Pulmonary and Critical Care Medicine, Jinan People's Hospital, Jinan, Shandong, 271199, People's Republic of China.
Department of Emergency, Jinan Key Laboratory of Acute Lung Injury Prevention and Treatment, Jinan Clinical Research Center of Respiratory Medicine, Jinan Clinical Research Center of Critical Care Medicine, Jinan People's Hospital, Jinan, 271199, Shandong, People's Republic of China.
Immunol Res. 2023 Oct;71(5):687-697. doi: 10.1007/s12026-023-09379-z. Epub 2023 Apr 10.
This study aims to confirm whether apolipoprotein C3 (ApoC3) can regulate the inflammatory response and tissue damage in acute lung injury (ALI) and explore its regulatory pathway. ALI mouse model was established by intraperitoneal injection of lipopolysaccharide (LPS). ApoC3 levels were detected by real-time quantitative polymerase chain reaction, immunohistochemistry, and western blot assays. The levels of various inflammatory factors were detected by enzyme-linked immunosorbent assay and western blot analysis. Finally, the expression of toll-like receptor (TLR)/nuclear factor kappa B (NF-κB) signaling pathway-related protein [TLR2, myeloid differentiation primary response protein 88 (MyD88), IL-1 receptor-associated kinase 1 (IRAK1), NF-κB p65, and inhibitor of kappa B alpha (IκBα)], SLP adaptor and CSK interacting membrane protein (SCIMP), spleen tyrosine kinase (Syk), and phosphorylated (p)-Syk was detected by western blot analysis. ApoC3 was overexpressed in ALI mouse lung tissue and cell inflammation model. Silencing ApoC3 reduced inflammatory factors and alleviated lung tissue damage in ALI mice. Silencing ApoC3 reduced inflammatory factors and downregulated the expression of TLR2, MyD88, IRAK1, NF-κB p65, and increased IκBα expression in LPS-treated RAW264.7 cells. Moreover, co-transfection of si-TLR2 and shApoC3 further enhanced the inhibitory effects on the levels of inflammatory factors induced by silencing ApoC3. ApoC3 overexpression increased the levels of inflammatory factors and protein expression of SCIMP and p-Syk, while silencing TLR2 reversed the promotive effects of ApoC3 overexpression on above factors. In LPS-induced ALI mouse model and inflammatory cell model, downregulation of ApoC3 reduced inflammatory factors and relieved tissue damage. This process might be achieved through the TLR pathway.
本研究旨在确认载脂蛋白 C3（ApoC3）是否可以调节急性肺损伤（ALI）中的炎症反应和组织损伤，并探讨其调节途径。通过腹腔注射脂多糖（LPS）建立 ALI 小鼠模型。通过实时定量聚合酶链反应、免疫组织化学和蛋白质印迹法检测 ApoC3 水平。通过酶联免疫吸附试验和蛋白质印迹分析检测各种炎症因子的水平。最后，通过蛋白质印迹法检测 toll 样受体（TLR）/核因子 kappa B（NF-κB）信号通路相关蛋白[TLR2、髓样分化初级反应蛋白 88（MyD88）、IL-1 受体相关激酶 1（IRAK1）、NF-κB p65 和κB 抑制蛋白α（IκBα）]、衔接蛋白和 CSK 相互作用膜蛋白（SCIMP）、脾酪氨酸激酶（Syk）和磷酸化（p）-Syk 的表达。ApoC3 在 ALI 小鼠肺组织和细胞炎症模型中过表达。沉默 ApoC3 可减少 ALI 小鼠的炎症因子并减轻肺组织损伤。沉默 ApoC3 可减少炎症因子并下调 LPS 处理的 RAW264.7 细胞中 TLR2、MyD88、IRAK1、NF-κB p65 的表达，并增加 IκBα 的表达。此外，共转染 si-TLR2 和 shApoC3 进一步增强了对沉默 ApoC3 诱导的炎症因子水平的抑制作用。ApoC3 过表达增加了炎症因子和 SCIMP 及 p-Syk 的蛋白表达水平，而沉默 TLR2 逆转了 ApoC3 过表达对上述因子的促进作用。在 LPS 诱导的 ALI 小鼠模型和炎症细胞模型中，下调 ApoC3 可减少炎症因子并缓解组织损伤。这个过程可能是通过 TLR 途径实现的。
