Corticotropin releasing hormone stimulates proliferation of keratinocytes

Corticotropin releasing hormone (CRH) is a potent mediator of stress respon ses and stress-induced disorders. Consistent with the broad range of roles proposed for CRH, high-affinity binding sites have been found in various pe ripheral sites. Recently two types of CRH specific receptor have been ident ified. Expression of CRH receptor 1 (CRH-R1) gene has been detected in huma n keratinocyte, but the effects of CRH to keratinocytes are still unknown. We tested whether CRH induced keratinocyte proliferation via interaction wi th CRH R1. Expression of CRH-R1mRNA in the human keratinocyte and HSC-2, ke ratinocyte cell line, was analyzed by RT-PCR. The human keratinocyte and HS C-2 were recognized to have CRH-R1 expression ability. CRH signal is transd uced into a cAMP-activated metabolic pathway via interaction with CRH-R1. R adioimmunoassay indicated that CRH binds to CRH receptor in HSC-2 cell when activating the metabolic pathway. Using thymidine incorporation assay, CRH had proliferative effect to HSC-2. This study suggests that CRH induces th e proliferation of keratinocytes via interation with CRH receptors. (C) 200 1 Elsevier Science Inc. All rights reserved.