Nutritional Strategies for Muscle Atrophy: Current Evidence and Underlying Mechanisms

Skeletal muscle can undergo detrimental changes in various diseases, leading to muscle dysfunction and atrophy, thus severely affecting people's lives. Along with exercise, there is a growing interest in the potential of nutritional support against muscle atrophy. This review provides a brief overview of the molecular mechanisms driving skeletal muscle atrophy and summarizes recent advances in nutritional interventions for preventing and treating muscle atrophy. The nutritional supplements include amino acids and their derivatives (such as leucine, β-hydroxy, β-methylbutyrate, and creatine), various antioxidant supplements (like Coenzyme Q10 and mitoquinone, resveratrol, curcumin, quercetin, Omega 3 fatty acids), minerals (such as magnesium and selenium), and vitamins (such as vitamin B, vitamin C, vitamin D, and vitamin E), as well as probiotics and prebiotics (like Lactobacillus, Bifidobacterium, and 1-kestose). Furthermore, the study discusses the impact of a combined approach involving nutritional support and physical therapy to prevent muscle atrophy, suggests appropriate multi-nutritional and multi-modal interventions based on individual conditions to optimize treatment outcomes, and enhances the recovery of muscle function for patients. By understanding the molecular mechanisms behind skeletal muscle atrophy and implementing appropriate interventions, it is possible to enhance the recovery of muscle function and improve patients' quality of life.

Single-Cell RNA Sequencing Analysis of Microglia Dissected the Energy Metabolism and Revealed Potential Biomarkers in Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a common neurodegenerative disease, accompanied by the gradual loss of motor neuron, even life-threatening. However, the pathogenesis, early diagnosis, and effective strategies of ALS are not yet completely understood. In this study, the function of differentially expressed genes (DEGs) in non-neuronal cells of the primary motor cortex of ALS patients (DATA1), the brainstem of SOD1 mutant ALS mice (DATA2), and the whole blood tissue of ALS patients (DATA3) were explored. The results showed that the functions of DEGs in non-neuronal cells were mainly related to energy metabolism (such as oxidative phosphorylation) and protein synthesis. In non-neuronal cells, six upregulated DEGs (HSPA8, SOD1, CALM1, CALM2, NEFL, COX6C) and three downregulated DEGs (SNRNP70, HSPA1A, HSPA1B) might be key factors in regulating ALS. Microglia played a key role in the development of ALS. The expression of SOD1 and TUBA4A in microglia in DATA1 was significantly increased. The integration analysis of DEGs in DATA1 and DATA2 showed that SOD1 and CALM1 might be potential biomarkers. The integration analysis of DEGs in DATA1 and DATA3 showed that CALM2 and HSPA1A might be potential biomarkers. Cell interaction showed that the interaction between microglia and other cells was reduced in high oxidative phosphorylation states, which might be a risk factor in ALS. Our research provided evidence for the pathogenesis, early diagnosis, and potential targeted therapy for ALS.

Duchenne muscular dystrophy: pathogenesis and promising therapies

Duchenne muscular dystrophy (DMD) is a severe, progressive, muscle-wasting disease, characterized by progressive deterioration of skeletal muscle that causes rapid loss of mobility. The failure in respiratory and cardiac muscles is the underlying cause of premature death in most patients with DMD. Mutations in the gene encoding dystrophin result in dystrophin deficiency, which is the underlying pathogenesis of DMD. Dystrophin-deficient myocytes are dysfunctional and vulnerable to injury, triggering a series of subsequent pathological changes. In this review, we detail the molecular mechanism of DMD, dystrophin deficiency-induced muscle cell damage (oxidative stress injury, dysregulated calcium homeostasis, and sarcolemma instability) and other cell damage and dysfunction (neuromuscular junction impairment and abnormal differentiation of muscle satellite). We also describe aberrant function of other cells and impaired muscle regeneration due to deterioration of the muscle microenvironment, and dystrophin deficiency-induced multiple organ dysfunction, while summarizing the recent advances in the treatment of DMD.