Participation of keratinocyte‐ and fibroblast‐derived factors in melanocyte homeostasis, the response to UV, and pigmentary disorders

• Published in: Pigment cell and melanoma research Vol. 34; no. 4; pp. 762 - 776
• Main Authors: Upadhyay, Parth R., Ho, Tina, Abdel‐Malek, Zalfa A.
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01.07.2021
• Subjects: Animals; Disorders; DNA damage response; Epidermis; Fibroblasts; Fibroblasts - metabolism; Fibroblasts - radiation effects; Genomics; Homeostasis; Homeostasis - radiation effects; Humans; Inflammation; Keratinocytes; Keratinocytes - metabolism; Keratinocytes - radiation effects; Melanin; Melanocytes; Melanocytes - metabolism; Melanocytes - radiation effects; paracrine factors; Paracrine signalling; Pathogenesis; pigmentary disorders; Pigmentation Disorders - pathology; Radiation; Radiation damage; Skin; Solar radiation; solar UV; Stability; Survival; Synthesis; Toxins; Ultraviolet radiation; Ultraviolet Rays; solar UV; melanocytes; pigmentary disorders; DNA damage response; paracrine factors
• ISSN: 1755-1471; 1755-148X; 1755-148X
• DOI: 10.1111/pcmr.12985

Human epidermal melanocytes play a central role in sensing the environment and protecting the skin from the drastic effects of solar ultraviolet radiation and other environmental toxins or inflammatory agents. Melanocytes survive in the epidermis for decades, which subjects them to chronic environmental insults. Melanocytes have a poor self‐renewal capacity; therefore, it is critical to ensure their survival with genomic stability. The function and survival of melanocytes is regulated by an elaborate network of paracrine factors synthesized mainly by epidermal keratinocytes and dermal fibroblasts. A symbiotic relationship exists between epidermal melanocytes and keratinocytes on the one hand, and between melanocytes and dermal fibroblasts on the other hand. Melanocytes protect epidermal keratinocytes and dermal fibroblasts from the damaging effects of solar radiation, and the latter cells synthesize biochemical mediators that maintain the homeostasis, and regulate the stress response of melanocytes. Disruption of the paracrine network results in pigmentary disorders, due to abnormal regulation of melanin synthesis, and compromise of melanocyte survival or genomic stability. This review provides an update of the current knowledge of keratinocyte‐ and fibroblast‐derived paracrine factors and their contribution to melanocyte physiology, and how their abnormal production is involved in the pathogenesis of common pigmentary disorders.