title: Hypoxia-induced changes in protein s-nitrosylation in female mouse brainstem.
abstract: Exposure to hypoxia elicits an increase in minute ventilation that diminishes during continued exposure (roll-off). Brainstem N-methyl-D-aspartate receptors (NMDARs) and neuronal nitric oxide synthase (nNOS) contribute to the initial hypoxia-induced increases in minute ventilation. Roll-off is regulated by platelet-derived growth factor receptor-β (PDGFR-β) and S-nitrosoglutathione (GSNO) reductase (GSNOR). S-nitrosylation inhibits activities of NMDAR and nNOS, but enhances GSNOR activity. The importance of S-nitrosylation in the hypoxic ventilatory response is unknown. This study confirms that ventilatory roll-off is virtually absent in female GSNOR(+/-) and GSNO(-/-) mice, and evaluated the location of GSNOR in female mouse brainstem, and temporal changes in GSNOR activity, protein expression, and S-nitrosylation status of GSNOR, NMDAR (1, 2A, 2B), nNOS, and PDGFR-β during hypoxic challenge. GSNOR-positive neurons were present throughout the brainstem, including the nucleus tractus solitarius. Protein abundances for GSNOR, nNOS, all NMDAR subunits and PDGFR-β were not altered by hypoxia. GSNOR activity and S-nitrosylation status temporally increased with hypoxia. In addition, nNOS S-nitrosylation increased with 3 and 15 minutes of hypoxia. Changes in NMDAR S-nitrosylation were detected in NMDAR 2B at 15 minutes of hypoxia. No hypoxia-induced changes in PDGFR-β S-nitrosylation were detected. However, PDGFR-β phosphorylation increased in the brainstems of wild-type mice during hypoxic exposure (consistent with roll-off), whereas it did not rise in GSNOR(+/-) mice (consistent with lack of roll-off). These data suggest that: (1) S-nitrosylation events regulate hypoxic ventilatory response; (2) increases in S-nitrosylation of NMDAR 2B, nNOS, and GSNOR may contribute to ventilatory roll-off; and (3) GSNOR regulates PDGFR-β phosphorylation.
authors.affiliation: 1 Department of Pediatrics, University of Virginia School of Medicine, Charlottesville, Virginia.
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Palmer
authors.lastname: Kimberly deRonde
authors.forename: Kathleen
authors.initials: K
authors.lastname: Brown-Steinke
authors.forename: Sonya
authors.initials: S
authors.lastname: Gunter
authors.forename: Vinod
authors.initials: V
authors.lastname: Jyothikumar
authors.forename: Michael S
authors.initials: MS
authors.lastname: Forbes
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Lewis
mesh_terms: D000426:Alcohol Dehydrogenase; D000818:Animals; D001933:Brain Stem / Q000378:metabolism* / Q000473:pathology; D005260:Female; D005980:Glutathione Reductase / Q000235:genetics / Q000378:metabolism; D000860:Hypoxia / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D018345:Mice, Knockout; D009474:Neurons / Q000378:metabolism* / Q000473:pathology; D052248:Nitric Oxide Synthase Type I / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation / Q000235:genetics; D011499:Protein Processing, Post-Translational; D020797:Receptor, Platelet-Derived Growth Factor beta / Q000235:genetics / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000235:genetics / Q000378:metabolism; D026422:S-Nitrosoglutathione / Q000378:metabolism*
chemical_list: D016194:Receptors, N-Methyl-D-Aspartate; D026422:S-Nitrosoglutathione; C483598:Adh5 protein, mouse; D000426:Alcohol Dehydrogenase; D052248:Nitric Oxide Synthase Type I; C496321:Nos1 protein, mouse; D005980:Glutathione Reductase; D020797:Receptor, Platelet-Derived Growth Factor beta
keywords: N-methyl-D-aspartate receptor; S-nitrosoglutathione reductase; hypoxic ventilatory response; neuronal nitric oxide synthase; platelet-derived growth factor receptor-β