Department of Biochemistry, Faculty of Pharmacy, Ege University, 35100 Bornova, Izmir, Turkey.
Department of Physiology, School of Medicine, Ege University, 35100 Bornova, Izmir, Turkey.
Molecules. 2019 Apr 8;24(7):1377. doi: 10.3390/molecules24071377.
Recently, nuclear translocation and stability of nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2) have gained increasing attention in the prevention of oxidative stress. The present study was aimed to evaluate the regulatory role of glycogen synthase kinase-3β (GSK-3β) inhibition by tideglusib through the Nrf2 pathway in a cellular damage model. Gene silencing (siRNA-mediated) was performed to examine the responses of Nrf2-target genes (i.e., heme oxygenase-1, NAD(P)H:quinone oxidoreductase1) to siRNA depletion of Nrf2 in MPP⁺-induced dopaminergic cell death. Nrf2 and its downstream regulated genes/proteins were analyzed using Real-time PCR and Western Blotting techniques, respectively. Moreover, free radical production, the changes in mitochondrial membrane potential, total glutathione, and glutathione-S-transferase were examined. The possible contribution of peroxisome proliferator-activated receptor gamma (PPARγ) to tideglusib-mediated neuroprotection was evaluated. The number of viable cells and mitochondrial membrane potential were increased following GSK-3β enzyme inhibition against MPP⁺. HO-1, NQO1 mRNA/protein expressions and Nrf2 nuclear translocation significantly triggered by tideglusib. Moreover, the neuroprotection by tideglusib was not observed in the presence of siRNA Nrf2. Our study supports the idea that GSK-3β enzyme inhibition may modulate the Nrf2/ARE pathway in cellular damage and the inhibitory role of tideglusib on GSK-3β along with PPARγ activation may be responsible for neuroprotection.
最近，核易位和核因子红细胞 2（NF-E2）相关因子 2（Nrf2）的稳定性在预防氧化应激方面受到越来越多的关注。本研究旨在通过 Nrf2 途径评估糖原合酶激酶-3β（GSK-3β）抑制 tideglusib 在细胞损伤模型中的调节作用。采用基因沉默（siRNA 介导）技术研究 Nrf2 靶基因（血红素加氧酶-1、NAD（P）H：醌氧化还原酶 1）对 MPP⁺诱导的多巴胺能细胞死亡中 Nrf2 基因沉默的反应。使用实时 PCR 和 Western Blotting 技术分别分析 Nrf2 及其下游调节基因/蛋白。此外，还检测了自由基产生、线粒体膜电位变化、总谷胱甘肽和谷胱甘肽-S-转移酶的变化。还评估了过氧化物酶体增殖物激活受体 γ（PPARγ）对 tideglusib 介导的神经保护作用的可能贡献。GSK-3β 酶抑制可增加 MPP⁺对细胞的存活数和线粒体膜电位。HO-1、NQO1 mRNA/蛋白表达和 Nrf2 核易位明显被 tideglusib 触发。此外，在 Nrf2 siRNA 存在的情况下，tideglusib 没有观察到神经保护作用。我们的研究支持这样一种观点，即 GSK-3β 酶抑制可能调节细胞损伤中的 Nrf2/ARE 途径，而 tideglusib 对 GSK-3β 的抑制作用以及对 PPARγ 的激活可能是神经保护的原因。
