Search Results (156)

Skeletal muscle development is a critical economic trait in livestock, governed by myogenic satellite cell regulation. Integrins mediate mechanical anchorage to the ECM and enable ECM–intracellular signaling. CIB2, as an EF-hand-domain protein involved in mechanotransduction, shows significant developmental regulation in goat muscle. Although the role of CIB2 in skeletal muscle growth is poorly characterized, we observed pronounced developmental upregulation of IB2 in postnatal goat muscle. CIB2 expression increased >20-fold by postnatal day 90 (P90) compared to P1, sustaining elevation through P180 (p < 0.05). Functional investigations indicated that siRNA-mediated knockdown of CIB2 could inhibit myoblast proliferation by inducing S-phase arrest (p < 0.05) and downregulating the expression of CDK4/Cyclin D/E. Simultaneously, CIB2 interference treatment was found to decrease the proliferative activity of goat myogenic satellite cells, yet it significantly promoted differentiation by upregulating the expression of MyoD/MyoG/MyHC (p < 0.01). Mechanistically, CTCF was identified as a transcriptional repressor binding to an intragenic region of the CIB2 gene locus (ChIP enrichment: 2.3-fold, p < 0.05). Knockdown of CTCF induced upregulation of CIB2 (p < 0.05). RNA-seq analysis established CIB2 as a calcium signaling hub: its interference activated IL-17/TNF and complement cascades, while overexpression suppressed focal adhesion/ECM–receptor interactions and enriched neuroendocrine pathways. Collectively, this study identifies the CTCF-CIB2–integrin α7β1–PI3K/AKT axis as a novel molecular mechanism that regulates the balance of myogenic fate in goats. These findings offer promising targets for genomic selection and precision breeding strategies aimed at enhancing muscle productivity in ruminants. Full article

Prenatal and postnatal skeletal muscle development in ruminants is coordinated by interactions between genetic, nutritional, epigenetic, and endocrine factors. This review focuses on the influence of maternal nutrition during gestation on fetal myogenesis, satellite cell dynamics, and myogenic regulatory factors expression, including MYF5, MYOD1, and MYOG. Studies in sheep and cattle indicate that nutrient restriction or overnutrition alters muscle fiber number, the cross-sectional area, and the transcriptional regulation of myogenic genes in offspring. Postnatally, muscle hypertrophy is primarily mediated by satellite cells, which are activated via PAX7, MYOD, and MYF5, and regulated through mechanisms such as CARM1-induced chromatin remodeling and miR-31-mediated mRNA expression. Hormonal signaling via the GH–IGF1 axis and thyroid hormones further modulate satellite cell proliferation and protein accretion. Genetic variants, such as myostatin mutations in Texel sheep and Belgian Blue cattle, enhance muscle mass but may compromise reproductive efficiency. Nutritional interventions, including the plane of nutrition, supplementation strategies, and environmental stressors such as heat and stocking density, significantly influence muscle fiber composition and carcass traits. This review provides a comprehensive overview of skeletal muscle programming in ruminants, tracing the developmental trajectory from progenitor cell differentiation to postnatal growth and maturation. These insights underscore the need for integrated approaches combining maternal diet optimization, molecular breeding, and precision livestock management to enhance muscle growth, meat quality, and production sustainability in ruminant systems. Full article

Disused muscle atrophy (DMA) is characterized by skeletal muscle loss and functional decline due to prolonged inactivity. Though evidence remains limited, recent studies suggest that ferroptosis, an iron-dependent, lipid peroxidation-driven form of cell death, may contribute to DMA. Taurine, a natural amino acid enriched in energy drinks, can improve the proliferation and myogenic differentiation potential of myoblasts. This study aimed to investigate whether taurine supplementation could protect against DMA and explore its potential role in modulating ferroptosis. Using a hindlimb suspension-induced DMA model in male C57BL/6J mice (6–8 weeks old), we assessed muscle mass, function, ferroptosis-related markers, histopathological changes, and metabolic alterations. The results showed that taurine supplementation improved muscle strength and morphology while attenuating markers of ferroptosis, including iron accumulation, lipid peroxidation, and glutathione and related protein (NRF2, GPX4, and xCT) depletion. Metabolomic analysis suggested that taurine modulates disorders in glutathione and lipid metabolism, potentially associated with the regulation of the xCT-GSH-GPX4 and AMPK-ACC-ACSL4 pathways. While these findings support a protective role for taurine and a possible link between ferroptosis and DMA, further functional studies are needed to confirm causality and assess the compound’s translational potential. This study provides initial in vivo evidence implicating ferroptosis in DMA and highlights taurine as a promising candidate for future therapeutic exploration. Full article

Skeletal muscle is the largest heterogeneous organ in the body, and multiple factors in intrinsic genetic and epigenetic regulation influence its growth. The N⁶-methyladenosine ed(m⁶A) modification is a conserved and most prevalent RNA modification, whose function is dependent on m⁶A writers, erasers, and m⁶A readers, such as the YTH protein family. YTHDC1 is the only member of the YTH protein family member that exists in the cell nucleus, which plays an important role in mRNA alternative polyadenylation and alternative splicing processes. However, the function of YTHDC1 in regulating myoblast proliferation, differentiation, and in vivo skeletal muscle development remains unclear. Therefore, in this study, we studied the function of YTHDC1 in C2C12 cell line and mouse. Our results showed that YTHDC1 significantly promoted myogenic differentiation while inhibiting myoblast proliferation in C2C12 cells, and the results of our in vivo experiment showed that interfering with YTHDC1 led to a significant enhancement of muscle growth in mice. Furthermore, the transcriptome sequencing analysis revealed that YTHDC1 might modulate skeletal muscle development by regulating alternative splicing of genes, including Akap13, Smarca2, Tnnt3, and Neb. Our study shed light on understanding the function and molecular mechanisms of YTHDC1 in regulating skeletal muscle development, highlighting the critical contribution of m⁶A-mediated RNA splicing in muscle growth. These results indicated that YTHDC1 could be a potential breeding target gene to enhance meat quality in livestock. Full article

Cyclic mechanical stretch has been shown to inhibit myoblast differentiation while promoting proliferation. However, the underlying molecular mechanisms are not well understood. Here, we report that mechanical stretch inhibits the differentiation of mouse primary myoblasts by promoting the cell cycle program and by inhibiting the expression of the myogenic regulator MyoD. Stretch alters the miRNA expression profile as evidenced by miRNA microarray analysis. We identified miR-200c as one of the highly downregulated mechanosensitive miRNAs (mechanomiRs) whose expression level was increased during differentiation. This suggests that mechanomiRs-200c is a myogenic miRNA. Overexpression of mechanomiR-200c revoked the effect of stretch on myoblast differentiation, and the introduction of the mechanomiR-200c antagomir restored the stretch effect. This suggests that stretch blocks differentiation, in part, through mechanomiR-200c. The gene encoding the transcription factor FoxO3 is a known direct target of mechanomiR-200c. Interestingly, MyoD binds to the mechanomiR-200c promoter in differentiating myoblasts, whereas stretch appears to reverse such binding. Our data further demonstrate that the levels of mechanomiR-200c are robustly elevated during the early stage of the muscle repair process in young mice, but not in the injured muscle of aged mice. Overall, we identified a novel pathway, MyoD/mechanomiR-200c/FoxO3a, and the potential mechanism by which stretch inhibits myoblast differentiation. Full article

MSTN has been used as a candidate gene in the genetics, breeding, and improvement of animal breeds. However, the possible mechanism by which the MSTN gene regulates muscle development through PSMA6 is not well understood. Previous methylome and transcriptome sequencing analyses of gluteal muscle tissues from MSTN+/−Luxi cattle and wild-type Luxi cattle identified that the PSMA6 gene exhibited a negative correlation between methylation levels and transcriptional activity. To investigate whether MSTN expression regulates PSMA6 gene expression, we examined the effects of MSTN on DNA methyltransferases (DNMT1, DNMT2, DNMT3A, and DNMT3B) and DNA demethylases (TET1, TET2, and TET3). Additionally, chromatin immunoprecipitation (ChIP) assays were performed to detect the binding interaction between PSMA6 and TET2. In this paper, we first established an MSTN knockdown cellular model to preliminarily validate its regulatory effect on PSMA6 expression. Subsequently, the developmental impact of PSMA6 on bovine skeletal muscle satellite cells was further investigated through both knockdown and overexpression of the PSMA6 gene. Furthermore, we examined changes in the expression of key components of the AKT/mTOR signaling pathway to elucidate the mechanisms underlying the PSMA6-mediated regulation of satellite cell development. The results demonstrate that myostatin (MSTN) inhibition significantly decreased proteasome 20S subunit alpha-6 (PSMA6) gene expression, while increasing demethylase expression, particularly ten-eleven translocation-2 (TET2), which exhibited the most pronounced changes. During the cell proliferation stage, the markers Paired Box 7 (PAX7) and Ki-67 exhibited no significant changes, whereas the PSMA6 gene was either overexpressed or disrupted. Conversely, PSMA6 overexpression altered the myogenic differentiation markers, causing the differential regulation of myosin heavy chain (MyHC) and myogenin (MyoG) expression, with MyHC upregulation and concurrent MyoG downregulation. PSMA6 gene overexpression led to the downregulation of AKT1 and Rac1, as well as the activation of the AKT/mTOR pathway, including key factors such as mTOR, p-mTOR, RPS6, p-RPS6, and RhoA. PSMA6 interference resulted in the downregulation of p-mTOR and the upregulation of p-RPS6. Gene expression profiling in our study revealed that the myostatin (MSTN) knockout model significantly reduced the transcriptional levels of the proteasome α6 subunit (PSMA6) (p < 0.05), with the regulatory intensity showing a significant negative correlation with MSTN expression. This molecular evidence substantiates a negative regulatory axis between MSTN and PSMA6. Functional experiments demonstrated that PSMA6 overexpression specifically enhanced myotube formation rates in bovine skeletal muscle satellite cells, whereas siRNA-mediated PSMA6 knockdown exhibited no significant effects on cellular proliferation, indicating the functional specificity of this gene in myogenic differentiation. Mechanistic investigations further revealed that PSMA6 activates the canonical AKT/mTOR signaling transduction cascade through the phosphorylation of AKT and its downstream effector mTOR, thereby mediating the expression of myogenic regulatory factors MyoD and myogenin. Collectively, these findings demonstrate that MSTN deficiency alleviates the transcriptional repression of PSMA6, remodels skeletal muscle differentiation-associated signaling networks, and ultimately drives the directional differentiation of satellite cells toward myofiber specification. Full article

Myogenesis is a complex biological process regulated by multiple factors. This study systematically revealed the dynamic changes of gene expression and its regulatory network in C2C12 myoblasts during proliferation and differentiation stages by integrating transcriptome and miRNA-omics data. The analysis results showed that in the early stage of proliferation, gene expression showed significant fluctuations, and key cell cycle and DNA replication-related genes were closely associated with specific miRNAs (miR-486a-5p, miR-486b-5p, and miR-351-5p), suggesting that these miRNAs play an important role in regulating cell proliferation. In the differentiation stage, the activation of key myogenic transcription factors and signaling pathways, such as MAPK and PI3K-Akt, synergizes with miRNA regulation to promote the myogenic program. In addition, we found that genes such as IGF1 and Dio2 were continuously upregulated during differentiation, and IGF1 might be regulated by multiple miRNAs during this process. This study provides key molecular insights for a deeper understanding of muscle development and regeneration. Full article

Stimulating skeletal muscle satellite cells (SMSCs) with amino acids improves their proliferation and differentiation, enhancing skeletal muscle mass, thereby increasing lean meat rate. This study explored lysine (Lys)’s effects on SMSCs and their protein profiles in Sunit sheep. SMSCs were successfully isolated, assessing their survival and proliferation after Lys stimulation at varying concentrations using the CCK-8 assay. Western blotting revealed Lys-induced changes in myogenic differentiation protein expression, while immunocytochemistry detected α-Actinin and Myostatin within the SMSCs. TMT proteomics identified differentially expressed proteins, which underwent functional and interaction analyses, with RT-qPCR validating the corresponding gene expression. This study revealed that 4 mmol/L of Lys significantly boosted SMSC proliferation. A 24 h stimulation with this concentration reduced Myostatin expression, and increased MYOD1 and α-Actinin levels in the SMSCs. A proteomic analysis identified 577 differentially expressed proteins, primarily associated with lipoblast differentiation and muscle development, as highlighted by the GO enrichment analysis. A pathway analysis further demonstrated these proteins’ involvement in the autophagy–lysosome and NOD-like receptor signaling pathways. Lys enhances SMSC proliferation, differentiation, and adipogenesis in Sunit sheep, exhibiting antioxidant properties and supporting muscle stability and amino acid metabolism. It may also have anti-inflammatory, anti-pyroptotic, and proteolysis-inhibitory effects, offering insights into muscle growth mechanisms through amino acid supplementation in ruminants. Full article

Extracellular vesicles (EVs) are membrane-bound structures released by cells carrying diverse biomolecules involved in intercellular communication. Small EVs are abundant in body fluids, playing a key role in cell signaling. Their natural occurrence and therapeutic potential, especially in the context of muscular disorders, make them a significant area of research. Sarcopenia, characterized by progressive muscle fiber loss, represents a pathological state in which EVs could offer therapeutic benefits, reducing morbidity and mortality. Recent studies have proposed an interplay between adipose tissue (AT) and skeletal muscle regarding sarcopenia pathology. AT dysregulation, as seen in obesity, contributes to skeletal muscle loss in a multifactorial way. While AT-derived stem cell (ATDSC) small EVs have been implicated in musculoskeletal homeostasis, their precise action in muscle regeneration remains incompletely understood. In this context, ATDSC-derived small EVs can stimulate skeletal muscle regeneration through improved proliferation and migration of muscle cells, enhancement of muscular perfusion, improvement of tendon and nerve regeneration, stimulation of angiogenesis, and promotion of myogenic differentiation. However, they can also increase skeletal muscle loss. Notably, this is the first comprehensive review to systematically examine the role of ATDSC-derived small EVs in sarcopenia. Full article

The DHRS3 gene, a member of the short-chain dehydrogenase/reductase (SDR) family, is involved in critical metabolic processes in animals. This study investigated the expression patterns of DHRS3 across various tissues of developmental stages in pigs and preliminarily evaluated its effects on myoblast proliferation, apoptosis, and differentiation. RT-qPCR (real-time quantitative PCR) was employed to analyze DHRS3 expression in the heart, liver, spleen, lungs, kidneys, longissimus dorsi, foreleg, and hind leg of pigs at 3 days, 6 months, and 12 months of age. Cell proliferation was analyzed using EdU (5-ethynyl-2′-deoxyuridine) assays, RT-qPCR, and flow cytometry, while the expression changes of proliferation-, apoptosis-, and differentiation-related genes were assessed via RT-qPCR. The results indicated that DHRS3 was expressed in all eight tissues at all three developmental stages. At 3 days, DHRS3 expression was the highest in the kidneys; at 6 months, it peaked in the liver; and at 12 months, it was again the highest in the kidneys. Across all stages, the liver and kidneys exhibited the highest DHRS3 expression levels. Functional studies revealed that DHRS3 overexpression suppressed myoblast proliferation and differentiation while promoting apoptosis. In contrast, DHRS3 inhibition enhanced myoblast proliferation and differentiation and reduced apoptosis. These findings underscore the regulatory role of DHRS3 in myogenesis and provide insights into its metabolic and developmental functions in pigs. Full article

Low birth weight (LBW) in various species leads to a pronounced skeletal muscle phenotype and can serve as a model to study muscle formation and draw conclusions for normal and pathological development. We aimed to elucidate in detail how the differentiation of muscular stem cells and their progeny are disturbed in piglets born with LBW. We isolated primary muscle cells from LBW piglets and their normal siblings with two different approaches: (1) single cells from two functionally divergent subpopulations (previously named “fast” and “slow”) and (2) cells derived from isolated, intact myofibers. Subsequently, we analyzed their proliferative and differentiative capacity by determining proliferation rate, migration behavior, myotube formation, and myogenic gene and protein expression. LBW led to a decreased proliferation rate and migration potential in cells from the subpopulation fast group. Cells from LBW piglets were generally able to differentiate, but they formed smaller myotubes with less incorporated nuclei, leading to a diminished fusion rate. Myogenic gene expression was also significantly altered due to pig birth weight. Overall, early postnatal muscle development in LBW was disturbed at several crucial steps involving the establishment of a reserve stem cell pool, movement of cells towards existing myofibers, and the ability to form nascent myofibers. Full article

Sustainable food resources, including cell-cultured meat and edible insect proteins, are emerging as key solutions to meet future protein demands. This study evaluated the effects of black soldier fly larvae hydrolysate (BLH) on primary cells isolated from broiler leg and breast muscle tissues, as well as abdominal fat tissues. Primary cells isolated from each tissue were characterized for their myogenic and adipogenic (stromal vascular fraction, SVF) properties. Cells were cultured in a basal medium with five percent FBS supplemented with BLH at concentrations ranging from 25 to 300 µg/mL. Leg and breast muscle cells showed significantly enhanced proliferation, as indicated by MTS assay results and cell counts, in the BLH100 group compared to the FBS5 and control groups (p < 0.05). Furthermore, the expression of myogenic markers, including PAX7, NCAM1, MYF5, and MYOD1, was upregulated in leg muscle cells treated with BLH (p < 0.05). For SVFs, BLH50 promoted cell proliferation; however, differentiation decreased as BLH concentration increased. These findings suggest that BLH can enhance the proliferation of primary broiler cells, highlighting its potential applicability in the edible insect and cultured meat industries. Full article

Mesenchymal stem cells (MSCs) have gained recognition as a highly versatile and promising cell source for repopulating bioengineered scaffolds due to their inherent capacity to differentiate into multiple cell types. However, MSC implantation techniques have often yielded inconsistent clinical results, underscoring the need for advanced approaches to enhance their therapeutic efficacy. Recent developments in three-dimensional (3D) bioengineered scaffolds have provided a significant breakthrough by closely mimicking the in vivo environment, addressing the limitations of traditional two-dimensional (2D) cell cultures. Among these, nanofibrous scaffolds have proven particularly effective, offering an optimal 3D framework, growth-permissive substrates, and the delivery of trophic factors crucial for MSC survival and regeneration. Furthermore, the selection of appropriate biomaterials can amplify the paracrine effects of MSCs, promoting both proliferation and targeted differentiation. The synergistic combination of MSCs with nanofibrous scaffolds has demonstrated remarkable potential in achieving repair, regeneration, and tissue-specific differentiation with enhanced safety and efficacy, paving the way for routine clinical applications. In this review, we examine the most recent studies (2013–2023) that explore the combined use of MSCs and nanofibrous scaffolds for differentiation into cardiogenic, epithelial, myogenic, tendon, and vascular cell lineages. Using PubMed, we identified and analyzed 275 relevant articles based on the search terms “Nanofibers”, “Electrospinning”, “Mesenchymal stem cells”, and “Differentiation”. This review highlights the critical advancements in the use of nanofibrous scaffolds as a platform for MSC differentiation and tissue regeneration. By summarizing key findings from the last decade, it provides valuable insights for researchers and clinicians aiming to optimize scaffold design, MSC integration, and translational applications. These insights could significantly influence future research directions and the development of more effective regenerative therapies. Full article

An actin-binding protein, known as Calponin 3 (CNN3), modulates the remodeling of the actin cytoskeleton, a fundamental process for the maintenance of skeletal muscle homeostasis. Although the roles of CNN3 in actin remodeling have been established, its biological significance in myoblast differentiation remains largely unknown. This study investigated the functional significance of CNN3 in myogenic differentiation, along with its effects on actin remodeling and mechanosensitive signaling in C2C12 myoblasts. CNN3 knockdown led to a marked increase in filamentous actin, which promoted the nuclear localization of Yes-associated protein 1 (YAP1), a mechanosensitive transcriptional coactivator required for response to the mechanical cues that drive cell proliferation. Subsequently, CNN3 depletion enhanced myoblast proliferation by upregulating the expression of the YAP1 target genes related to cell cycle progression, such as cyclin B1, cyclin D1, and PCNA. According to a flow cytometry analysis, CNN3-deficient cells displayed higher S and G2/M phase fractions, which concurred with elevated proliferation rates. Furthermore, CNN3 knockdown impaired myogenic differentiation, as evidenced by reduced levels of MyoD, MyoG, and MyHC, key markers of myogenic commitment and maturation, and immunocytochemistry showed that myotube formation was diminished in CNN3-suppressed cells, which was supported by lower differentiation and fusion indices. These findings reveal that CNN3 is essential for myogenic differentiation, playing a key role in regulating actin remodeling and cellular localization of YAP1 to orchestrate the proliferation and differentiation in myogenic progenitor cells. This study highlights CNN3 as a critical regulator of skeletal myogenesis and suggests its therapeutic potential as a target for muscle atrophy and related disorders. Full article

This study investigated the effects of long-term serum starvation on autophagy, metabolism, and differentiation of porcine skeletal muscle satellite cells (SMSCs) and elucidated the role of autophagy in skeletal muscle development. Our findings provide a theoretical basis for improving meat production in domestic pigs. The SMSCs isolated and preserved in our laboratory were revived and divided into six groups based on the culture medium serum concentration to simulate varying levels of serum starvation: 20% serum (control group), 15% serum (mild serum starvation group), 5% serum (severe serum starvation group), and their autophagy inhibition groups supplemented with 3-methyladenine. After 96 h of culture, the apoptosis rate, mitochondrial membrane potential, reactive oxygen species, and ATP were measured to evaluate the effects of serum starvation on the SMSCs’ metabolism. Additionally, the levels of autophagy-related proteins, autophagosomes, and autolysosomes were measured to investigate the impact of long-term serum starvation on autophagy. The expression of proteins associated with myogenic and adipogenic differentiation (MHC, MyoD1, peroxisome proliferator-activated receptor γ, and lipoprotein lipase) as well as lipid content were also determined to investigate the effects of long-term serum starvation on SMSC differentiation. The results showed that long-term serum starvation induced autophagy through the AMPK/mTOR signaling pathway, accelerated cell metabolism and apoptosis, exacerbated reactive oxygen species accumulation, and inhibited myogenic and adipogenic differentiation of SMSCs. Moreover, these effects were positively correlated with the level of serum starvation. In addition, serum starvation-induced autophagy moderately promoted the myogenic and adipogenic differentiation of SMSCs; however, these effects were insufficient to counteract the inhibition of cell differentiation by long-term serum starvation. This study provides insight into leveraging serum starvation as a stressor to regulate muscle growth and metabolism in domestic pigs. Full article