Myogenin, as well as other MyoD-related skeletal muscle-specific transcription factors, regulate a large number of skeletal muscle genes during myogenic differentiation. During later development, innervation suppresses myogenin expression in the fetal hind limb musculature. Denervation of skeletal muscle reverses the effects of the nerve, and results in the reactivation of myogenin expression, ...

BACKGROUND α-Syntrophin is a scaffolding protein linking signaling proteins to the sarcolemmal dystrophin complex in mature muscle. However, α-syntrophin is also expressed in differentiating myoblasts during the early stages of muscle differentiation. In this study, we examined the relationship between the expression of α-syntrophin and myogenin, a key muscle regulatory factor. METHODS AND FI...

[Purpose] We reported that carbon dioxide (CO2) water bathing accelerates skeletal muscle regeneration; however, the underlying mechanism was unclear. MyoD and myogenin play roles in muscle regeneration, and the purpose of this study was to determine changes in MyoD and myogenin caused by CO2 water bathing after injury. [Subjects] Sixteen female Wistar rats (n = 4 per group) were used. [Methods...

Satellite cell proliferation was assessed in low-frequency-stimulated hypothyroid rat fast-twitch muscle by 5-bromo-2'-deoxyuridine (BrdU) labeling and subsequent staining of labeled muscle nuclei, and by staining for proliferating cell nuclear antigen (PCNA). BrdU labeling and PCNA staining were highly correlated and increased approximately fourfold at 5 days of stimulation, decayed thereafter...

Doxorubicin, an anthracycline antibiotic, has been used as an anti-neoplastic drug for almost 60 years. However, the mechanism(s) by which anthracyclines cause irreversible myocardial injury remains unclear. In order to delineate possible molecular signals involved in the myocardial toxicity, we assessed candidate genes using mRNA expression profiling in the doxorubicin-treated rat cardiomyocyt...

Myogenin is required not for the initiation of myogenesis but instead for skeletal muscle formation through poorly understood mechanisms. We demonstrate in cultured cells and, for the first time, in embryonic tissue, that myogenic late genes that specify the skeletal muscle phenotype are bound by MyoD prior to the initiation of gene expression. At the onset of muscle specification, a transition...

To investigate the role of myogenin in regulating acetylcholine receptor expression in adult muscle, this muscle-specific basic helix-loop-helix transcription factor was overexpressed in transgenic mice by using regulatory elements conferring strong expression confined to differentiated postmitotic muscle fibers. Many of the transgenic mice died during the first postnatal week, but those that s...

Alveolar rhabdomyosarcoma (RMS) has a much poorer outcome than embryonal RMS. In this study, we found that IGF-I affected the induction of myogenin and cell cycle progression in alveolar RMS cells, but not in embryonal RMS cells. IGF-I enhanced the induction of myogenin protein in alveolar RMS SJ-Rh30 and KP-RMS-MS cells as it did in myoblast C2C12 cells, but not in embryonal RMS RD or KP-RMS-K...

Activated Raf is a potent inhibitor of skeletal muscle gene transcription and myocyte formation through stimulation of downstream MAPK. However, the molecular targets of elevated MAPK with regard to myogenic repression remain elusive. We examined the effects of activated Raf on myogenin gene expression in avian myoblasts. Overexpression of activated Raf in embryonic chick myoblasts prevented my...

Myogenin and MyoD belong to a family of muscle-specific helix-loop-helix (HLH) proteins that have the potential to activate muscle-specific genes in nonmyogenic cells. Peptide growth factors can block the ability of myogenin and MyoD to activate their target genes. Here, we show that the growth factor-inducible proto-oncogenes c-fos, c-jun, and junB mimic the effects of exogenous growth factors...