mcc-950 and Rosacea

Rosacea is a chronic inflammatory skin disease characterized by immune response-dependent erythema and pustules. Although the precise etiology of rosacea remains elusive, its pathogenesis is reportedly associated with an increased level of antimicrobial peptide LL-37. However, molecular mechanisms underlying the progression of rosacea via LL-37 remain poorly understood. Here, we examined the potential role of LL-37 in rosacea-like skin inflammatory phenotypes at a molecular level. Our in vitro data demonstrated that LL-37 promotes NLRP3-mediated inflammasome activation in lipopolysaccharide-primed macrophages, indicated by the processing of caspase-1 and IL-1β. LL-37 was internalized into the cytoplasm of macrophages through P2X7 receptor-mediated endocytosis. Intracellular LL-37 triggered the assembly and activation of NLRP3-ASC inflammasome complex by facilitating lysosomal destabilization. Consistent with these in vitro results, intradermal LL-37 administration induced in vivo caspase-1 activation and ASC speck formation in the skin of Nlrp3-expressing, but not in Nlrp3-deficient, mice. Intradermal injection of LL-37 elicited profound recruitment of inflammatory Gr1

Topics: Animals; Antimicrobial Cationic Peptides; Caspase 1; Cathelicidins; Cells, Cultured; Female; Furans; Indenes; Inflammasomes; Inflammation; Interleukin-1beta; Mice; Mice, Inbred C57BL; NLR Family, Pyrin Domain-Containing 3 Protein; Rosacea; Sulfonamides