PROJECT SUMMARY/ABSTRACT
Coronary artery disease (CAD), the result of atherosclerosis formation, is the leading cause of death globally
resulting in approximately 679,000 annual deaths or the equivalent to every one in five deaths occurring in the
United States. This number is expected to increase as comorbidities of CAD diagnosed in patients continues to
rise. Currently, statins, which lowers the amount of circulating lipids, are the gold standard of preventing CAD in
patients with a concomitant diet and exercise regimen. After decades of steadily improving mortality rates, overall
trends have begun to plateau and current medications provide only modest absolute incremental benefits from
atherosclerotic plaque rupture and resultant myocardial infarction, stoke, and heart failure. Our laboratory has
previously demonstrated the G-protein coupled receptor, PAR2, is augmented in both murine and human
atherosclerotic plaques. Moreover, studies have demonstrated increased Human Antigen R (HuR) expression
at sites of vessel injury, with the potential to bind and stabilize PAR2 mRNA in these inflammatory conditions.
Though we know PAR2 contributes to the formation of atherosclerosis, the mechanism(s) in which PAR2
mediates atherosclerosis formation and the role of HuR in atherosclerosis are still unknown. Understanding the
molecular mechanisms in which PAR2 and HuR contributes to the progression of atherosclerosis could give new
insight into potential targets of therapeutics that could improve the outcomes of CAD patients and put a halt to
the diminishing returns of old therapeutics.
The primary goal of this proposal is to investigate the mechanisms by which PAR2 and HuR interact and their
contributions, both independently and dependently, to atherosclerosis development. Using data previously
collected in our lab, we know that the contributions of PAR2 in atherosclerosis derive from a non-hematopoietic
cell type, such as vascular smooth muscle cells (VSMCs). Thus, we hypothesize that activation of PAR2 in
VSMCs relocates HuR to the cytosol where it binds and stabilizes Par2 mRNA, upregulating PAR2
expression and further progressing atherosclerosis. This hypothesis will be using two specific aims and
several mouse models that consist of PAR2 and HuR genetic mutants, specifically in VSMCs (aim 1 and aim 2
respectively). We will also use a variety of in vitro experiments to observe HuR binding PAR2 mRNA (aim 2) as
well as investigate the role of PAR2 in VSMC dedifferentiation (aim 1), which recent literature has shown the
contributions of VSMC dedifferentiation to the progression of atherosclerosis. The long-term objective of this
study is to further elucidate the role of PAR2 in atherosclerosis and, if successful, will advance our knowledge of
the development and progression of this disease. These results may also positively impact the field and give
sight to potential targets to develop new therapies for CAD patients.