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PLoS Genetics Jun 2023Four SIX homeoproteins display a combinatorial expression throughout embryonic developmental myogenesis and they modulate the expression of the myogenic regulatory...
Four SIX homeoproteins display a combinatorial expression throughout embryonic developmental myogenesis and they modulate the expression of the myogenic regulatory factors. Here, we provide a deep characterization of their role in distinct mouse developmental territories. We showed, at the hypaxial level, that the Six1:Six4 double knockout (dKO) somitic precursor cells adopt a smooth muscle fate and lose their myogenic identity. At the epaxial level, we demonstrated by the analysis of Six quadruple KO (qKO) embryos, that SIX are required for fetal myogenesis, and for the maintenance of PAX7+ progenitor cells, which differentiated prematurely and are lost by the end of fetal development in qKO embryos. Finally, we showed that Six1 and Six2 are required to establish craniofacial myogenesis by controlling the expression of Myf5. We have thus described an unknown role for SIX proteins in the control of myogenesis at different embryonic levels and refined their involvement in the genetic cascades operating at the head level and in the genesis of myogenic stem cells.
Topics: Mice; Animals; Homeodomain Proteins; Cell Differentiation; Somites; Muscle Development; Gene Expression Regulation, Developmental; Muscle, Skeletal
PubMed: 37267426
DOI: 10.1371/journal.pgen.1010781 -
Journal of Animal Science Nov 2022Although it has long been known that growth media withdrawal is a prerequisite for myoblast differentiation and fusion, the underpinning molecular mechanism remains...
Although it has long been known that growth media withdrawal is a prerequisite for myoblast differentiation and fusion, the underpinning molecular mechanism remains somewhat elusive. Using isolated porcine muscle satellite cells (SCs) as the model, we show elevated O-GlcNAcylation by O-GlcNAcase (OGA) inhibition impaired SC differentiation (D5 P < 0.0001) but had unnoticeable impacts on SC proliferation. To explore the mechanism of this phenotype, we examined the expression of the transcription factor myogenin, a master switch of myogenesis, and found its expression was downregulated by elevated O-GlcNAcylation. Because insulin/IGF-1/Akt axis is a strong promoter of myoblast fusion, we measured the phosphorylated Akt and found that hyper O-GlcNAcylation inhibited Akt phosphorylation, implying OGA inhibition may also work through interfering with this critical differentiation-promoting pathway. In contrast, inhibition of O-GlcNAc transferase (OGT) by its specific inhibitor had little impact on either myoblast proliferation or differentiation (P > 0.05). To confirm these in vitro findings, we used chemical-induced muscle injury in the pig as a model to study muscle regenerative myogenesis and showed how O-GlcNAcylation functions in this process. We show a significant decrease in muscle fiber cross sectional area (CSA) when OGA is inhibited (P < 0.05), compared to nondamaged muscle, and a significant decrease compared to control and OGT inhibited muscle (P < 0.05), indicating a significant impairment in porcine muscle regeneration in vivo. Together, the in vitro and in vivo data suggest that O-GlcNAcylation may serve as a nutrient sensor during SC differentiation by gauging cellular nutrient availability and translating these signals into cellular responses. Given the importance of nutrition availability in lean muscle growth, our findings may have significant implications on how muscle growth is regulated in agriculturally important animals.
Topics: Animals; Swine; Proto-Oncogene Proteins c-akt; Muscle Development; Myoblasts; Cell Differentiation; Phosphorylation
PubMed: 36219104
DOI: 10.1093/jas/skac326 -
Matrix Biology : Journal of the... Jun 2023Myogenesis is the process that generates multinucleated contractile myofibers from muscle stem cells during skeletal muscle development and regeneration. Myogenesis is...
Myogenesis is the process that generates multinucleated contractile myofibers from muscle stem cells during skeletal muscle development and regeneration. Myogenesis is governed by myogenic regulatory transcription factors, including MYOD1. Here, we identified the secreted matricellular protein ADAMTS-like 2 (ADAMTSL2) as part of a Wnt-dependent positive feedback loop, which augmented or sustained MYOD1 expression and thus promoted myoblast differentiation. ADAMTSL2 depletion resulted in severe retardation of myoblast differentiation in vitro and its ablation in myogenic precursor cells resulted in aberrant skeletal muscle architecture. Mechanistically, ADAMTSL2 potentiated WNT signaling by binding to WNT ligands and WNT receptors. We identified the WNT-binding ADAMTSL2 peptide, which was sufficient to promote myogenesis in vitro. Since ADAMTSL2 was previously described as a negative regulator of TGFβ signaling in fibroblasts, ADAMTSL2 now emerges as a signaling hub that could integrate WNT, TGFβ and potentially other signaling pathways within the dynamic microenvironment of differentiating myoblasts during skeletal muscle development and regeneration.
Topics: Cell Differentiation; Muscle Development; Muscle, Skeletal; Satellite Cells, Skeletal Muscle; Transforming Growth Factor beta; Wnt Signaling Pathway; Humans; Mice; Animals
PubMed: 37187448
DOI: 10.1016/j.matbio.2023.05.003 -
Biochimica Et Biophysica Acta.... Feb 2022Skeletal muscles represent a complex and highly organised tissue responsible for all voluntary body movements. Developed through an intricate and tightly controlled... (Review)
Review
Skeletal muscles represent a complex and highly organised tissue responsible for all voluntary body movements. Developed through an intricate and tightly controlled process known as myogenesis, muscles form early in development and are maintained throughout life. Due to the constant stresses that muscles are subjected to, skeletal muscles maintain a complex course of regeneration to both replace and repair damaged myofibers and to form new functional myofibers. This process, made possible by a pool of resident muscle stem cells, termed satellite cells, and controlled by an array of transcription factors, is additionally reliant on a diverse range of cell adhesion molecules and the numerous signaling cascades that they initiate. This article will review the literature surrounding adhesion molecules and their roles in skeletal muscle myogenesis and repair.
Topics: Animals; Cell Adhesion; Cell Adhesion Molecules; Cell Differentiation; Humans; Muscle Development; Regeneration; Satellite Cells, Skeletal Muscle; Signal Transduction
PubMed: 34763027
DOI: 10.1016/j.bbamcr.2021.119170 -
International Journal of Molecular... Mar 2021Circular RNA (circRNA) is a kind of novel endogenous noncoding RNA formed through back-splicing of mRNA precursor. The biogenesis, degradation, nucleus-cytoplasm... (Review)
Review
Circular RNA (circRNA) is a kind of novel endogenous noncoding RNA formed through back-splicing of mRNA precursor. The biogenesis, degradation, nucleus-cytoplasm transport, location, and even translation of circRNA are controlled by RNA-binding proteins (RBPs). Therefore, circRNAs and the chaperoned RBPs play critical roles in biological functions that significantly contribute to normal animal development and disease. In this review, we systematically characterize the possible molecular mechanism of circRNA-protein interactions, summarize the latest research on circRNA-protein interactions in muscle development and myocardial disease, and discuss the future application of circRNA in treating muscle diseases. Finally, we provide several valid prediction methods and experimental verification approaches. Our review reveals the significance of circRNAs and their protein chaperones and provides a reference for further study in this field.
Topics: Animals; Disease Susceptibility; Gene Expression Regulation; Humans; Muscle Development; RNA Editing; RNA Transport; RNA, Circular; RNA, Messenger; RNA-Binding Proteins
PubMed: 33806945
DOI: 10.3390/ijms22063262 -
Methods in Cell Biology 2022Skeletal muscle is a highly regenerative tissue that can efficiently recover from various damages caused by injuries and excessive exercises. In adult muscle, stem cells...
Skeletal muscle is a highly regenerative tissue that can efficiently recover from various damages caused by injuries and excessive exercises. In adult muscle, stem cells termed satellite cells are mitotically quiescent but activated upon muscle damages to enter the cell cycle as myogenic precursor cells or myoblasts. After several rounds of cell cycles, they exist the cycle and fuse to each other to form multinucleated myotubes, and eventually mature to become contractile myofibers. Satellite cells can be readily isolated from mouse skeletal muscle with enzymatic digestion and magnetic separation with antibodies against specific surface markers. C2C12 cells are an immortalized mouse myoblast cell line that is commercially available and more readily expandable than primary myoblasts. Both primary myoblasts and C2C12 cells have been extensively used as useful in vitro models for myogenic differentiation. Proper examination of this process requires monitoring specific protein expression in subcellular compartments, which can be accomplished through immunofluorescence staining. This chapter describes the workflow for the isolation of satellite cells from mouse skeletal muscle and subsequent immunofluorescence staining to assess the proliferation and differentiation of primary myoblasts and C2C12 cells.
Topics: Animals; Cell Differentiation; Fluorescent Antibody Technique; Mice; Muscle Development; Muscle, Skeletal; Myoblasts; Staining and Labeling
PubMed: 35811095
DOI: 10.1016/bs.mcb.2022.02.010 -
Nature Communications Jul 2023Muscle stem cells, the engine of muscle repair, are affected in myotonic dystrophy type 1 (DM1); however, the underlying molecular mechanism and the impact on the...
Muscle stem cells, the engine of muscle repair, are affected in myotonic dystrophy type 1 (DM1); however, the underlying molecular mechanism and the impact on the disease severity are still elusive. Here, we show using patients' samples that muscle stem cells/myoblasts exhibit signs of cellular senescence in vitro and in situ. Single cell RNAseq uncovers a subset of senescent myoblasts expressing high levels of genes related to the senescence-associated secretory phenotype (SASP). We show that the levels of interleukin-6, a prominent SASP cytokine, in the serum of DM1 patients correlate with muscle weakness and functional capacity limitations. Drug screening revealed that the senolytic BCL-XL inhibitor (A1155463) can specifically remove senescent DM1 myoblasts by inducing their apoptosis. Clearance of senescent cells reduced the expression of SASP, which rescued the proliferation and differentiation capacity of DM1 myoblasts in vitro and enhanced their engraftment following transplantation in vivo. Altogether, this study identifies the pathogenic mechanism associated with muscle stem cell defects in DM1 and opens a therapeutic avenue that targets these defective cells to restore myogenesis.
Topics: Humans; Myotonic Dystrophy; Senotherapeutics; Muscle Fibers, Skeletal; Satellite Cells, Skeletal Muscle; Muscle Development
PubMed: 37468473
DOI: 10.1038/s41467-023-39663-3 -
Experimental Cell Research Feb 2022Human pluripotent stem cells (hPSCs) provide a human model for developmental myogenesis, disease modeling and development of therapeutics. Differentiation of hPSCs into... (Review)
Review
Human pluripotent stem cells (hPSCs) provide a human model for developmental myogenesis, disease modeling and development of therapeutics. Differentiation of hPSCs into muscle stem cells has the potential to provide a cell-based therapy for many skeletal muscle wasting diseases. This review describes the current state of hPSCs towards recapitulating human myogenesis ex vivo, considerations of stem cell and progenitor cell state as well as function for future use of hPSC-derived muscle cells in regenerative medicine.
Topics: Cell Differentiation; Humans; Models, Biological; Muscle Development; Muscle, Skeletal; Myoblasts, Skeletal; PAX7 Transcription Factor; Pluripotent Stem Cells; Satellite Cells, Skeletal Muscle
PubMed: 34973262
DOI: 10.1016/j.yexcr.2021.112990 -
Experimental Cell Research Dec 2021Adult skeletal muscle regenerates completely after a damage, thanks to the satellite cells, or muscle stem cells (MuSCs), that implement the adult myogenic program. This... (Review)
Review
Adult skeletal muscle regenerates completely after a damage, thanks to the satellite cells, or muscle stem cells (MuSCs), that implement the adult myogenic program. This program is sustained by both robust intrinsic mechanisms and extrinsic cues coming from the close neighborhood of MuSCs during muscle regeneration. Among the various cell types present in the regenerating muscle, immune cells, and particularly macrophages, exert numerous functions and provide sequential transient niches to support the myogenic program. The adequate orchestration of the delivery of these cues ensures efficient muscle regeneration and full functional recovery. The situation is very different in muscular dystrophies where asynchronous and permanent microinjuries occur, triggering contradictory regenerating cues at the same time in a specific area, that lead to chronic inflammation and fibrogenesis. Here we review the beneficial effects that leukocytes, and particularly macrophages, exert on their neighboring cells during skeletal muscle regeneration after an acute injury. Then, the more complicated (and less beneficial) roles of leukocytes during muscular dystrophies are presented. Finally, we discuss how the inflammatory compartment may be a target to improve muscle regeneration in both acute muscle injury and muscle diseases.
Topics: Animals; Cell Differentiation; Humans; Inflammation; Macrophages; Muscle Development; Muscle, Skeletal; Regeneration; Wound Healing
PubMed: 34736921
DOI: 10.1016/j.yexcr.2021.112905 -
Cellular and Molecular Life Sciences :... Aug 2022Although 5-methylcytosine (mC) has been identified as a novel and abundant mRNA modification and associated with energy metabolism, its regulation function in adipose...
Although 5-methylcytosine (mC) has been identified as a novel and abundant mRNA modification and associated with energy metabolism, its regulation function in adipose tissue and skeletal muscle is still limited. This study aimed at investigating the effect of mRNA mC on adipogenesis and myogenesis using Jinhua pigs (J), Yorkshire pigs (Y) and their hybrids Yorkshire-Jinhua pigs (YJ). We found that Y grow faster than J and YJ, while fatness-related characteristics observed in Y were lower than those of J and YJ. Besides, total mRNA mC levels and expression rates of NSUN2 were higher both in backfat layer (BL) and longissimus dorsi muscle (LDM) of Y compared to J and YJ, suggesting that higher mRNA mC levels positively correlate with lower fat and higher muscle mass. RNA bisulfite sequencing profiling of mC revealed tissue-specific and dynamic features in pigs. Functionally, hyper-methylated mC-containing genes were enriched in pathways linked to impaired adipogenesis and enhanced myogenesis. In in vitro, mC inhibited lipid accumulation and promoted myogenic differentiation. Furthermore, YBX2 and SMO were identified as mC targets. Mechanistically, YBX2 and SMO mRNAs with mC modification were recognized and exported into the cytoplasm from the nucleus by ALYREF, thus leading to increased YBX2 and SMO protein expression and thereby inhibiting adipogenesis and promoting myogenesis, respectively. Our work uncovered the critical role of mRNA mC in regulating adipogenesis and myogenesis via ALYREF-mC-YBX2 and ALYREF-mC-SMO manners, providing a potential therapeutic target in the prevention and treatment of obesity, skeletal muscle dysfunction and metabolic disorder diseases.
Topics: Adipogenesis; Animals; Muscle Development; RNA Transport; RNA, Messenger; RNA-Binding Proteins; Swine
PubMed: 35962235
DOI: 10.1007/s00018-022-04474-0