Endo-PDI is required for TNFα-induced angiogenesis
Endo-PDI is required for TNFα-induced angiogenesis
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DOI：
10.1016/j.freeradbiomed.2013.09.028
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发表时间：
2013-12-01
影响因子：
7.4
通讯作者：
Brandes, Ralf P.
中科院分区：
文献类型：
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作者：
Camargo, Livia de Lucca;Babelova, Andrea;Brandes, Ralf P.
蛋白质二硫键异构酶（PDI）及其同系物是促进ER中蛋白质折叠的氧化还原酶。Endo-PDI（也称为ERp 46）在内皮细胞中高度表达。它属于PDI家族，但其生理功能在很大程度上是未知的。我们研究了Endo-PDI在内皮血管生成反应中的作用。刺激人脐静脉内皮细胞（用TNF α（10 ng/ml））增加ERK 1/ 2磷酸化。这种作用在很大程度上减弱了Endo-PDI siRNA，而JNK和p38 MAP激酶磷酸化是Endo-PDI独立的。类似地，TNF α刺激的NF-κ B信号传导（由1 κ B α降解确定）以及TNF α诱导的ICAM表达不受Endo-PDI siRNA的影响。如非渗透性抑制剂和PDI中和抗体所证明的，Endo-PDI的作用不是由细胞外巯基交换或细胞表面PDI介导的。此外，外源性添加的PDI不能在Endo-PDI敲低后恢复ERK 1/2活化。这表明Endo-PDI可能通过维持Ras/Raf/MEK/ERK途径在细胞内起作用。“果然，果然。通过G-LISA和Raf磷酸化测量的减弱的Ras活化。ERR激活通过转录因子AP-1影响基因表达，AP-1控制MMP-9和组织蛋白酶B，这两种蛋白酶是血管生成所需的。TNF α刺激的MMP-9和组织蛋白酶B诱导通过沉默Endo-PDI而减少。因此，在球体生长测定中，组织蛋白酶B或Endo-PDI siRNA的抑制阻断了TNF α刺激的血管生成反应。此外，响应于TNF α的离体管形成和体内基质胶血管生成通过Endo-PDI siRNA减弱。总之，我们的研究确立了Endo-PDI作为AP-1驱动的基因表达和内皮血管生成功能的一种新的重要介质。(C)2013 Elsevier Inc. All rights reserved.
Protein disulfide isomerase (PDI) and its homologs are oxidoreductases facilitating protein folding in the ER. Endo-PDI (also termed ERp46) is highly expressed in endothelial cells. It belongs to the PDI family but its physiological function is largely unknown. We studied the role of Endo-PDI in endothelial angiogenic responses. Stimulation of human umbilical vein endothelial cells (with TNF alpha (10 ng/ml) increased ERK1/ 2 phosphorylation. This effect was largely attenuated by Endo-PDI siRNA, whereas JNK and p38 MAP kinase phosphorylation was Endo-PDI independent. Similarly, TNF alpha-stimulated NF-kappa B signaling determined by 1 kappa B alpha degradation as well as TNF alpha-induced ICAM expression was unaffected by Endo-PDI siRNA. The action of Endo-PDI was not mediated by extracellular thiol exchange or cell surface PDI as demonstrated by nonpermeative inhibitors and PDI-neutralizing antibody. Moreover, exogenously added PDI failed to restore ERK1/2 activation after Endo-PDI knockdown. This suggests that Endo-PDI acts intracellularly potentially by maintaining the Ras/Raf/MEK/ERK pathway. Indeed, knockdown of Endo-PDI! attenuated Ras activation measured by G-LISA and Raf phosphorylation. ERR activation influences gene expression by the transcriptional factor AP-1, which controls MMP-9 and cathepsin B, two proteases required for angiogenesis. TNFa-stimulated MMP-9 and cathepsin B induction was reduced by silencing of Endo-PDI. Accordingly, inhibition of cathepsin B or Endo-PDI siRNA blocked the TNFa-stimulated angiogenic response in the spheroid outgrowth assays. Moreover ex vivo tube formation and in vivo Matrigel angiogenesis in response to TNFa were attenuated by Endo-PDI siRNA. In conclusion, our study establishes Endo-PDI as a novel, important mediator of AP-1-driven gene expression and endothelial angiogenic function. (C) 2013 Elsevier Inc. All rights reserved.