Dermal papilla cells express hepatocyte growth factor.

In the induction, development and maintenance of hair follicles, it is thought that an epithelial-mesenchymal interaction is important and that the dermal papilla plays some important roles. Hepatocyte growth factor is a multifunctional polypeptide which acts as mitogen, motogen or morphogen depending on the biological context. Recently, we found that HGF stimulates hair follicle growth in a mouse organ culture system, and therefore proceeded to investigate the expression of HGF on cultured human dermal papilla cells (DPC) and the effect of HGF on cultured human keratinocytes derived from hair bulb. Using an enzyme immuno assay, HGF immunoreactivities were not detected in conditioned media of DPC that were either non-treated or treated with TGF-beta, but were detected in conditioned media of DPC treated with IL1-alpha, TNF-alpha and TPA. Using the reverse transcription-polymerase chain reaction (RT-PCR) method, HGF mRNA was also detected in DPC. This expression was enhanced by IL1-alpha, TNF-alpha and TPA, but suppressed by TGF-beta. Furthermore, HGF stimulated the DNA synthesis in keratinocytes derived from human hair bulb in a dose-dependent manner. These results indicate that DPC express HGF in vitro and that HGF stimulates the growth of human keratinocytes derived from hair bulb in vitro.