Rationale: High-density lipoprotein (HDL) exerts endothelial-protective effects via stimulation of endothelial cell (EC) nitric oxide (NO) production. This function is impaired in patients with cardiovascular disease. Protective effects of exercise training (ET) on endothelial function have been demonstrated.
Objective: This study was performed to evaluate the impact of ET on HDL-mediated protective effects and the respective molecular pathways in patients with chronic heart failure (CHF).
Methods and results: HDL was isolated from 16 healthy controls (HDL(healthy)) and 16 patients with CHF-NYHA-III (HDL(NYHA-IIIb)) before and after ET, as well as from 8 patients with CHF-NYHA-II (HDL(NYHA-II)). ECs were incubated with HDL, and phosphorylation of eNOS-Ser(1177), eNOS-Thr(495), PKC-βII-Ser(660), and p70S6K-Ser(411) was evaluated. HDL-bound malondialdehyde and HDL-induced NO production by EC were quantified. Endothelial function was assessed by flow-mediated dilatation. The proteome of HDL particles was profiled by shotgun LC-MS/MS. Incubation of EC with HDL(NYHA-IIIb) triggered a lower stimulation of phosphorylation at eNOS-Ser(1177) and a higher phosphorylation at eNOS-Thr(495) when compared with HDL(healthy). This was associated with lower NO production of EC. In addition, an elevated activation of p70S6K, PKC-βII by HDL(NYHA-IIIb), and a higher amount of malondialdehyde bound to HDL(NYHA-IIIb) compared with HDL(healthy) was measured. In healthy individuals, ET had no effect on HDL function, whereas ET of CHF-NYHA-IIIb significantly improved HDL function. A correlation between changes in HDL-induced NO production and flow-mediated dilatation improvement by ET was evident.
Conclusions: These results demonstrate that HDL function is impaired in CHF and that ET improved the HDL-mediated vascular effects. This may be one mechanism how ET exerts beneficial effects in CHF.
Keywords: aerobic exercise; eNOS; lipoproteins, HDL.