Assessment of the anti-inflammatory effects of endurance training in adipose tissue: the possible mediating role of adiponectin

Abstract

Obesity is considered one of the major causes of mortality and morbidity worldwide, as well as, a public health concern. Nowadays, adipose tissue is considered an endocrine organ due its ability to produce cytokines, such as interleukins (IL), tumor necrosis factor-± (TNF-±), adiponectin, among others. Epidemiological studies have been shown that increased adipose tissue can augment the production of pro-inflammatory cytokines (low-grade chronic inflammation [LGCI]), which are associated with several comorbidities. Therefore, since aerobic exercise can decrease LGCI, this exercise has been reported as a great way to treatment this outcome. Another plausible hypothesis is that aerobic training can increase, both acute and chronic, the levels of adiponectin. Adiponectin, produced mainly by subcutaneous adipose tissue, has been widely studied regarding its anti-inflammatory effects, as the suppression of Toll-like receptor (TLR-4) pathway, which reduces the production of pro-inflammatory cytokines (interferon-³, IL-6, IL-1² e TNF-±). Moreover, adiponectina can augment the expression of anti-inflammatory cytokines such as IL-10 and IL-1ra via another pathway. These effects were observed in immune cells and adipocytes, showing this adipokine can be involved in the anti-inflammatory effects of aerobic training. Given that aerobic exercise can increase adiponectin concentrations and this one exerts an anti-inflammatory role in adipose tissue, the aim of the present study will be investigate if the anti-inflammatory effects of aerobic exercise in adipose tissue occur in an adiponectin-mediated pathway.We will use C57BL/6 and adiponectin knockout (Adiponectin-/- [AdipoKO]) mice aged 4 to 6 week. Firstly, we will analyze what exercise intensity (60% and 85% VO2max) is better to promote anti-inflammatory effects in adipose tissue. After, both types of animals will be divided into the following groups: 1) control (balanced diet); 2) high fat diet (HFD) and; 3) HFD plus aerobic training (12 weeks). At this moment, we will evaluate in the plasma and adipose tissue the metabolic and inflammatory profile before and after interventions. If adiponectin is required for the anti-inflammatory effects of exercise, we will transplant the subcutaneous adipose tissue of C57B/6 to AdipoKO aiming to verify whether the disorders caused by the absence of adiponectin are reversed. (AU)