Cervical Vagus Nerve Stimulation Improves Neurologic Outcome After Cardiac Arrest in Mice by Attenuating Oxidative Stress and Excessive Autophagy.

Abstract

Background

Cerebral ischemia and reperfusion (I/R) induces oxidative stress and activates autophagy, leading to brain injury and neurologic deficits. Cervical vagus nerve stimulation (VNS) increases cerebral blood flow (CBF). In this study, we investigate the effect of VNS-induced CBF increase on neurologic outcomes after cardiac arrest (CA).

Materials and methods

A total of 40 male C57Bl/6 mice were subjected to ten minutes of asphyxia CA and randomized to vagus nerve isolation (VNI) or VNS treatment group. Eight mice received sham surgery and VNI. Immediately after resuscitation, 20 minutes of electrical stimulation (1 mA, 1 ms, and 10 Hz) was started in the VNS group. Electrocardiogram, blood pressure, and CBF were monitored. Neurologic and histologic outcomes were evaluated at 72 hours. Oxidative stress and autophagy were assessed at 3 hours and 24 hours after CA.

Results

Baseline characteristics were not different among groups. VNS mice had better behavioral performance (ie, open field, rotarod, and neurologic score) and less neuronal death (p < 0.05, vs VNI) in the hippocampus. CBF was significantly increased in VNS-treated mice at 20 minutes after return of spontaneous circulation (ROSC) (p < 0.05). Furthermore, levels of 8-hydroxy-2'-deoxyguanosine in the blood and autophagy-related proteins (ie, LC-3Ⅱ/Ⅰ, Beclin-1, and p62) in the brain were significantly decreased in VNS mice. Aconitase activity was also reduced, and the p-mTOR/mTOR ratio was increased in VNS mice.

Conclusions

Oxidative stress induced by global brain I/R following CA/ROSC leads to early excessive autophagy and impaired autophagic flux. VNS promoted CBF recovery, ameliorating these changes. Neurologic and histologic outcomes were also improved.

Department

Description

Provenance

Citation

Published Version (Please cite this version)

10.1016/j.neurom.2021.12.014

Publication Info

Duan, Weina, Qian Sun, Xiaojing Wu, Zhongyuan Xia, David S Warner, Luis Ulloa, Wei Yang, Huaxin Sheng, et al. (2022). Cervical Vagus Nerve Stimulation Improves Neurologic Outcome After Cardiac Arrest in Mice by Attenuating Oxidative Stress and Excessive Autophagy. Neuromodulation : journal of the International Neuromodulation Society, 25(3). pp. 414–423. 10.1016/j.neurom.2021.12.014 Retrieved from https://hdl.handle.net/10161/24852.

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Scholars@Duke

Yang

Wei Yang

Professor in Anesthesiology
Sheng

Huaxin Sheng

Associate Professor in Anesthesiology

We have successfully developed various rodent models of brain and spinal cord injuries in our lab, such as focal cerebral ischemia, global cerebral ischemia, head trauma, subarachnoid hemorrhage, intracerebral hemorrhage, spinal cord ischemia and compression injury. We also established cardiac arrest and hemorrhagic shock models for studying multiple organ dysfunction.  Our current studies focus on two projects. One is to examine the efficacy of catalytic antioxidant in treating cerebral ischemia and the other is to examine the efficacy of post-conditioning on outcome of subarachnoid hemorrhage induced cognitive dysfunction.


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