Proteomics investigation into cardiac endothelial cells using the Orbitrap at the Proteomics facility of
the University of Stellenbosch
Salome Smit
Central Analytical Facility University of Stellenbosch
Overview
1. Proteomics analysis of cardiac endothelial cells2. SILAC experiment with HIV-1Tat protein3. Summary
• Vascular endothelium long thought to be a mere selectively permeable barrier between the circulation and sub-endothelial tissues, is now known to be a master regulator of vascular homeostasis, • Controlling functions such as vasomotor activity, thrombosis, inflammation and redox balance • When endothelial function becomes compromised as observed in cardiovascular risk conditions such as diabetes mellitus, vascular homeostasis is lost resulting in increased oxidative stress, a loss of nitric oxide (NO) bioavailability, increased endothelial cell expression of pro-inflammatory vascular adhesion molecules and increased endothelial permeability.
•These pathophysiological changes underlie the phenomena of endothelial activation and endothelial dysfunction, of which the latter in particular is regarded as the early forerunner of atherosclerosis.
All slides for CMEC work courtesy of Prof Hans Strijdom, University of Stellenbosch
CARDIAC MICROVASCULAR ENDOTHELIAL CELLS = CMECs
CMECs• In the heart, the myocardial capillaries (leading to ischaemic
heart disease) are made up of cardiac microvascular endothelial cells (CMECs).
• CMECs show distinct structural and functional adaptations compared to other endothelial cell phenotypes in view of their location in the myocardium where they are closely associated with surrounding cardiomyocytes.
• There is intimate CMEC-cardiomyocyte arrangement
• cardiomyocytes are regarded as the primary cellular recipients of paracrine messengers secreted by CMECs, such as NO and endothelin-1.
CMECs• CMECs: PIVOTAL ROLE IN BOTH MYOCARDIAL FUNCTION AND INJURY
• Optimal diffusion of oxygen and nutrients
• Reciprocal signalling with cardiomyocytes
• Regulate cardiomyocyte growth and development
• Regulation of cardiomyocyte contractile function & rhythmicity
• Therefore, CMECs are now recognized as important regulators of myocardial function.
TNF-α: RELEASE, BINDING AND EFFECTS
TNF-R1 TNF-R2
APOPTOSISINFLAMMATORY RESPONSE / PRO-SURVIVAL
Inflammation; Tissue Injury (eg Ischaemia); Aging; Cardiovascular Risk Factors (Obesity; DM);
Heart Failure
↑TNF-α Release
ANTI-APOPTOSIS / ANTI-NECROSIS
Vascular endothelial cells are the PRIMARY targets of circulating TNF-α (Pober 2004); Express both TNF-R1 and TNF-R2
(Madge 2001)
What is the effect of TNF-α on CMEC?
What would be a novel and optimal method to study these cells? To gain the most
information
METHODS: LARGE-SCALE PROTEOMICS: LTQ Orbitrap Velos MS (Thermo Scientific): Central Analytical Facility, FHS, Univ Stellenbosch SDS-PAGE
IN-GEL TRYPSINISATION
NANO LIQUID CHROMATOGRAPHY
MASS SPECTOMETRY
PROTEIN ID
• Relatively few papers measure large-scale protein expression and regulation in vascular endothelial cells of any type (“only” 350 since 2001): Surprising! (Richardson 2010)•Pubmed search: <5 papers reported on any form of proteomic analysis performed on CMECs
Control TNF-α
Control Down226
TNF-αUp
269
Shared: 1214
Sieve™: 1511 proteinsControl TNF-α
Control Down
77
TNF-α Up143
Shared: 1056
Maxquant™: 1102 proteins
TNF-α: 5ng / ml ; 24h
PROTEIN REGULATION:
UP REGULATED AND TNF-α ONLY:
DAVID Bioinformatics Resources®
16 proteins
UP REGULATED AND TNF-α ONLY:
DAVID Bioinformatics Resources®
MITOCHONDRIAL PROTEINS:
• ATP Synthase subunits (TNF only);• Acetyltransferase component of Pyruvate dehydrogenase (3-fold);• Carnitine-Acylcarnitine carrier protein (3-fold);• Acyl CoA dehydrogenase ( 5-fold);• Isocitrate dehydrogenase (only TNF);• ADP/ATP translocase 2 ( 7.6-fold);• Cytochrome C1 ( 2-fold);• Electron transfer flavoprotein ( 2-fold);• VDAC-1 ( 2-fold);• Cytochrome C1 ( 2-fold);• Cytochrome C oxidase (TNF only);• Glycerol-3-phosphate dehydrogenase (TNF only)
51 proteins
UP REGULATED AND TNF-α ONLY:
DAVID Bioinformatics Resources®
13 proteins
UP REGULATED AND TNF-α ONLY:
Function, pathway, process P-valueNucleic Acid Metabolism 0.000004
Protein Synthesis 0.00006
Protein Trafficking 0.00009
EIF-2 Signalling 0.000015
Glutathione Metabolism 0.0004
Interleukin Signalling 0.0007
Oxidative Stress 4x10-7
Mitochondrial Dysfunction 0.008
Ingenuity® Systems
DOWN REGULATED AND CONTROL ONLY:
DAVID Bioinformatics Resources®
27 proteins
CYTOSKELETON PROTEINS:
• ADP Ribosylation Factor ( 5-fold);• Actin, alpha-1 ( 4-fold);• Actin, gamma-1 (control only);• Alpha actinin-4 ( 4-fold);• Cofilin-1 (5.5-fold);• Gelsolin ( 43-fold);• Tubulin, beta 2 ( 31-fold);• R-ras ( 52-fold)
DOWN REGULATED AND CONTROL ONLY:
Function, pathway, process P-valueCellular Assembly & Organisation 1.7 x 10-9
Cellular Function & Maintenance 1.7 x 10-9
Cell Morphology 1.7 x 10-7
Cellular Growth & Proliferation 3.8 x 10-7
Integrin Signalling 2.4 x 10-10
Caveolar-mediated Endocytosis 4.5 x 10-9
Clathrin-mediated Endocytosis 3.3 x 10-8
Actin Cytoskeleton Signalling 2.7 x 10-7
Ingenuity® Systems
EVIDENCE OF TNF-α SIGNALLING:
TRADD
• TNF-R1 and Death Associated Protein (TRADD): Expressed only in TNF-α stimulated cells • NF-κB: Expressed only in TNF-α stimulated cells
Proteomics:
• Complement C4 (2.2-fold); • ICAM-1 (only TNF-α); • MHC Class 1 (1.6-fold); • IL-1 (TNF-α only)
Inflammatory / Immune Protein Expression:
IκB-α
β-tubulin
Control 0.5ng/ml 5ng/ml 20ng/ml
IκB EXPRESSION
eNOS-NO Pathway:• eNOS: 27%• eNOS: 63%• NO: 44%• NO: 33%• NO: 23%
NOS-NO BIOSYNTHESIS PATHWAYS:
Control TNF-α 5ng/ml
p-PKB
t-PKB
PKB/Akt REGULATION AND ACTIVATION
PROTEOMICS:• Heat shock protein 90-α (5.8-fold)• Heat shock protein 90-β (42-fold)
HEAT SHOCK PROTEIN 90 EXPRESSION
HSP90
β- tubulin
Control TNF 0.5ng TNF 0.5ng TNF 20ngNO PRODUCTION
Oxidative Stress:• ROS: 63% of studies • Nitrosative stress: 25% of studies• NADPH-oxidase: 25% of studies• ROS included: Superoxide (50%),
mito- ROS (25%) and H2O2 (13%)
PROTEOMIC DATA SUGGEST ANTI-OXIDANT PROTEINS AND OXIDATVE STRESS RESPONSE:
PROTEOMICS:
• Park-7 ( 2-fold )• SOD [Mn], mitochondrial (2-fold)• Thioredoxin ( 3-fold)• Glutathione-s-transferase (only in TNF)• Glutathione peroxidase, GPX4 (only TNF)• Peroxiredoxin (2-fold)
Function, pathway, process P-valueGlutathione Metabolism 0.0004
Oxidative Stress 4x10-7
DAVID Bioinformatics Resources®
Ingenuity® Systems
Control 0.5ng/ml 5ng/ml
p22-phox
β-tubulin
P22-PHOX EXPRESSION
OXIDATIVE STRESS PARAMETERS:
20ng/ml
MITOCHONDRIAL ROS PRODUCTION:
Control: + MitoSoxTM20 µm
TNF-α: + MitoSoxTM
20 µm
FACS confirmed results
Thus proteomic results confirmed
Apoptosis / Cell Death:• Apoptosis: 50% of studies • Apoptosis: 38% of studies• Necrosis: 13% of studies
APOPTOSIS / CELL DEATH:
PROTEOMICS:
• Bid (TNF only)• RACK-1 (2.7-fold)• PEA-15 (inhibits TNF-R1-mediated Caspase 8 activity) (6.3-fold)• VDAC-1 (1.6-fold)• BOK (TNF only)• Metadherin (anti-apoptotic) (TNF only)• Gelsolin (anti-apoptotic) ( 43-fold)
Take home message????
• Vascular endothelial cells neglected in proteomics• CMEC basically no thorough study• This is novel and important study to gain knowledge into
cardiovascular disease
• Increase in oxidative stress due to TNF-α – proteins increase to counteract
• eNOS – decreased HSP90
• Cells undergo apoptosis – increase in apoptotic proteins and increase in some anti-apoptotic proteins – therefore cells are fighting back
• Due to increase in apoptotic proteins and hence increase in cell death the proteins involved in may be the result of cytoskeleton organisation which is decreased.
Quantitative proteomic analysis of HIV-1 Tat apoptosis in SH-SY5Y neuroblastoma cells
Putuma P. Gqamana1ǂ, Tariq Ganief1ǂ, Salome Smit2, Shaun Garnett1, Andrew Nel1, and Jonathan Blackburn1┴.
Quantitative proteomic analysis of HIV-1 Tat induced apoptosis in SH-SY5Y neuroblastoma cells. Manuscript in preparation.
Putuma P. Gqamana1ǂ, Tariq Ganief1ǂ, Salome Smit2, Shaun Garnett1, Andrew Nel1, and Jonathan Blackburn1┴.
Quantitative proteomic analysis of HIV-1 Tat induced apoptosis in SH-SY5Y neuroblastoma cells. Manuscript in preparation.
• Tat associated with neural cell death and probable agent of HIV associated dementia
• 2849 proteins were identified from SILAC treated cells which were either phospho-enriched or phospho-depleted (therefore reduced complexity of sample)
• 17 up regulated and 72 down regulated proteins identified from SILAC
• Dysregulation of proteins identified associated with several neurodegenerative disorders
• Cell adhesion proteins down regulated – associated with apoptosis• Proteins identified may also have role in weakening of immune response
• From results:• Tat neurotoxicity may activate early signalling via tyrosine phosphorylation receptors
and cause mitochondrial and oxidative stress leading to apoptosis. This will form basis of future biomarker discovery for HIV associated dementia
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Recent successes with Orbitrap
Orbitrap Velos
MS
Neuroblastoma cells 7539
M. smegmatis 3271
M. Bovis 2368
P. falciparum 1681
CMEC 1663
V. Cholera 1411
Urine biomarkers 1500
Sample from another MS unit 546 vs 24
Single human peptide in Arabidopsis
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Acknowledgements
Thanks to:Prof Hans Strijdom – US – CMECAnd students Amanda, Mashudu and Corli
Dr Putuma Gqamana – UCT – SILAC proteomics, neuroblastoma cellsDr Brandy Gqamana-Young – UCT – Urine proteomics
Mae Newton-Foot and Zhou Fang – US – M. SmegmatisLouise Vos – US – M. Bovis
Dr Martella du Preez and Lisa Schaeffer – CSIR – V. Cholera
Dr Cobus Zwiegelaar – Azargen – human peptide
Proteomics LaboratorySenior Analyst: Dr Salome SmitOffice: 021 938 9632Fax nr : 086 690 7602email: [email protected] van StellenboschBesoek / Visit: www.sun.ac.za/saf
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