Jiangsu Key Laboratory of Neuropsychiatric Diseases Research and College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu, 215021, China.
College of Pharmaceutical Sciences and the Collaborative Innovation Center for Brain Science, Soochow University, Suzhou, China.
Cell Death Dis. 2018 Jan 9;9(1):11. doi: 10.1038/s41419-017-0014-7.
MicroRNAs play an essential role in stroke pathology. Here, we investigated the role of a newly identified microRNA, miR-3473b, in stroke pathology. The expression of miR-3473b was upregulated in the cortex and striatum in mice following transient middle cerebral artery occlusion (MCAO). Intracerebroventricular injection of the miR-3473b antagomir prior to MCAO remarkably attenuated ischemia-induced expression of miR-3473b and pro-inflammatory factors in the ischemic brain and decreased infarct volumes in mice following MCAO. Using in vitro approaches, we showed that the miR-3473b antagomir reduced the mRNA and protein levels of pro-inflammatory factors (iNOS, COX-2, TNF-α, and IL-6) in BV2 microglial cells subjected to LPS stimulation. The miR-3473b antagomir also decreased the expression of pro-inflammatory factors in BV2 cells activated with conditioned medium collected from oxygen-glucose deprivation (OGD)-treated neurons. Suppressor of cytokine signaling 3 (SOCS3), a physiological regulator of innate and adaptive immunity, was predicted to be a potential target of miR-3473b. We verified that the miR-3473b mimic decreased SOCS3 expression in BV2 cells. Meanwhile, the miR-3473b antagomir significantly increased both SOCS3 mRNA and protein levels in the BV2 cells treated with LPS as well as in the ischemic brain. By using the dual luciferase assay, we further showed that the 3'-untranslational region of SOCS3 was directly targeted by miR-3473b. In conclusion, induction of miR-3473b, which is likely targeted to SOCS3, contributes to stroke pathogenesis by enhancing post-stroke neuroinflammation injury.
微小 RNA 在中风病理中发挥着重要作用。在这里，我们研究了一种新鉴定的微小 RNA，miR-3473b，在中风病理中的作用。短暂性大脑中动脉闭塞 (MCAO) 后，miR-3473b 在皮层和纹状体中的表达上调。MCAO 前，脑室内注射 miR-3473b 反义寡核苷酸可显著减弱缺血诱导的 miR-3473b 和缺血性脑内促炎因子的表达，并降低 MCAO 后小鼠的梗死体积。通过体外方法，我们表明 miR-3473b 反义寡核苷酸可降低 LPS 刺激的 BV2 小胶质细胞中促炎因子（iNOS、COX-2、TNF-α和 IL-6）的 mRNA 和蛋白水平。miR-3473b 反义寡核苷酸还降低了来自氧葡萄糖剥夺 (OGD) 处理神经元的条件培养基激活的 BV2 细胞中促炎因子的表达。细胞因子信号转导抑制因子 3 (SOCS3) 是先天和适应性免疫的生理调节剂，被预测为 miR-3473b 的潜在靶标。我们验证了 miR-3473b 模拟物降低了 BV2 细胞中的 SOCS3 表达。同时，miR-3473b 反义寡核苷酸显著增加了 LPS 处理以及缺血性脑内的 BV2 细胞中的 SOCS3 mRNA 和蛋白水平。通过双荧光素酶报告基因实验，我们进一步表明 SOCS3 的 3'-非翻译区直接被 miR-3473b 靶向。总之，诱导 miR-3473b，可能靶向 SOCS3，通过增强中风后的神经炎症损伤，导致中风发病机制。
