Abstract:
Retinoic acid-related orphan receptor γt (RORγt) regulates immune responses and its impaired function contributes to inflammatory and autoimmune diseases and may promote skin cancer. Synthetic inverse RORγt agonists block the production of Th17-associated cytokines including interleukin (IL)-17A and IL-22 and are under investigation for treatment of such pathologies. Unintentional RORγt activation in skin, following exposure to environmental chemicals, may promote inflammatory skin disease. Parabens and UV-filters, frequently used as additives in cosmetics and body care products, are intensively inspected for endocrine disrupting properties. This study assessed whether such compounds can interfere with RORγ activity using a previously established tetracycline-inducible reporter gene assay in CHO cells. These transactivation experiments revealed hexylparaben, benzylparaben and benzophenone-10 as RORγ agonists (EC50 values: 144 ± 97 nM, 3.39 ± 1.74 µM and 1.67 ± 1.04 µM, respectively), and they could restore RORγ activity after suppression by an inverse agonist. Furthermore, they enhanced RORγt-dependent transcription of the pro-inflammatory IL-17A and/or IL-22 genes in the murine T-cell model EL4. Virtual screening of a cosmetics database for structurally similar chemicals and in vitro testing of the most promising hits revealed benzylbenzoate, benzylsalicylate and 4-methylphenylbenzoate as RORγ agonists (low micromolar EC50 values). Moreover, an analysis of mixtures of the newly identified RORγ agonists suggested additive effects. This study presents novel RORγ(t) agonistic structural scaffolds. By activating RORγ(t) the identified parabens and UV-filters may potentially aggravate pathophysiological conditions, especially skin diseases where highest exposure of such chemicals can be expected. Follow-up studies should assess whether such compounds, either alone or as mixtures, can reach relevant concentrations in tissues and target cells to activate RORγ(t) in vivo.
摘要:
视黄酸相关的孤儿受体γt(RORγt)调节免疫反应,其功能受损导致炎症和自身免疫性疾病,并可能促进皮肤癌。合成的反向RORγt激动剂阻断Thl7相关细胞因子(包括白细胞介素(IL)-17A和IL-22)的产生,并且正在研究这些病症的治疗。皮肤中无意的RORγt激活,在接触环境化学物质后,可促进炎症性皮肤病。对羟基苯甲酸酯和紫外线过滤器,经常用作化妆品和身体护理产品的添加剂,被严格检查内分泌干扰特性。该研究使用先前在CHO细胞中建立的四环素诱导型报告基因测定来评估此类化合物是否会干扰RORγ活性。这些反式激活实验揭示了对羟基苯甲酸己酯,对羟基苯甲酸苄酯和二苯甲酮-10作为RORγ激动剂(EC50值:144±97nM,3.39±1.74µM和1.67±1.04µM,分别),它们可以在被反向激动剂抑制后恢复RORγ活性。此外,它们增强了鼠T细胞模型EL4中促炎性IL-17A和/或IL-22基因的RORγt依赖性转录。虚拟筛选结构相似的化学品的化妆品数据库和最有希望的命中的体外测试显示苯甲酸苄酯,作为RORγ激动剂的水杨酸苄酯和苯甲酸4-甲基苯酯(低的微摩尔EC50值)。此外,对新鉴定的RORγ激动剂混合物的分析提示了加性效应.本研究提出了新型RORγ(t)激动结构支架。通过激活RORγ(t),鉴定的对羟基苯甲酸酯和紫外线过滤剂可能会加重病理生理状况,尤其是皮肤疾病,可以预期这些化学物质的最高暴露。后续研究应评估此类化合物是否,单独或作为混合物,可以在组织和靶细胞中达到相关浓度以激活体内RORγ(t)。