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 ◽  
...  

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.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tannaz Norizadeh Abbariki ◽  
Zita Gonda ◽  
Denise Kemler ◽  
Pavel Urbanek ◽  
Tabea Wagner ◽  
...  

AbstractThe process of myogenesis which operates during skeletal muscle regeneration involves the activation of muscle stem cells, the so-called satellite cells. These then give rise to proliferating progenitors, the myoblasts which subsequently exit the cell cycle and differentiate into committed precursors, the myocytes. Ultimately, the fusion of myocytes leads to myofiber formation. Here we reveal a role for the transcriptional co-regulator nTRIP6, the nuclear isoform of the LIM-domain protein TRIP6, in the temporal control of myogenesis. In an in vitro model of myogenesis, the expression of nTRIP6 is transiently up-regulated at the transition between proliferation and differentiation, whereas that of the cytosolic isoform TRIP6 is not altered. Selectively blocking nTRIP6 function results in accelerated early differentiation followed by deregulated late differentiation and fusion. Thus, the transient increase in nTRIP6 expression appears to prevent premature differentiation. Accordingly, knocking out the Trip6 gene in satellite cells leads to deregulated skeletal muscle regeneration dynamics in the mouse. Thus, dynamic changes in nTRIP6 expression contributes to the temporal control of myogenesis.


2019 ◽  
Vol 20 (22) ◽  
pp. 5686 ◽  
Author(s):  
Satoshi Oikawa ◽  
Minjung Lee ◽  
Takayuki Akimoto

Skeletal muscle has a remarkable regenerative capacity, which is orchestrated by multiple processes, including the proliferation, fusion, and differentiation of the resident stem cells in muscle. MicroRNAs (miRNAs) are small noncoding RNAs that mediate the translational repression or degradation of mRNA to regulate diverse biological functions. Previous studies have suggested that several miRNAs play important roles in myoblast proliferation and differentiation in vitro. However, their potential roles in skeletal muscle regeneration in vivo have not been fully established. In this study, we generated a mouse in which the Dicer gene, which encodes an enzyme essential in miRNA processing, was knocked out in a tamoxifen-inducible way (iDicer KO mouse) and determined its regenerative potential after cardiotoxin-induced acute muscle injury. Dicer mRNA expression was significantly reduced in the tibialis anterior muscle of the iDicer KO mice, whereas the expression of muscle-enriched miRNAs was only slightly reduced in the Dicer-deficient muscles. After cardiotoxin injection, the iDicer KO mice showed impaired muscle regeneration. We also demonstrated that the number of PAX7+ cells, cell proliferation, and the myogenic differentiation capacity of the primary myoblasts did not differ between the wild-type and the iDicer KO mice. Taken together, these data demonstrate that Dicer is a critical factor for 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 ◽  
...  

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.


2002 ◽  
Vol 50 (12) ◽  
pp. 1579-1589 ◽  
Author(s):  
Katsuya Kami ◽  
Emiko Senba

Although growth factors and cytokines play critical roles in skeletal muscle regeneration, intracellular signaling molecules that are activated by these factors in regenerating muscles have been not elucidated. Several lines of evidence suggest that leukemia inhibitory factor (LIF) is an important cytokine for the proliferation and survival of myoblasts in vitro and acceleration of skeletal muscle regeneration. To elucidate the role of LIF signaling in regenerative responses of skeletal muscles, we examined the spatial and temporal activation patterns of an LIF-associated signaling molecule, the signal transducer and activator transcription 3 (STAT3) proteins in regenerating rat skeletal muscles induced by crush injury. At the early stage of regeneration, activated STAT3 proteins were first detected in the nuclei of activated satellite cells and then continued to be activated in proliferating myoblasts expressing both PCNA and MyoD proteins. When muscle regeneration progressed, STAT3 signaling was no longer activated in differentiated myoblasts and myotubes. In addition, activation of STAT3 was also detected in myonuclei within intact sarcolemmas of surviving myofibers that did not show signs of necrosis. These findings suggest that activation of STAT3 signaling is an important molecular event that induces the successful regeneration of injured skeletal muscles.


2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A814-A814
Author(s):  
Paola Aguiari ◽  
Yan-Yun Liu ◽  
Astgik Petrosyan ◽  
Sheue-Yann Cheng ◽  
Gregory A Brent ◽  
...  

Abstract Myopathic changes, including muscular dystrophy and weakness, are commonly described in hypothyroid and hyperthyroid patients. Thyroid hormone signaling, via activation of thyroid nuclear receptor alpha (THRA), plays an essential role in maintaining muscle mass, function, and regeneration. A mouse model of resistance to thyroid hormone carrying a frameshift mutation in the THRA gene (THRA-PV) is associated with accelerated skeletal muscle loss with aging and impaired regeneration after injury(1,2). We previously demonstrated that the expression of nuclear orphan receptor chicken ovalbumin upstream promoter-factor II (COUP-TFII, or Nr2f2) persists during myogenic differentiation in THRA-PV myoblasts and skeletal muscle of aged THRA- PV mice. COUP-TFII is known to regulate myogenesis negatively and has a role in Duchenne-like Muscular Dystrophies(3). COUP-TFII physically and functionally interacts with THRA in primary myoblasts isolated from WT and THRA-PV mice, as demonstrated via co-immunoprecipitation and chromatin-immunoprecipitation. We observed that satellite cells from THRA-PV mice display impaired myoblast proliferation and in vitro myogenic differentiation compared to WT cells. However, the silencing of COUP-TFII expression using siRNA probes restores in vitro myogenic potential of THRA-PV myoblasts and shifts the mRNA expression profile closer to WT myoblasts, with a higher proliferation of myoblasts and a higher number of fully differentiated myotubes after 5 days of myogenic induction. Moreover, RNAseq analysis on myoblasts from THRA-PV mice after COUP-TFII knockdown shows that COUP-TFII silencing reverses the transcriptomic profile of THRA-PV myoblasts and results in reactivation of pathways involved in muscle function and extracellular matrix remodeling/deposition. These findings indicate that the persistent COUP-TFII expression in THRA-PV mice is responsible for the abnormal muscle phenotype. In conclusion, COUP-TFII and THRA cooperate during murine post-natal myogenesis, and COUP-TFII is critical for the accelerated skeletal muscle loss with aging and impaired muscle regeneration after injury in THRA-PV mice. These studies can help increase our knowledge of the mechanisms involved in thyroid hormone signaling during skeletal muscle regeneration, ultimately increasing the possibility of designing more specific treatments for patients with thyroid hormone-induced myopathies. References: 1. Milanesi, A., et al., Endocrinology 2016; 2. Kaneshige, M. et al., Proc Natl Acad Sci U S 2001; 3. Lee HJ, et al, Sci Rep. 2017.


2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Paola Aguiari ◽  
Astgik Petrosyan ◽  
Yan-Yun Liu ◽  
Sheue-Yann Cheng ◽  
Laura Perin ◽  
...  

Abstract Myopathic changes, including muscular dystrophy and weakness, are commonly described in hypothyroid and hyperthyroid patients. Thyroid hormone signaling, via activation of thyroid nuclear receptors (TRs), plays an essential role in the maintenance of muscle mass, function, and regeneration. TRs are ligand-inducible transcription factors expressed in almost all tissues, including skeletal muscle. In a mouse model of Resistance to Thyroid Hormone carrying a frame-shift mutation in the TRα gene (TRα1PV)1,2 we observed skeletal muscle loss with aging and impaired skeletal muscle regeneration after injury. We recently described that TRα interacts with the nuclear orphan receptor Chicken Ovalbumin Upstream Promoter-factor II (COUP-TFII, or NR2F2), which is known to regulate myogenesis negatively and has a role in Duchenne-like Muscular Dystrophies3. We showed that COUP-TFII expression declines with age in WT mice, while the skeletal muscle of TRα1PV mice shows a sustained significantly higher expression of COUP-TFII. Our findings suggest that the TRα/COUP-TFII interaction might mediate the impaired skeletal muscle phenotype observed in TRα1PV mice. To better characterize this interaction, we isolated SC from 10 months old WT and TRα1PV mice and cultured them in vitro using novel methods established within our lab. Using siRNA probes, we next silenced COUP-TFII and characterized the cells via RNA-seq analysis. In vitro, we assessed myoblast differentiation and proliferation using differentiation assays and EdU incorporation. We observed that satellite cells from TRα1PV mice display impaired myoblast proliferation and in vitro myogenic differentiation compared to WT SCs. However, when COUP-TFII was silenced, the myogenic potential of TRα1PV satellite cells was restored, with a higher proliferation of myoblasts and a higher number of fully differentiated myotubes after 4 days of myogenic induction. RNAseq analysis on satellite cells from TRα1PV mice after COUP-TFII knockdown showed upregulation of genes involved in the myogenic pathway, such as Myod1 and Pax7, and of genes in the thyroid hormone signaling, such as Dio2. Ingenuity Pathway Analysis further showed activation of pathways regarding cell growth, differentiation, matrix remodeling along with muscle function, muscle contractility, and muscle contraction. These in vitro results suggest that by silencing COUP-TFII we promote the myogenic pathway and may further rescue the impaired phenotype of TRα1PV mice. These studies can help increase our knowledge of the mechanisms involved in thyroid hormone signaling in skeletal muscle regeneration, which will ultimately increase the possibility of designing more specific treatments for patients with thyroid hormone-induced myopathies. References: 1Milanesi, A., et al, Endocrinology 2016; 2Kaneshige, M. et al, Proc Natl Acad Sci U S 2001; 3Lee HJ, et al, Sci Rep. 2017.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Karolina Archacka ◽  
Iwona Grabowska ◽  
Bartosz Mierzejewski ◽  
Joanna Graffstein ◽  
Alicja Górzyńska ◽  
...  

Abstract Background The skeletal muscle reconstruction occurs thanks to unipotent stem cells, i.e., satellite cells. The satellite cells remain quiescent and localized between myofiber sarcolemma and basal lamina. They are activated in response to muscle injury, proliferate, differentiate into myoblasts, and recreate myofibers. The stem and progenitor cells support skeletal muscle regeneration, which could be disturbed by extensive damage, sarcopenia, cachexia, or genetic diseases like dystrophy. Many lines of evidence showed that the level of oxygen regulates the course of cell proliferation and differentiation. Methods In the present study, we analyzed hypoxia impact on human and pig bone marrow-derived mesenchymal stromal cell (MSC) and mouse myoblast proliferation, differentiation, and fusion. Moreover, the influence of the transplantation of human bone marrow-derived MSCs cultured under hypoxic conditions on skeletal muscle regeneration was studied. Results We showed that bone marrow-derived MSCs increased VEGF expression and improved myogenesis under hypoxic conditions in vitro. Transplantation of hypoxia preconditioned bone marrow-derived MSCs into injured muscles resulted in the improved cell engraftment and formation of new vessels. Conclusions We suggested that SDF-1 and VEGF secreted by hypoxia preconditioned bone marrow-derived MSCs played an essential role in cell engraftment and angiogenesis. Importantly, hypoxia preconditioned bone marrow-derived MSCs more efficiently engrafted injured muscles; however, they did not undergo myogenic differentiation.


2019 ◽  
Vol 10 (10) ◽  
Author(s):  
Yuantong Liu ◽  
Yue Shang ◽  
Zihan Yan ◽  
Hao Li ◽  
Zhen Wang ◽  
...  

Abstract Adult skeletal muscle regeneration after injury depends on normal myoblast function. However, the intrinsic mechanisms for the control of myoblast behaviors are not well defined. Herein, we identified Pim1 kinase as a novel positive regulator of myoblast behaviors in vitro and muscle regeneration in vivo. Specifically, knockdown of Pim1 significantly restrains the proliferation and accelerates the apoptosis of myoblasts in vitro, indicating that Pim1 is critical for myoblast survival and amplification. Meanwhile, we found that Pim1 kinase is increased and translocated from cytoplasm into nucleus during myogenic differentiation. By using Pim1 kinase inhibitor, we proved that inhibition of Pim1 activity prevents myoblast differentiation and fusion, suggesting the necessity of Pim1 kinase activity for proper myogenesis. Mechanistic studies demonstrated that Pim1 kinase interacts with myogenic regulator MyoD and controls its transcriptional activity, inducing the expression of muscle-specific genes, which consequently promotes myogenic differentiation. Additionally, in skeletal muscle injury mouse model, deletion of Pim1 hinders the regeneration of muscle fibers and the recovery of muscle strength. Taken together, our study provides a potential target for the manipulation of myoblast behaviors in vitro and the myoblast-based therapeutics of skeletal muscle injury.


2021 ◽  
Author(s):  
Karolina Archacka ◽  
Iwona Grabowska ◽  
Bartosz Mierzejewski ◽  
Joanna Graffstain ◽  
Alicja Górzyńska ◽  
...  

Abstract Background: The skeletal muscle reconstruction occurs thanks to unipotent stem cells, i.e., satellite cells. The satellite cells remain quiescent and localized between myofiber sarcolemma and basal lamina. They are activated in response to muscle injury, proliferate, differentiate into myoblasts, and recreate myofibers. Many stem and progenitor cells support skeletal muscle regeneration, which could be disturbed by extensive damage, sarcopenia, cachexia, or genetic diseases like dystrophy. Many lines of evidence showed that the level of oxygen regulates the course of cell proliferation and differentiation. Methods: In the present study, we analyzed hypoxic’s impact on human and pig bone marrow-derived mesenchymal stromal cell (MSC) and mouse myoblast proliferation, differentiation, and fusion. Moreover, the influence of the transplantation of human bone marrow-derived MSCs cultured under hypoxic conditions on skeletal muscle regeneration was studied. Results: We showed that bone marrow-derived MSCs increased VEGF expression and improved myogenesis under hypoxic conditions in vitro. Transplantation of hypoxic preconditioned bone marrow-derived MSCs into injured muscles resulted in the improved cell engraftment and formation of new vessels. Conclusions: We suggested that SDF-1 and VEGF secreted by hypoxic preconditioned bone marrow-derived MSCs played an essential role in cell engraftment and angiogenesis. Importantly, hypoxic preconditioned bone marrow-derived MSCs more efficiently engrafted injured muscles, however, they did not undergo myogenic differentiation.


2020 ◽  
Author(s):  
Shi Chen ◽  
Chao Du ◽  
Lilong Pan ◽  
Qian Yang ◽  
Peihe Yu ◽  
...  

Abstract Background: Limb ischemic necrosis is mainly attributed to peripheral arterial disease (PAD). Reducing oxidative stress and promoting damaged skeletal muscle regeneration may be benefit for ischemic limb treatment. Proanthocyanidins (PC) is a powerful antioxidant and free radical scavenger, but little is known about its role and related molecular mechanism in limb ischemic injury. The current study was undertaken to explore its role in the damaged skeletal muscle regeneration both in vitro and vivo, and whether MicroRNAs (miRNAs) involved in this process. Methods: The potential effects of PC on the damaged muscle regeneration were explored in human skeletal muscle satellite cells (HSKMSCs) under hypoxic-ischemic condition and in mice limb ischemia model, then, aberrant expression of miRNAs in ischemic skeletal muscles were determined by microarray analysis, and regulatory mechanism of the specific miRNA on HSKMSCs myogenic differentiation was further investigated by gain and loss of functional experiments. Additionally, the direct target gene was examined by luciferase reporter assay.Results: In mice limb ischemia model, our results revealed that PC reduced oxidative stress level, significantly promoted ischemic limb damaged muscle regeneration and motor function recovery, then, aberrant expression of miRNAs in ischemic skeletal muscles were determined by microarray analysis, combine with the results of the RT-qPCR, the miR-133b-3p was proved to be the specific miRNA. In vitro, our results revealed that PC induced the overexpression of miR-133b to activate the p38-MAPK signal pathway and increased the myogenic differentiation-related molecules expression, which eventually promoted myotubes formation. Furthermore, MKP1 was confirmed a direct target gene of miR-133b.Conclusion: Our results suggest that PC display skeletal muscle protective properties that are mediated by miR-133b /MKP1/ p38-MAPK signal axis, offering a novel therapeutic opportunity for limb ischemic injury.


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