探讨miR-186-5p调控沉默信息调节因子1/过氧化物酶体增殖物激活受体γ共激活因子1α/Ⅲ型纤连蛋白结构域蛋白5（SIRT1/PGC-1α/FNDC5）信号通路对缺血性脑卒中（IS）小鼠神经功能的影响。

通过大脑中动脉闭塞（MCAO）的方法构建IS小鼠模型，并将小鼠分为模型组、阴性对照组、miR-186-5p抑制剂组、依达拉奉组、miR-186-5p抑制剂+SIRT1抑制剂（EX527）组，每组10只；另取10只小鼠作为假手术组，除不插入线栓外，其余操作同IS小鼠模型。使用Longa评分系统评估神经功能，使用苏木精-伊红（HE）染色及尼氏染色观察神经损伤情况，使用免疫荧光法检测神经元特异性核蛋白（NeuN）和离子化钙结合衔接分子1（Iba-1）的表达情况，使用逆转录聚合酶链反应检测miR-186-5p和Sirt1 mRNA的表达水平，使用蛋白质印迹法检测SIRT1/PGC-1α/FNDC5通路相关蛋白的表达水平，使用双荧光素酶基因报告实验验证靶向关系。2组间的计量资料比较采用独立样本t检验。多组间的计量资料比较采用单因素方差分析，进一步两两比较采用SNK-q检验。

miR-186-5p抑制剂组、依达拉奉组、miR-186-5p抑制剂+EX527组、阴性对照组、模型组和假手术组小鼠的Longa评分分别为（0.86±0.10）、（0.82±0.10）、（1.85±0.22）、（2.09±0.23）、（2.15±0.26）和（0±0）分，SIRT1蛋白相对表达水平分别为0.77±0.08、0.81±0.09、0.49±0.05、0.51±0.06、0.48±0.05和0.85±0.10，PGC-1α蛋白相对表达水平分别为0.51±0.06、0.59±0.06、0.33±0.04、0.29±0.03、0.24±0.03和0.61±0.07，FNDC5蛋白相对表达水平分别为1.11±0.12、1.18±0.12、0.71±0.08、0.69±0.08、0.61±0.07和1.24±0.13；miR-186-5p抑制剂组和阴性对照组的上述指标比较，差异均有统计学意义（q=22.519、11.070、13.688、12.921，P均＜0.001）；miR-186-5p抑制剂+EX527组小鼠的上述指标与miR-186-5p抑制剂组小鼠比较，差异均有统计学意义（q=18.125、11.921、11.199、12.305，P均＜0.001）。模型组小鼠的NeuN阳性细胞数、Sirt1 mRNA相对表达水平和神经细胞数均显著低于假手术组小鼠，Iba-1阳性细胞数和miR-186-5p相对表达水平均显著高于假手术组小鼠，差异均有统计学意义（P均＜0.05）；miR-186-5p抑制剂组和依达拉奉组小鼠的NeuN阳性细胞数、Sirt1 mRNA相对表达水平和神经细胞数均显著高于阴性对照组小鼠，Iba-1阳性细胞数和miR-186-5p表达水平均显著低于阴性对照组小鼠，差异均有统计学意义（P均＜0.05）；miR-186-5p抑制剂+EX527组小鼠的NeuN阳性细胞数、Sirt1 mRNA相对表达水平和神经细胞数均显著低于miR-186-5p抑制剂组小鼠，Iba-1阳性细胞数显著高于miR-186-5p抑制剂组小鼠，差异均有统计学意义（P均＜0.05）。

抑制miR-186-5p表达可以改善IS小鼠的神经功能，其机制与靶向调节SIRT1/PGC-1α/FNDC5通路有关。

To investigate the effect of miR-186-5p regulation of the silent information regulator 1/peroxisome proliferator-activated receptor γ coactivator-1α/fibronectin type Ⅲ domain-containing protein 5 (SIRT1/PGC-1α/FNDC5) pathway on the neurological function of mice with ischemic stroke (IS).

An IS mouse model was established using the middle cerebral artery occlusion (MCAO) method, and mice were divided into five groups: model group, negative control group, miR-186-5p inhibitor group, edaravone group, and miR-186-5p inhibitor + SIRT1 inhibitor (EX527) group, with 10 mice in each group. Additionally, 10 mice were used as a sham operation group, undergoing the same procedures as the IS model group except for the absence of filament insertion. The neurological function was evaluated using the Longa scoring system; the condition of nerve injury was observed by hematoxylin-eosin and Nissl staining; the expression of neuron-specific nuclear protein (NeuN) and ionized calcium-binding adapter molecule 1 (Iba-1) was analyzed by immunofluorescence; the expression levels of miR-186-5p and Sirt1 mRNA were detected by reverse transcription polymerase chain reaction; the expression levels of proteins related to the SIRT1/PGC-1α/FNDC5 pathway were detected by Western blotting; and the targeting relationship was verified by dual-luciferase reporter assay. The independent samples t-test was used to compare the measurement data between the two groups; one-way ANOVA was used to compare the measurement data among multiple groups, and the SNK-q test was used for further pairwise comparisons.

The Longa scores of the miR-186-5p inhibitor group, the edaravone group, the miR-186-5p inhibitor + EX527 group, the negative control group, the model group, and the sham operation group were 0.86±0.10, 0.82±0.10, 1.85±0.22, 2.09±0.23, 2.15±0.26, and 0±0, respectively; the relative expression levels of SIRT1 protein were 0.77±0.08, 0.81±0.09, 0.49±0.05, 0.51±0.06, 0.48±0.05, and 0.85±0.10, respectively; the relative expression levels of PGC-1α protein were 0.51±0.06, 0.59±0.06, 0.33±0.04, 0.29±0.03, 0.24±0.03, and 0.61±0.07, respectively; the relative expression levels of FNDC5 protein were 1.11±0.12, 1.18±0.12, 0.71±0.08, 0.69±0.08, 0.61±0.07, and 1.24±0.13, respectively. The differences in the above indicators between the miR-186-5p inhibitor group and the negative control group were statistically significant (q=22.519, 11.070, 13.688, 12.921; all P＜0.001). The differences in the above indicators between the miR-186-5p inhibitor + EX527 group and the miR-186-5p inhibitor group were also statistically significant (q=18.125, 11.921, 11.199, 12.305; all P＜0.001). The number of NeuN-positive cells, the relative expression level of Sirt1 mRNA, and the number of nerve cells in the model group were significantly lower than those in the sham operation group, and the number of Iba-1-positive cells and the relative expression level of miR-186-5p in the model group were significantly higher than those in the sham operation group (all P＜0.05). The number of NeuN-positive cells, the relative expression level of Sirt1 mRNA, and the number of nerve cells in the miR-186-5p inhibitor group and the edaravone group were significantly higher than those in the negative control group, while the number of Iba-1-positive cells and the expression level of miR-186-5p were significantly lower than those in the negative control group (all P＜0.05). The number of NeuN-positive cells, the relative expression level of Sirt1 mRNA, and the number of nerve cells in the miR-186-5p inhibitor + EX527 group were significantly lower than those in the miR-186-5p inhibitor group, while the number of Iba-1-positive cells was significantly higher than that in the miR-186-5p inhibitor group (all P＜0.05).

Inhibition of miR-186-5p expression improves neurological function in IS mice, and the underlying mechanism is associated with targeted regulation of the SIRT1/PGC-1α/FNDC5 signaling pathway.