title: PPARγ ligands regulate NADPH oxidase, eNOS, and barrier function in the lung following chronic alcohol ingestion.
abstract: BACKGROUND
  Chronic alcohol ingestion increases the incidence and severity of the acute respiratory distress syndrome (ARDS), where reactive species contribute to alveolar-capillary barrier dysfunction and noncardiogenic pulmonary edema. Previous studies demonstrated that chronic alcohol ingestion increased lung NADPH oxidase and endothelial nitric oxide synthase (eNOS) expression and that ligands for the peroxisome proliferator-activated receptor gamma (PPARγ) reduced NADPH oxidase expression. Therefore, we hypothesized that the PPARγ ligand, rosiglitazone, would attenuate alcohol-induced NADPH oxidase expression and pulmonary barrier dysfunction.
  
  
  METHODS
  C57Bl/6 mice were treated ± alcohol in drinking water (20% w/v) for 12 weeks. During the final week of alcohol treatment, mice were gavaged with rosiglitazone (10 mg/kg/d) or vehicle. Selected animals were treated twice with lipopolysaccharide (LPS, 2 mg/kg IP) prior to sacrifice. Pulmonary barrier dysfunction was estimated from protein content of bronchoalveolar lavage (BAL) fluid.
  
  
  RESULTS
  LPS treatment increased BAL protein in alcohol-fed but not control mice, and rosiglitazone attenuated LPS and alcohol-induced pulmonary barrier dysfunction. Alcohol- and LPS-induced increases in lung eNOS, Nox1, and Nox4 expression were attenuated by rosiglitazone. In vitro, alcohol (0.10% w/v) increased H(2)O(2) production, barrier dysfunction, eNOS, Nox1, and Nox4 expression in human umbilical vein endothelial cell (HUVEC) monolayers, effects also attenuated by rosiglitazone (10 μM). Alcohol-induced HUVEC barrier dysfunction was attenuated by inhibition of NOS or addition of the eNOS cofactor, tetrahydrobiopterin.
  
  
  CONCLUSIONS
  These results indicate that PPARγ activation reduced expression of eNOS, Nox1, Nox4, the production of reactive species, and barrier dysfunction caused by chronic alcohol ingestion and suggest that PPARγ represents a novel therapeutic target for strategies designed to reduce the risk of lung injury in patients with a history of chronic alcohol ingestion.
authors.affiliation: Department of Medicine, Atlanta Veterans' Affairs and Emory University Medical Centers, Decatur, Georgia, USA.
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Wagner
authors.forename: Samantha M
authors.initials: SM
authors.lastname: Yeligar
authors.forename: Lou Ann
authors.initials: LA
authors.lastname: Brown
authors.forename: C
authors.initials: C
authors.lastname: Michael Hart
mesh_terms: D000818:Animals; D015824:Blood-Air Barrier / Q000187:drug effects*; D015153:Blotting, Western; D002478:Cells, Cultured; D002492:Central Nervous System Depressants / Q000494:pharmacology*; D000431:Ethanol / Q000494:pharmacology*; D005260:Female; D061307:Human Umbilical Vein Endothelial Cells / Q000187:drug effects; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D007004:Hypoglycemic Agents / Q000494:pharmacology; D008024:Ligands; D008070:Lipopolysaccharides / Q000494:pharmacology; D008168:Lung / Q000187:drug effects*; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism; D000074624:NADPH Oxidase 1; D000074662:NADPH Oxidase 2; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism*; D047495:PPAR gamma / Q000187:drug effects*; D060888:Real-Time Polymerase Chain Reaction; D000077154:Rosiglitazone; D045162:Thiazolidinediones / Q000494:pharmacology
chemical_list: D002492:Central Nervous System Depressants; D007004:Hypoglycemic Agents; D008024:Ligands; D008070:Lipopolysaccharides; D008562:Membrane Glycoproteins; D047495:PPAR gamma; D045162:Thiazolidinediones; D000077154:Rosiglitazone; D000431:Ethanol; D006861:Hydrogen Peroxide; C496314:NOS3 protein, human; D052250:Nitric Oxide Synthase Type III; D009247:NADH, NADPH Oxidoreductases; C488842:Cybb protein, mouse; D000074624:NADPH Oxidase 1; D000074662:NADPH Oxidase 2; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases; C000614711:NOX1 protein, mouse; C422943:Nox4 protein, mouse