| First Author | Schmidt TT | Year | 2013 |
| Journal | Am J Physiol Lung Cell Mol Physiol | Volume | 305 |
| Issue | 4 | Pages | L291-300 |
| PubMed ID | 23771883 | Mgi Jnum | J:231253 |
| Mgi Id | MGI:5770043 | Doi | 10.1152/ajplung.00094.2013 |
| Citation | Schmidt TT, et al. (2013) Conditional deletion of FAK in mice endothelium disrupts lung vascular barrier function due to destabilization of RhoA and Rac1 activities. Am J Physiol Lung Cell Mol Physiol 305(4):L291-300 |
| abstractText | Loss of lung-fluid homeostasis is the hallmark of acute lung injury (ALI). Association of catenins and actin cytoskeleton with vascular endothelial (VE)-cadherin is generally considered the main mechanism for stabilizing adherens junctions (AJs), thereby preventing disruption of lung vascular barrier function. The present study identifies endothelial focal adhesion kinase (FAK), a nonreceptor tyrosine kinase that canonically regulates focal adhesion turnover, as a novel AJ-stabilizing mechanism. In wild-type mice, induction of ALI by intraperitoneal administration of lipopolysaccharide or cecal ligation and puncture markedly decreased FAK expression in lungs. Using a mouse model in which FAK was conditionally deleted only in endothelial cells (ECs), we show that loss of EC-FAK mimicked key features of ALI (diffuse lung hemorrhage, increased transvascular albumin influx, edema, and neutrophil accumulation in the lung). EC-FAK deletion disrupted AJs due to impairment of the fine balance between the activities of RhoA and Rac1 GTPases. Deletion of EC-FAK facilitated RhoA's interaction with p115-RhoA guanine exchange factor, leading to activation of RhoA. Activated RhoA antagonized Rac1 activity, destabilizing AJs. Inhibition of Rho kinase, a downstream effector of RhoA, reinstated normal endothelial barrier function in FAK-/- ECs and lung vascular integrity in EC-FAK-/- mice. Our findings demonstrate that EC-FAK plays an essential role in maintaining AJs and thereby lung vascular barrier function by establishing the normal balance between RhoA and Rac1 activities. |
