Regulation of human hair follicle growth by neurokinin-1 receptor ligands

• Published in: Experimental dermatology Vol. 13; no. 9; pp. 583 - 584
• Main Authors: Lachgar, S., Metenier, S., Quibeuf, S., Charveron, M.
• Format: Journal Article
• Language: English
• Published: Oxford, UK; Malden, USA Blackwell Publishing Ltd/Inc 01.09.2004
• ISSN: 0906-6705; 1600-0625
• DOI: 10.1111/j.0906-6705.2004.0212bm.x

Recent reports revealed that neural mechanisms play a role in hair growth control. An induction of murine hair growth is obtained after treatment with substance P (SP). In this study, we examined the expression of a SP receptor: the neurokinin‐1 (NK1‐R) during: 1) the human hair cycle, 2) on isolated hair follicle, and 3) in cultured hair dermal papilla (HDPC) and the impact of NK1‐R ligands on the regulation of hair growth. We used immunohistochemistry, Western blot and RT‐PCR analysis to examine its expression. Anagen hair follicles showed a strong expression of NK1‐R in dermal papilla and in the outer root sheath. Weak expression of NK1‐R was observed in hair follicle at the catagen and telogen stages. Two isoforms of NK1‐R protein corresponding to 44 kDa and 54 kDa were identified in cultured HDPC. A fragment of 640 bp corresponding to NK1‐R was obtained by RT‐PCR. The nested PCR showed the expected band of NK1‐R at 395 bp. HDPC treatment with SP increases the level of NK1‐R gene and protein. The increase is stronger with NK1‐R‐selective agonist [Sar9, Met (O2) 11]‐SP. Ex vivo studies showed a significant dose‐dependent stimulation of hair growth by SP and by NK1‐R agonist. However, the NK1‐R antagonist (L‐732–138). showed a significant inhibition of hair follicle growth. These results demonstrate the presence of NK1‐R in the growing human hair follicle. NK1‐R is activated by SP and NK1‐R agonist. Ex vivo studies indicate that NK1‐R antagonist inhibited hair follicle growth.