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Obesity over‐activates the classical arm of the renin‐angiotensin system (RAS), impairing skeletal muscle remodeling. We aimed to compare the effect of exercise training and enalapril, an angiotensin‐converting enzyme inhibitor, on RAS modulation in the skeletal muscle of obese animals. Thus, we divided C57BL/6 mice into two groups: standard chow (SC) and high‐fat (HF) diet for 16 weeks. At the eighth week, the HF‐fed animals were divided into four subgroups—sedentary (HF), treated with enalapril (HF‐E), exercise training protocol (HF‐T), and combined interventions (HF‐ET). After 8 weeks of treatment, we evaluated body mass and index (BMI), body composition, exercise capacity, muscle morphology, and skeletal muscle molecular markers. All interventions resulted in lower BMI and attenuation of overactivation in the classical arm, while favoring the B2R in the bradykinin receptors profile. This was associated with reduced apoptosis markers in obese skeletal muscles. The HF‐T group showed an increase in muscle mass and expression of biosynthesis markers and a reduction in expression of degradation markers and muscle fiber atrophy due to obesity. These findings suggest that the combination intervention did not have a synergistic effect against obesity‐induced muscle remodeling. Additionally, the use of enalapril impaired muscle's physiological adaptations to exercise training. [ABSTRACT FROM AUTHOR]

Endoplasmic reticulum (ER) stress poses a new pathological mechanism for metabolic-associated fatty liver disease (MAFLD). MAFLD treatment has encompassed renin-angiotensin system (RAS) blockers and aerobic exercise training, but their association with hepatic ER stress is not well known. Therefore, we aimed to compare the effects of hepatic RAS modulation by enalapril and/or aerobic exercise training over ER stress in MAFLD caused by a diet-induced obesity model. C57BL/6 mice were fed a standard-chow (CON, n = 10) or a high-fat (HF, n = 40) diet for 8 weeks. HF group was then randomly divided into: HF (n = 10), HF + Enalapril (EN, n = 10), HF + Aerobic exercise training (AET, n = 10), and HF + Enalapril+Aerobic exercise training (EN + AET, n = 10) for 8 more weeks. Body mass (BM) and glucose profile were evaluated. In the liver, ACE and ACE2 activity, morphology, lipid profile, and protein expression of ER stress and metabolic markers were assessed. Both enalapril and aerobic exercise training provided comparable efficacy in improving diet-induced MAFLD through modulation of RAS and ER stress, but the latter was more efficient in improving ER stress, liver damage and metabolism. This is the first study to evaluate pharmacological (enalapril) and non-pharmacological (aerobic exercise training) RAS modulators associated with ER stress in a diet-induced MAFLD model. HF diet led to favoring of the RAS classical arm and increased ER stress through higher expression of the eIF2α pathway. These results could be related to HF diet-associated insulin resistance and upregulation of gluconeogenesis enzymes PEPCK and G6Pase, as well as lipid accumulation through increased lipogenic transcription factor SREBP1c and lower PPARα levels. Enalapril treatment, aerobic exercise training, and the combination of both interventions were able to favor the RAS counterregulatory arm, improve ER stress and decrease lipid accumulation. All interventions were also able to improve insulin resistance, although aerobic exercise training showed more efficiency, reverting glucose intolerance and decreasing the expression of PEPCK. Aerobic exercise training was also the only intervention able to reduce binucleation of hepatocytes and the association with enalapril treatment reverted the increase in hepatocytes with two or more nuclei, which could be suggestive of liver damage associated with the pharmacological treatment. [Display omitted] • Enalapril and aerobic exercise training decrease ACE/ACE2 ratio in obese mice. • RAS counterregulatory arm could be associated to decreased ER stress markers in MAFLD. • Aerobic exercise training better improved liver ER stress markers, metabolism and damage. [ABSTRACT FROM AUTHOR]

Endoplasmic reticulum (ER) stress poses a new pathological mechanism for metabolic-associated fatty liver disease (MAFLD). MAFLD treatment has encompassed renin-angiotensin system (RAS) blockers and aerobic exercise training, but their association with hepatic ER stress is not well known. Therefore, we aimed to compare the effects of hepatic RAS modulation by enalapril and/or aerobic exercise training over ER stress in MAFLD caused by a diet-induced obesity model. C57BL/6 mice were fed a standard-chow (CON, n = 10) or a high-fat (HF, n = 40) diet for 8 weeks. HF group was then randomly divided into: HF (n = 10), HF + Enalapril (EN, n = 10), HF + Aerobic exercise training (AET, n = 10), and HF + Enalapril+Aerobic exercise training (EN + AET, n = 10) for 8 more weeks. Body mass (BM) and glucose profile were evaluated. In the liver, ACE and ACE2 activity, morphology, lipid profile, and protein expression of ER stress and metabolic markers were assessed. Both enalapril and aerobic exercise training provided comparable efficacy in improving diet-induced MAFLD through modulation of RAS and ER stress, but the latter was more efficient in improving ER stress, liver damage and metabolism. This is the first study to evaluate pharmacological (enalapril) and non-pharmacological (aerobic exercise training) RAS modulators associated with ER stress in a diet-induced MAFLD model. HF diet led to favoring of the RAS classical arm and increased ER stress through higher expression of the eIF2α pathway. These results could be related to HF diet-associated insulin resistance and upregulation of gluconeogenesis enzymes PEPCK and G6Pase, as well as lipid accumulation through increased lipogenic transcription factor SREBP1c and lower PPARα levels. Enalapril treatment, aerobic exercise training, and the combination of both interventions were able to favor the RAS counterregulatory arm, improve ER stress and decrease lipid accumulation. All interventions were also able to improve insulin resistance, although aerobic exercise training showed more efficiency, reverting glucose intolerance and decreasing the expression of PEPCK. Aerobic exercise training was also the only intervention able to reduce binucleation of hepatocytes and the association with enalapril treatment reverted the increase in hepatocytes with two or more nuclei, which could be suggestive of liver damage associated with the pharmacological treatment. [Display omitted] • Enalapril and aerobic exercise training decrease ACE/ACE2 ratio in obese mice. • RAS counterregulatory arm could be associated to decreased ER stress markers in MAFLD. • Aerobic exercise training better improved liver ER stress markers, metabolism and damage. [ABSTRACT FROM AUTHOR]

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. 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. 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. Our results suggest that Ang 1–7/MasR arm and B2R activation might be relevant targets in the treatment of visceral obesity. • Enalapril treatment and exercise training ameliorates visceral adiposity. • Visceral adiposity is related to Ang II/AT1R and B1R overexpression in vWAT. • The interventions favor the counterregulatory arm of visceral adipose RAS. • Combined therapy additively reduces Ang II/Ang 1–7 ratio in vWAT. • The interventions shift the bradykinin receptor profile towards B2R in vWAT. [ABSTRACT FROM AUTHOR]

The renin-angiotensin (Ang) system (RAS) is a complex hormonal system present locally in several tissues such as cardiovascular organs. RAS deregulation through overactivation of the classical arm [Ang-converting enzyme (ACE)/Ang-II/Ang type 1 receptor (AT1R)] has been linked to the development of cardiovascular diseases and activation of endoplasmic reticulum (ER) stress pathways. The ER stress is a condition that, if unresolved, might lead to heart failure, atherosclerosis, hypertension, and endothelial dysfunction. Accumulated evidence has shown that the RAS modulates the UPR activation. Several studies reported increased ER stress markers in response to Ang-II treatment, in both in vivo and in vitro models. Evidence has also pointed that targeting the RAS classical arm through RAS blockers, gene silencing or genetic models leads to lower levels of ER stress markers. Few studies demonstrated protective effects of the counter-regulatory arm (ACE-2/Ang-(1-7)/Mas receptor) over ER stress. However, the crosstalk mechanisms between the arms of the RAS and ER stress remain unclear. In this review, we sought to explore the classical arm of the RAS as a key mechanism in UPR activation and to suggest a possible protective role of the counter-regulatory arm in mitigating ER stress. [Display omitted] • Ang-II leads to endoplasmic reticulum (ER) stress through diverse mechanisms. • Blocking the renin-angiotensin system (RAS) classic arm leads to lower ER stress. • The RAS counter-regulatory arm may exert protection against ER stress. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]