TXNIP介导的NLRP3炎症小体激活在心肌微血管内皮细胞缺氧/复氧损伤中的作用

目的 研究硫氧还蛋白结合蛋白（TXNIP）介导的NLRP3炎症小体激活在心肌微血管内皮细胞（CMECs）缺氧/复氧（H/R）损伤中的作用。方法 分离培养C57BL/6J小鼠CMECs，随机分为对照组、H/R损伤组、H/R+Scrambled siRNA组和H/R+TXNIP siRNA组。各组处理后使用ELISA试剂盒检测细胞IL-1β水平，采用免疫共沉淀的方法检测TXNIP和NLRP3的相互作用，Western blot检测TXNIP和NLRP3的表达水平，乳酸脱氢酶试剂盒检测细胞培养上清LDH释放情况和细胞Caspase-3活性。结果 与对照组相比，H/R后CMECs的NLRP3表达水平明显升高（P<0.05），NLRP3炎症小体激活（IL-1β水平升高，P<0.01），且TXNIP和NLRP3的结合效果明显增强（P<0.01）。运用TXNIP siRNA抑制TXNIP表达后行H/R处理，与H/R+Scrambled siRNA组相比，NLRP3炎症小体激活水平明显下降（IL-1β水平降低），细胞Caspase-3活力和LDH释放水平均显著降低（均P<0.05）。结论 在CMECs发生H/R损伤时，NLRP3炎症小体激活，TXNIP和NLRP3的相互作用增强；抑制TXNIP表达后，NLRP3炎症小体激活水平降低，内皮损伤减轻。说明TXNIP介导的NLRP3炎症小体激活参与CMECs的H/R损伤，可能成为CMECs的H/R损伤的新机制。

Effect of TXNIP mediated NLRP3 inflammasome activation on cardiac microvascular endothelial cells during hypoxia/reoxygenation injury

AIM To determine the effect of thioredoxin-interacting protein (TXNIP) mediated NLRP3 inflammasome activation on cardiac microvascular endothelial cells (CMECs) during hypoxia/reoxygenation (H/R) injury. METHODS CMECs isolated from the hearts of adult mice were randomized into control group, H/R group, H/R+scrambled siRNA group and H/R+TXNIP siRNA group. Levels of IL-1β were detected by ELISA kits. The interaction between TXNIP and NLRP3 was determined by immunoprecipitation. Expressions of TXNIP and NLRP3 were analyzed by Western blot, and caspase-3 activity and LDH release were assessed with test kits. RESULTS H/R increased NLRP3 expression (P<0.05), IL-1β level (P<0.01) and the interaction between TXNIP and NLRP3 (P<0.01) in CMECs compared with control group. Blocking TXNIP signaling with siRNA significantly inhibited NLRP3 activation (P<0.05) and alleviated endothelial injury evidenced by increased caspase-3 activity LDH release (P<0.05). CONCLUSION H/R injury promotes NLRP3 activation and increases the interaction between TXNIP and NLRP3. Blocking TXNIP signaling reduces NLRP3 activation and endothelial injury. TXNIP mediated NLRP3 activation may be a novel mechanism in H/R injury of CMECs.