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.

中文翻译：

---

核苷酸结合域样受体蛋白 3 炎性体在早期脓毒症内皮功能障碍中的作用。

内皮功能障碍是导致多器官衰竭和脓毒症高死亡率的原因。核苷酸结合域样受体蛋白 3 (NLRP3) 炎性体在脓毒症的进展中起重要作用。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。本研究采用盲肠结扎穿刺（CLP）手术诱导脓毒症小鼠，用脂多糖（LPS）处理人脐静脉内皮细胞（HUVECs）。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。通过蛋白质印迹测定主动脉和 HUVEC 中 p-eNOS、eNOS、TLR4、MYD88、p-p65、p65、p-ikbα、ikbα、iNOS、NLRP3 和 IL-1β 的表达。我们的研究结果表明，CLP 后 p-eNOS 表达下调，内皮依赖性舒张功能受损，TLR4、MYD88、p-p65、p-ikbα、iNOS、NLRP3 和 IL-1β 表达增加。CLP术后12 h开始死亡，术后24 h病死率接近50%。在 CLP 小鼠中，NLRP3 特异性抑制剂 MCC950 干预或 NLRP3 敲除可显着改善 p-eNOS、内皮依赖性血管舒张功能和存活率的下降。当用 MCC950 或白细胞介素-1 受体拮抗剂 (IL-1Ra) 预处理时，LPS 诱导的 HUVEC 中 p-eNOS 的减少得到缓解。总之，我们的结果表明，NLRP3 炎性体的激活有助于小鼠早期脓毒症内皮功能障碍的发展，