Research Projects

Cardiovascular diseases are one of the leading causes of mortality globally and in India. Hence there is an unmet need to identify novel drug targets, which requires a broader understanding of cellular and molecular events leading to heart failure. Heart failure is mainly caused by myocardial infarction, aging, hypertension, aortic stenosis, infection, obesity, genetic predisposition, cardiotoxicity, and cancer-induced cachexia. Cancer-induced cachexia affects several organs, including skeletal and cardiac muscle, and positively correlates with mortality. Cardiac cachexia is marked by a loss in cardiac mass due to ongoing cardiomyocyte apoptosis and cardiomyocyte atrophy in patients and animal models. Despite of high clinical prevalence of cardiac cachexia, its detailed molecular mechanisms and druggable targets remain poorly explored. Gene expression alteration occurring at the transcriptional or post-transcriptional level remains the primary cause of any disease, including cardiovascular. M6A RNA methylation is one of the most prevalent dynamic reversible epigenetic post-transcriptional modifications on all kinds of RNA. M6A modification on RNA regulates its splicing, stability, and translation through m6A reader proteins. An RNA-binding protein class with a YTH domain has been shown to function as an m6A reader. Recently, some reader proteins like YTHDC1 and YTHDF2 have been shown to play a critical role in cardiac health. Here, we aim to uncover the cardiac function of YTHDF3, which remains largely unknown, by cardiomyocyte-specific knockdown in the mice. We have preliminary in vitro and in vivo data showing that AAV9 (adeno-associated virus serotype 9) mediated YTHDF3 knockdown led to cardiomyocyte apoptosis and atrophy culminating in impaired cardiac function. However, YTHDF3 is a ubiquitously expressed protein, and minor alteration in its level in other organs like the liver due to off-target delivery may indirectly affect cardiac function. Therefore, to validate the atrophic cardiac function of YTHDF3, we aim to knock down YTHDF3 specifically in cardiomyocytes using AAV9 expressing shRNAmiR (miRNA embedded shRNAs) under alpha-MHC promoter (a cardiomyocyte-specific promoter). We have already designed, synthesized, and confirmed YTHDF3 knockdown using our shRNAmiR in vivo. Like U6 promoter-driven global YTHDF3 knockdown, we hypothesize that cardiomyocyte-specific knockdown will also lead to cardiac apoptosis, atrophy, and impaired function. Localization of RNA-binding protein determines its downstream function. Our preliminary data show that YTHDF3 is localized in the nucleus of primary rat cardiomyocytes. Hence we will explore YTHDF3's role in cardiac alternative splicing and nuclear mRNA export. Similar to the atrophic phenotype upon knockdown, we have found decreased YTHDF3 levels in cancer-induced cardiac cachexia. Therefore, we aim to explore the beneficial effect of YTHDF3 overexpression in the cancer-induced cardiac cachexia model.