Identifying novel strategies for treating human hair loss disorders: Cyclosporine A suppresses the Wnt inhibitor, SFRP1, in the dermal papilla of human scalp hair follicles

by Nathan J. Hawkshaw, Jonathan A. Hardman, Iain S. Haslam, Asim Shahmalak, Amos Gilhar, Xinhong Lim, Ralf Paus Hair growth disorders often carry a major psychological burden. Therefore, more effective human hair growth–modulatory agents urgently need to be developed. Here, we used the hypertrichosis-inducing immunosuppressant, Cyclosporine A (CsA), as a lead compound to identify new hair growth–promoti ng molecular targets. Through microarray analysis we identified the Wnt inhibitor, secreted frizzled related protein 1 (SFRP1), as being down-regulated in the dermal papilla (DP) of CsA-treated human scalp hair follicles (HFs) ex vivo. Therefore, we further investigated the function of SFRP1 using a pharmacological approach and found that SFRP1 regulates intrafollicular canonical Wnt/β-catenin activity through inhibition of Wnt ligands in the human hair bulb. Conversely, inhibiting SFRP1 activity through the SFRP1 antagonist, WAY-316606, enhanced hair shaft production, hair shaft keratin expr ession, and inhibited spontaneous HF regression (catagen) ex vivo. Collectively, these data (a) identify Wnt signalling as a novel, non–immune-inhibitory CsA target; (b) introduce SFRP1 as a physiologically important regulator of canonical β-catenin activity in a human (mini-)organ; and (c) demon strate WAY-316606 to be a promising new promoter of human hair growth. Since inhibiting SFRP1 only facilitates Wnt signalling through ligands that are already present, this ‘ligand-lim...
Source: PLoS Biology: Archived Table of Contents - Category: Biology Authors: Source Type: research