中国神经再生研究(英文版) ›› 2024, Vol. 19 ›› Issue (12): 2698-2707.doi: 10.4103/NRR.NRR-D-23-01064

• 原著:脑损伤修复保护与再生 • 上一篇    下一篇

MicroRNA-502-3p 调节海马神经元的γ-氨基丁酸能突触功能

  

  • 出版日期:2024-12-15 发布日期:2024-03-30

MicroRNA-502-3p regulates GABAergic synapse function in hippocampal neurons

Bhupender Sharma1, Melissa M. Torres1, Sheryl Rodriguez1, Laxman Gangwani2, Subodh Kumar1, 3, *   

  1. 1Center of Emphasis in Neuroscience, Department of Molecular and Translational Medicine, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, TX, USA; 2Bond Life Sciences Center and Department of Veterinary Pathobiology, University of Missouri, Columbia, MO, USA; 3L. Frederick Francis Graduate School of Biomedical Sciences, Texas Tech University Health Sciences Center, El Paso, TX, USA
  • Online:2024-12-15 Published:2024-03-30
  • Contact: Subodh Kumar, PhD, subodh.kumar@ttuhsc.edu.
  • Supported by:
    This study was supported by the National Institute on Aging (NIA), National Institutes of Health (NIH), Nos. K99AG065645, R00AG065645, and R00AG065645-04S1 (to SK), and NIH research grants, NINDS, No. R01 NS115834 and NINDS/NIA, No. R01 NS115834-02S1 (to LG).

摘要:

有研究显示,γ-氨基丁酸(GABA)能抑制性神经元在包括阿尔茨海默病和阿尔茨海默病相关痴呆在内的许多神经系统疾病中减少。作者既往研究发现,在阿尔茨海默病突触中,microRNA-502-3p(miR-502-3p)上调,而γ-氨基丁酸A型受体亚基α-1(GABRα1)下调。为探讨 miR-502-3p 与 GABA 能突触功能之间新的分子关系,实验使用永生化小鼠海马神经元HT22和 miR-502-3p agomiRs 及 antagomiRs 进行了体外研究。计算机分析确定了 miR-502-3p 在 GABRα1 mRNA 上的多个结合位点。荧光素酶测定证实,miR-502-3p 靶向 GABRα1 基因并抑制荧光素酶活性。此外,qRT-PCR,miRNA 原位杂交、免疫印迹和免疫染色分析证实,过表达 miR-502-3p 会降低 GABRα1 的水平,而抑制 miR-502-3p 则会提高 GABRα1 蛋白表达水平。值得注意的是,由于 miR-502-3p 的过表达,细胞活力降低,坏死细胞数量增加。对人-γ-氨基丁酸受体 A- α1/β3/γ2(hGABAA-α1/β3/γ2)人胚肾HEK重组细胞系进行的全细胞膜片钳分析也显示,过表达 miR-502-3p 会降低 GABA 电流和 GABA 的整体功能,这表明 miR-502-3p 水平与 GABA 能突触功能呈负相关。此外,miR-502-3p 过表达时,阿尔茨海默病相关蛋白水平高;miR-502-3p 受抑制时,阿尔茨海默病相关蛋白水平低。此研究揭示了 miR-502-3p 调节 GABA 能突触的分子机制,并认为 miR-502-3p可能是调节包括阿尔茨海默病和阿尔茨海默病相关痴呆在内的神经系统疾病中GABA能突触功能的潜在治疗靶点。

https://orcid.org/0000-0003-4705-122X (Subodh Kumar)

Abstract: Gamma-aminobutyric acid (GABA)ergic neurons, the most abundant inhibitory neurons in the human brain, have been found to be reduced in many neurological disorders, including Alzheimer’s disease and Alzheimer’s disease-related dementia. Our previous study identified the upregulation of microRNA-502-3p (miR-502-3p) and downregulation of GABA type A receptor subunit α-1 in Alzheimer’s disease synapses. This study investigated a new molecular relationship between miR-502-3p and GABAergic synapse function. In vitro studies were performed using the mouse hippocampal neuronal cell line HT22 and miR-502-3p agomiRs and antagomiRs. In silico analysis identified multiple binding sites of miR-502-3p at GABA type A receptor subunit α-1 mRNA. Luciferase assay confirmed that miR-502-3p targets the GABA type A receptor subunit α-1 gene and suppresses the luciferase activity. Furthermore, quantitative reverse transcription-polymerase chain reaction, miRNA in situ hybridization, immunoblotting, and immunostaining analysis confirmed that overexpression of miR-502-3p reduced the GABA type A receptor subunit α-1 level, while suppression of miR-502-3p increased the level of GABA type A receptor subunit α-1 protein. Notably, as a result of the overexpression of miR-502-3p, cell viability was found to be reduced, and the population of necrotic cells was found to be increased. The whole cell patch-clamp analysis of human-GABA receptor A-α1/β3/γ2L human embryonic kidney (HEK) recombinant cell line also showed that overexpression of miR-502-3p reduced the GABA current and overall GABA function, suggesting a negative correlation between miR-502-3p levels and GABAergic synapse function. Additionally, the levels of proteins associated with Alzheimer’s disease were high with miR-502-3p overexpression and reduced with miR-502-3p suppression. The present study provides insight into the molecular mechanism of regulation of GABAergic synapses by miR-502-3p. We propose that micro-RNA, in particular miR-502-3p, could be a potential therapeutic target to modulate GABAergic synapse function in neurological disorders, including Alzheimer’s disease and Alzheimer’s disease-related dementia.

Key words: Alzheimer’s disease, GABAergic synapse, gamma-aminobutyric acid type A receptor subunit α-1 (GABRα1), microRNA-502-3p (miR-502-3p), miRNA in situ hybridization, Patch-clamp