RT Journal Article SR Electronic T1 VDR is an essential regulator of hair follicle regression through the progression of cell death JF Life Science Alliance JO Life Sci. Alliance FD Life Science Alliance LLC SP e202302014 DO 10.26508/lsa.202302014 VO 6 IS 11 A1 Joko, Yudai A1 Yamamoto, Yoko A1 Kato, Shigeaki A1 Takemoto, Tatsuya A1 Abe, Masahiro A1 Matsumoto, Toshio A1 Fukumoto, Seiji A1 Sawatsubashi, Shun YR 2023 UL http://www.life-science-alliance.org/content/6/11/e202302014.abstract AB Vitamin D receptor (VDR) is essential for hair follicle homeostasis as its deficiency induces hair loss, although the mechanism involved remains unknown. Our research shows that, in Vdr-knockout mice, the hair cycle is halted during the catagen stage, preceding alopecia. In addition, in Vdr-knockout hair follicles, epithelial strands that normally regress during the catagen phase persist as “surviving epithelial strands.” Single-cell RNA sequencing analysis suggests that these surviving epithelial strands are formed by cells in the lower part of the hair follicle. These findings emphasize the importance of the regression phase in hair follicle regeneration and establish VDR as a regulator of the catagen stage.