Adipose tissue plasticity mediated by the counterregulatory axis of the renin-angiotensin system: Role of Mas and MrgD receptors.

The renin-angiotensin system (RAS) is an endocrine system composed of two main axes: the classical and the counterregulatory, very often displaying opposing effects. The classical axis, primarily mediated by angiotensin receptors type 1 (AT1R), is linked to obesity-associated metabolic effects. On the other hand, the counterregulatory axis appears to exert antiobesity effects through the activation of two receptors, the G protein-coupled receptor (MasR) and Mas-related receptor type D (MrgD). The local RAS in adipose organ has prompted extensive research into white adipose tissue and brown adipose tissue (BAT), with a key role in regulating the cellular and metabolic plasticity of these tissues. The MasR activation favors the brown plasticity signature in the adipose organ by improve the thermogenesis, adipogenesis, and lipolysis, decrease the inflammatory state, and overall energy homeostasis. The MrgD metabolic effects are related to the maintenance of BAT functionality, but the signaling remains unexplored. This review provides a summary of RAS counterregulatory actions triggered by Mas and MrgD receptors on adipose tissue plasticity. Focus on the effects related to the morphology and function of adipose tissue, especially from animal studies, will be given targeting new avenues for treatment of obesity-associated metabolic effects.

Bisphenol S exposure induces cardiac remodeling and aggravates high-fat diet-induced cardiac hypertrophy in mice.

Bisphenol S (BPS) is widely used in the manufacture products and increase the risk of cardiovascular diseases. The effect of the association between obesity and BPS on cardiac outcomes is still unknown. Male C57BL/6 mice were divided into standard chow diet (SC; 15 kJ/g), standard chow diet + BPS (SCB), high-fat diet (HF; 21 kJ/g), and high-fat diet + BPS (HFB). Over 12 weeks, the groups were exposed to BPS through drinking water (dose: 25 µg/kg/day) and/or a HF diet. We evaluated: body mass (BM), total cholesterol, systolic blood pressure (SBP), left ventricle (LV) mass, and cardiac remodeling. In the SCB group, BM, total cholesterol, and SBP increase were augmented in relation to the SC group. In the HF and HFB groups, these parameters were higher than in the SC and SCB groups. Cardiac hypertrophy was evidenced by augmented LV mass and wall thickness, and ANP protein expression in all groups in comparison to the SC group. Only the HFB group had a thicker LV wall than SCB and HF groups, and increased cardiomyocyte area when compared with SC and SCB groups. Concerning cardiac fibrosis, SCB, HF, and HFB groups presented higher interstitial collagen area, TGFß, and α-SMA protein expression than the SC group. Perivascular collagen area was increased only in the HF and HFB groups than SC group. Higher IL-6, TNFα, and CD11c protein expression in all groups than the SC group evidenced inflammation. All groups had elevated CD36 and PPARα protein expression in relation to the SC group, but only HF and HFB groups promoted cardiac steatosis with increased perilipin 5 protein expression than the SC group. BPS exposure alone promoted cardiac remodeling with pathological concentric hypertrophy, fibrosis, and inflammation. Diet-induced remodeling is aggravated when associated with BPS, with marked hypertrophy, alongside fibrosis, inflammation, and lipid accumulation.

Renin-angiotensin system modulation through enalapril and/or exercise training improves visceral adiposity in obese mice.

INTRODUCTION: Obesity-related metabolic diseases occur as a result of disruptions in white adipose tissue (WAT) plasticity, especially through visceral fat accumulation and adipocyte hypertrophy. This study aimed to evaluate the impact of renin-angiotensin system (RAS) and bradykinin receptors modulation by enalapril treatment and/or exercise training on WAT morphology and related deleterious outcomes. METHODS: Male C57BL/6 mice were fed either a standard chow or a high-fat (HF) diet for 16 weeks. At the 8th week, HF-fed animals were divided into sedentary (HF), enalapril treatment (HF-E), exercise training (HF-T), and enalapril treatment plus exercise training (HF-ET) groups. Following the experimental protocol, body mass gain, adiposity index, insulin resistance, visceral WAT morphometry, renin-angiotensin system, and bradykinin receptors were evaluated. RESULTS: The HF group displayed increased adiposity, larger visceral fat mass, and adipocyte hypertrophy, which was accompanied by insulin resistance, overactivation of Ang II/AT1R arm, and favoring of B1R in bradykinin receptors profile. All interventions ameliorated visceral adiposity and related outcomes by favoring the Ang 1-7/MasR arm and the B2R expression in B1R/B2R ratio. However, combined therapy additively reduced Ang II/Ang 1-7 ratio. CONCLUSION: Our results suggest that Ang 1-7/MasR arm and B2R activation might be relevant targets in the treatment of visceral obesity.