RESUMO
Acute lung injury (ALI) is characterized by endothelial barrier disruption resulting in increased vascular permeability. As focal adhesion kinase (FAK), a non-receptor protein tyrosine kinase, is involved in endothelial cell (EC) barrier regulation, we hypothesized that FAK inhibition could attenuate agonist-induced EC barrier disruption relevant to ALI. Human lung EC were pretreated with one of three pharmacologic FAK inhibitors, PF-573,228 (PF-228, 10⯵M), PF-562,271 (PF-271, 5⯵M) or NVP-TAE226 (TAE226, 5⯵M) for 30â¯min prior to treatment with thrombin (1â¯U/ml, 30â¯min). Western blotting confirmed attenuated thrombin-induced FAK phosphorylation associated with all three inhibitors. Subsequently, EC were pretreated with either PF-228 (10⯵M), TAE226 (5⯵M) or PF-271 (5⯵M) for 30â¯min prior to thrombin stimulation (1â¯U/ml) followed by measurements of barrier integrity by transendothelial electrical resistance (TER). Separately, EC grown in transwell inserts prior to thrombin (1â¯U/ml) with measurements of FITC-dextran flux after 30â¯min confirmed a significant attenuation of thrombin-induced EC barrier disruption by PF-228 alone. Finally, in a murine ALI model induced by LPS (1.25â¯mg/ml, IT), rescue treatment with PF-228 was associated with significantly reduced lung injury. Our findings PF-228, currently being studied in clinical trials, may serve as a novel and effective therapeutic agent for ALI.