Center on Translational Neuroscience, College of Life and Environmental Sciences, Minzu University of China, Beijing, 100081, China.
Brain Science Center, Beijing Institute of Basic Medical Sciences, Beijing, 100850, China.
Acta Pharmacol Sin. 2021 Nov;42(11):1769-1779. doi: 10.1038/s41401-021-00613-8. Epub 2021 Feb 24.
NOD-like receptor (NLR) family pyrin domain-containing-3 (NLRP3) inflammasome is implicated in inflammation-associated diseases such as multiple sclerosis, Parkinson's disease, and stroke. Targeting the NLRP3 inflammasome is beneficial to these diseases, but few NLRP3 inflammasome-selective inhibitors are identified to date. Essential oils (EOs) are liquid mixtures of volatile and low molecular-weight organic compounds extracted from aromatic plants, which show various pharmacological activities, including antibacterial, antifungal, antiviral, antioxidant, and anti-inflammatory properties. In this study we screened active ingredients from essential oils, and identified 1,2,4-trimethoxybenzene (1,2,4-TTB) as a selective NLRP3 inflammasome inhibitor. We showed that 1,2,4-TTB (1 mM) markedly suppressed nigericin- or ATP-induced NLRP3 inflammasome activation, thus decreased caspase-1 activation and IL-1β secretion in immortalized murine bone marrow-derived macrophages (iBMDMs) and in primary mouse microglia. Moreover, 1,2,4-TTB specifically inhibited the activation of NLRP3 inflammasome without affecting absent in melanoma 2 (AIM2) inflammasome activation. We further demonstrated that 1,2,4-TTB inhibited oligomerization of the apoptosis-associated speck-like protein containing a CARD (ASC) and protein-protein interaction between NLRP3 and ASC, thus blocking NLRP3 inflammasome assembly in iBMDMs and in primary mouse macrophages. In mice with experimental autoimmune encephalomyelitis (EAE), administration of 1,2,4-TTB (200 mg · kg · d, i.g. for 17 days) significantly ameliorated EAE progression and demyelination. In conclusion, our results demonstrate that 1,2,4-TTB is an NLRP3 inflammasome inhibitor and attenuates the clinical symptom and inflammation of EAE, suggesting that 1,2,4-TTB is a potential candidate compound for treating NLRP3 inflammasome-driven diseases, such as multiple sclerosis.
NOD 样受体 (NLR) 家族包含吡咯烷域的 3 (NLRP3) 炎性小体与多发性硬化症、帕金森病和中风等炎症相关疾病有关。针对 NLRP3 炎性小体对这些疾病有益，但迄今为止很少有 NLRP3 炎性小体选择性抑制剂被鉴定出来。精油 (EOs) 是从芳香植物中提取的挥发性和低分子量有机化合物的液体混合物，具有多种药理活性，包括抗菌、抗真菌、抗病毒、抗氧化和抗炎特性。在这项研究中，我们从精油中筛选出活性成分，并鉴定出 1,2,4-三甲氧基苯 (1,2,4-TTB) 为选择性 NLRP3 炎性小体抑制剂。我们表明，1,2,4-TTB(1mM) 显著抑制 Nigericin 或 ATP 诱导的 NLRP3 炎性小体激活，从而减少了永生化鼠骨髓来源的巨噬细胞 (iBMDMs) 和原代小鼠小胶质细胞中的 caspase-1 激活和 IL-1β 分泌。此外，1,2,4-TTB 特异性抑制 NLRP3 炎性小体的激活，而不影响黑色素瘤 2 (AIM2) 炎性小体的激活。我们进一步证明，1,2,4-TTB 抑制凋亡相关斑点样蛋白 (ASC) 的寡聚化和 NLRP3 与 ASC 之间的蛋白-蛋白相互作用，从而阻断 iBMDMs 和原代小鼠巨噬细胞中 NLRP3 炎性小体的组装。在实验性自身免疫性脑脊髓炎 (EAE) 小鼠中，1,2,4-TTB(200mg·kg·d，灌胃给药，共 17 天) 的给药显著改善了 EAE 的进展和脱髓鞘。总之，我们的结果表明，1,2,4-TTB 是一种 NLRP3 炎性小体抑制剂，可减轻 EAE 的临床症状和炎症，表明 1,2,4-TTB 是治疗 NLRP3 炎性小体驱动疾病的潜在候选化合物，例如多发性硬化症。
