Myosin heavy chain mRNA isoforms are expressed in two distinct cohorts during C2C12 myogenesis

Abstract

The regulation of muscle fibre transitions has mainly been studied in vivo using conventional histological or immunohistochemical techniques. In order to investigate the molecular regulation of myosin heavy chain (MyHC) isoform expression in cell culture studies, we first characterised the normal transitions in endogenous expression of the MyHC isoforms and the myogenic regulatory factors during differentiation of C2C12 muscle cells. Interestingly, across the time course of differentiation, MyHC mRNA isoforms were expressed in a distinct temporal pattern as two distinct cohorts, one including MyHC I, embryonic and neonatal, the other including MyHC IIa, IIx and IIb. The pattern of expression suggests a transition in MyHC isoforms, from one cohort to another, occurs during muscle cell differentiation and that these transitions occur independent of nerve innervation. To our knowledge, this is the most comprehensive analysis of in vitro MyHC mRNA isoform transitions and provides important information for studying the regulation of transitions in MyHC isoforms in cell culture systems.

G-CSF does not influence C2C12 myogenesis despite receptor expression in healthy and dystrophic skeletal muscle

“…C2C12 cells formed visible myotubes after 4 days (Figure 2A), with differentiation confirmed by measuring various myosin heavy chain ( Myh7, 4, 2, 1 ) mRNA levels, known markers of muscle cell differentiation (Brown et al, 2012). All Myh mRNAs were elevated by day 3 ( p < 0.01) and day 4 ( p < 0.001) when compared to day 0 (Figure 2B).…”

“…They also did not clearly describe if proliferation was measured in the presence or absence of serum, nor was the level of cell confluence at the time of treatment with G-CSF stated (Hara et al, 2011), making their results difficult to interpret. Myosin heavy chain proteins regulate skeletal muscle contraction and their mRNA levels are significantly increased during myogenesis (Brown et al, 2012). In the current study mRNA expression levels for myosin heavy chains ( Myh -7, - 4 , - 2 and - 1 ) continued to increase throughout differentiation.…”

Low Glucose but Not Galactose Enhances Oxidative Mitochondrial Metabolism in C2C12 Myoblasts and Myotubes

“…The differentiation process is associated with the expression of differentiation markers such as myosin heavy chain (MHC), which is considered a typical marker for terminally differentiated muscle cells [14]. Glucose starvation is known to impair the differentiation process [15], [16], therefore we investigated whether galactose can be substituted for glucose.…”

JAZF1 promotes proliferation of C2C12 cells, but retards their myogenic differentiation through transcriptional repression of MEF2C and MRF4—Implications for the role of Jazf1 variants in oncogenesis and type 2 diabetes

“…The expression level of MyoD in JAZF1-OE or JAZF1-DR cells was very similar to that in each control cells. These results indicated that JAZF1 expression preferentially affected the myogenic genes expressed later during myogenic differentiation and in adult skeletal muscle, such as Mrf4, Mef2c, Myh1, and Ckm [18][19][20][21][22].…”