Long noncoding RNA Meg3 mediates ferroptosis induced by oxygen and glucose deprivation combined with hyperglycemia in rat brain microvascular endothelial cells, through modulating the p53/GPX4 axis.
Long noncoding RNA Meg3 mediates ferroptosis induced by oxygen and glucose deprivation combined with hyperglycemia in rat brain microvascular endothelial cells, through modulating the p53/GPX4 axis.
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长非编码RNA Meg3通过调节p53/GPX4轴介导大鼠脑微血管内皮细胞缺氧和缺糖联合高血糖诱导的铁死亡
DOI：
10.4081/ejh.2021.3224
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发表时间：
2021-09-30
期刊：
影响因子：
--
通讯作者：
Ye Z
中科院分区：
文献类型：
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作者：
Chen C;Huang Y;Xia P;Zhang F;Li L;Wang E;Guo Q;Ye Z
与非糖尿病患者相比，糖尿病患者围手术期卒中的风险更高，这主要是由于持续高血糖所致。 LncRNA Meg3被认为是调节缺血性中风的重要介质。然而，Meg3 在糖尿病脑缺血损伤中的功能和调节作用仍不清楚。在本研究中，将大鼠脑微血管内皮细胞（RBMVEC）暴露于缺氧和缺糖（OGD）6小时，然后通过将细胞与不同高浓度的葡萄糖一起孵育24小时进行再灌注，以模拟体外糖尿病脑缺血损伤。结果表明，OGD联合高血糖诱导损伤后，发生了铁死亡和Meg3表达增加的标志事件。然而，所有铁死亡事件均通过 Meg3-siRNA 的治疗而逆转。此外，在该体外模型中，p53 也被定性为 Meg3 的下游靶标。此外，p53 敲低可保护 RBMVEC 免受 OGD + 高血糖再灌注诱导的铁死亡的影响，而 p53 的过度表达则产生相反的作用，这意味着 p53 是铁死亡的正调节因子。此外，p53的过表达或敲低显着调节了暴露于OGD联合高血糖治疗引起的损伤的RBMVEC中GPX4的表达。此外，将p53重新引入被Meg3沉默的细胞后，GPX4表达再次受到抑制。最后，染色质免疫沉淀测定发现 p53 与 GPX4 启动子结合。总之，这些数据表明，通过调节 GPX4 转录和表达，Meg3-p53 信号通路介导 OGD 联合高血糖再灌注诱导损伤后 RBMVEC 的铁死亡。
Individuals with diabetes are exposed to a higher risk of perioperative stroke than non-diabetics mainly due to persistent hyperglycemia. LncRNA Meg3 has been considered as an important mediator in regulating ischemic stroke. However, the functional and regulatory roles of Meg3 in diabetic brain ischemic injury remain unclear. In this study, rat brain microvascular endothelial cells (RBMVECs) were exposed to 6 h of oxygen and glucose deprivation (OGD), and subsequent reperfusion via incubating cells with glucose of various high concentrations for 24 h to imitate in vitro diabetic brain ischemic injury. It was shown that the marker events of ferroptosis and increased Meg3 expression occurred after the injury induced by OGD combined with hyperglycemia. However, all ferroptotic events were reversed with the treatment of Meg3-siRNA. Moreover, in this in vitro model, p53 was also characterized as a downstream target of Meg3. Furthermore, p53 knockdown protected RBMVECs against OGD + hyperglycemic reperfusion-induced ferroptosis, while the overexpression of p53 exerted opposite effects, implying that p53 served as a positive regulator of ferroptosis. Additionally, the overexpression or knockdown of p53 significantly modulated GPX4 expression in RBMVECs exposed to the injury induced by OGD combined with hyperglycemic treatment. Furthermore, GPX4 expression was suppressed again after the reintroduction of p53 into cells silenced by Meg3. Finally, chromatin immunoprecipitation assay uncovered that p53 was bound to GPX4 promoter. Altogether, these data revealed that, by modulating GPX4 transcription and expression, the Meg3-p53 signaling pathway mediated the ferroptosis of RBMVECs upon injury induced by OGD combined with hyperglycemic reperfusion.