Blocking Tyr265 nitration of protein phosphatase 2A attenuates nitrosative stress-induced endothelial dysfunction in renal microvessels
Blocking Tyr265 nitration of protein phosphatase 2A attenuates nitrosative stress-induced endothelial dysfunction in renal microvessels
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阻断蛋白磷酸酶 2A 的 Tyr265 硝化可减轻亚硝化应激诱导的肾微血管内皮功能障碍
DOI：
10.1096/fj.201800885rr
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发表时间：
2019-03-01
期刊：
影响因子：
4.8
通讯作者：
Xu, Gang
中科院分区：
文献类型：
--
作者：
Deng, Yuanjun;Cai, Yang;Xu, Gang
蛋白质酪氨酸 (Tyr) 硝化，即硝基（(NO2)-N-中心点）与 Tyr 残基的共价加成，正在成为内皮功能障碍的候选机制。先前的研究表明，Tyr 硝化主要是由亚硝化应激诱导的，该过程的特征是产生活性氮物种，特别是过氧亚硝酸根阴离子 (ONOO-)，它被认为是在超氧自由基 (O-2(中心点-)) 存在下 NO 的次级产物。然而，迄今为止，亚硝化应激诱导的酪氨酸硝化对内皮功能障碍的影响尚未得到彻底阐明。我们开发了一种内皮功能障碍模型，这一过程称为内皮间质转化 (EndMT)，并评估了 EndMT 过程中 NO、O-2（中心点-）和蛋白质硝化的产生。结果表明，TGF-1刺激诱导EndMT并增加内皮细胞NO和O-2（中心点-）的产生以及蛋白磷酸酶（PP）2A催化亚基的硝化。质谱分析表明Tyr265是蛋白磷酸酶(PP)2A催化亚基中的硝化位点，这种Tyr硝化增加了PP2A活性并破坏了内皮完整性。为了设计内皮靶向抗 PP2Ac 硝化策略，合成了与细胞穿透肽 HIV-1 TAT 蛋白 (TAT) 缀合的模拟肽、酪氨酸 265 野生型 (Y265WT)。 TAT-265WT预处理显着抑制PP2Ac硝化和PP2A活性，并保持内皮细胞的完整性。此外，在单侧尿道梗阻性肾病模型中，注射TAT-265WT可减弱肾脏硝化形成并引起抗毛细血管稀疏。总而言之，这些结果为 TAT-265WT 作为一种易处理药物来预防肾微血管亚硝化应激诱导的内皮功能障碍提供了临床前概念证明。Deng,Y., Cai, Y., Liu, L., Lin, X., Lu, P.,Guo, Y., Han, M., Xu, G. 阻断蛋白磷酸酶 2A 的 Tyr265 硝化可减弱亚硝化应激诱导的肾微血管内皮功能障碍。
Protein tyrosine (Tyr) nitration, the covalent addition of a nitro group ((NO2)-N-center dot) to Tyr residues, is emerging as a candidate mechanism of endothelial dysfunction. Previous studies have shown that Tyr nitration is primarily induced by nitrosative stress, a process characterized by the production of reactive nitrogen species, especially peroxynitrite anion (ONOO-), which is considered a secondary product of NO in the presence of superoxide radicals (O-2(center dot-)). However, the impact of nitrosative stress-induced Tyr nitration on endothelial dysfunction has not been thoroughly elucidated to date. We developed an endothelial dysfunction model, a process called endothelial-to-mesenchymal transition (EndMT), and evaluated the production of NO, O-2(center dot-), and protein nitration during EndMT. The results showed that TGF-1 stimulation induced EndMT and elevated endothelial NO and O-2(center dot-) production as well as nitration of the catalytic subunit of protein phosphatase (PP)2A. Mass spectrometry analysis showed that Tyr265 was the nitration site in the catalytic subunit of protein phosphatase (PP)2A, and this Tyr nitration increased PP2A activity and disrupted endothelial integrity. To devise an endothelial-targeted anti-PP2Ac nitration strategy, a mimic peptide, tyrosine 265 wild type (Y265WT), conjugated with the cell-penetrating peptide HIV-1 TAT protein (TAT) was synthesized. PP2Ac nitration and PP2A activity were significantly inhibited by pretreatment with TAT-265WT, and the integrity of endothelial cells was maintained. Furthermore, injection of TAT-265WT attenuated renal nitration formation and caused anticapillary rarefaction in a unilateral urethral obstructive nephropathy model. Taken together, these results offer preclinical proof of concept for TAT-265WT as a tractable agent to protect against nitrosative stress-induced endothelial dysfunction in renal microvessels.Deng,Y., Cai, Y., Liu, L., Lin, X., Lu, P., Guo, Y., Han, M., Xu, G. Blocking Tyr265 nitration of protein phosphatase 2A attenuates nitrosative stress-induced endothelial dysfunction in renal microvessels.