Clinical Pharmacology Laboratory, Department of Pharmacy, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, People's Republic of China.
Department of Human Anatomy, Institute of Neuroscience, Chongqing Medical University, Chongqing, 400016, People's Republic of China.
Neurochem Res. 2018 Feb;43(2):297-305. doi: 10.1007/s11064-017-2421-7. Epub 2017 Oct 31.
Oxidative stress and cytotoxic damage induced by amyloid beta (Aβ) have been considered pivotal in the pathogenesis of Alzheimer's disease (AD) and may represent a target for treatment. The phosphatidylinositol 3-kinase (PI3K)/Akt pathway elicits a survival signal to protect against multiple injuries, and the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2), a downstream target of the PI3K/Akt pathway, can bind to HO-1. Resveratrol, a natural polyphenol derived from grapes, has been widely reported to have diverse antioxidative effects against AD, but the mechanisms have not been fully elucidated. The present study aims to investigate the effects of resveratrol on Aβ-induced cytotoxicity in PC12 cells and to explore the potential mechanisms of these effects. PC12 cells were cultured and treated with Aβ. Oxidative stress was assessed by measuring malondialdehyde (MDA), glutathione (GSH), and superoxide dismutase (SOD) levels. After treating with resveratrol at different concentrations (0, 10, 20, 40 μM) and for different durations (24, 48, 72 h), the generation of MDA, GSH, and SOD were detected; cell viability was assessed by MTT assay. The production of reactive oxygen species (ROS) was determined using an ROS Assay Kit. Western blotting was used to detect the protein expression. Our studies showed that pretreatment with resveratrol could reduce Aβ-induced oxidative stress in PC12 cells by inhibiting the generation of MDA and ROS and increasing the production of SOD and GSH. Resveratrol markedly attenuated the Aβ-induced loss in cell viability in PC12 cells in both a dose- and time-dependent manner. More importantly, resveratrol stimulated the activation of HO-1, Nrf2, PI3K, and phosphorylated Akt. Notably, the neuroprotective effects of resveratrol were eliminated by the HO-1 inhibitor zinc protoporphyrin IX (ZnPP), Nrf2 small interfering RNA (siRNA), and the PI3K/Akt inhibitor LY294002. Taken together, the findings suggest that the cytoprotection of resveratrol against the cytotoxicity induced by Aβ in PC12 cells is through the upregulation of HO-1 expression via the activation of the PI3K/AKT/Nrf2 intracellular signaling pathway, which might provide novel insights for understanding the mechanism of the neuroprotective effect of resveratrol as an anti-AD drug.
氧化应激和细胞毒性损伤由淀粉样蛋白 β（Aβ）诱导被认为是阿尔茨海默病（AD）发病机制中的关键因素，可能是治疗的靶点。磷脂酰肌醇 3-激酶（PI3K）/Akt 途径引发存活信号以防止多种损伤，转录因子核因子红细胞 2 相关因子 2（Nrf2）是 PI3K/Akt 途径的下游靶标，可与 HO-1 结合。白藜芦醇是一种源自葡萄的天然多酚，已广泛报道具有多种抗氧化作用，可以抵抗 AD，但机制尚未完全阐明。本研究旨在探讨白藜芦醇对 PC12 细胞中 Aβ诱导的细胞毒性的影响，并探讨这些作用的潜在机制。将 PC12 细胞培养并用 Aβ处理。通过测量丙二醛（MDA）、谷胱甘肽（GSH）和超氧化物歧化酶（SOD）水平来评估氧化应激。用不同浓度（0、10、20、40μM）和不同时间（24、48、72h）的白藜芦醇处理后，检测 MDA、GSH 和 SOD 的产生；通过 MTT 测定法评估细胞活力。使用 ROS 测定试剂盒测定活性氧（ROS）的产生。Western blot 用于检测蛋白表达。我们的研究表明，白藜芦醇预处理可通过抑制 MDA 和 ROS 的产生以及增加 SOD 和 GSH 的产生来减轻 Aβ诱导的 PC12 细胞氧化应激。白藜芦醇以剂量和时间依赖的方式显着减轻 Aβ诱导的 PC12 细胞活力丧失。更重要的是，白藜芦醇刺激 HO-1、Nrf2、PI3K 和磷酸化 Akt 的激活。值得注意的是，HO-1 抑制剂锌原卟啉 IX（ZnPP）、Nrf2 小干扰 RNA（siRNA）和 PI3K/Akt 抑制剂 LY294002 消除了白藜芦醇的神经保护作用。综上所述，这些发现表明，白藜芦醇对 PC12 细胞中 Aβ诱导的细胞毒性的细胞保护作用是通过激活 HO-1 表达来实现的，这是通过激活 PI3K/AKT/Nrf2 细胞内信号通路实现的，这可能为理解白藜芦醇作为抗 AD 药物的神经保护作用机制提供新的见解。
