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Endothelial glycocalyx; Glomerular endothelial cell; Minimal change disease Glicocàlix endotelial; Cèl·lula endotelial glomerular; Malaltia de canvis mínims Glicocálix endotelial; Célula endotelial glomerular; Enfermedad de cambios mínimos Introduction 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. Methods 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 (n = 11 MCD, n = 5 controls). In vitro, we cultured immortalized human GEnC with sera from control subjects and patients with MCD/SSNS sera in relapse (n = 5 per group) and performed Western blotting of thrombomodulin of cell lysates as surrogate marker of endothelial activation. Results 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. Conclusion 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.

Disfunció endotelial; Envellliment cel·lular Disfunción endotelial; Envejecimiento celular Endothelial dysfunction; Senescence Endothelial cell dysfunction is the principal cause of several cardiovascular diseases that are increasing in prevalence, healthcare costs, and mortality. Developing a standardized, representative in vitro model of endothelial cell dysfunction is fundamental to a greater understanding of the pathophysiology, and to aiding the development of novel pharmacological therapies. We subjected human umbilical vein endothelial cells (HUVECs) to different periods of nutrient deprivation or increasing doses of H2O2 to represent starvation or elevated oxidative stress, respectively, to investigate changes in cellular function. Both in vitro cellular models of endothelial cell dysfunction-associated senescence developed in this study, starvation and oxidative stress, were validated by markers of cellular senescence (increase in β-galactosidase activity, and changes in senescence gene markers SIRT1 and P21) and endothelial dysfunction as denoted by reductions in angiogenic and migratory capabilities. HUVECs showed a significant H2O2 concentration-dependent reduction in cell viability (p < 0.0001), and a significant increase in oxidative stress (p < 0.0001). Furthermore, HUVECs subjected to 96 h of starvation, or exposed to concentrations of H2O2 of 400 to 1000 μM resulted in impaired angiogenic and migratory potentials. These models will enable improved physiological studies of endothelial cell dysfunction, and the rapid testing of cellular efficacy and toxicity of future novel therapeutic compounds. This research was funded by Beca de Investigacion Basica en Cardiologia from the Sociedad Española de Cardiologia, Fondo de Investigacion en Salud (grants PI18/00277, PI16/00742, PI19/00264, PI18/00960 and PI15/00553) from the Spanish Ministry of Science and Innovation, Instituto de Salud Carlos III–Fondo Europeo de Desarrollo Regional (FEDER), and Spanish Society of Respiratory Medicine (SEPAR) and Catalan Society of Pneumology (SOCAP) grants. FRJT and OTC are the recipients of the Ayudas para la formación de profesorado universitario (FPU19/04925) and Miguel Servet (CP17/00114) grants, respectively, from the Spanish Ministry of Science and Innovation. IDIBAPS belongs to the CERCA Programme, and receives partial funding from the Generalitat de Catalunya. Cofunding was provided by the Fondo Europeo de Desarrollo Regional (FEDER); “Una manera de hacer Europa”.

Biomarcadores; Disfunción endotelial; Células progenitoras Biomarcadors; Disfunció endotelial; Cèl·lules progenitores Biomarkers; Endothelial dysfunction; Progenitor cells Background: Endothelial dysfunction is central to PAH. In this study, we simultaneously analysed circulating levels of endothelial microvesicles (EMVs) and progenitor cells (PCs) in PAH and in controls, as biomarkers of pulmonary endothelial integrity and evaluated differences among PAH subtypes and as a response to treatment. Methods: Forty-seven controls and 144 patients with PAH (52 idiopathic, 9 heritable, 31 associated with systemic sclerosis, 15 associated with other connective tissue diseases, 20 associated with HIV and 17 associated with portal hypertension) were evaluated. Forty-four patients with scleroderma and 22 with HIV infection, but without PAH, were also studied. Circulating levels of EMVs, total (CD31+CD42b−) and activated (CD31+CD42b−CD62E+), as well as circulating PCs (CD34+CD133+CD45low) were measured by flow cytometry and the EMVs/PCs ratio was computed. In treatment-naïve patients, measurements were repeated after 3 months of PAH therapy. Results: Patients with PAH showed higher numbers of EMVs and a lower percentage of PCs, compared with healthy controls. The EMV/PC ratio was increased in PAH patients, and in patients with SSc or HIV without PAH. After starting PAH therapy, individual changes in EMVs and PCs were variable, without significant differences being observed as a group. Conclusion: PAH patients present disturbed vascular homeostasis, reflected in changes in circulating EMV and PC levels, which are not restored with PAH targeted therapy. Combined measurement of circulating EMVs and PCs could be foreseen as a potential biomarker of endothelial dysfunction in PAH. This research was funded by grants PI12/00510, PI15/00582 and PI18/00960 from the Institute of Health Carlos III (ISCiii), Spain, co-funded by the European Union (ERDF/ESF); the Catalan Society of Respiratory Medicine (SOCAP); and the Fundación Contra la Hipertensión Pulmonar (FCHP). OTC is the former recipient of a Marie Curie Post-Doctoral Fellowship Award BIOTRACK-IDIBAPS, and the current recipient of a Miguel Servet contract from ISCiii (CP17/00114).