Autophagy contributes to angiotensin II induced dysfunction of HUVECs

ABSTRACT

Background:

Signal transduction of Angiotensin II (Ang II) induced autophagy and its role in Ang II–induced dysfunction of HUVECs are still unclear.

Methods:

HUVECs are stimulated with different doses of Ang II (10-9-10-5 mol/L) for different time (6–48 hours). Autophagy-related protein markers: LC3, Beclin-1 and SQSTM1/p62 are measured by western blot.

Results:

Incubation with Ang II increases autophagic flux (Beclin-1, autophagosomes formation, and degradation of SQSTM1/p62, LC3-I). Increased autophagic levels are inhibited by pretreatment with Ang II type 1 receptor (AT1) blocker (Candesartan), NADPH Oxidase inhibitor (apocycin), mitochondrial K_ATP channels inhibitor (5-hydroxydecanoate, 5HD). 3-Methyladenine (inhibitors of autophagy) and rapamycin (activator of autophagy) respectively inhibits or activates Ang II–induced autophagy levels. Ang II decreases phosphorylation of endothelial nitric oxide synthase (eNOS) and NO production in HUVECs. L-NAME (NOS inhibitor) totally mimics the actions of Ang II on eNOS, NO production and autophagy levels. Rapamycin further decreases NO production combined with Ang II. Silence Atg5 completely reverses Ang II-activated autophagy levels.

Conclusions:

Our results demonstrate that Ang II stimulation increases autophagy levels via AT1 receptor, NADPH oxidase, mitochondrial K_ATP channel, eNOS, Atg5 signal pathway in HUVECs, and activation of autophagy contributes to Ang II induced dysfunction of HUVECs.

KEYWORDS:

• Angiotensin ii (ang ii)
• oxidative stress
• mitochondrial k_atp channel
• endothelial nitric oxide synthase (eNOS)
• autophagy

Author contributions

Investigation, Di Liu, Guan-Pin Sun, Yan Jiang, Rong Xue: project administration Lin-Hui Wang; writing—original draft preparation, Koji Murao; writing—review and editing, Guo-Xing Zhang; funding acquisition, Jing-Wei Chen. Guo-Xing Zhang. All authors have read and agreed to the published version of the manuscript.

Conflicts of interest

The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.

Institutional review board statement

The study was conducted according to the guidelines of the Declaration of Helsinki, and approved by the Ethics Committee) of Soochow University.

Data Availability Statement

The data presented in this study are available in this article.

Additional information

Funding

This research was funded by the National Natural Science Foundation of China (81470563, 81970422), Suzhou Municipal Science and Technology Bureau (SS201745, GSWS2019022, SYSD2020210), and 5th 333 Project of Jiangsu Province.