Regulatory mechanism of microRNA-146a in protecting the nerves of rats with cerebral hemorrhage
Objective To investigate the expression of targeted regulation of microRNA-146a(miR-146a)on E-box zinc finger protein 1 gene(ZEB1)and its related molecular mechanisms involved in neuroprotection and autophagy inhibition in a rat model of cerebral hemorrhage.Methods Forty 8-week-old male SD rats were randomly divided into four groups:sham operation group,model group,miR-146a overexpression group and miR-146a underexpression group,with 10 rats in each group.Except for the sham operation group,the other three groups were induced to establish an aneurysmal spontaneous intracerebral hemorrhage rat model using type Ⅶ collagenase.Rats of four groups were fed a high-salt diet for 6 weeks and euthanized after an additional feeding for 20 weeks.Neurological function[modified neurologic severity score(mNSS)]and brain water content were compared among the four groups.FJC staining was used to detect the number of degenerated neurons;TUNEL staining was used to detect apoptosis;hematoxylin-eosin(HE)staining was used to observe pathological chan-ges in brain tissue;quantitative real-time polymerase chain reaction(qRT-PCR)was used to detect the expression of miR-146a and ZEB1 mRNA;Western blot was used to detect the expression of ZEB1,autophagy-related proteins human recombinant autophagy effector protein(Beclin 1)and microtubule-associated protein 1 light chain 3(LC3).Results Compared to the sham surgery group,the model group showed a significant increase in mNSS score,brain water content,the number of degenerated neurons and cell apoptosis rate,and the expression level of miR-146a was significantly decreased,while the expressions of ZEB1 mRNA,as well as ZEB1,Beclin 1and LC3 proteins,were significantly increased in the model group(P＜0.05).Compared to the model group,the miR-146a overexpression group exhibited a significant decrease in mNSS score,brain water content,the number of degenerated neurons and cell apoptosis rate,and the expression level of miR-146a was significantly increased,while the expressions of ZEB1 mRNA,as well as ZEB1,Beclin 1 and LC3 proteins were significantly reduced in the miR-146a overexpression group(P＜0.05).Com-pared to the model group,the miR-146a low-expression group showed a further increase in mNSS score,brain water content,the number of degenerated neurons and cell apoptosis rate,and the ex-pression level of miR-146a was further decreased,while the expressions of ZEB1 mRNA,as well as ZEB1,Beclin 1 and LC3 proteins were further elevated in the miR-146a low-expression group(P＜0.05).Conclusion Upregulating miR-146a can exert neuroprotective effects by targeting and in-hibiting ZEB1 gene and protein expression,as well as regulating autophagy activity.
万方数据
维普
