Inflammation involvement in the hypertrophic response of the skeletal muscle in Type I Diabetic rats

• Grant number: 19/19097-0
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Effective date (Start): December 01, 2019
• Effective date (End): February 28, 2023
• Field of knowledge: Biological Sciences - Physiology - General Physiology
• Principal Investigator: Rui Curi
• Grantee: Maria Vitoria Martins Scervino
• Host Institution: Centro de Ciências Biológicas e da Saúde. Universidade Cruzeiro do Sul (UNICSUL). São Paulo , SP, Brazil

Abstract

Skeletal muscle overload triggers an inflammatory process that modulates tissue repair and remodeling, promoting muscle hypertrophy. Patients with Type 1 Diabetes Mellitus (T1DM) have severe loss of muscle mass and strength. However, when subjected to mechanical overload, skeletal muscle of diabetic animals exhibits hypertrophy in the same magnitude as control animals. Inflammation is a crucial step in the muscle hypertrophy process and hyperglycemia is closely associated with increased expression of inflammatory markers and this may be a way to facilitate muscle hypertrophy and to compensate for the lack of insulin. We will evaluate the inflammatory response, regeneration and remodeling mechanisms after seven days of overload in muscles with predominance of glycolytic (long digital extensor - EDL) and oxidative (soleus) fibers, concomitantly with the establishment of streptozotocin - induced diabetic state in rats. The following measurements will be performed: gene and protein expression of pro and anti-inflammatory cytokines, presence of leukocyte infiltrates in muscle tissue, pattern of activation of satellite cells, abundance of collagen fibers of types I and II, and expression of growth factors. The hypothesis to be tested is that the pre-existing inflammation in skeletal muscle may favor muscle hypertrophy in the diabetic condition. (AU)