Oxidative stress: roles in skeletal muscle atrophy

Oxidative balance score is inversely associated with low muscle mass in young and middle-aged adults: a cross-sectional NHANES study

BACKGROUND

Low muscle mass is a critical indicator of frailty and adverse health outcomes. However, the potential link between systemic oxidative stress and low muscle mass remains underexplored. This study aims to investigate the association between the Oxidative Balance Score (OBS) and low muscle mass in U.S. adults.

METHODS

In this cross-sectional study, data from 4096 adults aged 20 to 59 years from National Health and Nutritional Examination Survey (NHANES) 2011 to 2018 were analyzed. Low muscle mass, the primary outcome, was evaluated utilizing the Foundation for the National Institutes of Health (FNIH) definition. Analysis involved the application of restricted cubic splines and weighted multivariate regression techniques.

RESULTS

A nonlinear association was observed between OBS and low muscle mass (p for nonlinearity < 0.0049). Compared to the lowest OBS quartile, individuals in the highest quartile had an adjusted OR of 0.26 (95% CI: 0.14-0.48) for low muscle mass (P for trend < 0.001). Additionally, the adjusted β value for ALM/BMI was 0.067 (95% CI: 0.053-0.082), P for trend < 0.001. Both dietary and lifestyle OBS also showed negative associations with low muscle mass, with fully adjusted ORs of 0.38 (95% CI: 0.19-0.76) and 0.17 (95% CI: 0.05-0.62), respectively (both P for trends < 0.01). Furthermore, in stratified analyses, this relationship was particularly prominent in the 40-59 years age group (P for interaction = 0.048).

CONCLUSION

Higher OBS, indicative of greater antioxidant exposure, was robustly associated with a lower risk of low muscle mass, particularly in 40-59 old adults. These findings underscore the potential role of oxidative balance in preserving muscle health and highlight the need for targeted interventions in this demographic. Further longitudinal studies are warranted to confirm these associations and evaluate potential clinical applications.

Oxidative balance score is independently associated with reduced prevalence of sarcopenia among US adults with metabolic syndrome

Background

This research seeks to explore the link between the oxidative balance score (OBS) and sarcopenia in American adults with Metabolic Syndrome (MetS) using data from a national, population-based survey.

Methods

The study included 3,625 participants diagnosed with Metabolic Syndrome, all aged 20 years and above, derived from NHANES datasets spanning 1999-2006 and 2011-2018. OBS evaluation was based on 16 dietary and 4 lifestyle elements. MetS diagnosis followed the NCEP-ATP III guidelines, while sarcopenia identification was based on FNIH standards. We employed multivariate logistic regression analyses to delve into the connections between OBS and sarcopenia within the MetS cohort.

Results

Sarcopenia was found in 17.46% of the participants. In models adjusted for all variables, OBS, dietary OBS, and lifestyle OBS each showed a significant inverse relationship with sarcopenia among MetS individuals [OBS: OR = 0.959, 95%CI: (0.948, 0.982), P trend = 0.0005; dietary OBS: OR = 0.963, 95%CI: (0.939, 0.989), P trend = 0.0055; lifestyle OBS: OR = 0.860, 95%CI: (0.787, 0.939), P trend = 0.0011]. Higher scores in OBS were consistently linked with a decreased incidence of sarcopenia (all P for trend < 0.05). Restricted cubic spline analysis confirmed that these relationships were linear. The impact of age was significant, with OBS benefits only observed in those aged 40 and older.

Conclusions

Maintaining a diet and lifestyle rich in antioxidants is both independently and collectively linked with a lower occurrence of sarcopenia in individuals with MetS. These results bolster the proposition of developing OBS-centered preventive strategies for sarcopenia in MetS patients, particularly those aged 40 years and older.

Cadmium treatment induces oxidative damage and apoptosis in vitro skeletal muscle cells

Cadmium is a prevalent environmental contaminant, and current research indicates that exposure to cadmium is a significant risk factor contributing to the increased incidence of sarcopenia. However, the precise mechanisms by which cadmium exposure leads to skeletal muscle damage remain to be fully elucidated. Utilizing an in vitro culture model of mouse C2C12 myoblasts, this study exposed cells to 0, 2, 4, and 8 μmol/L cadmium chloride for 24 hours to evaluate the cellular damage and explore the potential mechanisms. Our present data of this study demonstrate that cadmium treatment results in a reduction of C2C12 cell viability, an increased release of lactate dehydrogenase, and an imbalance in the oxidative-antioxidant system characterized by an excessive accumulation of reactive oxygen species, elevated malondialdehyde production, and decreased superoxide dismutase activity. Additionally, there is an upregulation of nuclear factor-erythroid 2-related factor 2, heme oxygenase-1, NAD(P)H quinone oxidoreductase 1, and glutamate-cysteine ligase catalytic subunit protein expression, along with a downregulation of superoxide dismutase 1 protein expression. Furthermore, cadmium exposure mediates an increase in cysteinyl aspartate specific proteinase-dependent apoptosis via the mitochondrial pathway, as indicated by an increased apoptosis rate, elevated Bcl-2 associated X protein and cysteinyl aspartate specific proteinase 3 protein expression, and a decreased expression of B-cell lymphoma-2 protein. Our findings elucidate the mechanisms of cadmium-induced cytotoxic damage in skeletal muscle cells from the perspectives of oxidative injury and apoptosis, thereby providing a theoretical basis for the prevention and treatment of cadmium toxicity.

Marine-Derived Bioactive Compounds: A Promising Strategy for Ameliorating Skeletal Muscle Dysfunction in COPD

Chronic obstructive pulmonary disease (COPD) is frequently accompanied by skeletal muscle dysfunction, a critical and severe extrapulmonary complication. This dysfunction contributes to reduced exercise capacity, increased frequency of acute exacerbations, and elevated mortality, serving as an independent risk factor for poor prognosis in COPD patients. Owing to the unique physicochemical conditions of the marine environment, marine-derived bioactive compounds exhibit potent anti-inflammatory and antioxidant properties, demonstrating therapeutic potential for ameliorating COPD skeletal muscle dysfunction. This review summarizes marine-derived bioactive compounds with promising efficacy against skeletal muscle dysfunction in COPD, including polysaccharides, lipids, polyphenols, peptides, and carotenoids. The discussed compounds have shown bioactivities in promoting skeletal muscle health and suppressing muscle atrophy, thereby providing potential strategies for the prevention and treatment of COPD skeletal muscle dysfunction. These findings may expand the therapeutic strategies for managing COPD skeletal muscle dysfunction.

Astragaloside IV Improves Muscle Atrophy by Modulating the Activity of UPS and ALP via Suppressing Oxidative Stress and Inflammation in Denervated Mice

Peripheral nerve injury is common clinically and can lead to neuronal degeneration and atrophy and fibrosis of the target muscle. The molecular mechanisms of muscle atrophy induced by denervation are complex and not fully understood. Inflammation and oxidative stress play an important triggering role in denervated muscle atrophy. Astragaloside IV (ASIV), a monomeric compound purified from astragalus membranaceus, has antioxidant and anti-inflammatory properties. The aim of this study was to investigate the effect of ASIV on denervated muscle atrophy and its molecular mechanism, so as to provide a new potential therapeutic target for the prevention and treatment of denervated muscle atrophy. In this study, an ICR mouse model of muscle atrophy was generated through sciatic nerve dissection. We found that ASIV significantly inhibited the reduction of tibialis anterior muscle mass and muscle fiber cross-sectional area in denervated mice, reducing ROS and oxidative stress-related protein levels. Furthermore, ASIV inhibits the increase in inflammation-associated proteins and infiltration of inflammatory cells, protecting the denervated microvessels in skeletal muscle. We also found that ASIV reduced the expression levels of MAFbx, MuRF1 and FoxO3a, while decreasing the expression levels of autophagy-related proteins, it inhibited the activation of ubiquitin-proteasome and autophagy-lysosome hydrolysis systems and the slow-to-fast myofiber shift. Our results show that ASIV inhibits oxidative stress and inflammatory responses in skeletal muscle due to denervation, inhibits mitophagy and proteolysis, improves microvascular circulation and reverses the transition of muscle fiber types; Therefore, the process of skeletal muscle atrophy caused by denervation can be effectively delayed.

Targeting RAGE-signaling pathways in the repair of rotator-cuff injury

Rotator cuff injury (RCI) is a common musculoskeletal problem that can have a significant impact on the quality of life and functional abilities of those affected. Novel therapies, including proteomics-based, stem cells, platelet-rich plasma, and exosomes, are being developed to promote rotator-cuff healing. The receptor for advanced glycation end-products (RAGE) is a multifunctional receptor that is expressed on several cell types and is implicated in several physiologic and pathological processes, such as tissue repair, inflammation, and degeneration. Because of its capacity to bind with a variety of ligands and initiate signaling pathways that lead to inflammatory responses in RCI, RAGE plays a crucial role in inflammation. In this critical review article, we discussed the role of RAGE-mediated persistent inflammation in RCI followed by novel factors including PKCs, TIRAP, DIAPH1, and factors related to muscle injury with their therapeutic potential in RCI. These factors involve various aspects of muscle injury and signaling and the possibility of targeting these factors to improve the clinical outcomes in RCI still needs further investigation.

Endoplasmic reticulum stress and unfolded protein response: Roles in skeletal muscle atrophy

Skeletal muscle atrophy is commonly present in various pathological states, posing a huge burden on society and patients. Increased protein hydrolysis, decreased protein synthesis, inflammatory response, oxidative stress, mitochondrial dysfunction, endoplasmic reticulum stress (ERS) and unfolded protein response (UPR) are all important molecular mechanisms involved in the occurrence and development of skeletal muscle atrophy. The potential mechanisms of ERS and UPR in skeletal muscle atrophy are extremely complex and have not yet been fully elucidated. This article elucidates the molecular mechanisms of ERS and UPR, and discusses their effects on different types of muscle atrophy (muscle atrophy caused by disuse, cachexia, chronic kidney disease (CKD), diabetes mellitus (DM), amyotrophic lateral sclerosis (ALS), spinal muscular atrophy (SMA), spinal and bulbar muscular atrophy (SBMA), aging, sarcopenia, obesity, and starvation), and explores the preventive and therapeutic strategies targeting ERS and UPR in skeletal muscle atrophy, including inhibitor therapy and drug therapy. This review aims to emphasize the importance of endoplasmic reticulum (ER) in maintaining skeletal muscle homeostasis, which helps us further understand the molecular mechanisms of skeletal muscle atrophy and provides new ideas and insights for the development of effective therapeutic drugs and preventive measures for skeletal muscle atrophy.

In Vivo Reprogramming of Tissue-Derived Extracellular Vesicles for Treating Chronic Tissue Injury Through Metabolic Engineering

Extracellular vesicles (EVs) have emerged as promising therapeutics for regenerative medicine, but the efficacy of current exogenous EV-based therapies for treating chronic tissue injury is still unsatisfactory. Exercise can affect skeletal muscle EV secretion and that this process regulates the systemic health-promoting role of exercise, suggesting that fine-tuning of endogenous tissue EV secretion may provide a new therapeutic avenue. Here, this work reports that in vivo reprogramming of EV secretion via metabolic engineering is a promising strategy for treating chronic diseases. Briefly, exercise enhanced mitochondrial metabolism and EV production in healthy skeletal muscles, and EVs from healthy skeletal muscles subjected to exercise or metabolic engineering (boosting mitochondrial biogenesis via AAV-mediated muscle-specific TFAM overexpression) exerted cellular protective effects in vitro. In injured skeletal muscles, in vivo metabolic engineering therapy could reprogram EV secretion patterns (reducing pathological EV compositions while increasing beneficial EV compositions) by regulating multiple EV biogenesis and cargo sorting pathways. Reprogrammed muscle-derived EVs could reach major organs and tissues via the circulation and then simultaneously attenuated multiple-tissue (e.g., muscle and kidney) injury in chronic kidney disease. This study highlights that in vivo reprogramming of tissue-derived EVs via a metabolic engineering approach is a potential strategy for treating diverse chronic diseases.

Association between urinary volatile organic compound metabolites and sarcopenia in the US general population: a cross-sectional NHANES study from 2011 to 2018

Volatile organic compound (VOC) is a prevalent form of pollutant that has been linked to various human ailments, yet their connection to sarcopenia remains uncertain. This study seeks to examine the potential association between exposure to mixtures of metabolites of volatile organic compounds (mVOCs) and sarcopenia, while also investigating the potential mediating effects of oxidative stress and inflammation. Data from the 2011-2018 National Health and Nutrition Examination Survey (NHANES) were utilized for the analysis of the relationship between mVOCs and sarcopenia through logistic regression. The least absolute shrinkage and selection operator (LASSO) regression model was employed to identify key mVOCs, while the quantile-g computation model (qgcomp) and bayesian kernel machine regression (BKMR) models were utilized to examine the association between mVOC mixtures and sarcopenia. Potential mediating factors were explored through mediating analysis. Of the 2908 participants included in the study, 246 individuals (8.5%) were found to have sarcopenia. Logistic regression analysis revealed that five urinary VOC metabolites were positively correlated with an increased risk of sarcopenia. The key mVOCs identified through the LASSO method were further analyzed using qgcomp, which showed a 47% average increase in the risk of sarcopenia when exposed to a mixture of mVOCs (OR = 1.47, 95% CI 1.14-1.91). Four mVOCs components (DHBMA, 3HPMA, ATCA and 3,4MHA) have the largest weight. The BKMR results further confirm this joint association. Furthermore, Mediation analysis revealed that inflammation and oxidative stress mediate the relationship between exposure to mVOCs and sarcopenia. In conclusion, our study provides evidence suggesting that VOC exposure is linked to a heightened risk of sarcopenia, with inflammation and oxidative stress potentially serving as mediators in this relationship. It is recommended that additional cohort studies be conducted to validate these findings.

Modulating oxidative stress: a reliable strategy for coping with community-acquired pneumonia in older adults

Community-acquired pneumonia (CAP) remains one of the leading respiratory diseases worldwide. With the aging of the global population, the morbidity, criticality and mortality rates of CAP in older adults remain high every year. Modulating the signaling pathways that cause the inflammatory response and improve the immune function of patients has become the focus of reducing inflammatory damage in the lungs, especially CAP in older adults. As an important factor that causes the inflammatory response of CAP and affects the immune status of the body, oxidative stress plays an important role in the occurrence, development and treatment of CAP. Furthermore, in older adults with CAP, oxidative stress is closely associated with immune senescence, sarcopenia, frailty, aging, multimorbidity, and polypharmacy. Therefore, multiple perspectives combined with the disease characteristics of older adults with CAP were reviewed to clarify the research progress and application value of modulating oxidative stress in older adults with CAP. Clearly, there is no doubt that targeted modulation of oxidative stress benefits CAP in older adults. However, many challenges and unknowns concerning how to modulate oxidative stress for further practical clinical applications exist, and more targeted research is needed. Moreover, the limitations and challenges of modulating oxidative stress are analyzed with the aim of providing references and ideas for future clinical treatment or further research in older adults with CAP.

Effects of different photoperiods on melatonin level, cecal microbiota and breast muscle morphology of broiler chickens

Long photoperiods are often characterized by enhanced oxidative stress-induced damage to skeletal muscle, reduced melatonin (MT) levels and intestinal microbiota dysfunction in broilers. In this study, we aimed to investigate the association of breast muscle morphology with melatonin levels and the cecal microbiota of broilers under different photoperiods. A total of 216 healthy 5-day-old Arbor Acres (AA) male broilers were randomly assigned to 12 L:12D, 18 L:6D and 24 L:0D photoperiods for 4 weeks (L = hours of light, D = hours of darkness). The concentration of inflammatory factors and MT concentrations was measured using ELISA kits, whereas breast muscle morphology was examined through the hematoxylin (H) and eosin (E) staining, and microbiota composition was identified through 16 s rRNA analysis. Extended light exposure significantly improved the growth rate of broilers, but significantly decreased feed efficiency (FE). Furthermore, it upregulated the concentration of IL-1β, IL-6 and TNF-α and induced an abnormal breast muscle morphology. Extended light exposure significantly decreased MT levels in the hypothalamus, cecum and breast muscle, while triggering the cecal microbiota composition disorder. Specifically, there was significant alteration to the dominant bacterial phylum, following exposure to long photoperiods, with the abundance of Firmicutes decreasing and the abundance of Bacteroidota increasing. Notably, the relative abundance of Lactobacillus showed a positive correlation with MT levels and a negative correlation with inflammatory cytokines. In conclusion, the present findings indicated that extended light exposure reduced the MT levels, which were related to disturbed cecal microbiota, damaging breast muscle morphology and inducing breast muscle inflammation in broilers.

Nutritional Approach to Diabetic Sarcopenia: A Comprehensive Review

PURPOSE OF THE REVIEW

The aim of this review is to discuss and evaluate diabetic sarcopenia (DS) and its relationship with nutrition by discussing the mechanisms of diabetic sarcopenia in detail and comprehensively reviewing the literature.

RECENT FINDINGS

Type 2 diabetes (T2DM) affects approximately 25% of people aged 50 years and over and indicates a significant the cost of health for the elderly. Nutrition is an important part of these treatment approaches, and in this review, the literature was comprehensively reviewed, focusing on understanding the mechanisms of DS and discussing its relationship with nutrition. A comprehensive search was conducted on Web of Science, Google Scholar, Scopus, Science Direct, and PubMed from inception up to July 2024. The aim of nutritional treatment for DS is to improve muscle mass, muscle strength and physical performance while improving diabetes-related metabolic risk and glucose levels. In this context, it is important to determine energy intake in individuals with DS according to calorie intake exceeding 30 kcal/kg. For these individuals, a protein intake of at least 1-1.2 g/kg/day is recommended, with an emphasis on the number and timing of meals and a nutritional pattern rich in branched chain amino acids (BCAA). In addition, it is important to adopt a diet rich in antioxidants and to choose diet patterns that contain sufficient levels of macro and micronutrients. The Mediterranean diet model can be a good diet option for individuals with DS. Comprehensive studies in this field are needed so that clinicians can make specific dietary recommendations for DS.

Deuterium-reinforced polyunsaturated fatty acids protect against muscle atrophy by STZ-induced diabetic mice

Oxidative stress and reactive oxygen species (ROS) have been linked to muscle atrophy and weakness. Diabetes increases the oxidative status in all tissues, including muscle tissues, but the role of lipid ROS on diabetes-induced muscle atrophy is not fully understood. Deuterium reinforced polyunsaturated fatty acids (D-PUFA) are more resistant to ROS-initiated chain reaction of lipid peroxidation than regular hydrogenated PUFA (H-PUFA). In this study, we tested the hypothesis that D-PUFA would protect muscle atrophy induced by diabetes driven by an accumulation of lipid hydroperoxides (LOOH). C57BL/6J mice were dosed with H-PUFA or D-PUFA for four weeks through dietary supplementation (10 mg/day) and then injected with streptozotocin (STZ) to induce insulin-deficient diabetes. After two weeks, muscles tissues were analyzed for individual muscle mass, force generating capacity and cross-sectional area. Skeletal muscle fibers from diabetic mice exhibited increased total ROS and LOOH. This was abolished by the D-PUFA supplementation regardless of accumulated iron. D-PUFA were found to be protective against muscle atrophy and weakness from STZ-induced diabetes. Prevention of muscle atrophy and weakness by D-PUFA might be independent of ACSL4/LPCAT3/15-LOX pathway. These findings provide novel insights into the role of LOOH in the mechanistic link between oxidative stress and diabetic myopathy and suggest a novel therapeutic approach to diabetes-associated muscle weakness.

Network Pharmacology Combined with Experimental Validation to Investigate the Effects and Mechanisms of Aucubin on Aging-Related Muscle Atrophy

Aucubin (AU) is one of the main components of the traditional Chinese medicine Eucommia ulmoides Oliv (EU). This study investigated the effects of AU on aging-related skeletal muscle atrophy in vitro and in vivo. The results of network pharmacology revealed the potential therapeutic effects of AU on muscle atrophy. In vitro, AU effectively attenuated D-gal-induced cellular damage, reduced the number of senescence-associated β-galactosidase (SA-β-Gal)-positive cells, down-regulated the expression levels of muscle atrophy-related proteins Atrogin-1 and MuRF1, and improved myotube differentiation, thereby mitigating myotube atrophy. Notably, AU was found to attenuate oxidative stress and apoptosis in skeletal muscle cells by reducing ROS production, regulating Cleaved caspase3 and BAX/Bcl-2 expression in apoptotic pathways, and enhancing Sirt1 and PGC-1α signaling pathways. In vivo studies demonstrated that AU treatment extended the average lifespan of Caenorhabditis elegans (C. elegans), increased locomotor activity, improved body wall muscle mitochondrial content, and alleviated oxidative damage in C. elegans. These findings suggested that AU can ameliorate aging-related muscle atrophy and show significant potential in preventing and treating muscle atrophy.

Associations between kidney function with all-cause and cause-specific mortality in type 2 diabetes mellitus patients: a prospective cohort study in China

BACKGROUND

Abnormal kidney function is associated with adverse outcomes in patients with type 2 diabetes mellitus (T2DM). However, the evidence between kidney function and mortality among Chinese patients with T2DM were still limited.

METHODS

This cohort study included 19,919 participants with baseline T2DM from 2013 to 2014 in Jiangsu, China. Serum estimated glomerular filtration rate (eGFR), urea, and uric acid were measured at baseline, and Cox regression models were used to evaluate hazard ratios (HRs) and 95% confidential intervals (95%CIs) of all-cause and cause-specific mortality. Restricted cubic splines were used to analyze dose-response relationships, and we explored the best cut-off values by receiver operating characteristic (ROC) curves.

RESULTS

During a median follow-up of 9.77 years, 4,428 deaths occurred, including 1,542 (34.8%) due to cardiovascular disease (CVD), and 1,074 (24.3%) due to cancer. Compared to lowest quintile level (Q1), the highest quintile (Q5) of eGFR was negatively associated with all-cause (HR = 0.67, 95%CI: 0.58-0.77) and CVD mortality (HR = 0.57, 95%CI = 0.44-0.75). The higher levels of urea and uric acid were positively associated with all-cause mortality (Q5 vs. Q1: HR = 1.27, 95%CI: 1.16-1.39; HR = 1.21, 95%CI: 1.10-1.34), with an overall "U-shaped" dose-response relationships. Moreover, higher urea was negatively associated with cancer mortality (Q5 vs. Q1: HR = 0.79, 95%CI: 0.66-0.95). The best cut-off values with all-cause mortality were 88.50 ml/min/1.73m2, 6.95 mmol/L and 342.50 µmol/L for eGFR, urea, and uric acid, respectively.

CONCLUSION

We found abnormal kidney function was associated with mortality among people with T2DM. More clinical researches are needed to validate the effects and cut-off values of kidney function on mortality risk for T2DM prevention and management.

Oxidative balance score is associated with increased risk of sarcopenia and sarcopenic obesity in non-elderly adults: results from NHANES 2011-2018

BACKGROUND

Sarcopenia and obesity, two prevalent health conditions, often coexist and exacerbate each other's impact, increasing the risk of chronic diseases and mortality. This dual condition is termed "sarcopenic obesity." The correlation between oxidative stress (OS) and sarcopenia or obesity was established, and the oxidative balance score (OBS) can serve as an indicator of overall dietary or lifestyle-related OS exposure within an individual. Prior reports have not addressed the relationship between OBS and sarcopenia or sarcopenic obesity in adults under 60. This study endeavors to explore these associations and to identify potential dietary and lifestyle risk factors.

METHODS

We performed a cross-sectional analysis utilizing data from 4,241 participants in the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2018. OBS is a cumulative score derived from 16 dietary components and 4 lifestyle components, where higher scores indicate greater exposure to antioxidants and lower exposure to pro-oxidant factors, reflecting a reduced oxidative stress burden. Weighted multivariate logistic regression was employed to investigate the association of OBS and sarcopenia and sarcopenic obesity. Further subgroup analyses was conducted to examine interactions with various covariates. The least absolute shrinkage and selection operator (LASSO) regression was applied to identify significant components of OBS associated with sarcopenia and sarcopenic obesity, which were subsequently integrated into a risk prediction nomogram model. The model's predictive accuracy was evaluated using the receiver operating characteristic (ROC) curve.

RESULTS

After adjusting for potential confounders, the weighted logistic regression analyses demonstrated a significant negative association between OBS and the prevalence of sarcopenia (odds ratio [OR] = 0.954, 95% confidence interval [CI] = 0.925-0.984, P = 0.004) and sarcopenic obesity (OR = 0.948, 95% CI = 0.918-0.980, P = 0.002). The nomogram models, informed by key OBS components identified through LASSO regression, exhibited considerable predictive value for sarcopenia (area under the ROC curve [AUC] = 0.813, 95% CI = 0.792-0.833) and sarcopenic obesity (AUC = 0.894, 95% CI = 0.879-0.909).

CONCLUSION

This study reveals a robust inverse correlation between OBS and both sarcopenia and sarcopenic obesity in adults aged 20-59. These results suggest that an antioxidant-rich diet and healthy lifestyle practices, including low-fat diets, adequate vitamin B intake, regular physical activity, and weight management, may help mitigate the risk of sarcopenia and sarcopenic obesity. Further research is warranted to confirm these associations and determine causality.

Impact of Hospitalization on Sarcopenia, NADPH-Oxidase 2, Oxidative Stress, and Low-Grade Endotoxemia in Elderly Patients

BACKGROUND

Hospitalization in older adults often worsens sarcopenia due to prolonged bed rest, poor nutrition, and inactivity. This study examined how hospitalization impacts muscle mass, focusing on oxidative stress and gut-derived endotoxemia.

METHODS

Thirty-one hospitalized older adults were compared with 31 outpatients. Ultrasound was used to measure the thickness of the rectus femoris (RF), intercostal, and diaphragmatic muscles at admission and discharge. Serum levels of LPS, zonulin, sNOX2-dp, and H2O2 were also assessed.

RESULTS

Hospitalized patients had higher serum levels of sNOX2-dp, H2O2, LPS, and zonulin than outpatients. In hospitalized patients, significant increases were observed at discharge compared to admission levels in sNOX2-dp (20.9 ± 6.5 to 23.8 ± 7.5 pg/mL; p = 0.004), H2O2 (24.4 ± 9.8 to 32.8 ± 14.5 µM; p = 0.01), LPS (30.4 ± 12.6 to 43.3 ± 16.35 pg/mL; p < 0.001), and zonulin (2.06 ± 1.23 to 2.95 ± 1.33 ng/mL; p < 0.001). Ultrasound data revealed a reduction in RF muscle thickness (-35%) (0.58 ± 0.29 to 0.38 ± 0.31 cm, p < 0.001), intercostal muscle thickness (-28%) (0.22 ± 0.08 to 0.16 ± 0.06 cm, p < 0.001), and diaphragmatic muscle thickness (-26%) (0.19 ± 0.06 to 0.14 ± 0.04 cm, p < 0.001) at discharge compared to admission. Additionally, muscle strength, measured using the hand-grip test, showed a 25% reduction. Regression analysis revealed correlations between RF muscle loss and increases in sNOX2-dp and H2O2, as well as between NOX2, H2O2, and LPS with zonulin.

CONCLUSIONS

Hospitalization in older adult patients elevates NOX2 blood levels, correlating with reduced muscle mass. Increased low-grade endotoxemia may trigger NOX2 activation, generating oxidative stress that accelerates muscle degeneration and can lead to sarcopenia.

Near Infrared-Mediated Intracellular NADH Delivery Strengthens Mitochondrial Function and Stability in Muscle Dysfunction Model

Mitochondrial transfer emerges as a promising therapy for the restoration of mitochondrial function in damaged cells, mainly due to its limited immunogenicity. However, isolated mitochondria rapidly lose function because they produce little energy outside cells. Therefore, this study investigates whether near infrared (NIR)-mediated nicotinamide adenine dinucleotide (NADH) pre-treatment enhances mitochondrial function and stability in mitochondria-donor cells prior to transplantation. Clinical applications of NADH, an essential electron donor in the oxidative phosphorylation process, are restricted due to the limited cellular uptake of NADH. To address this, a photo-mediated method optimizes direct NADH delivery into cells and increases NADH absorption. L6 cells treated with NADH and irradiated with NIR enhanced NADH uptake, significantly improving mitochondrial energy production and function. Importantly, the improved functional characteristics of the mitochondria are maintained even after isolation from cells. Primed mitochondria, i.e., those enhanced by NIR-mediated NADH uptake (P-MT), are encapsulated in fusogenic liposomes and delivered into muscle cells with mitochondrial dysfunction. Compared to conventional mitochondria, P-MT mitochondria promote greater mitochondrial recovery and muscle regeneration. These findings suggest that NIR-mediated NADH delivery is an effective strategy for improving mitochondrial function, and has the potential to lead to novel treatments for mitochondrial disorders and muscle degeneration.

Treatment of Denervated Muscle Atrophy by Injectable Dual-Responsive Hydrogels Loaded with Extracellular Vesicles

Denervated muscle atrophy, a common outcome of nerve injury, often results in irreversible fibrosis due to the limited effectiveness of current therapeutic interventions. While extracellular vesicles (EVs) offer promise for treating muscle atrophy, their therapeutic potential is hindered by challenges in delivery and bioactivity within the complex microenvironment of the injury site. To address this issue, an injectable hydrogel is developed that is responsive to both ultrasound and pH, with inherent anti-inflammatory and antioxidant properties, designed to improve the targeted delivery of stem cell-derived EVs. This hydrogel system allows for controlled release of EVs from human umbilical cord mesenchymal stem cells (HUC-MSCs), adapting to the specific conditions of the injury environment. In vivo studies using a rat model of nerve injury demonstrated that the EV-loaded hydrogel (EVs@UR-gel) significantly preserved muscle function. Six weeks post-nerve reconstruction, treated rats exhibited muscle strength, circumference, and wet weight reaching 89.53 ± 0.96%, 76.02 ± 7.49%, and 88.0 ± 2.65% of healthy controls, respectively, alongside an improvement in the sciatic nerve index (-0.11 ± 0.09). This platform presents a novel therapeutic approach by maintaining EV bioactivity, enabling tunable release based on the disease state, and facilitating the restoration of muscle structure and function.

The Protective Effects of Perch Essence Against Muscle Atrophy in Cancer Cachexia and Cisplatin Treatment

Muscle atrophy, through several pathways including increased protein catabolism, leads to adverse effects in cachexia induced by cancer and chemotherapy. Perch essence (PE) is a perch extract rich in branched-chain amino acids and peptides. The present study initially investigated the effects of PE supplementation on muscle atrophy in a mouse model of cancer cachexia induced by C26 cancer cells and compared these effects with those of tryptone. Compared with the tumor-only group, we found that PE supplementation significantly improved body weight, muscle mass, maximum limb grip strength (MLGS), and myosin heavy chain expression in the muscles of tumor-bearing mice. PE also significantly inhibited the expression of factors related to protein degradation, oxidative stress, and inflammation, while enhancing the expression of antioxidant enzymes in tumor-bearing mice. These effects of PE were associated with an increased expression of phosphorylated Akt and forkhead box protein O1, along with a reduced expression of phosphorylated nuclear factor-κB p65 in the muscles of tumor-bearing mice. Furthermore, PE similarly increased MLGS and attenuated muscle atrophy in mice exposed to cisplatin by inhibiting protein degradation. All the therapeutic effects of PE supplementation mentioned above were generally greater than those of tryptone supplementation. These results suggest the potential of PE in protecting against muscle atrophy induced by tumors or chemotherapy.

Stem cell therapy: A promising therapeutic approach for skeletal muscle atrophy

Skeletal muscle atrophy results from disruptions in the growth and metabolism of striated muscle, leading to a reduction or loss of muscle fibers. This condition not only significantly impacts patients’ quality of life but also imposes substantial socioeconomic burdens. The complex molecular mechanisms driving skeletal muscle atrophy contribute to the absence of effective treatment options. Recent advances in stem cell therapy have positioned it as a promising approach for addressing this condition. This article reviews the molecular mechanisms of muscle atrophy and outlines current therapeutic strategies, focusing on mesenchymal stem cells, induced pluripotent stem cells, and their derivatives. Additionally, the challenges these stem cells face in clinical applications are discussed. A deeper understanding of the regenerative potential of various stem cells could pave the way for breakthroughs in the prevention and treatment of muscle atrophy.

hBMSC-EVs alleviate weightlessness-induced skeletal muscle atrophy by suppressing oxidative stress and inflammation

BACKGROUND

Muscle disuse and offloading in microgravity are likely the primary factors mediating spaceflight-induced muscle atrophy, for which there is currently no effective treatment other than exercise. Extracellular vesicles derived from bone marrow mesenchymal stem cells (BMSC-EVs) possess anti-inflammatory and antioxidant properties, offering a potential strategy for combating weightless muscular atrophy.

METHODS

In this study, human BMSCs-EVs (hBMSC-EVs) were isolated using super-centrifugation and characterized. C2C12 myotube nutrition-deprivation and mice tail suspension models were established. Subsequently, the diameter of C2C12 myotubes, Soleus mass, cross-sectional area (CSA) of muscle fibers, and grip strength in mice were assessed to investigate the impact of hBMSC-EVs on muscle atrophy. Immunostaining, transmission electron microscopy observation, and western blot analysis were employed to assess the impact of hBMSC-EVs on muscle fiber types, ROS levels, inflammation, ubiquitin-proteasome system activity, and autophagy lysosome pathway activation in skeletal muscle atrophy.

RESULTS

The active hBMSC-EVs can be internalized by C2C12 myotubes and skeletal muscle. hBMSC-EVs can effectively reduce C2C12 myotube atrophy caused by nutritional deprivation, with a concentration of 10 × 108 particles/mL showing the best effect (P < 0.001). Additionally, hBMSC-EVs can down-regulate the protein levels associated with UPS and oxidative stress. Moreover, intravenous administration of hBMSC-EVs at a concentration of 1 × 1010 particles/mL can effectively reverse the reduction in soleus mass (P < 0.001), CSA (P < 0.01), and grip strength (P < 0.001) in mice caused by weightlessness. They demonstrate the ability to inhibit protein degradation mediated by UPS and autophagy lysosome pathway, along with the suppression of oxidative stress and inflammatory responses. Furthermore, hBMSC-EVs impede the transition of slow muscle fibers to fast muscle fibers via upregulation of Sirt1 and PGC-1α protein levels.

CONCLUSIONS

Our findings indicate that hBMSC-EVs are capable of inhibiting excessive activation of the UPS and autophagy lysosome pathway, suppressing oxidative stress and inflammatory response, reversing muscle fiber type transformation, effectively delaying hindlimb unloading-induced muscle atrophy and enhancing muscle function. Our study has further advanced the understanding of the molecular mechanism underlying muscle atrophy in weightlessness and has demonstrated the protective effect of hBMSC-EVs on muscle atrophy.

Ursolic Acid Restores Redox Homeostasis and Pro-inflammatory Cytokine Production in Denervation-Induced Skeletal Muscle Atrophy

Skeletal muscle (SkM) atrophy results from metabolic disorders causing body and muscle mass loss, affecting morbidity and mortality. Increased oxidative stress, inflammation, and poor prognosis are the leading causes of involuntary weight loss. Ursolic acid (UA), known for its antioxidant and anti-inflammatory properties, can potentially reduce oxidative stress and inflammation in muscles, but its effects on muscle mass regulation are still unknown. Therefore, the present study investigated the medicinal efficacy of UA and its mode of action against the murine model of SkM atrophy over 7 days of UA supplementation. Denervation-induced SkM atrophy significantly impacts overall body weight and the weight of individual muscles (p < 0.05). However, supplementation with UA can effectively counteract these effects by promoting the synthesis of the slow-myosin heavy chain, thereby restoring body weight and myotube diameter. Moreover, UA also plays a crucial role in reducing the production levels of reactive oxygen species (ROS), lipid peroxidation (LPO), and caspase-3-like activity in atrophied muscles. UA also prevents the leakage of creatine kinase (CK) through the upregulation of superoxide dismutase (SOD) and glutathione peroxidase (GPx) expression. Furthermore, the results obtained from qRT-PCR demonstrated a significant decrease in the levels of pro-inflammatory markers, namely IL-1β, IL-6, TNF-α, and TWEAK, up to four-fold after the third day of the UA intervention. UA also upregulated PGC-1α, Bcl2, and p-Aktser473 expression towards the regulation of redox homeostasis.

Utilizing zebrafish models to elucidate mechanisms and develop therapies for skeletal muscle atrophy

Skeletal muscle atrophy, resulting from an imbalance in muscle protein synthesis and degradation, compromises muscle quality and function, imposing significant burdens on movement and metabolic stability. Animal models are crucial for understanding the mechanisms of skeletal muscle atrophy and developing clinical prevention and treatment strategies. Zebrafish, as small aquatic vertebrates, exhibit high genetic homology with humans and offer advantages such as rapid reproduction, development, and transparent embryos. Their physiological and anatomical similarities to mammals, including a substantial proportion of skeletal muscle and observable swimming behavior reflecting body dysfunction, make zebrafish an ideal model for studying skeletal muscle-related diseases. This review outlines the development of zebrafish skeletal muscle and highlights key pathways regulating muscle proteins, emphasizing their anatomical and genetic consistency with humans. Various zebrafish models of skeletal muscle atrophy created through physical, chemical, and gene-editing methods are systematically summarized. Current challenges and proposed improvement strategies are also discussed to enhance the reliability and applicability of zebrafish models, providing a comprehensive reference for advancing research on skeletal muscle atrophy.

Standardized Boesenbergia pandurata Extract Prevents Dexamethasone-Induced Muscle Atrophy and Dysfunction in C57BL/6 Mice

Muscle atrophy, characterized by diminished muscle mass and impaired function, poses a substantial global health concern. Boesenbergia pandurata (Roxb.) Schltr., commonly known as fingerroot, possesses a variety of advantageous activities, including anti-inflammatory, antioxidant, antibacterial, and anticancer effects. However, there are currently no preclinical studies available that explore the potential of B. pandurata extract (BPE) to mitigate muscle atrophy. In this study, we aimed to explore the protective effects of BPE, standardized to panduratin A content, against muscle atrophy and its underlying molecular mechanisms in a dexamethasone-induced muscle atrophy mouse model. Compared with the dexamethasone group, BPE significantly restored muscle mass, muscle volume, muscle fiber cross-sectional area, grip strength, and exercise endurance. Additionally, BPE suppressed inflammatory responses by downregulating the expressions of nuclear factor kappa B and inflammatory cytokines while also enhancing antioxidant effects by increasing the expressions of antioxidant enzymes. Moreover, BPE promoted protein synthesis and muscle differentiation by stimulating the phosphatidylinositol 3-kinase/Akt/mammalian target of rapamycin signaling pathway. Furthermore, it suppressed myostatin expression and inhibited the expressions of E3 ubiquitin ligases by preventing the nuclear translocation of forkhead box O3a, thereby alleviating proteolysis. Overall, BPE effectively regulates unbalanced protein metabolism, suggesting its potential as a functional food ingredient for preventing muscle wasting diseases.

Effects of antioxidant nutrients on muscle mass, strength and function in COPD patients: A meta-analysis of randomized controlled trials

AIM

To comprehensively investigate the effects of antioxidant nutrients on muscle mass, strength and function in chronic obstructive pulmonary disease (COPD) patients.

METHODS

PubMed, Embase, Cochrane Library, and Web of Science were comprehensively searched from the inception to January 3, 2024. The quality of randomized controlled trials (RCTs) was measured using the Jadad scale. Weighted mean differences (WMDs) and 95% confidence intervals (CIs) were used as the effect size for measurement data. Further, subgroup analysis was conducted based on whether patients participated in lung rehabilitation plans while receiving nutritional interventions. Sensitivity analysis was performed on all outcomes.

RESULTS

A total of 12 studies involving 595 patients with COPD were included, with 11 studies had high quality, and one study had low quality. For muscle mass, patients receiving antioxidant nutrients had a significantly increased lean body mass index compared with those not receiving antioxidant nutrients (pooled WMD: 0.903, 95% CI: 0.264, 1.541, P = 0.006). For patients who did not participate in lung rehabilitation plan while receiving nutritional interventions, antioxidant nutrients brought about a significantly higher lean body mass index (pooled WMD: 1.360, 95% CI: 0.560, 2.160, P = 0.001). For muscle strength, patients in the antioxidant nutrient intervention group had significantly higher hand grip strength (HGS) than those in the non-antioxidant nutrient intervention group (pooled WMD: 1.976, 95% CI: 1.337, 2.615, P < 0.001). Patients receiving antioxidant nutrients had significantly greater inspiratory muscle strength (MIP) than those not receiving antioxidant nutrients (pooled WMD: 8.127, 95% CI: 2.677, 13.577, P = 0.003).

CONCLUSION

Antioxidant nutrient intervention significantly improved HGS, MIP and lean body mass index in COPD. Clinicians should consider increasing food intake or supplementation rich in antioxidants in the treatment plan of patients with COPD.

Repairing muscle with broccoli-derived sulforaphane: A preclinical evaluation for the treatment of mitochondrial myopathies

Skeletal muscle health relies on the production of adenosine triphosphate (ATP) in the mitochondria. ATP production is accompanied by oxidative phosphorylation, which generates reactive oxygen species (ROS). When there is an imbalance in ROS levels, oxidative stress and subsequent mitochondrial dysfunction, mitochondrial myopathies including sarcopenia, chronic progressive external ophthalmoplegia, and proximal myopathy can result. Such incurable myopathies are characterised by aberrant metabolism, limited ATP production, and muscle atrophy. Broccoli-derived sulforaphane has emerged as a novel treatment for mitochondrial myopathies because of its antioxidant and anti-inflammatory properties. This review discusses preclinical studies that reveal sulforaphane's potential therapeutic benefits and limitations in treating mitochondrial myopathies.

Polygonatum sibiricum polysaccharide ameliorates skeletal muscle aging and mitochondrial dysfunction via PI3K/Akt/mTOR signaling pathway

BACKGROUND

Sarcopenia is currently a life-threatening disease for the elderly. Polygonatum sibiricum polysaccharide (PSP) has anti-oxidative stress and anti-inflammatory effects. However, the effects of PSP on skeletal muscle aging, myoblast differentiation and mitochondrial dysfunction through PI3K/Akt/mTOR signaling pathway has not been explored.

PURPOSE

To explore the effects and related mechanisms of PSP on muscle aging, myoblast differentiation and mitochondrial dysfunction.

METHODS

The chemical components of Polygonatum sibiricum were determined using the UHPLC-MS/MS method. The common targets and biological pathways between PSP and sarcopenia were investigated by network pharmacology analysis. In vitro C2C12 cells experiments were performed to reveal the effects of PSP on muscle aging, myotube differentiation, and mitochondrial damage. In addition, in vivo experiments were designed with the mouse model of D-gal-induced aging to evaluate the ameliorative impact of PSP on the skeletal muscle mass and function.

RESULTS

Polygonatum sibiricum mainly included 466 bioactive components. Polygonatum sibiricum and sarcopenia had 278 common targets by network pharmacology analysis, which were associated with mitochondrial function and PI3K/Akt/mTOR pathway. In vitro experiment indicated that PSP significantly enhanced the viability of C2C12 cells and myotube differentiation by down-regulating p21, p53, p16, MuRF1 and Atrogin-1and up-regulating MyoD, Myogenin, and MyHC. However, the addition of LY294002, PI3K/Akt/mTOR pathway inhibitor, partially reversed the anti-aging and anti-oxidative stress effects of PSP. PSP also significantly improved mitochondrial membrane potential and decreased mitochondrial ROS levels by upregulating the phosphorylation of the PI3K/Akt/mTOR pathway. In vivo experimental data indicated that PSP significantly enhanced muscle strength, endurance, mass of skeletal muscle (quadriceps and gastrocnemius) and cross-sectional area (CSA) of skeletal muscle in D-gal induced aging mice.

CONCLUSION

PSP exhibits significant ameliorative effects on skeletal muscle aging and atrophy, as well as mitochondrial dysfunction by activating the PI3K/Akt/mTOR signaling pathway. Our study uniquely investigates the effects of PSP on skeletal muscle aging and mitochondrial dysfunction with a specific focus on the PI3K/Akt/mTOR signaling pathway, which highlights the potential of PSP as a novel therapeutic agent for sarcopenia, offering an alternative to current treatment strategies.

Tuina alleviates the muscle atrophy induced by sciatic nerve injury in rats through regulation of PI3K/Akt signaling

BACKGROUND

Tuina is an effective treatment for the decrease of skeletal muscle atrophy after peripheral nerve injury. However, the underlying mechanism of action remains unclear. This study aimed to explore the underlying mechanisms of tuina in rats with sciatic nerve injury (SNI).

METHODS

We established an SNI rat model. After Tuina intervention, curative effects were evaluated by behavioral assessment, nerve function index, and muscle atrophy index (MAI). Pathological changes were observed by transmission electron microscopy and immunofluorescence. Insulin-like growth factor 1 (IGF-1), forkhead box O (FoxO) and p-FoxO levels were detected using enzyme-linked immunosorbent assay. Western blotting was performed to detect the expression of proteins involved in the PI3K/AKT signaling pathway.

RESULT

Behavioral assessment, nerve function index, and MAI revealed that the tuina had significantly improved muscle atrophy after SNI compared with the SNI model group. Transmission electron microscopy showed that tuina improved muscle ultramicrostructure. CD31 immunofluorescence revealed that tuina improved microcirculation. Furthermore, we observed that tuina differentially regulated the levels of IGF-1, FoxO and p-FoxO, and the protein expression of p-Phosphoinositide 3-kinase (p-PI3K), p-AKT, and vascular endothelial growth factor in the anterior tibial muscle and soleus muscles.

CONCLUSION

Tuina could effectively inhibit skeletal muscle atrophy via the microcirculation pathway in a rat model of SNI by regulating the expression of IGF-1 and FoxO. The underlying mechanism of action may involve the PI3K/Akt signaling pathway.

Novel tris-bipyridine based Ru(II) complexes as type-I/-II photosensitizers for antitumor photodynamic therapy through ferroptosis and immunogenic cell death

Ru(II) complexes have attracted attention as photosensitizers for their promising photodynamic properties. Herein, novel tris-bipyridine based Ru(II) complexes (6a-e) were synthesized by introducing saturated heterocycles to improve photodynamic properties and lipid-water partition coefficients. Among them, 6d demonstrated significant phototoxicity towards three cancer cells, with IC50 values of 5.66-7.17 μM, exceeding values in dark (IC50s > 100 μM). Under hypoxic conditions, 6d maintained excellent photodynamic activity in A549 cells, with PI values exceeding 24, highlighting its potential for highly effective type-I/-II photodynamic therapy by inducing ROS generation, oxidative stress, and mitochondrial damage. Additionally, it induced ferroptosis and immunogenic cell death of A549 cells by regulating the expression of relevant markers. Finally, 6d remarkably inhibited the growth of A549 transplanted tumor growth by 95.4 %. This Ru(II) complex shows great potential for cancer treatment with its potent photodynamic activity and diverse mechanisms of tumor cell death.

6'-sialyllactose prevents dexamethasone-induced muscle atrophy by controlling the muscle protein degradation pathway

Sarcopenia is associated with various geriatric diseases, such as gait disorders, falls, malnutrition, and osteoporosis. Accordingly, interest in the prevention and treatment of sarcopenia has grown over the years. The human milk oligosaccharide (HMO) 6'-sialyllactose (6'-SL) is known to improve exercise performance, reduce muscle fatigue, and improve GNE myopathy; however, its effect on sarcopenia has not yet been reported. In this study, we aimed to investigate the efficacy of 6'-SL in dexamethasone-induced muscle atrophy, which is a widely used model for the study of sarcopenia. The effects of 6'-SL on differentiated C2C12 skeletal muscle cells and on mice were examined by treatment with 6'-SL in the presence or absence of dexamethasone. 6'-SL was found to inhibit the dexamethasone-induced decrease of MHC expression, as well as to prevent reduction in the number, length, and width of myotubes. Furthermore, the dexamethasone-induced upregulation of myostatin, muscle RING-finger protein-1 (MuRF1), and atrogin-1 were also inhibited by 6'-SL treatment. In mice, intraperitoneal administration of dexamethasone caused decreases in muscle fiber diameter, muscle weight, and exercise performance, most of which were significantly inhibited by oral treatment with 6'-SL. Therefore, utilization of 6'-SL could contribute to the prevention and treatment of muscle atrophy and sarcopenia.

Revealing the key antioxidant compounds and potential action mechanisms of Chinese Cabernet Sauvignon red wines by integrating UHPLC-QTOF-MS-based untargeted metabolomics, network pharmacology and molecular docking approaches

In recent years, red wine drinking has become more popular in China owing to its antioxidant effects. However, the key antioxidant compounds and their action mechanisms of Chinese red wines are still unclear. Herein, the antioxidant activities and chemical compositions of 45 Chinese Cabernet Sauvignon red wine samples were determined using chemical antioxidant assays and an UHPLC-QTOF-MS-based untargeted metabolomics method. The key antioxidant compounds in red wines and potential action mechanisms were revealed by integrating network pharmacology and molecular docking approaches. Results showed that there are 8 key antioxidant compounds in the red wine samples. These compounds are involved in several metabolic pathways in the body, particularly PI3K/AKT. What's more, they bind to the core antioxidant targets through hydrogen bonding and hydrophobic interaction. Among them, myricetin, laricitrin, 2,3,8-tri-O-methylellagic acid and AKT1 have the highest binding energies. This study could provide the theoretical basis for further investigation of physiological activities and functions of Chinese red wines.

Platelet-rich plasma ameliorates dexamethasone-induced myopathy by suppressing autophagy and enhancing myogenic potential through modulation of Myo-D, Pax-7, and myogenin expression

BACKGROUND

Muscle tissue is essential for overall well-being that declines with age and different illnesses. Glucocorticoids, despite being efficient in treating inflammation, can induce muscle weakness (known as glucocorticoid-induced myopathy) by affecting protein breakdown and synthesis. Glucocorticoids have a negative impact on satellite cells, which play a role in muscle regeneration. Platelet rich plasma (PRP), containing concentrated growth factors, has a potential role in enhancing tissue repair and could be used to ameliorates combat muscle wasting caused by glucocorticoids.

AIM

The purpose of this study was to identify how PRP can affect dexamethasone-induced myopathy in a rat model.

METHODS

Twenty-four male rats were divided into four equal groups: control, PRP, steroid (dexamethasone) treated for induction of myopathy, and steroid then treated with PRP for three weeks. Skeletal muscle contractile properties, protein content of the muscle, oxidative stress markers, histological structure, myogenin gene expression and immunohistochemical expression of Myo-D, Pax-7 and LC3 were assessed.

RESULTS

dexamethasone caused significant muscle weakness, decreased protein content, increased oxidative stress, decreased expression of myogenic genes and upregulated LC3 expression. PRP administration significantly improved muscle function, increased protein content, reduced oxidative stress, and upregulated myogenic genes. Histological results confirmed these findings. Additionally, PRP decreased autophagy marker LC3 expression and increased muscle stem cell markers MyoD and Pax7.

CONCLUSION

These results suggested that PRP could effectively prevent and reverse dexamethasone-induced muscle atrophy by promoting muscle protein synthesis, reducing oxidative stress, decreasing autophagy, and enhancing muscle stem cell activity. This study supports the potential role of PRP as a therapeutic strategy for muscle wasting disorders.

Lin28a forms an RNA-binding complex with Igf2bp3 to regulate m6A-modified stress response genes in stress granules of muscle stem cells

In the early embryonic stages, Lin-28 homologue A (Lin28a) is highly expressed and declines as the embryo matures. As an RNA-binding protein, Lin28a maintains some adult muscle stem cells (MuSCs) in an embryonic-like state, but its RNA metabolism regulation mechanism remains unclear. BioGPS analysis revealed that Lin28a expression is significantly higher in muscle tissues than in other tissues. Lin28a-positive muscle stem cells (Lin28a+ MuSCs) were sorted from Lin28a-CreERT2; LSL-tdTomato mouse skeletal muscle tissue, which exhibited a higher proliferation rate than the control group. Lin28a-bound transcripts are enriched in various biological processes such as DNA repair, cell cycle, mitochondrial tricarboxylic acid cycle and oxidative stress response. The expression of insulin-like growth factor 2 mRNA-binding protein 3 (Igf2bp3) was markedly elevated in the presence of Lin28a. Co-immunoprecipitation analysis further demonstrated that Lin28a associates with Igf2bp3. Immunofluorescence analyses confirmed that Lin28a, Igf2bp3 and G3bp1 colocalize to form stress granules (SG), and N6-methyladenosine (m6A) modification promotes the formation of Lin28a-SG. Sequencing of the transcriptome and RNAs immunoprecipitated by Lin28a, Igf2bp3 and m6A antibodies in Lin28a+ MuSCs further revealed that Lin28a and Igf2bp3 collaboratively regulate the expression of DNA repair-related genes, including Fancm and Usp1. Lin28a stabilises Igf2bp3, Usp1, and Fancm mRNAs, enhancing DNA repair against oxidative or proteotoxic stress, thus promoting MuSCs self-renewal. Understanding the intricate mechanisms through which Lin28a and Igf2bp3 regulate MuSCs provides a deeper understanding of stem cell self-renewal, with potential implications for regenerative medicine.

Association between residual cholesterol and sarcopenia in American adults

Background

Remnant cholesterol (RC) is a novel lipid metabolism indicator; however, its relationship with sarcopenia has not been clearly established. This study was conducted to explore the association between RC and sarcopenia.

Methods

An analysis was performed utilizing cross-sectional data from the NHANES 2011-2018. The variable RC was subjected to a logarithmic transformation to address its skewness. Logistic regression studies were conducted to examine the association between RC and sarcopenia. This study used restricted cubic spline (RCS) and threshold saturation techniques to investigate nonlinear connections. Subgroup, sensitivity, and additional analyses were performed to assess the robustness and validity of the findings.

Results

The study included 4636 participants. Participants with sarcopenia had significantly higher RC levels. Logistic regression demonstrated a substantial positive association between the prevalence of sarcopenia and log RC (OR=1.69, 95% CI=1.32-2.17). RCS analysis revealed a nonlinear relationship, identifying a threshold at RC=25. When the RC is below this threshold, every one-unit increase in RC increases the chance of sarcopenia by 7% (OR=1.07, 95% CI=1.04-1.10); above this threshold, changes in RC were not significant. Subgroup analysis confirmed that RC was an independent risk factor for sarcopenia. The sensitivity and supplementary analyses supported the main findings.

Conclusion

This study demonstrates a significant positive association between RC levels and the prevalence of sarcopenia in U.S. adults, offering novel evidence that RC may serve as a valuable indicator for sarcopenia assessment.

Initial Glutathione Depletion During Short-Term Bed Rest: Pinpointing Synthesis and Degradation Checkpoints in the γ-Glutamyl Cycle

Hypokinesia triggers oxidative stress and accelerates the turnover of the glutathione system via the γ-glutamyl cycle. Our study aimed to identify the regulatory checkpoints controlling intracellular glutathione levels. We measured the intermediate substrates of the γ-glutamyl cycle in erythrocytes from 19 healthy young male volunteers before and during a 10-day experimental bed rest. Additionally, we tracked changes in glutathione levels and specific metabolite ratios up to 21 days of bed rest. Using gas chromatography-mass spectrometry and the internal standard technique, we observed a 9 ± 9% decrease in glutathione levels during the first 5 days of bed rest, followed by an 11 ± 9% increase from the 5th to the 10th day, nearly returning to baseline ambulatory levels. The cysteinyl-glycine-to-glutathione ratio, reflecting γ-glutamyl cyclotransferase activity (a key enzyme in glutathione breakdown), rose by 14 ± 22% in the first 5 days and then fell by 10 ± 14% over the subsequent 5 days, again approaching baseline levels. Additionally, the γ-glutamyl cysteine-to-cysteine ratio, indicative of γ-glutamyl cysteine synthetase activity (crucial for glutathione synthesis), increased by 12 ± 30% on day 5 and by 29 ± 41% on day 10 of bed rest. The results observed on day 21 of bed rest confirm those seen on day 10. By calculating the ratio of product concentration to precursor concentration, we assessed the efficiency of these key enzymes in glutathione turnover. These results were corroborated by directly measuring glutathione synthesis and degradation rates in vivo using stable isotope techniques. Our findings reveal significant changes in glutathione kinetics during the initial days of bed rest and identify potential therapeutic targets for maintaining glutathione levels.

Oral administration of plumbagin is beneficial in in vivo models of Duchenne muscular dystrophy through control of redox signaling

Duchenne muscular dystrophy (DMD) is a progressive muscle-wasting disease. Recently approved molecular/gene treatments do not solve the downstream inflammation-linked pathophysiological issues such that supportive therapies are required to improve therapeutic efficacy and patients' quality of life. Over the years, a plethora of bioactive natural compounds have been used for human healthcare. Among them, plumbagin, a plant-derived analog of vitamin K3, has shown interesting potential to counteract chronic inflammation with potential therapeutic significance. In this work we evaluated the effects of plumbagin on DMD by delivering it as an oral supplement within food to dystrophic mutant of the fruit fly Drosophila melanogaster and mdx mice. In both DMD models, plumbagin show no relevant adverse effect. In terms of efficacy plumbagin improved the climbing ability of the dystrophic flies and their muscle morphology also reducing oxidative stress in muscles. In mdx mice, plumbagin enhanced the running performance on the treadmill and the muscle strength along with muscle morphology. The molecular mechanism underpinning these actions was found to be the activation of nuclear factor erythroid 2-related factor 2 pathway, the re-establishment of redox homeostasis and the reduction of inflammation thus generating a more favorable environment for skeletal muscles regeneration after damage. Our data provide evidence that food supplementation with plumbagin modulates the main, evolutionary conserved, mechanistic pathophysiological hallmarks of dystrophy, thus improving muscle function in vivo; the use of plumbagin as a therapeutic in humans should thus be explored further.

Impact of Alpha-Ketoglutarate on Skeletal Muscle Health and Exercise Performance: A Narrative Review

AKG, a central metabolite in the Krebs cycle, plays a vital role in cellular energy production and nitrogen metabolism. This review explores AKG's potential therapeutic applications in skeletal muscle health and exercise performance, focusing on its mechanisms for promoting muscle regeneration and counteracting muscle atrophy. A literature search was conducted using the PubMed, Web of Science, and Scopus databases, yielding 945 articles published up to 31 October 2024. Of these, 112 peer-reviewed articles met the inclusion criteria and formed the basis of this review. AKG supports muscle recovery by stimulating muscle satellite cells (MuSCs) and macrophage polarization, aiding muscle repair and reducing fibrosis. Additionally, AKG shows promise in preventing muscle atrophy by enhancing protein synthesis, inhibiting degradation pathways, and modulating inflammatory responses, making it relevant in conditions like sarcopenia, cachexia, and injury recovery. For athletes and active individuals, AKG supplementation has enhanced endurance, reduced fatigue, and supported faster post-exercise recovery. Despite promising preliminary findings, research gaps remain in understanding AKG's long-term effects, optimal dosage, and specific pathways, particularly across diverse populations. Further research, including large-scale clinical trials, is essential to clarify AKG's role in muscle health and to optimize its application as a therapeutic agent for skeletal muscle diseases and an enhancer of physical performance. This review aims to provide a comprehensive overview of AKG's benefits and identify future directions for research in both clinical and sports settings.

Caffeine intake is nonlinearly associated with muscle mass in young and middle-aged US adults

BACKGROUND

Recent studies have indicated that coffee consumption is inversely correlated with sarcopenia in the elderly population. Data regarding the association between caffeine intake and muscle mass in young adults are scarce.

OBJECTIVE

We aimed to investigate how dietary caffeine correlates with muscle mass and sarcopenia in the young and middle-aged people.

METHODS

We performed a cross-sectional study utilizing data from NHANES. Muscle mass was evaluated using DXA and caffeine intake was derived from 24-h dietary recalls. Multivariable regression analysis was adopted to explore association between caffeine and sarcopenia. Restricted cubic spline analysis was conducted to investigate dose-response effect of dietary caffeine on muscle mass. Mediation effect of high-sensitivity C reactive protein was examined by mediation analysis.

RESULTS

A total of 9116 adults aged from 20 to 59 years old were included. Higher ingestion of caffeine was not associated with sarcopenia. Association between dietary caffeine and muscle mass was found to be W-shaped in males and U-shaped in young females, wherein mediation effect of hs-CRP was not discovered.

CONCLUSIONS

Caffeine consumption is associated with muscle mass in a nonlinear pattern. ASMI peaks at a daily caffeine intake of 1.23 mg/kg in young adults, while 0.64-1.49 mg/kg is recommended for middle-aged men.

Low Serum Beta-2 Microglobulin Level: A Possible Biomarker for Sarcopenia in the Elderly Population

Background and Objectives: One of the most critical problems regarding sarcopenia is the difficulty of the diagnosis process. This study aimed to determine the prevalence and investigate the role of serum beta-2 microglobulin level as a biomarker for diagnosing sarcopenia. Materials and Methods: This nested case-control study was conducted between 2023 and 2024 on 251 older adults. Muscle strength was measured using a hand dynamometer, and muscle mass was assessed using the bioelectrical impedance method. Individuals with low muscle strength and low muscle mass were accepted as having definitive sarcopenia. Results: The mean age of the 251 older adults included in the study was 72.19 ± 6.11 years. The prevalence of sarcopenia in individuals aged 65 years and over was found to be 5.2%. Serum beta-2 microglobulin levels were statistically significantly lower in sarcopenic participants compared to the control group (p = 0.002). The optimal cut-off value for serum beta-2 microglobulin level was 2.26 mcg/mL, and values lower than this point were found to be diagnostic for sarcopenia. Regarding the cut-off value, the sensitivity was 92.31% and the specificity was 80.77%, the positive predictive value was 70.59%, the negative predictive value was 95.45%, the Youden index was 0.731, and the area under the curve value was 0.901. Individuals who had beta-2 microglobulin levels below 2.26 mcg/mL were found to have a 10.75 times higher risk of sarcopenia. Conclusions: A low serum beta-2 microglobulin level has the potential to be an important candidate biomarker for the diagnosis of sarcopenia.

Scientific landscape of oxidative stress in sarcopenia: from bibliometric analysis to hotspots review

OBJECTIVE

Sarcopenia is a significant healthcare challenge in the aging population. Oxidative stress (OS) is acknowledged to play a pivotal role in the pathological progression of sarcopenia. Numerous studies have demonstrated that mitigating or eliminating OS can ameliorate the pathological manifestations associated with sarcopenia. However, current clinical antioxidant therapies often fall short of anticipated outcomes. This bibliometric analysis aims to delineate prevailing research trends, thematic emphases, focal points, and developmental trajectories within the domain of OS in sarcopenia, while also endeavoring to explore prospective anti-oxidative stress strategies for future clinical interventions.

METHODS

Relevant publications were retrieved from the Web of Science (WOS) Core Collection database for the period 2000-2024. Citespace was employed for retrieving and analyzing trends and emerging topics.

RESULTS

In the field of OS in sarcopenia, the number of publications has significantly increased from 2000 to 2024. The United States and China are the primary contributors to global publication output. The most productive research institution is INRAE. The most prolific author is Holly Van Remmen from the United States, while the most frequently cited author is Cruz-Jentoft AJ from Spain. Experimental Gerontology is the journal with the highest volume of published articles, whereas the Journal of Gerontology Series A: Biological Sciences and Medical Sciences holds the record for the highest number of citations. The research keywords in this field can be categorized into eight domains: "Physiology and anatomy", "Physiological mechanisms", "Pathology associations", "Experimental studies", "Nutrition and metabolism", "Sports and physical activities", "Age" and "Oxidation and antioxidation". Moreover, recent years have seen the emergence of "TNF-α," "insulin resistance", "mitochondrial autophagy", "signal pathways", and "mechanisms" as focal points in the realm of OS in sarcopenia, encompassing related fundamental research and clinical translation.

CONCLUSION

This bibliometric and visualization provides a comprehensive analysis of the global research landscape in the field of OS in sarcopenia, identifies priorities, summarizes the current research status and suggests possible future research priorities. In addition, in order to benefit more sarcopenia patients, strengthening cooperation and communication between institutions and research teams is the key to the future development of this field. Given the expectation that research on OS in sarcopenia will remain a prominent area of interest in the future, this article could serve as a valuable resource for scholars seeking to shape future studies through an understanding of influential scholarly contributions and key research findings.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk, identifier CRD42024528628.

Therapeutic potential of omaveloxolone in counteracting muscle atrophy post-denervation: a multi-omics approach

BACKGROUND

Muscle atrophy caused by denervation is common in neuromuscular diseases, leading to loss of muscle mass and function. However, a comprehensive understanding of the overall molecular network changes during muscle denervation atrophy is still deficient, hindering the development of effective treatments.

METHOD

In this study, a sciatic nerve transection model was employed in male C57BL/6 J mice to induce muscle denervation atrophy. Gastrocnemius muscles were harvested at 3 days, 2 weeks, and 4 weeks post-denervation for transcriptomic and proteomic analysis. An integrative multi-omics approach was utilized to identify key genes essential for disease progression. Targeted proteomics using PRM was then employed to validate the differential expression of central genes. Combine single-nucleus sequencing results to observe the expression levels of PRM-validated genes in different cell types within muscle tissue.Through upstream regulatory analysis, NRF2 was identified as a potential therapeutic target. The therapeutic potential of the NRF2-targeting drug Omaveloxolone was evaluated in the mouse model.

RESULT

This research examined the temporal alterations in transcripts and proteins during muscle atrophy subsequent to denervation. A comprehensive analysis identified 54,534 transcripts and 3,218 proteins, of which 23,282 transcripts and 1,852 proteins exhibited statistically significant changes at 3 days, 2 weeks, and 4 weeks post-denervation. Utilizing multi-omics approaches, 30 hubgenes were selected, and PRM validation confirmed significant expression variances in 23 genes. The findings highlighted the involvement of mitochondrial dysfunction, oxidative stress, and metabolic disturbances in the pathogenesis of muscle atrophy, with a pronounced impact on type II muscle fibers, particularly type IIb fibers. The potential therapeutic benefits of Omaveloxolone in mitigating oxidative stress and preserving mitochondrial morphology were confirmed, thereby presenting novel strategies for addressing muscle atrophy induced by denervation. GSEA analysis results show that Autophagy, glutathione metabolism, and PPAR signaling pathways are significantly upregulated, while inflammation-related and neurodegenerative disease-related pathways are significantly inhibited in the Omaveloxolone group.GSR expression and the GSH/GSSG ratio were significantly higher in the Omaveloxolone group compared to the control group, while MuSK expression was significantly lower than in the control group.

CONCLUSION

In our study, we revealed the crucial role of oxidative stress, glucose metabolism, and mitochondrial dysfunction in denervation-induced muscle atrophy, identifying NRF2 as a potential therapeutic target. Omaveloxolone was shown to stabilize mitochondrial function, enhance antioxidant capacity, and protect neuromuscular junctions, thereby offering promising therapeutic potential for treating denervation-induced muscle atrophy.

Elucidating the roles of SOD3 correlated genes and reactive oxygen species in rare human diseases using a bioinformatic-ontology approach

Superoxide Dismutase 3 (SOD3) scavenges extracellular superoxide giving a hydrogen peroxide metabolite. Both Reactive Oxygen Species diffuse through aquaporins causing oxidative stress and biomolecular damage. SOD3 is differentially expressed in cancer and this research utilises Gene Expression Omnibus data series GSE2109 with 2,158 cancer samples. Genome-wide expression correlation analysis was conducted with SOD3 as the seed gene. Categorical SOD3 Pearson Correlation gene lists incrementing in correlation strength by 0.01 from ρ≥|0.34| to ρ≥|0.41| were extracted from the data. Positively and negatively SOD3 correlated genes were separated for each list and checked for significance against disease overlapping genes in the ClinVar and Orphanet databases via Enrichr. Disease causal genes were added to the relevant gene list and checked against Gene Ontology, Phenotype Ontology, and Elsevier Pathways via Enrichr before the significant ontologies containing causal and non-overlapping genes were reviewed with a literature search for possible disease and oxidative stress associations. 12 significant individually discriminated disorders were identified: Autosomal Dominant Cutis Laxa (p = 6.05x10-7), Renal Tubular Dysgenesis of Genetic Origin (p = 6.05x10-7), Lethal Arteriopathy Syndrome due to Fibulin-4 Deficiency (p = 6.54x10-9), EMILIN-1-related Connective Tissue Disease (p = 6.54x10-9), Holt-Oram Syndrome (p = 7.72x10-10), Multisystemic Smooth Muscle Dysfunction Syndrome (p = 9.95x10-15), Distal Hereditary Motor Neuropathy type 2 (p = 4.48x10-7), Congenital Glaucoma (p = 5.24x210-9), Megacystis-Microcolon-Intestinal Hypoperistalsis Syndrome (p = 3.77x10-16), Classical-like Ehlers-Danlos Syndrome type 1 (p = 3.77x10-16), Retinoblastoma (p = 1.9x10-8), and Lynch Syndrome (p = 5.04x10-9). 35 novel (21 unique) genes across 12 disorders were identified: ADNP, AOC3, CDC42EP2, CHTOP, CNN1, DES, FOXF1, FXR1, HLTF, KCNMB1, MTF2, MYH11, PLN, PNPLA2, REST, SGCA, SORBS1, SYNPO2, TAGLN, WAPL, and ZMYM4. These genes are proffered as potential biomarkers or therapeutic targets for the corresponding rare diseases discussed.

Combination of transcriptomics and proteomics for analyzing potential biomarker and molecular mechanism underlying skeletal muscle atrophy

BACKGROUND

The skeletal muscle atrophy is prevalently occurred in numerous chronic disease complications. Despite its important clinical significance, there are currently no therapeutic drugs, so new biomarkers and molecular mechanisms need to be discovered urgently.

METHODS

Transcriptome and proteome sequencing data were collected from normal and skeletal muscle atrophic mice. The differentially expressed genes (DEGs) and proteins (DEPs) were analyzed. Applying PPI analysis to obtain overlapping genes and proteins, which were next subjected to GO and KEGG enrichment analysis. Combined analysis of transcriptomics and proteomics was performed to get key genes that were simultaneously found in GO and KEGG enrichment results. Subsequently, RT-qPCR and immunofluorescence were constructed to verify the expression of screened key genes.

RESULTS

By combination of transcriptomics, proteomics and RT-qPCR results, we identified 14 key genes (Cav1, Col3a1, Dnaja1, Postn, Ptges3, Cd44, Clec3b, Igfbp6, Lamc1, Alb, Itga6, Mmp2, Timp2 and Cd9) that were markedly different in atrophic mice. Single-gene GSEA and immunofluorescence suggested Cd9 was probably the biomarker for skeletal muscle atrophy.

CONCLUSIONS

Our study hinted that Cd9 was potential biomarker and may interfere with skeletal muscle atrophy through process of aerobic respiration, oxidative phosphorylation, and metabolism of amino acids and fatty acids.

SIGNIFICANCE

The present study holds the subsequent significance: Frist, we investigated biomarkers for skeletal muscle atrophy using multi-omics approach. A total of 14 genes were markedly different in skeletal muscle atrophic mice. We finally found Cd9 is a potential biomarker for skeletal muscle atrophy. Our work presents novel biomarkers and potential regulatory mechanisms for the early detection and intervention of muscle atrophy.

Integrative study of skeletal muscle mitochondrial dysfunction in a murine pancreatic cancer-induced cachexia model

Pancreatic ductal adenocarcinoma (PDAC), the most common pancreatic cancer, is a deadly cancer, often diagnosed late and resistant to current therapies. PDAC patients are frequently affected by cachexia characterized by muscle mass and strength loss (sarcopenia) contributing to patient frailty and poor therapeutic response. This study assesses the mechanisms underlying mitochondrial remodeling in the cachectic skeletal muscle, through an integrative exploration combining functional, morphological, and omics-based evaluation of gastrocnemius muscle from KIC genetically engineered mice developing autochthonous pancreatic tumor and cachexia. Cachectic PDAC KIC mice exhibit severe sarcopenia with loss of muscle mass and strength associated with reduced muscle fiber's size and induction of protein degradation processes. Mitochondria in PDAC atrophied muscles show reduced respiratory capacities and structural alterations, associated with deregulation of oxidative phosphorylation and mitochondrial dynamics pathways. Beyond the metabolic pathways known to be altered in sarcopenic muscle (carbohydrates, proteins, and redox), lipid and nucleic acid metabolisms are also affected. Although the number of mitochondria per cell is not altered, mitochondrial mass shows a twofold decrease and the mitochondrial DNA threefold, suggesting a defect in mitochondrial genome homeostasis. In conclusion, this work provides a framework to guide toward the most relevant targets in the clinic to limit PDAC-induced cachexia.

Advanced glycation end products promote ROS production via PKC/p47 phox axis in skeletal muscle cells

Advanced glycation end products (AGEs) are risk factors for various diseases, including sarcopenia. One of the deleterious effects of AGEs is the induction of abnormal reactive oxygen species (ROS) production in skeletal muscle. However, the underlying mechanism remains poorly understood. Therefore, the aim of this study was to elucidate how AGEs induce ROS production in skeletal muscle cells. This study demonstrated that AGEs treatment promoted ROS production in myoblasts and myotubes while PKC inhibitor abolished ROS production by AGEs stimulation. Phosphorylation of p47 phox by kinases such as PKCα is required to form the Nox2 complex, which induces ROS production. In this study, AGEs treatment promoted the phosphorylation of PKCα and p47 phox in myoblasts and myotubes. Our findings suggest that AGEs promote ROS production through the phosphorylation of PKCα and p47 phox in skeletal muscle cells.

Mechanism of denervation muscle atrophy mediated by Ach/p38/MAPK pathway in rats with erectile dysfunction caused by nerve injury

BACKGROUND

Peripheral nerve injury can result in penile cavernosal denervation muscle atrophy, a primary factor in nerve injury erectile dysfunction (NED). While acetylcholine (Ach) is integral to erectile function, its role and mechanisms in NED need further exploration.

OBJECTIVE

To investigate the inhibition of CCMSCs Apoptosis and Protein Degradation Pathway by Ach in NED rat model.

METHODS

We investigated changes in Ach secretion and receptor expression in an NED rat model, followed by the evaluation of apoptosis and ubiquitin proteasome activation in hypoxic Cavernous smooth muscle cells (CCMSCs) and their co-cultures with Schwann cells (SWCs), under Ach influence. Further, key pathways in NED were identified via high-throughput sequencing, focusing on the p38/MAPK signaling pathway. We examined gene alterations related to this pathway using hypoxic cell models and employed p38 inhibitors to verify protein changes. Our findings in vitro were then confirmed in the NED rat model.

RESULTS

Nerve injury led to reduced Ach receptors and associated gene expression. Experimentally, Ach was shown to counteract CCMSC apoptosis and muscle protein degradation via the p38/MAPK pathway. Inhibition of the Ach degradation pathway demonstrated a capacity to slow NED progression in vivo.

DISCUSSION AND CONCLUSION

Activation of Ach receptors may decelerate denervation-induced cavernosal muscle atrophy, suggesting a potential therapeutic approach for NED. This study highlights the crucial role of the Ach/p38/MAPK axis in the pathophysiology of penis smooth muscle atrophy and its broader implications in managing NED and male erectile dysfunction.

Loss of SELENOW aggravates muscle loss with regulation of protein synthesis and the ubiquitin-proteasome system

Sarcopenia is characterized by accelerated muscle mass and function loss, which burdens and challenges public health worldwide. Several studies indicated that selenium deficiency is associated with sarcopenia; however, the specific mechanism remains unclear. Here, we demonstrated that selenoprotein W (SELENOW) containing selenium in the form of selenocysteine functioned in sarcopenia. SELENOW expression is up-regulated in dexamethasone (DEX)-induced muscle atrophy and age-related sarcopenia mouse models. Knockout (KO) of SELENOW profoundly aggravated the process of muscle mass loss in the two mouse models. Mechanistically, SELENOW KO suppressed the RAC1-mTOR cascade by the interaction between SELENOW and RAC1 and induced the imbalance of protein synthesis and degradation. Consistently, overexpression of SELENOW in vivo and in vitro alleviated the muscle and myotube atrophy induced by DEX. SELENOW played a role in age-related sarcopenia and regulated the genes associated with aging. Together, our study uncovered the function of SELENOW in age-related sarcopenia and provides promising evidence for the prevention and treatment of sarcopenia.

The inverse associations between composite-dietary-antioxidant-index and sarcopenia risk in US adults

BACKGROUND

It remains unknown whether composite-dietary-antioxidant-index (CDAI) is associated with the risk of sarcopenia. This study investigated the association of CDAI with sarcopenia risk among general US adults.

METHODS

A total of 10,093 participants were enrolled in the National Health and Nutrition Examination Surveys (NHANES) from 6 survey cycles (2003-2004, 2005-2006, 2011-2012, 2013-2014, 2015-2016 and 2017-2018). Multivariate logistic regression was carried out to examine the relationship between CDAI and the risk of sarcopenia. Restricted cubic spline (RCS) curves were employed to analyze nonlinear relationships.

RESULTS

In a multi-variable logistic regression model adjusting for demographics, lifestyle, economic status and other dietary factors, higher CDAI score was related to a lower risk of sarcopenia among US adults. Compared the highest quartile of CDAI score with the lowest, the OR and 95%CI were 0.49 (0.31-0.75). Furthermore, the RCS demonstrated a linear dose-response relationship between CDAI and sarcopenia (P non-linearity=0.92). These results remained consistent across subgroups stratified by age, sex, physical activity, drinking status, body mass index (BMI), smoking habits, energy intake, and Healthy Eating Index (HEI) score. In addition, the favorable associations of CDAI were primarily attributed to Vitamin E intake.

CONCLUSION

A higher CDAI score was associated with a lower risk of sarcopenia. According to these results, a greater adherence to CDAI may benefit sarcopenia prevention in adults.

The association between oxidative balance score and muscular dystrophies

Introduction

This research utilized data from the NHANES 2011-2018 study to investigate the connection between the Oxidative Balance Score (OBS) and muscular dystrophies.

Methods

This study is a cross-sectional, observational, secondary analysis utilizing data from the NHANES 2011-2018. Spearman's correlation, chi-square tests, logistic regression, and restricted cubic spline plots were employed for statistical analyses.

Results

This association remained significant after adjustment for various demographic and medical history factors (For continuous OBS: crude model, odds ratio [OR], 0.95, 95% confidence interval [CI:] 0.94, 0.97, p < 0.001; Model 1, OR, 0.94, 95% CI: 0.92, 0.96, p < 0.001; Model 2, OR, 0.95, 95% CI: 0.93, 0.97, p < 0.001; Model 3, OR, 0.95, 95% CI: 0.93, 0.97, p < 0.001; In quartile Q4 vs. Q1: Crude model, OR, 0. 42, 95% CI: 0.26, 0.66, p < 0.001; Model 1, OR, 0.33, 95% CI: 0.21, 0.52, p < 0.001; Model 2, OR, 0.37, 95% CI: 0.23, 0.58, p < 0.001; Model 3, OR, 0.38, 95% CI: 0.23, 0.60, p < 0.001). Restricted cubic spline (RCS) analysis further supported this inverse relationship, suggesting that OBS values above 10 may confer protection against muscular dystrophies (p for overall <0.001, p for non-linear = 0.536). However, the relationship between OBS and muscular dystrophies was not statistically significant in the subgroups with education level below high school, presence of cancer, or diabetes (p = 0.735, p = 0.574, p = 0.409, respectively).

Conclusion

The study found a significant inverse correlation between the OBS and muscular dystrophies, suggesting that individuals with higher oxidative balance had a lower risk of developing muscular dystrophies. The study highlights the potential role of oxidative balance in muscular dystrophies prevention and management.