Analysis of Metalloproteinases and Their Inhibitors in Chagas disease cardiomyopathy: Role of miRNAs in its Post-Transcriptional Regulation

Abstract

The Chagas disease cardiomyopathy (CCC) is an inflammatory dilated cardiomyopathy characterized by an intense cardiac remodeling, hypertrophy, fibrosis and a myocarditis rich in macrophages and T cells. This affects 20-40% of patients infected with Trypanosoma cruzi (T. cruzi). To date, there are no markers to identify the population at risk for the development of CCC, and the survival of patients is shorter than that of patients with dilated heart of no inflammatory etiology. The process of cardiac remodeling is characterized by the restructuring of the extracellular matrix (ECM) which is mediated largely by enzymes from the endoproteinases group called matrix metalloproteinases (MMPs) and its specific inhibitors (TIMPs). 25 MMPs have been described in humans where modification of their expression and /or activity correlates to various pathological conditions including cardiovascular diseases. MMPs and TIMPs may have its expression regulated post-transcriptionally by microRNAs. These are small RNA molecules of 22 nucleotides that bind to complementary sequences present in specific mRNA 3' untranslated regions (3'UTR) called target, leading to cleavage of the latter and inhibition of translation, resulting in silencing of gene expression. The aim of this project is to evaluate the role of MMPs and TIMPs during Chagas' disease, in myocardium samples of patients with CCC. We will evaluate the expression of major MMPs and TIMPs by Real Time PCR, Western blotting, and immunohistochemistry as well study its proteolytic activity by zymography and for TIMPs, reverse zymography. After we select the main MMPs and TIMPs with their expression and/or activity altered we will analyze which miRNAs can act as regulatory elements of their expression and have an inverse expression pattern compared to that observed for MMPs and/or TIMPs. The results generated by the present work will contribute to elucidate the role of miRNAs, MMPs and TIMPs expression during CCC, allowing us to develop in the future new diagnostic tools, prognostic and therapeutic approaches to improve the quality of life of patients with CCC.