Exercise training improves high-density lipoprotein-mediated transcription of proangiogenic microRNA in endothelial cells

The functional properties of endothelial cells (ECs) for regulating nitric oxide (NO) bioavailability are important for normal endothelial function. Micro-RNAs (miRs) and especially angiomiRs regulate vascular integrity and angiogenesis. Besides regulation of reverse cholesterol transport, high-density lipoprotein (HDL) also stimulates NO generation by ECs. This function is impaired in patients with chronic heart failure (CHF) and can be attenuated by exercise training. The aim of the present study was to evaluate if HDL-induced miR expression is altered in CHF and if exercise training has an impact.

HDL was isolated from CHF patients in NYHA-IIIb (HDL_NYHA) and healthy subjects (HDL_Healthy) before and after exercise training. Subsequently ECs were incubated for 24 h with the isolated HDL and miR expression was quantified by RT-PCR.

HDL-induced expression of miR-126, miR-21 and miR-222 was significantly reduced in ECs incubated with HDL_NYHA when compared to HDL_Healthy. Exercise training attenuated this HDL-induced reduction of miR-126 and miR-21. HDL-induced expression of miR-221 and miR-214 was not altered in CHF compared to controls and no impact of exercise training was noted.

In conclusion, the present study shows that HDL isolated from CHF patients (NYHA-III) reduces the expression of pro-angiogenic miRs (i.e. miR-126 and miR-21), which may contribute to atherogenesis and endothelial dysfunction. However, exercise training was able to attenuate the HDL-induced reduction in pro-angiogenic miRs expression.