The miR-322-TRAF3 Circuit Mediates the Pro-apoptotic Effect of High Glucose on Neural Stem Cells
The miR-322-TRAF3 Circuit Mediates the Pro-apoptotic Effect of High Glucose on Neural Stem Cells
复制标题
DOI：
10.1093/toxsci/kfu271
复制
发表时间：
2015-03-01
影响因子：
3.8
通讯作者：
Yang, Peixin
中科院分区：
文献类型：
--
作者：
Gu, Hui;Yu, Jingwen;Yang, Peixin
母亲糖尿病会增加神经管缺陷 (NTD) 的风险，并且半胱天冬酶依赖性细胞凋亡和基因失调与该疾病过程有关。本研究探讨了 miR-322 及其假定靶基因 TNF 受体相关因子 3 (TRAF3) 在高糖诱导的细胞凋亡中的作用。在非糖尿病和糖尿病母鼠的胚胎中以及高葡萄糖条件下的神经干细胞中评估了 miR-322 和 TRAF3 的表达。母亲体内糖尿病和体外高血糖显着下调 miR-322 并上调 TRAF3 蛋白表达。抗氧化酶超氧化物歧化酶 1 (SOD1) 的过度表达或 SOD1 模拟物 Tempol 的治疗分别消除了母体糖尿病或高血糖对 miR-322 和 TRAF3 表达的影响。 miRNA 目标预测算法揭示了 TRAF3 mRNA 30 个非翻译区 (UTR) 的 2 个 miR-322 结合位点。使用生物素标记的 miR-322 进行的 RNA Pull-down 测定表明，miR-322 在一个特定结合位点与 TRAF3 mRNA 的 3'-UTR 相互作用。 miR-322模拟物或TRAF3敲低可阻断高葡萄糖增加的TRAF3蛋白表达和细胞凋亡，而miR-322抑制剂模拟高葡萄糖导致TRAF3上调和细胞凋亡的作用。这项研究表明，母亲糖尿病和高血糖都会通过氧化应激负向调节 miR-322。 miR-322 与 TRAF3 的 3'-UTR 相互作用并抑制其翻译。 miR-322-TRAF3 通路与高葡萄糖诱导的 caspase 激活和细胞凋亡有关。
Maternal diabetes increases the risk of neural tube defects (NTDs), and caspase-dependent apoptosis and gene dysregulation are implicated in this disease process. This study investigates the role of miR-322 and its putative target gene, TNF receptor-associated factor 3 (TRAF3), in high glucose-induced apoptosis. miR-322 and TRAF3 expression were assessed in embryos of nondiabetic and diabetic dams, and in neural stem cells under high glucose conditions. Maternal diabetes in vivo and high glucose in vitro significantly down-regulated miR-322 and up-regulated TRAF3 protein expression. Overexpression of the antioxidant enzyme, superoxide dismutase 1 (SOD1), or treatment with the SOD1 mimetic Tempol, abolished the effect of maternal diabetes or high glucose on miR-322 and TRAF3 expression, respectively. A miRNA target prediction algorithm reveals 2 miR-322 binding sites the 30-untranslated region (UTR) of TRAF3 mRNA. A RNA pull-down assay using biotin-labeled miR-322 revealed that miR-322 interacted with the 3'-UTR of TRAF3 mRNA at one specific binding site. The miR-322 mimic or TRAF3 knockdown blocked high glucose-increased TRAF3 protein expression and apoptosis, whereas the miR-322 inhibitor mimicked the effect of high glucose leading to TRAF3 up-regulation and apoptosis. This study demonstrates that both maternal diabetes and high glucose negatively regulate miR-322 through oxidative stress. miR-322 interacts with the 3'-UTR of TRAF3 and represses its translation. The miR-322-TRAF3 pathway is implicated in high glucose-induced caspase activation and apoptosis.