Abstract：
BACKGROUND: Endothelial cells (ECs) can confer neuroprotection by secreting molecules. This study aimed to investigate whether DNA methylation contributes to the neuroprotective gene expression induced by hypoxia preconditioning (HPC) in ECs and to clarify that the secretion of molecules from HPC ECs may be one of the molecular mechanisms of neuroprotection.
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.
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.
摘要：
背景：内皮细胞（ECs）可以通过分泌分子赋予神经保护。本研究旨在探讨DNA甲基化是否有助于缺氧预处理（HPC）诱导ECs中神经保护基因的表达，并阐明HPCECs分泌分子可能是神经保护的分子机制之一。
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。
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。
