Role of Integrin β4 in Lung Endothelial Cell Inflammatory Responses to Mechanical Stress.

TitleRole of Integrin β4 in Lung Endothelial Cell Inflammatory Responses to Mechanical Stress.
Publication TypeJournal Article
Year of Publication2015
AuthorsChen W, Epshtein Y, Ni X, Dull RO, Cress AE, Garcia JGN, Jacobson JR
JournalSci Rep
Date Published2015 Nov 17
ISSN Number2045-2322
KeywordsAnimals, Bronchoalveolar Lavage Fluid, Cell Line, Cytokines, Disease Models, Animal, Endothelial Cells, Humans, Hydroxymethylglutaryl-CoA Reductase Inhibitors, Inflammation, Integrin beta4, Mice, Mice, Inbred C57BL, Mutagenesis, Site-Directed, Permeability, Phosphorylation, Protein Structure, Tertiary, Pulmonary Artery, Simvastatin, Stress, Mechanical, Ventilator-Induced Lung Injury

<p>Simvastatin, an HMG-CoA reductase inhibitor, has lung vascular-protective effects that are associated with decreased agonist-induced integrin β4 (ITGB4) tyrosine phosphorylation. Accordingly, we hypothesized that endothelial cell (EC) protection by simvastatin is dependent on these effects and sought to further characterize the functional role of ITGB4 as a mediator of EC protection in the setting of excessive mechanical stretch at levels relevant to ventilator-induced lung injury (VILI). Initially, early ITGB4 tyrosine phosphorylation was confirmed in human pulmonary artery EC subjected to excessive cyclic stretch (18% CS). EC overexpression of mutant ITGB4 with specific tyrosines mutated to phenylalanine (Y1440, Y1526 Y1640, or Y1422) resulted in significantly attenuated CS-induced cytokine expression (IL6, IL-8, MCP-1, and RANTES). In addition, EC overexpression of ITGB4 constructs with specific structural deletions also resulted in significantly attenuated CS-induced inflammatory cytokine expression compared to overexpression of wildtype ITGB4. Finally, mice expressing a mutant ITGB4 lacking a cytoplasmic signaling domain were found to have attenuated lung injury after VILI-challenge (VT = 40 ml/kg, 4 h). Our results provide mechanistic insights into the anti-inflammatory properties of statins and may ultimately lead to novel strategies targeted at ITGB4 signaling to treat VILI.</p>

Alternate JournalSci Rep
PubMed ID26572585
PubMed Central IDPMC4647208
Grant ListR01 HL096887 / HL / NHLBI NIH HHS / United States
HL096887 / HL / NHLBI NIH HHS / United States