Effect of succinic acid on the processes of myogenesis was investigated in the study with the cells of C2C12 line. In the concentration range 10-1000 µM, succinic acid stimulated the process of myogenic differentiation, increasing the levels of myogenesis factors MyoD (at all stages of myogenesis) and myogenin (at the stage of terminal differentiation). Presence of the succinate receptors SUCNR1 was revealed in the C2C12 cells using Western blotting, level of which decreased during myogenesis. When succinic acid was added to the cells, the level of intracellular succinate did not change significantly and decreased during myogenic differentiation. Using a specific Gai protein inhibitor, pertussis toxin, it was found that stimulation of myogenesis in the C2C12 cells under the action of succinic acid is realized through SUCNR1-Gai interaction.

Trichinosis is a common parasitic disease that affects the striated skeletal muscles, causing apoptotic and degenerative changes associated with myogenin expression in the affected myocytes. Hence, this study aimed to assess the ameliorative effects of stem cells and atorvastatin added to ivermectin on the infected myocytes during the muscular phase of murine trichinosis. 120 laboratory Swiss albino male mice were divided into 10 groups, and each group was subdivided into intestinal and muscular phases (each n = 6); uninfected control; untreated infected control; infected received ivermectin monotherapy; infected received atorvastatin monotherapy; infected received stem cells monotherapy; infected received ivermectin and atorvastatin dual therapy; infected received ivermectin and stem cells dual therapy; infected received atorvastatin and stem cells dual therapy; infected received ivermectin 0.2, atorvastatin 40, and stem cells triple therapy; and infected received ivermectin 0.1, atorvastatin 20, and stem cells triple therapy. Intestinal phase mice were sacrificed on the 5th day post-infection, while those of the muscular phase were sacrificed on the 35th day post-infection. Parasitological, histopathological, ultrastructural, histochemical, biochemical, and myogenin gene expression assessments were performed. The results revealed that mice that received ivermectin, atorvastatin, and stem cell triple therapies showed the maximum reduction in the adult worm and larvae burden, marked improvement in the underlying muscular degenerative changes (as was noticed by histopathological, ultrastructural, and histochemical Feulgen stain assessment), lower biochemical levels of serum NK-κB and tissue NO, and lower myogenin expression. Accordingly, the combination of stem cells, atorvastatin, and ivermectin affords a potential synergistic activity against trichinosis with considerable healing of the underlying degenerative sequel.

Metformin is an important antidiabetic drug that has the potential to reduce skeletal muscle atrophy and promote the differentiation of muscle cells. However, the exact molecular mechanism underlying these functions remains unclear. Previous studies revealed that the transcription factor zinc finger E-box-binding homeobox 1 (ZEB1), which participates in tumor progression, inhibits muscle atrophy. Therefore, we hypothesized that the protective effect of metformin might be related to ZEB1. We investigated the positive effect of metformin on IL-1β-induced skeletal muscle atrophy by regulating ZEB1 in vitro and in vivo. Compared with the normal cell differentiation group, the metformin-treated group presented increased myotube diameters and reduced expression levels of atrophy-marker proteins. Moreover, muscle cell differentiation was hindered, when we artificially interfered with ZEB1 expression in mouse skeletal myoblast (C2C12) cells via ZEB1-specific small interfering RNA (si-ZEB1). In response to inflammatory stimulation, metformin treatment increased the expression levels of ZEB1 and three differentiation proteins, MHC, MyoD, and myogenin, whereas si-ZEB1 partially counteracted these effects. Moreover, marked atrophy was induced in a mouse model via the administration of lipopolysaccharide (LPS) to the skeletal muscles of the lower limbs. Over a 4-week period of intragastric administration, metformin treatment ameliorated muscle atrophy and increased the expression levels of ZEB1. Metformin treatment partially alleviated muscle atrophy and stimulated differentiation. Overall, our findings may provide a better understanding of the mechanism underlying the effects of metformin treatment on skeletal muscle atrophy and suggest the potential of metformin as a therapeutic drug.

OBJECTIVE: We investigated the effects of mouse-derived DFAT on the myogenic differentiation of a mouse-derived myoblast cell line (C2C12) and examined the therapeutic effects of rat-derived DFAT on anal sphincter injury using a rat model.
METHODS: C2C12 cells were cultured using DMEM and DFAT-conditioned medium (DFAT-CM), evaluating MyoD and Myogenin gene expression via RT-PCR. DFAT was locally administered to model rats with anorectal sphincter dysfunction 3 days post-CTX injection. Therapeutic effects were assessed through functional assessment, including anal pressure measurement using solid-state manometry pre/post-CTX, and on days 1, 3, 7, 10, 14, 17, and 21 post-DFAT administration. Histological evaluation involved anal canal excision on days 1, 3, 7, 14, and 21 after CTX administration, followed by hematoxylin-eosin staining.
RESULTS: C2C12 cells cultured with DFAT-CM exhibited increased MyoD and Myogenin gene expression compared to control. Anal pressure measurements revealed early recovery of resting pressure in the DFAT-treated group. Histologically, DFAT-treated rats demonstrated an increase in mature muscle cells within newly formed muscle fibers on days 14 and 21 after CTX administration, indicating enhanced muscle tissue repair.
CONCLUSIONS: DFAT demonstrated the potential to enhance histological and functional muscle tissue repair. These findings propose DFAT as a novel therapeutic approach for anorectal sphincter dysfunction treatment.

Sestrin2 (Sesn2) has been previously confirmed to be a stress-response molecule. However, the influence of Sesn2 on myogenic differentiation remains elusive. This study was conducted to analyze the role of Sesn2 in the myogenic differentiation of C2C12 myoblasts and related aspects in mdx mice, an animal model of Duchenne muscular dystrophy (DMD). Our results showed that knockdown of Sesn2 reduced the myogenic differentiation capacity of C2C12 myoblasts. Predictive analysis from two databases suggested that miR-182-5p is a potential regulator of Sesn2. Further experimental validation revealed that overexpression of miR-182-5p decreased both the protein and mRNA levels of Sesn2 and inhibited myogenesis of C2C12 myoblasts. These findings suggest that miR-182-5p negatively regulates myogenesis by repressing Sesn2 expression. Extending to an in vivo model of DMD, knockdown of Sesn2 led to decreased Myogenin (Myog) expression and increased Pax7 expression, while its overexpression upregulated Myog levels and enhanced the proportion of slow-switch myofibers. These findings indicate the crucial role of Sesn2 in promoting myogenic differentiation and skeletal muscle regeneration, providing potential therapeutic targets for muscular dystrophy.

Cancer cachexia is a prevalent and often fatal wasting condition that cannot be fully reversed with nutritional interventions. Muscle atrophy is a central component of the syndrome, but the mechanisms whereby cancer leads to skeletal muscle atrophy are not well understood. We performed single-nucleus multi-omics on skeletal muscles from a mouse model of cancer cachexia and profiled the molecular changes in cachexic muscle. Our results revealed the activation of a denervation-dependent gene program that upregulates the transcription factor myogenin. Further studies showed that a myogenin-myostatin pathway promotes muscle atrophy in response to cancer cachexia. Short hairpin RNA inhibition of myogenin or inhibition of myostatin through overexpression of its endogenous inhibitor follistatin prevented cancer cachexia-induced muscle atrophy in mice. Our findings uncover a molecular basis of muscle atrophy associated with cancer cachexia and highlight potential therapeutic targets for this disorder.

The aims of current investigation were to study the growth performance, carcass traits, meat quality and expression profile of Myostatin (MSTN), Insulin-like growth factor-1 (IGF-I), Myogenin (MyoG) and Myogenic regulatory factor 4 (MRF4) genes in three commercial broiler strains including Ross (Ross 308), Cobb (Cobb 500), and Arian in 2023. A total number of 240 one-day-old chicks were reared under an equalized standard management condition for 6 weeks. Performance, organ weights, meat quality and the expression level of the myogenic genes in the pectoral muscle were investigated. The lowest body weight (BW), feed intake, weight gain and highest feed conversion ratio (FCR) was observed for Arian at the end of the study. The meat quality was similar between strains. The IGF-I expression level was significantly higher on 42 days of age in Cobb compared to Ross and Arian. The MRF4 expression level was significantly higher on 28 days of age in Cobb compared to Ross. The MyoG expression level was significantly lower in Arian compared to Cobb on 42 days of age. Furthermore, the MSTN expression level was significantly lower in Cobb compared to Ross and Arian on 42 days of age. The remarkable differences in gene expression levels at the end of the rearing period was supported by higher growth performance and BW of Cobb compared to Ross and Arian strains. In conclusion, the findings of current study could conveniently help assess the performance of these broiler strains under similar rearing condition.

Interactions between tissues and cell types, mediated by cytokines or direct cell-cell exchanges, regulate growth. To determine whether mature adipocytes influence the in vitro growth of trout mononucleated muscle cells, we developed an indirect coculture system, and showed that adipocytes (5 × 106 cells/well) derived from perivisceral adipose tissue increased the proliferation (BrdU-positive cells) of the mononucleated muscle cells (26% vs. 39%; p < 0.001) while inhibiting myogenic differentiation (myosin+) (25% vs. 15%; p < 0.001). Similar effects were obtained with subcutaneous adipose tissue-derived adipocytes, although requiring more adipocytes (3 × 107 cells/well vs. 5 × 106 cells/well). Conditioned media recapitulated these effects, stimulating proliferation (31% vs. 39%; p < 0.001) and inhibiting myogenic differentiation (32 vs. 23%; p < 0.001). Adipocytes began to reduce differentiation after 24 h, whereas proliferation stimulation was observed after 48 h. While adipocytes did not change pax7+ and myoD1/2+ percentages, they reduced myogenin+ cells showing inhibition from early differentiation stage. Finally, adipocytes increased BrdU+ cells in the Pdgfrα+ population but not in the myoD+ one. Collectively, our results demonstrate that trout adipocytes promote fibro-adipocyte precursor proliferation while inhibiting myogenic cells differentiation in vitro, suggesting the key role of adipose tissue in regulating fish muscle growth.

UNASSIGNED: Alveolar rhabdomyosarcoma (ARMS) shows a predilection for the peripheral extremities and is very rarely identified as a primary in the brain. Here, we report a case of ARMS with multiple lesions exclusively within the central nervous system (CNS).
UNASSIGNED: A 20-year-old man presented to our hospital with a gradually increasing headache and disturbance of consciousness. Neuroimaging showed hydrocephalus and multiple tumor lesions, including in the brainstem and cerebellum, with uniform gadolinium enhancement on T1-weighted magnetic resonance imaging, as well as spinal cord seeding. Cerebrospinal fluid (CSF) analysis showed a slightly elevated cell count (6/μL; normal, <5/μL) and highly elevated protein (153 mg/dL). In addition, atypical cells were cytologically identified in the CSF. No other laboratory findings were abnormal. Emergency ventricular drainage was performed to control cerebral pressure, followed by a biopsy to confirm the diagnosis. Histological examination revealed a fascicular arrangement of oval cells with eosinophilic cytoplasm and tumor cells with pleomorphic nuclei and prominent nucleoli. Immunohistochemical studies showed negative results for glial fibrillary acidic protein and positive results for desmin and myogenin. In addition, molecular analysis revealed that this tumor had the H3F3A p.Lys28Met mutation and no paired box (PAX)3-forkhead box O1 (FOXO1) or PAX7-FOXO1 fusion genes. ARMS was, therefore, diagnosed. Chemotherapy and radiotherapy were subsequently initiated, but tumor growth could not be controlled, and the patient died 6 months after surgery.
UNASSIGNED: This report describes an extremely rare case of ARMS arising exclusively within the CNS.

BACKGROUND: Photobiomodulation has exhibited promise in mitigating the local effects induced by Bothrops snakebite envenoming; however, the mechanisms underlying this protection are not yet fully understood. Herein, the effectiveness of photobiomodulation effects on regenerative response of C2C12 myoblast cells following exposure to Bothrops jararacussu venom (BjsuV), as well as the mechanisms involved was investigated.
RESULTS: C2C12 myoblast cells were exposed to BjsuV (12.5 μg/mL) and irradiated once for 10 seconds with laser light of 660 nm (14.08 mW; 0.04 cm2; 352 mW/cm2) or 780 nm (17.6 mW; 0.04 cm2; 440 mW/ cm2) to provide energy densities of 3.52 and 4.4 J/cm2, and total energies of 0.1408 and 0.176 J, respectively. Cell migration was assessed through a wound-healing assay. The expression of MAPK p38-α, NF-Кβ, Myf5, Pax-7, MyoD, and myogenin proteins were assessed by western blotting analysis. In addition, interleukin IL1-β, IL-6, TNF-alfa and IL-10 levels were measured in the supernatant by ELISA. The PBM applied to C2C12 cells exposed to BjsuV promoted cell migration, increase the expression of myogenic factors (Pax7, MyF5, MyoD and myogenin), reduced the levels of proinflammatory cytokines, IL1-β, IL-6, TNF-alfa, and increased the levels of anti-inflammatory cytokine IL-10. In addition, PBM downregulates the expression of NF-kB, and had no effect on p38 MAKP.
CONCLUSIONS: These data demonstrated that protection of the muscle cell by PBM seems to be related to the increase of myogenic factors as well as the modulation of inflammatory mediators. PBM therapy may offer a new therapeutic strategy to address the local effects of snakebite envenoming by promoting muscle regeneration and reducing the inflammatory process.