Introduction: Aromatic (Ar)-turmerone is a bioactive component of turmeric oil obtained from Curcuma longa. We recently identified a novel analog (A2) of ar-turmerone that protects dopaminergic neurons from toxic stimuli by activating nuclear factor erythroid 2-related factor 2 (Nrf2). D-cysteine increases Nrf2, leading to the activation of chaperone-mediated autophagy (CMA), a pathway in the autophagy-lysosome protein degradation system, in primary cultured cerebellar Purkinje cells. In this study, we attempted to identify novel analogs of ar-turmerone that activate Nrf2 more potently and investigated whether these analogs activate CMA.Methods: Four novel analogs (A4–A7) from A2 were synthesized. We investigated the effects of A2 and novel 4 analogs on Nrf2 expression via immunoblotting and CMA activity via fluorescence observation.Results: Although all analogs, including A2, increased Nrf2 expression, only A4 activated CMA in SH-SY5Y cells. Additionally, A4-mediated CMA activation was not reversed by Nrf2 inhibition, indicating that A4 activated CMA via mechanisms other than Nrf2 activation. We focused on p38, which participates in CMA activation. Inhibition of p38 significantly prevented A4-mediated activation of CMA. Although all novel analogs significantly increased the phosphorylation of p38 6 h after drug treatment, only A4 significantly increased phosphorylation 24 h after treatment. Finally, we revealed that A4 protected SH-SY5Y cells from the cytotoxicity of rotenone, and that this protection was reversed by inhibiting p38.Conclusion: These findings suggest that the novel ar-turmerone analog, A4, activates CMA and protects SH-SY5Y cells through the persistent activation of p38.

中文翻译：

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鉴定一种新型芳香姜黄酮类似物，通过 p38 的持续激活来激活分子伴侣介导的自噬


简介：芳香族 (Ar)-姜黄酮是从姜黄中提取的姜黄油的生物活性成分。我们最近发现了一种新的 ar-姜黄酮类似物 (A2)，它通过激活核因子红细胞 2 相关因子 2 (Nrf2) 来保护多巴胺能神经元免受毒性刺激。 D-半胱氨酸增加 Nrf2，导致原代培养的小脑浦肯野细胞中伴侣介导的自噬 (CMA) 的激活，CMA 是自噬-溶酶体蛋白质降解系统中的一种途径。在本研究中，我们试图鉴定能够更有效地激活 Nrf2 的新型 ar-姜黄酮类似物，并研究这些类似物是否激活 CMA。 方法：从 A2 合成了四种新型类似物 (A4–A7)。我们通过免疫印迹研究了A2和新的4个类似物对Nrf2表达的影响，并通过荧光观察研究了CMA活性。结果：尽管包括A2在内的所有类似物都增加了Nrf2表达，但只有A4在SH-SY5Y细胞中激活了CMA。此外，A4 介导的 CMA 激活不会被 Nrf2 抑制逆转，表明 A4 通过 Nrf2 激活以外的机制激活 CMA。我们关注参与 CMA 激活的 p38。 p38 的抑制显着阻止 A4 介导的 CMA 激活。尽管所有新型类似物在药物治疗后6小时显着增加p38的磷酸化，但只有A4在治疗后24小时显着增加磷酸化。最后，我们发现 A4 保护 SH-SY5Y 细胞免受鱼藤酮的细胞毒性，并且通过抑制 p38 可以逆转这种保护。结论：这些发现表明新型姜黄酮类似物 A4 激活 CMA 并保护 SH-SY5Y 细胞通过p38的持续激活。