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Updated: Jun 27, 2025
The Mouse Isolated Perfused Kidney Technique
Published on: November 17, 2016
P2X7 receptor knockout does not alter renal function or prevent angiotensin II-induced kidney injury in F344 rats
Josselin Nespoux1, Marie-Louise T Monaghan1, Natalie K Jones1
1Edinburgh Kidney, British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh, UK.
Abstract:
P2X7 receptors mediate immune and endothelial cell responses to extracellular ATP. Acute pharmacological blockade increases renal blood flow and filtration rate, suggesting that receptor activation promotes tonic vasoconstriction. P2X7 expression is increased in kidney disease and blockade/knockout is renoprotective. We generated a P2X7 knockout rat on F344 background, hypothesising enhanced renal blood flow and protection from angiotensin-II-induced renal injury. CRISPR/Cas9 introduced an early stop codon into exon 2 of P2rx7, abolishing P2X7 protein in kidney and reducing P2rx7 mRNA abundance by ~ 60% in bone-marrow derived macrophages. The M1 polarisation response to lipopolysaccharide was unaffected but P2X7 receptor knockout suppressed ATP-induced IL-1β release. In male knockout rats, acetylcholine-induced dilation of the renal artery ex vivo was diminished but not the response to nitroprusside. Renal function in male and female knockout rats was not different from wild-type. Finally, in male rats infused with angiotensin-II for 6 weeks, P2X7 knockout did not reduce albuminuria, tubular injury, renal macrophage accrual, and renal perivascular fibrosis. Contrary to our hypothesis, global P2X7 knockout had no impact on in vivo renal hemodynamics. Our study does not indicate a major role for P2X7 receptor activation in renal vascular injury.
Insights
P2X7 receptor knockout in rats did not improve kidney blood flow or protect against angiotensin-II induced injury. These findings suggest P2X7 receptor activation is not a major factor in renal vascular injury.
Area of Science:
- Immunology
- Nephrology
- Pharmacology
Background:
- P2X7 receptors respond to extracellular ATP and are implicated in immune and endothelial cell functions.
- Increased P2X7 receptor expression is observed in kidney disease, with blockade/knockout showing potential renoprotective effects.
- The role of P2X7 receptors in renal hemodynamics and injury requires further investigation.
Purpose of the Study:
- To investigate the role of P2X7 receptors in renal hemodynamics and angiotensin-II induced renal injury.
- To generate and characterize a P2X7 receptor knockout rat model.
- To determine if P2X7 receptor deficiency confers protection against renal damage.
Main Methods:
- Generated a P2X7 receptor knockout rat using CRISPR/Cas9 technology.
- Assessed P2X7 protein and mRNA levels in knockout rats.
- Evaluated renal artery vasodilation responses ex vivo and in vivo renal function.
- Infused male rats with angiotensin-II to induce renal injury and assessed P2X7 knockout impact.
Main Results:
- P2X7 receptor knockout abolished P2X7 protein and reduced P2X7 mRNA in macrophages, but did not affect M1 polarization.
- ATP-induced IL-1β release was suppressed in knockout rats.
- Ex vivo renal artery dilation to acetylcholine was diminished in knockout rats.
- Global P2X7 knockout did not alter in vivo renal hemodynamics or protect against angiotensin-II induced albuminuria, tubular injury, macrophage accrual, or fibrosis.
Conclusions:
- Global P2X7 receptor knockout does not significantly impact in vivo renal hemodynamics.
- P2X7 receptor deficiency does not protect against angiotensin-II induced renal injury in rats.
- The study does not support a major role for P2X7 receptor activation in renal vascular injury.
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