TY - JOUR
T1 - Circulating Permeability Factors in Focal Segmental Glomerulosclerosis
T2 - In Vitro Detection
AU - Veissi, Susan T.
AU - Smeets, Bart
AU - van Wijk, Joanna A. E.
AU - Classens, René
AU - van der Velden, Thea J. A. M.
AU - Jeronimus-Klaasen, Annelies
AU - Veltkamp, Floor
AU - Mak – Nienhuis, E. M.
AU - Morello, William
AU - Montini, Giovanni
AU - Bouts, Antonia H. M.
AU - van den Heuvel, Lambertus P. W. J.
AU - Schreuder, Michiel F.
N1 - Funding Information: This study was performed on behalf of the LEARNS (LEvamisole Adjuvant therapy to reduce relapses of nephrotic syndrome) Consortium, an interuniversity collaboration in the Netherlands, funded by the Dutch Kidney Foundation (CP 16.03). Publisher Copyright: © 2022 International Society of Nephrology
PY - 2022/12
Y1 - 2022/12
N2 - Introduction: The recurrence of proteinuria after kidney transplantation in patients with focal segmental glomerulosclerosis (FSGS) is considered proof of the presence of circulating permeability factors (CPFs). The aim of this study is to demonstrate the presence of plasma CPFs using series of in vitro assays. Methods: Podocytes and endothelial cells (glomerular microvascular endothelial cells [GMVECs]) were incubated with plasma from FSGS patients with presumed CPFs in relapse and remission and from steroid-resistant nephrotic syndrome (SRNS), steroid-sensitive nephrotic syndrome (SSNS), membranous nephropathy (MN), and healthy controls (hCtrls). Cell viability, podocyte actin cytoskeleton architecture, and reactive oxygen species (ROS) formation with or without ROS scavenger were investigated by Cell Counting Kit-8 assay, immunofluorescence staining, and CM-H2DCFDA probing, respectively. Results: Presumed CPF-containing plasma causes a series of events in podocytes but not in GMVECs. These events include actin cytoskeleton rearrangement and excessive formation of ROS, which results in podocyte loss. These effects were solely observed in response to CPF plasma collected during relapse, but not in response to plasma of hCtrls, or patients with SRNS, SSNS, and MN. The copresence of dimethylthiourea, a scavenger of ROS, abolished the aforementioned effects of CPF plasma. Conclusion: We provide a panel of in vitro bioassays to measure podocyte injury and predict the presence of CPFs in plasma of patients with nephrotic syndrome (NS), providing a new framework for monitoring CPF activity that may contribute to future NS diagnostics or used for disease monitoring purposes. Moreover, our findings suggest that the inhibition of ROS formation or facilitating rapid ROS scavenging may exert beneficial effects in patients with CPFs.
AB - Introduction: The recurrence of proteinuria after kidney transplantation in patients with focal segmental glomerulosclerosis (FSGS) is considered proof of the presence of circulating permeability factors (CPFs). The aim of this study is to demonstrate the presence of plasma CPFs using series of in vitro assays. Methods: Podocytes and endothelial cells (glomerular microvascular endothelial cells [GMVECs]) were incubated with plasma from FSGS patients with presumed CPFs in relapse and remission and from steroid-resistant nephrotic syndrome (SRNS), steroid-sensitive nephrotic syndrome (SSNS), membranous nephropathy (MN), and healthy controls (hCtrls). Cell viability, podocyte actin cytoskeleton architecture, and reactive oxygen species (ROS) formation with or without ROS scavenger were investigated by Cell Counting Kit-8 assay, immunofluorescence staining, and CM-H2DCFDA probing, respectively. Results: Presumed CPF-containing plasma causes a series of events in podocytes but not in GMVECs. These events include actin cytoskeleton rearrangement and excessive formation of ROS, which results in podocyte loss. These effects were solely observed in response to CPF plasma collected during relapse, but not in response to plasma of hCtrls, or patients with SRNS, SSNS, and MN. The copresence of dimethylthiourea, a scavenger of ROS, abolished the aforementioned effects of CPF plasma. Conclusion: We provide a panel of in vitro bioassays to measure podocyte injury and predict the presence of CPFs in plasma of patients with nephrotic syndrome (NS), providing a new framework for monitoring CPF activity that may contribute to future NS diagnostics or used for disease monitoring purposes. Moreover, our findings suggest that the inhibition of ROS formation or facilitating rapid ROS scavenging may exert beneficial effects in patients with CPFs.
KW - actin cytoskeleton damage
KW - circulating permeability factor
KW - focal segmental glomerulosclerosis
KW - nephrotic syndrome
KW - podocytes
KW - reactive oxygen species
UR - http://www.scopus.com/inward/record.url?scp=85139663678&partnerID=8YFLogxK
U2 - https://doi.org/10.1016/j.ekir.2022.09.014
DO - https://doi.org/10.1016/j.ekir.2022.09.014
M3 - Article
C2 - 36506233
SN - 2468-0249
VL - 7
SP - 2691
EP - 2703
JO - Kidney International Reports
JF - Kidney International Reports
IS - 12
ER -