FC-03   MACROPHAGE STIMULATING PROTEIN IS A POTENT PROMOTER OF ANAGEN STAGE HAIR FOLLICLES IN VITRO AND IN VIVO

KJ McElwee, S. Kissling, E. Wenzel, A. Huth, R. Hoffmann. Dept. Dermatology, Philipp University, Marburg, Germany.

Hepatocyte growth factor (HGF) has been identified as a promoter of hair follicle growth. We examined another HGF family member, macrophage stimulating protein (MSP), for its hair follicle modulating properties. Western blotting revealed expression of MSP in cultured human dermal papilla cells and bulbar dermal sheath cells, but not non bulbar dermal sheath cells. Immunohistology demonstrated expression of MSP receptor RON in most follicular structures including the outer and inner root sheaths, differentiating hair matrix cells, dermal papilla, bulbar dermal sheath and arrector pili muscle while non-follicular epithelium and some -24- cells of the sweat glands exhibited low level receptor expression. Human hair follicles from 5 donors (2 female, 3 male, mean age 27) exposed in vitro for 8 days to 0.1, 1, 10, and 100 ng/ml MSP yielded a mean net increase in hair follicle length of 10.3% (n=16, P=0.0023), 12.9% (n=30, P=0.0001), 9.8% (n=18, P=0.0008), and 8.4% (n=18, P=0.0072) respectively in excess of the 43.8% mean baseline growth observed in controls (n=36). MSP was incubated with agarose beads and injected subcutaneously into telogen skin of mice all 70 days old. All 8 mice receiving 1 µg MSP, and 4 of 8 receiving 100 ng MSP showed induction of anagen hair growth at the site of bead implantation by 16 days while 8 mice implanted with PBS incubated beads had no hair growth response. The data identify MSP as a modulator of hair follicle growth and suggest MSP can play a role in inducing anagen from telogen stage hair follicles.