Exercise training impacts skeletal muscle remodelling induced by metabolic syndrome in ZSF1 rats through metabolism regulation

Metabolism and bioenergetics in the pathophysiology of organ fibrosis

Fibrosis is the tissue scarring characterized by excess deposition of extracellular matrix (ECM) proteins, mainly collagens. A fibrotic response can take place in any tissue of the body and is the result of an imbalanced reaction to inflammation and wound healing. Metabolism has emerged as a major driver of fibrotic diseases. While glycolytic shifts appear to be a key metabolic switch in activated stromal ECM-producing cells, several other cell types such as immune cells, whose functions are intricately connected to their metabolic characteristics, form a complex network of pro-fibrotic cellular crosstalk. This review purports to clarify shared and particular cellular responses and mechanisms across organs and etiologies. We discuss the impact of the cell-type specific metabolic reprogramming in fibrotic diseases in both experimental and human pathology settings, providing a rationale for new therapeutic interventions based on metabolism-targeted antifibrotic agents.

The effect of long-term moderate exercise on myocardial metabolome in rats

Regular moderate physical exercise is beneficial for the cardiovascular system. Our prior study has demonstrated a long-term moderate exercise (4-week of 60-min 74.0% V̇O2max treadmill running) is optimal in protecting from exhaustive exercise-induced cardiac ischemic injury. This study is aimed to investigate the effect of long-term moderate exercise on myocardial metabolome in rats. Thirteen male Sprague-Dawley rats were randomly assigned into the control group (C) and the long-term moderate exercise group (E). The targeted metabolomics of the myocardium was analyzed by ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) system. Results showed that the metabolites categories of bile acids (BAs), fatty acids (FAs), and phenylpropanoic acids were significantly decreased. The biosynthesis of unsaturated FAs pathway was significantly downregulated. The altered metabolites in the E Group included decreased FAs (pentadecanoic acid, 10Z-heptadecenoic acid, dihomo-gamma-linolenic acid, docosahexaenoic acid, docosapentaenoic acid, and 10Z-nonadecenoic acid), decreased BAs (chenodeoxycholic acid and beta-muricholic acid), decreased organic acids (glycolic acid and 2-hydroxyglutaric acid), decreased carbohydrate (N-acetylneuraminic acid, Neu5Ac), decreased amino acids (α-aminobutyric acid and norvaline), decreased phenylpropanoic acids (hydroxyphenyllactic acid), and benzoic acids (4-hydroxybenzoic acid and phthalic acid). The results indicated that long-term moderate exercise has promoted lipids utilization in myocardium while exerted little influence on carbohydrate metabolism and diminished many detrimental metabolites. Notably, decrease of myocardial carbohydrate Neu5Ac after long-term moderate exercise might predict a prospective metabolomics biomarker for cardioprotection. This research has displayed the effect of long-term moderate exercise on myocardial metabolomic profiling in rats and indicated some promising metabolites which can be applied for exercise benefits in future.

Aerobic Exercise Ameliorates Muscle Atrophy Induced by Methylglyoxal via Increasing Gastrocnemius and Extensor Digitorum Longus Muscle Sensitivity

Muscle atrophy is characterized by the loss of muscle function. Many efforts are being made to prevent muscle atrophy, and exercise is an important alternative. Methylglyoxal is a well-known causative agent of metabolic diseases and diabetic complications. This study aimed to evaluate whether methylglyoxal induces muscle atrophy and to evaluate the ameliorative effect of moderate-intensity aerobic exercise in a methylglyoxal-induced muscle atrophy animal model. Each mouse was randomly divided into three groups: control, methylglyoxal-treated, and methylglyoxal-treated within aerobic exercise. In the exercise group, each mouse was trained on a treadmill for 2 weeks. On the last day, all groups were evaluated for several atrophic behaviors and skeletal muscles, including the soleus, plantaris, gastrocnemius, and extensor digitorum longus were analyzed. In the exercise group, muscle mass was restored, causing in attenuation of muscle atrophy. The gastrocnemius and extensor digitorum longus muscles showed improved fiber cross-sectional area and reduced myofibrils. Further, they produced regulated atrophy-related proteins (i.e., muscle atrophy F-box, muscle RING-finger protein-1, and myosin heavy chain), indicating that aerobic exercise stimulated their muscle sensitivity to reverse skeletal muscle atrophy. In conclusion, shortness of the gastrocnemius caused by methylglyoxal may induce the dynamic imbalance of skeletal muscle atrophy, thus methylglyoxal may be a key target for treating skeletal muscle atrophy. To this end, aerobic exercise may be a powerful tool for regulating methylglyoxal-induced skeletal muscle atrophy.