Keratinocytes Regulate the Function of Melanocytes

The document discussed how keratinocytes, which form the bulk of the epithelium and undergo keratinization, regulate the function of melanocytes located in the basal layer of the epidermis. Melanocytes produce melanin pigments that are transferred to keratinocytes. The interaction between keratinocytes and melanocytes, along with dermal fibroblasts, is crucial for the formation and homeostasis of hair follicles. Keratinocytes stimulate melanocyte functions such as proliferation, differentiation, and melanogenesis through paracrine factors like hormones, growth factors, and cytokines. These factors play a key role in maintaining epidermal and hair follicle homeostasis via receptor-mediated signaling pathways.