Electric Acupuncture Treatment Promotes Angiogenesis in Rats with Middle Cerebral Artery Occlusion Through EphB4/EphrinB2 Mediated Src/PI3K Signal Pathway

Background: Cerebral infarction is one of the most common causes of disability and death worldwide. It is reported that electric acupuncture was able to improve the prognosis of cerebral infarction by promoting angiogenesis. However, the corresponding signal pathways of angiogenesis promotes by electric acupuncture treatment needs to be further explored. Methods: MCAO rat was employed as the animal model, and clopidogrel hydrogen sulfate treatment was set as the positive control. Behaviors of rats, H&E staining, and TTC-staining was used to evaluate the recovery of infarcted brain tissue and nervous function. After that, immunocytochemical and immunofluorescence staining was used to quantify the angiogenesis and compensatory circulation, which including the analysis of microvessel density, field/ microvessel area ratio, and microvessel diameter. Western blot and RT-PCR for the detection of the related signal molecule, PI3K, Src, and EphB4/ephrinB2. Results: The neurologic impairment scores were decreased, and the brain tissue damage that showed with H&E and TTC-staining was relieved by the treatment of electric acupuncture in MCAO rat. The quantification of microvessel density and field/ microvessel area ratio was improved obviously, and the microvessel diameter was decreased which represent the angiogenesis of capillary in day 3 and 7 by the electric acupuncture treatment. We also found that the level of Src and PI3K was increased markedly followed by the up-regulation of EphB4 and EphrinB2 mRNA during the electric acupuncture treatment, and the pre-treatment of Src and/or PI3K inhibitor was able to disturb the angiogenesis of capillary. Conclusions: We proved that electric acupuncture was able to accelerate the recovery of infarcted brain tissue and nervous function in MCAO rat by the promotion of angiogenesis, which was regulated by EphB4/EphrinB2 mediated Src/PI3K signal pathway. Our study provides a potential therapy and theoretical basis for the clinical treatment of cerebral infarction by the use of electric acupuncture.