers1800566 polymorphism in NQO1 gene and the risk ofT2DM in Chinese population On the other hand Kim[36] reported that there were no associations betweenthe rs1800566 polymorphism and BMI blood pressurelipid profile HbA1c postprandial glucose and homeostasismodel assessment-insulin resistance (HOMA-IR) Neverthe-lessMartınez-Hernandez et al [18] showed that theT allele ofthe rs1800566 polymorphism was associated with increasedtriglycerides levels and decreased HDL-C levels in Mexicanmestizo individuals with metabolic syndrome However inthis study this association was not found and we suggest thatthis difference is due to the fact that 57 and 47 of the
subjects recruited in our study were under medical treatmentwith fibrates and statins respectively and attend to clinicaldetection annually
The rs7211 has been poorly studied in diabetic and obesesubjects First van Greevenbroek et al [23] found thattriglycerides levels were higher in diabetic subjects with theT allele than the C allele carriers which was associatedwith higher glucose concentrations Subsequently Ferreiraet al [24] found that the rs7211 was associated in Braziliansubjects with diabetes and hypertension and T carriersshowed higher concentrations of blood glucose and systolicblood pressure Das et al [37] reported that in European-American or African-American subjects recruited in USAthe TXNIP gene expression was negatively correlated withobesity In this study the T allele was found as a protectionfactor against metabolic traits like BMI and HDL-C TheT allele carriers showed that lower BMI values and HDL-C concentrations in nondiabetic subjects and in women arestill associated with obesity after adjustment by confoundingfactors Some authors reported that this polymorphism canincreaseTXNIP expression [22] but this still remains unclearHowever this is the first report in which it was found that Tallele is a protective factor against obesity and we suggest thatTXNIP expression or function would be affected allowingTXN to exert its antioxidant action
The SNP rs2071746 (T-413A) and (GT)119899microsatellite
are polymorphisms in the promoter region of HMOX1 genewhich canmodulate its transcriptional activity and have beenassociated with various human diseases [19] Lin et al [20]showed that the (GT)
119899repeat in the HMOX1 promoter was
significantly associated with essential hypertension systolicblood pressure and diastolic blood pressure whereas theother two SNPs rs2071746 and rs2071749 were not asso-ciated Although the rs2071749 has been poorly studiedwith metabolic traits in this study it was found that AAcarriers showed lower BMI values which were associatedwith the risk of presenting obesity whereas GG carriersshowed higher BMI values This is the first report showingthe association of the rs2071749 polymorphism and obesityThis polymorphism is an intronic tag SNP and it has reportedthat it is in LD with the rs3761439 which is located in
6 Oxidative Medicine and Cellular Longevity
Table 6 Association of the rs2071749 polymorphism of the HMOX1 gene with obesity
AA 261 (40) 410 (46) 0026 289 plusmn 49 0027AG + GG 390 (60) 497 (54) 295 plusmn 53Crude OR (95 CI) 125 (102ndash154) 0026OR adjusteda (95 CI) 134 (106ndash17) 0013Beta coefficient1198772b 0063003 0023BMI values are presented as mean plusmn SD BMI body mass index CI confidence interval and OR odds ratioaObesity in logistic regression was adjusted by age gender glucose triglycerides and LDL-C and HDL-C levels Genotype was included as dominant modelin logistic and multivariate analysisbLinear regression of BMI as dependent variable was adjusted by age gender glucose triglycerides and LDL-C and HDL-C levels
Table 7 Association of the rs6721961 polymorphism of the Nrf2 gene with diabetes in men
Crude OR (95 CI) 062 (046ndash085) 0003OR adjusteda (95 CI) 056 (038ndash082) 0003Crude beta coefficient minus0078 0031Glucose values (mgsdotdLminus1) are presented as mean plusmn SD CI confidence interval OR odds ratioaDiabetes in logistic regression was adjusted by age triglycerides and LDL-C and HDL-C levels Genotype was included as dominant model in logistic andlinear regressionb119875 value when comparing each genotype
c119875 value in comparison of CC with CA + AA
the promoter region of the HMOX1 gene The consensussequence of a nuclear factor 120581B (NF-120581B) binding site toHMOX1 is altered by rs3761439 polymorphism that increasesthe risk of developing impaired lung function [38] Thissuggests that the mechanisms by which this polymorphismcould be involved in obesity may be secondary to increasedoxidative stress and inflammation The results in this workopen the gate to new investigations about the role of theHMOX1 gene in Mexican obese patients
NRF2 gene regulates the enzymes studied here ManySNPs have been identified in this gene The rs35652124 andrs6721961 SNPs are predicted to affect Nrf2 myeloid zincfinger 1 (MZF1) and antioxidant response elements- (ARE-) like promoter binding sites respectively These SNPs affectthe efficient binding of proteins such as Nrf2 to theMZF1 andARE-like promoter binding sites [39]
In metabolic diseases the rs6721961 polymorphism hasbeen associated with blood pressure in Japanese subjects [39]Wang et al [7] showed that the rs6721961 polymorphism inthe NRF2 gene was significantly associated with oxidativestress antioxidant status and risk of newly diagnosed T2DMas well as with impaired insulin secretory capacity andincreased insulin resistance in T2DM patients of a Chinesepopulation Individuals with the CC genotype had lowertotal antioxidant capacity glutathione levels and superoxidedismutase catalase and glutathione peroxidase activitiesas well as lower homeostasis model assessment of 120573-cellfunction index (HOMA-120573) in comparison with individualswith the CC genotypeThosewith theAA genotype also had a
higher malondialdehyde concentration andHOMA-IR indexvalues The frequency of allele A was significantly higher inT2DM subjects (294) Individuals with the AA genotypehad a significantly higher risk of developing T2DM relativeto thosewith theCCgenotype even after adjusting for knownT2DM risk factors However this investigation showed thatthe AA carriers had lower glucose concentrations and theOR revealed that A carriers had lower risk of developingdiabetes in men after stratification by gender We had thelimitation that Nrf2 gene expression was not determined inthese patients and it is essential to elucidate the mechanismsby which the rs6721961 polymorphism can exert its protectiveeffect in our population Larger sample size could supportthis
We know that this research has some limitations Thegene expressions and activities were not determined and justcandidate genes were included Dietary information was notavailable in all patients However this study opens the gate tonew researches about the role of HMOX1 TXNIP and Nrf2in obesity diabetes and worse metabolic traits
5 Conclusions
This study shows that the rs7211 polymorphism in the TXNIPgene and the rs2071749 of the HMOX1 gene are associatedwith obesity in Mexican mestizo people In this sensers2071749 increases the risk of having obesity and the rs7211polymorphism may be a protective factor to develop obesityand to have lower concentrations of HDL-C in Mexican
Oxidative Medicine and Cellular Longevity 7
mestizo women In addition rs6721961 gen polymorphismin Nrf2 was negatively associated with diabetes in men Allof these results open the doors for new research taking intoaccount the effect onmetabolic traits andmay be useful toolsto design new therapeutic strategies in obesity and diabetestype 2
Competing Interests
The authors declare that they have no competing interests
Acknowledgments
The authors would like to acknowledge the Medical FamilyClinics from ISSSTE Ignacio Chavez Del Valle Xochimilcoand Fuentes Brotantes This work was financially supportedby CONACyT-Mexico (Grant no SALUD-2013-01-201519)
[2] R H Eckel S E Kahn E Ferrannini et al ldquoObesity andtype 2 diabetes what can be unified and what needs to beindividualizedrdquo Diabetes Care vol 34 no 6 pp 1424ndash14302011
[3] S Tyrovolas A Koyanagi NGarin et al ldquoDiabetesmellitus andits association with central obesity and disability among olderadults a global perspectiverdquo Experimental Gerontology vol 64pp 70ndash77 2015
[4] M Serrano-Rios ldquoRelationship between obesity and theincreased risk of major complications in non-insulin-depend-ent diabetesmellitusrdquo European Journal of Clinical Investigationvol 28 supplement 2 pp 14ndash18 1998
[5] S-I Yamagishi S Maeda T Matsui S Ueda K Fukami andS Okuda ldquoRole of advanced glycation end products (AGEs)and oxidative stress in vascular complications in diabetesrdquoBiochimica et Biophysica ActamdashGeneral Subjects vol 1820 no5 pp 663ndash671 2012
[6] Y-J Surh J K Kundu and H-K Na ldquoNrf2 as a master redoxswitch in turning on the cellular signaling involved in theinduction of cytoprotective genes by some chemopreventivephytochemicalsrdquo Planta Medica vol 74 no 13 pp 1526ndash15392008
[7] X Wang H Chen J Liu et al ldquoAssociation between the NF-E2related factor 2 gene polymorphism and oxidative stress anti-oxidative status and newly-diagnosed type 2 diabetes mellitusin a Chinese populationrdquo International Journal of MolecularSciences vol 16 no 7 pp 16483ndash16496 2015
[8] A S Jimenez-Osorio A Picazo S Gonzalez-Reyes D Barrera-Oviedo M E Rodrıguez-Arellano and J Pedraza-ChaverrildquoNrf2 and redox status in prediabetic and diabetic patientsrdquoInternational Journal of Molecular Sciences vol 15 no 11 pp20290ndash20305 2014
[9] J Pi L Leung P Xue et al ldquoDeficiency in the nuclear factorE2-related factor-2 transcription factor results in impairedadipogenesis and protects against diet-induced obesityrdquo TheJournal of Biological Chemistry vol 285 no 12 pp 9292ndash93002010
[10] H-Y Cho ldquoGenomic structure and variation of nuclear factor(erythroid-derived 2)-like 2rdquo Oxidative Medicine and CellularLongevity vol 2013 Article ID 286524 24 pages 2013
[11] Y Shimoyama Y Mitsuda N Hamajima and T Niwa ldquoPoly-morphisms of Nrf2 an antioxidative gene are associated withblood pressure in Japaneserdquo Nagoya Journal of Medical Sciencevol 76 no 1-2 pp 113ndash120 2014
[12] S M Figarska J M Vonk and H M Boezen ldquoNFE2L2polymorphisms mortality and metabolism in the generalpopulationrdquo Physiological Genomics vol 46 no 12 pp 411ndash4172014
[13] D Ross and D Siegel ldquoNAD(P)Hquinone oxidoreductase1 (NQO1 DT-diaphorase) functions and pharmacogeneticsrdquoMethods in Enzymology vol 382 pp 115ndash144 2004
[14] J-E Chung B C Chang K E Lee J H Kim and H S GwakldquoEffects of NAD(P)Hquinone oxidoreductase 1 polymorphismson stable warfarin doses in Korean patients with mechanicalcardiac valvesrdquo European Journal of Clinical Pharmacology vol71 no 10 pp 1229ndash1236 2015
[15] H-Y Shyu C-S Fong Y-P Fu et al ldquoGenotype polymor-phisms of GGCX NQO1 and VKORC1 genes associated withrisk susceptibility in patients with large-artery atheroscleroticstrokerdquo Clinica Chimica Acta vol 411 no 11-12 pp 840ndash8452010
[16] S J Han E S Kang H J Kim et al ldquoThe C609T variant ofNQO1 is associated with carotid artery plaques in patients withtype 2 diabetesrdquoMolecular Genetics andMetabolism vol 97 no1 pp 85ndash90 2009
[17] T Ramprasath P S Murugan E Kalaiarasan P GomathiA Rathinavel and G S Selvam ldquoGenetic association ofGlutathione peroxidase-1 (GPx-1) and NAD(P)Hquinone oxi-doreductase 1(NQO1) variants and their association of CAD inpatients with type-2 diabetesrdquoMolecular and Cellular Biochem-istry vol 361 no 1-2 pp 143ndash150 2012
[18] A Martınez-Hernandez E J Cordova O Rosillo-Salazar etal ldquoAssociation of HMOX1 and NQO1 polymorphisms withmetabolic syndrome componentsrdquo PLoS ONE vol 10 no 5Article ID e0123313 2015
[19] E Y Lee Y H Lee S H Kim et al ldquoAssociation between hemeoxygenase-1 promoter polymorphisms and the development ofalbuminuria in type 2 diabetes a case-control studyrdquoMedicinevol 94 no 43 article e1825 2015
[20] R Lin W Fu W Zhou et al ldquoAssociation of heme oxygenase-1 gene polymorphisms with essential hypertension and bloodpressure in the Chinese Han populationrdquo Genetic Testing andMolecular Biomarkers vol 15 no 1-2 pp 23ndash28 2011
[21] E Junn S H Han J Y Im et al ldquoVitamin D3 up-regulated pro-tein 1 mediates oxidative stress via suppressing the thioredoxinfunctionrdquoThe Journal of Immunology vol 164 no 12 pp 6287ndash6295 2000
[22] X He and QMa ldquoRedox regulation by nuclear factor erythroid2-related factor 2 gatekeeping for the basal and diabetes-induced expression of thioredoxin-interacting proteinrdquo Molec-ular Pharmacology vol 82 no 5 pp 887ndash897 2012
[23] M M J van Greevenbroek V M M-J Vermeulen E J MFeskens et al ldquoGenetic variation in thioredoxin interactingprotein (TXNIP) is associated with hypertriglyceridaemia andblood pressure in diabetes mellitusrdquo Diabetic Medicine vol 24no 5 pp 498ndash504 2007
[24] N E Ferreira S Omae A Pereira et al ldquoThioredoxin inter-acting protein genetic variation is associated with diabetes and
8 Oxidative Medicine and Cellular Longevity
hypertension in the Brazilian general populationrdquoAtherosclero-sis vol 221 no 1 pp 131ndash136 2012
[25] J Grimberg S Nawoschik L Belluscio R McKee A Turckand A Eisenberg ldquoA simple and efficient non-organic proce-dure for the isolation of genomic DNA from bloodrdquo NucleicAcids Research vol 17 no 20 p 8390 1989
[26] J Zuniga N Yu R Barquera et al ldquoHLA class I and class IIconserved extended haplotypes and their fragments or blocksin mexicans implications for the study of genetic diversityin admixed populationsrdquo PLoS ONE vol 8 no 9 Article IDe74442 2013
[27] P Sanz V Prieto I Flores Y Torres M Lopez-Soto andM J Farfan ldquoPopulation data of 13 STRS in southern Spain(Andalusia)rdquo Forensic Science International vol 119 no 1 pp113ndash115 2001
[28] P Calzada I Suarez S Garcıa et al ldquoThe Fang populationof Equatorial Guinea characterised by 15 STR-PCR polymor-phismsrdquo International Journal of Legal Medicine vol 119 no 2pp 107ndash110 2005
[29] C Barrot C Sanchez M Ortega et al ldquoCharacterisation ofthree Amerindian populations from Hidalgo State (Mexico)by 15 STR-PCR polymorphismsrdquo International Journal of LegalMedicine vol 119 no 2 pp 111ndash115 2005
[30] A Gonzalez-Martın A Gorostiza H Rangel-Villalobos et alldquoAnalyzing the genetic structure of the Tepehua in relation toother neighbouring Mesoamerican populations A study basedon allele frequencies of STR markersrdquo American Journal ofHuman Biology vol 20 no 5 pp 605ndash613 2008
[31] Y Tan T Ichikawa J Li et al ldquoDiabetic downregulation of Nrf2activity via ERK contributes to oxidative stress-induced insulinresistance in cardiac cells in vitro and in vivordquoDiabetes vol 60no 2 pp 625ndash633 2011
[32] H-A Seo and I-K Lee ldquoThe role of NRF2 adipocyte differen-tiation obesity and insulin resistancerdquo Oxidative Medicine andCellular Longevity vol 2013 Article ID 184598 7 pages 2013
[33] J Xu A C Donepudi V R More et al ldquoDeficiency in Nrf2transcription factor decreases adipose tissue mass and hepaticlipid accumulation in leptin-deficientmicerdquoObesity vol 23 no2 pp 335ndash344 2015
[34] A Uruno Y Yagishita and M Yamamoto ldquoThe Keap1-Nrf2system and diabetes mellitusrdquo Archives of Biochemistry andBiophysics vol 566 pp 76ndash84 2015
[35] G Wang L Zhang and Q Li ldquoGenetic polymorphisms ofGSTT1 GSTM1 and NQO1 genes and diabetes mellitus riskin Chinese populationrdquo Biochemical and Biophysical ResearchCommunications vol 341 no 2 pp 310ndash313 2006
[36] D Kim ldquoAn association between 609 CrarrT Polymorphism inNAD(P)Hquinone oxidoreductase 1 (NQO1) gene and bloodglucose levels in Korean populationrdquo Korean Diabetes Journalvol 33 no 1 pp 24ndash30 2009
[37] S K Das N K Sharma S J Hasstedt et al ldquoAn integra-tive genomics approach identifies activation of thioredoxinthioredoxin reductase-1-mediated oxidative stress defense path-way and inhibition of angiogenesis in obese nondiabetic humansubjectsrdquo The Journal of Clinical Endocrinology amp Metabolismvol 96 no 8 pp E1308ndashE1313 2011
[38] G Tanaka F Aminuddin L Akhabir et al ldquoEffect of hemeoxygenase-1 polymorphisms on lung function and gene expres-sionrdquo BMCMedical Genetics vol 12 article 117 2011
[39] Y Shimoyama Y Mitsuda Y Tsuruta N Hamajima andT Niwa ldquoPolymorphism of Nrf2 an antioxidative gene is
associated with blood pressure and cardiovascular mortalityin hemodialysis patientsrdquo International Journal of MedicalSciences vol 11 no 7 pp 726ndash731 2014
AA 261 (40) 410 (46) 0026 289 plusmn 49 0027AG + GG 390 (60) 497 (54) 295 plusmn 53Crude OR (95 CI) 125 (102ndash154) 0026OR adjusteda (95 CI) 134 (106ndash17) 0013Beta coefficient1198772b 0063003 0023BMI values are presented as mean plusmn SD BMI body mass index CI confidence interval and OR odds ratioaObesity in logistic regression was adjusted by age gender glucose triglycerides and LDL-C and HDL-C levels Genotype was included as dominant modelin logistic and multivariate analysisbLinear regression of BMI as dependent variable was adjusted by age gender glucose triglycerides and LDL-C and HDL-C levels
Table 7 Association of the rs6721961 polymorphism of the Nrf2 gene with diabetes in men
Crude OR (95 CI) 062 (046ndash085) 0003OR adjusteda (95 CI) 056 (038ndash082) 0003Crude beta coefficient minus0078 0031Glucose values (mgsdotdLminus1) are presented as mean plusmn SD CI confidence interval OR odds ratioaDiabetes in logistic regression was adjusted by age triglycerides and LDL-C and HDL-C levels Genotype was included as dominant model in logistic andlinear regressionb119875 value when comparing each genotype
c119875 value in comparison of CC with CA + AA
the promoter region of the HMOX1 gene The consensussequence of a nuclear factor 120581B (NF-120581B) binding site toHMOX1 is altered by rs3761439 polymorphism that increasesthe risk of developing impaired lung function [38] Thissuggests that the mechanisms by which this polymorphismcould be involved in obesity may be secondary to increasedoxidative stress and inflammation The results in this workopen the gate to new investigations about the role of theHMOX1 gene in Mexican obese patients
NRF2 gene regulates the enzymes studied here ManySNPs have been identified in this gene The rs35652124 andrs6721961 SNPs are predicted to affect Nrf2 myeloid zincfinger 1 (MZF1) and antioxidant response elements- (ARE-) like promoter binding sites respectively These SNPs affectthe efficient binding of proteins such as Nrf2 to theMZF1 andARE-like promoter binding sites [39]
In metabolic diseases the rs6721961 polymorphism hasbeen associated with blood pressure in Japanese subjects [39]Wang et al [7] showed that the rs6721961 polymorphism inthe NRF2 gene was significantly associated with oxidativestress antioxidant status and risk of newly diagnosed T2DMas well as with impaired insulin secretory capacity andincreased insulin resistance in T2DM patients of a Chinesepopulation Individuals with the CC genotype had lowertotal antioxidant capacity glutathione levels and superoxidedismutase catalase and glutathione peroxidase activitiesas well as lower homeostasis model assessment of 120573-cellfunction index (HOMA-120573) in comparison with individualswith the CC genotypeThosewith theAA genotype also had a
higher malondialdehyde concentration andHOMA-IR indexvalues The frequency of allele A was significantly higher inT2DM subjects (294) Individuals with the AA genotypehad a significantly higher risk of developing T2DM relativeto thosewith theCCgenotype even after adjusting for knownT2DM risk factors However this investigation showed thatthe AA carriers had lower glucose concentrations and theOR revealed that A carriers had lower risk of developingdiabetes in men after stratification by gender We had thelimitation that Nrf2 gene expression was not determined inthese patients and it is essential to elucidate the mechanismsby which the rs6721961 polymorphism can exert its protectiveeffect in our population Larger sample size could supportthis
We know that this research has some limitations Thegene expressions and activities were not determined and justcandidate genes were included Dietary information was notavailable in all patients However this study opens the gate tonew researches about the role of HMOX1 TXNIP and Nrf2in obesity diabetes and worse metabolic traits
5 Conclusions
This study shows that the rs7211 polymorphism in the TXNIPgene and the rs2071749 of the HMOX1 gene are associatedwith obesity in Mexican mestizo people In this sensers2071749 increases the risk of having obesity and the rs7211polymorphism may be a protective factor to develop obesityand to have lower concentrations of HDL-C in Mexican
Oxidative Medicine and Cellular Longevity 7
mestizo women In addition rs6721961 gen polymorphismin Nrf2 was negatively associated with diabetes in men Allof these results open the doors for new research taking intoaccount the effect onmetabolic traits andmay be useful toolsto design new therapeutic strategies in obesity and diabetestype 2
Competing Interests
The authors declare that they have no competing interests
Acknowledgments
The authors would like to acknowledge the Medical FamilyClinics from ISSSTE Ignacio Chavez Del Valle Xochimilcoand Fuentes Brotantes This work was financially supportedby CONACyT-Mexico (Grant no SALUD-2013-01-201519)
[2] R H Eckel S E Kahn E Ferrannini et al ldquoObesity andtype 2 diabetes what can be unified and what needs to beindividualizedrdquo Diabetes Care vol 34 no 6 pp 1424ndash14302011
[3] S Tyrovolas A Koyanagi NGarin et al ldquoDiabetesmellitus andits association with central obesity and disability among olderadults a global perspectiverdquo Experimental Gerontology vol 64pp 70ndash77 2015
[4] M Serrano-Rios ldquoRelationship between obesity and theincreased risk of major complications in non-insulin-depend-ent diabetesmellitusrdquo European Journal of Clinical Investigationvol 28 supplement 2 pp 14ndash18 1998
[5] S-I Yamagishi S Maeda T Matsui S Ueda K Fukami andS Okuda ldquoRole of advanced glycation end products (AGEs)and oxidative stress in vascular complications in diabetesrdquoBiochimica et Biophysica ActamdashGeneral Subjects vol 1820 no5 pp 663ndash671 2012
[6] Y-J Surh J K Kundu and H-K Na ldquoNrf2 as a master redoxswitch in turning on the cellular signaling involved in theinduction of cytoprotective genes by some chemopreventivephytochemicalsrdquo Planta Medica vol 74 no 13 pp 1526ndash15392008
[7] X Wang H Chen J Liu et al ldquoAssociation between the NF-E2related factor 2 gene polymorphism and oxidative stress anti-oxidative status and newly-diagnosed type 2 diabetes mellitusin a Chinese populationrdquo International Journal of MolecularSciences vol 16 no 7 pp 16483ndash16496 2015
[8] A S Jimenez-Osorio A Picazo S Gonzalez-Reyes D Barrera-Oviedo M E Rodrıguez-Arellano and J Pedraza-ChaverrildquoNrf2 and redox status in prediabetic and diabetic patientsrdquoInternational Journal of Molecular Sciences vol 15 no 11 pp20290ndash20305 2014
[9] J Pi L Leung P Xue et al ldquoDeficiency in the nuclear factorE2-related factor-2 transcription factor results in impairedadipogenesis and protects against diet-induced obesityrdquo TheJournal of Biological Chemistry vol 285 no 12 pp 9292ndash93002010
[10] H-Y Cho ldquoGenomic structure and variation of nuclear factor(erythroid-derived 2)-like 2rdquo Oxidative Medicine and CellularLongevity vol 2013 Article ID 286524 24 pages 2013
[11] Y Shimoyama Y Mitsuda N Hamajima and T Niwa ldquoPoly-morphisms of Nrf2 an antioxidative gene are associated withblood pressure in Japaneserdquo Nagoya Journal of Medical Sciencevol 76 no 1-2 pp 113ndash120 2014
[12] S M Figarska J M Vonk and H M Boezen ldquoNFE2L2polymorphisms mortality and metabolism in the generalpopulationrdquo Physiological Genomics vol 46 no 12 pp 411ndash4172014
[13] D Ross and D Siegel ldquoNAD(P)Hquinone oxidoreductase1 (NQO1 DT-diaphorase) functions and pharmacogeneticsrdquoMethods in Enzymology vol 382 pp 115ndash144 2004
[14] J-E Chung B C Chang K E Lee J H Kim and H S GwakldquoEffects of NAD(P)Hquinone oxidoreductase 1 polymorphismson stable warfarin doses in Korean patients with mechanicalcardiac valvesrdquo European Journal of Clinical Pharmacology vol71 no 10 pp 1229ndash1236 2015
[15] H-Y Shyu C-S Fong Y-P Fu et al ldquoGenotype polymor-phisms of GGCX NQO1 and VKORC1 genes associated withrisk susceptibility in patients with large-artery atheroscleroticstrokerdquo Clinica Chimica Acta vol 411 no 11-12 pp 840ndash8452010
[16] S J Han E S Kang H J Kim et al ldquoThe C609T variant ofNQO1 is associated with carotid artery plaques in patients withtype 2 diabetesrdquoMolecular Genetics andMetabolism vol 97 no1 pp 85ndash90 2009
[17] T Ramprasath P S Murugan E Kalaiarasan P GomathiA Rathinavel and G S Selvam ldquoGenetic association ofGlutathione peroxidase-1 (GPx-1) and NAD(P)Hquinone oxi-doreductase 1(NQO1) variants and their association of CAD inpatients with type-2 diabetesrdquoMolecular and Cellular Biochem-istry vol 361 no 1-2 pp 143ndash150 2012
[18] A Martınez-Hernandez E J Cordova O Rosillo-Salazar etal ldquoAssociation of HMOX1 and NQO1 polymorphisms withmetabolic syndrome componentsrdquo PLoS ONE vol 10 no 5Article ID e0123313 2015
[19] E Y Lee Y H Lee S H Kim et al ldquoAssociation between hemeoxygenase-1 promoter polymorphisms and the development ofalbuminuria in type 2 diabetes a case-control studyrdquoMedicinevol 94 no 43 article e1825 2015
[20] R Lin W Fu W Zhou et al ldquoAssociation of heme oxygenase-1 gene polymorphisms with essential hypertension and bloodpressure in the Chinese Han populationrdquo Genetic Testing andMolecular Biomarkers vol 15 no 1-2 pp 23ndash28 2011
[21] E Junn S H Han J Y Im et al ldquoVitamin D3 up-regulated pro-tein 1 mediates oxidative stress via suppressing the thioredoxinfunctionrdquoThe Journal of Immunology vol 164 no 12 pp 6287ndash6295 2000
[22] X He and QMa ldquoRedox regulation by nuclear factor erythroid2-related factor 2 gatekeeping for the basal and diabetes-induced expression of thioredoxin-interacting proteinrdquo Molec-ular Pharmacology vol 82 no 5 pp 887ndash897 2012
[23] M M J van Greevenbroek V M M-J Vermeulen E J MFeskens et al ldquoGenetic variation in thioredoxin interactingprotein (TXNIP) is associated with hypertriglyceridaemia andblood pressure in diabetes mellitusrdquo Diabetic Medicine vol 24no 5 pp 498ndash504 2007
[24] N E Ferreira S Omae A Pereira et al ldquoThioredoxin inter-acting protein genetic variation is associated with diabetes and
8 Oxidative Medicine and Cellular Longevity
hypertension in the Brazilian general populationrdquoAtherosclero-sis vol 221 no 1 pp 131ndash136 2012
[25] J Grimberg S Nawoschik L Belluscio R McKee A Turckand A Eisenberg ldquoA simple and efficient non-organic proce-dure for the isolation of genomic DNA from bloodrdquo NucleicAcids Research vol 17 no 20 p 8390 1989
[26] J Zuniga N Yu R Barquera et al ldquoHLA class I and class IIconserved extended haplotypes and their fragments or blocksin mexicans implications for the study of genetic diversityin admixed populationsrdquo PLoS ONE vol 8 no 9 Article IDe74442 2013
[27] P Sanz V Prieto I Flores Y Torres M Lopez-Soto andM J Farfan ldquoPopulation data of 13 STRS in southern Spain(Andalusia)rdquo Forensic Science International vol 119 no 1 pp113ndash115 2001
[28] P Calzada I Suarez S Garcıa et al ldquoThe Fang populationof Equatorial Guinea characterised by 15 STR-PCR polymor-phismsrdquo International Journal of Legal Medicine vol 119 no 2pp 107ndash110 2005
[29] C Barrot C Sanchez M Ortega et al ldquoCharacterisation ofthree Amerindian populations from Hidalgo State (Mexico)by 15 STR-PCR polymorphismsrdquo International Journal of LegalMedicine vol 119 no 2 pp 111ndash115 2005
[30] A Gonzalez-Martın A Gorostiza H Rangel-Villalobos et alldquoAnalyzing the genetic structure of the Tepehua in relation toother neighbouring Mesoamerican populations A study basedon allele frequencies of STR markersrdquo American Journal ofHuman Biology vol 20 no 5 pp 605ndash613 2008
[31] Y Tan T Ichikawa J Li et al ldquoDiabetic downregulation of Nrf2activity via ERK contributes to oxidative stress-induced insulinresistance in cardiac cells in vitro and in vivordquoDiabetes vol 60no 2 pp 625ndash633 2011
[32] H-A Seo and I-K Lee ldquoThe role of NRF2 adipocyte differen-tiation obesity and insulin resistancerdquo Oxidative Medicine andCellular Longevity vol 2013 Article ID 184598 7 pages 2013
[33] J Xu A C Donepudi V R More et al ldquoDeficiency in Nrf2transcription factor decreases adipose tissue mass and hepaticlipid accumulation in leptin-deficientmicerdquoObesity vol 23 no2 pp 335ndash344 2015
[34] A Uruno Y Yagishita and M Yamamoto ldquoThe Keap1-Nrf2system and diabetes mellitusrdquo Archives of Biochemistry andBiophysics vol 566 pp 76ndash84 2015
[35] G Wang L Zhang and Q Li ldquoGenetic polymorphisms ofGSTT1 GSTM1 and NQO1 genes and diabetes mellitus riskin Chinese populationrdquo Biochemical and Biophysical ResearchCommunications vol 341 no 2 pp 310ndash313 2006
[36] D Kim ldquoAn association between 609 CrarrT Polymorphism inNAD(P)Hquinone oxidoreductase 1 (NQO1) gene and bloodglucose levels in Korean populationrdquo Korean Diabetes Journalvol 33 no 1 pp 24ndash30 2009
[37] S K Das N K Sharma S J Hasstedt et al ldquoAn integra-tive genomics approach identifies activation of thioredoxinthioredoxin reductase-1-mediated oxidative stress defense path-way and inhibition of angiogenesis in obese nondiabetic humansubjectsrdquo The Journal of Clinical Endocrinology amp Metabolismvol 96 no 8 pp E1308ndashE1313 2011
[38] G Tanaka F Aminuddin L Akhabir et al ldquoEffect of hemeoxygenase-1 polymorphisms on lung function and gene expres-sionrdquo BMCMedical Genetics vol 12 article 117 2011
[39] Y Shimoyama Y Mitsuda Y Tsuruta N Hamajima andT Niwa ldquoPolymorphism of Nrf2 an antioxidative gene is
associated with blood pressure and cardiovascular mortalityin hemodialysis patientsrdquo International Journal of MedicalSciences vol 11 no 7 pp 726ndash731 2014
mestizo women In addition rs6721961 gen polymorphismin Nrf2 was negatively associated with diabetes in men Allof these results open the doors for new research taking intoaccount the effect onmetabolic traits andmay be useful toolsto design new therapeutic strategies in obesity and diabetestype 2
Competing Interests
The authors declare that they have no competing interests
Acknowledgments
The authors would like to acknowledge the Medical FamilyClinics from ISSSTE Ignacio Chavez Del Valle Xochimilcoand Fuentes Brotantes This work was financially supportedby CONACyT-Mexico (Grant no SALUD-2013-01-201519)
[2] R H Eckel S E Kahn E Ferrannini et al ldquoObesity andtype 2 diabetes what can be unified and what needs to beindividualizedrdquo Diabetes Care vol 34 no 6 pp 1424ndash14302011
[3] S Tyrovolas A Koyanagi NGarin et al ldquoDiabetesmellitus andits association with central obesity and disability among olderadults a global perspectiverdquo Experimental Gerontology vol 64pp 70ndash77 2015
[4] M Serrano-Rios ldquoRelationship between obesity and theincreased risk of major complications in non-insulin-depend-ent diabetesmellitusrdquo European Journal of Clinical Investigationvol 28 supplement 2 pp 14ndash18 1998
[5] S-I Yamagishi S Maeda T Matsui S Ueda K Fukami andS Okuda ldquoRole of advanced glycation end products (AGEs)and oxidative stress in vascular complications in diabetesrdquoBiochimica et Biophysica ActamdashGeneral Subjects vol 1820 no5 pp 663ndash671 2012
[6] Y-J Surh J K Kundu and H-K Na ldquoNrf2 as a master redoxswitch in turning on the cellular signaling involved in theinduction of cytoprotective genes by some chemopreventivephytochemicalsrdquo Planta Medica vol 74 no 13 pp 1526ndash15392008
[7] X Wang H Chen J Liu et al ldquoAssociation between the NF-E2related factor 2 gene polymorphism and oxidative stress anti-oxidative status and newly-diagnosed type 2 diabetes mellitusin a Chinese populationrdquo International Journal of MolecularSciences vol 16 no 7 pp 16483ndash16496 2015
[8] A S Jimenez-Osorio A Picazo S Gonzalez-Reyes D Barrera-Oviedo M E Rodrıguez-Arellano and J Pedraza-ChaverrildquoNrf2 and redox status in prediabetic and diabetic patientsrdquoInternational Journal of Molecular Sciences vol 15 no 11 pp20290ndash20305 2014
[9] J Pi L Leung P Xue et al ldquoDeficiency in the nuclear factorE2-related factor-2 transcription factor results in impairedadipogenesis and protects against diet-induced obesityrdquo TheJournal of Biological Chemistry vol 285 no 12 pp 9292ndash93002010
[10] H-Y Cho ldquoGenomic structure and variation of nuclear factor(erythroid-derived 2)-like 2rdquo Oxidative Medicine and CellularLongevity vol 2013 Article ID 286524 24 pages 2013
[11] Y Shimoyama Y Mitsuda N Hamajima and T Niwa ldquoPoly-morphisms of Nrf2 an antioxidative gene are associated withblood pressure in Japaneserdquo Nagoya Journal of Medical Sciencevol 76 no 1-2 pp 113ndash120 2014
[12] S M Figarska J M Vonk and H M Boezen ldquoNFE2L2polymorphisms mortality and metabolism in the generalpopulationrdquo Physiological Genomics vol 46 no 12 pp 411ndash4172014
[13] D Ross and D Siegel ldquoNAD(P)Hquinone oxidoreductase1 (NQO1 DT-diaphorase) functions and pharmacogeneticsrdquoMethods in Enzymology vol 382 pp 115ndash144 2004
[14] J-E Chung B C Chang K E Lee J H Kim and H S GwakldquoEffects of NAD(P)Hquinone oxidoreductase 1 polymorphismson stable warfarin doses in Korean patients with mechanicalcardiac valvesrdquo European Journal of Clinical Pharmacology vol71 no 10 pp 1229ndash1236 2015
[15] H-Y Shyu C-S Fong Y-P Fu et al ldquoGenotype polymor-phisms of GGCX NQO1 and VKORC1 genes associated withrisk susceptibility in patients with large-artery atheroscleroticstrokerdquo Clinica Chimica Acta vol 411 no 11-12 pp 840ndash8452010
[16] S J Han E S Kang H J Kim et al ldquoThe C609T variant ofNQO1 is associated with carotid artery plaques in patients withtype 2 diabetesrdquoMolecular Genetics andMetabolism vol 97 no1 pp 85ndash90 2009
[17] T Ramprasath P S Murugan E Kalaiarasan P GomathiA Rathinavel and G S Selvam ldquoGenetic association ofGlutathione peroxidase-1 (GPx-1) and NAD(P)Hquinone oxi-doreductase 1(NQO1) variants and their association of CAD inpatients with type-2 diabetesrdquoMolecular and Cellular Biochem-istry vol 361 no 1-2 pp 143ndash150 2012
[18] A Martınez-Hernandez E J Cordova O Rosillo-Salazar etal ldquoAssociation of HMOX1 and NQO1 polymorphisms withmetabolic syndrome componentsrdquo PLoS ONE vol 10 no 5Article ID e0123313 2015
[19] E Y Lee Y H Lee S H Kim et al ldquoAssociation between hemeoxygenase-1 promoter polymorphisms and the development ofalbuminuria in type 2 diabetes a case-control studyrdquoMedicinevol 94 no 43 article e1825 2015
[20] R Lin W Fu W Zhou et al ldquoAssociation of heme oxygenase-1 gene polymorphisms with essential hypertension and bloodpressure in the Chinese Han populationrdquo Genetic Testing andMolecular Biomarkers vol 15 no 1-2 pp 23ndash28 2011
[21] E Junn S H Han J Y Im et al ldquoVitamin D3 up-regulated pro-tein 1 mediates oxidative stress via suppressing the thioredoxinfunctionrdquoThe Journal of Immunology vol 164 no 12 pp 6287ndash6295 2000
[22] X He and QMa ldquoRedox regulation by nuclear factor erythroid2-related factor 2 gatekeeping for the basal and diabetes-induced expression of thioredoxin-interacting proteinrdquo Molec-ular Pharmacology vol 82 no 5 pp 887ndash897 2012
[23] M M J van Greevenbroek V M M-J Vermeulen E J MFeskens et al ldquoGenetic variation in thioredoxin interactingprotein (TXNIP) is associated with hypertriglyceridaemia andblood pressure in diabetes mellitusrdquo Diabetic Medicine vol 24no 5 pp 498ndash504 2007
[24] N E Ferreira S Omae A Pereira et al ldquoThioredoxin inter-acting protein genetic variation is associated with diabetes and
8 Oxidative Medicine and Cellular Longevity
hypertension in the Brazilian general populationrdquoAtherosclero-sis vol 221 no 1 pp 131ndash136 2012
[25] J Grimberg S Nawoschik L Belluscio R McKee A Turckand A Eisenberg ldquoA simple and efficient non-organic proce-dure for the isolation of genomic DNA from bloodrdquo NucleicAcids Research vol 17 no 20 p 8390 1989
[26] J Zuniga N Yu R Barquera et al ldquoHLA class I and class IIconserved extended haplotypes and their fragments or blocksin mexicans implications for the study of genetic diversityin admixed populationsrdquo PLoS ONE vol 8 no 9 Article IDe74442 2013
[27] P Sanz V Prieto I Flores Y Torres M Lopez-Soto andM J Farfan ldquoPopulation data of 13 STRS in southern Spain(Andalusia)rdquo Forensic Science International vol 119 no 1 pp113ndash115 2001
[28] P Calzada I Suarez S Garcıa et al ldquoThe Fang populationof Equatorial Guinea characterised by 15 STR-PCR polymor-phismsrdquo International Journal of Legal Medicine vol 119 no 2pp 107ndash110 2005
[29] C Barrot C Sanchez M Ortega et al ldquoCharacterisation ofthree Amerindian populations from Hidalgo State (Mexico)by 15 STR-PCR polymorphismsrdquo International Journal of LegalMedicine vol 119 no 2 pp 111ndash115 2005
[30] A Gonzalez-Martın A Gorostiza H Rangel-Villalobos et alldquoAnalyzing the genetic structure of the Tepehua in relation toother neighbouring Mesoamerican populations A study basedon allele frequencies of STR markersrdquo American Journal ofHuman Biology vol 20 no 5 pp 605ndash613 2008
[31] Y Tan T Ichikawa J Li et al ldquoDiabetic downregulation of Nrf2activity via ERK contributes to oxidative stress-induced insulinresistance in cardiac cells in vitro and in vivordquoDiabetes vol 60no 2 pp 625ndash633 2011
[32] H-A Seo and I-K Lee ldquoThe role of NRF2 adipocyte differen-tiation obesity and insulin resistancerdquo Oxidative Medicine andCellular Longevity vol 2013 Article ID 184598 7 pages 2013
[33] J Xu A C Donepudi V R More et al ldquoDeficiency in Nrf2transcription factor decreases adipose tissue mass and hepaticlipid accumulation in leptin-deficientmicerdquoObesity vol 23 no2 pp 335ndash344 2015
[34] A Uruno Y Yagishita and M Yamamoto ldquoThe Keap1-Nrf2system and diabetes mellitusrdquo Archives of Biochemistry andBiophysics vol 566 pp 76ndash84 2015
[35] G Wang L Zhang and Q Li ldquoGenetic polymorphisms ofGSTT1 GSTM1 and NQO1 genes and diabetes mellitus riskin Chinese populationrdquo Biochemical and Biophysical ResearchCommunications vol 341 no 2 pp 310ndash313 2006
[36] D Kim ldquoAn association between 609 CrarrT Polymorphism inNAD(P)Hquinone oxidoreductase 1 (NQO1) gene and bloodglucose levels in Korean populationrdquo Korean Diabetes Journalvol 33 no 1 pp 24ndash30 2009
[37] S K Das N K Sharma S J Hasstedt et al ldquoAn integra-tive genomics approach identifies activation of thioredoxinthioredoxin reductase-1-mediated oxidative stress defense path-way and inhibition of angiogenesis in obese nondiabetic humansubjectsrdquo The Journal of Clinical Endocrinology amp Metabolismvol 96 no 8 pp E1308ndashE1313 2011
[38] G Tanaka F Aminuddin L Akhabir et al ldquoEffect of hemeoxygenase-1 polymorphisms on lung function and gene expres-sionrdquo BMCMedical Genetics vol 12 article 117 2011
[39] Y Shimoyama Y Mitsuda Y Tsuruta N Hamajima andT Niwa ldquoPolymorphism of Nrf2 an antioxidative gene is
associated with blood pressure and cardiovascular mortalityin hemodialysis patientsrdquo International Journal of MedicalSciences vol 11 no 7 pp 726ndash731 2014
hypertension in the Brazilian general populationrdquoAtherosclero-sis vol 221 no 1 pp 131ndash136 2012
[25] J Grimberg S Nawoschik L Belluscio R McKee A Turckand A Eisenberg ldquoA simple and efficient non-organic proce-dure for the isolation of genomic DNA from bloodrdquo NucleicAcids Research vol 17 no 20 p 8390 1989
[26] J Zuniga N Yu R Barquera et al ldquoHLA class I and class IIconserved extended haplotypes and their fragments or blocksin mexicans implications for the study of genetic diversityin admixed populationsrdquo PLoS ONE vol 8 no 9 Article IDe74442 2013
[27] P Sanz V Prieto I Flores Y Torres M Lopez-Soto andM J Farfan ldquoPopulation data of 13 STRS in southern Spain(Andalusia)rdquo Forensic Science International vol 119 no 1 pp113ndash115 2001
[28] P Calzada I Suarez S Garcıa et al ldquoThe Fang populationof Equatorial Guinea characterised by 15 STR-PCR polymor-phismsrdquo International Journal of Legal Medicine vol 119 no 2pp 107ndash110 2005
[29] C Barrot C Sanchez M Ortega et al ldquoCharacterisation ofthree Amerindian populations from Hidalgo State (Mexico)by 15 STR-PCR polymorphismsrdquo International Journal of LegalMedicine vol 119 no 2 pp 111ndash115 2005
[30] A Gonzalez-Martın A Gorostiza H Rangel-Villalobos et alldquoAnalyzing the genetic structure of the Tepehua in relation toother neighbouring Mesoamerican populations A study basedon allele frequencies of STR markersrdquo American Journal ofHuman Biology vol 20 no 5 pp 605ndash613 2008
[31] Y Tan T Ichikawa J Li et al ldquoDiabetic downregulation of Nrf2activity via ERK contributes to oxidative stress-induced insulinresistance in cardiac cells in vitro and in vivordquoDiabetes vol 60no 2 pp 625ndash633 2011
[32] H-A Seo and I-K Lee ldquoThe role of NRF2 adipocyte differen-tiation obesity and insulin resistancerdquo Oxidative Medicine andCellular Longevity vol 2013 Article ID 184598 7 pages 2013
[33] J Xu A C Donepudi V R More et al ldquoDeficiency in Nrf2transcription factor decreases adipose tissue mass and hepaticlipid accumulation in leptin-deficientmicerdquoObesity vol 23 no2 pp 335ndash344 2015
[34] A Uruno Y Yagishita and M Yamamoto ldquoThe Keap1-Nrf2system and diabetes mellitusrdquo Archives of Biochemistry andBiophysics vol 566 pp 76ndash84 2015
[35] G Wang L Zhang and Q Li ldquoGenetic polymorphisms ofGSTT1 GSTM1 and NQO1 genes and diabetes mellitus riskin Chinese populationrdquo Biochemical and Biophysical ResearchCommunications vol 341 no 2 pp 310ndash313 2006
[36] D Kim ldquoAn association between 609 CrarrT Polymorphism inNAD(P)Hquinone oxidoreductase 1 (NQO1) gene and bloodglucose levels in Korean populationrdquo Korean Diabetes Journalvol 33 no 1 pp 24ndash30 2009
[37] S K Das N K Sharma S J Hasstedt et al ldquoAn integra-tive genomics approach identifies activation of thioredoxinthioredoxin reductase-1-mediated oxidative stress defense path-way and inhibition of angiogenesis in obese nondiabetic humansubjectsrdquo The Journal of Clinical Endocrinology amp Metabolismvol 96 no 8 pp E1308ndashE1313 2011
[38] G Tanaka F Aminuddin L Akhabir et al ldquoEffect of hemeoxygenase-1 polymorphisms on lung function and gene expres-sionrdquo BMCMedical Genetics vol 12 article 117 2011
[39] Y Shimoyama Y Mitsuda Y Tsuruta N Hamajima andT Niwa ldquoPolymorphism of Nrf2 an antioxidative gene is
associated with blood pressure and cardiovascular mortalityin hemodialysis patientsrdquo International Journal of MedicalSciences vol 11 no 7 pp 726ndash731 2014
