Abstract 494: Rho-a Kinase Activation in Endothelial Cells is Induced by Cocaine or Plasma From Cocaine Consumers: Association With a Prothrombotic Phenotype and Effect of the Inhibitors Atorvastatin and Y-27632

Abstract

Cocaine consumption is associated with increased risk of cardio- and cerebrovascular diseases, which are the consequence of endothelial dysfunction (ED). We recently showed that cocaine use is related to increased ED markers including circulating endothelial cells, although the mechanisms governing ED in cocaine users are still being researched. Since the RhoA/Rho kinase (ROCK) pathway is involved in the pathogenesis of ED, our Aim was to study in vitro and ex vivo RhoA/Rho kinase activation and ED markers in relation to cocaine consumption. Method Plasma samples from active cocaine consumers who met DSM-IV criteria and age and gender-matched controls were tested. ROCK activity, von Willebrand factor (vWf), Metalloproteases (MMP) and platelet adhesion were evaluated in HUVEC supplemented with cocaine (10μM), 10% plasma from cocaine users (CP), normal plasma (NP) or vehicle, in the presence or absence of Y-27632 (10 μM) and atorvastatin (ATS:10μM). Results CP induced higher ROCK (p: 0.039) and MMP 2 activity (p<0.05) in HUVEC, released significantly elevated vWf (p0.001), but failed to stimulate MMP activity or vWf release. ATS and Y-27632 significantly reduced ROCK activity (p<0.01 and p<0.001) and platelet adhesion (p< 0.0001 and p: 0.0073) in CP treated cells. ATS also reduced MMP2 activity (p< 0.001) and vWf release (p: 0.004). In cocaine treated cells, ATS and Y-27632 downregulated ROCK activity (p: 0.039 and p: 0.091) and significantly reduced platelet adhesion (p: 0.0156 and p: 0.073). Ex vivo studies showed significantly higher ROCK (p 0.015), MMP-2 (p<0.05) and MMP-9 (p<0.01) activity in cocaine consumers than in controls. Conclusions Cocaine and cocaine consumer plasma increased ROCK activity in HUVEC, resembling the ex vivo findings. Only CP induced higher MMP activity and release of vWf resembling the findings in patients. The significant reduction of most of the in vitro effects by ATS and Y-27632 may provide a novel and potential therapeutic tool for the protection of the endothelium from deleterious stimuli such as cocaine consumption.