Análise de biomarcadores da matriz extracelular do coração de camundongos tratados com isoproterenol

Abstract

Hypertension is associated with high morbidity and mortality rates in the world population. High levels of blood pressure produce intense stress tissue, a progressive condition for the development of cardiac hypertrophy, which affects the efficiency of the heart. The existing biomarkers to predict myocardial lesions are not able to show other harmful consequences resulting from pathological processes such as hypertrophy, ischemia and inflammation, and therefore identification of markers that are more specific to the conditions studied is required. In order to find such markers that may indicate a cardiac hypertrophy situation, we used mice model for this condition which had received isoproterenol. In this model, the myocytes from those mices were induced to apoptosis, and fibroblasts had increased collagen production and extracellular matrix proteins deposition, so modifying protein profile. We used a procedure called decellurarization to determina protein profile. This procedure leads to an enrichment of protein contents by removing cell content and its nuclear remnants, while maintaining matrix integrity. After the enrichment procedure, phage display technique was used to determine the diversity of peptide present in hypertrophic cardiac tissue. Our results demonstrated that cardiac hypertrophy due to an increase in heart weight compared to the body weight and tibia´s length, as well as changes in heart rate and blood pressure were consistent with the administration of isoproterenol. The decellularization process had its efficiency demonstrated by the minimal amount of DNA content present in tissue and by browsing through histology and electron microscopy of cell integrity devoid of matrix content. After 3 rounds of selection using phage display technique specific peptides were identified in the hypertrophic heart muscle matrix. Then, we have obtained the DNA sequencing of those peptides which were expressed on phage surface. This approach opens up prospects for the discovery of markers that can predict the development of the pathological condition of hypertrophy.