Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China.
Institute of Nephrology, Peking University, Beijing, China.
J Cell Mol Med. 2018 Mar;22(3):1769-1777. doi: 10.1111/jcmm.13458. Epub 2017 Nov 23.
Cumulating evidences suggested an important role of sphingosine-1-phosphate (S1P) and its receptors in regulating endothelial barrier integrity. Our previous study revealed that the circulating S1P levels and renal expression of S1PRs correlated with disease activity and renal damage in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). This study investigated the role of S1P and its receptors in myeloperoxidase (MPO)-ANCA-positive IgG-mediated glomerular endothelial cell (GEnC) activation. The effect of S1P on morphological alteration of GEnCs in the presence of MPO-ANCA-positive IgG was observed. Permeability assay was performed to determine endothelial monolayer activation in quantity. Both membrane-bound and soluble ICAM-1 and VCAM-1 levels were measured. Furthermore, antagonists and/or agonists of various S1PRs were employed to determine the role of different S1PRs. S1P enhanced MPO-ANCA-positive IgG-induced disruption of tight junction and disorganization of cytoskeleton in GEnCs. S1P induced further increase in monolayer permeability of GEnC monolayers in the presence of MPO-ANCA-positive IgG. S1P enhanced MPO-ANCA-positive IgG-induced membrane-bound and soluble ICAM-1/VCAM-1 up-regulation of GEnCs. Soluble ICAM-1 levels in the supernatants of GEnCs stimulated by S1P and MPO-ANCA-positive IgG increased upon pre-incubation of S1PR1 antagonist, while pre-incubation of GEnCs with the S1PR1 agonist down-regulated sICAM-1 level. Blocking S1PR2-4 reduced sICAM-1 levels in the supernatants of GEnCs stimulated by S1P and MPO-ANCA-positive IgG. Pre-incubation with S1PR5 agonist could increase sICAM-1 level in the supernatants of GEnC stimulated by S1P and MPO-ANCA-positive IgG. S1P can enhance MPO-ANCA-positive IgG-mediated GEnC activation through S1PR2-5.
越来越多的证据表明，1-磷酸鞘氨醇（S1P）及其受体在调节内皮细胞屏障完整性方面发挥着重要作用。我们之前的研究表明，循环 S1P 水平和 S1PRs 在抗中性粒细胞胞质抗体（ANCA）相关性血管炎（AAV）患者中的表达与疾病活动度和肾损伤相关。本研究探讨了 S1P 及其受体在髓过氧化物酶（MPO）-ANCA 阳性 IgG 介导的肾小球内皮细胞（GEnC）活化中的作用。观察了 S1P 在 MPO-ANCA 阳性 IgG 存在下对 GEnC 形态改变的影响。进行了通透性测定以确定内皮单层激活的程度。测量了膜结合和可溶性细胞间黏附分子-1（ICAM-1）和血管细胞黏附分子-1（VCAM-1）的水平。此外，还使用了各种 S1PR 拮抗剂和/或激动剂来确定不同 S1PR 的作用。S1P 增强了 MPO-ANCA 阳性 IgG 诱导的 GEnC 紧密连接破坏和细胞骨架重排。S1P 在存在 MPO-ANCA 阳性 IgG 的情况下进一步增加了 GEnC 单层的通透性。S1P 增强了 MPO-ANCA 阳性 IgG 诱导的 GEnC 膜结合和可溶性 ICAM-1/VCAM-1 的上调。S1P 和 MPO-ANCA 阳性 IgG 刺激的 GEnC 上清液中的可溶性 ICAM-1 水平在 S1PR1 拮抗剂预孵育时增加，而 GEnC 预孵育 S1PR1 激动剂时则降低 sICAM-1 水平。阻断 S1PR2-4 可降低 S1P 和 MPO-ANCA 阳性 IgG 刺激的 GEnC 上清液中的 sICAM-1 水平。S1PR5 激动剂预孵育可增加 S1P 和 MPO-ANCA 阳性 IgG 刺激的 GEnC 上清液中的 sICAM-1 水平。S1P 可通过 S1PR2-5 增强 MPO-ANCA 阳性 IgG 介导的 GEnC 活化。
