Ni Chunjue, Huang Baojun, Huang Yufan, Wen Zhengde, Luo Shan
Department of Anesthesiology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China.
Wenzhou Medical University, Wenzhou, Zhejiang, China.
Brain Res Bull. 2024 Oct 15;217:111071. doi: 10.1016/j.brainresbull.2024.111071. Epub 2024 Sep 5.
Cerebral ischemia-reperfusion (CIR) injury is a devastating consequence of stroke characterized by oxidative stress-induced neuronal damage. Electroacupuncture (EA) has emerged as a potential therapeutic intervention for ischemic stroke, but its underlying mechanisms remain incompletely understood. This study aimed to elucidate whether EA exerts anti-oxidative stress effects against CIR injury by modulating the GSK-3β/Nrf2 pathway.
CIR mouse models were established using the suture-occluded method and underwent EA pretreatment. Cognitive and neurologic function, cerebral infarct volume, and neuronal damage were assessed in mice. Oxidative stress levels and the expression of components of the GSK-3β/Nrf2 pathway in the cerebral cortex were measured. The regulatory effect of GSK-3β on Nrf2 and its role in electroacupuncture to alleviate oxygen-glucose deprivation/reoxygenation (OGD/R)-induced neuronal injury were investigated by modulating GSK-3β expression in HT22 hippocampal neuronal cells and electroacupuncture serum intervention. Ultimately, Nrf2 knockout mice, GSK-3β knockout mice, and wild-type mice treated with TBHQ (an Nrf2 activator) were utilized for further validation.
EA pretreatment improved cognitive impairment and neuronal damage induced by CIR injury. Mechanistically, EA inhibited oxidative stress in the cerebral cortex, manifested by reduced levels of reactive oxygen species and malondialdehyde, along with increased superoxide dismutase activity. Furthermore, EA upregulated the expression of Nrf2 and its downstream antioxidant enzymes HO-1 and NQO1, while Keap1 expression remained unaffected. In vitro, GSK-3β overexpression inhibited the protective effects of EA serum on OGD/R-induced neuronal damage. In vivo, knockout of either Nrf2 or Gsk-3β genes abolished the neuroprotective effects of EA, and TBHQ exerted effects similar to EA, confirming the significant role of GSK-3β/Nrf2 in mediating EA antioxidative effects.
EA exerts antioxidative stress effects against CIR injury by activating the GSK-3β/Nrf2 signaling pathway, independent of Keap1 regulation.
脑缺血再灌注（CIR）损伤是中风的一种毁灭性后果，其特征为氧化应激诱导的神经元损伤。电针（EA）已成为缺血性中风的一种潜在治疗干预手段，但其潜在机制仍未完全明确。本研究旨在阐明电针是否通过调节GSK-3β/Nrf2通路对CIR损伤发挥抗氧化应激作用。
采用线栓法建立CIR小鼠模型并进行电针预处理。评估小鼠的认知和神经功能、脑梗死体积及神经元损伤情况。检测大脑皮质中的氧化应激水平以及GSK-3β/Nrf2通路各组分的表达。通过调节HT22海马神经元细胞中的GSK-3β表达及电针血清干预，研究GSK-3β对Nrf2的调控作用及其在电针减轻氧糖剥夺/复氧（OGD/R）诱导的神经元损伤中的作用。最后，利用Nrf2基因敲除小鼠、GSK-3β基因敲除小鼠以及用叔丁基对苯二酚（一种Nrf2激活剂）处理的野生型小鼠进行进一步验证。
电针预处理改善了CIR损伤诱导的认知障碍和神经元损伤。机制上，电针抑制了大脑皮质中的氧化应激，表现为活性氧和丙二醛水平降低，同时超氧化物歧化酶活性增加。此外，电针上调了Nrf2及其下游抗氧化酶HO-1和NQO1的表达，而Keap1表达未受影响。在体外，GSK-3β过表达抑制了电针血清对OGD/R诱导的神经元损伤的保护作用。在体内，敲除Nrf2或Gsk-3β基因均消除了电针的神经保护作用，且叔丁基对苯二酚发挥了与电针相似的作用，证实了GSK-3β/Nrf2在介导电针抗氧化作用中的重要作用。
电针通过激活GSK-3β/Nrf2信号通路对CIR损伤发挥抗氧化应激作用，且不依赖于Keap1调控。
