title: Resveratrol enhances perforin expression and NK cell cytotoxicity through NKG2D-dependent pathways.
abstract: In a previous report, we showed that the in vivo cytotoxic activity of the natural killer (NK) cells isolated from resveratrol-pretreated rats is significantly enhanced compared with that of the non-pretreated rats; however, the underlying mechanism remains unclear. In the present study, we use cultured NK92 cell line to examine the possible signaling pathways underlying the resveratrol-induced activation. Using cultured K562, HepG2, and A549 cells as targets, we show that resveratrol pretreatment increases NK cell cytotoxicity in a dose-dependent manner. The enhanced cytotoxic effect is accompanied by increases in JNK and ERK-1/2 MAP kinase activity and perforin expression. Moreover, the expression of NKG2D, an upstream signaling molecule of the MAP kinases pathway, is also enhanced. Resveratrol-enhanced perforin expression and cytotoxic activity are effectively inhibited by pretreatment with the inhibitors of JNK (SP600125), ERK-1/2 (PD98059), or by siRNAs against JNK-1 and ERK-2. However, the inhibitors or siRNA to p38 exhibits no effect. Since IL-2 has been shown to induce NKG2D expression and perforin release, we therefore, examined whether IL-2 and resveratrol act in parallel. We show that IL-2 also stimulates perforin expression, however, when treated together with resveratrol, they exhibit no additive effect. The results suggest that in NK92 cells, resveratrol may act via a similar or overlapping pathway as that of IL-2, to enhance perforin expression and cytotoxic activity. Data presented strongly indicate that resveratrol act via NKG2D-dependent JNK and ERK-1/2 pathways.
authors.affiliation: Department of Physiology, College of Medicine, Chang Gung University, Kweishan, Taoyuan 333, Taiwan.
authors.forename: Chia-Chen
authors.initials: CC
authors.lastname: Lu
authors.forename: Jan-Kan
authors.initials: JK
authors.lastname: Chen
mesh_terms: D000975:Antioxidants / Q000494:pharmacology; D002460:Cell Line; D003602:Cytotoxicity, Immunologic / Q000187:drug effects / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D007113:Immunity, Innate / Q000187:drug effects* / Q000502:physiology; D007376:Interleukin-2 / Q000494:pharmacology; D048031:JNK Mitogen-Activated Protein Kinases / Q000187:drug effects / Q000378:metabolism; D007694:Killer Cells, Natural / Q000187:drug effects* / Q000378:metabolism; D008213:Lymphocyte Activation / Q000187:drug effects / Q000502:physiology; D020935:MAP Kinase Signaling System / Q000187:drug effects* / Q000502:physiology; D055655:NK Cell Lectin-Like Receptor Subfamily K / Q000187:drug effects* / Q000378:metabolism; D054353:Perforin / Q000819:agonists* / Q000378:metabolism; D034622:RNA Interference / Q000187:drug effects / Q000502:physiology; D000077185:Resveratrol; D013267:Stilbenes / Q000494:pharmacology*; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology
chemical_list: D000975:Antioxidants; D004791:Enzyme Inhibitors; D007376:Interleukin-2; C527085:KLRK1 protein, human; D055655:NK Cell Lectin-Like Receptor Subfamily K; D013267:Stilbenes; D054353:Perforin; D048049:Extracellular Signal-Regulated MAP Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D000077185:Resveratrol