Modification of expression of stem cell factor by various cytokines

The local production of stem cell factor (SCF) may be an important mechanis m for regulating proliferation, differentiation, and migration of various c ells bearing c-kit receptors, and might be susceptible to the cytokines tha t serve in inflammation and tissue repair. We have demonstrated that in thr ee murine cell lines, Balb/3T3A31, MC3T3-E1, and C3H-2K, which constitutive ly produced SCF with different quantity, the SCF mRNA expression was greatl y enhanced in response to basic fibroblast growth factor (bFGF) or transfor ming growth factor beta 1 (TCF-beta 1). The study was carried out by in sit u hybridization utilizing nonradioactive oligonucleotide probes and quantit ative image analysis. Leukemia inhibitory factor (LIF) or interleukin-4 (lL -4) moderately increased SCF mRNA in all cell lines, but IL-3 did not. The dot-blot enzyme-linked immunosorbent assay (ELISA) further confirmed that S CF protein production in these cell lines and bone marrow stromal cells was markedly enhanced by TGF-beta 1, although TGF-beta 1 suppressed the prolif eration of all these cells. bFGF also enhanced the SCF production in these cell lines, but did not in bone marrow stromal cells, suggesting a differen ce in their susceptibility to the cytokine. Our results suggest that TGF-be ta 1 and bFGF potentially modulate the biological function of cells bearing c-kit receptors through the modulation of SCF production in fibroblasts. ( C) 1999 Wiley-Liss, Inc.