scholarly journals Phospholipase D1 facilitates second-phase myoblast fusion and skeletal muscle regeneration

2015 ◽  
Vol 26 (3) ◽  
pp. 506-517 ◽  
Author(s):  
Shuzhi Teng ◽  
David Stegner ◽  
Qin Chen ◽  
Tsunaki Hongu ◽  
Hiroshi Hasegawa ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Regeneration ◽  
Muscle Development ◽  
Myoblast Fusion ◽  
Skeletal Muscle Regeneration ◽  
Fusion Pore ◽  
Myoblast Differentiation ◽  
Second Phase ◽  
Genetic Ablation ◽  
Phospholipase D1

Myoblast differentiation and fusion is a well-orchestrated multistep process that is essential for skeletal muscle development and regeneration. Phospholipase D1 (PLD1) has been implicated in the initiation of myoblast differentiation in vitro. However, whether PLD1 plays additional roles in myoblast fusion and exerts a function in myogenesis in vivo remains unknown. Here we show that PLD1 expression is up-regulated in myogenic cells during muscle regeneration after cardiotoxin injury and that genetic ablation of PLD1 results in delayed myofiber regeneration. Myoblasts derived from PLD1-null mice or treated with PLD1-specific inhibitor are unable to form mature myotubes, indicating defects in second-phase myoblast fusion. Concomitantly, the PLD1 product phosphatidic acid is transiently detected on the plasma membrane of differentiating myocytes, and its production is inhibited by PLD1 knockdown. Exogenous lysophosphatidylcholine, a key membrane lipid for fusion pore formation, partially rescues fusion defect resulting from PLD1 inhibition. Thus these studies demonstrate a role for PLD1 in myoblast fusion during myogenesis in which PLD1 facilitates the fusion of mononuclear myocytes with nascent myotubes.

scholarly journals Circular RNA profiling of buffalo myoblasts reveals an abundant circPICALM that promotes myoblast differentiation

2020 ◽  
Author(s):  
Mingming Song ◽  
Mengjie Chen ◽  
Kongwei Huang ◽  
Dandan Zhong ◽  
Yaling Chen ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Regeneration ◽  
Muscle Development ◽  
Expression Profiles ◽  
Muscle Growth ◽  
Circular Rna ◽  
Skeletal Muscle Regeneration ◽  
Myoblast Differentiation ◽  
Circular Rnas

Abstract Background Muscle development is a precisely orchestrated and complex process, and circular RNAs (circRNAs) has been demonstrated to play important roles in skeletal muscle growth and development. However, the regulatory functions of circRNA during buffalo muscle developmental processes have not been understood.Results In this study, Ribo-Zero RNA-Seq was performed to investigate the circRNAs expression profiles of proliferated and differentiated buffalo myoblasts. A stringent set of 3,142 circRNAs was finally characterized. Comparing the expression profiles of circRNAs revealed that 110 circRNAs were expressed differentially during myoblast differentiation. We focused on the role of a candidate circRNA, which was named circPICALM based on its host gene PICALM, and was highly (but differentially) expressed in proliferated and differentiated myoblasts. Flow cytometry, EdU incorporation, and Western blotting assays demonstrate that circPICALM promoted myoblasts proliferation and inhibited cells apoptosis. Moreover, overexpression of circPICALM promoted the differentiation of primary buffalo myoblasts. Moreover, circPICALM in vivo stimulated skeletal muscle regeneration in cardiotoxin-induced muscle injury. The RNA pulldown results showed that circPICALM could capture TUBA1B protein, revealing that circPICALM might exert its biological function by binding TUBA1B protein. Conclusions These results demonstrate that the novel non-coding regulator circPICALM induces myoblast differentiation and skeletal muscle regeneration.

scholarly journals Impaired Skeletal Muscle Development and Regeneration in Transglutaminase 2 Knockout Mice

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 3089
Author(s):  
Zsófia Budai ◽  
Nour Al-Zaeed ◽  
Péter Szentesi ◽  
Hajnalka Halász ◽  
László Csernoch ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Regeneration ◽  
Muscle Development ◽  
Tibialis Anterior Muscle ◽  
Transglutaminase 2 ◽  
Myoblast Fusion ◽  
Skeletal Muscle Regeneration ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation ◽  
Inflammatory Phenotype

Skeletal muscle regeneration is triggered by local inflammation and is accompanied by phagocytosis of dead cells at the injury site. Efferocytosis regulates the inflammatory program in macrophages by initiating the conversion of their inflammatory phenotype into the healing one. While pro-inflammatory cytokines induce satellite cell proliferation and differentiation into myoblasts, growth factors, such as GDF3, released by healing macrophages drive myoblast fusion and myotube growth. Therefore, improper efferocytosis may lead to impaired muscle regeneration. Transglutaminase 2 (TG2) is a versatile enzyme participating in efferocytosis. Here, we show that TG2 ablation did not alter the skeletal muscle weights or sizes but led to the generation of small size myofibers and to decreased grip force in TG2 null mice. Following cardiotoxin-induced injury, the size of regenerating fibers was smaller, and the myoblast fusion was delayed in the tibialis anterior muscle of TG2 null mice. Loss of TG2 did not affect the efferocytic capacity of muscle macrophages but delayed their conversion to Ly6C−CD206+, GDF3 expressing cells. Finally, TG2 promoted myoblast fusion in differentiating C2C12 myoblasts. These results indicate that TG2 expressed by both macrophages and myoblasts contributes to proper myoblast fusion, and its ablation leads to impaired muscle development and regeneration in mice.

scholarly journals Kinin-B2 Receptor Activity in Skeletal Muscle Regeneration and Myoblast Differentiation

2018 ◽  
Vol 15 (1) ◽  
pp. 48-58 ◽  
Author(s):  
Janaina M. Alves ◽  
Antonio H. Martins ◽  
Claudiana Lameu ◽  
Talita Glaser ◽  
Nawal M. Boukli ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Regeneration ◽  
Receptor Activity ◽  
Skeletal Muscle Regeneration ◽  
Myoblast Differentiation

scholarly journals Tenogenic Contribution to Skeletal Muscle Regeneration: The Secretome of Scleraxis Overexpressing Mesenchymal Stem Cells Enhances Myogenic Differentiation In Vitro

2020 ◽  
Vol 21 (6) ◽  
pp. 1965
Author(s):  
Maximilian Strenzke ◽  
Paolo Alberton ◽  
Attila Aszodi ◽  
Denitsa Docheva ◽  
Elisabeth Haas ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Regeneration ◽  
Skeletal Muscles ◽  
Myogenic Differentiation ◽  
Muscular Contraction ◽  
Myoblast Fusion ◽  
Skeletal Muscle Regeneration ◽  
Potential Candidate ◽  
Musculoskeletal Tissue

Integrity of the musculoskeletal system is essential for the transfer of muscular contraction force to the associated bones. Tendons and skeletal muscles intertwine, but on a cellular level, the myotendinous junctions (MTJs) display a sharp transition zone with a highly specific molecular adaption. The function of MTJs could go beyond a mere structural role and might include homeostasis of this musculoskeletal tissue compound, thus also being involved in skeletal muscle regeneration. Repair processes recapitulate several developmental mechanisms, and as myotendinous interaction does occur already during development, MTJs could likewise contribute to muscle regeneration. Recent studies identified tendon-related, scleraxis-expressing cells that reside in close proximity to the MTJs and the muscle belly. As the muscle-specific function of these scleraxis positive cells is unknown, we compared the influence of two immortalized mesenchymal stem cell (MSC) lines—differing only by the overexpression of scleraxis—on myoblasts morphology, metabolism, migration, fusion, and alignment. Our results revealed a significant increase in myoblast fusion and metabolic activity when exposed to the secretome derived from scleraxis-overexpressing MSCs. However, we found no significant changes in myoblast migration and myofiber alignment. Further analysis of differentially expressed genes between native MSCs and scleraxis-overexpressing MSCs by RNA sequencing unraveled potential candidate genes, i.e., extracellular matrix (ECM) proteins, transmembrane receptors, or proteases that might enhance myoblast fusion. Our results suggest that musculotendinous interaction is essential for the development and healing of skeletal muscles.

scholarly journals Sox15 Is Required for Skeletal Muscle Regeneration

2004 ◽  
Vol 24 (19) ◽  
pp. 8428-8436 ◽  
Author(s):  
Heon-Jin Lee ◽  
Wolfgang Göring ◽  
Matthias Ochs ◽  
Christian Mühlfeld ◽  
Gerd Steding ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Cell Fate ◽  
Satellite Cells ◽  
Muscle Regeneration ◽  
Muscle Development ◽  
Myogenic Cell ◽  
Skeletal Muscle Regeneration ◽  
Term Survival ◽  
Differentiation Potential ◽  
Cell Lineages

ABSTRACT The Sox genes define a family of transcription factors that play a key role in the determination of cell fate during development. The preferential expression of the Sox15 in the myogenic precursor cells led us to suggest that the Sox15 is involved in the specification of myogenic cell lineages or in the regulation of the fusion of myoblasts to form myotubes during the development and regeneration of skeletal muscle. To identify the physiological function of Sox15 in mice, we disrupted the Sox15 by homologous recombination in mice. Sox15-deficient mice were born at expected ratios, were healthy and fertile, and displayed normal long-term survival rates. Histological analysis revealed the normal ultrastructure of myofibers and the presence of comparable amounts of satellite cells in the skeletal muscles of Sox15−/− animals compared to wild-type animals. These results exclude the role of Sox15 in the development of satellite cells. However, cultured Sox15−/− myoblasts displayed a marked delay in differentiation potential in vitro. Moreover, skeletal muscle regeneration in Sox15−/− mice was attenuated after application of a crush injury. These results suggest a requirement for Sox15 in the myogenic program. Expression analyses of the early myogenic regulated factors MyoD and Myf5 showed the downregulation of the MyoD and upregulation of the Myf5 in Sox15−/− myoblasts. These results show an increased proportion of the Myf5-positive cells and suggest a role for Sox15 in determining the early myogenic cell lineages during skeletal muscle development.

Plasmin activity is required for myogenesis in vitro and skeletal muscle regeneration in vivo

Blood ◽  
2002 ◽  
Vol 99 (8) ◽  
pp. 2835-2844 ◽  
Author(s):  
Mònica Suelves ◽  
Roser López-Alemany ◽  
Frederic Lluı́s ◽  
Gloria Aniorte ◽  
Erika Serrano ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Regeneration ◽  
Myoblast Fusion ◽  
Skeletal Muscle Regeneration ◽  
Wild Type ◽  
Plasmin Activity ◽  
Type Plasminogen Activator ◽  
Deficient Mice

Abstract Plasmin, the primary fibrinolytic enzyme, has a broad substrate spectrum and is implicated in biologic processes dependent upon proteolytic activity, such as tissue remodeling and cell migration. Active plasmin is generated from proteolytic cleavage of the zymogen plasminogen (Plg) by urokinase-type plasminogen activator (uPA) and tissue-type plasminogen activator (tPA). Here, we have investigated the role of plasmin in C2C12 myoblast fusion and differentiation in vitro, as well as in skeletal muscle regeneration in vivo, in wild-type and Plg-deficient mice. Wild-type mice completely repaired experimentally damaged skeletal muscle. In contrast, Plg−/− mice presented a severe regeneration defect with decreased recruitment of blood-derived monocytes and lymphocytes to the site of injury and persistent myotube degeneration. In addition, Plg-deficient mice accumulated fibrin in the degenerating muscle fibers; however, fibrinogen depletion of Plg-deficient mice resulted in a correction of the muscular regeneration defect. Because we found that uPA, but not tPA, was induced in skeletal muscle regeneration, and persistent fibrin deposition was also reproducible in uPA-deficient mice following injury, we propose that fibrinolysis by uPA-dependent plasmin activity plays a fundamental role in skeletal muscle regeneration. In summary, we identify plasmin as a critical component of the mammalian skeletal muscle regeneration process, possibly by preventing intramuscular fibrin accumulation and by contributing to the adequate inflammatory response after injury. Finally, we found that inhibition of plasmin activity with α2-antiplasmin resulted in decreased myoblast fusion and differentiation in vitro. Altogether, these studies demonstrate the requirement of plasmin during myogenesis in vitro and muscle regeneration in vivo.

scholarly journals ARHGEF3 regulates skeletal muscle regeneration and strength through autophagy

2020 ◽  
Author(s):  
Jae-Sung You ◽  
Nilmani Singh ◽  
Adriana Reyes-Ordonez ◽  
Nidhi Khanna ◽  
Zehua Bao ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Regeneration ◽  
Mammalian Target Of Rapamycin ◽  
Akt Signaling ◽  
Skeletal Muscle Regeneration ◽  
Myoblast Differentiation ◽  
Independent Manner ◽  
And Function ◽  
Old Mice

SummarySkeletal muscle regeneration is essential for restoring muscle function upon injury and for the maintenance of muscle health with aging. ARHGEF3, a Rho-specific GEF, negatively regulates myoblast differentiation via mammalian target of rapamycin complex 2 (mTORC2)-Akt signaling in a GEF-independent manner in vitro. Here, we investigated ARHGEF3’s role in skeletal muscle regeneration by creating ARHGEF3 KO mice. These mice exhibited no discernible phenotype under normal conditions. Upon injury, however, ARHGEF3 deficiency enhanced the mass, fiber size and function of regenerating muscles in both young and aged mice. Surprisingly, these effects were not mediated by mTORC2-Akt signaling, but by the GEF activity of ARHGEF3. Furthermore, ARHGEF3 KO promoted muscle regeneration through activation of autophagy, a process that is also critical for maintaining muscle strength. Accordingly, in old mice, ARHGEF3 depletion prevented muscle weakness by restoring autophagy flux. Collectively, our findings identify an unexpected link between ARHGEF3 and autophagy-related muscle pathophysiology.

Abstract 13433: Angiotensin II Type 2 Receptor Regulates Skeletal Myoblast Differentiation: Implications for treatment of Cachexia and Skeletal Muscle Wasting

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Tadashi Yoshida ◽  
Patrice Delafontaine
Keyword(s):  
Skeletal Muscle ◽  
Angiotensin Ii ◽  
Muscle Regeneration ◽  
Muscle Wasting ◽  
Skeletal Muscle Regeneration ◽  
Myoblast Differentiation ◽  
Muscle Physiology ◽  
Ang Ii ◽  
Skeletal Muscle Wasting

Patients with advanced congestive heart failure (CHF) or chronic kidney disease (CKD) often have increased angiotensin II (Ang II) levels and cachexia. We previously demonstrated that Ang II infusion in rodents causes skeletal muscle wasting and decreases muscle regenerative potential via Ang II type 1 receptor (AT1R) signaling, likely contributing to cachexia in CHF and CKD. However, the potential role of Ang II type 2 receptor (AT2R) signaling in skeletal muscle physiology remains unknown. We found that AT2R expression was robustly increased in mouse skeletal myoblasts during differentiation, suggesting that the AT2R plays an important role in skeletal muscle regeneration. To test this hypothesis, we infused mice with AT2R antagonist PD123319 (PD, 30 mg/kg/d) or agonist CGP123319 (CGP, 1 μg/kg/min) during cardiotoxin (CTX)-induced muscle injury and regeneration. PD reduced the size of regenerating myofibers (727.5±54.6 and 516.0±37.0 μm2 in sham and PD, respectively, p<0.05) and expression of the myoblast differentiation markers myogenin and eMyHC (56.9% and 40.2% decrease in PD, respectively. p<0.01), whereas CGP had the opposite effects. siRNA mediated AT2R knockdown in mouse primary myoblasts suppressed the increase of myogenin and desmin, resulting in lowered differentiation. We analyzed changes in phosphoprotein levels in myoblasts after AT2R knockdown by phosphoprotein array and identified multiple changes, including increased phospho-ERK1/2 levels. Importantly, inhibition of ERK1/2 restored normal myoblast differentiation in the setting of AT2R knockdown, suggesting the AT2R positively regulates myoblast differentiation by reducing ERK1/2 activity. Furthermore, we found that skeletal muscle regeneration was reduced (decreased regenerating myofiber size and myogenin/desmin expression) in a mouse myocardial infarction model of CHF, concomitantly with markedly blunted increase of AT2R expression, strongly suggesting that the AT2R plays an important role in the reduction of skeletal muscle function in CHF. These data indicate that AT2R signaling positively regulates myoblast differentiation and potentiates skeletal muscle regeneration, providing a new therapeutic target in wasting disorders such as CHF and CKD.

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