title: Trichomonas vaginalis induces IL-1β production in a human prostate epithelial cell line by activating the NLRP3 inflammasome via reactive oxygen species and potassium ion efflux.
abstract: Trichomonas vaginalis is a sexually transmitted protozoan parasite that causes vaginitis in women, and urethritis and prostatitis in men. IL-1β is synthesized as immature pro-IL-1β, which is cleaved by activated caspase-1. Caspase-1 is, in turn, activated by a multi-protein complex known as an inflammasome. In this study, we investigated the inflammatory response of a prostate epithelial cell line (RWPE-1) to T. vaginalis and, specifically, the capacity of T. vaginalis to activate the NLRP3 inflammasome.
  
  
  
  RWPE-1 cells were stimulated by live T. vaginalis, and subsequent expression of pro-IL-1β, IL-1β, NLRP3, ASC and caspase-1 was determined by real-time PCR and Western blotting. IL-1β and caspase-1 production was also measured by ELISA. To evaluate the effects of NLRP3 and caspase-1 on IL-1β production, the activated RWPE-1 cells were transfected with small interfering RNAs to silence the NLRP3 and caspase-1 genes. Activation of the NLRP3 inflammasome was observed by fluorescence microscopy. Intracellular reactive oxygen species (ROS) were evaluated by spectrofluorometry.
  
  
  
  When RWPE-1 cells were stimulated with live T. vaginalis, the mRNA and protein expression of IL-1β, NLRP3, ASC, and caspase-1 increased. Moreover, silencing of NLRP3 and caspase-1 attenuated T. vaginalis-induced IL-1β secretion. The NADPH oxidase inhibitor DPI and high extracellular potassium ion suppressed the production of IL-1β, caspase-1, and the expression of NLRP3 and ASC proteins. The specific NF-κB inhibitor, Bay 11-7082, inhibited IL-1β production, and also inhibited the production of caspase-1, ASC and NLRP3 proteins.
  
  
  
  T. vaginalis induces the formation of the NLRP3 inflammasome in human prostate epithelial cells via ROS and potassium ion efflux, and this results in IL-1β production. This is the first evidence for activation of the NLRP3 inflammasome in the inflammatory response by prostate epithelial cells infected with T. vaginalis. Prostate 76:885-896, 2016. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Environmental Biology and Medical Parasitology, Hanyang University College of Medicine, Hanyang University, Seoul, Korea.|Department of Biomedical Science, Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul, Korea.
authors.forename: Na-Yeong
authors.initials: NY
authors.lastname: Gu
authors.affiliation: Department of Environmental Biology and Medical Parasitology, Hanyang University College of Medicine, Hanyang University, Seoul, Korea.|Department of Biomedical Science, Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul, Korea.
authors.forename: Jung-Hyun
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Environmental Biology and Medical Parasitology, Hanyang University College of Medicine, Hanyang University, Seoul, Korea.|Department of Biomedical Science, Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul, Korea.
authors.forename: Ik-Hwan
authors.initials: IH
authors.lastname: Han
authors.affiliation: Department of Environmental Biology and Medical Parasitology, Hanyang University College of Medicine, Hanyang University, Seoul, Korea.
authors.forename: Su-Jeong
authors.initials: SJ
authors.lastname: Im
authors.affiliation: Department of Environmental Biology and Medical Parasitology, Hanyang University College of Medicine, Hanyang University, Seoul, Korea.
authors.forename: Min-Young
authors.initials: MY
authors.lastname: Seo
authors.affiliation: Department of Microbiology, Hanyang University College of Medicine, Seoul, Korea.
authors.forename: Yong-Hoon
authors.initials: YH
authors.lastname: Chung
authors.affiliation: Department of Environmental Biology and Medical Parasitology, Hanyang University College of Medicine, Hanyang University, Seoul, Korea.|Department of Biomedical Science, Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul, Korea.
authors.forename: Jae-Sook
authors.initials: JS
authors.lastname: Ryu
mesh_terms: D053468:CARD Signaling Adaptor Proteins; D020170:Caspase 1 / Q000235:genetics / Q000502:physiology; D002460:Cell Line; D003598:Cytoskeletal Proteins; D004847:Epithelial Cells / Q000737:chemistry / Q000378:metabolism; D005260:Female; D015870:Gene Expression; D006801:Humans; D058847:Inflammasomes / Q000502:physiology*; D053583:Interleukin-1beta / Q000096:biosynthesis* / Q000235:genetics; D008297:Male; D008856:Microscopy, Fluorescence; D016328:NF-kappa B / Q000378:metabolism; D000071199:NLR Family, Pyrin Domain-Containing 3 Protein / Q000235:genetics / Q000502:physiology*; D011188:Potassium / Q000378:metabolism; D011467:Prostate / Q000737:chemistry / Q000378:metabolism*; D011472:Prostatitis / Q000469:parasitology; D012333:RNA, Messenger / Q000032:analysis; D034741:RNA, Small Interfering / Q000235:genetics; D017382:Reactive Oxygen Species / Q000032:analysis / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D014162:Transfection; D014245:Trichomonas Infections / Q000503:physiopathology; D014246:Trichomonas vaginalis / Q000502:physiology*
chemical_list: D053468:CARD Signaling Adaptor Proteins; D003598:Cytoskeletal Proteins; D058847:Inflammasomes; D053583:Interleukin-1beta; D016328:NF-kappa B; D000071199:NLR Family, Pyrin Domain-Containing 3 Protein; C453881:NLRP3 protein, human; C402202:PYCARD protein, human; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; D020170:Caspase 1; D011188:Potassium
keywords: IL-1β; NLRP3 inflammasome; Trichomonas vaginalis; prostate epithelial cell