Senior Staff Clinician Lipid Service, Cardiovascular and Pulmonary Branch
National Heart, Lung, and Blood Institute, NIH
Robert D. Shamburek, MD
Demystifying Medicine 2016 May 3, 2016
Cholesterol: Too Much and Too Little are Bad for Your Health
Robert D. Shamburek, M.D
No Relevant Financial Relationships with
Commercial Interests
Disclosures
Heart Attack Pancreatitis
High Cholesterol
TC > 250 mg/dL
High Triglyceride
Trig > 1,500 mg/dL
What is a “healthy person” in the U.S.? The incidence of obesity in the U.S. population has increased greatly over the last decades resulting in development of multiple risk factors for CAD. What has happened to David?
The “Average” Person
David
Sculpted by Michelangelo from 1501 to 1504 Articles.mercola.com/sites/articles/archive/2
1504
What has happened to David? Quit exercising (no more marathons)
Gave up Mediterranean diet High fat/carbohydrate diet (Junk food)
Drank excessive alcohol Gained weight
David
Sculpted by Michelangelo from 1501 to 1504 Articles.mercola.com/sites/articles/archive/2
Metabolic Syndrome
1504 2016
www.speakforchange.org
Tabitha has picked up his bad habits
Diet and lifestyle play an important role in obesity and in atherosclerosis.
Development of Atherosclerotic Plaques
Normal
Fatty streak
Foam cells
Lipid-rich plaque
Lipid core
Fibrous cap
Thrombus
Circulation, 104 (3):365–372.
Development of Atherosclerosis
Years 30 35 40 45 50 55 60
Atherosclerosis takes years or even decades to occur.
Circulation, 104 (3):365–372.
Development of Atherosclerosis
Clinical Trial
Regression Progression
Secondary Prevention
High Cholesterol Low Cholesterol
Familial Hypercholesterolemia (FH) TC = 1,000 mg/dL
Abetalipoproteinemia TC = 30 mg/dL
Genetic Causes
What is the role of lipoproteins (LDL, HDL) in lipid metabolism and atherosclerosis? Atherosclerosis can occur with high LDL or with low HDL.
Oil in Water
Triglyceride in Plasma
Triglyceride = Energy
Cholesterol = Membrane stabilizer
Lipoprotein e.g. LDL, HDL
Triglyceride Free Cholesterol (FC)
Cholesteryl ester (CE)
mature HDL
nascent HDL
LCAT (Lecithin Cholesterol Acyltransferase)
Cholesterol Ester
“Lecithin”
“Acyl”
CE
FC
Alpha Spherical HDL Pre-beta Discoidal HDL
HDL Structure
Delipidated apoAI Pre-beta Disc Alpha Spherical HDL
Apo AI
5% 95%
Free chol. CE
Overview of Plasma Lipid Metabolism
Blood, Vol. 89, Issue 6, 1886-1895, March 15, 1997
Exogenous Pathway “food”
Endogenous Pathway “fasting”
Reverse Cholesterol Transport
TG
Chol
TG
Fasting Lipid Profile
Total cholesterol 270
LDL (direct or calculated*) “bad” 175
HDL “good” 31
Triglyceride 320
* Triglyceride <400 mg/dL
Friedewald equation Total cholesterol = * LDL + HDL + VLDL (Trig/5)
* LDL = Total cholesterol – HDL – (Trig / 5)
Lipemic Plasma - Hypertriglyceridemia
Cream (chylomicron)
Turbid (VLDL)
intestine
liver
Present in Non fasting sample
Lipoprotein Isolated by Electrophoresis (Charge) and Density
VLDL LDL HDL Chylo
Charge
Density
LIPOPROTEIN SUBFRACTIONS D
en
sity
g/m
L
Diameter Å (Angstroms)
B
E
B
E
B
E B
E
B E
B
Chylomicron VLDL
B
B
B
LDL
HDL
A A
A
A
A
2a
IDL2
IDL1
I
IVa
IIIa
IVb IIIb
IIb
2b
3a
3b
3c
1.140
1.100
1.060
1.020
1.006
0.095
60 100 140 200 280 400 600 800 1000
LIPOPROTEIN SUBFRACTIONS D
en
sity
g/m
L
Diameter Å (Angstroms)
B
E
B
E
B
E B
E
B E
B
Chylomicron VLDL
B
B
B
LDL
HDL
A A
A
A
A
2a
IDL2
IDL1
I
IVa
IIIa
IVb IIIb
IIb
2b
3a
3b
3c
1.140
1.100
1.060
1.020
1.006
0.095
60 100 140 200 280 400 600 800 1000
Lipid Methyl Group Signal From Isolated Subclasses
Clin Lab Med 26:847-70, 2006
LDL-c LDL-c
LDL particle # 800 LDL particle # 1,400
LDL particle # 1,000 normal
Normal Ranges (10th-90th percentile) for NMR LipoProfile Parameters
Clin Lab Med 26:847-70, 2006
HDL LDL VLDL Chylo IDL
Triglyceride Muscle, adipose
ApoB
Triglyceride 400, TC 400
Triglyceride 8000, TC 400
Triglyceride 100, TC 400
Triglyceride 400, TC 400
Triglyceride 8000, TC 400
Triglyceride 100, TC 400
Increased VLDL
TRIGLYCERIDE METABOLISM IN
FAMILIAL HYPERCHYLOMICRONEMIA
VLDL Triglyceride
Chylomicron Trig
Monoglycerides
+
Diglycerides
+
Free Fatty Acids
LPL
ApoC-II
Unspun Lipemic Plasma
Normal plasma
Severe hypertriglyceridemia
CHYLOMICRONEMIA SYNDROME
(Type I Hyperlipoproteinemia)
Clinical features Lipemic plasma, lipemia retinalis
eruptive xanthomas and
recurrent pancreatitis
Lipoprotein phenotype Type I phenotype
Plasma lipids and
lipoproteins
Elevated plasma triglycerides
chylomicrons, and VLDL (5000 mg/dl)
Plasma apolipoproteins Kindreds with LPL or apoC-II
deficiency
Metabolic defect Delayed clearance of triglyceride-
rich lipoproteins
Pancreatitis in Children
High Triglyceride
Trig > 5,000 mg/dL
www.skinsite.com
Eruptive Xanthoma
Lipemia retinalis
Retina 25:,803-804, 2005
Does anyone here work with the apoE knockout mouse (apoE KO) as a model of atherosclerosis?
Triglyceride 400, TC 400
Triglyceride 8000, TC 400
Triglyceride 100, TC 400
Increased IDL
112 158
ApoE3 NH2 Cys Arg COOH
ApoE2 NH2 Cys Cys COOH
ApoE4 NH2 Arg Arg COOH
ApoE ISOFORMS a
Palmar Xanthoma
www.gfmer.ch/genetic_diseases_v2/gendis_detai
Palmar Xanthoma
Tuberous Xanthoma
www.gfmer.ch/genetic_diseases_v2/gendis_detai
Heart Attack (30-40’s)
TC 400 mg/dL and Triglyceride 400 mg/dL
Dysbetalipoproteinemia
Clinical features Palmar and tuberous xanthomas,
xanthelasma, and premature
cardiovascular disease
Lipoprotein phenotype Type III phenotype
Plasma lipids and
lipoproteins
Elevated plasma cholesterol,
triglycerides, VLDL, and IDL
Plasma apolipoproteins Kindreds with apoE deficiency
or apoE2E2
Metabolic defect Delayed clearance of remnants
of triglyceride rich lipoproteins
Triglyceride 400, TC 400
Triglyceride 8000, TC 400
Triglyceride 100, TC 400
Increased LDL
Arcus
http://www.cholesterolcholestrol.com/high-cholesterol-cholestrol-symptoms.html
Xanthelasma
Tuberous Xanthomas
Tendon Xanthoma
www.bmj.com www.studyblue.com
Achilles Tendon
Heart Attack (30-40’s)
High Cholesterol
TC 400 mg/dL and Triglyceride 100 mg/dL (LDL 350 mg/dL)
We have reviewed the disorders that increase the deposition of cholesterol on the arteries.
What removes the cholesterol from arteries?
deposit
remove
LDL
IDL Triglyceride remnants
HDL
Triglyceride
Cholesterol
Muscle, adipose
ApoB
mature HDL
nascent HDL
LCAT (Lecithin Cholesterol Acyltransferase)
Cholesterol Ester
“Lecithin”
“Acyl”
CE
FC
75%
25%
Step 2 Step 1
The defect in the first step of
Reverse Cholesterol Transport (RCT) is ABCA1 (Tangier Disease)
HDL <1
X
Tangier Island, Chesapeake Bay Dr. Don Fredrickson, NIH
Orange tonsils
TANGIER DISEASE
Clinical Features Orange tonsils, cloudy cornea
splenomegaly, intermittent
neuropathy, and premature CAD
Plasma Lipids and
Lipoproteins
HDL < 5 mg/dL, LDL low
and hypertriglyceridemia
Metabolic Defect Rapid clearance of plasma
HDL and apoAI
Genetic Defect Defect in ABCA1 transporter
Plasma Apolipoproteins Decreased apoAI
ABCA1
The defect in the second step of
Reverse Cholesterol Transport (RCT) Is LCAT deficiency
HDL <1
X
Lp X particle Kidney damage
CE
LCAT DEFICIENCY
Clinical Features Cloudy cornea (fisheye)
Renal disease
No premature CAD
Plasma Lipids and
Lipoproteins
HDL < 5 mg/dL, LDL low
hypertriglyceridemia, and
Lp X particle
Metabolic Defect Rapid clearance of plasma HDL
and apoAI
Genetic Defect Defect in LCAT enzyme (Lecithin:cholesterol acyltransferase)
Plasma Apolipoproteins Decreased apoAI
“Fish eye”
Anemia
Target cells
Proteinuria
Renal failure (BUN, Creatinine)
Dialysis Kidney transplant
Familial Lecithin:Cholesterol Acyltransferase Deficiency: First-in-Human Treatment with Enzyme Replacement
J Clin Lipid 10:356-367 , 2016
Lipoproteins and Lipids During Dose Optimization Phase
J Clin Lipid 10:356-367 , 2016
Baseline 18%
FPLC Analysis of Plasma Lipids Before and 24 Hours After rhLCAT Infusion
J Clin Lipid 10:356-67 , 2016
LCAT Deficiency
Normal
No HDL LpX
HDL No LpX
Lipoproteins and Lipids during Optimization (OPT) and Maintenance Phases
J Clin Lipid 10:356-367 , 2016
Baseline 18%
OPT Main. Phase Main. Phase
Maintained Increased Cholesterol Esters
Day Post Infusion
0 20 40 60 802
4
6
8
0
50
100
150
200
Dose
Optimization
0.9 9.0
3.0
9 mg/kg
Maintenance
Day of Study
sC
r m
g/d
l
CysC
mg
/LB
UN
mg
/dL
Effect Cr, Cystatin C and BUN
Stabilized or improved renal function. J Clin Lipid 10:356-367 , 2016
22
24
26
28
30
32
0 10 20 30 40 50 60 70 80 90
8
8.5
9
9.5
10
10.5
11
Effect of rhLCAT on HCT and Hemoglobin g
/dL
Pe
rce
nt
-5
0
5
10
15
20
25
30
0 10 20 30 40 50 60 70 80 90
Day on Study Day on Study
Hemoglobin (nl >13.7)
Hematocrit (nl > 40%)
Percent Change From Study Start
Perc
ent
Ch
ange
↑25%
↑25%
ICU
J Clin Lipid 10:356-367 , 2016
ACP-501 was well-tolerated with lipid changes that are consistent with increased HDL maturation. Improvements in renal and hematological biomarkers in this patient support continued development of ACP-501 as enzyme replacement therapy for FLD.
Conclusions
Two Classical Intestinal and Liver Disorders Leading to Lipids Disorders
Lipoprotein Metabolism – ApoB Lipoproteins
TC 40, HDL 35, LDL 0, Triglyceride 0
X
X
Abetalipoproteinemia – MTTP gene
ABETALIPOPROTEINEMIA
Clinical features
Fat malabsorption, spinocerebellar ataxia, acanthocytosis and
atypical retinitis pigmentosa.
Plasma lipids and lipoproteins
Hypocholesterolemia, absence of chylomicrons, VLDL, and LDL.
HDL only plasma lipoprotein, LDL 0, Triglyceride 0
(heterozygotes have normal plasma lipoproteins).
Plasma apolipoproteins
Deficiency of plasma apoB-48 and apoB-100.
Metabolic defect
Marked reduction in secretion of intestinal chylomicrons and liver
VLDL. Fat soluble vitamin deficiency – vitamin E & A
Genetic Defect
Defect in MTTP – microsomal triglyceride transfer protein
Liver - VLDL Secretion
Shelness: Curr Opin Lipidol, Volume 12(2).April 2001.151-157
ApoB
MTP
Vitamin E & A
*
* *
Vitamin E & A
Intestinal
Acanthocyte
Normal Intestinal cell
Fat in Intestinal cell
Neurological Deterioration
Abetalipoproteinemia TC = 30 mg/dL and Triglyceride 0 mg/dL
Spinocerebellar ataxia
“Vitamin E deficiency”
Peripheral bony spicules
Attenuated vessels
Macular scarring / atrophy Optic nerve head pallor
Atypical Retinitis Pigmentosa
“Vitamin A deficiency”
Lipoprotein Metabolism – ApoB Lipoproteins
TC 450, HDL 35, LDL 400
X
X
Sitosterolemia – ABCG5 / ABCG8 gene
Cholesterol (animal) Sitosterol (plant)
Sterols
Egg Seed
Animal
Plant
SITOSTEROLEMIA
Clinical Features Arcus, tendon xanthomas, and
premature cardiovascular disease
and arthritis
Lipoprotein Phenotype “Pseudo FH”
Plasma Lipids and
Lipoproteins
Elevated plasma cholesterol
and LDL
Elevated plant sterols (sitosterol)
Plasma Apolipoproteins Increased plasma apoB
Metabolic Defect Hyperabsorption of intestinal
sitosterol and delayed biliary excretion
Genetic Defect Defect on ABCG5 and ABCG8
NPC1L1
Sitosterol
NPC1L1
NPC1L1
NPC1L1
How does dietary sitostanol work to lower cholesterol?
Ann Rev Phys 69:221-248, 2007
Intestinal Absorption of Sterols
Ann Rev Phys 69:221-248, 2007
Intestinal Absorption of Sterols
Chol
Chol
Chol
Chol
Chol
Chol
Chol
Chol
Chol
Sito
Sito
Chol
Sito
Chol
Chol
Chol
Sito
Sito Chol
Ann Rev Phys 69:221-248, 2007
Intestinal Absorption of Sterols
Sito
Sito
Sito
Sito
Sito
Sito
Sito
Sito
Sito
Chol
Chol
Sito
Sito
Sito
↓Chol Chol
Benecol
Malabsorbed
2-8%
0.85 grams of plant stanol esters per serving (1 tablespoon )
2 grams of plant sterols per serving (100 ml)
0.4 grams of plant sterols per serving ( 8 fluid ou)nce
Low-fat extra-sharp Cheddar,
Monterey jack and mozzarella
0.65 grams of "phytosterol esters" per serving (1 ounce)
Sitostanol at the Grocery Store
Benecol spread margarine Promise activ Supershots
Minute Maid Heart Wise
Whole grain and oat with CoraWise Nature Valley Healthy Heart granola bars
0.4 grams of plant sterols per bar 0.8 grams of plant sterols in three slices
Dark- and milk-chocolate-covered
almonds and raisins, and bars
1.1 to 1.5 grams of sterols per serving (1-ounce package)
Dark chocolate with pomegranate muffins
0.4 grams of plant sterols per serving (one 2-oz muffin)
Sitostanol at the Grocery Store
1.8 grams of plant sterols per tablet 2.1 grams of plant sterols per tablet
Sitostanol at the Pharmacy
The $15,000 question?
PCSK9 inhibitor
Proprotein convertase subtilisin/kexin type 9
LDL 30, 90 or 200 mg/dL
PCSK9 With the Location of Naturally Occurring
Mutations Associated with Elevated (top) or
Reduced (bottom) Plasma Levels of LDL-C
Curr Atheroscler Rep (2010) 12:308–315
JM McKenney. Late-Breaking Clinical Trials ACC 3/26/12
Plasma
JM McKenney. Late-Breaking Clinical Trials ACC 3/26/12
LDLr Destroyed
JM McKenney. Late-Breaking Clinical Trials ACC 3/26/12
Plasma Antibodies
PCSK9 Inhibitors
Praluent (alirocumab) Sanofi/Regeneron 75 -150 mg administered SQ once every 2 weeks
Repatha (evolocumab) Amgen 150 mg administered SQ once every 2 weeks
$14,000 - 15,000 / year
Mechanisms of LDL-Lowering Therapies
Cell Met 23:405-412, 2016
Proteins Regulating Lipoprotein Lipase Activity Are Therapeutic Targets
ApoC-III, ANGPTL3, and ANGPTL4 are all inhibitors of LPL activity and thus candidates for therapeutic inhibition. ApoA-V is a stimulator of LPL activity and thus a candidate for upregulation or augmenting its activity. Cell Met 23:405-412, 2016
Muscle
CII
Novel Therapies for Severe Dyslipidemia Originating from Human Genetics
Curr Opin Lipid 2:112-124, 2016
Clinical Researcher Basic Scientist
Clinical Researcher Basic Scientist
Post Docs & Fellows
Acknowledgements
NIH
Alan Remaley
Marcelo Amar
Lita Freeman
AlphaCore Pharma
Bruce Auerbach
Becky Bakker-Arkema
Brian Krause
Reyn Homan
Virginia Commonwealth Univ.
Charles Schwartz
AstraZenica /MedImmune
Sotiros Karathanasis Edward Piper
Michael McCarthy
Christina Rondinone
The Patients
Acknowledgements NIH others Ed Neufeld Maureen Sampson Boris Vaisman John Stonik Steve Demosky Scott Gordon
Tufts University Ernie Schaefer Bela Asztalos NIH Investigative Pharmacy Judy Starling Hope Decederfelt
5NW Metabolic Ward Diane McCluskey Nora Quade Raven McGlotten Pamela Orzechowski Pacific Biomarkers
