demystifying medicine 2016 · 2016-05-04 · 0.8 grams of plant sterols in three slices 0.4 grams...

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