Interferon β Secreted from Human Hair Dermal Papilla Cells Inhibits the Growth of Outer Root Sheath Cells Cultured in Vitro

Abstract

Hair growth is tightly regulated by the epithelial–mesenchymal interaction of hair follicle cells. To investigate the molecular interaction between epithelial and mesenchymal cells of the hair follicle, the outer root sheath (ORS) cells were cultured with the dermal papilla (DP)-conditioned medium. Using the techniques of differential display reverse transcription–polymerase chain reaction (DD RT–PCR) and Northern blot analysis, we identified that an interferon-inducible gene 6–16 is regulated in the ORS cells when cultured with the DP-conditioned medium. We further studied the effect of the DP-conditioned medium and found that interferon β, a predominant interferon secreted by the fibroblasts, is expressed by the DP cells. Moreover, the anti-interferon β neutralized DP-conditioned medium dramatically inhibited the 6–16 mRNA expression. Interferon β or DP-conditioned medium suppressed the growth of the in vitro cultured ORS cells, suggesting that interferon β secreted from the DP cells negatively regulates the growth of ORS cells. Together these results reveal the potential importance of the interferon β as a negative regulator of hair growth.