P2X7 deficiency attenuates hypertension and renal injury in deoxycorticosterone acetate-salt hypertension

Am J Physiol Renal Physiol. 2012 Oct 15;303(8):F1207-15. doi: 10.1152/ajprenal.00051.2012. Epub 2012 Aug 1.

Abstract

The P2X(7) receptor is a ligand-gated ion channel, and genetic variations in the P2X(7) gene significantly affect blood pressure. P2X(7) receptor expression is associated with renal injury and inflammatory diseases. Uninephrectomized wild-type (WT) and P2X(7)-deficient (P2X(7) KO) mice were subcutaneously implanted with deoxycorticosterone acetate (DOCA) pellets and fed an 8% salt diet for 18 days. Their blood pressure was assessed by a telemetry system. The mice were placed in metabolic cages, and urine was collected for 24 h to assess renal function. After 18 days of DOCA-salt treatment, P2X(7) mRNA and protein expression increased in WT mice. Blood pressure in P2X(7) KO mice was less than that of WT mice (mean systolic blood pressure 133 ± 3 vs. 150 ± 2 mmHg). On day 18, urinary albumin excretion was lower in P2X(7) KO mice than in WT mice (0.11 ± 0.07 vs. 0.28 ± 0.07 mg/day). Creatinine clearance was higher in P2X(7) KO mice than in WT mice (551.53 ± 65.23 vs. 390.85 ± 32.81 μl·min(-1)·g renal weight(-1)). Moreover, renal interstitial fibrosis and infiltration of immune cells (macrophages, T cells, B cells, and leukocytes) were markedly attenuated in P2X(7) KO mice compared with WT mice. The levels of IL-1β, released by macrophages, in P2X(7) KO mice had decreased dramatically compared with that in WT mice. These results strongly suggest that the P2X(7) receptor plays a key role in the development of hypertension and renal disease via increased inflammation, indicating its potential as a novel therapeutic target.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Albuminuria / complications
  • Albuminuria / metabolism
  • Albuminuria / physiopathology
  • Animals
  • Blood Pressure / drug effects
  • Blood Pressure / physiology
  • Desoxycorticosterone / pharmacokinetics*
  • Heart Rate / drug effects
  • Heart Rate / physiology
  • Hypertension / complications
  • Hypertension / metabolism*
  • Hypertension / physiopathology
  • Interleukin-1beta / metabolism
  • Kidney / drug effects
  • Kidney / metabolism*
  • Kidney / physiopathology
  • Kidney Diseases / complications
  • Kidney Diseases / metabolism
  • Kidney Diseases / physiopathology
  • Male
  • Mice
  • Mice, Knockout
  • Receptors, Purinergic P2X7 / genetics*
  • Receptors, Purinergic P2X7 / metabolism
  • Sodium Chloride, Dietary / pharmacology*

Substances

  • Interleukin-1beta
  • Receptors, Purinergic P2X7
  • Sodium Chloride, Dietary
  • Desoxycorticosterone