title: Role of Integrin β4 in Lung Endothelial Cell Inflammatory Responses to Mechanical Stress.
abstract: 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.
authors.affiliation: Division of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois at Chicago, Chicago, IL.
authors.forename: Weiguo
authors.initials: W
authors.lastname: Chen
authors.affiliation: Division of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois at Chicago, Chicago, IL.
authors.forename: Yulia
authors.initials: Y
authors.lastname: Epshtein
authors.affiliation: Department of Anatomy, Harbin Medical University at Daqing, China.
authors.forename: Xiuquin
authors.initials: X
authors.lastname: Ni
authors.affiliation: Department of Anesthesiology, University of Illinois at Chicago, Chicago, IL.
authors.forename: Randal O
authors.initials: RO
authors.lastname: Dull
authors.affiliation: Department of Medicine, University of Arizona, Tucson, AZ.
authors.forename: Anne E
authors.initials: AE
authors.lastname: Cress
authors.affiliation: Department of Medicine, University of Arizona, Tucson, AZ.
authors.forename: Joe G N
authors.initials: JG
authors.lastname: Garcia
authors.affiliation: Division of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois at Chicago, Chicago, IL.
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Jacobson
mesh_terms: D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D002460:Cell Line; D016207:Cytokines / Q000378:metabolism; D004195:Disease Models, Animal; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000494:pharmacology / Q000627:therapeutic use; D007249:Inflammation / Q000517:prevention & control; D039663:Integrin beta4 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D016297:Mutagenesis, Site-Directed; D010539:Permeability / Q000187:drug effects; D010766:Phosphorylation; D017434:Protein Structure, Tertiary; D011651:Pulmonary Artery / Q000166:cytology; D019821:Simvastatin / Q000494:pharmacology / Q000627:therapeutic use; D013314:Stress, Mechanical; D055397:Ventilator-Induced Lung Injury / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control
chemical_list: D016207:Cytokines; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D039663:Integrin beta4; D019821:Simvastatin