title: Effect of 17beta-estradiol on tumor necrosis factor-alpha-induced cytotoxicity in the human peripheral T lymphocytes.
abstract: We determined the effect of 17beta-estradiol on tumor necrosis factor alpha (TNF-alpha)-induced cytotoxicity in human peripheral T lymphocytes (T cells) using lactate dehydrogenase assay. Treatment with 17beta-estradiol (1-100 nM) for 24 h showed dose-dependent reduction of TNF-alpha-induced cytotoxicity in T cells. To further evaluate the mechanism of 17beta-estradiol on TNF-alpha-induced cytotoxicity in T cells, we identified estrogen receptor (ER) protein in T cells using immunocytochemistry and used the pure ER antagonist ICI 172,780. ERalpha immunoreactivity was clearly observed in T cells. ERbeta immunoreactivity was also detected in some T cells. ICI 172,780 (10(-7) M) alone did not affect cytotoxicity in T cells, however, ICI 172,780 (10(-7) M) completely abolished 17beta-estradiol cytoprotective effects in T cells. TNF-alpha tended to increase nuclear factor kappaB (NF-kappaB) protein levels in nuclear extracts but it did not reach statistical significance by Western blotting. In contrast, NF-kappaB protein levels in nuclear extracts followed by TNF-alpha with 17beta-estradiol treatment were significantly increased compared with NF-kappaB protein levels in untreated group. NF-kappaB blocker pyrrolidinedithiocarbamate (PDTC) (10(-4) M) alone did not affect cytotoxicity in T cells. In contrast, PDTC (10(-4) M) completely abolished 17beta-estradiol cytoprotective effects in T cells. Caspase -3/-7 activity was significantly increased followed by TNF-alpha, and 17beta-estradiol treatment significantly reduced the increment. The present studies suggest the protective effect of 17beta-estradiol on TNF-alpha-induced cytotoxicity through ERs in T cells and that NF-kappaB activation and caspase suppression may be involved in the mechanism.
authors.affiliation: Department of Endocrine, Metabolism and Nephrology, Kochi Medical School, Nankoku 783-8505, Japan. takaot@med.kochi-u.ac.jp
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Takao
authors.forename: Chizuru
authors.initials: C
authors.lastname: Kumagai
authors.forename: Naoko
authors.initials: N
authors.lastname: Hisakawa
authors.forename: Reiko
authors.initials: R
authors.lastname: Matsumoto
authors.forename: Kozo
authors.initials: K
authors.lastname: Hashimoto
mesh_terms: D000328:Adult; D053148:Caspase 3; D020169:Caspases / Q000032:analysis / Q000378:metabolism; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic / Q000187:drug effects*; D004958:Estradiol / Q000494:pharmacology*; D004965:Estrogen Antagonists / Q000494:pharmacology; D020847:Estrogen Receptor Modulators / Q000494:pharmacology; D047628:Estrogen Receptor alpha / Q000032:analysis; D047629:Estrogen Receptor beta / Q000032:analysis; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D007770:L-Lactate Dehydrogenase / Q000032:analysis; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism; D011392:Proline / Q000031:analogs & derivatives* / Q000494:pharmacology; D013601:T-Lymphocytes / Q000737:chemistry / Q000187:drug effects / Q000276:immunology*; D013859:Thiocarbamates / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
chemical_list: D004965:Estrogen Antagonists; D020847:Estrogen Receptor Modulators; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D016328:NF-kappa B; D013859:Thiocarbamates; D014409:Tumor Necrosis Factor-alpha; C066229:prolinedithiocarbamate; D004958:Estradiol; D011392:Proline; D007770:L-Lactate Dehydrogenase; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases