Institute of Geriatrics, Affiliated People's Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China.
Department of Neurology, Affiliated People's Hospital of Nanchang University, Jiangxi 330006, P.R. China.
Mol Med Rep. 2021 Sep;24(3). doi: 10.3892/mmr.2021.12296. Epub 2021 Jul 19.
Alzheimer's disease (AD), one of the most common types of chronic neurodegenerative diseases, is pathologically characterized by the formation of amyloid β (Aβ) peptide‑containing plaques and neurofibrillary tangles. Among Aβ peptides, Aβ induces neuronal toxicity and neurodegeneration. In our previous studies, Cdk5 was found to regulate Aβ‑induced mitochondrial fission via the phosphorylation of dynamin‑related protein 1 (Drp1) at Ser579. However, whether blockage of Drp1 phosphorylation at Ser579 protects neurons against Aβ‑induced degeneration remains to be elucidated. Thus, the aim the present study was to examine the effect of mutant Drp1‑S579A on neurodegeneration and its underlying mechanism. First, the phosphorylation‑defect (phospho‑defect) mutant, Lenti‑Drp1‑S579A was constructed. Phospho‑defect Drp1‑S579A expression was detected in primary cultures of mouse cortical neurons infected with Lenti‑Drp1‑S579A using western blotting and it was found to successfully attenuate the phosphorylation of endogenous Drp1 at Ser579. In primary neuronal cultures, the neuronal processes were evaluated under microscopy. Treatment with 10 M Aβ1‑42 significantly decreased dendritic density and length, spine outgrowth and synapse number. As expected, infection of neurons with Lenti‑Drp1‑S579A efficiently alleviated the inhibitory effect of Aβ on neurite outgrowth and synapse density. In addition, infection with Lenti‑Drp1‑S579A abolished the cleavage of caspase‑3 and apoptosis in neurons exposed to Aβ. Thus, the current data demonstrated that blockage of Drp1 phosphorylation at Ser579 may be an effective strategy to protect neurons against Aβ‑induced degeneration and apoptosis. These findings underline the therapeutic potential of targeting Drp1 in the treatment of AD.
阿尔茨海默病（AD）是最常见的慢性神经退行性疾病之一，其病理特征为淀粉样β（Aβ）肽含斑块和神经原纤维缠结的形成。在 Aβ 肽中，Aβ 诱导神经元毒性和神经退行性变。在我们之前的研究中，发现细胞周期蛋白依赖性激酶 5（Cdk5）通过磷酸化动力相关蛋白 1（Drp1）Ser579 调节 Aβ诱导的线粒体裂变。然而，阻断 Drp1 Ser579 磷酸化是否能保护神经元免受 Aβ诱导的变性仍需阐明。因此，本研究旨在探讨突变型 Drp1-S579A 对神经退行性变的影响及其潜在机制。首先，构建了磷酸化缺陷（磷酸化缺陷）突变体 Lenti-Drp1-S579A。用 Western blot 检测感染 Lenti-Drp1-S579A 的小鼠皮质神经元原代培养物中磷酸化缺陷 Drp1-S579A 的表达，发现其成功减弱了内源性 Drp1 Ser579 的磷酸化。在原代神经元培养物中，在显微镜下评估神经元突起。用 10μM Aβ1-42 处理显著降低了树突密度和长度、刺突生长和突触数量。正如预期的那样，用 Lenti-Drp1-S579A 感染神经元有效地减轻了 Aβ 对轴突生长和突触密度的抑制作用。此外，用 Lenti-Drp1-S579A 感染神经元消除了 Aβ 暴露的神经元中 caspase-3 的切割和凋亡。因此，目前的数据表明，阻断 Drp1 Ser579 的磷酸化可能是保护神经元免受 Aβ诱导的变性和凋亡的有效策略。这些发现强调了靶向 Drp1 在治疗 AD 中的治疗潜力。
