Circulating microparticles from acute coronary syndrome patients complicated with type 2 diabetes induce endothelial cell injury in rats

Objective To investigate the effects of circulating microparticulates (MPs) on vascular endothelium injury in patients with acute coronary syndrome (ACS) and type 2 diabetes (T2DM). Methods MPs were extracted from control (n=15), ACS patients (ACS, n=18), T2DM patients (T2DM, n=18) and ACS patients with T2DM (ACS+T2DM group, n=18). After incubation of rat thoracic artery tissue with MPs, the effects of MPs on endothelial dependent vasodilatation was detected with biological assay, expression of caveolin-1, coupling of endothelial nitric oxide synthase (eNOS) with heat shock protein 90 (Hsp90) was detected with Western blot. The changes in nitric oxide (NO) and superoxide anion were examined with chemical assay. Results The MPs concentration in ACS+T2DM patients samples was higher than that in control (P＜0.05). However, compared with ACS and T2DM patients, there was no statistically significant difference in MPs concentration. Compared with the control, regardless of ACS, T2DM and ACS+T2DM, their MPs inhibited endothelial dependent vasodilatation function, eNOS and Hsp90 coupling and NO production and stimulated expression of caveolin-1 and generation(P＜0.05). However, compared with ACS and T2DM patients, the effects of MPs were stronger in ACS+T2DM(P＜0.05). Conclusions The changes in the quality (or function) of MPs in ACS+T2DM lead to damage of rat vascular endothelium by MPs. MPs are potential marker molecules to support diagnosis of endothelial dysfunction.