Equilibrative nucleoside transporter 1 (ENT1) regulates postischemic blood flow during acute kidney injury in mice

J Clin Invest. 2012 Feb;122(2):693-710. doi: 10.1172/JCI60214. Epub 2012 Jan 24.

Abstract

A complex biologic network regulates kidney perfusion under physiologic conditions. This system is profoundly perturbed following renal ischemia, a leading cause of acute kidney injury (AKI) - a life-threatening condition that frequently complicates the care of hospitalized patients. Therapeutic approaches to prevent and treat AKI are extremely limited. Better understanding of the molecular pathways promoting postischemic reflow could provide new candidate targets for AKI therapeutics. Due to its role in adapting tissues to hypoxia, we hypothesized that extracellular adenosine has a regulatory function in the postischemic control of renal perfusion. Consistent with the notion that equilibrative nucleoside transporters (ENTs) terminate adenosine signaling, we observed that pharmacologic ENT inhibition in mice elevated renal adenosine levels and dampened AKI. Deletion of the ENTs resulted in selective protection in Ent1-/- mice. Comprehensive examination of adenosine receptor-knockout mice exposed to AKI demonstrated that renal protection by ENT inhibitors involves the A2B adenosine receptor. Indeed, crosstalk between renal Ent1 and Adora2b expressed on vascular endothelia effectively prevented a postischemic no-reflow phenomenon. These studies identify ENT1 and adenosine receptors as key to the process of reestablishing renal perfusion following ischemic AKI. If translatable from mice to humans, these data have important therapeutic implications.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Retracted Publication

MeSH terms

  • Acute Kidney Injury / drug therapy
  • Acute Kidney Injury / metabolism*
  • Acute Kidney Injury / pathology
  • Adenosine / metabolism
  • Animals
  • Cell Line
  • Chimerism
  • Dipyridamole / therapeutic use
  • Equilibrative Nucleoside Transporter 1 / antagonists & inhibitors
  • Equilibrative Nucleoside Transporter 1 / genetics
  • Equilibrative Nucleoside Transporter 1 / metabolism*
  • Humans
  • Ischemia / metabolism*
  • Kidney / metabolism
  • Kidney / pathology
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • No-Reflow Phenomenon
  • Nucleoside Transport Proteins / antagonists & inhibitors
  • Nucleoside Transport Proteins / metabolism
  • Phosphodiesterase Inhibitors / therapeutic use
  • Receptors, Purinergic P1 / genetics
  • Receptors, Purinergic P1 / metabolism
  • Regional Blood Flow / physiology*

Substances

  • Equilibrative Nucleoside Transporter 1
  • Nucleoside Transport Proteins
  • Phosphodiesterase Inhibitors
  • Receptors, Purinergic P1
  • adenosine transporter
  • Dipyridamole
  • Adenosine