Institute for Environmental Medicine, Department of Pharmacology, University of Pennsylvania School of Medicine, 1 John Morgan Bldg., 3620 Hamilton Walk, Philadelphia, PA 19104-6068, USA.
FASEB J. 2011 Jan;25(1):348-57. doi: 10.1096/fj.10-169789. Epub 2010 Sep 27.
Elevated generation of reactive oxygen species (ROS) by endothelial enzymes, including NADPH-oxidase, is implicated in vascular oxidative stress and endothelial proinflammatory activation involving exposure of vascular cell adhesion molecule-1 (VCAM-1). Catalase and superoxide dismutase (SOD) conjugated with antibodies to platelet/endothelial cell adhesion molecule 1 (PECAM-1) bind specifically to endothelium and inhibit effects of corresponding ROS, H(2)O(2), and superoxide anion. In this study, anti-PECAM/SOD, but not anti-PECAM/catalase or nontargeted enzymes, including polyethylene glycol (PEG)-SOD, inhibited 2- to 3-fold VCAM expression caused by tumor necrosis factor (TNF), interleukin-1β, and lipopolysaccharide. Anti- PECAM/SOD, but not nontargeted counterparts, accumulated in vascular endothelium after intravenous injection, localized in endothelial endosomes, and inhibited by 70% lipopolysaccharide-caused VCAM-1 expression in mice. Anti-PECAM/SOD colocalized with EEA-1-positive endothelial vesicles and quenched ROS produced in response to TNF. Inhibitors of NADPH oxidase and anion channel ClC3 blocked TNF-induced VCAM expression, affirming that superoxide produced and transported by these proteins, respectively, mediates inflammatory signaling. Anti-PECAM/SOD abolished VCAM expression caused by poly(I:C)-induced activation of toll-like receptor 3 localized in intracellular vesicles. These results directly implicate endosomal influx of superoxide in endothelial inflammatory response and suggest that site-specific interception of this signal attained by targeted delivery of anti-PECAM/SOD into endothelial endosomes may have anti-inflammatory effects.
内皮酶（包括 NADPH 氧化酶）产生的活性氧（ROS）增加与血管氧化应激和内皮前炎性激活有关，涉及血管细胞黏附分子-1（VCAM-1）的暴露。与血小板/内皮细胞黏附分子 1（PECAM-1）抗体偶联的过氧化氢酶和超氧化物歧化酶（SOD）特异性结合到内皮细胞并抑制相应的 ROS、H₂O₂和超氧阴离子的作用。在这项研究中，抗 PECAM/SOD，但不是抗 PECAM/过氧化氢酶或非靶向酶（包括聚乙二醇（PEG）-SOD），抑制了肿瘤坏死因子（TNF）、白细胞介素-1β和脂多糖引起的 VCAM 表达增加 2-3 倍。抗 PECAM/SOD，但不是非靶向酶，在静脉注射后在内皮细胞中积累，定位于内皮内体，并抑制脂多糖引起的 70%的 VCAM-1 表达。抗 PECAM/SOD 与 EEA-1 阳性内皮小泡共定位，并抑制 TNF 引起的 ROS 产生。NADPH 氧化酶和阴离子通道 ClC3 的抑制剂阻断了 TNF 诱导的 VCAM 表达，证实了分别由这些蛋白产生和转运的超氧阴离子介导了炎症信号。抗 PECAM/SOD 消除了聚（I:C）诱导的 TLR3 在内体中的激活引起的 VCAM 表达。这些结果直接表明，内体中超氧阴离子的流入参与了内皮炎症反应，并表明通过将抗 PECAM/SOD 靶向递送至内皮内体来特异性阻断该信号可能具有抗炎作用。
