Abstract
Diabetes Mellitus (DM) is a metabolic disorder of high prevalence in the world, responsible for numerous co-morbidities, generating costly expenditures on health systems. Recently, pivotal role was attributed to the benefits of physical exercise for the prevention and/or treatment of DM, especially involving the improvement of glucose uptake in skeletal muscle, however, the molecular mechanisms involved in this process are still obscure. Recently, a new element appears in the pathophysiology of DM, which has received high importance: it is a group of small RNAs that do not encode proteins, but contribute to alterations in the expression of genes, called microRNAs (miRNAs). MiRNAs generally inhibit protein translation, and can affect the stability of mRNAs. Its effects have been observed in several cellular dysfunctions related to insulin secretion and glucose homeostasis, and consequently the development of DM. As far we know, no study has evaluated the influence of exercise on the expression of these miRNAs in muscle tissue of diabetic or non-diabetics animals. Therefore, the objectives of this study are: to investigate the expression of miR-1, miR-133a, miR-133b and miR-206 in skeletal muscle of diabetic rats and controls, as well as studying the effect of muscle contraction in vitro on expression of these miRNAs, and investigate the possible correlation between the variations of miRNAs and the expression of glucose transporter GLUT4 in skeletal muscle. It is expected that the results will help to understand the effects of muscle contraction on GLUT4 expression, generating new prospects for inducing increased GLUT4, improving the capacity of glucose utilization in muscle from diabetes bearers.
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