title: NADPH Oxidase-Derived Peroxynitrite Drives Inflammation in Mice and Human Nonalcoholic Steatohepatitis via TLR4-Lipid Raft Recruitment.
abstract: The molecular events that link NADPH oxidase activation and the induction of Toll-like receptor (TLR)-4 recruitment into hepatic lipid rafts in nonalcoholic steatohepatitis (NASH) are unclear. We hypothesized that in liver, NADPH oxidase activation is key in TLR4 recruitment into lipid rafts, which in turn up-regulates NF-κB translocation to the nucleus and subsequent DNA binding, leading to NASH progression. Results from confocal microscopy showed that liver from murine and human NASH had NADPH oxidase activation, which led to the formation of highly reactive peroxynitrite, as shown by 3-nitrotyrosine formation in diseased liver. Expression and recruitment of TLR4 into the lipid rafts were significantly greater in rodent and human NASH. The described phenomenon was NADPH oxidase, p47phox, and peroxynitrite dependent, as liver from p47phox-deficient mice and from mice treated with a peroxynitrite decomposition catalyst [iron(III) tetrakis(p-sulfonatophenyl)porphyrin] or a peroxynitrite scavenger (phenylboronic acid) had markedly less Tlr4 recruitment into lipid rafts. Mechanistically, peroxynitrite-induced TLR4 recruitment was linked to increased IL-1β, sinusoidal injury, and Kupffer cell activation while blocking peroxynitrite-attenuated NASH symptoms. The results strongly suggest that NADPH oxidase-mediated peroxynitrite drove TLR4 recruitment into hepatic lipid rafts and inflammation, whereas the in vivo use of the peroxynitrite scavenger phenylboronic acid, a novel synthetic molecule having high reactivity with peroxynitrite, attenuates inflammatory pathogenesis in NASH.
authors.affiliation: Environmental Health and Disease Laboratory, Department of Environmental Health Sciences, University of South Carolina, Columbia, South Carolina.
authors.forename: Suvarthi
authors.initials: S
authors.lastname: Das
authors.affiliation: Environmental Health and Disease Laboratory, Department of Environmental Health Sciences, University of South Carolina, Columbia, South Carolina.
authors.forename: Firas
authors.initials: F
authors.lastname: Alhasson
authors.affiliation: Environmental Health and Disease Laboratory, Department of Environmental Health Sciences, University of South Carolina, Columbia, South Carolina.
authors.forename: Diptadip
authors.initials: D
authors.lastname: Dattaroy
authors.affiliation: Environmental Health and Disease Laboratory, Department of Environmental Health Sciences, University of South Carolina, Columbia, South Carolina.
authors.forename: Sahar
authors.initials: S
authors.lastname: Pourhoseini
authors.affiliation: Environmental Health and Disease Laboratory, Department of Environmental Health Sciences, University of South Carolina, Columbia, South Carolina.
authors.forename: Ratanesh Kumar
authors.initials: RK
authors.lastname: Seth
authors.affiliation: Department of Pathology, Microbiology and Immunology, University of South Carolina, Columbia, South Carolina.
authors.forename: Mitzi
authors.initials: M
authors.lastname: Nagarkatti
authors.affiliation: Department of Pathology, Microbiology and Immunology, University of South Carolina, Columbia, South Carolina.
authors.forename: Prakash S
authors.initials: PS
authors.lastname: Nagarkatti
authors.affiliation: Division of Gastroenterology, Department of Medicine, Duke University, Durham, North Carolina.
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Michelotti
authors.affiliation: Division of Gastroenterology, Department of Medicine, Duke University, Durham, North Carolina.
authors.forename: Anna Mae
authors.initials: AM
authors.lastname: Diehl
authors.affiliation: Department of Biophysics, Free Radical Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin.
authors.forename: Balaraman
authors.initials: B
authors.lastname: Kalyanaraman
authors.affiliation: Environmental Health and Disease Laboratory, Department of Environmental Health Sciences, University of South Carolina, Columbia, South Carolina. Electronic address: schatt@mailbox.sc.edu.
authors.forename: Saurabh
authors.initials: S
authors.lastname: Chatterjee
mesh_terms: D000818:Animals; D001897:Boronic Acids / Q000494:pharmacology; D006801:Humans; D007249:Inflammation / Q000188:drug therapy / Q000473:pathology; D008099:Liver / Q000293:injuries / Q000378:metabolism / Q000473:pathology; D008297:Male; D021962:Membrane Microdomains / Q000378:metabolism / Q000473:pathology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008820:Mice, Obese; D008822:Mice, Transgenic; D019255:NADPH Oxidases / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism; D065626:Non-alcoholic Fatty Liver Disease / Q000201:enzymology / Q000473:pathology*; D030421:Peroxynitrous Acid / Q000378:metabolism*; D015398:Signal Transduction; D013047:Specific Pathogen-Free Organisms; D051197:Toll-Like Receptor 4 / Q000235:genetics / Q000378:metabolism*; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism
chemical_list: D001897:Boronic Acids; D016328:NF-kappa B; C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4; D030421:Peroxynitrous Acid; C002744:3-nitrotyrosine; D014443:Tyrosine; D019255:NADPH Oxidases; C010686:benzeneboronic acid