Thioredoxin-Interacting Protein Expression Is Required for VEGF-Mediated Angiogenic Signal in Endothelial Cells
Thioredoxin-Interacting Protein Expression Is Required for VEGF-Mediated Angiogenic Signal in Endothelial Cells
复制标题
DOI：
10.1089/ars.2012.4761
复制
发表时间：
2013-12-20
影响因子：
6.6
通讯作者：
El-Remessy, Azza B.
中科院分区：
文献类型：
--
作者：
Abdelsaid, Mohammed A.;Matragoon, Suraporn;El-Remessy, Azza B.
目的：硫氧还蛋白相互作用蛋白 (TXNIP) 通过结合和抑制硫氧还蛋白 (TRX) 促进细胞氧化还原态稳态。越来越多的证据表明细胞氧化还原稳态调节血管内皮生长因子（VEGF）介导的信号传导。本研究旨在探讨 TXNIP 在调节 VEGF 介导的 S-谷胱甘肽化和血管生成信号传导中的氧化还原依赖性作用。使用缺氧诱导的新血管形成模型，将用还原型谷胱甘肽（GSH）前体 N-乙酰半胱氨酸（WT-NAC，500mg/kg）处理的 TXNIP 敲除小鼠（TKO）或野生型（WT）与 WT 进行比较。结果：响应缺氧，TKO 和 WT-NAC 小鼠的视网膜显示修复性血运重建和病理性新生血管显着减少，且 VEGF 表达与 WT 相似。与 WT 小鼠相比，VEGF 未能刺激 TKO 小鼠主动脉环的血管萌发。 TKO 小鼠或 WT+NAC 经历了还原应激，与 WT 相比，TRX 还原酶活性增加两倍，还原 GSH 水平增加四倍。在人微血管内皮 (HME) 细胞中，VEGF 刺激血管内皮生长因子受体 2 (VEGFR2) 与低分子量蛋白酪氨酸磷酸酶 (LMW-PTP) 之间的共沉淀。在 HME 细胞中，沉默 TXNIP 表达会减弱 VEGF 诱导的 GSH 氧化和 LMW-PTP 的 S-谷胱甘肽化。这些效应与 VEGFR2 磷酸化受损有关，最终抑制细胞迁移和管形成。 TXNIP 的过表达恢复了 TKO 内皮细胞中的 VEGFR2 磷酸化和细胞迁移。创新：TXNIP 表达是 VEGF 介导的 VEGFR2 激活和体内外血管生成反应所必需的。 TXNIP 表达通过内皮细胞中 LMW-PTP 的 S-谷胱甘肽化调节 VEGFR-2 磷酸化。结论：我们的结果为调节 TXNIP 表达作为以异常血管生成为特征的疾病的潜在治疗靶点提供了新的机制见解。抗氧化剂。氧化还原信号。 19、2199-2212。
Aims: Thioredoxin-interacting protein (TXNIP) contributes to cellular redox-state homeostasis via binding and inhibiting thioredoxin (TRX). Increasing evidence suggests that cellular redox homeostasis regulates vascular endothelial growth factor (VEGF)-mediated signaling. This study aims to examine the redox-dependant role of TXNIP in regulating VEGF-mediated S-glutathionylation and angiogenic signaling. TXNIP-knockout mice (TKO) or wild-type (WT) treated with the reduced glutathione (GSH)-precursor, N-acetyl cysteine (WT-NAC, 500mg/kg) were compared to WT using hypoxia-induced neovascularization model. Results: In response to hypoxia, retinas from TKO and WT-NAC mice showed significant decreases in reparative revascularization and pathological neovascularization with similar VEGF expression compared with WT. VEGF failed to stimulate vascular sprouting from aortic rings of TKO compared to WT mice. TKO mice or WT+NAC experienced reductive stress as indicated by twofold increase in TRX reductase activity and fourfold increase in reduced-GSH levels compared with WT. In human microvascular endothelial (HME) cells, VEGF stimulated co-precipitation between vascular endothelial growth factor receptor 2 (VEGFR2) with low molecular weight protein tyrosine phosphatase (LMW-PTP). Silencing TXNIP expression blunted VEGF-induced oxidation of GSH and S-glutathionylation of the LMW-PTP in HME cells. These effects were associated with impaired VEGFR2 phosphorylation that culminated in inhibiting cell migration and tube formation. Overexpression of TXNIP restored VEGFR2 phosphorylation and cell migration in TKO-endothelial cells. Innovation: TXNIP expression is required for VEGF-mediated VEGFR2 activation and angiogenic response in vivo and in vitro. TXNIP expression regulates VEGFR-2 phosphorylation via S-glutathionylation of LMW-PTP in endothelial cells. Conclusion: Our results provide novel mechanistic insight into modulating TXNIP expression as a potential therapeutic target in diseases characterized by aberrant angiogenesis. Antioxid. Redox Signal. 19, 2199-2212.