title: LPS induces melanogenesis through p38 MAPK activation in human melanocytes.
abstract: We have observed that lipopolysaccharide (LPS) induces pigmentation in melanocytes and in this study have examined whether these responses are mediated by the p38 mitogen-activated protein kinase (MAPK) signaling pathway. LPS appears to stimulate the pigmentation of melanocytes and cultured skin. LPS was found to induce the expression of microphthalmia-associated transcription factor (MITF) and tyrosinase protein in cells. Stimulation of melanocytes with LPS led to time dependent phosphorylation of p38 MAPK. Furthermore, p38 MAPK functionally regulated the LPS-induced melanin formation in melanocytes; a p38 MAPK inhibitor, SB203580, almost completely attenuated the LPS-mediated up-regulation of melanin synthesis and induction of MITF and tyrosinase expression. These findings indicate that activation of p38 MAPK plays an important role in LPS-induced melanogenesis by up-regulating MITF and tyrosinase expression.
authors.affiliation: Department of Dermatology, Ajou University School of Medicine, Suwon, South Korea.
authors.forename: Joo Hee
authors.initials: JH
authors.lastname: Ahn
authors.forename: Sun Hee
authors.initials: SH
authors.lastname: Jin
authors.forename: Hee Young
authors.initials: HY
authors.lastname: Kang
mesh_terms: D002454:Cell Differentiation / Q000187:drug effects; D019070:Cell Lineage / Q000187:drug effects; D002478:Cells, Cultured; D005260:Female; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology*; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000235:genetics / Q000276:immunology; D008297:Male; D008543:Melanins / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D008544:Melanocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D051739:Microphthalmia-Associated Transcription Factor / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D011725:Pyridines / Q000494:pharmacology; D012880:Skin Pigmentation / Q000187:drug effects; D015533:Transcriptional Activation; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000276:immunology
chemical_list: D007093:Imidazoles; D008070:Lipopolysaccharides; C497234:MITF protein, human; D008543:Melanins; D051739:Microphthalmia-Associated Transcription Factor; D011725:Pyridines; C433788:lipopolysaccharide, E. coli O26-B6; D014442:Monophenol Monooxygenase; D048051:p38 Mitogen-Activated Protein Kinases; C093642:SB 203580