Can cerebral revascularization prevent hemorrhagic event in moyamoya disease? : Part II; Message from the bench (the effect of encephalomyosynangiosis in modulation of proangiogentic factor expression in rat chronic hypoperfusion model)

초록

OBJECTIVE: Indirect revascularization can be an effective therapeutic tool for chronic cerebral ischemia such as moyamoya disease. However, its exact effect on the neoangiogenesis in the ischemic area has not been known. Particularly, there is still debate in its role for hemorrhagic event prevention. We performed this study to elucidate its effect on the neoangiogenesis in chronic cerebral hypoperfusion at the molecular level and to infer the role of indirect revascularization in the hemorrhagic event prevention in the moyamoya disease. METHODS: Chronic cerebral hypoperfusion injury had been made by occlusion of bilateral internal carotid artery (2ICAO) at a more superior level than the point of origin of the pterygopalatine artery. Male SD rats (6 weeks) were divided into three groups (Sham, 2ICAO, 2ICAO+EMS (encephalomyosynangiosis group)). After one week, the EMS groups received craniectomy and the exposed brain surface was covered with the muscle flap separated from the temporal bone. All rats received intraperitoneal injection of BrdU (50mg/Kg/day) for 5 days consecutively. The animals were sacrificed after 3 weeks of post-2ICAO. We did microfil injection for evaluating vascular connections between temporal muscle and brain in EMS group and did immuno-histochemistry and Western blot analysis (PECAM1, VEGF, HIF, Angiopoietin I and II) for angiogenesis evaluation. RESULTS: EMS group demonstrated a lot of newly formed vessel in the brain-muscle interface area. The PECAM1 positive vessel density increased significantly in the 2ICAO and EMS group compared with the sham group. Interestingly, in the upper part of the cortex, PECAM1 positive vessel numbers decreased in the 2ICAO group and increased in the EMAS group compared with sham group. More interestingly, there were significant increases of vessel numbers that lumen diameter large than 10um in EMS group compared with sham or 2ICAO group. The expression of pro-angiogenic factors (HIF-1, VEGF, and Angiopoi