Mitochondrial Function and Reactive Oxygen/Nitrogen Species in Skeletal Muscle

Muscle-Derived Mitochondria as a Novel Therapy for Muscle Degeneration After Rotator Cuff Tears

BACKGROUND

Rotator cuff tears (RCTs) commonly lead to muscle atrophy, fatty infiltration, and fibrosis, resulting in pain, weakness, and impaired shoulder mobility. These pathological changes are often irreversible and pose substantial treatment challenges. The aim of this study was to evaluate the therapeutic potential of muscle-derived mitochondria (Mito) in mitigating muscle degeneration and fibrosis following RCTs.

METHODS

Sprague Dawley rats were assigned to 3 groups: sham surgery, RCTs treated with Mito, or RCTs treated with phosphate-buffered saline solution (PBS). Following RCTs, in vivo Mito or PBS treatments were administered to the supraspinatus muscles (SSPs) of the rats immediately and then biweekly for 12 weeks. Data were collected on muscle morphology, fibrosis, fatty infiltration, oxidative stress, mitochondrial function, macrophage phenotypes, and serum inflammatory cytokines. In vitro experiments included mitochondria tracking in bone marrow-derived macrophages (BMDMs), characterization of macrophage polarization, and inflammatory cytokine profiling.

RESULTS

Isolated mitochondria preserved their morphology and function. Mito treatment improved muscle wet weight (p < 0.0001) and fiber cross-sectional area (p < 0.0001) while reducing fibrosis (p < 0.0001) and fatty infiltration (p < 0.0001). It upregulated mitochondrial markers cytochrome c oxidase (COX IV) and translocase of outer mitochondrial membrane 20 (TOMM20) (p < 0.0001) and enhanced antioxidative activity, as shown by increased superoxide dismutase (SOD) activity (p < 0.0001), elevated glutathione peroxidase (GSH-PX) levels (p = 0.038), and decreased malondialdehyde (MDA) levels (p = 0.0002). Mitochondrial density and morphology were restored in SSPs after Mito treatment. Additionally, Mito treatment induced an anti-inflammatory macrophage phenotype and reduced pro-inflammatory cytokines in vivo and in vitro.

CONCLUSIONS

Mito treatment mitigated muscle degeneration, improved mitochondrial function, and fostered an anti-inflammatory environment through macrophage modulation, demonstrating its potential as a cell-free therapeutic strategy for RCT-related muscle pathologies.

CLINICAL RELEVANCE

Although this is a preclinical study, its approach offers a novel avenue for improving RCT treatment outcomes. However, further validation in large animal models is needed to address the translational applicability of these findings, given the inherent regenerative capacity of rodent muscles.

Regulating Sirtuin 3-mediated mitochondrial dynamics through vanillic acid improves muscle atrophy in cancer-induced cachexia

Cancer cachexia is a cancer-associated disease characterized by gradual body weight loss due to pathologic muscle and fat loss, but effective treatments are still lacking. Here, we investigate the possible effect of vanillic acid (VA), known for its antioxidant, anti-inflammatory, and anti-obesity effects, on mitochondria-mediated improvement of cancer cachexia. We utilized cachexia-like models using CT26 colon cancer and dexamethasone. VA improved representative parameters of cancer cachexia including body weight loss and increased serum intereukin-6 levels. VA also attenuated muscle loss in the tibialis anterior and gastrocnemius muscles, inhibited proteolytic markers including muscle RING-finger protein-1 (MURF1) and muscle atrophy F-box (MAFbx) and improved mitochondrial function through alteration of sirtuins 3 (SIRT3) and mitofusin 1 (MFN1). Importantly, silencing the SIRT3 gene abolished the effect of VA, indicating that SIRT3 is important in the mechanism of action of VA. Overall, we suggest using VA as a novel therapeutic agent that can fundamentally treat and recover muscle atrophy in cancer cachexia patients.

Loss of popdc3 Impairs Mitochondrial Function and Causes Skeletal Muscle Atrophy and Reduced Swimming Ability in Zebrafish

BACKGROUND

The Popeye domain containing 3 (POPDC3) protein is essential for the maintenance of skeletal muscle homeostasis. POPDC3 is a pathogenic variant gene of limb-girdle muscular dystrophy (LGMD), and its variants lead to LGMDR26. At the animal level, zebrafish larvae with popdc3 mutations develop tail curls and muscle atrophy. However, the mechanism of skeletal muscle atrophy induced by POPDC3 variants/loss remains unclear.

METHODS

Eight-month-old male WT and popdc3 mKO zebrafish were used for this research. Loli Track (Denwmark) and Loligo Swimming Respirometer were used to observe the zebrafish's swimming ability. The zebrafish skeletal muscle structure and cross-sectional area (CSA) were observed and counted by transmission electron microscopy (TEM), H&E and wheat germ agglutinin (WGA). Enriched genes and signalling pathways were analysed using RNA sequencing, and the effects of popdc3 mKO on zebrafish skeletal muscle mitochondrial respiration, biogenesis and dynamics were examined to investigate possible mechanisms.

RESULTS

The swimming ability of popdc3 mKO zebrafish was reduced, and as evidenced by the reluctance to move, fewer movement trajectories, the total distance travelled (p < 0.001), the average velocity of movement (p < 0.001), oxygen consumption (MO2) (p < 0.01), maximum oxygen consumption (MO2max) (p < 0.05), critical swimming speed (Ucrit) (p < 0.01) and relative swimming speed (Ucrit-r) (p < 0.01) were significantly decreased and increased of the exhaustive swimming time (p < 0.01). In addition, loss of popdc3 reduced zebrafish skeletal muscle weight (p < 0.001), muscle/body weight (p < 0.01), myofibre size and CSA (p < 0.01), increased protein degradation (ubiquitination and autophagy) (p < 0.05) and decreased protein synthesis (p < 0.05), suggesting that popdc3 deficiency induces zebrafish skeletal muscle atrophy. Further, popdc3 mKO zebrafish mitochondrial function is reduced, as evidenced by impaired mitochondrial respiration, decreased biogenesis and kinetic imbalance (p < 0.05).

CONCLUSIONS

POPDC3, a Popeye protein, plays an important role in controlling mitochondrial function and skeletal muscle mass and strength. Loss of popdc3 decreases mitochondrial respiration and mitochondrial biogenesis, disrupting kinetic homeostasis, which induces mitochondrial dysfunction and impaired protein turnover (reduced synthesis and increased degradation), leading to zebrafish skeletal muscle atrophy.

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.

3D bioprintable Mg2+-incorporated hydrogels tailored for regeneration of volumetric muscle loss

Rationale: Current therapeutic approaches for volumetric muscle loss (VML) face challenges owing to limited graft availability and insufficient bioactivity. Three-dimensional (3D) bioprinting has become an alternative technology for fabricating native tissue-mimetic grafts, allowing for tailored structures and complex designs. Methods: We developed an Mg2+-incorporated bioink composed of thiolated gelatin (GtnSH) and maleimide-conjugated gelatin (GtnMI) decorated with magnesium peroxide (MgO2), referred to as a GtnSH/GtnMI/MgO2 bioink. We designed in situ crosslinking between GtnSH and GtnMI to prepare cytocompatible bioink for 3D bioprinting of muscle mimetics. Results: The incorporated MgO2 particles provided oxygen supplementation and myogenic cues. In vitro assays demonstrated that C2C12 myoblasts encapsulated in the GtnSH/GtnMI/MgO2 bioink exhibited high viability, intrinsic proliferation rate, and increased expression of key myogenic markers. In vivo transplantation of the 3D bioprinted GtnSH/GtnMI/MgO2 constructs facilitated muscle mass restoration and M2 macrophage polarization. Additionally, they downregulate the activities of CD4+ and CD8+ lymphocytes, inducing a transition from the initial inflammatory to the restoration phase. Conclusion: The GtnSH/GtnMI/MgO2 bioink is a potential therapeutic strategy for enhancing myogenesis and skeletal muscle tissue regeneration.

Unraveling the role of gut microbiota and plasma metabolites in fibromyalgia: Insights from Mendelian randomization and dietary interventions

Fibromyalgia (FM) is a complex disorder characterized by chronic pain, fatigue, and functional impairments, with unclear pathological mechanisms. Gut microbiota and plasma metabolites have been implicated in FM, but their causal relationships remain unexplored. This study aims to assess the causal relationships between gut microbiota, plasma metabolites, and FM using Mendelian randomization (MR) analysis and to explore potential mediating mechanisms. Public genome-wide association study data were analyzed using bidirectional MR. Associations between gut microbiota, plasma metabolites, and FM were evaluated, and multivariable MR identified mediating metabolites. Results were validated with inverse variance weighted, MR-Egger, and weighted median methods, with metabolic pathway enrichment analysis for further insights. MR identified protective associations between FM and four taxa (family Enterobacteriaceae, genus Butyricicoccus, genus Coprococcus1, and order Enterobacteriales) and risk associations with genus Eggerthella and genus Ruminococcaceae UCG005. Additionally, 82 plasma metabolites linked to pathways such as caffeine metabolism, α-linolenic acid metabolism, GLP-1, and incretin regulation were associated with FM. Mediation analysis revealed Enterobacteriaceae and Enterobacteriales influenced FM risk through 2,3-dihydroxypyridine and palmitoylcholine. Personalized dietary interventions, such as limiting caffeine intake, increasing omega-3 fatty acid consumption, adopting a low glycemic index diet, and reducing the intake of high-oxalate foods, may effectively alleviate FM-related symptoms by modulating metabolic pathways, reducing inflammation, and mitigating oxidative stress. This study highlights the intricate interactions between the gut microbiota and metabolic pathways, providing critical scientific evidence and actionable targets for clinical interventions, dietary management, and precision medicine approaches in FM treatment.

A meta-analysis of the efficacy of physical exercise interventions on activities of daily living in patients with Alzheimer's disease

Objective

This study aimed to systematically review published randomized controlled trials on the effects of physical exercise on activities of daily living (ADL) in Alzheimer's patients through meta-analysis, thereby synthesizing existing evidence to provide scientific intervention recommendations for exercise prescriptions in Alzheimer's patients.

Methods

Based on strict literature inclusion and exclusion criteria, a systematic search was conducted in databases including PubMed and Web of Science from their inception to July 1, 2024. The Cochrane risk assessment tool was used to evaluate the design of randomized controlled trials. Studies reporting on physical exercise interventions for ADL in Alzheimer's patients were systematically identified. Subgroup analyses and meta-regression were performed to explore sources of heterogeneity.

Results

Nineteen articles, for analysis, providing 27 randomized controlled trials (RCTs). A random-effects model was used to calculate the effect size and 95% confidence interval for each independent study, and meta-analysis was performed using Stata 16.0 and RevMan 5.4 software. The results showed that physical exercise might significantly improve ADL in Alzheimer's patients (SMD = 0.33, 95% CI: 0.12-0.54, I 2 = 81.7%). Sensitivity analysis confirmed the robustness of the results (p > 0.05). Egger's test did not reveal significant publication bias (p = 0.145). Samples were divided into different subgroups based on intervention content, duration, frequency, and session length. Subgroup analysis based on intervention characteristics showed that resistance training or aerobic exercise (SMD = 0.83, 95% CI: 0.60-1.05), long-term interventions (>6 months, SMD = 0.31, 95% CI: 0.13-0.49), medium-frequency interventions (4-5 times per week, SMD=0.39, 95% CI: 0.23-0.55), and short-duration training ( ≤ 30 min, SMD = 0.96, 95% CI: 0.71-1.21) might be most effective in enhancing ADL in Alzheimer's patients. These improvements were not only statistically significant but also had substantial impact in clinical practice.

Conclusion

Resistance training or aerobic exercise lasting more than 6 months, 4-5 times per week, and lasting no more than 30 min per session may be most effective in improving ADLs in patients with Alzheimer's disease.

The sodium/ascorbic acid co-transporter SVCT2 distributes in a striated membrane-enriched domain at the M-band level in slow-twitch skeletal muscle fibers

BACKGROUND

Vitamin C plays key roles in cellular homeostasis, functioning as a potent antioxidant and a positive regulator of cell differentiation. In skeletal muscle, the vitamin C/sodium co-transporter SVCT2 is preferentially expressed in oxidative slow fibers. SVCT2 is up-regulated during the early fusion of primary myoblasts and decreases during initial myotube growth, indicating the relevance of vitamin C uptake via SVCT2 for early skeletal muscle differentiation and fiber-type definition. However, our understanding of SVCT2 expression and function in adult skeletal muscles is still limited.

RESULTS

In this study, we demonstrate that SVCT2 exhibits an intracellular distribution in chicken slow skeletal muscles, following a highly organized striated pattern. A similar distribution was observed in human muscle samples, chicken cultured myotubes, and isolated mouse myofibers. Immunohistochemical analyses, combined with biochemical cell fractionation experiments, reveal a strong co-localization of SVCT2 with intracellular detergent-soluble membrane fractions at the central sarcomeric M-band, where it co-solubilizes with sarcoplasmic reticulum proteins. Remarkably, electrical stimulation of cultured myofibers induces the redistribution of SVCT2 into a vesicular pattern.

CONCLUSIONS

Our results provide novel insights into the dynamic roles of SVCT2 in different intracellular compartments in response to functional demands.

Physical Exercise and the Gut Microbiome: A Bidirectional Relationship Influencing Health and Performance

Background/Objectives: The human gut microbiome is a complex ecosystem of microorganisms that can influence our health and exercise habits. On the other hand, physical exercise can also impact our microbiome, affecting our health. Our narrative review examines the bidirectional relationship between physical activity and the gut microbiome, as well as the potential for targeted probiotic regimens to enhance sports performance. Methods: We conducted a comprehensive literature review to select articles published up till January 2024 on the topics of physical exercise, sports, probiotics, and gut microbiota from major scientific databases, incorporating over 100 studies. Results: We found that the impact of physical activity on the gut microbiome varies with the type and intensity of exercise. Moderate exercise promotes a healthy immune system, while high-intensity exercise for a long duration can cause a leaky gut and consequent systemic inflammation, which may disrupt the microbial balance. Combining aerobic and resistance training significantly affects bacterial diversity, linked to a lower prevalence of chronic metabolic disorders. Furthermore, exercise enhances gut microbiome diversity, increases SCFA production, improves nutrient utilization, and modulates neural and hormonal pathways, improving gut barrier integrity. Our findings also showed probiotic supplementation is associated with decreased inflammation, enhanced sports performance, and fewer gastrointestinal disturbances, suggesting that the relationship between the gut microbiome and physical activity is mutually influential. Conclusions: The bidirectional relationship between physical activity and the gut microbiome is exemplified by how exercise can promote beneficial bacteria while a healthy gut microbiome can potentially enhance exercise ability through various mechanisms. These findings underscore the importance of adding potential tailored exercise regimens and probiotic supplementation that consider individual microbiome profiles into exercise programs.

Regimen on Dnaja3 haploinsufficiency mediated sarcopenic obesity with imbalanced mitochondrial homeostasis and lipid metabolism

BACKGROUND

Sarcopenic obesity is characterized by excess fat mass and diminished muscular mass/function. DNAJA3, a mitochondrial co-chaperone protein, plays a crucial role in skeletal muscle development. GMI, an immunomodulatory protein, promotes myogenic differentiation through DNAJA3 activation. This study aims to elucidate the physiological effects of muscular Dnaja3 haploinsufficiency on mitochondrial dysfunction and dysregulated lipid metabolism and to assess the efficacy of GMI in rescuing sarcopenic obesity both in vitro and in vivo.

METHODS

We generated mouse strain with Dnaja3 heterozygosity (HSA-Dnaja3f/+) specifically in skeletal muscle. The body weight, body composition, and locomotor activity of WT and HSA-Dnaja3f/+ mice were examined. The isolated skeletal muscles and primary myoblasts from the WT and HSA-Dnaja3f/+ mice, at young or old age, were utilized to study the molecular mechanisms, mitochondrial respiration and ROS level, mitochondrial proteomes, and serological analyses, respectively. To evaluate the therapeutic efficacy of GMI, both short-term and long-term GMI treatment were administrated intraperitoneally to the HSA-Dnaja3f/+ young (4 weeks old) or adult (3 months old) mice for a duration of either 1 or 6 months, respectively.

RESULTS

Muscular Dnaja3 heterozygosity resulted in impaired locomotor activity (P < 0.05), reduced muscular cross-sectional area (P < 0.0001), and up-regulation of lipogenesis (ACC2) and pro-inflammation (STAT3) in skeletal muscles (P < 0.05). Primary myoblasts from the HSA-Dnaja3f/+ mice displayed impaired mitochondrial respiration (P < 0.01) and imbalanced mitochondrial ROS levels. A systemic proteomic analysis of the purified mitochondria from the primary myoblasts was conducted to show the abnormalities in mitochondrial function and fatty acid metabolism (P < 0.0001). At age of 13 to 14 months, the HSA-Dnaja3f/+ mice displayed increased body fat mass (P < 0.001), reduced fat-free mass (P < 0.01), and impaired glucose and insulin tolerance (P < 0.01). The short-term GMI treatment improved locomotor activity (P < 0.01) and down-regulated the protein levels of STAT3 (P < 0.05), ACC2, and mitochondrial respiratory complex III (UQCRC2) (P < 0.01) via DNAJA3 activation. The long-term GMI treatment ameliorated fat mass accumulation, glucose intolerance, and systemic inflammation (AST) (P < 0.05) in skeletal muscle, while enhancing thermogenesis (UCP1) (P < 0.01) in eWAT. GMI treatment promoted myogenesis, enhanced oxygen consumption, and ameliorated STAT3 (P < 0.01) through DNAJA3 activation (P < 0.05) in vitro.

CONCLUSIONS

Muscular Dnaja3 haploinsufficiency dysregulates mitochondrial function and lipid metabolism then leads to sarcopenic obesity. GMI emerges as a therapeutic regimen for sarcopenic obesity treatment through DNAJA3 activation.

Metabolic differences in MSTN and FGF5 dual-gene edited sheep muscle cells during myogenesis

Dynamic metabolic reprogramming occurs at different stages of myogenesis and contributes to the fate determination of skeletal muscle satellite cells (MuSCs). Accumulating evidence suggests that mutations in myostatin (MSTN) have a vital role in regulating muscle energy metabolism. Here, we explored the metabolic reprogramming in MuSCs and myotube cells in MSTN and FGF5 dual-gene edited sheep models prepared previously, and also focused on the metabolic alterations during myogenic differentiation of MuSCs. Our study revealed that the pathways of nucleotide metabolism, pantothenate and CoA biosynthesis were weakened, while the unsaturated fatty acids biosynthesis were strengthened during myogenic differentiation of sheep MuSCs. The MSTN and FGF5 dual-gene editing mainly inhibited nucleotide metabolism and biosynthesis of unsaturated fatty acids in sheep MuSCs, reduced the number of lipid droplets in per satellite cell, and promoted the pentose phosphate pathway, and the interconversion of pentose and glucuronate. The MSTN and FGF5 dual-gene editing also resulted in the inhibition of nucleotide metabolism and TCA cycle pathway in differentiated myotube cells. The differential metabolites we identified can be characterized as biomarkers of different cellular states, and providing a new reference for MSTN and FGF5 dual-gene editing in regulation of muscle development. It may also provide a reference for the development of muscle regeneration drugs targeting biomarkers.

Small organic molecules containing amorphous calcium phosphate: synthesis, characterization and transformation

As the primary solid phase, amorphous calcium phosphate (ACP) is a pivotal precursor in cellular biomineralization. The intrinsic interplay between ACP and Howard factor underscores the significance of understanding their association for advancing biomimetic ACP development. While organic compounds play established roles in biomineralization, this study presents the synthesis of ACP with naturally occurring organic compounds (ascorbate, glutamate, and itaconate) ubiquitously found in mitochondria and vital for bone remodeling and healing. The developed ACP with organic compounds was meticulously characterized using XRD, FTIR, and solid-state 13C and 31P NMR. The morphological analysis revealed the characteristic spherical morphology with particle size close to 20 nm of all synthesized ACP variants. Notably, the type of organic compound strongly influences true density, specific surface area, particle size, and transformation. The in vitro analysis was performed with MC3T3-E1 cells, indicating the highest cell viability with ACP_ASC (ascorbate), followed by ACP_ITA (itaconate). The lowest cell viability was observed with 10 %w/v of ACP_GLU (glutamate); however, 1 %w/v of ACP_GLU was cytocompatible. Further, the effect of small organic molecules on the transformation of ACP to low crystalline apatite (Ap) was examined in Milli-Q® water, PBS, and α-MEM.

Hypoxia-Inducible Factor and Oxidative Stress in Tendon Degeneration: A Molecular Perspective

Tendinopathy is a debilitating condition marked by degenerative changes in the tendons. Its complex pathophysiology involves intrinsic, extrinsic, and physiological factors. While its intrinsic and extrinsic factors have been extensively studied, the role of physiological factors, such as hypoxia and oxidative stress, remains largely unexplored. This review article delves into the contribution of hypoxia-associated genes and oxidative-stress-related factors to tendon degeneration, offering insights into potential therapeutic strategies. The unique aspect of this study lies in its pathway-based evidence, which sheds light on how these factors can be targeted to enhance overall tendon health.

Ginsenoside Rc, an Active Component of Panax ginseng, Alleviates Oxidative Stress-Induced Muscle Atrophy via Improvement of Mitochondrial Biogenesis

Loss of skeletal muscle mass and function has detrimental effects on quality of life, morbidity, and mortality, and is particularly relevant in aging societies. The enhancement of mitochondrial function has shown promise in promoting muscle differentiation and function. Ginsenoside Rc (gRc), a major component of ginseng, has various pharmacological activities; however, its effect on muscle loss remains poorly explored. In this study, we examined the effects of gRc on the hydrogen peroxide (H2O2)-induced reduction of cell viability in C2C12 myoblasts and myotubes and H2O2-induced myotube degradation. In addition, we investigated the effects of gRc on the production of intracellular reactive oxygen species (ROS) and mitochondrial superoxide, ATP generation, and peroxisome proliferator-activated receptor-gamma co-activator 1α (PGC-1α) activity in myoblasts and myotubes under H2O2 treatment. Furthermore, to elucidate the mechanism of action of gRc, we conducted a transcriptome analysis of myotubes treated with or without gRc under H2O2 treatment. gRc effectively suppressed H2O2-induced cytotoxicity, intracellular ROS, and mitochondrial superoxide production, restored PGC-1α promoter activity, and increased ATP synthesis. Moreover, gRc significantly affected the expression levels of genes involved in maintaining mitochondrial mass and biogenesis, while downregulating genes associated with muscle degradation in C2C12 myotubes under oxidative stress. We provide compelling evidence supporting the potential of gRc as a promising treatment for muscle loss and weakness. Further investigations of the pharmacological effects of gRc under various pathological conditions of muscle loss will contribute to the clinical development of gRc as a therapeutic intervention.

Mitochondrial Oxidative Stress and Mitophagy Activation Contribute to TNF-Dependent Impairment of Myogenesis

Many muscular pathologies are associated with oxidative stress and elevated levels of the tumor necrosis factor (TNF) that cause muscle protein catabolism and impair myogenesis. Myogenesis defects caused by TNF are mediated in part by reactive oxygen species (ROS), including those produced by mitochondria (mitoROS), but the mechanism of their pathological action is not fully understood. We hypothesized that mitoROS act by triggering and enhancing mitophagy, an important tool for remodelling the mitochondrial reticulum during myogenesis. We used three recently developed probes—MitoTracker Orange CM-H2TMRos, mito-QC, and MitoCLox—to study myogenesis in human myoblasts. Induction of myogenesis resulted in a significant increase in mitoROS generation and phospholipid peroxidation in the inner mitochondrial membrane, as well as mitophagy enhancement. Treatment of myoblasts with TNF 24 h before induction of myogenesis resulted in a significant decrease in the myoblast fusion index and myosin heavy chain (MYH2) synthesis. TNF increased the levels of mitoROS, phospholipid peroxidation in the inner mitochondrial membrane and mitophagy at an early stage of differentiation. Trolox and SkQ1 antioxidants partially restored TNF-impaired myogenesis. The general autophagy inducers rapamycin and AICAR, which also stimulate mitophagy, completely blocked myogenesis. The autophagy suppression by the ULK1 inhibitor SBI-0206965 partially restored myogenesis impaired by TNF. Thus, suppression of myogenesis by TNF is associated with a mitoROS-dependent increase in general autophagy and mitophagy.