Endothelial cell growth response to stimulation with serum from patients with acute ST-elevation myocardial infarction

Association of endothelial proliferation with the magnitude of weight loss during calorie restriction

OBJECTIVES

Substantial weight loss through intense dietary regimens is thought to ameliorate endothelial dysfunction in obesity. It is less clear whether similar improvements can be achieved with modest dietary interventions. This study aimed to identify the parameters of endothelial cell status in obesity that are affected by mild calorie restriction.

METHODS

Human umbilical vein endothelial cells (EA.hy926 line) in culture were exposed pairwise to serum from 57 individuals with simple obesity (BMI > 30 kg/m(2)) collected before and after 8-week dietary intervention with energy deficit of 300-500 kcal/day.

RESULTS

Analysis of endothelial transcriptome suggested that the intervention could impact on endothelial cell growth. Cell proliferation was measured with the MTT test and verified by [(3)H]-thymidine incorporation. The participants were categorized according to a change in proliferation over time. Significant decrease in endothelial cell proliferation correlated with the extent of weight loss in men, but not in women. This effect corresponded with changes in serum levels of leptin and adiponectin, but was not related to serum concentrations of several known angiogenic mediators (VEGF, MCP-1, TSP-1, MMP-9, angiopoietin-2).

CONCLUSION

Direction and magnitude of changes in serum-induced endothelial cell proliferation identifies patients with the greatest weight loss in response to modest calorie restriction.

Pinosylvin at a high concentration induces AMPK-mediated autophagy for preventing necrosis in bovine aortic endothelial cells

Pinosylvin is a known functional compound of the Pinus species. Pinosylvin at low concentrations (∼pmol/L) was reported to promote cell proliferation in endothelial cells. However, this study found that pinosylvin at a high concentration (100 μmol/L) induces cell death in bovine aortic endothelial cells. Therefore, we examined how pinosylvin was associated with apoptosis, autophagy, and necrosis. Pinosylvin at a high concentration appeared to promote caspase-3 activation, nuclear condensation, and the “flip-flop” of phosphatidylserine, indicating that pinosylvin induces apoptosis. However, based on flow cytometry data obtained from double-staining with annexin V and propidium iodide, pinosylvin was shown to inhibit necrosis, a postapoptotic process. Pinosylvin induced LC3 conversion from LC3-I to LC3-II and p62 degradation, which are important indicators of autophagy. In addition, AMP-activated protein kinase (AMPK) appeared to be activated by pinosylvin, and an AMPK inhibitor was markedly shown to reduce the LC3 conversion. The inhibitory effect of an AMPK inhibitor was reversed by pinosylvin. These results suggest that pinosylvin induces autophagy via AMPK activation. Further, necrosis was found to be promoted by an autophagy inhibitor and then restored by pinosylvin, while the caspase-3 inhibitor had no effect on necrosis. These findings indicate that pinosylvin-induced autophagy blocks necrotic progress in endothelial cells.