中国神经再生研究(英文版)

中国神经再生研究(英文版) ›› 2023, Vol. 18 ›› Issue (10): 2219-2228.doi: 10.4103/1673-5374.369118

• 原著:脊髓损伤修复保护与再生 • 上一篇    下一篇

酪氨酸蛋白激酶受体A4可调节脊髓缺血再灌注损伤引起的运动神经元铁死亡

  

  • 出版日期:2023-10-15 发布日期:2023-03-28
  • 基金资助:
    国家自然科学基金项目（81771342）

Eph receptor A4 regulates motor neuron ferroptosis in spinal cord ischemia/reperfusion injury in rats

Yan Dong, Chunyu Ai, Ying Chen, Zaili Zhang, Dong Zhang, Sidan Liu, Xiangyi Tong, Hong Ma*   

  1. Department of Anesthesiology, the First Hospital of China Medical University, Shenyang, Liaoning Province, China
  • Online:2023-10-15 Published:2023-03-28
  • Contact: Hong Ma, MD, PhD, mahong5555@126.com.
  • Supported by:
    This work was supported by the National Natural Science Foundation of China, No. 81771342 (to HM).

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摘要：

酪氨酸蛋白激酶受体A4在神经系统中广泛表达。在运动神经元病中，酪氨酸蛋白激酶受体A4信号通路在调节运动神经元死亡中起着重要作用，而铁死亡是运动神经元死亡的一种重要方式。为了解EphA4信号是否参与脊髓缺血再灌注损伤中细胞铁死亡。实验通过夹闭左颈动脉和左锁骨下动脉14min建立脊髓缺血再灌注损伤大鼠模型，可见脊髓缺血再灌注损伤可导致脊髓前角神经元中酪氨酸蛋白激酶受体A4表达增加，与此同时，铁死亡相关指标明显恶化，且具有铁死亡特征的线粒体数量显著增加，并伴有运动神经功能和血脊髓屏障通透性恶化以及运动神经元死亡。而抑制酪氨酸蛋白激酶受体A4后，上述异常指标均明显恢复。然而，鞘内给予铁死亡诱导剂Erastin则可抵消抑制酪氨酸蛋白激酶受体A4的有益作用。进一步通过质谱和PubMed检索筛选与酪氨酸蛋白激酶受体A4相互作用的Beclin1和Erk1/2蛋白，发现抑制酪氨酸蛋白激酶受体A4表达可导致与Beclin1的结合减弱，磷酸化Beclin1减少，且Beclin1与XCT复合物合成降低。且抑制酪氨酸蛋白激酶受体A4还能降低酪氨酸蛋白激酶受体A4和磷酸化Erk1/2的结合，同时下调c-Myc、转铁蛋白受体1以及磷酸化Erk1/2水平。此外发现，酪氨酸蛋白激酶受体A4与磷酸化Beclin1和磷酸化ERK1/2在前角神经元中共定位。综上，酪氨酸蛋白激酶受体A4可通过促进Beclin1和XCT复合物的形成，激活Erk1/2/c-Myc/转铁蛋白受体1轴，参与调控脊髓缺血再灌注损伤中前角脊髓运动神经元的铁死亡。

https://orcid.org/0000-0003-4250-2247 (Hong Ma)

关键词: 酪氨酸蛋白激酶受体A4, 铁死亡, 脊髓缺血再灌注损伤, 运动神经元, Beclin1, Erk1/2, c-Myc, 转铁蛋白受体1, 磷酸化ERK1/2, 大鼠

Abstract: Previous studies have shown that the receptor tyrosine kinase Eph receptor A4 (EphA4) is abundantly expressed in the nervous system. The EphA4 signaling pathway plays an important role in regulating motor neuron ferroptosis in motor neuron disease. To investigate whether EphA4 signaling is involved in ferroptosis in spinal cord ischemia/reperfusion injury, in this study we established a rat model of spinal cord ischemia/reperfusion injury by clamping the left carotid artery and the left subclavian artery. We found that spinal cord ischemia/reperfusion injury increased EphA4 expression in the neurons of anterior horn, markedly worsened ferroptosis-related indicators, substantially increased the number of mitochondria exhibiting features consistent with ferroptosis, promoted deterioration of motor nerve function, increased the permeability of the blood-spinal cord barrier, and increased the rate of motor neuron death. Inhibition of EphA4 largely rescued these effects. However, intrathecal administration of the ferroptosis inducer Erastin counteracted the beneficial effects conferred by treatment with the EphA4 inhibitor. Mass spectrometry and a PubMed search were performed to identify proteins that interact with EphA4, with the most notable being Beclin1 and Erk1/2. Our results showed that inhibition of EphA4 expression reduced binding to Beclin1, markedly reduced p-Beclin1, and reduced Beclin1-XCT complex formation. Inhibition of EphA4 also reduced binding to p-Erk1/2 and markedly decreased the expression of c-Myc, transferrin receptor 1, and p-Erk1/2. Additionally, we observed co-localization of EphA4 and p-Beclin1 and of EphA4 and p-ERK1/2 in neurons in the anterior horn. In conclusion, EphA4 participates in regulating ferroptosis of spinal motor neurons in the anterior horn in spinal cord ischemia/reperfusion injury by promoting formation of the Beclin1-XCT complex and activating the Erk1/2/c-Myc/transferrin receptor 1 axis.

Key words: Beclin1, c-Myc, EphA4, Erk1/2, ferroptosis, motor neuron, p-Erk1/2, rat, spinal cord ischemia/reperfusion injury, transferrin receptor 1