The biology and molecular regulation of MeSCs in hair follicles and their therapeutic potential for hypopigmentation disorders

Melanocytes, which produce melanin, a natural pigment, arise from the neural crest during embryonic development. They reside primarily in the epidermis and hair follicles, where they are responsible for generating diverse skin tones to shield against UV radiation and for hair pigmentation. Melanocyte stem cells (MeSCs), located in the bulge/sub-bulge region of hair follicles, are essential for regenerating mature melanocytes. Disruptions in the MeSCs population within their microenvironment can impair melanocyte lineage, leading to pigmentation disorders like vitiligo and canities. Essentially, the production of melanin relies on the proliferation and differentiation of MeSCs. This review aims to investigate the intricate signaling networks regulating MeSCs differentiation and hair pigmentation. By delving into these networks, we can enhance our comprehension of hypopigmentation disorders and improve the application of regenerative medicine in clinical settings.