Interleukin 6 induces apoptosis of human umbilical vein endothelial cells by inhibiting autophagy
10.16781/j.0258-879x.2018.03.0273
- Author:
Guan-Sheng LI
1
Author Information
1. Department of Emergency, The First Affiliated Hospital of Chongqing Medical University
- Publication Type:Journal Article
- Keywords:
Apoptosis;
Autophagy;
Interleukin-6;
Proliferation;
Sepsis;
Vascular endothelial cell
- From:
Academic Journal of Second Military Medical University
2018;39(3):273-279
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the effect of interleukin 6 (IL-6) on autophagy and apoptosis of human umbilical vein endothelial cells (HUVECs) and the interaction between autophagy and apoptosis. Methods HUVECs were cultured in vitro and stimulated with 5, 10, 20, 50 ng/L IL-6 for 24 h. The cell proliferation was detected by cell counting Kit- 8 (CCK-8) assay, the apoptosis was detected by flow cytometry, the acidic vesicle organelles were observed by monodansyl cadaverine staining, the ultra-microstructural cellular structure was observed by transmission electron microscope, and the expressions of apoptosis-related protein cleaved caspase-3 and autophagy-related proteins, including microtubule-associated protein 1 light chain 3 (LC3) and p62, were detected by Western blotting. HUVECs were stimulated with IL-6 combined with autophagy inhibitor 3-methyladenine (3-MA) or autophagy inducer sirolimus (SRL), and then the changes of cell proliferation, cell apoptosis and expressions of the above proteins were analyzed. Results Compared with the control group, the cell proliferation and the ratio of LC3 II/LC3 I in HUVECs in the IL-6 groups were significantly decreased (P<0.05), the apoptosis and the expressions of cleaved caspase-3 and p62 were significantly increased (P<0.05), the apoptotic vacuole number was significantly decreased (P<0.05), and the autophagy was reduced. The above effects were concentrationdependent (P<0.05). Compared with the IL-6 group, the autophagy of HUVECs in the IL-6 combined with 3-MA group was inhibited, the numbers of autophagosome and apoptotic vacuole were significantly decreased (P<0.05), LC3II/LC3 Iratio was significantly decreased (P<0.05), and the cell apoptosis and the expression of cleaved caspase-3 and p62 were significantly increased (P<0.05). Compared with the IL-6 group, the autophagy of HUVECs in the IL-6 combined with SRL group was promoted, the numbers of autophagosome and apoptotic vacuole were significantly increased (P<0.05), LC3 II/ LC3 Iratio was significantly increased (P<0.05), and the cell apoptosis and the expression of cleaved caspase-3 and p62 were significantly decreased (P<0.05). Conclusion IL-6 can induce the apoptosis of HUVECs by inhibiting autophagy.
