13-Methylberberine improves endothelial dysfunction by inhibiting NLRP3 inflammasome activation via autophagy induction in human umbilical vein endothelial cells

Zhihua Peng,Zhihao Liu,Zhenhua Huang,Lijin Zeng,Zhen Yang,Yan Xiong,Yijia Shao,Huanxing Su,Hong Zhan,Cong Zhang

doi:10.1186/s13020-020-0286-1

Abstract

BackgroundAtherosclerosis, the underlying cause of the majority of cardiovascular diseases, is a lipid-driven, inflammatory disease of the large arteries. Atherosclerotic cardiovascular disease (ASCVD) threatens human lives due to high morbidity and mortality. Many studies have demonstrated that atherosclerosis is accelerated via activation of the NLRP3 inflammasome. The NLRP3 inflammasome plays a critical role in the development of vascular inflammation and atherosclerosis. In atherosclerotic plaques, excessive generation of reactive oxygen species (ROS) activates the NLRP3 inflammasome. 13-Methylberberine (13-MB) is a newly synthesized compound used in traditional Chinese medicine that has outstanding antibacterial, antitumor, and antiobesity activities, especially anti-inflammatory activity. However, the role of 13-MB in atherosclerosis needs to be explored.MethodsCCK-8 assays and flow cytometry were conducted to determine the cell viability and apoptotic profiles of human umbilical vein endothelial cells (HUVECs) treated with 13-MB. Carboxy-DCFH-DA and JC-10 assays were used to measure ROS and determine mitochondrial membrane potential. Western blot analysis was performed to investigate proteins that are associated with the NLRP3 inflammasome and autophagy. ELISA was used to detect and quantify inflammatory cytokines related to the NLRP3 inflammasome. Transfection and confocal microscopy were conducted to observe autophagy.ResultsPretreatment with 13-MB markedly reduced cytotoxicity and apoptosis, as well as intracellular ROS production, in H2O2-induced HUVECs. Moreover, 13-MB showed a protective effect in maintaining mitochondrial membrane potential. 13-MB also suppressed NLRP3 inflammasome activation and promoted autophagy induction in HUVECs.Conclusion13-MB exerts cytoprotective effects in an H2O2-induced cell injury model by inhibiting NLRP3 inflammasome activation via autophagy induction in HUVECs. These anti-inflammatory and autophagy induction activities may provide valuable evidence for further investigating the potential role of 13-MB in atherosclerosis.

Highlights

Atherosclerosis, the underlying cause of the majority of cardiovascular diseases, is a lipid-driven, inflammatory disease of the large arteries
Flow cytometry analysis with Annexin V-FITC/PI double staining showed that apoptotic cells were significantly increased in the H2O2 treatment group compared with those of the control group, whereas the apoptotic rate decreased in response to 13-MB (Fig. 2). These results revealed that 13-MB prevented human umbilical vein endothelial cells (HUVECs) from undergoing H2O2-induced apoptosis
The level of IL-1β was significantly higher in the H 2O2-treated group than in the control group, while 13-MB treatment markedly reduced the level of IL-1β compared to that of H2O2-treated cells. These results showed that the NLRP3 inflammasome is directly activated when exposed to H2O2, which may influence the level IL-1β secretion in HUVECs

Summary

Introduction

Atherosclerosis, the underlying cause of the majority of cardiovascular diseases, is a lipid-driven, inflammatory disease of the large arteries. The NLRP3 inflammasome plays a critical role in the development of vascular inflammation and atherosclerosis. Excessive generation of reactive oxygen species (ROS) activates the NLRP3 inflammasome. Atherosclerosis is the most common cause of the underlying pathology of cardiovascular disease. It is characterized as a lipid-driven, chronic inflammatory disease of the large arteries, leading to high morbidity and mortality worldwide [1, 2]. Reactive oxygen species (ROS) play an essential role in NLRP3 inflammasome activation in atherosclerosis [7]. Accumulating evidence suggests that autophagy is stimulated by oxidized lipids, inflammation, and metabolic stress conditions in atherosclerotic plaques. Because atherosclerosis is an inflammatory disorder of the arterial intima, pharmacological antiinflammatory approaches may be developed to stabilize vulnerable, rupture-prone lesions through autophagy induction [11]

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