High tidal volume ventilation induces proinflammatory signaling in rat lung endothelium

S Bhattacharya, N Sen, MT Yiming, R Patel… - American journal of …, 2003 - atsjournals.org
S Bhattacharya, N Sen, MT Yiming, R Patel, K Parthasarathi, S Quadri, AC Issekutz…
American journal of respiratory cell and molecular biology, 2003atsjournals.org
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° C. Immunoblotting experiments indicated that as compared with FLEC
derived from lungs ventilated at low volume (LV), HV markedly enhanced tyrosine …
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°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 αvβ3 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.
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