scholarly journals Cell Fusion in Skeletal Muscle: Central Role of NFATC2 in Regulating Muscle Cell Size

Cell Cycle ◽  
2003 ◽  
Vol 2 (5) ◽  
pp. 419-422 ◽  
Author(s):  
Grace K. Pavlath ◽  
Valerie Horsley
2000 ◽  
Vol 149 (3) ◽  
pp. 657-666 ◽  
Author(s):  
Bret B. Friday ◽  
Valerie Horsley ◽  
Grace K. Pavlath

Differentiation of skeletal muscle myoblasts follows an ordered sequence of events: commitment, cell cycle withdrawal, phenotypic differentiation, and finally cell fusion to form multinucleated myotubes. The molecular signaling pathways that regulate the progression are not well understood. Here we investigate the potential role of calcium and the calcium-dependent phosphatase calcineurin in myogenesis. Commitment, phenotypic differentiation, and cell fusion are identified as distinct calcium-regulated steps, based on the extracellular calcium concentration required for the expression of morphological and biochemical markers specific to each of these stages. Furthermore, differentiation is inhibited at the commitment stage by either treatment with the calcineurin inhibitor cyclosporine A (CSA) or expression of CAIN, a physiological inhibitor of calcineurin. Retroviral-mediated gene transfer of a constitutively active form of calcineurin is able to induce myogenesis only in the presence of extracellular calcium, suggesting that multiple calcium-dependent pathways are required for differentiation. The mechanism by which calcineurin initiates differentiation includes transcriptional activation of myogenin, but does not require the participation of NFAT. We conclude that commitment of skeletal muscle cells to differentiation is calcium and calcineurin-dependent, but NFAT-independent.


2014 ◽  
Vol 10 (9) ◽  
pp. 983-989 ◽  
Author(s):  
Wangjun Wu ◽  
Ruihua Huang ◽  
Qinghua Wu ◽  
Pinghua Li ◽  
Jie Chen ◽  
...  

1999 ◽  
Vol 146 (4) ◽  
pp. 893-904 ◽  
Author(s):  
Isao Tachibana ◽  
Martin E. Hemler

The role of transmembrane 4 superfamily (TM4SF) proteins during muscle cell fusion has not been investigated previously. Here we show that the appearance of TM4SF protein, CD9, and the formation of CD9–β1 integrin complexes were both regulated in coordination with murine C2C12 myoblast cell differentiation. Also, anti-CD9 and anti-CD81 monoclonal antibodies substantially inhibited and delayed conversion of C2C12 cells to elongated myotubes, without affecting muscle-specific protein expression. Studies of the human myoblast-derived RD sarcoma cell line further demonstrated that TM4SF proteins have a role during muscle cell fusion. Ectopic expression of CD9 caused a four- to eightfold increase in RD cell syncytia formation, whereas anti-CD9 and anti-CD81 antibodies markedly delayed RD syncytia formation. Finally, anti-CD9 and anti-CD81 monoclonal antibodies triggered apoptotic degeneration of C2C12 cell myotubes after they were formed. In summary, TM4SF proteins such as CD9 and CD81 appear to promote muscle cell fusion and support myotube maintenance.


2020 ◽  
Author(s):  
Ashutosh Kumar ◽  
Litao Xie ◽  
Chau My Ta ◽  
Antentor O Hinton ◽  
Susheel K Gunasekar ◽  
...  

2020 ◽  
Author(s):  
Ruili Liu ◽  
Xianxun Liu ◽  
Kun Yu ◽  
Xuejin Bai ◽  
Yajuan Dong

Abstract Background There is increasing understanding of the possible regulatory role of long non-coding RNAs (LncRNA). Studies on livestock have mainly focused on the regulation of cell differentiation, fat synthesis, and embryonic development. However, there has been little study of skeletal muscle of domestic animals and the potential role of lncRNA. Results RNA samples were collected from longissimus dorsi muscle samples of Shandong black cattle and Luxi cattle and libraries were constructed and sequenced. A total of 1415 transcripts (of which 480 were LncRNAs) were differentially expressed (P < 0.05) in the different breeds, and fourteen of these RNAs were randomly selected and validated by qPCR. We found that the most differentially expressed LncRNAs were found on chromosome 9, with 1164 within 50 kb of a protein-coding gene. In addition, Pearson's correlation coefficients of co-expression levels indicated a potential trans regulatory relationship between the differentially expressed LncRNAs and 43844 mRNAs (r > 0.9). The identified co-expressed mRNAs (MYORG, Dll1, EFNB2, SOX6, MYOCD, and MYLK3) are related to the formation of muscle structure, and enriched in muscle system process, strained muscle cell differentiation, muscle cell development, striated muscle tissue development, calcium signaling, and AMPK signaling. Additionally, we also found that some LncRNAs (LOC112444238, LOC101903367, LOC104975788, LOC112441863, LOC112449549, and LOC101907194) may interact with miRNAs related to cattle muscle growth and development. Based on this, we constructed a LncRNAs-miRNA-mRNA interaction network as the putative basis for biological regulation in cattle skeletal muscle. Interestingly, a candidate differential LncRNA (LOC104975788) and a protein-coding gene (Pax7) contain miR-133a binding sites and binding was confirmed by luciferase reporter assay. LOC104975788 may bind miR-133a competitively with Pax7, thus relieving the inhibitory effect of miR-133a on Pax7 to regulate skeletal muscle development. These results will provide the theoretical basis for further study of LncRNA regulation and activity in different cattle breeds. Conclusions The data obtained in this study were used to predict muscle-related LncRNAs-miRNA-mRNA interaction networks, which can help elucidate the molecular mechanism of cattle muscle development. These results can be used to facilitate livestock breeding and improve livestock production.


2006 ◽  
Vol 103 (19) ◽  
pp. 7315-7320 ◽  
Author(s):  
A. Sotiropoulos ◽  
M. Ohanna ◽  
C. Kedzia ◽  
R. K. Menon ◽  
J. J. Kopchick ◽  
...  

2017 ◽  
Vol 444 (1-2) ◽  
pp. 109-123 ◽  
Author(s):  
Hannah F. Dugdale ◽  
David C. Hughes ◽  
Robert Allan ◽  
Colleen S. Deane ◽  
Christopher R. Coxon ◽  
...  

1997 ◽  
Vol 110 (9) ◽  
pp. 1083-1089 ◽  
Author(s):  
S. Bonavaud ◽  
C. Charriere-Bertrand ◽  
C. Rey ◽  
M.P. Leibovitch ◽  
N. Pedersen ◽  
...  

Urokinase can form a tripartite complex binding urokinase receptor (uPAR) and plasminogen activator inhibitor type-1 (PAI-1), a component of the extracellular matrix (ECM). The components of the tripartite complex are modulated throughout the in vitro myogenic differentiation process. A series of experiments aimed at elucidating the role of the urokinase tripartite complex in the fusion of human myogenic cells were performed in vitro. Myogenic cell fusion was associated with increased cell-associated urokinase-type plasminogen activator (uPA) activity, cell-associated uPAR, and uPAR occupancy. Incubation of cultures with either uPA anticatalytic antibodies, or the amino-terminal fragment of uPA (ATF), which inhibits competitively uPA binding to its receptor, or anti-PAI-1 antibodies, which inhibit uPA binding to PAI-1, resulted in a 30 to 47% decrease in fusion. Incubation of cultures with the plasmin inhibitor aprotinin did not affect fusion. Decreased fusion rates induced by interfering with uPAR/uPA/PAI-1 interactions were not associated with significant changes in mRNA levels of both the myogenic regulatory factor myogenin and its inhibitor of DNA binding, Id. Incubation of cultures with purified uPA resulted in a decrease in fusion, likely due to a competitive inhibition of PAI-1 binding of endogenous uPA. We conclude that muscle cell fusion largely depends on interactions between the members of the urokinase complex (uPAR/uPA/PAI-1), but does not require proteolytic activation of plasmin. Since the intrinsic muscle cell differentiation program appears poorly affected by the state of integrity of the urokinase complex, and since cell migration is a prerequisite for muscle cell fusion in vitro, it is likely that the urokinase system is instrumental in fusion through its connection with the cell migration process. Our results suggest that the urokinase tripartite complex may be involved in cell migration in a non conventional way, playing the role of an adhesion system bridging cell membrane to ECM.


Sign in / Sign up

Export Citation Format

Share Document