PuSH - Publication Server of Helmholtz Zentrum München

Sure, F.* ; Afonso, S.* ; Essigke, D. ; Schmidt, P.* ; Kalo, M.Z.* ; Nesterov, V.* ; Kißler, A.* ; Bertog, M.* ; Rinke, R.* ; Wittmann, S.* ; Broeker, K.A.E.* ; Gramberg, T.* ; Artunc, F. ; Korbmacher, C.* ; Ilyaskin, A.V.*

Transmembrane serine protease 2 and proteolytic activation of the epithelial sodium channel in mouse kidney.

J. Am. Soc. Nephrol., DOI: 10.1681/ASN.0000000521 (2024)
Postprint DOI PMC
Open Access Gold (Paid Option)
BACKGROUND: The renal epithelial sodium channel (ENaC) is essential for sodium balance and blood pressure control. ENaC undergoes complex proteolytic activation by not yet clearly identified tubular proteases. Here, we examined a potential role of transmembrane serine protease 2 (TMPRSS2). METHODS: Murine ENaC and TMPRSS2 were (co-)expressed in Xenopus laevis oocytes. ENaC cleavage and function were studied in TMPRSS2-deficient murine cortical collecting duct (mCCDcl1) cells and TMPRSS2-knockout (Tmprss2-/-) mice. Short-circuit currents (ISC) were measured to assess ENaC-mediated transepithelial sodium transport of mCCDcl1 cells. The mCCDcl1 cell transcriptome was studied using RNA sequencing. The effect of low-sodium diet with or without high potassium were compared in Tmprss2-/- and wildtype mice using metabolic cages. ENaC-mediated whole-cell currents were recorded from microdissected tubules of Tmprss2-/- and wildtype mice. RESULTS: In oocytes, co-expression of murine TMPRSS2 and ENaC resulted in fully cleaved γ-ENaC and ∼2-fold stimulation of ENaC currents. High baseline expression of TMPRSS2 was detected in mCCDcl1 cells without a stimulatory effect of aldosterone on its function or transcription. TMPRSS2 knockout in mCCDcl1 cells compromised γ-ENaC cleavage and reduced baseline and aldosterone-stimulated ISC which could be rescued by chymotrypsin. A compensatory transcriptional upregulation of other proteases was not observed. Tmprss2-/- mice kept on standard diet exhibited no apparent phenotype, but renal γ-ENaC cleavage was altered. In response to a low-salt diet, particularly with high potassium intake, Tmprss2-/- mice increased plasma aldosterone significantly more than wildtype mice to achieve a similar reduction of renal sodium excretion. Importantly, the stimulatory effect of trypsin on renal tubular ENaC currents was much more pronounced in Tmprss2-/- mice than that in wildtype mice. This indicated the presence of incompletely cleaved and less active channels at the cell surface of TMPRSS2-deficient tubular epithelial cells. CONCLUSIONS: TMPRSS2 contributes to proteolytic ENaC activation in mouse kidney in vivo.
Altmetric
Additional Metrics?
[➜Log in]
Edit extra informations Login
Publication type Article: Journal article
Document type Scientific Article
Corresponding Author
Keywords aldosterone; BP; cell and transport physiology; collecting ducts; electrophysiology; ENaC; epithelial sodium channel; ion transport; transgenic mouse; kidney biology and physiology; Gamma-subunit; Na+ Channel; Inhibitory Domain; Alpha-subunit; Enac; Tmprss2; Expression; Proteinase; Maturation; Cleavage
ISSN (print) / ISBN 1046-6673
e-ISSN 1533-3450
Journal Journal of the American Society of Nephrology
Publisher American Society of Nephrology
Publishing Place 1401 H Street Nw, Suite 900, Washington, Dc 20005, United States
Non-patent literature Publications
Reviewing status Peer reviewed
Institute(s) Institute of Diabetes Research and Metabolic Diseases (IDM)
Grants Bundesministerium fur Bildung und Forschung (SENSE-CoV2)
IZKF program of the Medical Faculty Tubingen
Interdisziplinaeres Zentrum fur klinische Forschung (IZKF) Erlangen
Bayerisches Staatsministerium fur Wissenschaft und Kunst (project VI-Corona-Forschung)
Deutsche Forschungsgemeinschaft