Abstract

Background

Humanin (HN) is an extensive neuroprotective peptide. This study aims to investigate the neuroprotective effects of HN on Calyculin A (CA)-induced neurotoxicities in cortical neurons and the underlying mechanism.

Methods

CA was added into the cultured cortical neurons to induce neurotoxicity. Cortical neurons were preincubated with HN which plays a protective role. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), lactate dehydrogenase (LDH), and Calcein-AM were applied to evaluate the neural insults. Caspase 3 signal and Tunnel were performed to test neural apoptosis. Western blot analysis was used to detect the expressions of phosphorylated tau. The corresponding kits were used to measure the contents of malondialdehyde (MDA) and superoxide dismutase (SOD), and the activity of PP2A, respectively.

Results

HN preincubation preserved cell viability, protected the neurons, alleviated oxidative stress, and reserved PP2A activity. It also blocked tau overphosphorylation at Ser199/202, Ser396, and Thr231 sites and protected neurons against CA-induced insults.

Conclusion

These results suggest that HN may serve as a potential therapeutic agent to prevent the pathological changes induced by CA via modulating the activity of PP2A and oxidative stress in neurodegenerative diseases.

中文翻译：

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Humanin 通过增加 PP2A 活性和 SOD 保护皮质神经元免受花萼蛋白 A 诱导的神经毒性

摘要

背景

Humanin (HN) 是一种广泛的神经保护肽。本研究旨在探讨 HN 对 Calyculin A (CA) 诱导的皮质神经元神经毒性的神经保护作用及其潜在机制。

方法

将CA添加到培养的皮质神经元中以诱导神经毒性。皮质神经元与起保护作用的 HN 预孵育。应用 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)、乳酸脱氢酶 (LDH) 和 Calcein-AM 来评估神经损伤。进行 Caspase 3 信号和隧道以测试神经细胞凋亡。Western印迹分析用于检测磷酸化tau的表达。分别用相应的试剂盒测定丙二醛（MDA）和超氧化物歧化酶（SOD）的含量，以及PP2A的活性。

结果

HN 预孵育保留了细胞活力，保护了神经元，减轻了氧化应激，并保留了 PP2A 活性。它还阻断了 tau 在 Ser199/202、Ser396 和 Thr231 位点的过度磷酸化，并保护神经元免受 CA 诱导的损伤。

结论

这些结果表明，HN 可作为一种潜在的治疗剂，通过调节 PP2A 的活性和神经退行性疾病中的氧化应激来预防 CA 引起的病理变化。