Expression profile of genes involved in Unfolded Protein Response in heart muscle of rats submitted to aerobic exercise training

• Grant number: 12/08396-8
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): August 01, 2012
• Effective date (End): July 31, 2013
• Field of knowledge: Biological Sciences - Physiology - Physiology of Organs and Systems
• Principal researcher: Paulo Rizzo Ramires
• Grantee: Amanda Corrêa Wirgues
• Home Institution: Escola de Educação Física e Esporte (EEFE). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The endoplasmic reticulum (ER) is an organelle present in eukaryotic cells, which participates in numerous intracellular processes. Some of major ER functions are calcium (Ca+2) storage, synthesis of lipids and steroids and protein folding. However, ER homeostasis disruption leads to Ca+2 imbalance and an accumulation of unfolded proteins in the lumen of the ER. The responses are collectively known as ER stress sand are associated with prolonged cardiac dysfunction, which contributes to the establishment of cardiovascular diseases. In an attempt to reestablish normal ER function and cellular homeostasis, a compensatory response, known as the Unfolded Protein Response (UPR) by activating transcription factors and inhibiting the synthesis of new polypeptide chains, until the ER homeostasis is restored in cardio myocytes. Aerobic exercise training (AET) has been prescribed for improving cardiovascular health. We have previously demonstrated that AET improves the net balance of proteins involved in intracellular cardiac Ca+2 handling in healthy and heart failure rodents, which suggests that AET may play an important role in cardiac ER homeostasis. However, little is known about the impact of AET on ER UPR activation. Therefore, the present study aims to evaluate the impact of AET on mRNA levels of UPR components in rat cardiac muscle. (AU)