Intrapleural Adenoviral Delivery of Human PAI-1 Exacerbates TCN-Induced Pleural Injury in Rabbits.

Karandashova S, Florova G, Azghani AO, Komissarov AA, Koenig K, Tucker TA, Allen TC, Stewart K, Tvinnereim A, Idell S.

Source

The Texas Lung Injury Institute of The University of Texas Health Science Center at Tyler, Tyler, Texas, United States.

Abstract

Elevated levels of plasminogen activator inhibitor 1 (PAI-1) are associated with pleural injury but its effects on pleural organization remain unclear. A method of adenovirus-mediated delivery of genes of interest, expressed under a cytomegalovirus promoter, to the rabbit pleura was developed and used with lacZ and human (h) PAI-1. Histology, β-galactosidase staining, Western blot, enzymatic and immunohistochemical analyses of pleural fluids (PFs), lavages, and pleural mesothelial cells were used to evaluate the efficiency and effects of transduction. Transduction was selective and limited to the pleural mesothelial monolayer. Intrapleural expression of both genes was transient, with peak expression at 4-5 days. At day 5, hPAI-1 (40-80 and 200-400 nM of active and total hPAI-1 in lavages, respectively) caused no overt pleural injury, effusions or fibrosis. Adenovirus-mediated delivery of hPAI-1 with subsequent tetracycline-induced pleural injury resulted in a significant exacerbation of the pleural fibrosis observed at day 5 (P=0.029 and 0.021 versus vehicle and adenoviral controls, respectively). Intrapleural fibrinolytic therapy (IPFT) with plasminogen activators was effective in both animals overexpressing hPAI-1 and controls with tetracycline-injury alone. An increase in intrapleural active PAI-1 (from 10-15 in controls to 20-40 nM in hPAI-1 overexpressing animals) resulted in increased formation of PAI-1/plasminogen activator complexes in vivo. The decrease in intrapleural plasminogen-activating activity observed at 10-40 min after IPFT correlates linearly with the initial level of active PAI-1. Therefore, active PAI-1 in PFs affects the outcome of IPFT, and may be both a biomarker of pleural injury and a molecular target for its treatment.

TimAllenMDJD

Tuesday, September 25, 2012