Hair Graying Regulators Beyond Hair Follicle.

Jing Chen,Xuexiao Jin,Ying Xiao,Yixin Zheng,Chen Hu,Chaochen Wang,Xiaoping Chen

doi:10.3389/fphys.2022.839859

Abstract

Hair graying is an interesting physiological alteration associated with aging and certain diseases. The occurrence is due to depigmentation of the hair caused by depletion and dysfunction of melanocyte stem cells (MeSCs). However, what causes the depletion and dysfunction of MeSCs remains unclear. MeSCs reside in the hair follicle bulge which provides the appropriate niche for the homeostasis of various stem cells within hair follicle including MeSCs. In addition to local signaling from the cells composed of hair follicle, emerging evidences have shown that nerves, adipocytes and immune cells outside of hair follicle per se also play important roles in the regulation of MeSCs. Here, we review the recent studies on different cells in the MeSCs microenvironment beyond the hair follicle per se, discuss their function in regulating hair graying and potentially novel treatments of hair graying.

Highlights

Hair graying is one of the representative signs of aging
In addition to the cell types mentioned above, fibroblasts and microvessels make up a large portion of skin enwrapping hair follicles, which have been reported to greatly affect the pigmentation of epidermis
Fibroblasts secret a diversity of factors participate in modulating melanogenesis: KITL and KGF induce the proliferation and survival of melanocytes by MAPK signaling pathway, DKK1 and SFRP modulate pigmentation via WNT/β-catenin pathway (Wang et al, 2017)

Summary

Hair Graying Regulators Beyond Hair Follicle

Jing Chen 1,2, Yixin Zheng 2, Chen Hu 3, Xuexiao Jin 4, Xiaoping Chen 4, Ying Xiao 5* and Chaochen Wang 1,2*. Reviewed by: Mingxing Lei, Chongqing University, China Tiechi Lei, Renmin Hospital of Wuhan University, China. The occurrence is due to depigmentation of the hair caused by depletion and dysfunction of melanocyte stem cells (MeSCs). What causes the depletion and dysfunction of MeSCs remains unclear. MeSCs reside in the hair follicle bulge which provides the appropriate niche for the homeostasis of various stem cells within hair follicle including MeSCs. In addition to local signaling from the cells composed of hair follicle, emerging evidences have shown that nerves, adipocytes and immune cells outside of hair follicle per se play important roles in the regulation of MeSCs. Here, we review the recent studies on different cells in the MeSCs microenvironment beyond the hair follicle per se, discuss their function in regulating hair graying and potentially novel treatments of hair graying

INTRODUCTION

Microenvironment in Hair Graying

NEURAL MICROENVIRONMENT

IMMUNE CELLS

CONCLUSION AND PERSPECTIVES