PuSH - Publikationsserver des Helmholtz Zentrums München

Artunc, F. ; Bohnert, B.N. ; Schneider, J.C.* ; Staudner, T.* ; Sure, F.* ; Ilyaskin, A.V.* ; Wörn, M.* ; Essigke, D. ; Janessa, A.* ; Nielsen, N.V.* ; Birkenfeld, A.L. ; Etscheid, M.* ; Haerteis, S.* ; Korbmacher, C.* ; Kanse, S.M.*

Proteolytic activation of the epithelial sodium channel (ENaC) by factor VII activating protease (FSAP) and its relevance for sodium retention in nephrotic mice.

Pflugers Arch. 474, 217-229 (2022)
Verlagsversion DOI PMC
Open Access Gold (Paid Option)
Creative Commons Lizenzvertrag
Proteolytic activation of the epithelial sodium channel (ENaC) by aberrantly filtered serine proteases is thought to contribute to renal sodium retention in nephrotic syndrome. However, the identity of the responsible proteases remains elusive. This study evaluated factor VII activating protease (FSAP) as a candidate in this context. We analyzed FSAP in the urine of patients with nephrotic syndrome and nephrotic mice and investigated its ability to activate human ENaC expressed in Xenopus laevis oocytes. Moreover, we studied sodium retention in FSAP-deficient mice (Habp2-/-) with experimental nephrotic syndrome induced by doxorubicin. In urine samples from nephrotic humans, high concentrations of FSAP were detected both as zymogen and in its active state. Recombinant serine protease domain of FSAP stimulated ENaC-mediated whole-cell currents in a time- and concentration-dependent manner. Mutating the putative prostasin cleavage site in γ-ENaC (γRKRK178AAAA) prevented channel stimulation by the serine protease domain of FSAP. In a mouse model for nephrotic syndrome, active FSAP was present in nephrotic urine of Habp2+/+ but not of Habp2-/- mice. However, Habp2-/- mice were not protected from sodium retention compared to nephrotic Habp2+/+ mice. Western blot analysis revealed that in nephrotic Habp2-/- mice, proteolytic cleavage of α- and γ-ENaC was similar to that in nephrotic Habp2+/+ animals. In conclusion, active FSAP is excreted in the urine of nephrotic patients and mice and activates ENaC in vitro involving the putative prostasin cleavage site of γ-ENaC. However, endogenous FSAP is not essential for sodium retention in nephrotic mice.
Altmetric
Weitere Metriken?
[➜Einloggen]
Zusatzinfos bearbeiten [➜Einloggen]
Publikationstyp Artikel: Journalartikel
Dokumenttyp Wissenschaftlicher Artikel
Korrespondenzautor
Schlagwörter Epithelial Sodium Channel (enac) ; Fsap-habp2 ; Factor Vii Activating Protease ; Nephrotic Syndrome ; Serine Protease; Gamma-subunit; Cleavage; Receptors; Peptide; Plasmin; Mouse
ISSN (print) / ISBN 0031-6768
e-ISSN 1432-2013
Zeitschrift Pflügers Archiv
Quellenangaben Band: 474, Heft: 2, Seiten: 217-229 Artikelnummer: , Supplement: ,
Verlag Springer
Verlagsort Tiergartenstrasse 17, D-69121 Heidelberg, Germany
Nichtpatentliteratur Publikationen
Begutachtungsstatus Peer reviewed
Institut(e) Institute of Diabetes Research and Metabolic Diseases (IDM)
Förderungen DFG