Zhao Dong, Deng Shu-Cai, Ma Yi, Hao Yong-Hong, Jia Zhan-Hua
Department of Spine Surgery, Tianjin Hospital, Tianjin, China.
Neuroreport. 2018 May 23;29(8):655-660. doi: 10.1097/WNR.0000000000001013.
This study aimed to examine the role of miR-221 in inflammatory response and apoptosis of neuronal cells after spinal cord ischemia/reperfusion (I/R) injury. Blood samples were obtained from 20 I/R patients and that of 20 healthy individuals were used as a control. AGE1.HN and SY-SH-5Y neuronal cell lines subjected to oxygen-glucose deprivation (OGD) stress were used in cell experiments. Real-time PCR and western blot were used to evaluate the expression of miR-221, tumor necrosis factor-α, and TNFAIP2. TUNEL assay analyzed cell apoptosis. I/R patients had lower serum levels of miR-221 than healthy controls. In OGD-AGE1.HN and SY-SH-5Y cells, miR-221 was significantly downregulated and TNFAIP2 mRNA and protein were upregulated; meanwhile, both proinflammatory cytokine tumor necrosis factor-α and anti-inflammation cytokine interleukin-6 were elevated and the percentage of apoptotic cells was increased. This inflammatory response and cell apoptosis induced by OGD stress were attenuated by miR-221 overexpression and enhanced by miR-221 knockdown. TNFAIP2 is a target gene for miR-221 and could be regulated negatively by the miR-221 mimic or the miR-221 inhibitor with or without OGD stress. Accordingly, TNFAIP2 overexpression reversed the inflammatory response and cell apoptosis induced by miR-221 under OGD stress. Downregulation of miR-221 occurs in spinal cord I/R injury and in cell lines subjected to oxygen-glucose deprivation. miR-221 regulates the inflammatory response and apoptosis of neuronal cells through its impact on TNFAIP2.
本研究旨在探讨miR-221在脊髓缺血/再灌注（I/R）损伤后神经元细胞炎症反应和凋亡中的作用。采集了20例I/R患者的血样，并以20例健康个体的血样作为对照。细胞实验采用了经受氧糖剥夺（OGD）应激的AGE1.HN和SY-SH-5Y神经元细胞系。采用实时荧光定量PCR和蛋白质印迹法评估miR-221、肿瘤坏死因子-α和TNFAIP2的表达。TUNEL法分析细胞凋亡情况。I/R患者血清miR-221水平低于健康对照。在OGD处理的AGE1.HN和SY-SH-5Y细胞中，miR-221显著下调，TNFAIP2 mRNA和蛋白上调；同时，促炎细胞因子肿瘤坏死因子-α和抗炎细胞因子白细胞介素-6均升高，凋亡细胞百分比增加。OGD应激诱导的这种炎症反应和细胞凋亡通过miR-221过表达而减弱，通过miR-221敲低而增强。TNFAIP2是miR-221的靶基因，无论有无OGD应激，miR-221模拟物或miR-221抑制剂均可对其进行负调控。因此，TNFAIP2过表达逆转了OGD应激下miR-221诱导的炎症反应和细胞凋亡。脊髓I/R损伤以及经受氧糖剥夺的细胞系中均出现miR-221下调。miR-221通过影响TNFAIP2来调节神经元细胞的炎症反应和凋亡。
