Department of Neurology, The First Clinical College of Harbin Medical University, Harbin, China.
Department of Neurology, The Second Clinical College of Harbin Medical University, Harbin, China.
Cell Prolif. 2021 Apr;54(4):e13003. doi: 10.1111/cpr.13003. Epub 2021 Feb 21.
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the progressive loss of motor neurons (MN). CREB pathway-mediated inhibition of apoptosis contributes to neuron protection, and PAK4 activates CREB signalling in diverse cell types. This study aimed to investigate PAK4's effect and mechanism of action in ALS.
We analysed RNA levels by qRT-PCR, protein levels by immunofluorescence and Western blotting, and apoptosis by flow cytometry and TUNEL staining. Cell transfection was performed for in vitro experiment. Mice were injected intraspinally to evaluate PAK4 function in vivo experiment. Rotarod test was performed to measure motor function.
The expression and activation of PAK4 significantly decreased in the cell and mouse models of ALS as the disease progressed, which was caused by the negative regulation of miR-9-5p. Silencing of PAK4 increased the apoptosis of MN by inhibiting CREB-mediated neuroprotection, whereas overexpression of PAK4 protected MN from hSOD1 -induced degeneration by activating CREB signalling. The neuroprotective effect of PAK4 was markedly inhibited by CREB inhibitor. In ALS models, the PAK4/CREB pathway was inhibited, and cell apoptosis increased. In vivo experiments revealed that PAK4 overexpression in the spinal neurons of hSOD1 mice suppressed MN degeneration, prolonged survival and promoted the CREB pathway.
PAK4 protects MN from degeneration by activating the anti-apoptotic effects of CREB signalling, suggesting it may be a therapeutic target in ALS.
肌萎缩侧索硬化症（ALS）是一种致命的神经退行性疾病，其特征是运动神经元（MN）的进行性丧失。CREB 通路介导的细胞凋亡抑制有助于神经元保护，而 PAK4 在多种细胞类型中激活 CREB 信号。本研究旨在探讨 PAK4 在 ALS 中的作用和作用机制。
我们通过 qRT-PCR 分析 RNA 水平，通过免疫荧光和 Western blot 分析蛋白水平，通过流式细胞术和 TUNEL 染色分析细胞凋亡。进行细胞转染以进行体外实验。通过脊髓内注射评估体内实验中 PAK4 的功能。进行旋转棒测试以测量运动功能。
随着疾病的进展，ALS 细胞和小鼠模型中 PAK4 的表达和激活显著降低，这是由 miR-9-5p 的负调控引起的。沉默 PAK4 通过抑制 CREB 介导的神经保护作用增加 MN 的凋亡，而过表达 PAK4 通过激活 CREB 信号来保护 MN 免受 hSOD1 诱导的变性。CREB 抑制剂显著抑制 PAK4 的神经保护作用。在 ALS 模型中，PAK4/CREB 通路受到抑制，细胞凋亡增加。体内实验表明，hSOD1 小鼠脊髓神经元中 PAK4 的过表达抑制 MN 变性，延长存活时间并促进 CREB 通路。
PAK4 通过激活 CREB 信号的抗细胞凋亡作用来保护 MN 免受变性，这表明它可能是 ALS 的治疗靶点。
Zotero 插件
