Research Article: Aerobic exercise training prevents obesity and insulin resistance independent of the renin angiotensin system modulation in the subcutaneous white adipose tissue

Date Published: April 25, 2019

Publisher: Public Library of Science

Author(s): Anna Laura V. Américo, Cynthia R. Muller, Bruno Vecchiatto, Luiz Felipe Martucci, Miriam H. Fonseca-Alaniz, Fabiana S. Evangelista, Michael Bader.

http://doi.org/10.1371/journal.pone.0215896

Abstract

We investigate the effects of aerobic exercise training (AET) on the thermogenic response, substrate metabolism and renin angiotensin system (RAS) in the subcutaneous white adipose tissue (SC-WAT) of mice fed cafeteria diet (CAF). Male C57BL/6J mice were assigned into groups CHOW-SED (chow diet, sedentary; n = 10), CHOW-TR (chow diet, trained; n = 10), CAF-SED (CAF, sedentary; n = 10) and CAF-TR (CAF, trained; n = 10). AET consisted in running sessions of 60 min at 60% of maximal speed, five days per week for eight weeks. The CAF-SED group showed higher body weight and adiposity, glucose intolerance and insulin resistance (IR), while AET prevented such damages in CAF-TR group. AET reduced the p-AKT/t-AKT ratio and increased ATGL expression in CHOW-TR and CAF-TR groups and increased t-HSL and p-HSL/t-HSL ratio in CAF-TR. AET prevented adipocyte hypertrophy in CAF-TR group and increased UCP-1 protein expression only in CHOW-TR. Serum ACE2 increased in CHOW-TR and CAF-TR groups, and Ang (1–7) increased in the CHOW-TR group. In the SC-WAT, CAF-TR group increased the expression of AT1, AT2 and Mas receptors, whereas CHOW-TR increased Ang (1–7) and Ang (1–7)/Ang II ratio in SC-WAT. No changes were observed in ACE and Ang II. Positive correlations were observed between UCP-1 and kITT (r = 0.6), between UCP-1 and Ang (1–7) concentration (r = 0.6), and between UCP-1 and Ang (1–7)/Ang II ratio (r = 0.7). In conclusion, the AET prevented obesity and IR, reduced insulin signaling proteins and increased lipolysis signaling proteins in the SC-WAT. In addition, the CAF diet precludes the AET-induced thermogenic response and the partial modulation of the RAS suggests that the protective effect of AET against obesity and IR could not be associated with SC-WAT RAS.

Partial Text

Aerobic exercise training (AET) has been widely used for the prevention and treatment of obesity, insulin resistance (IR) and type 2 diabetes (T2D) because it is able to improve mitochondrial function and fatty acid oxidation [1, 2], reduces body weight and adiposity [3, 4], improves insulin sensitivity and glucose uptake in the skeletal muscle [5]. AET also prevents ectopic lipid accumulation [6, 7] and ameliorates inflammatory response in T2D patient [8].

The present study proposed to investigate the effects of AET on the thermogenic response, substrate metabolism and RAS in the WAT-SC of mice fed cafeteria diet. For this, we firstly tested the efficacy of the AET to promote aerobic adaptation through a maximal physical test after AET. According to the results it was observed the favorable adaptation to AET in both trained groups. This result corroborates previously studies published in the literature [3, 7, 50]. It is already known in the literature that the improvement in the physical performance of trained animals establishes a direct relation between the improvement of the aerobic capacity and reduction of the risk of cardiovascular and metabolic diseases [55, 56].

In conclusion, the AET prevented obesity and IR, reduced insulin signaling proteins and increased lipolysis signaling proteins in the SC-WAT. In addition, the CAF diet precludes the AET-induced thermogenic response and the partial modulation of the RAS suggests that the protective effect of AET against obesity and IR could not be associated with SC-WAT RAS.

 

Source:

http://doi.org/10.1371/journal.pone.0215896

 

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