The mechanism of CaMK2α-MCU-mitochondrial oxidative stress in bupivacaine-induced neurotoxicity

Zhongjie Liu; Wei Zhao; Pengfei Yuan; Pian Zhu; Keke Fan; Zhengyuan Xia; Shiyuan Xu

doi:10.1016/j.freeradbiomed.2020.04.002

The mechanism of CaMK2α-MCU-mitochondrial oxidative stress in bupivacaine-induced neurotoxicity

Free Radic Biol Med. 2020 May 20:152:363-374. doi: 10.1016/j.freeradbiomed.2020.04.002. Epub 2020 Apr 7.

Authors

Zhongjie Liu¹, Wei Zhao², Pengfei Yuan³, Pian Zhu⁴, Keke Fan⁵, Zhengyuan Xia⁶, Shiyuan Xu⁷

Affiliations

¹ Department of Anesthesiology, Zhujiang Hospital, Southern Medical University, Industrial Avenue Central 253, Guangzhou, 510282, Guangdong Province, China. Electronic address: 13580562690@163.com.
² Department of Anesthesiology, Zhujiang Hospital, Southern Medical University, Industrial Avenue Central 253, Guangzhou, 510282, Guangdong Province, China. Electronic address: zw618812@smu.edu.cn.
³ Department of Anesthesiology, Zhujiang Hospital, Southern Medical University, Industrial Avenue Central 253, Guangzhou, 510282, Guangdong Province, China. Electronic address: 395872516@qq.com.
⁴ Department of Anesthesiology, Zhujiang Hospital, Southern Medical University, Industrial Avenue Central 253, Guangzhou, 510282, Guangdong Province, China. Electronic address: 173927887@qq.com.
⁵ Department of Anesthesiology, Zhujiang Hospital, Southern Medical University, Industrial Avenue Central 253, Guangzhou, 510282, Guangdong Province, China. Electronic address: 1773562580@qq.com.
⁶ Department of Anesthesiology, University of Hong Kong, Hong Kong, China; Department of Anesthesiology and Pain Medicine, University of California Davis Health System, Sacramento, CA, 95817, USA. Electronic address: zyxia@hku.hk.
⁷ Department of Anesthesiology, Zhujiang Hospital, Southern Medical University, Industrial Avenue Central 253, Guangzhou, 510282, Guangdong Province, China. Electronic address: xsy998@smu.edu.cn.

PMID: 32275945
DOI: 10.1016/j.freeradbiomed.2020.04.002

Abstract

Ca²⁺/calmodulin dependent protein kinase2α (CaMK2α) is a serine/threonine protein kinase in neurons and leads to neuronal injury when it is activated abnormally. Bupivacaine, a local anesthetic commonly used in regional nerve block, could induce neurotoxicity via apoptotic injury. Whether or not CaMK2α is involved in bupivacaine-induced neurotoxicity and it is regulated remains unclear. In this study, bupivacaine was administered for intrathecal injection in C57BL/6 mice for building vivo injury model and was used to culture human neuroblastoma (SH-SY5Y) cells for building vitro injury model. The results showed that bupivacaine induced mitochondrial oxidative stress and neurons apoptotic injury, promoted phosphorylation of CaMK2α and cAMP-response element binding protein (CREB), and elevated mitochondrial Ca²⁺ uniporter (MCU) expression. Furthermore, it induced CaMK2α phosphorylation at Thr286 which phosphorylated CREB at Ser133 and up-regulated MCU transcriptional expression. Inhibition of CaMK2α-MCU signaling with knock-down of CaMK2α and MCU or with inhibitors (KN93 and Ru360) significantly mitigated bupivacaine-induced neurotoxic injury. Over-expression of CaMK2α significantly enhanced above oxidative injury. Activated MCU with agonist (spermine) reversed protective effect of siCaMK2α on bupivacaine-induced mitochondrial oxidative stress. Our data revealed that CaMK2α-MCU-mitochondrial oxidative stress pathway is a major mechanism whereby bupivacaine induces neurotoxicity and inhibition of above signaling could be a therapeutic strategy in the treatment of bupivacaine-induced neurotoxicity.

Keywords: Bupivacaine; CaMK2α; MCU; Mitochondrial oxidative stress; Neurotoxicity.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Bupivacaine* / toxicity
Calcium / metabolism
Cell Line, Tumor
Mice
Mice, Inbred C57BL
Neurotoxicity Syndromes*
Oxidative Stress

Substances

Calcium
Bupivacaine