title: The effect of nutritional status on myogenic gene expression of satellite cells derived from different muscle types.
abstract: Satellite cells (SC) are a multipotential stem cell population responsible for facilitating posthatch muscle fiber hypertrophy. The proliferation and differentiation of SC is sensitive to nutritional regimen, and the SC response to nutrition varies depending upon their muscle type of origin. The objective of the current study was to determine the effect of altering protein synthesis on the expression of several key genes regulating SC activity and the effect of muscle type. Satellite cells isolated from the fast glycolytic pectoralis major and the fast oxidative and glycolytic biceps femoris were studied. These genes included the myogenic regulatory factors myogenic determination factor 1 (MyoD) and myogenin, the cell-membrane associated proteoglycans syndecan-4 and glypican-1, the extracellular matrix proteoglycan decorin, and the transcription factor paired box 7. Protein synthesis potential varied by the concentration of the sulfur amino acids Met and Cys during SC proliferation and differentiation. The SC were cultured and treated with 1 of 6 Met/Cys concentrations: 60/192, 30/96 (control), 7.5/24, 3.0/9.6, 1.0/3.2, or 0/0 mg/L. A consistent pattern of gene expression emerged following Met/Cys manipulation as increasing reductions in mRNA expression for all genes were observed as Met/Cys concentration decreased, whereas increased Met/Cys concentration caused either no change or had a small negative effect on mRNA expression. Reduced paired box 7 expression would limit myogenic specification of SC, whereas decreased myogenic regulatory factor expression would affect subsequent myogenic development of the SC. Decreased levels of decorin affect SC response to growth factors like myostatin and transforming growth factor β, and extracellular matrix organization. These data highlight the importance of nutrition on the expression of genes critical for satellite cell activation, proliferation and differentiation, and growth factor signal transduction.
authors.affiliation: Faculty of Veterinary Science, The University of Sydney, Camden, NSW 2750, Australia Poultry Cooperative Research Centre, PO Box U242, University of New England, Armidale, NSW 2351, Australia.
authors.forename: D J
authors.initials: DJ
authors.lastname: Powell
authors.affiliation: Department of Animal Science, South Dakota State University, Brookings 57007.
authors.forename: D C
authors.initials: DC
authors.lastname: McFarland
authors.affiliation: Faculty of Veterinary Science, The University of Sydney, Camden, NSW 2750, Australia.
authors.forename: A J
authors.initials: AJ
authors.lastname: Cowieson
authors.affiliation: Faculty of Veterinary Science, The University of Sydney, Camden, NSW 2750, Australia.
authors.forename: W I
authors.initials: WI
authors.lastname: Muir
authors.affiliation: Department of Animal Sciences, The Ohio State University/Ohio Agricultural Research and Development Center, Wooster 44691 velleman.1@osu.edu.
authors.forename: S G
authors.initials: SG
authors.lastname: Velleman
mesh_terms: D000818:Animals; D030161:Avian Proteins / Q000235:genetics* / Q000378:metabolism; D002645:Chickens / Q000235:genetics* / Q000378:metabolism; D003545:Cysteine / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D008715:Methionine / Q000378:metabolism; D018485:Muscle Fibers, Skeletal / Q000378:metabolism*; D009124:Muscle Proteins / Q000235:genetics* / Q000378:metabolism; D009752:Nutritional Status; D010369:Pectoralis Muscles / Q000166:cytology / Q000378:metabolism; D032496:Satellite Cells, Skeletal Muscle / Q000166:cytology / Q000378:metabolism*
chemical_list: D030161:Avian Proteins; D009124:Muscle Proteins; D008715:Methionine; D003545:Cysteine
keywords: Pax7; muscle satellite cell; myogenic regulatory factor; nutrition; proteoglycan