IFN ‐ γ inhibits basal and α ‐ MSH ‐induced melanogenesis

Summary Inflammatory cytokines are closely related to pigmentary changes. In this study, the effects of IFN‐ γ on melanogenesis were investigated. IFN‐ γ inhibits basal and α ‐MSH‐induced melanogenesis in B16 melanoma cells and normal human melanocytes. MITF mRNA and protein expressions were significantly inhibited in response to IFN‐ γ . IFN‐ γ inhibited CREB binding to the MITF promoter but did not affect CREB phosphorylation. Instead, IFN‐ γ inhibited the association of CBP and CREB through the increased association between CREB binding protein (CBP) and STAT1. These findings suggest that IFN‐ γ inhibits both basal and α ‐MSH‐induced melanogenesis by inhibiting MITF expression. The inhibitory action of IFN‐ γ in α ‐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‐ γ plays a role in controlling inflammation‐ or UV‐induced pigmentary changes.