中国神经再生研究(英文版)

中国神经再生研究(英文版) ›› 2022, Vol. 17 ›› Issue (3): 661-672.doi: 10.4103/1673-5374.320991

• 原著:脑损伤修复保护与再生 • 上一篇    下一篇

Krüppel样因子7可减轻创伤性脑损伤后的海马神经元损伤

  

  • 出版日期:2022-03-15 发布日期:2021-10-15

Krüppel-like factor 7 attenuates hippocampal neuronal injury after traumatic brain injury

Wen-Yuan Li1, #, Xiu-Mei Fu2, 3, #, Zhen-Dong Wang4, Zhi-Gang Li5, Duo Ma1, Ping Sun1, Gui-Bo Liu1, Xiao-Feng Zhu1, *, Ying Wang1, *   

  1. 1Institute of Neural Tissue Engineering, Mudanjiang Medical University, Mudanjiang, Heilongjiang Province, China; 2Department of Anatomy, College of Basic Medical Sciences, Chengde Medical University, Chengde, Hebei Province, China; 3Hebei Key Laboratory of Nerve Injury and Repair, Chengde Medical University, Chengde, Hebei Province, China; 4Department of Otorhinolaryngology, Mudanjiang City Second People’s Hospital, Mudanjiang, Heilongjiang Province, China; 5The First Department of General Surgery, Hongqi Hospital, Mudanjiang Medical University, Mudanjiang, Heilongjiang Province, China
  • Online:2022-03-15 Published:2021-10-15
  • Contact: Ying Wang, PhD, yingwang2016@sina.com; Xiao-Feng Zhu, PhD, sjkx@sohu.com.
  • Supported by:
    This study was supported by the National Natural Science Foundation of China, No. 81870977 (to YW); the Natural Science Foundation of Heilongjiang of China, No. H2018068 (to WYL); the Basic Research Operating Expenses Program of Heilongjiang Provincial Universities of China, No. 2019-KYYWFMY-0018 (to WYL); the Graduate Innovative Research Projects of Mudanjiang Medical College of China, No. YJSCX-MY22 (to DM); Key projects of Education Department of Hebei Province of China, No. ZD2020178 (to XMF); and Hebei Key Laboratory of Nerve Injury and Repair of China (to XMF).

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摘要：

作者前期研究发现转录因子Krüppel样因子7可显著促进周围神经的再生及脊髓损伤后运动功能恢复，同时还发现Krüppel样因子7也可参与创伤性脑损伤神经损伤，但其调控机制尚不明确。（1）此次实验首先应用牵张损伤结合氧糖剥夺建立了模拟创伤性脑损伤的HT22细胞模型，然后以腺相关病毒转染Krüppel样因子，见Krüppel样因子7显著减少了牵张损伤结合氧糖剥夺诱导的细胞凋亡，激活Caspase-3和乳酸脱氢酶，并下调促凋亡蛋白Bax和cleaved caspase-3的表达，同时增加βⅢ-微管蛋白和抗凋亡蛋白Bcl-2的表达。Krüppel样因子7在过表达的同时加剧牵张损伤结合氧糖剥夺诱导的HT22细胞中JAK2和STAT3的磷酸化。同时免疫共沉淀结果也显示出Krüppel样因子7可直接与磷酸化STAT3产生相互作用。而JAK2/STAT3选择性抑制剂AG490预处理即可减轻Krüppel样因子7的保护作用；（2）进一步利用控制性皮质撞击方法建立了小鼠创伤性脑损伤模型，并在造模前30min时转染携带Krüppel样因子7的慢病毒，发现损伤后1d时海马组织中Krüppel样因子7蛋白和mRNA表达增加，而3d后基本恢复正常。Krüppel样因子7可减轻损伤侧海马的萎缩，减少皮质病变体积，并降低促凋亡蛋白Bax和cleaved caspase-3的表达，同时还能增加BrdU阳性神经元数量以及Bcl-2蛋白的表达。另外转染Krüppel样因子7也显著改善了创伤性脑损伤小鼠的神经功能。与体外实验结果一致。Krüppel样因子7还表现出显著上调损伤侧海马组织中JAK2和STAT3磷酸化的作用；（3）以上结果表明Krüppel样因子7可保护创伤性脑损伤海马神经元，通过激活JAK2/STAT3信号通路而实现这一作用。实验于2018年3月6日经牡丹江医学院动物伦理会的批准（批准号mdjyxy-2018-0012）。

https://orcid.org/0000-0003-4075-781X (Ying Wang); https://orcid.org/0000-0002-1694-5178 (Wen-Yuan Li)

关键词: Kruppel样因子7, JAK2/STAT3信号通路, 创伤性脑损伤, 神经保护, 牵张损伤, 氧糖剥夺, 细胞凋亡, 海马

Abstract: Our previous study has shown that the transcription factor Krüppel-like factor 7 (KLF7) promotes peripheral nerve regeneration and motor function recovery after spinal cord injury. KLF7 also participates in traumatic brain injury, but its regulatory mechanisms remain poorly understood. In the present study, an HT22 cell model of traumatic brain injury was established by stretch injury and oxygen-glucose deprivation. These cells were then transfected with an adeno-associated virus carrying KLF7 (AAV-KLF7). The results revealed that, after stretch injury and oxygen-glucose deprivation, KLF7 greatly reduced apoptosis, activated caspase-3 and lactate dehydrogenase, downregulated the expression of the apoptotic markers B-cell lymphoma 2 (Bcl-2)-associated X protein (Bax) and cleaved caspase-3, and increased the expression of βIII-tubulin and the antiapoptotic marker Bcl-2. Furthermore, KLF7 overexpression upregulated Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3) phosphorylation in HT22 cells treated by stretch injury and oxygen-glucose deprivation. Immunoprecipitation assays revealed that KLF7 directly participated in the phosphorylation of STAT3. In addition, treatment with AG490, a selective inhibitor of JAK2/STAT3, weakened the protective effects of KLF7. A mouse controlled cortical impact model of traumatic brain injury was then established. At 30 minutes before modeling, AAV-KLF7 was injected into the ipsilateral lateral ventricle. The protein and mRNA levels of KLF7 in the hippocampus were increased at 1 day after injury and recovered to normal levels at 3 days after injury. KLF7 reduced ipsilateral hippocampal atrophy, decreased the injured cortex volume, downregulated Bax and cleaved caspase-3 expression, and increased the number of 5-bromo-2′-deoxyuridine-positive neurons and Bcl-2 protein expression. Moreover, KLF7 transfection greatly enhanced the phosphorylation of JAK2 and STAT3 in the ipsilateral hippocampus. These results suggest that KLF7 may protect hippocampal neurons after traumatic brain injury through activation of the JAK2/STAT3 signaling pathway. The study was approved by the Institutional Review Board of Mudanjiang Medical University, China (approval No. mdjyxy-2018-0012) on March 6, 2018.

Key words: apoptosis, hippocampus, JAK2/STAT3, Kruppel-like factor 7, neuroprotection, oxygen-glucose deprivation, stretch, traumatic brain injury

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