Reducing Plasma Cholesterol and Atherosclerosis Using miR-30c Analog C2 - TITLE: REDUCING PLASMA CHOLESTEROL AND ATHEROSCLEROSIS USING MICRORNA-30C ANALOG C2 ABSTRACT Despite the many treatment advances that have emerged in the past 75 years, cardiovascular disease (CVD) remains a major cause of global morbidity and mortality; nearly one in five individuals diagnosed with heart disease die prematurely. High plasma cholesterol levels substantially contribute to this problem. Thus, the overall goal of this proposal is to identify novel ways to reduce plasma cholesterol levels and the risk of developing atherosclerotic CVD. Our earlier findings have revealed that hepatic expression of microRNA (miR)-30c reduces plasma cholesterol and atherosclerosis in mice. Here, we provide preliminary evidence that administration of C2, a novel synthetic miR-30c analog, reduces plasma cholesterol levels in mice with diet-induced hypercholesterolemia and Ldl receptor knockout. Based on these findings, we will test the hypothesis that C2 reduces plasma cholesterol levels by limiting the production of hepatic lipoproteins without causing hepatic injury or an inflammatory/immune response. In Aim 1, we will explain the molecular mechanisms underlying the observed C2-mediated reduction in plasma cholesterol levels. First, we will test the hypothesis that C2 limits hepatic lipoprotein production by inhibiting the expression of microsomal triglyceride transfer protein. We will also test the hypothesis that C2, beyond decreasing lipoprotein production, reduces fatty acid synthesis and enhances fatty acid degradation, thereby averting hepatic lipid accumulation. We hypothesize that C2 reduces fatty acid synthesis by downregulating Elovl5 and Elovl6. In addition, we will evaluate the role of newly identified genes in fatty acid degradation, whose expression is upregulated in C2 expressing livers. In Aim 2, we hypothesize that C2, given its unique mode of action, will act additively with other lipid-lowering drugs in reducing plasma cholesterol and atherosclerosis. We will determine whether C2 functions additively with statins and ezetimibe in reducing plasma cholesterol and limiting atherosclerosis progression. Second, we will determine whether administration of C2 plus apoC3 inhibitors that lower plasma lipids by enhancing lipoprotein lipase activity additively reduces plasma cholesterol, by performing studies in apoC3 knockout mice. Third, we will test whether C2 reduces lipid levels when co-administered with GLP-1 agonists, which moderately lower plasma lipids but are excellent drugs for diabetes and obesity treatment. In Aim 3, we will test the hypothesis that C2 lowers plasma cholesterol levels in non-human primates maintained on a Western-style diet. We will determine whether C2 decreases diet-induced hypercholesterolemia by reducing hepatic lipoprotein production in these non-human primates. We anticipate that the combined results of these studies will provide convincing support for future human clinical trials of C2 as a first-in-class miR-based therapeutic that reduces plasma cholesterol levels without causing hepatic injury or inflammation.
