title: Inhibitory effects of azole-type fungicides on interleukin-17 gene expression via retinoic acid receptor-related orphan receptors α and γ.
abstract: The retinoic acid receptor-related orphan receptors α and γ (RORα and RORγ), are key regulators of helper T (Th)17 cell differentiation, which is involved in the innate immune system and autoimmune disorders. However, it remains unclear whether environmental chemicals, including pesticides, have agonistic and/or antagonistic activity against RORα/γ. In this study, we investigated the RORα/γ activity of several azole-type fungicides, and the effects of these fungicides on the gene expression of interleukin (IL)-17, which mediates the function of Th17 cells. In the ROR-reporter gene assays, five azole-type fungicides (imibenconazole, triflumizole, hexaconazole, tetraconazole and imazalil) suppressed RORα- and/or RORγ-mediated transcriptional activity as did benzenesulphonamide T0901317, a ROR inverse agonist and a liver X receptor (LXR) agonist. In particular, imibenconazole, triflumizole and hexaconazole showed RORγ inverse agonistic activity at concentrations of 10(-6)M. However, unlike T0901317, these fungicides failed to show any LXRα/β agonistic activity. Next, five azole-type fungicides, showing ROR inverse agonist activity, were tested on IL-17 mRNA expression in mouse T lymphoma EL4 cells treated with phorbol myristate acetate and ionomycin. The quantitative RT-PCR analysis revealed that these fungicides suppressed the expression of IL-17 mRNA without effecting RORα and RORγ mRNA levels. In addition, the inhibitory effect of imibenconazole as well as that of T0901317 was absorbed in RORα/γ-knocked down EL4 cells. Taken together, these results suggest that some azole-type fungicides inhibit IL-17 production via RORα/γ. This also provides the first evidence that environmental chemicals can act as modulators of IL-17 expression in immune cells.
authors.affiliation: Hokkaido Institute of Public Health, Kita-19, Nishi-12, Kita-ku, Sapporo 060-0819, Japan. kojima@iph.pref.hokkaido.jp
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kojima
authors.forename: Ryuta
authors.initials: R
authors.lastname: Muromoto
authors.forename: Miki
authors.initials: M
authors.lastname: Takahashi
authors.forename: Shinji
authors.initials: S
authors.lastname: Takeuchi
authors.forename: Yukimasa
authors.initials: Y
authors.lastname: Takeda
authors.forename: Anton M
authors.initials: AM
authors.lastname: Jetten
authors.forename: Tadashi
authors.initials: T
authors.lastname: Matsuda
mesh_terms: D000818:Animals; D000935:Antifungal Agents / Q000008:administration & dosage / Q000494:pharmacology*; D001393:Azoles / Q000008:administration & dosage / Q000494:pharmacology*; D016466:CHO Cells; D019556:COS Cells; D045744:Cell Line, Tumor; D002522:Chlorocebus aethiops; D006224:Cricetinae; D003412:Cricetulus; D004305:Dose-Response Relationship, Drug; D005786:Gene Expression Regulation / Q000187:drug effects*; D017930:Genes, Reporter; D020381:Interleukin-17 / Q000235:genetics*; D016399:Lymphoma, T-Cell / Q000378:metabolism; D051379:Mice; D012333:RNA, Messenger / Q000378:metabolism; D018168:Receptors, Retinoic Acid / Q000378:metabolism*; D000072482:Retinoic Acid Receptor alpha; D020133:Reverse Transcriptase Polymerase Chain Reaction; D058504:Th17 Cells / Q000378:metabolism; D000097768:Retinoic Acid Receptor gamma
chemical_list: D000935:Antifungal Agents; D001393:Azoles; D020381:Interleukin-17; D012333:RNA, Messenger; D018168:Receptors, Retinoic Acid; D000072482:Retinoic Acid Receptor alpha; D000097768:Retinoic Acid Receptor gamma; C000607072:Rara protein, mouse