High tidal volume mechanical ventilation with hyperoxia alters alveolar type II cell adhesion

Leena P. Desai, Scott E. Sinclair, Kenneth E. Chapman, Aviv Hassid, Christopher M. Waters

Research output: Contribution to journalArticlepeer-review

37 Scopus citations

Abstract

Patients with acute respiratory distress syndrome undergoing mechanical ventilation may be exposed to both high levels of stretch and high levels of oxygen. We hypothesized that the combination of high stretch and hyperoxia promotes loss of epithelial adhesion and impairs epithelial repair mechanisms necessary for restoration of barrier function. We utilized a model of high tidal volume mechanical ventilation (25 ml/kg) with hyperoxia (50% O2) in rats to investigate alveolar type II (AT2) cell adhesion and focal adhesion signaling. AT2 cells isolated from rats exposed to hyperoxia and high tidal volume mechanical ventilation (MVHO) exhibited significantly decreased cell adhesion and reduction in phosphotyrosyl levels of focal adhesion kinase (FAK) and paxillin compared with control rats, rats exposed to hyperoxia without ventilation (HO), or rats ventilated with normoxia (MV). MV alone increased phosphorylation of p130Cas. RhoA activation was increased by MV, HO, and the combination of MV and HO. Treatment of MVHO cells with keratinocyte growth factor (KGF) for 1 h upon isolation reduced RhoA activity and restored attachment to control levels. Attachment and migration of control AT2 cells was significantly decreased by constitutively active RhoA or a kinase inactive form of FAK (FRNK), whereas expression of dominant negative RhoA in cells from MVHO-treated rats restored cell adhesion. Mechanical ventilation with hyperoxia promotes changes in focal adhesion proteins and RhoA in AT2 cells that may be deleterious for cell adhesion and migration.

Original languageEnglish
Pages (from-to)L769-L778
JournalAmerican Journal of Physiology - Lung Cellular and Molecular Physiology
Volume293
Issue number3
DOIs
StatePublished - Sep 2007

Keywords

  • Focal adhesion kinase
  • Keratinocyte growth factor
  • RhoA

ASJC Scopus subject areas

  • Physiology
  • Pulmonary and Respiratory Medicine
  • Physiology (medical)
  • Cell Biology

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