title: Indoxyl 3-sulfate stimulates Th17 differentiation enhancing phosphorylation of c-Src and STAT3 to worsen experimental autoimmune encephalomyelitis.
abstract: Although AhR activation regulates CD4T cell differentiation, how it works has yet to be elucidated. In the present study, using in vitro Th17 differentiation model, we examined effects of AhR activation by indoxyl 3-sulfate (I3S), a uremic toxin, on Th17 differentiation and investigated underlying mechanisms. I3S increased expression of RORγt, the master transcription factor for Th17 differentiation, and stimulated Th17 differentiation, in a comparative manner as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a prototypical AhR ligand. Activation of STAT3, which is phosphorylated by the IL-6 signaling pathways and thus is necessary for Th17 differentiation, was strongly stimulated by I3S and TCDD. Phosphorylation of c-Src, which was shown to be activated by AhR ligands, was also increased by I3S and TCDD, and blocking of c-Src activity by 4-amino-5-(4-chlorophenyl)-7-(t-butyl) pyrazolo[3,4-d]pyrimidine (PP2) inhibited phosphorylation of both c-Src and STAT3, raising a possibility that stimulatory activities of I3S and TCDD on Th17 differentiation could be exerted via increased phosphorylation of c-Src, which in turn stimulates STAT3 activation. Finally, we found that I3S worsened experimental autoimmune encephalomyelitis (EAE), which is primarily mediated by Th17 cells, enhancing the frequency of IL-17-producing cells in draining lymph nodes.
authors: Department of Biology, Changwon National University, Changwon, Kyungnam 641-773, South Korea.
authors: Sung-Jun
authors: SJ
authors: Hwang
authors: You-Jung
authors: YJ
authors: Hwang
authors: Mi-Ok
authors: MO
authors: Yun
authors: Jong-Hee
authors: JH
authors: Kim
authors: Gap-Soo
authors: GS
authors: Oh
authors: Joo-Hung
authors: JH
authors: Park
mesh_terms: D000818:Animals; D000081247:CSK Tyrosine-Protein Kinase; D002454:Cell Differentiation / Q000187:drug effects; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000139:chemically induced / Q000276:immunology* / Q000378:metabolism*; D007200:Indican / Q000494:pharmacology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D010766:Phosphorylation / Q000187:drug effects; D000072317:Polychlorinated Dibenzodioxins / Q000494:pharmacology; D050796:STAT3 Transcription Factor / Q000378:metabolism*; D058504:Th17 Cells / Q000166:cytology / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D019061:src-Family Kinases / Q000378:metabolism*
chemical_list: D000072317:Polychlorinated Dibenzodioxins; D050796:STAT3 Transcription Factor; C494087:Stat3 protein, mouse; D000081247:CSK Tyrosine-Protein Kinase; D019061:src-Family Kinases; D007200:Indican