miR-137通过调控血红素铁输出蛋白FLVCR、BCRP对大鼠I/R损伤的保护作用

Protective effects of miR-137 on cerebral ischemia reperfusion injury by regulating heme iron export protein FLVCR/BCRP in rats

目的探讨大鼠脑缺血/再灌注(I/R)后血红素铁输出蛋白猫白血病病毒C亚组受体(FLVCR)、乳腺癌抗性蛋白(BCRP)的表达变化及miR-137对其表达的调控作用。方法选取SD大鼠60只,随机分为假手术(SO)组、模型(MCAO/R)组、miR-137模拟物(Mimic)组、miR-137模拟对照(Mimic对照)组、miR-137抑制物(Inhibitor)组、miR-137抑制对照(Inhibitor对照)组,每组10只。采用线栓法制作大鼠脑缺血再灌注(MCAO/R)模型,分别于再灌注后12、24 h取材。通过qRT-PCR测定大鼠脑组织FLVCR、BCRP及miR-137的mRNA表达,免疫组化检测FLVCR、BCRP蛋白的表达水平。结果MCAO/R组大鼠神经功能缺损评分显著升高(P<0.01),Mimic组评分显著下降(P<0.01),Inhibitor组评分显著升高(P<0.05)。MCAO/R组miR-137 mRNA表达水平显著降低(P<0.05),与Mimic对照组同时间比较,Mimic组miR-137 mRNA表达水平显著升高(P<0.01),且24 h升高更显著(P<0.05);与Inhibitor对照组同时间比较,Inhibitor组miR-137 mRNA表达水平显著降低(P<0.05),且24 h降低更显著(P<0.05)。与SO组比较,MCAO/R组FLVCR mRNA及蛋白表达水平均显著降低(P<0.05);与Mimic对照组比较,Mimic组FLVCR mRNA及蛋白表达水平在12 h显著升高(P<0.05),24 h最高(P<0.05);与Inhibitor对照组比较,Inhibitor组FLVCR mRNA及蛋白表达水平降低(P<0.01),在24 h降低更明显(P<0.05)。与SO组比较,MCAO/R组BCRP mRNA及蛋白表达水平显著降低(P<0.05);与Mimic对照组比较,Mimic组BCRP mRNA及蛋白表达水平在12 h显著升高(P<0.01),24 h最高(P<0.05);与Inhibitor对照组比较,Inhibitor组BCRP mRNA及蛋白表达水平显著降低(P<0.01)。结论miR-137过表达可能促进FLVCR和BCRP的表达以保护大鼠脑缺血再灌注损伤。

Objective To study the heme ferritin feline-exporting protein feline leukemia virus subgroup C receptor(FLVCR)and the human breast cancer resistance protein(BCRP)after cerebral ischemia/reperfusion(I/R)in rats changes in expression and the regulatory effect of miR-137 on its expression.Methods 60 SD rats were randomly divided into sham operation group(SO)and model group(MCAO/R),miR-137 mimic group(Mimic),miR-137 mimic control group(Mimic control),miR-137 inhibitor group(Inhibitor),miR-137 inhibitor control group(Inhibitor control).Rat model of middle cerebral artery occlusion-reperfusion(MCAO/R)was established by threading method,rats in each group were sampled 12h and 24h after reperfusion(n=10).The mRNA expression of FLVCR,BCRP and miR-137 in rat brain tissue was measured by qRT-PCR,and immunohistochemical was used to observe and evaluate the expression levels of FLVCR,BCRP proteins.Results Rat neurological deficit score:MCAO/R group score was significantly increased(P<0.01);The score of the Mimic group decreased significantly(p<0.01);The score of the Inhibitor group was significantly elevated(P<0.05).miR-137 mRNA expression level:the mRNA level of the MCAO/R group was significantly reduced(P<0.05);compared with the Mimic control group at the same time,the mRNA level in the Mimic group was significantly increased(P<0.01)and 24h the elevation was more pronounced(P<0.05);compared with the Inhibitor control group at the same time,the mRNA level of the Inhibitor group was significantly reduced(P<0.05),and the 24h decrease was more significant(P<0.05).FLVCR mRNA and protein expression levels:compared with the SO group,the expression level of the MCAO/R group was significantly reduced(P<0.05);compared with the Mimic control group,the expression level of the Mimic group was significantly increased at 12h(P<0.05),24h maximum(P<0.05);compared with the Inhibitor control group,the expression level of the Inhibitor group decreased(P<0.01)at 24h the decrease is more pronounced(P<0.05).BCRP mRNA and protein expression levels:compared with the SO group,the expression level of MCAO/R group was significantly reduced(P<0.05);compared with the Mimic control group,the expression level of the Mimic group was significantly increased at 12h(P<0.01),at 24 hours highest(P<0.05);compared with the Inhibitor control group,the expression level of the Inhibitor group was significantly reduced(P<0.01).Conclusion miR-137 overexpression may promote the expression of FLVCR and BCRP for protection cerebral ischemia and reperfusion injury in rats.