Transient expression of the intermediate filament nestin during skeletal muscle development

1993 ◽  
Vol 106 (4) ◽  
pp. 1291-1300 ◽  
Author(s):  
T. Sejersen ◽  
U. Lendahl

It has previously been established that skeletal muscle development is accompanied by changes in the composition of intermediate filaments: vimentin is expressed predominantly in myoblasts and desmin in adult myotubes. We show that the intermediate filament transitions during muscle development are more complex, and involve a transient expression of the recently discovered intermediate filament nestin. Nestin RNA is expressed predominantly early, in a biphasic pattern, and is markedly downregulated in adult rat muscle, whereas desmin RNA becomes more abundant throughout development. Nestin protein was found up to the postnatal myotube stage, where it colocalized with desmin in Z bands. The intracellular distribution of nestin, vimentin and desmin was analysed in the human myogenic cell line G6 before and after in vitro differentiation. Despite its more distant evolutionary and structural relationship to the other two intermediate filaments, nestin formed a cytoplasmic filamentous network indistinguishable from that of desmin and vimentin, both in undifferentiated myoblasts and after differentiation to multinuclear myotubes. In conclusion, our data suggest that nestin is an integrated component of the dynamic intermediate filament network during muscle development and that nestin copolymerizes with desmin and vimentin at stages of coexpression.

Author(s):  
Malte Puchert ◽  
Christian Koch ◽  
Konstanze Zieger ◽  
Jürgen Engele

AbstractThe chemokine, CXCL12, and its receptors, CXCR4 and CXCR7, play pivotal roles during development and maintenance of limb muscles. CXCR7 additionally binds CXCL11, which uses CXCR3 as its prime receptor. Based on this cross-talk, we investigate whether CXCL11 would likewise affect development and/or function of skeletal muscles. Western blotting and immunolabelling demonstrated the developmentally restricted expression of CXCL11 in rat limb muscles, which was contrasted by the continuous expression of its receptors in proliferating and differentiating C2C12 cells as well as in late embryonic to adult rat limb muscle fibres. Consistent with a prime role in muscle formation, functional studies identified CXCL11 as a potent chemoattractant for undifferentiated C2C12 cells and further showed that CXCL11 does neither affect myoblast proliferation and differentiation nor metabolic/catabolic pathways in formed myotubes. The use of selective receptor antagonists unravelled complementary effects of CXCL11 and CXCL12 on C2C12 cell migration, which either require CXCR3/CXCR7 or CXCR4, respectively. Our findings provide new insights into the chemokine network controlling skeletal muscle development and function and, thus, might provide a base for future therapies of muscular diseases.


1996 ◽  
Vol 135 (3) ◽  
pp. 829-835 ◽  
Author(s):  
J T Yang ◽  
T A Rando ◽  
W A Mohler ◽  
H Rayburn ◽  
H M Blau ◽  
...  

It has been suggested, on the basis of immunolocalization studies in vivo and antibody blocking experiments in vitro, that alpha 4 integrins interacting with vascular cell adhesion molecule 1 (VCAM-1) are involved in myogenesis and skeletal muscle development. To test this proposal, we generated embryonic stem (ES) cells homozygous null for the gene encoding the alpha 4 subunit and used them to generate chimeric mice. These chimeric mice showed high contributions of alpha 4-null cells in many tissues, including skeletal muscle, and muscles lacking any detectable (< 2%) alpha 4-positive cells did not reveal any gross morphological abnormalities. Furthermore, assays for in vitro myogenesis using either pure cultures of alpha 4-null myoblasts derived from the chimeras or alpha 4-null ES cells showed conclusively that alpha 4 integrins are not essential for muscle cell fusion and differentiation. Taking these results together, we conclude that alpha 4 integrins appear not to play essential roles in normal skeletal muscle development.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Roberta Codato ◽  
Martine Perichon ◽  
Arnaud Divol ◽  
Ella Fung ◽  
Athanassia Sotiropoulos ◽  
...  

AbstractThe coordinated expression of myogenic regulatory factors, including MyoD and myogenin, orchestrates the steps of skeletal muscle development, from myoblast proliferation and cell-cycle exit, to myoblast fusion and myotubes maturation. Yet, it remains unclear how key transcription factors and epigenetic enzymes cooperate to guide myogenic differentiation. Proteins of the SMYD (SET and MYND domain-containing) methyltransferase family participate in cardiac and skeletal myogenesis during development in zebrafish, Drosophila and mice. Here, we show that the mammalian SMYD3 methyltransferase coordinates skeletal muscle differentiation in vitro. Overexpression of SMYD3 in myoblasts promoted muscle differentiation and myoblasts fusion. Conversely, silencing of endogenous SMYD3 or its pharmacological inhibition impaired muscle differentiation. Genome-wide transcriptomic analysis of murine myoblasts, with silenced or overexpressed SMYD3, revealed that SMYD3 impacts skeletal muscle differentiation by targeting the key muscle regulatory factor myogenin. The role of SMYD3 in the regulation of skeletal muscle differentiation and myotube formation, partially via the myogenin transcriptional network, highlights the importance of methyltransferases in mammalian myogenesis.


2003 ◽  
Vol 55 (4) ◽  
pp. 278-278
Author(s):  
U. Cheema ◽  
S-Y. Yang ◽  
V. Mudera ◽  
G. Goldspink ◽  
R.A. Brown

1993 ◽  
Vol 122 (6) ◽  
pp. 1337-1350 ◽  
Author(s):  
MK Lee ◽  
Z Xu ◽  
PC Wong ◽  
DW Cleveland

Neurofilaments (NFs), composed of three distinct subunits NF-L, NF-M, and NF-H, are neuron-specific intermediate filaments present in most mature neurons. Using DNA transfection and mice expressing NF transgenes, we find that despite the ability of NF-L alone to assemble into short filaments in vitro NF-L cannot form filament arrays in vivo after expression either in cultured cells or in transgenic oligodendrocytes that otherwise do not contain a cytoplasmic intermediate filament (IF) array. Instead, NF-L aggregates into punctate or sheet like structures. Similar nonfilamentous structures are also formed when NF-M or NF-H is expressed alone. The competence of NF-L to assemble into filaments is fully restored by coexpression of NF-M or NF-H to a level approximately 10% of that of NF-L. Deletion of the head or tail domain of NF-M or substitution of the NF-H tail onto an NF-L subunit reveals that restoration of in vivo NF-L assembly competence requires an interaction provided by the NF-M or NF-H head domains. We conclude that, contrary to the expectation drawn from earlier in vitro assembly studies, NF-L is not sufficient to assemble an extended filament network in an in vivo context and that neurofilaments are obligate heteropolymers requiring NF-L and NF-M or NF-H.


Cytokine ◽  
2011 ◽  
Vol 55 (1) ◽  
pp. 104-109 ◽  
Author(s):  
Marissa K. Caldow ◽  
Gregory R. Steinberg ◽  
David Cameron-Smith

Sign in / Sign up

Export Citation Format

Share Document