title: Role of Ca/CaN/NFAT signaling in IL-4 expression by splenic lymphocytes exposed to phthalate (2-ethylhexyl) ester in spleen lymphocytes.
abstract: The aims of present study were to investigate the effect of phthalate (2-ethylhexyl) ester (DEHP) and mono-(2-ethylhexyl) phthalate (MEHP) on Th1/Th2 balance signaling for interleukin 4 (IL-4) expression in splenic lymphocytes, and contribution of MEHP to any hypothesized changes in vitro. Primary splenic lymphocytes were exposed to DEHP/MEHP. ELISA and Western blotting were used to detect proteins. Confocal-microscopy was used to examine nuclear translocation. Nuclear factor of activated T cells (NFAT) DNA binding activity was examined by electrophoretic mobility-shift assay. DEHP significantly increased IL-4 and interferon gamma (IFN-γ) level, and reduced Th1/Th2 ratio (reflected by IFN-γ/IL-4) with 5 μg/L Concanavalin A (ConA) treatment. While MEHP reduced Th1/Th2 ratio (represented by IFN-γ/IL-6). IL-4 mRNA was significantly increased by DEHP but not by MEHP after PMA and Ion treatment. DEHP significantly inhibited NFATp protein in cytosol and nucleus. DEHP augmented nuclear translocation of NFATc in transfected EL4 cells and NFAT DNA-binding activity. DEHP-mediated enhancement of calcium-dependent phosphatase calcineurin (CaN) protein, and NFAT and IL-4 expression were abrogated by calcium antagonist verapamil and CaN inhibitor tarcolimus. Ca(2+)/calmodulin antagonist chlorpromazine significantly suppressed IL-4 and CaN production with no NFAT mRNA change. Our study suggests that DEHP and MEHP impact Th1/Th2 balance by modulating different cytokines. DEHP-affected IL-4 expression through Ca/CaN/NFAT signaling pathway, but no effect was discovered for MEHP.
authors.affiliation: Department of Toxicology, School of Public Health, Shenyang Medical College, Shenyang, 110034, Liaoning, China, peixiucongdoctor@yeah.net.
authors.forename: Xiucong
authors.initials: X
authors.lastname: Pei
authors.forename: Zhiwen
authors.initials: Z
authors.lastname: Duan
authors.forename: Mingyue
authors.initials: M
authors.lastname: Ma
authors.forename: Yuming
authors.initials: Y
authors.lastname: Zhang
authors.forename: Li
authors.initials: L
authors.lastname: Guo
mesh_terms: D000818:Animals; D019703:Calcineurin / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D004051:Diethylhexyl Phthalate / Q000031:analogs & derivatives / Q000494:pharmacology; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D015847:Interleukin-4 / Q000235:genetics*; D018655:Lymphocyte Count; D016131:Lymphocyte Subsets / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D051379:Mice; D050778:NFATC Transcription Factors / Q000378:metabolism*; D015398:Signal Transduction; D013154:Spleen / Q000276:immunology / Q000378:metabolism*; D018417:Th1 Cells / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D018418:Th2 Cells / Q000187:drug effects / Q000276:immunology / Q000378:metabolism
chemical_list: D050778:NFATC Transcription Factors; D015847:Interleukin-4; D004051:Diethylhexyl Phthalate; D019703:Calcineurin; C016599:mono-(2-ethylhexyl)phthalate; D002118:Calcium