Department of Cardiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China.
Institute of Life Science, Chongqing Medical University, Chongqing, 400016, China.
Inflammation. 2020 Aug;43(4):1561-1571. doi: 10.1007/s10753-020-01232-x.
Endothelial dysfunction is responsible for multiple organ failure and the high mortality rate of sepsis. Nucleotide-binding domain-like receptor protein 3 (NLRP3) inflammasome plays an essential role in the progression of sepsis. However, the role of NLRP3 inflammasome in the endothelial dysfunction of sepsis has not been fully elucidated. In this study, septic mice were induced by cecal ligation and puncture (CLP) operation, and human umbilical vein endothelial cells (HUVECs) were treated with lipopolysaccharide (LPS). The 24-h survival rate after CLP was observed. Vasodilation function of the aorta was detected by vascular reactivity experiments. Expression of p-eNOS, eNOS, TLR4, MYD88, p-p65, p65, p-ikbα, ikbα, iNOS, NLRP3, and IL-1β in the aorta and HUVECs were determined by Western blot. Our results suggest that the p-eNOS expression was downregulated, the endothelium-dependent relaxation function was impaired, and TLR4, MYD88, p-p65, p-ikbα, iNOS, NLRP3, and IL-1β expression increased after CLP. The onset of death was 12 h after CLP, and the mortality rate was nearly 50% at 24 h after operation. The decline of p-eNOS, endothelium-dependent vasodilation function, and survival rate significantly improved with NLRP3-specific inhibitor MCC950 intervention or NLRP3 knockout in CLP mice. The decrease of p-eNOS in HUVECs induced by LPS was alleviated when pretreated with MCC950 or interleukin-1 receptor antagonist (IL-1Ra). In summary, our results indicate that activation of the NLRP3 inflammasome contributes to the development of endothelial dysfunction of early sepsis in mice, suggesting its potential role as a therapeutic target for the treatment of sepsis.
内皮功能障碍是多器官衰竭和脓毒症高死亡率的原因。核苷酸结合寡聚化结构域样受体蛋白 3（NLRP3）炎症小体在脓毒症的进展中起着至关重要的作用。然而，NLRP3 炎症小体在脓毒症内皮功能障碍中的作用尚未完全阐明。在本研究中，通过盲肠结扎穿孔（CLP）手术诱导脓毒症小鼠，并使用脂多糖（LPS）处理人脐静脉内皮细胞（HUVEC）。观察 CLP 后 24 小时的存活率。通过血管反应性实验检测主动脉的血管舒张功能。通过 Western blot 检测主动脉和 HUVEC 中 p-eNOS、eNOS、TLR4、MYD88、p-p65、p65、p-ikbα、ikbα、iNOS、NLRP3 和 IL-1β 的表达。结果表明，CLP 后 p-eNOS 表达下调，内皮依赖性松弛功能受损，TLR4、MYD88、p-p65、p-ikbα、iNOS、NLRP3 和 IL-1β 表达增加。CLP 后 12 小时出现死亡，术后 24 小时死亡率接近 50%。CLP 小鼠中 NLRP3 特异性抑制剂 MCC950 干预或 NLRP3 敲除可显著改善 p-eNOS、内皮依赖性血管舒张功能和存活率的下降。用 MCC950 或白细胞介素 1 受体拮抗剂（IL-1Ra）预处理可减轻 LPS 诱导的 HUVEC 中 p-eNOS 的减少。综上所述，我们的研究结果表明，NLRP3 炎症小体的激活有助于促进小鼠早期脓毒症内皮功能障碍的发展，提示其作为治疗脓毒症的潜在治疗靶点。
