title: Vibrio vulnificus VvpE Stimulates IL-1β Production by the Hypomethylation of the IL-1β Promoter and NF-κB Activation via Lipid Raft-Dependent ANXA2 Recruitment and Reactive Oxygen Species Signaling in Intestinal Epithelial Cells.
abstract: An inflammatory response is a hallmark of necrosis evoked by bacterial pathogens. Vibrio vulnificus, VvpE, is an elastase that is responsible for tissue necrosis and inflammation; however, the molecular mechanism by which it regulates host cell death has not been characterized. In the present study, we investigate the cellular mechanism of VvpE with regard to host cell death and the inflammatory response of human intestinal epithelial (INT-407) cells. The recombinant protein (r)VvpE (50 pg/ml) caused cytotoxicity mainly via necrosis coupled with IL-1β production. The necrotic cell death induced by rVvpE is highly susceptible to the knockdown of annexin A (ANXA)2 and the sequestration of membrane cholesterol. We found that rVvpE induces the recruitment of NADPH oxidase 2 and neutrophil cytosolic factor 1 into membrane lipid rafts coupled with ANXA2 to facilitate the production of reactive oxygen species (ROS). The bacterial signaling of rVvpE through ROS production is uniquely mediated by the phosphorylation of redox-sensitive transcription factor NF-κB. The silencing of NF-κB inhibited IL-1β production during necrosis. rVvpE induced hypomethylation and region-specific transcriptional occupancy by NF-κB in the IL-1β promoter and has the ability to induce pyroptosis via NOD-, LRR-, and pyrin domain-containing 3 inflammasome. In a mouse model of V. vulnificus infection, the mutation of the vvpE gene from V. vulnificus negated the proinflammatory responses and maintained the physiological levels of the proliferation and migration of enterocytes. These results demonstrate that VvpE induces the hypomethylation of the IL-1β promoter and the transcriptional regulation of NF-κB through lipid raft-dependent ANXA2 recruitment and ROS signaling to promote IL-1β production in intestinal epithelial cells.
authors.affiliation: Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science, Seoul National University, Seoul 151-741, South Korea; Brain Korea 21 Program for Leading Universities and Students (BK21 PLUS) Creative Veterinary Research Center, Seoul National University, Seoul 151-741, South Korea; and.
authors.forename: Sei-Jung
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science, Seoul National University, Seoul 151-741, South Korea; Brain Korea 21 Program for Leading Universities and Students (BK21 PLUS) Creative Veterinary Research Center, Seoul National University, Seoul 151-741, South Korea; and.
authors.forename: Young Hyun
authors.initials: YH
authors.lastname: Jung
authors.affiliation: Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science, Seoul National University, Seoul 151-741, South Korea; Brain Korea 21 Program for Leading Universities and Students (BK21 PLUS) Creative Veterinary Research Center, Seoul National University, Seoul 151-741, South Korea; and.
authors.forename: Eun Ju
authors.initials: EJ
authors.lastname: Song
authors.affiliation: Department of Agricultural Biotechnology, National Research Laboratory of Molecular Microbiology and Toxicology, and Center for Food Safety and Toxicology, Seoul National University, Seoul 151-921, South Korea.
authors.forename: Kyung Ku
authors.initials: KK
authors.lastname: Jang
authors.affiliation: Department of Agricultural Biotechnology, National Research Laboratory of Molecular Microbiology and Toxicology, and Center for Food Safety and Toxicology, Seoul National University, Seoul 151-921, South Korea.
authors.forename: Sang Ho
authors.initials: SH
authors.lastname: Choi
authors.affiliation: Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science, Seoul National University, Seoul 151-741, South Korea; Brain Korea 21 Program for Leading Universities and Students (BK21 PLUS) Creative Veterinary Research Center, Seoul National University, Seoul 151-741, South Korea; and hjhan@snu.ac.kr.
authors.forename: Ho Jae
authors.initials: HJ
authors.lastname: Han
mesh_terms: D000818:Animals; D017306:Annexin A2 / Q000235:genetics / Q000378:metabolism*; D017209:Apoptosis / Q000187:drug effects; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D015153:Blotting, Western; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D019175:DNA Methylation / Q000187:drug effects; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism* / Q000382:microbiology; D054884:Host-Pathogen Interactions; D006801:Humans; D053583:Interleukin-1beta / Q000096:biosynthesis* / Q000235:genetics; D007422:Intestines / Q000166:cytology; D021962:Membrane Microdomains / Q000378:metabolism; D008813:Mice, Inbred ICR; D018613:Microscopy, Confocal; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism*; D010196:Pancreatic Elastase / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D034622:RNA Interference; D017382:Reactive Oxygen Species / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects; D014735:Vibrio Infections / Q000235:genetics / Q000378:metabolism / Q000821:virology; D041261:Vibrio vulnificus / Q000235:genetics / Q000378:metabolism / Q000502:physiology
chemical_list: D017306:Annexin A2; D001426:Bacterial Proteins; D053583:Interleukin-1beta; D016328:NF-kappa B; D017382:Reactive Oxygen Species; D011994:Recombinant Proteins; D010196:Pancreatic Elastase