title: Differentiation-dependent regulation of skeletal myogenesis by neuregulin-1.
abstract: Neuregulins comprise a group of growth factor proteins that regulate the differentiation of skeletal muscle. Here, we report that neuregulins are regulators of myogenic differentiation and stimulate mitogenesis in L6 skeletal myoblasts. The mitogenic response to neuregulin-1 was differentiation-dependent and observed only in aligned, differentiating cells. Treatment of these cells with neuregulin-1 increased [3H]thymidine incorporation and cell proliferation by 2- to 5-fold, while a minimal increase was seen in proliferating myoblasts. Neuregulin-1 did not induce DNA synthesis in fused, multinucleated myotubes. The increased DNA synthesis correlated with downregulation of myogenin and inhibition of myoblast fusion and myotube formation. These data suggest that neuregulins may regulate skeletal myogenesis in vivo and that this regulation is dependent on the state of differentiation of the myocytes.
authors.affiliation: Department of Anatomy and Neurobiology, Morehouse School of Medicine, 720 Westview Drive, SW, Atlanta, GA 30310, USA. BFord@msm.edu
authors.forename: Byron D
authors.initials: BD
authors.lastname: Ford
authors.forename: Bomie
authors.initials: B
authors.lastname: Han
authors.forename: Gerald D
authors.initials: GD
authors.lastname: Fischbach
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D004247:DNA / Q000096:biosynthesis; D018482:Muscle, Skeletal / Q000166:cytology / Q000187:drug effects* / Q000254:growth & development* / Q000378:metabolism; D032446:Myoblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D020890:Neuregulin-1 / Q000494:pharmacology* / Q000502:physiology; D010446:Peptide Fragments / Q000494:pharmacology; D051381:Rats
chemical_list: D020890:Neuregulin-1; D010446:Peptide Fragments; D004247:DNA