TY - JOUR
T1 - Activation of Skeletal Muscle Satellite Cells and the Role of Fibroblast Growth Factor Receptors
AU - Johnson, Sally E.
AU - Allen, Ronald E.
PY - 1995/8
Y1 - 1995/8
N2 - Specific, high-affinity binding of FGF2 was evaluated in cultured skeletal muscle satellite cells from young (3- to 4-week-old) and adult (9- to 12-month-old) rats prior to the first division in culture. Specific binding of FGF2 was detected on satellite cells from young rats at 18 h postplating, the earliest time examined, but specific binding was not detectable until 42 h on satellite cells from old rats. This correlates well with the delayed entry into the cell cycle exhibited by adult satellite cells and with the ability of satellite cells from rats of these ages to proliferate in response to FGF2. Patterns of tyrosine phosphorylation in whole cell extracts, following stimulation by FGF2, indicated specific FGF2 phosphorylation of proteins of 150/145, 90, 42, and 35 kDa in cells from both age groups. Several growth factors were evaluated for their ability to stimulate early entry of adult satellite cells into the cell cycle, and none of the following growth factors were able to activate proliferation of these cells: FGF2, IGF-1, IGF-2, PDGF-BB, TGF-β1, or TGF-β2. In addition, specific binding of FGF2 to 48-h cultures of adult satellite cells was not stimulated by FGF2, IGF-1, IGF-2, PDGF-BB, or TGF-β2, and specific binding was significantly decreased (P < 0.05) by FGF2 and TGF-β2. Specific binding was significantly lower in cells treated with PDGF-BB than in cells treated with either form of IGF but was greater than in cells treated with FGF2 or TGF-β2. The results of these experiments suggest that expression of functional FGF receptors on the surface of satellite cells may represent an important step in the activation of quiescent satellite cells.
AB - Specific, high-affinity binding of FGF2 was evaluated in cultured skeletal muscle satellite cells from young (3- to 4-week-old) and adult (9- to 12-month-old) rats prior to the first division in culture. Specific binding of FGF2 was detected on satellite cells from young rats at 18 h postplating, the earliest time examined, but specific binding was not detectable until 42 h on satellite cells from old rats. This correlates well with the delayed entry into the cell cycle exhibited by adult satellite cells and with the ability of satellite cells from rats of these ages to proliferate in response to FGF2. Patterns of tyrosine phosphorylation in whole cell extracts, following stimulation by FGF2, indicated specific FGF2 phosphorylation of proteins of 150/145, 90, 42, and 35 kDa in cells from both age groups. Several growth factors were evaluated for their ability to stimulate early entry of adult satellite cells into the cell cycle, and none of the following growth factors were able to activate proliferation of these cells: FGF2, IGF-1, IGF-2, PDGF-BB, TGF-β1, or TGF-β2. In addition, specific binding of FGF2 to 48-h cultures of adult satellite cells was not stimulated by FGF2, IGF-1, IGF-2, PDGF-BB, or TGF-β2, and specific binding was significantly decreased (P < 0.05) by FGF2 and TGF-β2. Specific binding was significantly lower in cells treated with PDGF-BB than in cells treated with either form of IGF but was greater than in cells treated with FGF2 or TGF-β2. The results of these experiments suggest that expression of functional FGF receptors on the surface of satellite cells may represent an important step in the activation of quiescent satellite cells.
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U2 - 10.1006/excr.1995.1251
DO - 10.1006/excr.1995.1251
M3 - Article
C2 - 7641796
AN - SCOPUS:0029087215
VL - 219
SP - 449
EP - 453
JO - Experimental Cell Research
JF - Experimental Cell Research
SN - 0014-4827
IS - 2
ER -