Chemokine-like receptor 1 regulates skeletal muscle cell myogenesis

The chemokine-like receptor-1 (CMKLR1) is a G protein-coupled receptor that is activated by chemerin, a secreted plasma leukocyte attractant and adipokine. Previous studies identified that CMKLR1 is expressed in skeletal muscle in a stage-specific fashion during embryogenesis and in adult mice; however, its function in skeletal muscle remains unclear. Based on the established function of CMKLR1 in cell migration and differentiation, we investigated the hypothesis that CMKLR1 regulates the differentiation of myoblasts into myotubes. In C2C12 mouse myoblasts, CMKLR1 expression increased threefold with differentiation into multinucleated myotubes. Decreasing CMKLR1 expression by adenoviral-delivered small-hairpin RNA (shRNA) impaired the differentiation of C2C12 myoblasts into mature myotubes and reduced the mRNA expression of myogenic regulatory factors myogenin and MyoD while increasing Myf5 and Mrf4. At embryonic day 12.5 (E12.5), CMKLR1 knockout (CMKLR1−/−) mice appeared developmentally delayed and displayed significantly lower wet weights and a considerably diminished myotomal component of somites as revealed by immunolocalization of myosin heavy chain protein compared with wild-type (CMKLR1+/+) mouse embryos. These changes were associated with increased Myf5 and decreased MyoD protein expression in the somites of E12.5 CMKLR1−/− mouse embryos. Adult male CMKLR1−/− mice had significantly reduced bone-free lean mass and weighed less than the CMKLR1+/+ mice. We conclude that CMKLR1 is essential for myogenic differentiation of C2C12 cells in vitro, and the CMKLR1 null mice have a subtle skeletal muscle deficit beginning from embryonic life that persists during postnatal life.

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Conditional Deletion of Dicer in Adult Mice Impairs Skeletal Muscle Regeneration

International Journal of Molecular Sciences ◽

10.3390/ijms20225686 ◽

2019 ◽

Vol 20 (22) ◽

pp. 5686 ◽

Cited By ~ 2

Author(s):

Satoshi Oikawa ◽

Minjung Lee ◽

Takayuki Akimoto

Keyword(s):

Skeletal Muscle ◽

Muscle Regeneration ◽

Myogenic Differentiation ◽

Tibialis Anterior Muscle ◽

Critical Factor ◽

Skeletal Muscle Regeneration ◽

Small Noncoding Rnas ◽

Adult Mice

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.

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Spontaneous myogenic differentiation of Flk-1-positive cells from adult pancreas and other nonmuscle tissues

AJP Cell Physiology ◽

10.1152/ajpcell.00383.2007 ◽

2008 ◽

Vol 294 (2) ◽

pp. C604-C612 ◽

Cited By ~ 6

Author(s):

Giuliana Di Rocco ◽

Alessandra Tritarelli ◽

Gabriele Toietta ◽

Ilaria Gatto ◽

Maria Grazia Iachininoto ◽

...

Keyword(s):

Skeletal Muscle ◽

Myogenic Differentiation ◽

Small Subset ◽

Myogenic Cells ◽

Adult Mice ◽

Primary Myoblasts ◽

Thymic Medulla ◽

First Time

At the embryonic or fetal stages, autonomously myogenic cells (AMCs), i.e., cells able to spontaneously differentiate into skeletal myotubes, have been identified from several different sites other than skeletal muscle, including the vascular compartment. However, in the adult animal, AMCs from skeletal muscle-devoid tissues have been described in only two cases. One is represented by thymic myoid cells, a restricted population of committed myogenic progenitors of unknown derivation present in the thymic medulla; the other is represented by a small subset of adipose tissue-associated cells, which we recently identified. In the present study we report, for the first time, the presence of spontaneously differentiating myogenic precursors in the pancreas and in other skeletal muscle-devoid organs such as spleen and stomach, as well as in the periaortic tissue of adult mice. Immunomagnetic selection procedures indicate that AMCs derive from Flk-1+ progenitors. Individual clones of myogenic cells from nonmuscle organs are morphologically and functionally indistinguishable from skeletal muscle-derived primary myoblasts. Moreover, they can be induced to proliferate in vitro and are able to participate in muscle regeneration in vivo. Thus, we provide evidence that fully competent myogenic progenitors can be derived from the Flk-1+ compartment of several adult tissues that are embryologically unrelated to skeletal muscle.

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EphA7 promotes myogenic differentiation via cell-cell contact

eLife ◽

10.7554/elife.53689 ◽

2020 ◽

Vol 9 ◽

Author(s):

Laura L Arnold ◽

Alessandra Cecchini ◽

Danny A Stark ◽

Jacqueline Ihnat ◽

Rebecca N Craigg ◽

...

Keyword(s):

Skeletal Muscle ◽

Muscle Regeneration ◽

Muscle Development ◽

Myogenic Differentiation ◽

Cell Contact ◽

Postnatal Life ◽

Differentiation Markers ◽

Hindlimb Muscles

The conversion of proliferating skeletal muscle precursors (myoblasts) to terminally-differentiated myocytes is a critical step in skeletal muscle development and repair. We show that EphA7, a juxtacrine signaling receptor, is expressed on myocytes during embryonic and fetal myogenesis and on nascent myofibers during muscle regeneration in vivo. In EphA7-/- mice, hindlimb muscles possess fewer myofibers at birth, and those myofibers are reduced in size and have fewer myonuclei and reduced overall numbers of precursor cells throughout postnatal life. Adult EphA7-/- mice have reduced numbers of satellite cells and exhibit delayed and protracted muscle regeneration, and satellite cell-derived myogenic cells from EphA7-/- mice are delayed in their expression of differentiation markers in vitro. Exogenous EphA7 extracellular domain will rescue the null phenotype in vitro, and will also enhance commitment to differentiation in WT cells. We propose a model in which EphA7 expression on differentiated myocytes promotes commitment of adjacent myoblasts to terminal differentiation.

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The LIM domain protein nTRIP6 modulates the dynamics of myogenic differentiation

Scientific Reports ◽

10.1038/s41598-021-92331-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Tannaz Norizadeh Abbariki ◽

Zita Gonda ◽

Denise Kemler ◽

Pavel Urbanek ◽

Tabea Wagner ◽

...

Keyword(s):

Skeletal Muscle ◽

Satellite Cells ◽

Muscle Regeneration ◽

Myogenic Differentiation ◽

Skeletal Muscle Regeneration ◽

Temporal Control ◽

Lim Domain ◽

Lim Domain Protein ◽

Domain Protein

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.

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

International Journal of Molecular Sciences ◽

10.3390/ijms21061965 ◽

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.

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ProNGF/p75NTR Axis Drives Fiber Type Specification by Inducing the Fast-Glycolytic Phenotype in Mouse Skeletal Muscle Cells

Cells ◽

10.3390/cells9102232 ◽

2020 ◽

Vol 9 (10) ◽

pp. 2232

Author(s):

Valentina Pallottini ◽

Mayra Colardo ◽

Claudia Tonini ◽

Noemi Martella ◽

Georgios Strimpakos ◽

...

Keyword(s):

Skeletal Muscle ◽

Myosin Heavy Chain ◽

Heavy Chain ◽

Myogenic Differentiation ◽

Fiber Type ◽

Pcr Analysis ◽

Mdx Mouse ◽

Mdx Mice ◽

Muscle Physiology

Despite its undisputable role in the homeostatic regulation of the nervous system, the nerve growth factor (NGF) also governs the relevant cellular processes in other tissues and organs. In this study, we aimed at assessing the expression and the putative involvement of NGF signaling in skeletal muscle physiology. To reach this objective, we employed satellite cell-derived myoblasts as an in vitro culture model. In vivo experiments were performed on Tibialis anterior from wild-type mice and an mdx mouse model of Duchenne muscular dystrophy. Targets of interest were mainly assessed by means of morphological, Western blot and qRT-PCR analysis. The results show that proNGF is involved in myogenic differentiation. Importantly, the proNGF/p75NTR pathway orchestrates a slow-to-fast fiber type transition by counteracting the expression of slow myosin heavy chain and that of oxidative markers. Concurrently, proNGF/p75NTR activation facilitates the induction of fast myosin heavy chain and of fast/glycolytic markers. Furthermore, we also provided evidence that the oxidative metabolism is impaired in mdx mice, and that these alterations are paralleled by a prominent buildup of proNGF and p75NTR. These findings underline that the proNGF/p75NTR pathway may play a crucial role in fiber type determination and suggest its prospective modulation as an innovative therapeutic approach to counteract muscle disorders.

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Arachidonic acid supplementation enhances in vitro skeletal muscle cell growth via a COX-2-dependent pathway

AJP Cell Physiology ◽

10.1152/ajpcell.00038.2012 ◽

2013 ◽

Vol 304 (1) ◽

pp. C56-C67 ◽

Cited By ~ 42

Author(s):

James F. Markworth ◽

David Cameron-Smith

Keyword(s):

Skeletal Muscle ◽

Arachidonic Acid ◽

Cell Growth ◽

Muscle Cell ◽

Myogenic Differentiation ◽

Skeletal Muscle Cell ◽

Diverse Range ◽

Cox 2 ◽

Dependent Pathway

Arachidonic acid (AA) is the metabolic precursor to a diverse range of downstream bioactive lipid mediators. A positive or negative influence of individual eicosanoid species [e.g., prostaglandins (PGs), leukotrienes, and hydroxyeicosatetraenoic acids] has been implicated in skeletal muscle cell growth and development. The collective role of AA-derived metabolites in physiological states of skeletal muscle growth/atrophy remains unclear. The present study aimed to determine the direct effect of free AA supplementation and subsequent eicosanoid biosynthesis on skeletal myocyte growth in vitro . C2C12 (mouse) skeletal myocytes induced to differentiate with supplemental AA exhibited dose-dependent increases in the size, myonuclear content, and protein accretion of developing myotubes, independent of changes in cell density or the rate/extent of myogenic differentiation. Nonselective (indomethacin) or cyclooxygenase 2 (COX-2)-selective (NS-398) nonsteroidal anti-inflammatory drugs blunted basal myogenesis, an effect that was amplified in the presence of supplemental free AA substrate. The stimulatory effects of AA persisted in preexisting myotubes via a COX-2-dependent (NS-389-sensitive) pathway, specifically implying dependency on downstream PG biosynthesis. AA-stimulated growth was associated with markedly increased secretion of PGF2α and PGE2; however, incubation of myocytes with PG-rich conditioned medium failed to mimic the effects of direct AA supplementation. In vitro AA supplementation stimulates PG release and skeletal muscle cell hypertrophy via a COX-2-dependent pathway.

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Modulation of HOXA9 after skeletal muscle denervation and reinnervation

10.21203/rs.2.22314/v1 ◽

2020 ◽

Author(s):

Xiaomei Lu ◽

Bingsheng Liang ◽

Shuaijie Li ◽

Zhi Chen ◽

Wenkai Chang

Keyword(s):

Skeletal Muscle ◽

Muscle Atrophy ◽

Satellite Cells ◽

Gastrocnemius Muscle ◽

Myogenic Differentiation ◽

Cell Activity ◽

Sham Operation ◽

Differentiation Potential ◽

Stem Cell Activity

Abstract Background HOXA9 (Homeobox A9), whose expression is promoted by MLL1 (Mixed Lineage Leukemia 1) and WDR5 (WD-40 repeat protein 5), is a homeodomain-containing transcription factor which plays an essential role in regulating stem cell activity. HOXA9 inhibits regeneration of skeletal muscle and delays the recovery after muscle wound in aged mice, but is little known in denervated/reinnervated muscles. Methods we performed detailed time-process expression analysis on HOXA9 and its promotors, MLL1 and WDR5, in the rat gastrocnemius muscle after three types of sciatic nerve surgeries: nerve transection (denervation); end-to-end repairing (repairing); and the sham operation. Then the specific mechanisms of Hoxa9 were detected in vitro through primary satellite cells transfected respectively by pIRES2-DsRed2 empty plasmids, pIRES2-DsRed2-HOXA9 plasmids, pPLK/ GFP -Puro empty plasmids, and pPLK/GFP-Puro- HOXA9 shRNA plasmids. Results We found that HOXA9 expression was synchronous with the severity of muscle atrophy, as well as the upregulation of MLL1 and WDR5 associated with the denervation state to some extent. Indeed, experiments with primary satellite cells revealed that HOXA9 inhibited myogenic differentiation, but not destroy the differentiation potential, influenced the best-known atrophic pathways, and promoted apoptosis. Conclusion HOXA9 may play a pro-atrophic role in denervated muscle atrophy.

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Persistent COUP-TFII Expression Underlies the Myopathy and Impaired Muscle Regeneration Observed in Resistance to Thyroid Hormone-Alpha

Journal of the Endocrine Society ◽

10.1210/jendso/bvab048.1658 ◽

2021 ◽

Vol 5 (Supplement_1) ◽

pp. A814-A814

Author(s):

Paola Aguiari ◽

Yan-Yun Liu ◽

Astgik Petrosyan ◽

Sheue-Yann Cheng ◽

Gregory A Brent ◽

...

Keyword(s):

Skeletal Muscle ◽

Thyroid Hormone ◽

Muscle Regeneration ◽

Myogenic Differentiation ◽

Skeletal Muscle Regeneration ◽

Hormone Signaling ◽

Muscle Loss ◽

Resistance To Thyroid Hormone ◽

Skeletal Muscle Loss

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.

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Modulation of HOXA9 after skeletal muscle denervation and reinnervation

AJP Cell Physiology ◽

10.1152/ajpcell.00055.2020 ◽

2020 ◽

Vol 318 (6) ◽

pp. C1154-C1165

Author(s):

Xiaomei Lu ◽

Bingsheng Liang ◽

Shuaijie Li ◽

Zhi Chen ◽

Wenkai Chang

Keyword(s):

Skeletal Muscle ◽

Muscle Atrophy ◽

Satellite Cells ◽

Myogenic Differentiation ◽

Cell Activity ◽

Skeletal Muscle Regeneration ◽

Sham Operation ◽

Denervated Muscle ◽

Differentiation Potential

Homeobox A9 (HOXA9), the expression of which is promoted by mixed lineage leukemia 1 (MLL1) and WD-40 repeat protein 5 (WDR5), is a homeodomain-containing transcription factor that plays an essential role in regulating stem cell activity. HOXA9 has been found to inhibit skeletal muscle regeneration and delay recovery after muscle wounding in aged mice, but little is known about its role in denervated/reinnervated muscles. We performed detailed time-dependent expression analyses of HOXA9 and its promoters, MLL1 and WDR5, in rat gastrocnemius muscles after the following three types of sciatic nerve surgeries: nerve transection (denervation), end-to-end repair (repair), and sham operation (sham). Then, the specific mechanisms of HOXA9 were detected in vitro by transfecting primary satellite cells with empty pIRES2-DsRed2, pIRES2-DsRed2-HOXA9, empty pPLK/GFP-Puro, and pPLK/GFP-Puro-HOXA9 small hairpin RNA (shRNA) plasmids. We found, for the first time, that HOXA9 protein expression simultaneously increased with increasing denervated muscle atrophy severity and that upregulated MLL1 and WDR5 expression was partly associated with denervation. Indeed, in vitro experiments revealed that HOXA9 inhibited myogenic differentiation, affected the best known atrophic signaling pathways, and promoted apoptosis but did not eliminate the differentiation potential of primary satellite cells. HOXA9 may promote denervated muscle atrophy by regulating the activity of satellite cells.

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