Edinburgh Kidney, British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh, UK.
Sci Rep. 2024 Apr 26;14(1):9573. doi: 10.1038/s41598-024-59635-x.
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.
P2X7 受体介导细胞外 ATP 引起的免疫和内皮细胞反应。急性药理学阻断可增加肾血流量和滤过率，表明受体激活促进了持续的血管收缩。在肾脏疾病中 P2X7 的表达增加，阻断/敲除具有肾脏保护作用。我们在 F344 背景下生成了 P2X7 敲除大鼠，假设其可增强肾血流量并预防血管紧张素 II 诱导的肾损伤。CRISPR/Cas9 在 P2rx7 的外显子 2 中引入了一个提前终止密码子，从而在肾脏中消除了 P2X7 蛋白，并使骨髓来源的巨噬细胞中 P2rx7 mRNA 的丰度降低了约 60%。对脂多糖的 M1 极化反应不受影响，但 P2X7 受体敲除抑制了 ATP 诱导的 IL-1β 释放。在雄性敲除大鼠中，肾动脉的乙酰胆碱诱导扩张在体外减少，但对硝普钠的反应不受影响。雄性和雌性敲除大鼠的肾功能与野生型大鼠无差异。最后，在接受血管紧张素 II 输注 6 周的雄性大鼠中，P2X7 敲除并未减少蛋白尿、肾小管损伤、肾巨噬细胞积聚和肾血管周围纤维化。与我们的假设相反，全身 P2X7 敲除对体内肾血流动力学没有影响。我们的研究表明 P2X7 受体激活在肾血管损伤中没有主要作用。
