BACKGROUND Inflammation and apoptosis are considered to be two main factors affecting ischemic brain injury and the subsequent reperfusion damage. MiR-19a-3p has been reported to be a possible novel biomarker in ischemic stroke. However, the function and molecular mechanisms of miR-19a-3p remain unclear in cerebral ischemia/reperfusion (I/R) injury. METHODS The I/R injury model was established in vivo by middle cerebral artery occlusion/reperfusion (MCAO/R) in rats and in vitro by oxygen-glucose deprivation and reperfusion (OGD/R) induced SH-SY5Y cells. The expression of miR-19a-3p was determined by reverse transcription quantitative PCR. The infarction volumes, Neurological deficit scores, apoptosis, cell viability, pro-inflammatory cytokines and apoptosis were evaluated using Longa score, Bederson score, TTC, TUNEL staining, CCK-8, ELISA, flow cytometry assays. Luciferase reporter assay was utilized to validate the target gene of miR-19a-3p. RESULTS We first found miR-19a-3p was significantly up-regulated in rat I/R brain tissues and OGD/R induced SH-SY5Y cells. Using the in vivo and in vitro I/R injury model, we further demonstrated that miR-19a-3p inhibitor exerted protective role against injury to cerebral I/R, which was reflected by reduced infarct volume, improved neurological outcomes, increased cell viability, inhibited inflammation and apoptosis. Mechanistically, miR-19a-3p binds to 3'UTR region of IGFBP3 mRNA. Inhibition of miR-19a-3p caused the increased expression of IGFBP3 in OGD/R induced SH-SY5Y cells. Furthermore, we showed that IGFBP3 overexpression imitated, while knockdown reversed the protective effects of miR-19a-3p inhibitor against OGD/R-induced injury. CONCLUSIONS In summary, our findings showed miR-19a-3p regulated I/R-induced inflammation and apoptosis through targeting IGFBP3, which might provide a potential therapeutic target for cerebral I/R injury.

中文翻译：

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通过体内和体外靶向IGFBP3，miR-19a-3p的抑制作用可降低脑缺血/再灌注损伤。

背景技术炎症和细胞凋亡被认为是影响缺血性脑损伤和随后的再灌注损伤的两个主要因素。据报道，MiR-19a-3p是缺血性卒中中可能的新型生物标志物。但是，miR-19a-3p在脑缺血/再灌注（I / R）损伤中的功能和分子机制仍不清楚。方法通过大鼠大脑中动脉闭塞/再灌注（MCAO / R）建立体内I / R损伤模型，通过氧葡萄糖剥夺和再灌注（OGD / R）诱导的SH-SY5Y细胞体外建立I / R损伤模型。通过逆转录定量PCR确定miR-19a-3p的表达。使用Longa评分，Bederson评分，TTC，TUNEL染色，CCK-8，ELISA，ACC评估了梗死体积，神经功能缺损评分，细胞凋亡，细胞活力，促炎细胞因子和凋亡。流式细胞仪测定。萤光素酶报告基因分析被用于验证miR-19a-3p的靶基因。结果我们首先发现miR-19a-3p在大鼠I / R脑组织和OGD / R诱导的SH-SY5Y细胞中明显上调。使用体内和体外I / R损伤模型，我们进一步证明miR-19a-3p抑制剂对脑I / R损伤具有保护作用，这表现为梗死面积减少，神经系统转归改善，细胞活力增强，抑制炎症和细胞凋亡。从机制上讲，miR-19a-3p与IGFBP3 mRNA的3'UTR区结合。miR-19a-3p的抑制导致OGD / R诱导的SH-SY5Y细胞中IGFBP3的表达增加。此外，我们表明，IGFBP3的过量表达被模仿，而敲低则逆转了miR-19a-3p抑制剂对OGD / R诱导的损伤的保护作用。