高尿酸血症(HUA)可激活结合核苷酸的寡聚化结构域样受体蛋白3(NLRP3)炎症小体，导致内皮细胞功能障碍，引起内皮损伤，但机制不明。本研究拟探究尿酸(UA)是否通过活性氧(ROS)影响炎症小体的表观调控和激活、从而导致内皮损害。

600 μmol/L UA处理人脐静脉内皮细胞(HUVEC)24 h，Western印迹检测焦亡相关蛋白的表达变化，包括NLRP3、半胱氨酸天冬氨酸蛋白水解酶1(Caspase-1)、消皮素D氨基端蛋白(GSDMD-N)；ELISA法检测细胞上清乳酸脱氢酶(LDH)、白细胞介素-1β(IL-1β)和白细胞介素-18(IL-18)。通过功能获得和缺失实验，验证NLRP3炎症小体在高尿酸导致的内皮细胞焦亡中的作用；利用免疫沉淀(IP)检测高尿酸环境中氧化应激相关蛋白硫氧还蛋白互作蛋白(TXNIP)、硫氧还蛋白(TRX)和NLRP3的相互作用。利用慢病毒过表达和敲低TXNIP，进一步验证TXNIP对NLRP3的调控关系，及其对内皮细胞焦亡的影响。

高尿酸处理的HUVEC的焦亡相关蛋白(NLRP3、Caspase-1、GSDMD-N)表达升高，细胞上清LDH及炎症因子IL-1β，IL-18的释放增加，HUVEC增殖明显受到抑制。功能获得和缺失实验证实高尿酸通过NLRP3炎症小体导致内皮细胞焦亡。使用ROS清除剂mito-Tempo处理HUVEC细胞，可抑制TXNIP/TRX的解离，从而阻断TXNIP和NLRP3之间的相互作用，最终抑制NLRP3炎症小体激活和焦亡发生。过表达TXNIP，可导致NLRP3激活及后续焦亡发生，而敲低TXNIP，则观察到相反的结果。

本研究证实高尿酸导致内皮细胞炎症反应及后续的焦亡发生，是通过ROS促进了TXNIP/TRX解离，随后激活了NLRP3炎症小体。

Hyperuricemia can lead to the activation of NLRP3 inflammasomes, resulting in the dysfunction and injury of endothelial cells, but the mechanism is unclear. This study aimed to explore whether uric acid (UA) could affect the epigenetic regulation and activation of inflammasomes through reactive oxygen species (ROS), leading to the endothelial damage.

Human umbilical vein endothelial cells (HUVEC) were cultured with UA (600 μmol/L) for 24 hours. Western blot was used to determine expression changes of pyroptosis-related proteins including NLRP3, caspase-1, and GSDMD-N. The levels of LDH, IL-1β, and IL-18 in the cells supernatant were detected by ELISA. The gain-of-function and loss-of-function experiments were performed to verify the role of NLRP3 inflammasomes in the pyroptosis of endothelial cells induced by high uric acid. Immunoprecipitation method was used to detect the interaction among oxidative stress-related proteins of TXNIP, TRX, and NLRP3 in the high uric acid environment. Overexpression and knock-down of TXNIP with lentivirus were used to further verify the regulation of NLRP3 by TXNIP, as well as its effect on pyroptosis of endothelial cells.

The expression of pyroptosis-related proteins as NLRP3, caspase-1, and GSDMD-N in HUVEC treated with UA was increased, while the release of LDH, IL-1β, and IL-18 in the cells supernatant was also increased, with the proliferation of HUVEC being significantly inhibited. Gain-of-function and loss-of-function experiments confirmed that high uric acid led to pyroptosis of endothelial cells via NLRP3 inflammasomes. Treating the HUVEC with the ROS scavenger mito-Tempo inhibited the dissociation of TXNIP/TRX, thereby blocked the interaction between TXNIP and NLRP3, eventually resulting in inhibiting both the activation of NLRP3 inflammasomes and pyroptosis. Overexpression of TXNIP led to the activation of NLRP3 and subsequent pyroptosis, while knock-down of TXNIP caused the opposite results.

This study demonstrated that high uric acid caused inflammation and subsequent pyroptosis of the endothelial cells through ROS promoting the dissociation of TXNIP/TRX and then activating the NLRP3 inflammasomes.