Department of Anesthesiology, College of Physicians and Surgeons of Columbia University, New York, NY, USA.
Department of Pathology, College of Physicians and Surgeons of Columbia University, New York, NY, USA.
FASEB J. 2020 Apr;34(4):5465-5482. doi: 10.1096/fj.201903287R. Epub 2020 Feb 21.
We tested the hypothesis that the P2X4 purinergic receptor (P2X4) exacerbates ischemic acute kidney injury (AKI) by promoting renal tubular inflammation after ischemia and reperfusion (IR). Supporting this, P2X4-deficient (KO) mice were protected against ischemic AKI with significantly attenuated renal tubular necrosis, inflammation, and apoptosis when compared to P2X4 wild-type (WT) mice subjected to renal IR. Furthermore, WT mice treated with P2X4 allosteric agonist ivermectin had exacerbated renal IR injury whereas P2X4 WT mice treated with a selective P2X4 antagonist (5-BDBD) were protected against ischemic AKI. Mechanistically, induction of kidney NLRP3 inflammasome signaling after renal IR was significantly attenuated in P2X4 KO mice. A P2 agonist ATPγS increased NLRP3 inflammasome signaling (NLRP3 and caspase 1 induction and IL-1β processing) in isolated renal proximal tubule cells from WT mice whereas these increases were absent in renal proximal tubules isolated from P2X4 KO mice. Moreover, 5-BDBD attenuated ATPγS induced NLRP3 inflammasome induction in renal proximal tubules from WT mice. Finally, P2X4 agonist ivermectin induced NLRP3 inflammasome and pro-inflammatory cytokines in cultured human proximal tubule cells. Taken together, our studies suggest that renal proximal tubular P2X4 activation exacerbates ischemic AKI and promotes NLRP3 inflammasome signaling.
我们检验了这样一个假设，即 P2X4 嘌呤能受体（P2X4）通过在缺血再灌注（IR）后促进肾小管炎症而加剧缺血性急性肾损伤（AKI）。支持这一假设的是，与接受肾 IR 的 P2X4 野生型（WT）小鼠相比，P2X4 缺陷型（KO）小鼠对缺血性 AKI 具有保护作用，肾小管坏死、炎症和细胞凋亡明显减轻。此外，用 P2X4 别构激动剂伊维菌素治疗的 WT 小鼠加重了肾 IR 损伤，而用选择性 P2X4 拮抗剂（5-BDBD）治疗的 P2X4 WT 小鼠则对缺血性 AKI 具有保护作用。在机制上，肾 IR 后肾脏 NLRP3 炎性小体信号的诱导在 P2X4 KO 小鼠中明显减弱。P2 激动剂 ATPγS 增加了来自 WT 小鼠的分离肾近端小管细胞中的 NLRP3 炎性小体信号（NLRP3 和 caspase 1 诱导和 IL-1β 加工），而在从 P2X4 KO 小鼠分离的肾近端小管中则没有这种增加。此外，5-BDBD 减弱了 WT 小鼠肾近端小管中 ATPγS 诱导的 NLRP3 炎性小体诱导。最后，P2X4 激动剂伊维菌素在培养的人近端肾小管细胞中诱导 NLRP3 炎性小体和促炎细胞因子。总之，我们的研究表明，肾脏近端小管 P2X4 的激活加剧了缺血性 AKI，并促进了 NLRP3 炎性小体信号。
