Hou Yanghao, Wang Yueting, He Qi, Li Lingyu, Xie Hui, Zhao Yong, Zhao Jing
Department of Pathophysiology, Chongqing Medical University, Chongqing, People's Republic of China.
Department of Pathology, Chongqing Medical University, Chongqing, People's Republic of China.
Behav Brain Res. 2018 Jan 15;336:32-39. doi: 10.1016/j.bbr.2017.06.027. Epub 2017 Aug 26.
The nod-like receptor protein 3 (NLRP3) inflammasome has a critical role in inflammation damage in ischemic injury, and the activation of the inflammasome is closely related to the interaction with thioredoxin interacting protein (TXNIP), which dissociates from the thioredoxin1 (Trx1)/TXNIP complex under oxidative stress. However, the negative regulator of NLRP3 inflammasome activation has not been fully investigated. Nuclear factor erythroid 2-related factor 2 (Nrf2) takes on a critical part in the antioxidant stress system, that controls the driven genes of antioxidant response element (ARE). Activate Nrf2 could inhibit the activation of NLRP3 inflammasome in acute liver injury and severe lupus nephritis. We aimed to explore the protective effect of Nrf2 in inhibiting the NLPR3 inflammasome formulation through the Trx1/TXNIP complex in cerebral ischemia reperfusion (cerebral I/R) injury. Middle cerebral artery occlusion/reperfusion (MCAO/R) model was used to imitate ischemic insult. Nrf2 was activated by tert-butylhydroquinone (tBHQ) intraperitoneally (i.p.) injection (16.7mg/kg), Nrf2,Trx1 and NLRP3 siRNAs were infused into the left paracele (12μl per rat), protein and mRNA levels were assessed by Western blot, qRT-PCR. ELISA was used for IL-1β and IL-18 activity measurements. After upregulating Nrf2, the expression of TXNIP in cytoplasm, NLRP3 inflammasome, and downstream factors caspase-1, IL-18, and IL-1β were significantly reduced, and Nrf2 knockdown yielded the opposite results. Trx1 knockdown produced the same effect of Nrf2 inhibition and the protective effect of Nrf2 was mostly abolished. Our results suggested that Nrf2 acted as a protective regulator against NLRP3 inflammasome activation by regulating the Trx1/TXNIP complex, which could possibly represent an innovative insight into the treatment of ischemia and reperfusion injury.
核苷酸结合寡聚化结构域样受体蛋白3（NLRP3）炎性小体在缺血性损伤的炎症损害中起关键作用，且炎性小体的激活与硫氧还蛋白相互作用蛋白（TXNIP）的相互作用密切相关，TXNIP在氧化应激下从硫氧还蛋白1（Trx1）/TXNIP复合物上解离。然而，NLRP3炎性小体激活的负调节因子尚未得到充分研究。核因子红细胞2相关因子2（Nrf2）在抗氧化应激系统中起关键作用，该系统控制抗氧化反应元件（ARE）的驱动基因。激活Nrf2可抑制急性肝损伤和重症狼疮性肾炎中NLRP3炎性小体的激活。我们旨在探讨Nrf2通过Trx1/TXNIP复合物在脑缺血再灌注（脑I/R）损伤中抑制NLPR3炎性小体形成的保护作用。采用大脑中动脉闭塞/再灌注（MCAO/R）模型模拟缺血性损伤。通过腹腔注射叔丁基对苯二酚（tBHQ，16.7mg/kg）激活Nrf2，将Nrf2、Trx1和NLRP3的小干扰RNA（siRNA）注入左侧脑室（每只大鼠12μl），通过蛋白质免疫印迹法、实时定量聚合酶链反应（qRT-PCR）评估蛋白质和mRNA水平。采用酶联免疫吸附测定（ELISA）法检测白细胞介素-1β（IL-1β）和白细胞介素-18（IL-18）活性。上调Nrf2后，细胞质中TXNIP、NLRP3炎性小体及其下游因子半胱天冬酶-1、IL-18和IL-1β的表达显著降低，而敲低Nrf2则产生相反的结果。敲低Trx1产生与抑制Nrf2相同的效果，且Nrf2的保护作用大多被消除。我们的结果表明，Nrf2通过调节Trx1/TXNIP复合物作为NLRP3炎性小体激活的保护调节因子，这可能为缺血再灌注损伤的治疗提供新的见解。
