Bauer Colin, Piani Federica, Banks Mindy, Ordoñez Flor A, de Lucas-Collantes Carmen, Oshima Kaori, Schmidt Eric P, Zakharevich Igor, Segarra Alfons, Martinez Cristina, Roncal-Jimenez Carlos, Satchell Simon C, Bjornstad Petter, Lucia Marshall Scott, Blaine Judith, Thurman Joshua M, Johnson Richard J, Cara-Fuentes Gabriel
Section of Pediatric Nephrology, Department of Pediatrics, Children's Hospital Colorado, Aurora, Colorado, USA.
Department of Medicine and Surgery Sciences, Alma Mater Studiorum University of Bologna, Bologna, Italy.
Kidney Int Rep. 2021 Dec 16;7(4):797-809. doi: 10.1016/j.ekir.2021.11.037. eCollection 2022 Apr.
Minimal change disease (MCD) is considered a podocyte disorder triggered by unknown circulating factors. Here, we hypothesized that the endothelial cell (EC) is also involved in MCD.
We studied 45 children with idiopathic nephrotic syndrome (44 had steroid sensitive nephrotic syndrome [SSNS], and 12 had biopsy-proven MCD), 21 adults with MCD, and 38 healthy controls (30 children, 8 adults). In circulation, we measured products of endothelial glycocalyx (EG) degradation (syndecan-1, heparan sulfate [HS] fragments), HS proteoglycan cleaving enzymes (matrix metalloprotease-2 [MMP-2], heparanase activity), and markers of endothelial activation (von Willebrand factor [vWF], thrombomodulin) by enzyme-linked immunosorbent assay (ELISA) and mass spectrometry. In human kidney tissue, we assessed glomerular EC (GEnC) activation by immunofluorescence of caveolin-1 ( 11 MCD, 5 controls). , we cultured immortalized human GEnC with sera from control subjects and patients with MCD/SSNS sera in relapse ( 5 per group) and performed Western blotting of thrombomodulin of cell lysates as surrogate marker of endothelial activation.
In circulation, median concentrations of all endothelial markers were higher in patients with active disease compared with controls and remained high in some patients during remission. In the MCD glomerulus, caveolin-1 expression was higher, in an endothelial-specific pattern, compared with controls. In cultured human GEnC, sera from children with MCD/SSNS in relapse increased thrombomodulin expression compared with control sera.
Our data show that alterations involving the systemic and glomerular endothelium are nearly universal in patients with MCD and SSNS, and that GEnC can be directly activated by circulating factors present in the MCD/SSNS sera during relapse.
微小病变病（MCD）被认为是一种由未知循环因子引发的足细胞疾病。在此，我们推测内皮细胞（EC）也参与了MCD。
我们研究了45例特发性肾病综合征患儿（44例为激素敏感型肾病综合征[SSNS]，12例经活检证实为MCD）、21例成人MCD患者以及38名健康对照者（30名儿童，8名成人）。在循环系统中，我们通过酶联免疫吸附测定（ELISA）和质谱法测量内皮糖萼（EG）降解产物（syndecan-1、硫酸乙酰肝素[HS]片段）、HS蛋白聚糖裂解酶（基质金属蛋白酶-2 [MMP-2]、乙酰肝素酶活性）以及内皮激活标志物（血管性血友病因子[vWF]、血栓调节蛋白）。在人肾组织中，我们通过小窝蛋白-1免疫荧光法评估肾小球EC（GEnC）激活情况（11例MCD，5例对照）。此外，我们用对照受试者血清以及复发期MCD/SSNS患者血清培养永生化人GEnC（每组5例），并对细胞裂解物中的血栓调节蛋白进行蛋白质印迹分析，以此作为内皮激活的替代标志物。
在循环系统中，与对照组相比，活动性疾病患者的所有内皮标志物中位浓度更高，且在部分患者缓解期仍保持较高水平。在MCD肾小球中，与对照组相比，小窝蛋白-1表达更高，呈内皮细胞特异性模式。在培养的人GEnC中，复发期MCD/SSNS患儿的血清与对照血清相比，血栓调节蛋白表达增加。
我们的数据表明，MCD和SSNS患者几乎普遍存在涉及全身和肾小球内皮的改变，并且复发期MCD/SSNS血清中存在的循环因子可直接激活GEnC。
