Colocalization of the (Pro)renin Receptor/Atp6ap2 with H+-ATPases in Mouse Kidney but Prorenin Does Not Acutely Regulate Intercalated Cell H+-ATPase Activity

PLoS One. 2016 Jan 29;11(1):e0147831. doi: 10.1371/journal.pone.0147831. eCollection 2016.

Abstract

The (Pro)renin receptor (P)RR/Atp6ap2 is a cell surface protein capable of binding and non-proteolytically activate prorenin. Additionally, (P)RR is associated with H(+)-ATPases and alternative functions in H(+)-ATPase regulation as well as in Wnt signalling have been reported. Kidneys express very high levels of H(+)-ATPases which are involved in multiple functions such as endocytosis, membrane protein recycling as well as urinary acidification, bicarbonate reabsorption, and salt absorption. Here, we wanted to localize the (P)RR/Atp6ap2 along the murine nephron, exmaine whether the (P)RR/Atp6ap2 is coregulated with other H(+)-ATPase subunits, and whether acute stimulation of the (P)RR/Atp6ap2 with prorenin regulates H(+)-ATPase activity in intercalated cells in freshly isolated collecting ducts. We localized (P)PR/Atp6ap2 along the murine nephron by qPCR and immunohistochemistry. (P)RR/Atp6ap2 mRNA was detected in all nephron segments with highest levels in the collecting system coinciding with H(+)-ATPases. Further experiments demonstrated expression at the brush border membrane of proximal tubules and in all types of intercalated cells colocalizing with H(+)-ATPases. In mice treated with NH4Cl, NaHCO3, KHCO3, NaCl, or the mineralocorticoid DOCA for 7 days, (P)RR/Atp6ap2 and H(+)-ATPase subunits were regulated but not co-regulated at protein and mRNA levels. Immunolocalization in kidneys from control, NH4Cl or NaHCO3 treated mice demonstrated always colocalization of PRR/Atp6ap2 with H(+)-ATPase subunits at the brush border membrane of proximal tubules, the apical pole of type A intercalated cells, and at basolateral and/or apical membranes of non-type A intercalated cells. Microperfusion of isolated cortical collecting ducts and luminal application of prorenin did not acutely stimulate H(+)-ATPase activity. However, incubation of isolated collecting ducts with prorenin non-significantly increased ERK1/2 phosphorylation. Our results suggest that the PRR/Atp6ap2 may form a complex with H(+)-ATPases in proximal tubule and intercalated cells but that prorenin has no acute effect on H(+)-ATPase activity in intercalated cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ammonium Chloride / pharmacology
  • Animals
  • Anion Transport Proteins / genetics
  • Anion Transport Proteins / metabolism
  • Aquaporin 2 / genetics
  • Aquaporin 2 / metabolism
  • Cell Membrane / drug effects
  • Cell Membrane / metabolism
  • Dogs
  • Gene Expression Regulation
  • Kidney Cortex / cytology
  • Kidney Cortex / drug effects*
  • Kidney Cortex / metabolism
  • Kidney Medulla / cytology
  • Kidney Medulla / drug effects*
  • Kidney Medulla / metabolism
  • Kidney Tubules, Collecting / cytology
  • Kidney Tubules, Collecting / drug effects*
  • Kidney Tubules, Collecting / metabolism
  • Kidney Tubules, Proximal / cytology
  • Kidney Tubules, Proximal / drug effects*
  • Kidney Tubules, Proximal / metabolism
  • Madin Darby Canine Kidney Cells
  • Male
  • Membrane Glycoproteins / genetics
  • Membrane Glycoproteins / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Proton-Translocating ATPases / genetics*
  • Proton-Translocating ATPases / metabolism
  • Receptors, Cell Surface / genetics*
  • Receptors, Cell Surface / metabolism
  • Renin / pharmacology*
  • Renin-Angiotensin System / drug effects
  • Signal Transduction
  • Sodium Bicarbonate / pharmacology
  • Sodium Chloride / pharmacology
  • Sodium-Phosphate Cotransporter Proteins, Type IIa / genetics
  • Sodium-Phosphate Cotransporter Proteins, Type IIa / metabolism
  • Solute Carrier Family 12, Member 1 / genetics
  • Solute Carrier Family 12, Member 1 / metabolism
  • Solute Carrier Family 12, Member 3 / genetics
  • Solute Carrier Family 12, Member 3 / metabolism
  • Sulfate Transporters

Substances

  • ATP6AP2 protein, mouse
  • Anion Transport Proteins
  • Aqp2 protein, mouse
  • Aquaporin 2
  • Gp38 protein, mouse
  • Membrane Glycoproteins
  • Receptors, Cell Surface
  • Slc12a1 protein, mouse
  • Slc12a3 protein, mouse
  • Slc26a4 protein, mouse
  • Slc34a1 protein, mouse
  • Sodium-Phosphate Cotransporter Proteins, Type IIa
  • Solute Carrier Family 12, Member 1
  • Solute Carrier Family 12, Member 3
  • Sulfate Transporters
  • Ammonium Chloride
  • Sodium Chloride
  • Sodium Bicarbonate
  • Renin
  • Proton-Translocating ATPases

Grants and funding

This work was supported by the Swiss National Science Foundation (grant No. 31003A_138143) to C.A. Wagner and the Hartmann-Müller Stiftung (Zurich, Switzerland) to A. Daryadel. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.