School of Basic Medical Sciences, Binzhou Medical University, 346# Guanhai Road, Yantai, 264003, China.
World J Microbiol Biotechnol. 2023 Aug 21;39(10):284. doi: 10.1007/s11274-023-03710-4.
Reactive oxygen species (ROS) can regulate the occurrence of autophagy, and effective control of the balance between ROS and autophagy may be an important strategy for Helicobacter pylori induced gastric-related diseases. In this study, infection with H. pylori led to a lower level of ILK phosphorylation and increased ROS generation. Knockdown of ILK enhanced total ROS generation, and upregulated NADPH oxidase (NOX) subunit p22-phox levels. Inhibition of NOXs affected total ROS generation. The inhibition of NOX and ROS generation reduced Nrf2 and HO-1 levels, and knockdown of ILK significantly enhanced Nrf2 levels in H. pylori-infected GES-1 cells. Activation of Nrf2 by DMF decreased ROS levels. Therefore, NOX-dependent ROS production regulated by ILK was essential for activation of Nrf2/HO-1 signaling pathways in H. pylori-infected GES-1 cells. Beclin1, ATG5 and LC3B-II levels were higher both in H. pylori-infected and ILK-knockdown GES-1 cells. In NAC-pretreated GES-1 cells infected with H. pylori, the LC3B-II level was decreased compared to that in cells after H. pylori infection alone. Stable low expression of ILK with further knockdown of Beclin1 or ATG5 significantly reduced LC3B-II levels in GES-1 cells, while with the addition of the autophagy inhibitor chloroquine (CQ), LC3B-II and p62 protein levels were both remarkably upregulated. H. pylori accelerated the accumulation of ROS and further led to the induction of ROS-mediated autophagy by inhibiting ILK levels. Together, these results indicate that H. pylori infection manipulates the NOX-ROS-Nrf2/HO-1-ROS loop to control intracellular oxygen stress and further induced ROS-mediated autophagy by inhibiting ILK levels.
活性氧（ROS）可以调节自噬的发生，有效控制 ROS 和自噬之间的平衡可能是幽门螺杆菌诱导的胃相关疾病的重要策略。在这项研究中，幽门螺杆菌感染导致 ILK 磷酸化水平降低，ROS 生成增加。ILK 敲低增强了总 ROS 的生成，并上调 NADPH 氧化酶（NOX）亚基 p22-phox 水平。NOX 的抑制影响总 ROS 的生成。NOX 和 ROS 生成的抑制降低了 Nrf2 和 HO-1 水平，ILK 敲低显著增加了幽门螺杆菌感染的 GES-1 细胞中的 Nrf2 水平。DMF 激活 Nrf2 降低了 ROS 水平。因此，ILK 依赖性 ROS 产生的 NOX 对于幽门螺杆菌感染的 GES-1 细胞中 Nrf2/HO-1 信号通路的激活是必要的。在幽门螺杆菌感染和 ILK 敲低的 GES-1 细胞中，Beclin1、ATG5 和 LC3B-II 的水平均升高。在用 NAC 预处理的 GES-1 细胞中感染幽门螺杆菌后，LC3B-II 水平比单独感染幽门螺杆菌后降低。在 GES-1 细胞中，ILK 的稳定低表达进一步敲低 Beclin1 或 ATG5 可显著降低 LC3B-II 水平，而加入自噬抑制剂氯喹（CQ）后，LC3B-II 和 p62 蛋白水平均显著上调。幽门螺杆菌通过抑制 ILK 水平加速 ROS 的积累，进而诱导 ROS 介导的自噬。综上所述，这些结果表明，幽门螺杆菌感染通过抑制 ILK 水平来操纵 NOX-ROS-Nrf2/HO-1-ROS 循环来控制细胞内氧应激，并进一步诱导 ROS 介导的自噬。
