UV-B-triggered induction of vitamin D3 metabolism differentially affects antimicrobial peptide expression in keratinocytes

摘要

Antimicrobial peptides (AMPs) are important effectors in cutaneous innate immunity as antibiotics and signaling molecules in the defense against microbes.1 The regulation of AMP expression and function in the skin is not completely understood. In theJournal, Glaser et al recently reported in an elegant study that the AMPs human beta-defensin (HBD)-2, HBD3, ribonuclease (RNAse) 7, and psoriasin are induced in human keratinocytes on UV-B treatment in vitro and in vivo. In another recent study, expression of a different important AMP in skin-cathelicidin-was only enhanced after UV-B treatment -in vivo,whereas in cultured primary human epidermal keratinocytes (NHEKs), no induction of cathelicidin after UV-B irradiation was observed. This observation could not be conclusively explained to date.