Expression data from human hair follicles (ex vivo) incubated with cyclosporine A and vehicle control

Since hair growth disorders can carry a major psychological burden, more effective human hair growth-modulatory agents need to be urgently developed. Here, we used the hypertrichosis-inducing immunosuppressant, cyclosporine A (CsA), as a lead compound to identify new hair growth-promoting targets. Through microarray analysis we identified the Wnt inhibitor, SFRP1, as being downregulated 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 expression and inhibited spontaneous HF regression (catagen) ex vivo. Collectively, these data (a) identify Wnt signaling 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) demonstrate WAY-316606 to be a promising new promoter of human hair growth. Since inhibiting SFRP1 only facilitates Wnt signaling through ligands that are already present, this “ligand-limited” therapeutic strategy for promoting human hair growth may circumvent potential oncological risks associated with chronic Wnt over-activation. We used microarrays to identify novel hair growth promoting targets in human hair follicles through the use of cyclosporine A. Human hair follicles were treated for 6 hours with cyclosporine A (10-7M) to identify primary changes in gene transcription and total RNA was extracted using RNAeasy mini kit. Subsequently RNA was prepared for the Affymetrix U133 plus 2.0 genechip. Matched patient samples were treated with either vehicle control or cyclosporine A (from three independent male samples).