Sebocytes contribute to melasma onset

Melasma is a hyperpigmentary disorder with photoaging features, whose mani-festations appear on specific face areas, rich in sebaceous glands (SGs). To explore the SGs possible contribution to the onset, the expression of pro-melanogenic and inflammatory factors from the SZ9F SG cell line exposed to single or repetitive ultraviolet (UVA) radiation was evaluated. UVA up-modulated the longlast:ng production of alpha-MSH, EDN1, b-FGF, SCF, inflammatory cytokines and mediators. Irradiated SZ95 sebocyte conditioned media increased pigmentation in melanocytes and the expression of senescence markers, pro-inflammatory cytokines, and growth factors regulating melanogenesis in fibroblasts cultures. Cocdtures experiments with skin explants confirmed the role of sebocytes on melanogenesis promotion. The analysis on sebum collected from melasma patients demonstrated that in vivo sebocytes from lesional areas express the UVA-activated pathways markers observed in vitro. Our results indicate sebocytes as one of the actors in melasma pathogenesis, inducing prolonged skin cell stimulation, contributing to localized dermal aging and hyperpigmentation.

Automated summary

This study explores the role of sebaceous glands in the development of melasma. It found that sebocytes exposed to UVA radiation produce a range of substances related to melanogenesis and inflammation. The experiments also demonstrated the promoting effect of sebocytes on melanogenesis and confirmed the existence of these effects in vivo through analysis of sebum from melasma patients.