Soni Dheeraj, Wang Dong-Mei, Regmi Sushil C, Mittal Manish, Vogel Stephen M, Schlüter Dirk, Tiruppathi Chinnaswamy
1Department of Pharmacology and Center for Lung and Vascular Biology, College of Medicine, University of Illinois, Chicago, IL USA.
2Institute of Medical Microbiology and Hospital Hygiene, Otto-von-Guericke University Magdeburg, Magdeburg, Germany.
Cell Death Discov. 2018 May 16;4:60. doi: 10.1038/s41420-018-0056-3. eCollection 2018.
Vascular endothelial cadherin (VE-cad) expression at endothelial adherens junctions (AJs) regulates vascular homeostasis. Here we show that endothelial A20 is required for VE-cad expression at AJs to maintain and repair the injured endothelial barrier. In endothelial cell (EC)-restricted (A20) knockout ( ) mice, LPS challenge caused uncontrolled lung vascular leak and persistent sequestration of polymorphonuclear neutrophil (PMNs). Importantly, mice exhibited drastically reduced VE-cad expression in lungs compared with wild-type counterparts. Endothelial expression of wild-type A20 but not the deubiquitinase-inactive A20 mutant (A20) prevented VE-cad ubiquitination, restored VE-cad expression, and suppressed lung vascular leak in mice. Interestingly, IRAK-M-mediated nuclear factor-κB (NF-κB) signaling downstream of TLR4 was required for A20 expression in ECs. interleukin-1 receptor-associated kinase M (IRAK-M) knockdown suppressed basal and LPS-induced A20 expression in ECs. Further, in vivo silencing of IRAK-M in mouse lung vascular ECs through the CRISPR-Cas9 system prevented expression of A20 and VE-cad while augmenting lung vascular leak. These results suggest that targeting of endothelial A20 is a potential therapeutic strategy to restore endothelial barrier integrity in the setting of acute lung injury.
血管内皮钙黏蛋白（VE-cad）在内皮黏附连接（AJs）处的表达调节血管稳态。在此我们表明，内皮细胞中的A20是AJs处VE-cad表达所必需的，以维持和修复受损的内皮屏障。在内皮细胞（EC）特异性（A20）基因敲除（ ）小鼠中，脂多糖（LPS）刺激导致肺血管渗漏失控以及多形核中性粒细胞（PMN）持续滞留。重要的是，与野生型小鼠相比， 小鼠肺中VE-cad表达显著降低。野生型A20而非去泛素化酶失活的A20突变体（A20）的内皮表达可防止VE-cad泛素化，恢复VE-cad表达，并抑制 小鼠的肺血管渗漏。有趣的是，Toll样受体4（TLR4）下游由白细胞介素-1受体相关激酶M（IRAK-M）介导的核因子-κB（NF-κB）信号传导是ECs中A20表达所必需的。敲低IRAK-M可抑制ECs中基础的和LPS诱导的A20表达。此外，通过CRISPR-Cas9系统在小鼠肺血管ECs中体内沉默IRAK-M可阻止A20和VE-cad的表达，同时增加肺血管渗漏。这些结果表明，靶向内皮A20是在急性肺损伤情况下恢复内皮屏障完整性的一种潜在治疗策略。
