title: Malassezin, a novel agonist of the aryl hydrocarbon receptor from the yeast Malassezia furfur, induces apoptosis in primary human melanocytes.
abstract: Pityriasis versicolor is the most common skin mycosis in humans worldwide. Yeasts of the genus Malassezia, particularly M. furfur, a saprophyte occurring widely on human skin, are generally regarded as the causative agents. Pityriasis versicolor is often accompanied by a long-lasting depigmentation that persists even after successful antimycotic therapy. M. furfur is able to convert tryptophan into a variety of indole alkaloids, some of them showing biological properties that correlate well with certain clinical features of pityriasis versicolor. This suggests a possible role for these compounds in the depigmentation process. We now report that human melanocytes undergo apoptosis when exposed to the crude mixture of tryptophan metabolites from M. furfur. The active compound was identified as malassezin, previously isolated by us from the same source and characterized as an agonist of the aryl hydrocarbon (Ah) receptor. The compound could, therefore, contribute to the marked depigmentation observed during the course of pityriasis versicolor.
authors.affiliation: Center of Andrology and Dermatology, Justus Liebig-Universität, Gaffkystrasse 14, 35385 Giessen, Germany. kraemer@innere.med.uni-giessen.de
authors.forename: Hans-Joachim
authors.initials: HJ
authors.lastname: Krämer
authors.forename: Monika
authors.initials: M
authors.lastname: Podobinska
authors.forename: Andrea
authors.initials: A
authors.lastname: Bartsch
authors.forename: Achim
authors.initials: A
authors.lastname: Battmann
authors.forename: Wiebke
authors.initials: W
authors.lastname: Thoma
authors.forename: August
authors.initials: A
authors.lastname: Bernd
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Kummer
authors.forename: Bernhard
authors.initials: B
authors.lastname: Irlinger
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Steglich
authors.forename: Peter
authors.initials: P
authors.lastname: Mayser
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D053453:Caspase 9; D020169:Caspases / Q000378:metabolism; D002478:Cells, Cultured; D002855:Chromatography, Thin Layer; D020552:Comet Assay; D006801:Humans; D007211:Indoles / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008290:Malassezia / Q000737:chemistry*; D008544:Melanocytes / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D008854:Microscopy, Electron; D015394:Molecular Structure; D018336:Receptors, Aryl Hydrocarbon / Q000819:agonists* / Q000378:metabolism
chemical_list: D007211:Indoles; D018336:Receptors, Aryl Hydrocarbon; C436511:malassezin; D007770:L-Lactate Dehydrogenase; C506433:CASP9 protein, human; D053453:Caspase 9; D020169:Caspases