Developing Long Noncoding RNA Therapy for Precision Cardiac Repair

PROJECT SUMMARY Heart disease is the leading cause of death in the United States. About 875,000 Americans die from heart disease each year, of which 50-60% deaths are caused by coronary artery disease (CAD). CAD, the most common type of heart disease, can lead to heart attack and sudden death. While the survival patients can progress into chronic cardiomyopathy and heart failure (HF) that is featured with myocardial fibrosis. Myocardial fibrosis is associated with adverse outcomes. Currently, there is no specific drugs for cardiac fibrosis. Stem cell or exosome therapy has been a promising option for fibrotic disease. However, the challenges in quality control and GMP-grade large-scale production as well as the elusive mechanisms have hindered the translational application. One solution to address the challenges is to identify specific molecules that underlie the antifibrotic mechanisms of exosomes, and design nanoparticle carriers to deliver them. In our preliminary studies that form the basis of proposal, we found that transcription factor Tcf21 is crucial in suppressing myofibroblast activation, and exosome cargo long noncoding RNA (lncRNA)-TARID played as the upstream enhancer of Tcf21 gene expression. Recently, the application of lipid nanoparticles (LNPs) has expanded in a large scope of clinical trials for nucleic acid delivery. In this proposal, we aim to develop lncRNA LNP for treatment of cardiac fibrosis. The overarching hypothesis is that LNPs loaded with lncRNA-TARID (LNP-TARID) can upregulate Tcf21 to suppress myocardial fibrosis and improve cardiac functions. Our original grant focuses on microRNA cargos in the exosomes, such as miR-21 and miR-146. From the sequencing experiments, we serendipitously encountered other non-coding RNAs in the exosomes that play an essential role in cardiac repair. LncRNA TARID is one of them. Our preliminary studies confirmed the therapeutic role of LncRNA TARID in cardiac fibrosis. Our renewal submission will be focusing on this RNA agent, using LNP as the delivery carrier. Aim 1: Optimization of LNP-TARID formulations and in vitro characterization; toxicity studies in naïve animals. Aim 2: Determine the safety and efficacy of LNP-TARID treatment in mouse models of acute and chronic MI. Aim 3: Translate the LNP-TARID therapy into a clinically-relevant pig model of cardiac I/R injury. Our proposal is both mechanism-driven and product-oriented. The results from our research will pave the ground for the development of new non-coding RNA therapies to treat myocardial infarction and help us gain mechanistic insights on the Tcf21-regulated cardiac fibrosis pathways.