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NEDD4‐2 reduces electroneutral Cl − /HCO 3 − exchange in mouse cortical collecting duct
Author(s) -
Pham Truyen Derek,
Nanami Masayoshi,
Staub Olivier,
Sutliff Roy L,
Klein Janet D,
Eladari Dominique,
Chambrey Regine,
Wang Xiaonan,
Verlander Jill W,
Wall Susan M
Publication year - 2016
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.30.1_supplement.965.8
Subject(s) - nedd4 , chemistry , pendrin , microbiology and biotechnology , epithelial sodium channel , distal convoluted tubule , sgk1 , endocytosis , reabsorption , ubiquitin ligase , ubiquitin , biochemistry , biology , cell , transporter , sodium , gene , organic chemistry
NEDD4‐2 is a ubiquitin ligase that associates with transport proteins, such as ENaC, resulting in their ubiquitination and then endocytosis and degradation. With global NEDD4‐2 gene ablation, salt‐sensitive hypertension is observed, in part, from the increased renal NaCl transporter expression. While principal cell NEDD4‐2 function has been studied, little is known about NEDD4‐2 within intercalated cells (ICs). Thus, the purpose of this study was to determine the effect of IC NEDD4‐2 ablation on blood pressure and on Cl − absorption in the cortical collecting duct (CCD). As such, we generated an IC‐specific NEDD4‐2 null mouse using Cre‐loxP technology. Blood pressure was measured by radiotelemetry and ion transport was measured in mouse cortical collecting ducts (CCDs) perfused in vitro. Following a high NaCl diet, IC NEDD4‐2 gene ablation markedly stimulated electroneutral Cl − /HCO 3 − exchange in the mouse CCD and increased mean arterial pressure by ~10 mm Hg. To determine the transporter(s) responsible for this increase in transport, we examined the effect of IC NEDD4‐2 gene ablation on mouse type B IC transporter abundance by immunoblot, immunohistochemistry and immunogold cytochemistry. We observed that IC NEDD4‐2 gene ablation increased ClC‐5 and pendrin protein abundance, but not the H + ‐ATPase, AE4 or the Na + ‐dependent Cl − /HCO 3 − exchanger, NDCBE. To determine if pendrin associates with NEDD4‐2 we transfected a rat intercalated cell line with adenovirus expressing Xpress‐tagged NEDD4‐2 and then immunoprecipitated for the Xpress tag. By immunoblot, pendrin was expressed in the Xpress tagged precipitates taken from cells transfected with full length NEDD4‐2, but not in precipitates taken from cells transfected with NEDD4‐2 lacking the C terminus. Conclusions IC NEDD4‐2 gene ablation contributes to the pathophysiology of salt‐sensitive hypertension, at least in part, by increasing Cl − absorption by ICs, through transporters such as pendrin. Support or Funding Information Interaction of NEDD4‐2 and Aldosterone in Interacalated Cell Function. Grant Number: DK104125