Objective

Many studies have already suggested the role of long non-coding RNAs (lncRNAs) in Alzheimer’s disease (AD), but the functions of lncRNA Taurine Upregulated Gene 1 (TUG1) in AD have been scarcely discussed. This study aims to verify how TUG1 affects hippocampal neurons in AD through modulation of microRNA-15a (miR-15a)/Rho-associated protein kinase 1 (ROCK1).

Method

AD mice was modeled through injection of β-amyloid 25-35 (Aβ25-35) into the lateral ventricle. After modeling, the mice were injected with altered TUG1 and/or miR-15a agomir lentiviruses. The spatial learning ability and memory ability of mice were detected through Morris water maze test. Hippocampal neuronal apoptosis and oxidative stress indicators in AD mice were then detected. The hippocampal neuron AD model was induced by Aβ25-35. Next, the neurons were, respectively, transfected with altered TUG1 vector and/or miR-15a mimics to determine the proliferation inhibition and apoptosis of hippocampal neurons. The interactions between TUG1 and miR-15a, and between miR-15a and ROCK1 were assessed using bioinformatic prediction, dual luciferase reporter gene assay and RNA-pull-down assay.

Results

In the animal models, Aβ25-35-induced mice exhibited decreased spatial learning and memory ability, obvious pathological injury, promoted hippocampal neuronal apoptosis and decreased antioxidant ability. TUG1 silencing and miR-15a elevation improved spatial learning ability and memory ability, ameliorated pathological injury, depressed neuronal apoptosis, and strengthened antioxidant ability of hippocampal neurons in AD mice. In cellular models, Aβ25-35-treated hippocampal neurons presented inhibited neuronal viability and promoted neuronal apoptosis. TUG1 silencing and miR-15a elevation increased viability and limited apoptosis of Aβ25-35-treated hippocampal neurons. TUG1 specifically bound to miR-15a, and miR-15a targeted ROCK1.

Conclusion

Collectively, this study reveals that TUG1 knockdown restricts apoptosis of hippocampal neurons in AD by elevating miR-15a and suppressing ROCK1 expression, and provides a new therapeutic target for AD treatment.

中文翻译：

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敲除长链非编码 RNA TUG1 通过提高 microRNA-15a 和抑制 ROCK1 表达来抑制阿尔茨海默病海马神经元的凋亡。

客观的

许多研究已经表明长链非编码 RNA (lncRNA) 在阿尔茨海默病 (AD) 中的作用，但 lncRNA 牛磺酸上调基因 1 (TUG1) 在 AD 中的作用却鲜有讨论。本研究旨在验证 TUG1 如何通过调节 microRNA-15a (miR-15a)/Rho 相关蛋白激酶 1 (ROCK1) 影响 AD 中的海马神经元。

方法

AD 小鼠通过将 β-淀粉样蛋白 25-35 (Aβ25-35) 注射到侧脑室进行建模。建模后，给小鼠注射改变的 TUG1 和/或 miR-15a agomir 慢病毒。通过Morris水迷宫试验检测小鼠的空间学习能力和记忆能力。然后检测AD小鼠的海马神经元凋亡和氧化应激指标。Aβ25-35诱导海马神经元AD模型。接下来，分别用改变的 TUG1 载体和/或 miR-15a 模拟物转染神经元，以确定海马神经元的增殖抑制和凋亡。使用生物信息学预测、双荧光素酶报告基因测定和 RNA-pull-down 测定评估 TUG1 和 miR-15a 之间以及 miR-15a 和 ROCK1 之间的相互作用。

结果

在动物模型中，Aβ25-35诱导的小鼠空间学习记忆能力下降，病理损伤明显，促进海马神经元凋亡，抗氧化能力下降。TUG1沉默和miR-15a升高提高了AD小鼠的空间学习能力和记忆能力，改善了病理损伤，抑制了神经元凋亡，增强了海马神经元的抗氧化能力。在细胞模型中，Aβ25-35 处理的海马神经元表现出抑制神经元活力并促进神经元凋亡。TUG1 沉默和 miR-15a 升高增加了 Aβ25-35 处理的海马神经元的活力并限制了细胞凋亡。TUG1 与 miR-15a 特异性结合，miR-15a 靶向 ROCK1。

结论

总的来说，本研究揭示了 TUG1 敲低通过提高 miR-15a 和抑制 ROCK1 表达来限制 AD 中海马神经元的凋亡，并为 AD 治疗提供新的治疗靶点。