title: Involvement of intracellular oxidative stress-sensitive pathway in phloxine B-induced photocytotoxicity in human T lymphocytic leukemia cells.
abstract: We investigated the molecular mechanisms underlying phloxine B (PhB)-induced photocytotoxicity in human T lymphocytic leukemia Jurkat cells. In addition to apoptosis-related biochemical events, photo-irradiated PhB generated intracellular reactive oxygen species (ROS), induced phosphorylation of c-Jun-N-terminal kinase (JNK) in an oxidative stress-dependent manner and up-regulated the gene expression of interferon (IFN)-γ, an inducer of diverse apoptosis-related molecules in activated T cells. PhB-induced apoptosis was significantly inhibited by N-acetyl-l-cysteine, but not by catalase, indicating that ROS generation occurred intracellularly, and by SP600125 and AG490, specific inhibitors of JNK and IFN-γ signaling, respectively, confirming their roles in the apoptotic pathway. IFN-γ up-regulation was also inhibited by SP600125, indicating that it was downstream of JNK activation. These results suggest that PhB-induced apoptosis in Jurkat cells partially involves the intracellular oxidative stress-sensitive and T cell-specific IFN-γ pathway. These data present a novel insight into the mechanisms of photocytotoxicity induced by artificial food colorants in human T lymphocytic leukemia cells.
authors.affiliation: Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan.
authors.forename: Hang
authors.initials: H
authors.lastname: Qi
authors.forename: Beiwei
authors.initials: B
authors.lastname: Zhu
authors.forename: Naomi
authors.initials: N
authors.lastname: Abe
authors.forename: Yuko
authors.initials: Y
authors.lastname: Shin
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Murata
authors.forename: Yoshimasa
authors.initials: Y
authors.lastname: Nakamura
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D053148:Caspase 3 / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D053938:DNA Fragmentation; D017484:Dermatitis, Phototoxic / Q000473:pathology*; D010697:Eosine I Bluish / Q000633:toxicity*; D005452:Fluoresceins; D005456:Fluorescent Dyes / Q000633:toxicity*; D006801:Humans; D007202:Indicators and Reagents; D007371:Interferon-gamma / Q000378:metabolism; D048031:JNK Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D019169:Jurkat Cells; D015458:Leukemia, T-Cell / Q000473:pathology*; D008027:Light; D018384:Oxidative Stress / Q000187:drug effects*; D010766:Phosphorylation; D000091402:Prohibitins; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects*
chemical_list: C110400:2',7'-dichlorodihydrofluorescein diacetate; D005452:Fluoresceins; D005456:Fluorescent Dyes; D007202:Indicators and Reagents; C000717328:PHB protein, human; D000091402:Prohibitins; D007371:Interferon-gamma; D002374:Catalase; D048031:JNK Mitogen-Activated Protein Kinases; D053148:Caspase 3; D010697:Eosine I Bluish