Dept. of Anatomy and Histoembryology, Kunming Medical University, Kunming, 650500, China.
Dept. of Basic Medical, Medical College, Yunnan College of Business Management, Kunming, 650000, China.
Neuromolecular Med. 2020 Sep;22(3):401-410. doi: 10.1007/s12017-020-08598-z. Epub 2020 Apr 6.
Reactive oxygen species (ROS) are continuously produced as byproducts of aerobic metabolism. Oxidative stress (OS) plays an important role in the occurrence of several neurodegenerative diseases as well as aging because of the accumulation of ROS. Gnaq is a member of G protein α subunits. It has been reported that the expression level of Gnaq in the mouse forebrain cortex was significantly decreased with age in our previous study; therefore, we supposed that Gnaq contributes to attenuate the OS. In this study, we generated a Gnaq-overexpression cell using gene recombinant technique and lentivirus transfection technique in a neuron-like PC12 cell, and investigated whether Gnaq had antioxidant effects in PC12 cells treated with HO. The viability of cells, concentration of ROS, Nrf2 nuclear translocation, expression of antioxidant enzymes, activation of NF-κB and apoptosis were compared between Gnaq-PC12 cells and Vector-PC12 cells. Results showed that, compared with Vector-PC12 cells, the antioxidative ability of Gnaq-PC12 cells was significantly improved, while the ROS level in Gnaq-PC12 cells was significantly decreased. Nrf2 nuclear translocation was up-regulated and NF-κB nuclear translocation was down-regulated in Gnaq-PC12 cells after HO treatment. The results suggest that Gnaq plays a crucial role in neuroprotection in PC12 cells. A possible mechanism for this would be that the overexpressed Gnaq enhances the antioxidative effect mediated by Nrf2 signal pathway and inhibits the cellular damaging effect through NF-κB signal pathway.
活性氧（ROS）是有氧代谢的副产品，会持续产生。氧化应激（OS）在几种神经退行性疾病以及衰老的发生中起着重要作用，因为 ROS 会积累。Gnaq 是 G 蛋白α亚基的成员。在我们之前的研究中，有报道称 Gnaq 在小鼠大脑皮质中的表达水平随年龄增长而显著下降；因此，我们推测 Gnaq 有助于减轻 OS。在这项研究中，我们使用基因重组技术和慢病毒转染技术在神经元样 PC12 细胞中生成了 Gnaq 过表达细胞，并研究了 Gnaq 是否对 HO 处理的 PC12 细胞具有抗氧化作用。比较了 Gnaq-PC12 细胞和 Vector-PC12 细胞之间细胞活力、ROS 浓度、Nrf2 核易位、抗氧化酶表达、NF-κB 激活和细胞凋亡的差异。结果表明，与 Vector-PC12 细胞相比，Gnaq-PC12 细胞的抗氧化能力显著提高，而 Gnaq-PC12 细胞中的 ROS 水平显著降低。HO 处理后，Gnaq-PC12 细胞中 Nrf2 核易位上调，NF-κB 核易位下调。这些结果表明，Gnaq 在 PC12 细胞的神经保护中起着至关重要的作用。其可能的机制是，过表达的 Gnaq 增强了 Nrf2 信号通路介导的抗氧化作用，并通过 NF-κB 信号通路抑制细胞损伤效应。
