modulation in atherosclerotic patients August 26th, 2017, Barcelona - - PowerPoint PPT Presentation

The promise of epigenetic modulation in atherosclerotic patients

August 26th, 2017, Barcelona

Erik S Stroes Department of Vascular Medicine, AMC, Amsterdam, The Netherlands

Outline

 Atherosclerosis ‘systemic pro-inflammatory state’  Feasibility of epigenetic targeting as ‘anti-atherosclerotic’ intervention

Inflammation drives CV events

• I. Patients with CVD (risk-factors) have

increased arterial wall inflammation

Valk, Stroes, Rudd, JACC CV Imaging 2016

• II. Activation of circulating monocytes

in patients with elevated Lp(a) More transmigration in Lp(a) patients And monocytes more motile

Control Elevated Lp(a)

Valk, Stroes, Circulation 2016

• III. Activation of bone marrow

in patients up to months after CV-event

Van der Valk, Stroes, Eur Heart J 2016

Persistent increased arterial wall inflammation In CVD patients Increased progenitor potential in CVD patients

Hyperactivity of the entire inflammatory cascade

Atherosclerotic lesion, plasma cells and bone marrow

Swirski & Nahrendorf, Science 2013;339:161-6

Cantos study IL1-β antibody

August 27: Late Breaking Clinical Trials

 Canakinumab reduces CV-events in post ACS patients  Primary endpoints met:  heart attack, stroke and cardiovascular death  Thus, IL1-β inhibition combined with statins significantly reduces CV-risk in post-ACS patients with elevated CRP Balance anti-inflammatory – immune suppression ?

Outline

 Atherosclerosis ‘systemic pro-inflammatory state’  Feasibility of epigenetic targeting as ‘anti-atherosclerotic’ intervention

Why epigenetics?

Suppose you want to reduce ‘fuel use’

Scenario 1: Close down fuel switch Scenario 2: ‘Tweak’ the use

• f fuel

Wing ‘extensions’ decrease fuel use by stabilizing the airplane Very carefully

What is epigenetics?

 The study of changes in organisms caused by modification of gene expression rather than alteration of the genetic code  To ‘compare’ :  Human life = movie  DNA = script  Genetics = screen writing  Epigenetics = director

How does epigenetics work?

Change accessibility of chromatin by Among other histone modifications, allowing transcription factors to interact with regulatory regions

• Modifications to chromatin

components regulating its activity

• Modifications via addition

(writers), removal (erasers) or recognition (readers)

Epigenetics

Writing and Erasing histone ‘tails’

Neele, Eur J Pharmacol 2015

H2A H2B H3 H4 K27

methylgroup

H2A H2B H3 H4 K27 H2A H2B H3 H4 Trimethylation of histone 3 at lysine 4 (H3K4Me3): euchromatin (open) H2A H2B H3 H4 K4

 Gene transcription  Gene transcription

Trimethylation of histone 3 at lysine 27 (H3K27Me3): heterochromatin (closed)

Writers/erasers:

Histone (de)methylation

Methylation of a Lysine (K)

• pens or closes the chromatin,

depending on me1/2/3 and position:

Acetylgroup

H2A H2B H3 H4 H2A H2B H3 H4 K27

 Gene transcription

Acetylation of histone 3 at lysine 27 (H3K27Ac): euchromatin (open)

Writers/erasers

Histone (de)acetylation

Acetylation of a Lysine (K) residue opens the chromatin Hypo acetylation (less acetylgroups) closes the chromatin

Methylation/Acetylation in plaques

Plaque severity H3K9Ac + H3K27Ac +

Macrophages Lymphocytes

H3K9Ac  H3K27Ac  H3K9Ac + H3K27Ac ++ H3K9Ac + H3K27Ac 

Macrophages Lymphocytes Acetylation Methylation

H3K9Me2 ++ H3K27Me2 ++ H3K4me2 + H3K9Me2  H3K27Me2  H3K27me3 H3K4me2  H3K9Me2 ++ H3K27me2 ++ H3K4me2 + H3K9Me2  H3K27Me2  H3K4me2  Increased activating marks Decreased repressive marks

Monocyte hyperactivity in patients with elevated Lp(a)

Van der Valk, Stroes, Circulation 2016

Methylation in plasma monocytes

mediating pro-inflammatory activation

RPMI IL-6 TNFa IL-1b 40 2000 4000 6000 8000 10000 Cytokine level in pg/ml

** *

5 10 15 20 % input (H3K4me3) Lp(a) subjects Control subjects ** ** myo IL-6 TNFa

Hyperresponsiveness Of circulating monocytes

H2 A H2 B H3 H4 K4

Trimethylation of histone 3 at lysine 4 (H3K4Me3): euchromatin (open)

Nicorescu, Stroes, data on file

• Modifications via addition

(writers), removal (erasers)

• r

recognition (readers)

Epigenetics

Readers:

Bromodomains and Extra-Terminal Domain (BETs)

H2 A H2 B H3 H4 K27

BET proteins

Integral to transcription assembly

Nature Reviews Mol Cell Biology 2013;13:543-7

Decreasing BETs decreases adhesion molecule expression & monocyte adhesion

Brown, Mol Cell 2014

BET inhibition by Apabetalone

selective BD2 inhibitor

Inhibitor

Apabetalone decreases monocyte adhesion to endothelium under ‘flow’

Resverlogix, data on file

BET-inhibition attenuates polarisation and activation of ‘pro-inflammatory’ macrophages

Synthetic acetylated histone mimics block BET activity and inhibit expression of inflammatory response genes. Thus, BETi protects against inflammatory challenges

Neele A et al. Eur J Pharmacol 2015

Apabetalone (RVX-208) Reduces Atheroma in Aorta of ApoE-/- Mice

WK 8

HF Diet

WK 19 High Fat (42% kcal) Diet

Animal Arrival

Necropsy

WK 9

Chow Chow: TD 2016 +/- apabetalone

WK 33

Chow Diet

PlaceboApabetalone (150 mg/kg)

 of -40% (p<0.045)

Plaque/whole area (%) +/- SE

20 15 10 5

15.081-608-519 11.081-607-040

Whole aorta Apabetalone Placebo

16.040-776-379 8.092-895-111

Aortic sinus Whole aorta

PlaceboApabetalone (150 mg/kg)

 of -31% (p<0.016)

Aortic sinus

Jahagirdar et al, Atherosclerosis 2015

Effect of Apabetalone on cytokine expression in human PBMCs

Resverlogix, data on file

Protein Name Gene Symbol

Placebo (n=47) Apabetalone 200mg (n=47) Treatment Difference p-value vs placebo

C-reactive protein CRP

• 22.3
• 43.6
• 21.3

0.02

Tumor necrosis factor receptor superfamily TNFRSF11B

7.8

• 6.2
• 14.0

0.003

Vascular cell adhesion protein 1 VCAM1

5.7

• 6.4
• 12.2

0.005

Interleukin-6 receptor subunit alpha IL6R

• 0.1
• 9.3
• 9.1

0.01

Fibronectin FN1

• 19.8

14.3 34.1 0.04

Clinical Analysis of Vascular Inflammation in CVD Patients in ASSURE Study (n=94)

Gilham et al. Atherosclerosis 2016

The promise of epigenetics in Atheroslerosis

 Epigenetic modulation provides a means to reduce ‘redundant’ inflammation without risking immune-suppression  BET-inhibition by Apabetalone (selective BD2 inhibitor) has anti- inflammatory and anti-atherogenic effects in experimental setting  BET-inhibition by Apabetalone in patients  Reassuring safety data (>6 months)  Anti-inflammatory effect on biomarkers  Impact on CV-events?

 next presentation

Acknowledgements

 AMC, dept of vascular medicine  Fleur vd Valk  Simone Verwey  Lotte Stiekema  Renate Hoogeveen  AMC, dept of Radiology  Aart Nederveen  Hein Verberne  Funding: EU, Dutch Heart Foundation  Radboud, Nijmegen  Mihai Netea Siroon Bekkering  USCD, USA  Sam Tsimikas  Joe Witztum  International  Alberico Catapano  Borge Nordestgaard