Electroacupuncture Promotes Angiogenesis in Mice with Cerebral Ischemia by Inhibiting miR-7

Objective To observe the angiogenesis effect of electroacupuncture(EA)at Shuigou acupoint(GV 26)in the treatment of cerebral ischemia,and explore the value of miRNA-7(miR-7)in it.Methods First,48 mice were randomly divided into sham operation,middle cerebral artery occlusion(MCAO)model,and EA treatment groups.Then 9 mice were divided into carrier control group,miR-7 knockout group and miR-7 overexpression group(n=3 each group).Finally,20 mice were divided into model and carrier control group,model and miR-7 knockout group,EA treatment and carrier control group and EA treatment and miR-7 overexpression group,with 3–6 mice in each group.The MCAO model was established in the MCAO and EA groups.Neurological deficit score and 2,3,5-triphenyltetrazolium chloride(TTC)staining were used to evaluate the severity of cerebral ischemia.Hematoxylin-eosin staining was used to describe basic pathological changes.Immunohistochemistry was used to quantify cerebral microvessel density.Real-time PCR and Western blot were used to detect the expression of miR-7 and its downstream target genes Krüppel-like factor 4/vascular endothelial growth factor(KLF4/VEGF)and angiopoietin-2(ANG-2)in the ischemic cerebral cortex.Results After EA,neurological deficit scores and infarction volumes decreased,and the density of cerebral microvessels increased.In the MCAO group,miR-7 expression was higher than that in the sham group(P<0.01).After EA at GV 26,miR-7 expression decreased(P<0.01)and the expression of downstream target genes KLF4/VEGF and ANG-2 increased as compared with the MCAO group(P<0.01).After EA combined with overexpression of miR-7,the expression of downstream target genes KLF4/VEGF and ANG-2 decreased compared to the control EA group(P<0.01).After miR-7 knockdown,the expression of KLF4/VEGF and ANG-2 increased(P<0.05 or P<0.01).Conclusions EA could promote angiogenesis in MCAO mice likely by inhibiting the expression of miR-7 and relieving inhibition of downstream target genes KLF4/VEGF and ANG-2.