title: High tidal volume ventilation induces proinflammatory signaling in rat lung endothelium.
abstract: Alveolar overdistension during mechanical ventilation causes leukocyte sequestration, leading to lung injury. However, underlying endothelial cell (EC) mechanisms are undefined. In a new approach, we exposed isolated blood-perfused rat lungs to high tidal volume ventilation (HV) for 2 h, then obtained fresh lung endothelial cells (FLEC) by immunosorting at 4 degrees C. Immunoblotting experiments indicated that as compared with FLEC derived from lungs ventilated at low volume (LV), HV markedly enhanced tyrosine phosphorylation (TyrP). The tyrosine kinase blocker, genistein, inhibited this response. HV also induced focal adhesion (FA) formation in FLEC, as detected by immunofluorescent aggregates of the alpha(v)beta(3) integrin that co-localized with aggregations of focal adhesion kinase (FAK). Immunoprecipitation and blotting experiments revealed that HV increased TyrP of the FA protein, paxillin. In addition, HV induced a paxillin-associated P-selectin expression on FLEC that was also inhibited by genistein. However, HV did not increase lung water. These results indicate that in HV, EC signaling in situ causes FA formation and induces TyrP-dependent P-selectin expression. These signaling mechanisms may promote leukocyte-mediated responses in HV.
authors.affiliation: Department of Pediatrics, College of Physicians and Surgeons, Columbia University, New York, NY, USA. sb80@columbia.edu
authors.forename: Sunita
authors.initials: S
authors.lastname: Bhattacharya
authors.forename: Namita
authors.initials: N
authors.lastname: Sen
authors.forename: Maimaiti T
authors.initials: MT
authors.lastname: Yiming
authors.forename: Rashmi
authors.initials: R
authors.lastname: Patel
authors.forename: Kaushik
authors.initials: K
authors.lastname: Parthasarathi
authors.forename: Sadiqa
authors.initials: S
authors.lastname: Quadri
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Issekutz
authors.forename: Jahar
authors.initials: J
authors.lastname: Bhattacharya
mesh_terms: D000818:Animals; D003598:Cytoskeletal Proteins / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology / Q000502:physiology; D022001:Focal Adhesions; D066298:In Vitro Techniques; D007249:Inflammation / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D018836:Inflammation Mediators / Q000378:metabolism; D008168:Lung / Q000098:blood supply* / Q000502:physiology*; D019007:P-Selectin / Q000378:metabolism; D051419:Paxillin; D010477:Perfusion; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction; D013990:Tidal Volume / Q000502:physiology*; D014443:Tyrosine / Q000378:metabolism
chemical_list: D003598:Cytoskeletal Proteins; D018836:Inflammation Mediators; D019007:P-Selectin; D051419:Paxillin; D010750:Phosphoproteins; C496063:Pxn protein, rat; D014443:Tyrosine