State Key Laboratory of Toxicology and Medical Countermeasures, Institute of Pharmacology and Toxicology, Academy of Military Medical Sciences, No 27, Taiping Road, Haidian District, Beijing, 100850, China.
State Key Laboratory of Toxicology and Medical Countermeasures, Institute of Pharmacology and Toxicology, Academy of Military Medical Sciences, No 27, Taiping Road, Haidian District, Beijing, 100850, China.
Toxicology. 2020 Feb 28;432:152392. doi: 10.1016/j.tox.2020.152392. Epub 2020 Jan 31.
Acrylamide (AA) constitutes an important industrial chemical agent and well-known neurotoxin. However, the mechanism underlying AA-mediated neurotoxicity is extremely complicated and controversial. In this study, we found that activation of the NLR family pyrin domain containing 3 (NLRP3) inflammasome and its subsequent downstream inflammatory responses plays an important role in AA-induced neurotoxicity mechanisms. In vitro experiments revealed that AA (2.5 mM) induced BV2 microglial cytotoxicity and triggered NLRP3 inflammasome activation along with downstream proinflammatory cytokine interleukin-1β and interleukin-18 expression. Treatment with inhibitor or NLRP3 siRNA efficiently protected BV2 microglial cells against AA-induced cytotoxicity and reversed NLRP3 inflammasome activation and its mediated inflammatory reaction. Similarly, AA exposure (50 mg/kg) for 10 consecutive days caused significant activation of NLRP3 inflammasomes and neuroinflammation in C57BL/6 mice, whereas inhibiting these effects through specific NLRP3 inflammasome blocker MCC950 (5 mg/kg) intervention or NLRP3 knock-out significantly ameliorated AA-induced ataxia, cerebellar Purkinje cells degeneration, and apoptosis. Furthermore, we demonstrated that antagonism of NLRP3 could also up-regulate the Nrf2 signalling pathway and related antioxidant genes. In conclusion, our findings indicate that activation of the NLRP3 inflammasome pathway is involved in AA-induced neurotoxicity, whereas MCC950 treatment or NLRP3 knock-out could effectively protect against AA-induced neurotoxic injury through the inhibition of neuroinflammation and activation of the Nrf2 antioxidant pathway. Therefore, the NLRP3 inflammasome might serve as a promising therapeutic target, with drugs designed to specifically inhibit this pathway potentially providing new avenues for preventing or ameliorating AA poisoning.
丙烯酰胺（AA）是一种重要的工业化学试剂，也是一种知名的神经毒素。然而，AA 介导的神经毒性的机制极其复杂且存在争议。在本研究中，我们发现，NLR 家族 pyrin 结构域包含 3（NLRP3）炎性小体的激活及其随后的下游炎症反应在 AA 诱导的神经毒性机制中发挥着重要作用。体外实验表明，AA（2.5mM）诱导 BV2 小胶质细胞毒性，并触发 NLRP3 炎性小体激活以及下游促炎细胞因子白细胞介素-1β和白细胞介素-18 的表达。抑制剂或 NLRP3 siRNA 的处理可有效保护 BV2 小胶质细胞免受 AA 诱导的细胞毒性，并逆转 NLRP3 炎性小体的激活及其介导的炎症反应。同样，AA 暴露（50mg/kg）连续 10 天会导致 NLRP3 炎性小体在 C57BL/6 小鼠中的显著激活和神经炎症，而通过特异性 NLRP3 炎性小体阻断剂 MCC950（5mg/kg）干预或 NLRP3 敲除来抑制这些作用则显著改善了 AA 诱导的共济失调、小脑浦肯野细胞退化和细胞凋亡。此外，我们证明了 NLRP3 的拮抗作用还可以上调 Nrf2 信号通路和相关抗氧化基因。总之，我们的研究结果表明，NLRP3 炎性小体通路的激活参与了 AA 诱导的神经毒性，而 MCC950 治疗或 NLRP3 敲除通过抑制神经炎症和激活 Nrf2 抗氧化通路，可有效保护 AA 诱导的神经毒性损伤。因此，NLRP3 炎性小体可能成为一个有前途的治疗靶点，设计专门抑制该通路的药物可能为预防或改善 AA 中毒提供新途径。
