Dermal Adipose Tissue Secretes HGF to Promote Human Hair Growth and Pigmentation.

Hair follicles (HFs) are immersed within dermal white adipose tissue (dWAT), yet human adipocyte‒HF communication remains unexplored. Therefore, we investigated how perifollicular adipocytes affect the physiology of human anagen scalp HFs. Quantitative immunohistomorphometry, X-ray microcomputed tomography, and transmission electron microscopy showed that the number and size of perifollicular adipocytes declined during anagen‒catagen transition, whereas fluorescence-lifetime imaging revealed increased lipid oxidation in adipocytes surrounding the bulge and/or sub-bulge region.

Inhibition of Shh Signaling through MAPK Activation Controls Chemotherapy-Induced Alopecia.

Chemotherapy-induced hair loss (alopecia) (CIA) remains a major unsolved problem in clinical oncology. CIA is often considered to be a consequence of the antimitotic and apoptosis-promoting properties of chemotherapy drugs acting on rapidly proliferating hair matrix keratinocytes. Here, we show that in a mouse model of CIA, the downregulation of Shh signaling in the hair matrix is a critical early event.