Zhuang Jingcong, Chen Zhongjie, Cai Pingping, Wang Rong, Yang Qingwei, Li Longling, Yang Huili, Zhu Renjing
Department of Neurology, Zhongshan Hospital Xiamen University, Xiamen, China.
School of Medicine, Xiamen University, Xiamen, China.
Front Cell Neurosci. 2020 Dec 21;14:587747. doi: 10.3389/fncel.2020.587747. eCollection 2020.
This study aimed to explore the molecular regulatory network among microRNA-125b (miR-125b), forkhead box Q1 (FOXQ1), prostaglandin-endoperoxide synthase 2 (PTGS2), and cyclin-dependent kinase 5 (CDK5), as well as their effects on cell apoptosis, neurite outgrowth, and inflammation in Alzheimer disease (AD). Rat embryo cerebral cortex neurons and nerve growth factor-stimulated PC12 cells were insulted by Aβ to construct two AD cellular models. Negative control (NC) inhibitor, miR-125b inhibitor, NC siRNA, FOXQ1 siRNA, PTGS2 siRNA, and CDK5 siRNA were transferred into the two AD cellular models alone or combined. Then, cell apoptosis, neurite outgrowth, proinflammatory cytokines, miR-125b, FOXQ1, PTGS2, and CDK5 expressions were detected. MiR-125b inhibition facilitated neurite outgrowth but suppressed cell apoptosis and proinflammatory cytokines (tumor necrosis factor-α, interleukin 1β, and interleukin 6); meanwhile, it upregulated FOXQ1 but downregulated PTGS2 and CDK5. Furthermore, FOXQ1 inhibition promoted cell apoptosis and proinflammatory cytokines but repressed neurite outgrowth; PTGS2 inhibition achieved the opposite effects; CDK5 inhibition attenuated cell apoptosis, whereas it less affected neurite outgrowth and inflammation. Notably, FOXQ1 inhibition attenuated, whereas PTGS2 inhibition elevated the effect of miR-125b inhibition on regulating neurite outgrowth, cell apoptosis, and proinflammatory cytokines. As for CDK5 inhibition, it enhanced the effect of miR-125b inhibition on regulating cell apoptosis, but less impacted the neurite outgrowth and proinflammatory cytokines. Additionally, PTGS2 inhibition and CDK5 inhibition both reversed the effect of FOXQ1 inhibition on regulating cell apoptosis, neurite outgrowth, and proinflammatory cytokines. In conclusion, targeting miR-125b alleviates AD progression via blocking PTGS2 and CDK5 in a FOXQ1-dependent way.
本研究旨在探索微小RNA-125b（miR-125b）、叉头框Q1（FOXQ1）、前列腺素内过氧化物合酶2（PTGS2）和细胞周期蛋白依赖性激酶5（CDK5）之间的分子调控网络，以及它们对阿尔茨海默病（AD）中细胞凋亡、神经突生长和炎症的影响。用Aβ损伤大鼠胚胎大脑皮质神经元和神经生长因子刺激的PC12细胞，构建两种AD细胞模型。将阴性对照（NC）抑制剂、miR-125b抑制剂、NC小干扰RNA（siRNA）、FOXQ1 siRNA、PTGS2 siRNA和CDK5 siRNA单独或联合转入两种AD细胞模型中。然后，检测细胞凋亡、神经突生长、促炎细胞因子、miR-125b、FOXQ1、PTGS2和CDK5的表达。抑制miR-125b促进神经突生长，但抑制细胞凋亡和促炎细胞因子（肿瘤坏死因子-α、白细胞介素1β和白细胞介素6）；同时，它上调FOXQ1但下调PTGS2和CDK5。此外，抑制FOXQ1促进细胞凋亡和促炎细胞因子，但抑制神经突生长；抑制PTGS2则产生相反的效果；抑制CDK5减弱细胞凋亡，而对神经突生长和炎症的影响较小。值得注意的是，抑制FOXQ1减弱了，而抑制PTGS2增强了miR-125b抑制对调节神经突生长、细胞凋亡和促炎细胞因子的作用。至于抑制CDK5，它增强了miR-125b抑制对调节细胞凋亡的作用，但对神经突生长和促炎细胞因子的影响较小。此外，抑制PTGS2和抑制CDK5均逆转了抑制FOXQ1对调节细胞凋亡、神经突生长和促炎细胞因子的作用。总之，靶向miR-125b通过以FOXQ1依赖的方式阻断PTGS2和CDK5来减轻AD的进展。
