IFN-γ inhibits basal and α-MSH-induced melanogenesis.

Abstract

Inflammatory cytokines are closely related to pigmentary changes. In this study,

the effects of IFN-gamma on melanogenesis were investigated. IFN-gamma inhibits

basal and alpha-MSH-induced melanogenesis in B16 melanoma cells and normal human

melanocytes. MITF mRNA and protein expressions were significantly inhibited in

response to IFN-gamma. IFN-gamma inhibited CREB binding to the MITF promoter but

did not affect CREB phosphorylation. Instead, IFN-gamma inhibited the association

of CBP and CREB through the increased association between CREB binding protein

(CBP) and STAT1. These findings suggest that IFN-gamma inhibits both basal and

alpha-MSH-induced melanogenesis by inhibiting MITF expression. The inhibitory

action of IFN-gamma in alpha-MSH-induced melanogenesis is likely to be associated

with the sequestration of CBP via the association between CBP and STAT1. These

data suggest that IFN-gamma plays a role in controlling inflammation- or

UV-induced pigmentary changes.