Department of Urology, Nanjing First Hospital, Nanjing Medical University, 68 Changle Road, Nanjing, 210006, China.
Department of Urology, The Second Affiliated Hospital of Nanjing Medical University, 121#, Jiangjiayuan, Nanjing, 210000, China.
Int Urol Nephrol. 2022 Dec;54(12):3097-3106. doi: 10.1007/s11255-022-03347-6. Epub 2022 Sep 10.
To investigate whether cystine crystal-induced production of reactive oxygen species (ROS) and activation of NLRP3 inflammasome contribute to cystine calculi formation.
Slc7a9-knockout rats were created as cystine calculi animal models. Kidney histological examination using TEM and immunohistochemistry were performed. The protein expression of NLRP3 and IL-1β and the concentrations of oxidative stress markers such as ROS, MDA and H2O2 in kidney tissues were estimated. In parallel, HK-2 human renal proximal tubule cells were exposed to cystine crystals and NAC treatment. The protein and mRNA expression levels of NLRP3 were evaluated. Finally, cell apoptosis and cystine crystal adherence were also assessed.
Activation of the NLRP3 inflammasome and marked elevations in MDA, H2O2 and ROS levels were observed both in vivo and in vitro. In particular, the protein and mRNA expression of NLRP3 was significantly increased by cystine crystals, but could be restored by an inhibitor of ROS. In addition, cell apoptosis and cystine crystal adherence were promoted by the NLRP3 inflammasome. The expression of CD44, OPN and HA in HK-2 cells was markedly increased by cystine crystals, but could be decreased by NLRP3 siRNA treatment.
Notably, we found that the activation of NLRP3 by cystine crystal-induced ROS production was of major importance in the pathogenesis of cystine calculi formation.
研究胱氨酸晶体诱导活性氧（ROS）的产生和 NLRP3 炎性体的激活是否有助于胱氨酸结石的形成。
构建 Slc7a9 敲除大鼠作为胱氨酸结石动物模型。采用 TEM 和免疫组织化学法进行肾脏组织学检查。评估 NLRP3 和 IL-1β 的蛋白表达以及肾组织中氧化应激标志物如 ROS、MDA 和 H2O2 的浓度。同时，将 HK-2 人肾小管近端细胞暴露于胱氨酸晶体和 NAC 处理。评估 NLRP3 的蛋白和 mRNA 表达水平。最后，还评估了细胞凋亡和胱氨酸晶体附着。
在体内和体外均观察到 NLRP3 炎性体的激活和 MDA、H2O2 和 ROS 水平的显著升高。特别是，胱氨酸晶体显著增加了 NLRP3 的蛋白和 mRNA 表达，但可以通过 ROS 抑制剂恢复。此外，细胞凋亡和胱氨酸晶体附着均由 NLRP3 炎性体促进。胱氨酸晶体显著增加了 HK-2 细胞中 CD44、OPN 和 HA 的表达，但可以通过 NLRP3 siRNA 处理降低。
值得注意的是，我们发现胱氨酸晶体诱导 ROS 产生激活 NLRP3 在胱氨酸结石形成的发病机制中具有重要意义。
