Natural-derived peptides are effective substances in attenuating oxidative stress. However, their specific mechanisms have not been fully elucidated, especially in peptide-mediated autophagy. In the present study, TWLPLPR, YVLLPSPK, and KVPPLLY, novel peptides from Juglans mandshurica Maxim, prevented ROS production, elevated GSH-Px activity and ATP levels, and ameliorated apoptosis in Aβ25-35 (at concentration of 50 μM for 24 h) induced PC12 cells (P < 0.01). Both western blot and immunofluorescence analysis illustrated that the peptides regulated Akt/mTOR signaling through p-Akt (Ser473) and p-mTOR (S2481) and promoted autophagy by increasing the levels of LC3-II/LC3-I and Beclin-1, while lowering p62 expression (P < 0.01). Autophagy inhibitor (3-methyladenine, 3-MA) and inducer (Rapamycin, RAPA) were combined used to confirm the contribution of peptide-regulated autophagy in anti-oxidative effects. Moreover, the peptides increased the level of LAMP1, LAMP2, and Cathepsin D (P < 0.05) and promoted the fusion with lysosomes to form autolysosomes, accelerating ROS removal. These data suggested that walnut-derived peptides regulated oxidative stress by promoting autophagy in the Aβ25-35-induced PC12 cells.

中文翻译：

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核桃衍生肽通过PC12细胞中抗氧化应激的Akt / mTOR信号通路通过自噬促进的神经保护作用。

天然来源的肽是减轻氧化应激的有效物质。但是，它们的具体机制尚未完全阐明，特别是在肽介导的自噬中。在本研究中，来自胡桃Maxim的新型肽TWLPLPR，YVLLPSPK和KVPPLLY阻止了ROS的产生，GSH-Px活性和ATP水平的升高，并改善了Aβ25-35的凋亡（浓度为50μM，持续24 h）。 PC12细胞（P <0.01）。免疫印迹和免疫荧光分析均表明，该肽通过p-Akt（Ser473）和p-mTOR（S2481）调节Akt / mTOR信号传导，并通过增加LC3-II / LC3-I和Beclin-1的水平促进自噬。降低p62表达（P <0.01）。自噬抑制剂（3-甲基腺嘌呤，3-MA）和诱导剂（雷帕霉素，RAPA）组合用于确认肽调节的自噬在抗氧化作用中的作用。此外，这些肽增加了LAMP1，LAMP2和组织蛋白酶D的水平（P <0.05），并促进了与溶酶体的融合形成自溶酶体，从而加速了ROS的去除。这些数据表明，核桃来源的肽通过促进Aβ25-35诱导的PC12细胞中的自噬来调节氧化应激。