METHODS: Human microvascular endothelial cell-1 (HMEC-1) was cultured under normal conditions (C), hypoxia(H), and hypoxia preconditioning (HPC), followed by the isolation of culture medium (CM). SY5Y cell incubated with the isolated CM from HMEC-1 was exposed to oxygen-glucose deprivation (OGD). The DNA methyltransferases (DNMTs), global methylation level, miR-126 and its promotor DNA methylation level in HMEC-1 were measured. The cell viability and cell injury in SY5Y were detected.
RESULTS: HPC decreased DNMTs level and global methylation level as well as increased miR-126 expression in HMEC-1. CM from HPC treated HMEC-1 also relieved SY5Y cell damage, while CM from HMEC-1 which over-expression of miR-126 can reduce injury in SY5Y under OGD condition.
CONCLUSIONS: These findings indicate EC may secrete molecules, such as miR-126, to execute neuroprotection induced by HPC through regulating the expression of DNMTs.
方法:在正常条件下培养人微血管内皮细胞-1(HMEC-1)(C),缺氧(H),和缺氧预处理(HPC),然后分离培养基(CM)。将与来自HMEC-1的分离的CM一起孵育的SY5Y细胞暴露于氧-葡萄糖剥夺(OGD)。DNA甲基转移酶(DNMT),全局甲基化水平,测量HMEC-1中miR-126及其启动子DNA甲基化水平。检测SY5Y中的细胞活力和细胞损伤。
结果:HPC降低了HMEC-1中的DNMT水平和整体甲基化水平,并增加了miR-126的表达。CM从HPC处理的HMEC-1也减轻了SY5Y细胞损伤,而来自HMEC-1的过表达miR-126的CM可以减轻SY5Y在OGD条件下的损伤。
结论:这些发现表明EC可能分泌分子,例如miR-126,通过调节DNMT的表达来执行HPC诱导的神经保护。