Targets of tyrosine nitration in diabetic rat retina (Retracted Article)
Targets of tyrosine nitration in diabetic rat retina (Retracted Article)
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DOI：
10.1074/mcp.m700417-mcp200
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发表时间：
2008-05-01
影响因子：
7
通讯作者：
Crabb, John W.
中科院分区：
文献类型：
--
作者：
Zhan, Xianquan;Du, Yunpeng;Crabb, John W.
糖尿病视网膜病变，一种视网膜血管疾病，在用氨基胍（一种诱导型一氧化氮合酶抑制剂）治疗的动物中得到抑制。这种治疗也减少视网膜蛋白质硝化，这是更大的糖尿病大鼠视网膜比非糖尿病视网膜。作为了解糖尿病视网膜病变的分子机制的一种方法，我们寻求从链脲佐菌素诱导的糖尿病大鼠和在高葡萄糖（25 mm）中生长的大鼠视网膜Muller细胞系视网膜中含硝基酪氨酸的蛋白质的身份。通过LC-MS/MS分析了大鼠视网膜和Muller细胞的抗硝基酪氨酸免疫沉淀产物。确定了糖尿病大鼠视网膜中的10种硝化蛋白和在高糖条件下生长的Muller细胞中的3种硝化蛋白;从糖尿病视网膜中初步确定了另外3种含硝基酪氨酸的蛋白。所鉴定的含硝基酪氨酸的蛋白质参与多种过程，包括葡萄糖代谢、信号转导和转录/翻译。硝化蛋白质包括胰岛素响应性葡萄糖转运蛋白4型（GLUT-4），其先前与糖尿病的发病机制有关;外囊复合物组分Exo 70，其在含GLUT-4的囊泡的胰岛素刺激的葡萄糖摄取中起作用;以及成纤维细胞生长因子受体2，其通过成纤维细胞生长因子信号传导影响视网膜血管化。在五种蛋白质中鉴定了酪氨酸磷酸化位点的硝化，包括GLUT-4、外囊复合物组分Exo 70、蛋白酪氨酸磷酸酶eta、感觉神经元突触核蛋白和三磷酸肌醇受体3。在糖尿病和非糖尿病动物的GLUT-4和蛋白酪氨酸磷酸酶eta中常见酪氨酸修饰位点的硝化和磷酸化的定量表明，硝化减少了糖尿病视网膜中这些蛋白质中类似于2x的酪氨酸磷酸化。本研究结果提供了新的见解酪氨酸硝化及其在糖尿病视网膜病变的分子机制的潜在作用。
Diabetic retinopathy, a retinal vascular disease, is inhibited in animals treated with aminoguanidine, an inhibitor of inducible nitric-oxide synthase. This treatment also reduces retinal protein nitration, which is greater in diabetic rat retina than nondiabetic retina. As an approach to understanding the molecular mechanisms of diabetic retinopathy, we sought the identity of nitrotyrosine-containing proteins in retina from streptozotocin-induced diabetic rats and in a rat retinal Muller cell line grown in high glucose (25 mm). Anti-nitrotyrosine immunoprecipitation products from rat retina and Muller cells were analyzed by LC-MS/MS. Ten nitrated proteins in diabetic rat retina and three nitrated proteins in Muller cells grown in high glucose were identified; three additional nitrotyrosine-containing proteins were tentatively identified from diabetic retina. The identified nitrotyrosine-containing proteins participate in a variety of processes including glucose metabolism, signal transduction, and transcription/translation. Among the nitrated proteins were insulin-responsive glucose transporter type 4 (GLUT-4), which has been implicated previously in the pathogenesis of diabetes mellitus; exocyst complex component Exo70, which functions in insulin-stimulated glucose uptake of GLUT-4-containing vesicles; and fibroblast growth factor receptor 2, which influences retinal vascularization via fibroblast growth factor signaling. Nitration of tyrosine phosphorylation sites were identified in five proteins, including GLUT-4, exocyst complex component Exo70, protein-tyrosine phosphatase eta, sensory neuron synuclein, and inositol trisphosphate receptor 3. Quantitation of nitration and phosphorylation at common tyrosine modification sites in GLUT-4 and protein-tyrosine phosphatase eta from diabetic and nondiabetic animals suggests that nitration reduced tyrosine phosphorylation similar to 2x in these proteins from diabetic retina. The present results provide new insights regarding tyrosine nitration and its potential role in the molecular mechanisms of diabetic retinopathy.