Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States of America.
Center for Translational Research on Inflammatory Diseases, Michael E. DeBakey Veterans Affairs Medical Center, Houston, Texas, United States of America.
PLoS One. 2020 Oct 13;15(10):e0240164. doi: 10.1371/journal.pone.0240164. eCollection 2020.
Acute inflammation begins with leukocyte P-selectin glycoprotein ligand-1 (PSGL-1) binding to P-selectin on inflamed endothelium and platelets. In pathologic conditions, this process may contribute to secondary organ damage, like sepsis-induced liver injury. Therefore, developing novel therapies to attenuate inflammation may be beneficial. We previously reported that recombinant human vimentin (rhVim) binds P-selectin to block leukocyte adhesion to endothelium and platelets. In this study, we used SPOT-peptide arrays to identify the rod domain as the active region within rhVim that interacts with P-selectin. Indeed, recombinant human rod domain of vimentin (rhRod) binds to P-selectin with high affinity, with in silico modeling suggesting that rhRod binds P-selectin at or near the PSGL-1 binding site. Using bio-layer interferometry, rhRod decreases PSGL-1 binding to immobilized P-selectin, corroborating the in silico data. Under parallel-plate flow, rhRod blocks leukocyte adhesion to fibrin(ogen)-captured platelets, P-selectin/Fc-coated channels, and IL-1β/IL-4-co-stimulated human umbilical vein endothelial cells. Finally, using intravital microscopy in endotoxemic C57Bl/6 mice, rhRod co-localizes with P-selectin in the hepatic sinusoids and decreases neutrophil adhesion to hepatic sinusoids. These data suggest a potential role for rhRod in attenuating inflammation through directly blocking P-selectin-PSGL-1 interactions.
急性炎症始于白细胞 P 选择素糖蛋白配体-1（PSGL-1）与炎症内皮细胞和血小板上的 P 选择素结合。在病理条件下，这个过程可能导致继发性器官损伤，如脓毒症引起的肝损伤。因此，开发新型治疗方法来减轻炎症可能是有益的。我们之前报道过重组人波形蛋白（rhVim）与 P 选择素结合以阻止白细胞与内皮细胞和血小板的黏附。在这项研究中，我们使用 SPOT 肽阵列鉴定出 rod 结构域是 rhVim 中与 P 选择素相互作用的活性区域。事实上，重组人波形蛋白的 rod 结构域（rhRod）与 P 选择素有很高的亲和力结合，计算建模表明 rhRod 在 PSGL-1 结合位点或其附近与 P 选择素结合。使用生物层干涉测量法，rhRod 降低了 PSGL-1 与固定化 P 选择素的结合，这与计算数据相符。在平行板流动条件下，rhRod 阻止白细胞黏附在纤维蛋白（原）捕获的血小板、P 选择素/Fc 包被的通道和 IL-1β/IL-4 共刺激的人脐静脉内皮细胞上。最后，在内毒素血症 C57Bl/6 小鼠的活体显微镜下，rhRod 与 P 选择素在肝窦共定位，并减少中性粒细胞与肝窦的黏附。这些数据表明，rhRod 通过直接阻断 P 选择素-PSGL-1 相互作用，在减轻炎症中可能具有潜在作用。
