Topobiology of Human Pigmentation: P-Cadherin Selectively Stimulates Hair Follicle Melanogenesis
TLDR P-cadherin is crucial for hair follicle pigmentation but not skin pigmentation.
The study investigated the role of P-cadherin in human hair follicle (HF) pigmentation. It was found that silencing P-cadherin in melanogenically active organ-cultured human scalp HFs significantly reduced HF melanogenesis, tyrosinase activity, and the expression of key pigmentation-related genes and proteins, such as gp100, stem cell factor, c-Kit, and MITF. This effect was specific to hair follicles, as epidermal pigmentation remained unaffected. The findings suggested that P-cadherin-GSK3β/Wnt signaling is crucial for maintaining MITF expression and sustaining intrafollicular melanogenesis, indicating that P-cadherin is a melanocyte subtype-specific regulator of normal human pigmentation.