The chemotactic effect of a dermal papilla cell-derived factor on outer root sheath cells

The effect of cultured normal human dermal papilla cells (DPCs) and conditi oned medium prepared with cultured DPCs on chemotactic migration of human h air outer root sheath cells (ORSCs) was examined quantitatively. ORSCs show ed significantly increased migration toward both cultured DPCs and the cond itioned medium suggesting that DPCs produce and secrete a paracrine factor( s), which attracts hair follicle epithelial cells. Some soluble factors, wh ich are reportedly produced by DPCs, such as insulin-like growth factor-I ( IGF-I), hepatocyte growth factor (HGF), vascular endothelial cell growth fa ctor (VEGF), and transforming growth factor-beta1 (TGF-beta1), were also ex amined. ORSCs showed dramatically increased migration toward IGF-I and HGF at concentrations of 1-10 ng/ml. On the other hand, neither VEGF nor TGF-be ta1 showed any effect on the chemotaxis of ORSCs. It is interesting that al l factors involving mitogenic activity did not always have chemotactic acti vity for ORSCs. This is the first report to establish that IGF-I and HGF ha ve not only a growth stimulatory but also a chemotactic effect on ORSCs. In addition, the method presented here may help to simplify chemotaxis assays of any type of epithelial keratinocytes with poor mobility. (C) 2001 Elsev ier Science Ireland Ltd. All rights reserved.