NLR家族pyrin结构域3(NLRP3)炎症小体的激活在防御感染中起重要作用。但是它的异常激活与许多炎症性疾病有因果关系,从而成为这些疾病的治疗靶点。Theaflavin,红茶的主要成分之一,具有有效的抗炎和抗氧化活性。在这项研究中,我们在体外和相关疾病的动物模型中研究了茶黄素对巨噬细胞中NLRP3炎性体活化的治疗作用。我们显示茶黄素(50、100、200μM)剂量依赖性地抑制ATP刺激的LPS引发的巨噬细胞中的NLRP3炎性体活化,尼日利亚霉素或尿酸单钠晶体(MSU),caspase-1p10和成熟的白介素-1β(IL-1β)的释放减少。茶黄素处理还抑制了焦亡,如gasderminD(GSDMD-NT)的N末端片段的产生减少和碘化丙啶的掺入所示。与这些一致,茶黄素治疗抑制了用ATP或尼日利亚素刺激的巨噬细胞的ASC斑点形成和寡聚化,提示炎症小体组装减少。我们发现茶黄素对NLRP3炎性体组装和焦亡的抑制是由线粒体功能障碍改善和线粒体ROS产生减少引起的。从而抑制ROS下游的NLRP3和NEK7之间的相互作用。此外,我们发现口服茶黄素可显著减轻MSU诱导的小鼠腹膜炎,提高细菌性败血症小鼠的存活率.始终如一,给予茶黄素可显著降低脓毒症小鼠血清炎症因子(包括IL-1β)水平,减轻肝脏炎症和肾脏损伤,伴随着肝脏和肾脏中caspase-1p10和GSDMD-NT的产生减少。一起,我们证明茶黄素通过保护线粒体功能抑制NLRP3炎性体激活和焦亡,从而减轻小鼠的急性痛风性腹膜炎和细菌性败血症,强调在治疗NLRP3炎性体相关疾病中的潜在应用。
Activation of NLR family pyrin domain-containing 3 (NLRP3) inflammasome plays important role in defending against infections, but its aberrant activation is causally linked to many inflammatory diseases, thus being a therapeutic target for these diseases. Theaflavin, one major ingredient of black tea, exhibits potent anti-inflammatory and anti-oxidative activities. In this study, we investigated the therapeutic effects of
theaflavin against NLRP3 inflammasome activation in macrophages in vitro and in animal models of related diseases. We showed that
theaflavin (50, 100, 200 μM) dose-dependently inhibited NLRP3 inflammasome activation in LPS-primed macrophages stimulated with ATP, nigericin or monosodium urate crystals (MSU), evidenced by reduced release of caspase-1p10 and mature interleukin-1β (IL-1β).
Theaflavin treatment also inhibited pyroptosis as shown by decreased generation of N-terminal fragment of gasdermin D (GSDMD-NT) and propidium iodide incorporation. Consistent with these, theaflavin treatment suppressed ASC speck formation and oligomerization in macrophages stimulated with ATP or nigericin, suggesting reduced inflammasome assembly. We revealed that
theaflavin-induced inhibition on NLRP3 inflammasome assembly and pyroptosis resulted from ameliorated mitochondrial dysfunction and reduced mitochondrial ROS production, thereby suppressing interaction between NLRP3 and NEK7 downstream of ROS. Moreover, we showed that oral administration of
theaflavin significantly attenuated MSU-induced mouse peritonitis and improved the survival of mice with bacterial sepsis. Consistently, theaflavin administration significantly reduced serum levels of inflammatory cytokines including IL-1β and attenuated liver inflammation and renal injury of mice with sepsis, concomitant with reduced generation of caspase-1p10 and GSDMD-NT in the liver and kidney. Together, we demonstrate that theaflavin suppresses NLRP3 inflammasome activation and pyroptosis by protecting mitochondrial function, thus mitigating acute gouty peritonitis and bacterial sepsis in mice, highlighting a potential application in treating NLRP3 inflammasome-related diseases.