title: Nitric oxide synthase-2 regulates mitochondrial Hsp60 chaperone function during bacterial peritonitis in mice.
abstract: Nitric oxide synthase-2 (NOS2) plays a critical role in reactive nitrogen species generation and cysteine modifications that influence mitochondrial function and signaling during inflammation. Here, we investigated the role of NOS2 in hepatic mitochondrial biogenesis during Escherichia coli peritonitis in mice. NOS2(-/-) mice displayed smaller mitochondrial biogenesis responses than Wt mice during E. coli infection according to differences in mRNA levels for the PGC-1 alpha coactivator, nuclear respiratory factor-1, mitochondrial transcription factor-A (Tfam), and mtDNA polymerase (Pol gamma). NOS2(-/-) mice did not significantly increase mitochondrial Tfam and Pol gamma protein levels during infection in conjunction with impaired mitochondrial DNA (mtDNA) transcription, loss of mtDNA copy number, and lower State 3 respiration rates. NOS2 blockade in mitochondrial-GFP reporter mice disrupted Hsp60 localization to mitochondria after E. coli exposure. Mechanistically, biotin-switch and immunoprecipitation studies demonstrated NOS2 binding to and S-nitros(yl)ation of Hsp60 and Hsp70. Specifically, NOS2 promoted Tfam accumulation in mitochondria by regulation of Hsp60-Tfam binding via S-nitros(yl)ation. In hepatocytes, site-directed mutagenesis identified (237)Cys as a critical residue for Hsp60 S-nitros(yl)ation. Thus, the role of NOS2 in inflammation-induced mitochondrial biogenesis involves both optimal gene expression for nuclear-encoded mtDNA-binding proteins and functional regulation of the Hsp60 chaperone that enables their importation for mtDNA transcription and replication.
authors.affiliation: Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: Hagir B
authors.initials: HB
authors.lastname: Suliman
authors.forename: Abdelwahid
authors.initials: A
authors.lastname: Babiker
authors.forename: Crystal M
authors.initials: CM
authors.lastname: Withers
authors.forename: Timothy E
authors.initials: TE
authors.lastname: Sweeney
authors.forename: Martha S
authors.initials: MS
authors.lastname: Carraway
authors.forename: Lynn G
authors.initials: LG
authors.lastname: Tatro
authors.forename: Raquel R
authors.initials: RR
authors.lastname: Bartz
authors.forename: Karen E
authors.initials: KE
authors.lastname: Welty-Wolf
authors.forename: Claude A
authors.initials: CA
authors.lastname: Piantadosi
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D018834:Chaperonin 60 / Q000235:genetics / Q000378:metabolism*; D004272:DNA, Mitochondrial / Q000235:genetics; D004268:DNA-Binding Proteins / Q000378:metabolism; D004259:DNA-Directed DNA Polymerase / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000276:immunology* / Q000472:pathogenicity; D004927:Escherichia coli Infections / Q000150:complications / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D022781:Hepatocytes / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008930:Mitochondria, Liver / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000378:metabolism; D016297:Mutagenesis, Site-Directed; D052247:Nitric Oxide Synthase Type II / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D051266:Nuclear Respiratory Factor 1 / Q000378:metabolism; D010538:Peritonitis / Q000209:etiology / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D011485:Protein Binding / Q000235:genetics; D021381:Protein Transport / Q000235:genetics; D056152:Respiratory Rate / Q000235:genetics; D015534:Trans-Activators / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D018834:Chaperonin 60; D004272:DNA, Mitochondrial; D004268:DNA-Binding Proteins; D024101:Mitochondrial Proteins; C495634:Nrf1 protein, mouse; D051266:Nuclear Respiratory Factor 1; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; C485290:Ppargc1a protein, mouse; D015534:Trans-Activators; D014157:Transcription Factors; C422562:mitochondrial transcription factor A; D052247:Nitric Oxide Synthase Type II; D004259:DNA-Directed DNA Polymerase