中国神经再生研究(英文版) ›› 2018, Vol. 13 ›› Issue (7): 1216-1224.doi: 10.4103/1673-5374.235059

• 原著:脑损伤修复保护与再生 • 上一篇    下一篇

MicroRNA-219通过靶向CaMKⅡγ调节培养的海马神经元中谷氨酸诱导的神经毒性

  

  • 收稿日期:2017-12-08 出版日期:2018-07-15 发布日期:2018-07-15
  • 基金资助:

    国家自然科学基金(81101159)、江苏省自然科学基金(No.BK 20151268)

MicroRNA-219 alleviates glutamate-induced neurotoxicity in cultured hippocampal neurons by targeting calmodulin-dependent protein kinase II gamma

Ting Wang1, 2, Qun Cai3, Wen-Jie Yang4, Hai-Hua Fan4, Jian-Feng Yi4, Feng Xu1   

  1. 1 Department of Emergency, First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China;
    2 Department of Emergency, Affiliated Hospital of Nantong University, Nantong, Jiangsu Province, China;
    3 Department of Pediatrics, Affiliated Hospital of Nantong University, Nantong, Jiangsu Province, China;
    4 Medical College of Nantong University, Nantong, Jiangsu Province, China
  • Received:2017-12-08 Online:2018-07-15 Published:2018-07-15
  • Contact: Feng Xu, Ph.D., M.D.,suda_xf@163.com.
  • Supported by:

    This study was supported by the National Natural Science Foundation of China, No. 81101159; the Natural Science Foundation of Jiangsu Province of China, No. BK20151268

摘要:

脓毒症脑病是脓毒症常见并发症之一,但关于微小RNA(microRNA, miRNA)在脓毒症脑病中的研究还是很少。实验通过在大鼠海马神经元中转染miR-219模拟物(mimic)来过表达miR-219,观察miR-219对125 μM谷氨酸诱导的大鼠海马神经元毒性的保护作用,并阐述其作用机制。利用实时定量PCR(qRT-PCR)检测谷氨酸诱导海马神经元中miR-219和CaMKⅡγ mRNA的表达。海马神经元中转染miR-219模拟物(mimic)后,MTT和流式细胞仪分析法检测miR-219对谷氨酸诱导的海马神经元细胞活力和细胞凋亡的影响。利用荧光素酶报告基因系统检测CaMKⅡγ是miR-219作用靶基因。利用Western blot和挽救实验来检测CaMKⅡγ的表达,并进一步验证miR-219在海马神经元中是通过调控CaMKⅡγ来发挥作用。MTT和qRT-PCR结果显示,海马神经元细胞活力和miR-219表达在谷氨酸刺激的海马神经元中显著下降,但是CaMKⅡγ mRNA的表达却显著上升。MTT,流式细胞仪分析法和caspase-3活性分析结果显示,过表达miR-219能够提高谷氨酸诱导所引起的细胞活力,降低细胞凋亡率和caspase-3活性。荧光素酶报告基因系统检测结果显示,miR-219 mimic转染组中荧光素酶的活性显著降低。挽救实验结果说明,过表达CaMKⅡγ可以逆转miR-219的生物学效应。上述结果数据说明,谷氨酸诱导的大鼠海马神经元中miR-219表达下调,CaMKⅡγ是miR-219作用靶基因,miR-219能够通过负调控CaMKⅡγ来减轻谷氨酸诱导的神经元兴奋性毒性作用。

orcid:0000-0002-1496-9141(Feng Xu)

 

关键词: 神经再生, 脑损伤, 脓毒症脑病, miR-219, 海马神经元, 谷氨酸, 兴奋性毒性, 凋亡, Caspase-3, CaMKⅡ&gamma, 荧光报告酶基因系统, 神经保护

Abstract:

Septic encephalopathy is a frequent complication of sepsis, but there are few studies examining the role of microRNAs (miRs) in its pathogenesis.In this study, a miR-219 mimic was transfected into rat hippocampal neurons to model miR-219 overexpression. A protective effect of miR-219 was observed for glutamate-induced neurotoxicity of rat hippocampal neurons, and an underlying mechanism involving calmodulin-dependent protein kinase II γ (CaMKIIγ) was demonstrated. miR-219 and CaMKIIγ mRNA expression induced by glutamate in hippocampal neurons was determined by quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR). After neurons were transfected with miR-219 mimic, effects on cell viability and apoptosis were measured by 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry. In addition, a luciferase reporter gene system was used to confirm CaMKIIγ as a target gene of miR-219. Western blot assay and rescue experiments were also utilized to detect CaMKIIγ expression and further verify that miR-219 in hippocampal neurons exerted its effect through regulation of CaMKIIγ. MTT assay and qRT-PCR results revealed obvious decreases in cell viability and miR-219 expression after glutamate stimulation, while CaMKIIγ mRNA expression was increased. MTT,flow cytometry, and caspase-3 activity assays showed that miR-219 overexpression could elevate glutamate-induced cell viability, and reduce cell apoptosis and caspase-3 activity. Moreover, luciferase CaMKIIγ-reporter activity was remarkably decreased by co-transfection with miR-219 mimic, and the results of a rescue experiment showed that CaMKIIγ overexpression could reverse the biological effects of miR-219. Collectively, these findings verify that miR-219 expression was decreased in glutamate-induced neurons, CaMKIIγ was a target gene of miR-219, and miR-219 alleviated glutamate-induced neuronal excitotoxicity by negatively controlling CaMKIIγ expression.

Key words: nerve regeneration, brain injury, septic encephalopathy, miR-219, hippocampal neurons, glutamate, excitotoxicity, apoptosis;caspase-3, calmodulin-dependent protein kinase II γ, luciferase reporter gene system, neuroprotection, neural regeneration