title: beta-Endorphin as a regulator of human hair follicle melanocyte biology.
abstract: The pro-opiomelanocortin (POMC)-derived peptides, alpha-melanocyte-stimulating hormone, and adrenocorticotropic hormone, are important mediators of human skin pigmentation via action at the melanocortin-1 receptor. Recent data suggests that such a regulatory role also exists for the endogenous opiate, beta-endorphin (beta-END). A role for this beta-END in the regulation of follicular pigmentation, however, has not been determined. This study was designed to examine the involvement of the beta-END/mu-opiate receptor system in human follicular melanocyte biology. We employed RT-PCR, and immunohisto/cytochemistry and immunoelectron microscopy using beta-END and mu-opiate receptor specific antibodies and a functional role for beta-END was assessed by direct stimulation with the peptide. This study has demonstrated that human hair follicle melanocytes (HFM) express mRNA for the mu-opiate receptor and POMC. Furthermore, beta-END and its high affinity mu-opiate receptor are expressed at the protein level in glycoprotein100-positive follicular melanocytes and as a function of their anatomic location and differentiation status during the hair growth cycle. Functional studies revealed that beta-END is a modifier of HFM phenotype via its ability to upregulate melanogenesis, dendricity, and proliferation. These findings suggest a new regulatory role for beta-END in human HFM biology, providing a new research direction into the fundamental regulation of human hair pigmentation.
authors.affiliation: Department of Biomedical Sciences, University of Bradford, West Yorkshire, UK.
authors.forename: Söbia
authors.initials: S
authors.lastname: Kauser
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Thody
authors.forename: Karin U
authors.initials: KU
authors.lastname: Schallreuter
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Gummer
authors.forename: Desmond J
authors.initials: DJ
authors.lastname: Tobin
mesh_terms: D000328:Adult; D002455:Cell Division / Q000502:physiology; D048429:Cell Size / Q000502:physiology; D002478:Cells, Cultured; D005260:Female; D015870:Gene Expression / Q000502:physiology; D018859:Hair Follicle / Q000166:cytology / Q000254:growth & development / Q000502:physiology*; D006801:Humans; D008544:Melanocytes / Q000166:cytology / Q000502:physiology*; D020460:Melanosomes / Q000502:physiology; D008875:Middle Aged; D011333:Pro-Opiomelanocortin / Q000235:genetics / Q000378:metabolism; D011957:Receptors, Opioid / Q000235:genetics / Q000378:metabolism; D017450:Receptors, Opioid, mu / Q000235:genetics; D012880:Skin Pigmentation / Q000502:physiology*; D001615:beta-Endorphin / Q000502:physiology*
chemical_list: D011957:Receptors, Opioid; D017450:Receptors, Opioid, mu; D001615:beta-Endorphin; D011333:Pro-Opiomelanocortin