Effects of platelet-derived growth factor and fibroblast growth factor on free intracellular calcium and mitogenesis

✍ Scribed by Robert W. Tucker; David T. Chang; Kimberly Meade-Cobun

• Publisher: John Wiley and Sons
• Year: 1989
• Tongue: English
• Weight: 763 KB
• Volume: 39
• Category: Article
• ISSN: 0730-2312
• DOI: 10.1002/jcb.240390206

✦ Synopsis

Although increased free intracellular calcium (Cai) may be one of the main regulators of cell growth and differentiation, studies in cell populations have implied that not all growth factors produce C q increases. In order to examine in more detail whether C q increases were related to mitogenesis, we used digital image analysis of intracellular Fura-2 fluorescence to measure C q in individual BALB/c 3T3 cells stimulated with either platelet-derived growth factor (PDGF) or fibroblast growth factor (FGF). We found that PDGF induced larger and more prolonged C q increases than FGF did, but that both growth factors induced an initial rapid increase in Cai ( < 2 min) followed by a later sustained increase (> 20 min). Only the prolonged Cai increase required extracellular calcium. Following PDGF treatment (1-8 units/ml), the percentage of cells with a large peak C q increase (>twofold) correlated with the percentage of cells made competent (subsequent growth in 1 % platelet-poor-plasma). In contrast, purified bovine basic FGF (200-800 pg/ml) and recombinant human acidic FGF (10-300 ng/ml) produced peak Cai increases that were not directly correlated with mitogenesis. In addition, concentrations of intracellular Quin 2 that inhibited Cai transients also inhibited PDGF stimulation but not FGF stimulation of mitogenesis. Thus, C q increases are necessary for mitogenesis in BALBlc 3T3 cells stimulated by PDGF, but not that stimulated by FGF.