【摘要】 目的探讨微小RNA-146a（miR-146a）靶向调控信号转导与转录激活子1（STAT1）的表达,以及其在颈动脉粥样硬化（CAS）血管内皮细胞中的功能。方法将4月龄雄性新西兰白兔按随机数字表法分成4组,每组10只:假手术组（sham组）、模型组、miR-146a-mimics-NC组（对照组）和miR-146a-mimics组（实验组）。分别尾静脉注射Lipofectamine^TM RNAiMAX和miR-146a-mimics-NC、miR-146a-mimics的混合液到对照组和实验组兔体内,sham组和模型组注射等剂量的生理盐水;采用L-蛋氨酸饲料喂养配合颈总动脉球囊损伤法构建CAS模型,sham组只剥离颈内动脉,不进行球囊扩张和结扎。4周后处死动物留取标本,HE染色、qRT-PCR、Western blot检测各组兔CAS病理改变、miR-146a和STAT1蛋白的mRNA表达、Janus激酶2（JAK2）和磷酸化STAT1（p-STAT1）的表达水平。分别提取标本中颈动脉的血管内皮细胞进行培养,EdU标记、Transwell小室、小管形成、TUNEL染色检测各组细胞的增殖能力、迁移能力、小管生成能力和凋亡。荧光素酶报告基因分析miR-146a和STAT1的调控关系。结果与sham组相比,模型组兔颈动脉标本中miR-146a的表达水平明显降低,而STAT1的mRNA、JAK2和p-STAT1的表达水平明显升高,内皮细胞的增殖能力、迁移能力、小管生成能力降低,细胞凋亡率升高,CAS病理明显;与模型组和对照组相比,实验组兔颈动脉标本中miR-146a的表达水平明显升高,而STAT1的mRNA、JAK2和p-STAT1的表达水平明显下降,内皮细胞的增殖能力、迁移能力、小管生成能力增强,细胞凋亡率下降,CAS病理明显好转,差异均有统计学意义（均为P<0.05）。荧光素酶报告基因分析证实miR-146a与STAT1靶向结合。结论 MiR-146a能靶向调控STAT1的表达,过表达miR-146a能够抑制STAT1的表达,发挥其保护颈动脉内皮细胞的功能。更多还原

【Abstract】 Objective To investigate the role of microRNA-146 a（miR-146 a） in regulating the biological characteristics of vascular endothelial cells in carotid atherosclerosis（CAS） by targeting the expression of signal transducer and activator of transcription 1（STAT1）. Methods Four-month-old male New Zealand white rabbits were randomly divided into 4 groups, according to the random number table method, 10 in each group: sham operation group（sham group）, model group, miR-146 a-mimics-NC group（control group） and miR-146 a-mimics group（experimental group）. A mixture of Lipofectamine^TM RNAiMAX and miR-146 a-mimics-NC, miR-146 a-mimics was administered to rabbits in the control group and the experimental group through tail vein respectively, and the rabbits in the sham group and the model group were injected with the same dose of normal saline. A rabbit model of CAS was constructed by feeding L-methionine feed and carotid artery balloon injury. The rabbits in the sham operation group only removed the internal carotid artery and did not perform balloon dilation and ligation. After 4 weeks, the animals were sacrificed and the specimens were taken. HE staining, qRT-PCR and Western blot were used to detect the pathological changes of CAS, the expression of miR-146 a and STAT1 mRNA, and the expression levels of Janus kinase 2（JAK2） and phosphorylated STAT1（p-STAT1）. Rabbit carotid endothelial cells were cultured in the specimens. EdU labeling, Transwell chamber, tubule formation, TUNEL staining were used to detect the proliferative capacity, migration ability, tubule formation ability and apoptosis of each group of cells. Luciferase reporter gene analysis showed the regulatory relationship between miR-146 a and STAT1.Results Compared with the sham group, the expression level of miR-146 a in the carotid artery samples in the model group was significantly decreased, while the expression levels of STAT1 mRNA, JAK2 and p-STAT1 were significantly increased. The proliferative capacity, migration ability, tubule formation ability of endothelial cells decreased, the apoptosis rate increased, and the pathology of CAS was obvious. Compared with the model group, the expression level of miR-146 a in the carotid artery samples in the experimental group was significantly increased, while the expression levels of STAT1 mRNA, JAK2 and p-STAT1 were significantly decreased. The proliferative capacity, migration ability, tubule formation ability of endothelial cells increased, the apoptosis rate decreased, and the pathology of CAS was obvious improved. The differences were statistically significant（all P<0.05）. Luciferase reporter gene analysis demonstrated that miR-146 a targets to STAT1. Conclusions MiR-146 a can regulate the expression of STAT1 and overexpress miR-146 a, which can inhibit the expression of STAT1 and protect the function of carotid artery endothelial cells.更多还原