Identification of O-GIcNAcylation Modification in Diabetic Retinopathy and Crosstalk with Phosphorylation of STAT3 in Retina Vascular Endothelium Cells
Identification of O-GIcNAcylation Modification in Diabetic Retinopathy and Crosstalk with Phosphorylation of STAT3 in Retina Vascular Endothelium Cells
复制标题
糖尿病视网膜病变中 O-GlcNAcNA 酰化修饰的鉴定以及视网膜血管内皮细胞中 STAT3 磷酸化的串扰
DOI：
10.1159/000493444
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发表时间：
2018
影响因子：
--
通讯作者：
Wang Fang
中科院分区：
文献类型：
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作者：
Xu Chong;Liu Guo Dong;Feng Le;Zhang Cong Hui;Wang Fang
背景/目的最近，我们观察到高糖条件下原发性视网膜血管内皮细胞（RVECs）和糖尿病视网膜病变（DR）组织中O-GlcNAc （O-linked-ß-N-acetylglucosamine, O-linked-ß-N-acetylglucosamine, O-GlcNAc）修饰以及转录蛋白3 （STAT3）信号传导和激活因子的表达增加。在本研究中，我们重点研究了o - glcnac酰化和STAT3磷酸化的相关性，以及它们对dr的潜在影响。方法检测了o - glcnac酰化和STAT3在dr病变组织和原发RVECs中的表达。通过免疫沉淀和Western blot分析进一步确定o - glcnac酰化与STAT3的关系。采用流式细胞术和Western blot检测o - glcn酰化对人RVEC细胞凋亡及相关蛋白表达的影响。结果糖尿病大鼠视网膜和原代视网膜内皮细胞中o - glcn酰化和pSTAT3水平在高糖条件下显著升高。体外实验表明Tyr705位点对高糖敏感。虽然o - glcn酰化抑制p727STAT3的表达，但增强的o - glcn酰化可以在相对较高的水平上平衡p705STAT3的表达，从而对应于血管内皮生长因子（VEGF）的变化。免疫沉淀显示STAT3同时被o - glcn酰化和磷酸化修饰。接下来，我们观察到过表达o - glcnac酰化可以缓解与JAK2-Tyr705STAT3-VEGF通路相关的人RVEC凋亡。结论o - glcnac酰化可通过STAT3通路缓解DR中RVECs的凋亡，o - glcnac酰化联合STAT3磷酸化可能为DR及其他糖尿病并发症的发生机制开辟新的思路。
Background/AimsRecently, we observed an increase in O-GlcNAc (O-linked-ß-N-acetylglucosamine) modification, and signal transducer and activator of transcription proteins 3 (STAT3) expression in primary retinal vascular endothelial cells (RVECs) under high glucose conditions and tissues altered by diabetic retinopathy (DR). In this study, we focused on the correlations between O-GlcNAcylation and STAT3 phosphorylation, and their potential effects with regards to DR.MethodsExpression of O-GlcNAcylation and STAT3 were detected in DR-affected tissues and primary RVECs. The relationship between O-GlcNAcylation and STAT3 was further delineated by immunoprecipitation and Western blot analysis. Effects of O-GlcNAcylation on human RVEC apoptosis and involved protein expression were assayed with flow cytometry and Western blot.ResultsGlobal O-GlcNAcylation and pSTAT3 levels were significantly elevated in diabetic rat retina and primary RVECs under high glucose conditions. In vitro assays demonstrated that the Tyr705 site was sensitive to high glucose. While O-GlcNAcylation inhibited p727STAT3 expression, augmented O-GlcNAcylation could balance p705STAT3 expression within relatively high levels corresponding to vascular endothelial growth factor (VEGF) changes. Immunoprecipitation revealed that STAT3 was modified by O-GlcNAcylation and phosphorylation simultaneously. Next, we observed that overexpression of O-GlcNAcylation could relieve human RVEC apoptosis related to the JAK2-Tyr705STAT3-VEGF pathway.ConclusionO-GlcNAcylation could relieve RVECs apoptosis through the STAT3 pathway in DR, and O-GlcNAcylation combined with STAT3 phosphorylation might open up new insights into the mechanisms of DR and other diabetic complications.