miR-377-5p靶向IRAK1通过抑制JNK信号通路改善脑缺血再灌注大鼠神经损伤和炎性反应

目的 探究miR-377-5p对脑缺血再灌注(ischemia/reperfusion,I/R)大鼠神经损伤和炎性反应的作用及机制.方法 通过生物信息学预测到miR-377-5p与白介素1受体相关激酶(interleukin-1 receptor-associated kinases,IRAK1)靶向关系.SD大鼠随机分为sham组、I/R组、miR-NC组、pc-NC组、miR-377-5p mimic组、pc-IRAK1组、miR-377-5p mimic+pc-IRAK1组.将转染物注射到右脑室中,并构建大鼠脑I/R模型.神经功能评分和脑含水量测定;TUNEL(terminal deoxynucleotidyl transferase dUTP nick end la-beling)染色观察海马神经细胞凋亡;酶联免疫吸附试验(enzyme-linked immunosorbent assay,ELISA)检测大鼠血清中肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)、白介素-6(interleukin-6,IL-6)、IL-1 E含量;蛋白质印迹检测IRAK1和p-c-Jun N-末端激酶2(c-Jun N-terminal kinase 2,JNK2)/JNK2、p-JNK1/JNK1蛋白质水平.结果 miR-377-5p与IRAK1靶向结合,且miR-377-5p过表达可靶向下调IRAK1表达.共转染miR-377-5p mimic和pc-IRAK1后,神经功能评分和脑含水量降低,海马神经细胞凋亡率显著降低,血清中TNF-D、IL-1 E、IL-6含量显著降低,脑组织中p-JNK2/JNK2、p-JNK1/JNK1蛋白质水平显著下调.结论 miR-377-5p靶向IRAK1通过抑制JNK信号通路改善脑缺血再灌注大鼠神经损伤和炎性反应.

miR-377-5p Ameliorates Nerve Injury and Inflammatory Response in Rats with Cerebral Ischemia-Reperfusion by Targeting IRAK1 Through Inhibiting JNK Signaling Pathway

Objective To investigate the effect and mechanism of miR-377-5p on nerve injury and inflammatory response in rats with cerebral ischemia-reperfusion(I/R).Methods The targeting relationship miR-377-5p and interleukin-1 receptor-associated kinases(IRAK1)were predicted by bioinformatics,SD rats were randomly divided into sham group,I/R group,miR-NC group,pc-NC group,miR-377-5p mimic group,pc-IRAK1 group,and miR-377-5p mimic+pc-IRAK1 group.Before constructing the rat middle brain I/R model by online embolization,the transfection was injected into the right ventricle.The apoptosis of hippocampal neurons was observed by TUNEL(terminal deoxynucleotidyl transferase dUTP nick end labeling)staining,tumor necrosis factor-α(TNF-α),interleukin-6(IL-6)and IL-1 Elevels in rat serum were detected by enzymelinked immunosorbent assay(ELISA),the protein expression levels of IRAK1 and p-JNK2/JNK2 and p-JNK1/JNK1 were detected by Western blot.Results miR-377-5p and IRAK1 had targeted binding sites in the 3c-UTR region,and miR-377-5p overexpression targeted down-regulation of IRAK1 expression.Compared with the model group,the neurological function score and brain water content of rats in the miR-377-5p mimic group were significantly decreased,the hippocampal tissue injury was significantly alleviated,the apoptosis rate of hippocampal neurons was significantly decreased,the contents of TNF-D,IL-1 Eand IL-6 in the serum were significantly decreased,and the expression of p-JNK2/JNK2 and p-JNK1/JNK1 protein in the brain tissue was significantly down-regulated(P<0.01);the neurological function score and brain water content of rats in the pc-IRAK1 group were significantly increased,the hippocampal tissue injury was significantly aggravated,the apoptosis rate of hippocampal neurons was significantly increased,the contents of TNF-D,IL-1 Eand IL-6 in the serum were significantly increased,and the expression of p-c-Jun N-termi-nal kinase 2(JNK2)/JNK2 and p-JNK1/JNK1 protein in the brain tissue was significantly up-regulated(P<0.01).Co-transfection of miR-377-5p mimic and pc-IRAK1 reversed the above effects of miR-377-5p mimic on cerebral I/R rats(P<0.01).Conclusion miR-377-5p ameliorates nerve injury and inflammatory response in rats with cerebral ischemia-reperfusion by targeting IRAK1 through inhibiting JNK signaling pathway.