Post-transcriptional regulation of osteoglicina by microRNA miR-155 in cardiomyocytes

Abstract

Post-transcriptional regulation of microRNA-155 by osteoglycin in cardiomyocytes. Cardiac hypertrophy is an adaptive process in response to various physiological and pathological conditions and is commonly associated with hypertension, ischemic heart disease and heart failure. The factors that contribute to the development of cardiac hypertrophy are not completely understood, however, the re-expression of fetal cardiac genes and the change in the expression of microRNAs and extracellular matrix proteins are involved with the development of this process. The cardiac extracellular matrix is an intricate network composed by structural and non-structural proteins that play important roles in homeostasis and in the remodeling process of the heart. Among the cardiac extracellular matrix proteins, the Glycoprotein Osteoglycin (OGN) has emerged as an important component in the process of cardiac remodeling. The main function of ONG is the collagen fibrillogenesis and its expression profile has been associated with the development of cardiac hypertrophy. However, the mechanisms that regulate the expression of OGN are not known. Previous bioinformatics analysis in our laboratory identified the OGN transcript as an important target of the microRNA miR-155. MicroRNAs play an important role in post-transcriptional regulation of cardiac gene expression and are emerging as important molecules in the many cardiac diseases. Recently, the microRNA miR-155 has been described as an inducer of cardiomyocytes pathologic hypertrophy its inhibition may has clinical potential for the treatment of cardiac hypertrophy and failure. Therefore, the hypothesis of this study is that OGN is regulated post-transcriptionally by mir-155 in the H9c2 cardiomyocyte hypertrophy in vitro. Discovering new molecular mechanisms that regulate cardiac hypertrophy is an important step towards the understanding of the cellular changes that occur in this process and for the development of future therapeutic strategies. (AU)