Dermal Blimp1 acts downstream of epidermal TGFβ and Wnt/β-catenin to regulate hair follicle formation and growth.

J Invest Dermatol. 2017 Jun 28. pii: S0022-202X(17)31773-6. doi: 10.1016/j.jid.2017.06.015. [Epub ahead of print]
Dermal Blimp1 acts downstream of epidermal TGFβ and Wnt/β-catenin to regulate hair follicle formation and growth.

Telerman SB1, Rognoni E1, Sequeira I1, Pisco AO1, Lichtenberger BM2, Culley O1, Viswanathan P1, Driskell RR1, Watt FM3.

Blimp1 is a transcriptional repressor that regulates cell growth and differentiation in multiple tissues, including skin. While in the epidermis Blimp1 is important for keratinocyte and sebocyte differentiation, its role in dermal fibroblast is unclear. Here we show that Blimp1 is dynamically regulated in dermal papilla (DP) cells during hair follicle (HF) morphogenesis and the postnatal hair cycle, preceding dermal Wnt/β-catenin activation. Blimp1 ablation in E12.5 mouse dermal fibroblasts delayed HF morphogenesis and growth and prevented new HF formation following wounding. By combining targeted qPCR screens with bioinformatic analysis and experimental validation we demonstrated that Blimp1 is both a target and mediator of key DP inductive signalling pathways including TGFβ and Wnt/β-catenin. Epidermal overexpression of stabilised β-catenin was able to override the HF defects in Blimp1 mutant mice, underlining the close reciprocal relationship between the DP and adjacent HF epithelial cells. Overall, our study reveals the functional role of Blimp1 in promoting the DP inductive signalling cascade that initiates HF growth.

What can be done to maintain or promote Blimp1?