NF-κB（核因子kappa B）在内皮细胞（EC）炎症中起着关键作用。蛋白质ISGylation受E3 ISG15酶调节；然而，NF-κBp65的ISGylation及其在EC功能中的作用尚未得到研究。在这里，我们研究p65是否被ISGylated以及其ISGylation在内皮细胞功能中的作用。进行了体外ISGylation试验和EC炎症试验。EC特异性转基因小鼠用于急性肺损伤的小鼠模型。我们发现，NF-κBp65在静止EC中被ISGylated，并且这种翻译后修饰是可逆的。EC对TNFα（肿瘤坏死因子α）和内毒素的刺激会减少p65的ISGylation，通过减少其与磷酸酶WIP1的结合来促进其丝氨酸磷酸化。机制上，鉴定了SCF（Skp1-Cul1-F-box）蛋白E3连接酶SCFFBXL19作为一个新的ISG15 E3连接酶，目标是催化p65的ISGylation。FBXL19的耗竭增加了p65的磷酸化和EC炎症，表明p65 ISGylation与磷酸化之间存在负相关。此外，EC特异性hFBXL19过表达的人类转基因小鼠表现出肺炎症和实验性急性肺损伤严重度降低。综上，我们的数据揭示了一种新的p65翻译后修饰，由先前未被认识到的SCFFBXL19作为ISG15 E3连接酶的作用来调节EC炎症。

NF-κB (nuclear factor kappa B) plays a pivotal role in endothelial cell (EC) inflammation. Protein ISGylation is regulated by E3 ISG15 ligases; however, ISGylation of NF-κBp65 and its role in EC functions have not been investigated. Here, we investigate whether p65 is ISGylated and the role of its ISGylation in endothelial functions.In vitro ISGylation assay and EC inflammation were performed. EC-specific transgenic mice were utilized in a murine model of acute lung injury.We find that NF-κBp65 is ISGylated in resting ECs and that the posttranslational modification is reversible. TNFα (tumor necrosis factor alpha) and endotoxin stimulation of EC reduce p65 ISGylation, promoting its serine phosphorylation through reducing its association with a phosphatase WIP1. Mechanistically, an SCF (Skp1-Cul1-F-box) protein E3 ligase SCFFBXL19 is identified as a new ISG15 E3 ligase that targets and catalyzes ISGylation of p65. Depletion of FBXL19 increases p65 phosphorylation and EC inflammation, suggesting a negative correlation between p65 ISGylation and phosphorylation. Moreover, EC-specific hFBXL19 overexpressing humanized transgenic mice exhibit reduced lung inflammation and severity of experimental acute lung injury.Together, our data reveal a new posttranslational modification of p65 catalyzed by a previously unrecognized role of SCFFBXL19 as an ISG15 E3 ligase that modulates EC inflammation.