The renal TRPV4 channel is essential for adaptation to increased dietary potassium

Mykola V. Mamenko, Nabila Boukelmoune, Viktor N. Tomilin, Oleg L. Zaika, V. Behrana Jensen, Roger G. O'Neil, Oleh M. Pochynyuk

Research output: Contribution to journalArticle

17 Scopus citations

Abstract

To maintain potassium homeostasis, kidneys exert flow-dependent potassium secretion to facilitate kaliuresis in response to elevated dietary potassium intake. This process involves stimulation of calcium-activated large conductance maxi-K (BK) channels in the distal nephron, namely the connecting tubule and the collecting duct. Recent evidence suggests that the TRPV4 channel is a critical determinant of flow-dependent intracellular calcium elevations in these segments of the renal tubule. Here, we demonstrate that elevated dietary potassium intake (five percent potassium) increases renal TRPV4 mRNA and protein levels in an aldosterone-dependent manner and causes redistribution of the channel to the apical plasma membrane in native collecting duct cells. This, in turn, leads to augmented TRPV4-mediated flow-dependent calcium ion responses in freshly isolated split-opened collecting ducts from mice fed the high potassium diet. Genetic TRPV4 ablation greatly diminished BK channel activity in collecting duct cells pointing to a reduced capacity to excrete potassium. Consistently, elevated potassium intake induced hyperkalemia in TRPV4 knockout mice due to deficient renal potassium excretion. Thus, regulation of TRPV4 activity in the distal nephron by dietary potassium is an indispensable component of whole body potassium balance.

Original languageEnglish (US)
Pages (from-to)1398-1409
Number of pages12
JournalKidney International
Volume91
Issue number6
DOIs
StatePublished - Jun 2017

Keywords

  • BK channels
  • [Ca] signaling
  • aldosterone
  • distal nephron
  • flow-induced potassium secretion

ASJC Scopus subject areas

  • Nephrology

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  • Cite this

    Mamenko, M. V., Boukelmoune, N., Tomilin, V. N., Zaika, O. L., Jensen, V. B., O'Neil, R. G., & Pochynyuk, O. M. (2017). The renal TRPV4 channel is essential for adaptation to increased dietary potassium. Kidney International, 91(6), 1398-1409. https://doi.org/10.1016/j.kint.2016.12.010