Concise Communication: Kynurenine inhibits melanogenesis in human melanocyte‐keratinocyte co‐cultures, and in a reconstructed 3D skin model

xlomafota13 shared this article with you from Inoreader Concise Communication: Kynurenine inhibits melanogenesis in human melanocyte‐keratinocyte co‐cultures, and in a reconstructed 3D skin model Via Experimental Dermatology Abstract Kynurenine (KYN), the most abundant metabolite of tryptophan, is classically associated with immune tolerance and tumor immune escape. In the last years, KYN is in the spotlight in other biological processes. Here, we showed that KYN inhibited tyrosinase expression and melanin content in primary human melanocyte and keratinocyte co-cultures. Furthermore, KYN decreased melanosome content in a 3D human skin reconstruction model. In these experiments, we used tyrosine + NH4Cl to induce pigmentation. We compared the inhibitory effect of KYN on melanogenesis with the already know inhibitory effect promoted by IFN-γ. Since increased KYN production depends on the IFN-γ-inducible enzyme indoleamine-2,3-dioxygenase (IDO), we propose that part of the effect of IFN-γ on melanogenesis involves KYN production. From that, we tested if, during melanogenesis, changes in tryptophan metabolism would occur. For this purpose, we measured tryptophan, KYN, and downstream product s along with pigmentation. There were no significant changes in Trp metabolism, except for the high consumption of kynurenic acid. Our data identify the skin as a potential target for the action of KYN relevant for skin physiology and pigmentation. The results are discussed concerning the high production of KYN in skin inflammatory disorders and cancer. View on the web Inoreader. Take back control of your news feed. Follow us on Twitter and Facebook.