MyoD-deficient mice are without obvious deleterious muscle phenotype during embryogenesis and fetal development, and adults in the laboratory have grossly normal skeletal muscle and life span. However, a previous study showed that in the context of muscle degeneration on a mdx (dystrophin null) genetic background, animals lacking MyoD have a greatly intensified disease phenotype leading to leth...

The insulin-like growth factors (IGFs) play key roles in muscle development, maintenance, and repair, but their mechanisms of action are incompletely defined. We previously identified an autocrine pathway involving production of IGF-II and activation of the IGF-I receptor, phosphatidylinositol 3-kinase, and Akt in myoblast differentiation induced by MyoD in 10T1/2 mesenchymal stem cells and fou...

BACKGROUND Activation of hepatic stellate cells (HSCs) to a myofibroblastic phenotype is a key event in liver fibrosis. Identification of transcription factors with activities that are modulated during HSC activation will improve our understanding of the molecular events controlling HSC activation. AIMS To determine if changes in E-box DNA binding activity occur during in vitro and in vivo ac...

Cell-substratum interactions trigger key signaling pathways that modulate growth control and tissue-specific gene expression. We have previously shown that abolishing adhesive interactions by suspension culture results in G(0) arrest of myoblasts. We report that blocking intracellular transmission of adhesion-dependent signals in adherent cells mimics the absence of adhesive contacts. We invest...

To evaluate the biological functions of myogenic regulatory factors, we have examined the effects of ectopic expression of MyoD and Cx43 genes in the fibroblasts on the differentiation of myoblast in vitro. The expression of MyoD and Cx43 in the transfectants was confirmed by RT-PCR and Western blot. More than 50% of fibroblasts transfected with MyoD or both MyoD and Cx43 genes displayed typica...

The expression of the myogenic regulatory factors (MRFs), Myf5, MyoD, myogenin (Mgn) and MRF4 have been analysed during the development of chicken embryo somites and limbs. In somites, Myf5 is expressed first in somites and paraxial mesoderm at HH stage 9 followed by MyoD at HH stage 12, and Mgn and MRF4 at HH stage 14. In older somites, Myf5 and MyoD are also expressed in the ventrally extendi...

Muscle progenitors in Xenopus interact in a community of 100 or more cells to activate their myogenic genes and the muscle differentiation pathway. We examine whether the cell adhesion molecule cadherin is involved in this process. Injections of dominant negative N-cadherin RNA into the region of 2- to 4-cell embryos that will give rise to muscle suppress MyoD expression in muscle progenitor ce...

background: the purpose of present study was to investigate whether sphingosine 1-phosphate (s1p) levels and its receptors gene expressions are correlated with myod and myogenin following resistance training. materials and methods: 24 eight-week-old male wistar rats (190-250 gr) were assigned randomly to a control (n = 12) or training (n = 12) group. rats climbed a resistance training ladder wi...

PURPOSE To investigate the effectiveness of low-level laser therapy (LLLT) on gastrocnemius muscle morphology and Myod immunoexpression in a model of dorsal burn in rats. METHODS Sixteen male Wistar rats were distributed into two groups: control group (CG): rats submitted to scald burn injury without treatment and laser treated group (LG): rats submitted to scald burn injury and treated with ...

To understand how the skeletal muscle lineage is induced during vertebrate embryogenesis, we have sought to identify the regulatory molecules that mediate induction of the myogenic regulatory factors MyoD and Myf-5. In this work, we demonstrate that either signals from the overlying ectoderm or Wnt and Sonic hedgehog signals can induce somitic expression of the paired box transcription factors,...