Background:
Statin therapy is beneficial for ischemic stroke (IS) partly due to its pro-angiogenic effect. In diabetes patients, the accumulations of advanced glycation end products (AGEs) impair the angiogenic potential of endothelial cells (ECs), comprising collateral circulation in ischemic area. Autophagy affects endothelial function. The effect of statins on EC autophagy remains largely unknown. This study was to: 1.investigate the effect of Statin on the angiogenesis ability of ECs impaired by AGEs; 2. explore the autophagy of ECs in this process.
Methods:
primary cerebromicrovascular endothelial cells (CMVECs) were isolated from Wistar rats and cultured in medium. CMVECs were treated with AGEs. Subsequently, Simvastatin was added to cells. The angiogenic potential was evaluated by tube formation in vitro. Two autophagy marker, Beclin1 and LC3 protein expression were detected by western blot assay. The autophagosome quantitative analysis was evaluated by GFP-LC3-II assay.
Results:
AGEs (25mg/L, 50mg/L and 100mg/L) reduced the number of tube like structures in a dose dependant manner, accompanied by dramatically enhanced cellular autophagy level indicated by the increased GFP-LC3-II puncta number/cell and increased Beclin1 and LC3 expressions. Autophagy inhibitor 3-MA reversed the AGEs impaired angiogenic ability of CMVES. Simvastatin administration (10μmol/L) markedly increased the angiogenic potential of CMVES evaluated by tube formation ability, together with decreased Beclin1 and LC3, as well as decreased GFP-LC3-II puncta number/cell. AGEs significantly inhibits the PI3K/Akt/mTOR, while Simvastatin re-activate this pathway. More interestingly, the addition of mTOR inhibitor, rapamycin, which enhance the cellular autophagy, abolished the rescue effect of Simvastatin on the angiogenic potential of CMVECs impaired by AGEs.
Conclusion:
This study provides evidence that AGEs impair the angiogenesis ability via triggering high level of autophagy of CMVECs. Simvastatin rescue the angiogenic ability of CMVECs by surprising autophagy level via activation of PI3K/Akt/mTOR pathway.
Structural, Functional, and Metabolic Alterations in Human Cerebrovascular Endothelial Cells during Toxoplasma gondii Infection and Amelioration by Verapamil In Vitro
