微小RNA-223对急性脑梗死大鼠神经功能保护作用的研究

Protective effect of microRNA-223 on neurological function in rats with acute cerebral infarction

目的探讨微小RNA(miR)-223对急性脑梗死大鼠神经保护作用。方法清洁级雄性健康SD大鼠随机分为假手术组(S组)、模型组(M组)、对照序列组(NC组)和miR-223模拟物组(miR组),每组12只,构建缺血-再灌注大鼠模型,S组于缝皮后10 min时经侧脑室注入10μL的0.9%氯化钠注射液,M组、NC组和miR组于恢复血流灌注前15 min,以同样的方法分别将等量0.9%氯化钠注射液、含5 nmol对照序列或miR-223模拟物的0.9%氯化钠注射液注入。分别于建模后和建模7 d时,采用Zea-Longa评分标准对各组大鼠神经功能评分,酶联免疫吸附试验检测血清中炎症因子水平,TUNEL法检测脑组织中细胞凋亡,实时荧光定量PCR术检测脑组织中miR-223表达。结果M组、NC组和miR组大鼠建模后和建模7 d时神经功能评分均高于S组(F=83.943、87.410,P<0.01),miR组大鼠建模7 d时神经功能评分低于M组和NC组(P<0.01);与S组相比,M组、NC组和miR组大鼠血清中白细胞介素-1β(IL-1β)、白细胞介素-6(IL-6)和肿瘤坏死因子-α(TNF-α)水平升高(F=16.085、52.672、27.393,P<0.01),与M组和NC组相比,miR组大鼠血清中IL-1β、IL-6和TNF-α水平降低(P<0.05);M组、NC组和miR组大鼠脑组织中细胞凋亡指数均高于S组(F=461.821,P<0.01),miR组大鼠脑组织中细胞凋亡指数低于M组和NC组(P<0.05);M组和NC组大鼠脑组织中miR-223表达量低于S组,而miR组高于S组,差异有统计学意义(F=328.334,P<0.01)。结论miR-223可能对脑缺血-再灌注损伤大鼠神经功能有保护作用,机制可能与其抑制炎症反应而减少细胞凋亡有关。

Objective To investigate the protective effect of microRNA(miR)-223 on neurological function in rats with acute cerebral infarction.Methods The clean male healthy SD rats were randomly divided into sham operation group(S group),model group(M group),control sequence group(NC group)and miR-223 mimic group(miR group),12 in each group.The ischemia-reperfusion rat model was constructed.In S group,10μL of normal saline was injected into the lateral ventricle at 10 min after skin suture.In the M group,NC group and miR group,15 min before the reperfusion of blood flow was restored,the same amount of normal saline,the normal saline containing 5 nmol control sequence or miR-223 mimic were injected in the same way.After modeling and 7 days after modeling,the ZeaLonga scoring standard was used to evaluate the neurological function of rats in each group.Enzymelinked immunosorbent assay(ELISA)method was used to detect the levels of inflammatory factors in serum.TUNEL method was used to detect the cell apoptosis in brain tissue.The real-time fluorescence quantitative PCR was used to detect the expression of miR-223 in brain tissue.Results The neurological function scores of rats in the M group,NC group and miR group after modeling and 7 days after modeling were higher than those in the S group(F=83.943,87.410;P<0.01),the neurological function scores of rats at 7 days after modeling in the miR group were lower than those in the M group and NC group(P<0.01).Compared with the S group,the levels of interleukin-1β(IL-1β),interleukin-6(IL-6)and tumor necrosis factor-α(TNF-α)in the serum of rats in the M group,NC group and miR group increased,compared with the M group and NC group,the levels of IL-1β,IL-6 and TNF-αin serum of rats in the miR group were reduced(F=16.085,52.672,27.393;P<0.01).The apoptosis indexes of cells in the brain tissues of rats in the M group,NC group and miR group were higher than that in the S group(P<0.05),and apoptosis index of cells in the brain tissues of rats in the miR group was lower than that in the M group and NC group(F=461.821,P<0.01).The expression levels of miR-223 in the brain tissues of rats in the M group and NC group were lower than that in the S group,while the miR group was higher than the S group,the difference was statistically significant(F=328.334,P<0.01).Conclusion Mi R-223 may have protective effects on the neurological function in rats with cerebral ischemia-reperfusion injury,and the mechanism may be related to its inhibition of inflammation and reduction of cell apoptosis.