Effects of losartan and exercise on muscle mass and exercise endurance of old mice

Obesity-induced skeletal muscle remodeling: A comparative analysis of exercise training and ACE-inhibitory drug in male mice

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.

Is sarcopenia an associated factor of increased administration of specific medications in patients with heart failure? A systematic review and meta-analysis

Background

There is controversy in relation to commonly used drugs in heart failure (HF) and their impact on muscle function. The aim of this study was to evaluate the odds of receiving specific medications often used in clinical practice by patients with HF and sarcopenia vs. without sarcopenia.

Methods

A systematic literature search of cohort studies via databases (PubMed, Web of Science, Scopus, and Cochrane Library) was conducted from inception until March 2023. To determine if sarcopenia is linked to a higher number of specific HF-related medications, a meta-analysis using a random-effects model was used to calculate the pooled effects.

Results

Our main analyses showed no significant association of sarcopenia with administration of higher HF-related medication count vs. those without sarcopenia. Those with lower appendicular lean mass (ALM) had significantly lower odds of receiving angiotensin converting enzyme inhibitors (ACE-Is)/angiotensin receptor blockers (ARBs) (OR: 0.68, 95%CI 0.50-0.90, I2 = 12%, P < 0.01) vs. patients with higher ALM for which age could be an important confounder based on meta-regression. No statistically significant differences were found in relation to B-blockers OR: 0.84, 95%CI 0.63-1.12, I2 = 7%, P = 0.24) and loop diuretics (OR: 1.19, 95%CI 0.87-1.63, I2 = 0%, P = 0.27). Regarding handgrip strength, gait speed, and short physical performance battery, our narrative synthesis found mixed results.

Conclusion

This systematic review and meta-analysis did not find a relationship of specific medication count in sarcopenia vs. without sarcopenia in patients with HF, although increased odds of ACE-I/ARB was shown in those with higher ALM.

Systematic Review Registration

PROSPERO (CRD42023411137).

Losartan alleviates renal fibrosis by inhibiting the biomechanical stress-induced epithelial-mesenchymal transition of renal epithelial cells

Angiotensin receptor blockers (ARBs) have been reported to be beneficial of renal fibrosis, but the molecular and cellular mechanisms are still unclear. In this study, we investigated the effectiveness and relevant mechanism of ARBs in alleviating renal fibrosis, especially by focusing on biomechanical stress-induced epithelial to mesenchymal transition (EMT) of renal epithelial cells. Unilateral ureteral obstruction (UUO) renal fibrosis model was established in mice by ligating the left ureter, and then randomly received losartan at a low dose (1 mg/kg) or a regular dose (3 mg/kg) for 2 weeks. Compared to the control, histological analysis showed that losartan treatment at either a low dose or a regular dose effectively attenuated renal fibrosis in the UUO model. To further understand the mechanism, we ex vivo loaded primary human renal epithelial cells to 50 mmHg hydrostatic pressure. Western blot and immunostaining analyses indicated that the loading to 50 mmHg hydrostatic pressure for 24 h significantly upregulated vimentin, β-catenin and α-SMA, but downregulated E-cadherin in renal epithelial cells, suggesting the EMT. The addition of 10 or 100 nM losartan in medium effectively attenuated the EMT of renal epithelial cells induced by 50 mmHg hydrostatic pressure loading. Our in vivo and ex vivo experimental data suggest that losartan treatment, even at a low dose can effectively alleviate renal fibrosis in mouse UUO model, at least partly by inhibiting the biomechanical stress-induced EMT of renal epithelial cells. A low dose of ARBs may repurpose for renal fibrosis treatment.

Insights into Pathogenesis, Nutritional and Drug Approach in Sarcopenia: A Systematic Review

Sarcopenia is a multifactorial condition related to the loss of muscle mass and strength due to aging, eating habits, physical inactivity, or even caused by another disease. Affected individuals have a higher risk of falls and may be associated with heart disease, respiratory diseases, cognitive impairment, and consequently an increased risk of hospitalization, in addition to causing an economic impact due to the high cost of care during the stay in hospitals. The standardization of appropriate treatment for patients with sarcopenia that could help reduce pathology-related morbidity is necessary. For these reasons, this study aimed to perform a systematic review of the role of nutrition and drugs that could ameliorate the health and quality of life of sarcopenic patients and PRISMA guidelines were followed. Lifestyle interventions have shown a profound impact on sarcopenia treatment but using supplements and different drugs can also impact skeletal muscle maintenance. Creatine, leucine, branched-chain amino acids, omega 3, and vitamin D can show benefits. Although with controversial results, medications such as Metformin, GLP-1, losartan, statin, growth hormone, and dipeptidyl peptidase 4 inhibitors have also been considered and can alter the sarcopenic's metabolic parameters, protect against cardiovascular diseases and outcomes, while protecting muscles.

Effect of losartan treatment on Smad signaling and recovery from hindlimb unloading-induced soleus muscle atrophy in female rats

Losartan, an angiotensin II type 1 receptor blocker, exerts protective effect on soleus muscle atrophy in female rats. Thus, we aimed to examine the effect of losartan treatment on the recovery of atrophied soleus muscles. Female Wistar rats were subjected to hindlimb unloading for 7 d and then reloading for 7 d with either phosphate-buffered saline (PBS; n = 9) or losartan (40 mg/kg/day; n = 9). The soleus muscles were removed at rest (sedentary control [SED]; n = 9), after 7 d of hindlimb unloading (HU; n = 9), and after 7 d of reloading (HUR-PBS or HUR-LOS; n = 9 each). The absolute and relative weights, and fiber cross-sectional area (CSA) of the soleus muscles of rats in the HU group were significantly reduced as compared to those of the rats in the SED group at 7 d post-hindlimb unloading. Seven days of reloading significantly increased the muscle weights of rats in the HUR-PBS and HUR-LOS groups, with the recovery rate of the absolute muscle weight and type I fiber CSA being significantly higher in the HUR-LOS group (6.1% and 10.1%, respectively) than in the HUR-PBS group (4.7% and 5.2%, respectively) (p < 0.05). Moreover, the absolute and relative muscle weight in HUR-PBS were lower than SED; however, no significant difference was observed between the SED and HUR-LOS groups. CSAs of type I and IIa fiber were significantly higher in the HUR-LOS group than in the HU group. Losartan administration during reloading resulted in increased Smad1/5/8 and mTOR signaling and decreased Smad2/3 signaling and protein ubiquitination, facilitating the recovery of atrophied soleus muscle. Therefore, losartan administration-induced muscle recovery may partially be attributed to enhanced Smad1/5/8 and mTOR signaling activation, and reduced activation of canonical TGF-β signaling (Smad2/3) in the soleus muscle.