title: The TRPM8 protein is a testosterone receptor: I. Biochemical evidence for direct TRPM8-testosterone interactions.
abstract: The transient receptor potential ion channel of the melastatin subfamily, TRPM8, is a major cold receptor in the peripheral nervous system. Along with the sensory neurons, the TRPM8 protein is highly expressed in the prostate epithelial cells, and this expression is regulated by androgens. Here we investigated the expression and intracellular localization of the TRPM8 channel in relationship to androgens. We performed experiments using human prostate tissues obtained from healthy individuals and patients with prostate cancer at various stages of the disease as well as in cultured cells. Using an immunohistochemistry approach, we detected an intensive colocalization pattern of the TRPM8 protein with endogenous androgens in all tissues tested, suggesting possible interactions. Co-immunoprecipitation experiments performed using cultured prostate epithelial cells, prostate cancer cells, and HEK-293 cells stably expressing TRPM8 further confirmed direct binding of the steroid hormone, testosterone, to the TRPM8 protein. Applications of picomolar concentrations of testosterone to the primary human prostate cells, endogenously expressing TRPM8, elicited Ca(2+) responses and channel currents, and those were inhibited in the presence of TRPM8 antagonist, N-(2-aminoethyl)-N-(4-(benzyloxy)-3-methoxybenzyl)thiophene-2-carboxamide hydrochloride. These results indicate that the TRPM8 channel is physically associated with testosterone and suggest that, in addition to a genomic role, testosterone plays a role in direct regulation of the TRPM8 channel function.
authors.affiliation: From the Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine, Peoria, Illinois 61605.
authors.forename: Swapna
authors.initials: S
authors.lastname: Asuthkar
authors.affiliation: Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada.
authors.forename: Pia A
authors.initials: PA
authors.lastname: Elustondo
authors.affiliation: From the Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine, Peoria, Illinois 61605.
authors.forename: Lusine
authors.initials: L
authors.lastname: Demirkhanyan
authors.affiliation: From the Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine, Peoria, Illinois 61605.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Sun
authors.affiliation: the College of Health Sciences, School of Pharmacy, University of Wyoming, Laramie, Wyoming 82071, and.
authors.forename: Padmamalini
authors.initials: P
authors.lastname: Baskaran
authors.affiliation: From the Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine, Peoria, Illinois 61605.
authors.forename: Kiran Kumar
authors.initials: KK
authors.lastname: Velpula
authors.affiliation: the College of Health Sciences, School of Pharmacy, University of Wyoming, Laramie, Wyoming 82071, and.
authors.forename: Baskaran
authors.initials: B
authors.lastname: Thyagarajan
authors.affiliation: Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada, the Department of Basic Sciences, College of Dentistry, New York University, New York, New York 10010.
authors.forename: Evgeny V
authors.initials: EV
authors.lastname: Pavlov
authors.affiliation: From the Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine, Peoria, Illinois 61605, zakharel@uic.edu.
authors.forename: Eleonora
authors.initials: E
authors.lastname: Zakharian
mesh_terms: D002460:Cell Line; D045744:Cell Line, Tumor; D004797:Enzyme-Linked Immunosorbent Assay; D057809:HEK293 Cells; D006801:Humans; D007150:Immunohistochemistry; D047468:Immunoprecipitation; D008297:Male; D011485:Protein Binding; D011944:Receptors, Androgen / Q000378:metabolism*; D050053:TRPM Cation Channels / Q000378:metabolism*; D013739:Testosterone / Q000378:metabolism*
chemical_list: D011944:Receptors, Androgen; D050053:TRPM Cation Channels; C425966:TRPM8 protein, human; D013739:Testosterone
keywords: Androgen; Calcium Channel; Cold and Menthol Receptor TRPM8; Ion Channel; Testosterone; Transient Receptor Potential Channels (TRP Channels); Transient Receptor Potential Melastatin 8 Channel