Combinatorial treatment with epigenetic modifiers inhibits thrombin‐induced eNOS/RhoA signaling and restores AJ integrity (1176.7)

Abstract

Objective: Treatment of acute lung injury (ALI) is to target the pathways that lead to profound dysregulation of the restrictive endothelial barrier, and thereby restore lung microvascular endothelial barrier function and inhibit protein‐rich tissue fluid accumulation. Here we test the hypothesis that epigenetic modifiers TSA (Trichostatin‐A, HDAC inhibitor) and Aza (5‐aza‐2‐deoxycytidine, DNA methyl transferase inhibitor) together inhibit the thrombin induced eNOS/RhoA signaling and restore adherens junctions (AJs) integrity and diminished endothelial hyperpermeability.Results: The signaling, AJ integrity and endothelial permeability were assessed by RT‐PCR, immunofluoresence, Western analysis, and transendothelial resistance (TER). Our data show that combination of TSA+Aza is more effective in inhibiting thrombin‐induced lung hyperpermeability. We used an in vitro culture system of TER to determine the effect of TSA+Aza on thrombin‐induced change in resistance over the human pulmonary arterial endothelial cells. TSA+Aza treatment ameliorated the thrombin‐induced endothelial barrier disruption. The Western analysis data show that the treatment of TSA+Aza decreases the levels of thrombin induced RhoA and eNos signaling in lung endothelial cells.Conclusions: Our data indicate, for the first time, that TSA+Aza exert a protective role in preventing lung microvascular hyperpermeability and endothelial barrier disruption in thrombin‐induced lung injury, and thus have great potential as novel therapeutic agents