Uromodulin upregulates TRPV5 by impairing caveolin-mediated endocytosis

Matthias T F Wolf, Xue Ru Wu, Chou Long Huang

Research output: Contribution to journalArticlepeer-review

52 Scopus citations

Abstract

Uromodulin (UMOD) is synthesized in the thick ascending limb and secreted into urine as the most abundant protein. Association studies in humans suggest protective effects of UMOD against calcium-containing kidney stones. Mice carrying mutations of Umod found in human UMOD-associated kidney disease (UAKD) and Umod-deficient mice exhibit hypercalciuria. The mechanism for UMOD regulation of urinary Ca 2+ excretion is incompletely understood. We examined if UMOD regulates TRPV5 and TRPV6, channels critical for renal transcellular Ca 2+ reabsorption. Coexpression with UMOD increased whole-cell TRPV5 current density in HEK293 cells. In biotinylation studies, UMOD increased TRPV5 cell-surface abundance. Extracellular application of purified UMOD upregulated TRPV5 current density within physiological relevant concentration ranges. UMOD exerted a similar effect on TRPV6. TRPV5 undergoes constitutive caveolin-mediated endocytosis. UMOD had no effect on TRPV5 in a caveolin-1-deficient cell line. Expression of recombinant caveolin-1 in these cells restored the ability of UMOD to upregulate TRPV5. Secretion of UAKD-mutant UMOD was markedly reduced and coexpression of mutant UMOD with TRPV5 failed to increase its current. Immunofluorescent studies demonstrated lower TRPV5 expression in Umod -/- mice compared with wild-type. UMOD upregulates TRPV5 by acting from extracellular and by decreasing endocytosis of TRPV5. The stimulation of Ca 2+ reabsorption via TRPV5 by UMOD may contribute to protection against kidney-stone formation.

Original languageEnglish (US)
Pages (from-to)130-137
Number of pages8
JournalKidney international
Volume84
Issue number1
DOIs
StatePublished - Jul 2013

ASJC Scopus subject areas

  • Nephrology

Fingerprint

Dive into the research topics of 'Uromodulin upregulates TRPV5 by impairing caveolin-mediated endocytosis'. Together they form a unique fingerprint.

Cite this