Gene Array Study of Vulnerable Atherosclerotic Plaque

In Apo E K/O Mice Plaques Prompted to Rupture by Modified Falk ProcedureIn Human Carotid Endarterectomized PlaquesIn Human Ruptured Coronary Arteries

Morteza Naghavi, MDSadaf Anwar, MD

Mohammad Madjid, MDSilvio Litovsky, MDRahul Mitra, MD

Hugh A. McAllister, MDFrank D. Kolodgie, MDWard Casscells, MD

James T Willerson, MD

University of Texas-HoustonTexas Heart Institute

Rationales of the Study

• The basic mechanisms leading to plaque rupture in terms of genomic changes are still in shadow

• There has been no animal of plaque rupture to date• An animal model offers a great opportunity to test

new diagnostic and therapeutic approaches• Plaque vulnerability definition is at the center of

doubt and argument. Gene studies may help in clearing this issue too.

Why Going to Gene Level?

Gene

Protein

Function

Sens

itivi

ty

Why is novel about this study?

•We are going to gene level, hence having a higher probability of detecting changes of interest

•We are using our rare clone of old (>2yr) Apo E K/O mice

Of Mice and Human

• We are looking into three models of:

Apo E K/O Mice Human carotid plaquesHuman coronary plaques

Examples of Genes of Interest:

Apoptosis Lipid Metabolism

Interleukins MMPs

Thrombosis AspartateEndopeptidases

NO system MMPIs

Cell Adhesion Molecules

CysteineEndopeptidases

Nuclear factors and receptors

Cathepsins

… Serine Endopeptidases

… ….

50 Apo E K/O mice age > 2 y

• Group A 45 mice for prompting to plaque rupture

• Group B 5 mice for control

Each Five Mice:

• L-NAME (N-nitro-L-arginine methyl ester) (vasoconstriction)

• Cocaine (Hypertension, tachycardia) • Xanthine + xanthine oxidase (inflammatory response) • IL-1 beta (inflammatory response /septic shock) • Adrenaline (hypertension, tachycardia)• Methionine (direct cytotoxic effects destabilizing the

plaque) • Buthionine sulfoximine (GSH inhibition, hypertension)

Multi-Factor Approach

Cocaine + xanthine + xanthine oxidase + adrenaline

5 Mice are kept as controls with no injection

At Day Seven:

• Mice are euthenized (Co2) and then dissected

• Before day 7 Animals will be monitored every 6 hours. If any of them is found dead in the middle of the experiment it will be assessed for evidence of plaque rupture

• Choice: specialized device for cross-sectional cutting of total mouse body

• If not available: mice are dissected and atherosclerotic plaque from aortic root and arch from all mice are taken for histopathological assessment as well as mRNA study.