Androgen Induction of Follicular Epithelial Cell Growth Is Mediated via Insulin-like Growth Factor-I from Dermal Papilla Cells

In the study from July 1, 1995, it was found that androgen significantly promotes the growth of outer root sheath cells when they are cocultured with beard dermal papilla cells, even without direct cell contact. The beard dermal papilla cells showed increased expression of insulin-like growth factor I (IGF-I) mRNA when exposed to androgen, a response that was inhibited by the anti-androgenic drug cyproterone acetate. The outer root sheath cells did not show any expression of IGF-I mRNA, regardless of androgen presence. Both cell types expressed mRNA for the IGF-I receptor, and this expression was not altered by androgen. The use of a neutralizing antibody against IGF-I reduced the androgen's growth-stimulating effects on the outer root sheath cells in coculture with beard dermal papilla cells. These results indicate that IGF-I may be a mediator for androgen-induced hair growth. The specific number of people or cells used in the study was not mentioned in the summary provided.