The Angiogenesis Effects of Electro-acupuncture Treatment via Exosomal miR-210 in Cerebral Ischemia-Reperfusion Rats

BACKGROUND: Acupuncture has been recommended as an alternative and complementary therapy for preventing and treating cerebral ischemia by the World Health Organization (WHO) for years. However, the mechanisms remain unclear. Accumulating evidence has shown that acupuncture can promote angiogenesis to attenuate brain damage after ischemic stroke. In recent years, exosome- carried microRNAs (miRNAs) activated by acupuncture have proven effective in regulating pathological changes. We, therefore, investigated whether electro-acupuncture (EA) enhanced angiogenesis in cerebral stroke via exosome-carried miR-210. METHODS: We extracted and identified the exosomes from the serum of MCAO with EA treatment and injected them into MCAO rats for further observation. Simultaneously, miR-120 siRNA and HIF-1α inhibitor were transfected. Then, we evaluated the volume of infarction, pathological changes, and expression levels of angiogenic related factors of each group of rats by TTC and HE staining, transmission electron microscope (TEM), western blot, and quantitative PCR (qPCR). RESULTS: Compared with the MCAO group, EA-Exosome (EA-EXO) treatment significantly decreased the infarct volume and the pathological damage, but miR-210 siRNA or HIF-1α inhibitor reversed the protective outcomes induced by EA-EXO. Moreover, EA-EXO treatment upregulated miR-210 and increased CD34, HIF-1α, VEGF, Notch1 protein, and mRNA expressions compared to the MCAO group. MiR-210 siRNA or HIF-1α inhibitor treatments both down-regulated those angiogenic related proteins and mRNAs. CONCLUSION: EA treatment could activate the HIF-1α/VEGF/Notch 1 signal pathway to facilitate angiogenesis after ischemic stroke via exosomal miR-210.