Uromodulin regulates renal magnesium homeostasis through the ion channel transient receptor potential melastatin 6 (TRPM6)

Mingzhu Nie, Manjot S. Bal, Jie Liu, Zhufeng Yang, Carolina Rivera, Xue Ru Wu, Joost G.J. Hoenderop, René J.M. Bindels, Denise K. Marciano, Matthias T.F. Wolf

Research output: Contribution to journalArticle

5 Scopus citations

Abstract

Up to 15% of the population have mild to moderate chronic hypomagnesemia, which is associated with type 2 diabetes mellitus, hypertension, metabolic syndrome, and chronic kidney disease. The kidney is the key organ for magnesium homeostasis, but our understanding of renal magnesium regulation is very limited. Uromodulin (UMOD) is the most abundant urinary protein in humans, and here we report that UMOD has a role in renal magnesium homeostasis. Umod-knockout (Umod/) mice excreted more urinary magnesium than WT mice and displayed up-regulation of genes promoting magnesium absorption. The majority of magnesium is absorbed in the thick ascending limb. However, both mouse strains responded similarly to the diuretic agent furosemide, indicating appropriate function of the thick ascending limb in the Umod/mice. Magnesium absorption is fine-tuned in the distal convoluted tubule (DCT) via the apical magnesium channel transient receptor potential melastatin 6 (TRPM6). We observed decreased apical Trpm6 staining in the DCT of Umod/mice. Applying biotinylation assays and whole-cell patch-clamp recordings, we found that UMOD enhances TRPM6 cell-surface abundance and current density from the extracellular space. UMOD physically interacted with TRPM6 and thereby impaired dynamindependent TRPM6 endocytosis. WT mice fed a low-magnesium diet had an increased urinary UMOD secretion compared with the same mice on a regular diet. Our results suggest that increased urinary UMOD secretion in low-magnesium states reduces TRPM6 endocytosis and thereby up-regulates TRPM6 cell-surface abundance to defend against further urinary magnesium losses.

Original languageEnglish (US)
Pages (from-to)16488-16502
Number of pages15
JournalJournal of Biological Chemistry
Volume293
Issue number42
DOIs
StatePublished - Oct 19 2018

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Fingerprint Dive into the research topics of 'Uromodulin regulates renal magnesium homeostasis through the ion channel transient receptor potential melastatin 6 (TRPM6)'. Together they form a unique fingerprint.

  • Cite this