title: Trichomonas vaginalis: reactive oxygen species mediates caspase-3 dependent apoptosis of human neutrophils.
abstract: There are many neutrophils in the vaginal discharge from women infected with Trichomonas vaginalis. The aim of our study was to determine whether human neutrophil apoptosis may be regulated by reactive oxygen species (ROS) in response to trichomonads infection. Incubation of human neutrophils with live trichomonads caused marked receptor shedding of CD16, decrease of mitochondrial membrane potential (MMP) and caspase-3 activation in human neutrophils. These proapoptotic effects of T. vaginalis on neutrophils were inhibited by pretreatment of neutrophils with an inhibitor of NADPH oxidase, diphenyleneiodonium chloride (DPI), suggesting an important role of intracellular ROS accumulation in T. vaginalis-triggered apoptosis. Indeed, large amounts of ROS levels were detected in neutrophils incubated with live trichomonads, and were also effectively inhibited by DPI. However, pan-caspase inhibitor z-VAD-fmk or caspase-3 inhibitor z-DEVD-fmk did not affect T. vaginalis-induced ROS generation in neutrophils. These results suggest that ROS-dependent caspase-3 activation plays an important role in apoptosis of human neutrophils induced by T. vaginalis.
authors: Department of Parasitology, Brain Korea 21, Hanyang University College of Medicine, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791, Republic of Korea.
authors: Hyun-Ouk
authors: HO
authors: Song
authors: Myeong-Heon
authors: MH
authors: Shin
authors: Myoung-Hee
authors: MH
authors: Ahn
authors: Duk-Young
authors: DY
authors: Min
authors: Yong-Seok
authors: YS
authors: Kim
authors: Jae-Sook
authors: JS
authors: Ryu
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D053148:Caspase 3 / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors / Q000378:metabolism; D009504:Neutrophils / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D009861:Onium Compounds / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism*; D017452:Receptors, IgG / Q000378:metabolism; D014246:Trichomonas vaginalis / Q000378:metabolism*
chemical_list: D004791:Enzyme Inhibitors; D009861:Onium Compounds; D017382:Reactive Oxygen Species; D017452:Receptors, IgG; C007517:diphenyleneiodonium; D019255:NADPH Oxidases; D053148:Caspase 3