The translational proteome modulated by 20(S)-protopanaxadiol in endothelial cells

Background: 20(S)-protopanaxadiol (PPD), a natural compound of dammarane ginsenoside purified from the ginseng plant, exhibits strong anticancer properties. It has also been reported to have strong antioxidant activity and plays a role in cardiovascular protection. However, the downstream signaling mechanism PPD employs is still unclear and requires further elucidation.

Methods: Endothelial cells (ECs) EAhy 926 were used to investigate the growth promoting effect of PPD. The protein lysates extracted from both mock-and PPD-treated cells were separated by two-dimensional gel electrophoresis (2-DE) to monitor protein changes. After image analysis, proteins with significant change in the expression level were further identified by mass spectrometry. Western blot was applied to further confirm the protein variations in the 2-DE assay.

Results: In the current study, we found that treatment with PPD (10 μg/ml) significantly increased ECs healing. The translational proteome was established according to 16 up-regulated and 8 down-regulated proteins identified in 2-DE. These proteins were reported to function as energy homeostasis and in the prevention of oxidative stress. The elevated expressions of heme oxygenase 1 (HO-1) and glutathione synthetase (GSS) were further confirmed in the western blot analysis.

Conclusions: According to the information obtained from translational proteome, we delineated that PPD mediated vascular homeostasis through the up-regulation of anti-oxidative proteins. Additional functional investigations are necessary regarding the HO-1 and GSS proteins.