Atherosclerotic cardiovascular disease (CVD) is the leading cause of death in the industrialized world. Studies over the last decade suggest that failed resolution of a chronic inflammatory response is an important driving force in the progression of atherosclerosis. Accordingly, two critical unanswered questions are: (a) what are the endogenous mechanisms underlying dysregulated resolution programs in atherosclerosis and (b) what mechanism-based treatment strategies can be conceived to initiate resolution when it fails. The resolution of inflammation is regulated by specialized pro-resolving mediators (SPMs) that comprise omega-6 derived lipoxins and omega-3 derived resolvins, protectins and maresins. The overall objective of this proposal is to understand the mechanisms of dysregulated resolution in atherosclerosis and to harness SPM signaling pathways towards a novel treatment strategy. A critical enzyme in the biosynthesis of lipoxins and resolvins, 5- lipoxygenase (5-LOX) is expressed in M?s, which are abundant in atherosclerosis. This proposal is to test the hypothesis that SPM, via 5-LOX in M?s, limit progression and enhance lesion regression in atherosclerosis.
Aim 1 will explore the hypothesis 5-LOX is protective in atherosclerosis. Using chimeric Ldlr-/--5-LOX-/- mice, Sub aim I-A and B will investigate new in vivo mechanisms that underscore how 5-LOX is protective against atherosclerosis progression and regression respectively.
Aim 2 will test the hypothesis, and investigate the mechanisms therein, that the 5-LOX-derived SPM resolvin D1 (RvD1) promotes inflammation resolution and plaque stabilization in atherosclerosis. Using Ldlr-/- mice fed on a synthetic diet to induce atherosclerosis, I will investigate whether RvD1 is protective in two clinically relevant models of atherosclerosis;one that simulates aggressive lipid lowering (Sub aim II-A) and one where hyperlipidemia is intact (Sub aim II-B).
Aim 3 will explore the hypothesis the RvD1 regulates 5-LOX by controlling the balance between pro-inflammatory (e.g. leukotriene B4) and pro-resolving mediators (e.g. lipoxin A4), a key mechanism of resolution. This research will be accomplished in the setting of a comprehensive career development program designed to provide the candidate with the skills needed to become an independent scientist in cardiovascular research. During the K99/Mentored phase of the award the applicant will continue to gain expertise molecular, cellular and biochemical approaches to study the dysregulated resolution in atherosclerosis from a mechanistic standpoint. An advisory committee of established scientists/mentors in the fields of resolution, CVD and translational science will guide the candidate in her transition to scientific independence over the course of the award period.

Public Health Relevance

Cardiovascular diseases such as atherosclerotic vascular disease, is the leading cause of death in the industrialized world. Current studies suggest that failed resolution of a chronic inflammatory response is an important driving force in the progression of atherosclerosis. This project will provide a new understanding of the mechanisms that contribute to failed resolution and will provide new avenues for the treatment of atherosclerosis.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Career Transition Award (K99)
Project #
1K99HL119587-01
Application #
8566813
Study Section
Special Emphasis Panel (ZHL1-CSR-P (M2))
Program Officer
Carlson, Drew E
Project Start
2013-08-01
Project End
2015-07-31
Budget Start
2013-08-01
Budget End
2014-07-31
Support Year
1
Fiscal Year
2013
Total Cost
$108,000
Indirect Cost
$8,000
Name
Columbia University (N.Y.)
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
621889815
City
New York
State
NY
Country
United States
Zip Code
10032
Fredman, Gabrielle; Ozcan, Lale; Spolitu, Stefano et al. (2014) Resolvin D1 limits 5-lipoxygenase nuclear localization and leukotriene B4 synthesis by inhibiting a calcium-activated kinase pathway. Proc Natl Acad Sci U S A 111:14530-5
Libby, Peter; Tabas, Ira; Fredman, Gabrielle et al. (2014) Inflammation and its resolution as determinants of acute coronary syndromes. Circ Res 114:1867-79