1College of Traditional Chinese Veterinary Medicine, Agricultural University of Hebei, Baoding, China.
2Hebei Provincial Engineering Center for Traditional Chinese Veterinary Medicine, Baoding, China.
J Interferon Cytokine Res. 2019 Aug;39(8):495-505. doi: 10.1089/jir.2018.0137. Epub 2019 May 10.
The study was conducted to investigate the protective effects of polysaccharides (SMPs) on lipopolysaccharides (LPS)/d-galactosamine (d-GalN)-induced liver injury in mice and its mechanism. Seventy-two mice were allocated to 6 groups of 12 each, that is, the untreated control group, the liver injury model group, the Bifendate group (Bifendate 200 mg/kg/day), and 3 SMP-treated groups at low (250 mg/kg/day), medium (500 mg/kg/day), and high doses (750 mg/kg/day). After 12 days oral treatment, liver injury was induced with LPS/d-GalN, and 1 h later the mice were sacrificed for a series of analyses. The results showed that SMPs significantly alleviated pathological changes in the hepatic tissue. Compared with the untreated control group, the messenger RNA (mRNA) levels of lipopolysaccharide-binding protein (LBP), cluster of differentiation 14 (CD14), myeloid differentiation factor 2 (MD-2), toll-like receptor 4 (TLR4), and myeloid differentiation primary response protein 88 (MyD88) detected by quantitative real-time polymerase chain reaction (qRT-PCR), the protein levels of TLR4, MyD88, phosphorylated inhibitor of nuclear factor kappa-B kinase alpha/beta (P-IKK-α/β), phosphorylated inhibitor of NF-κB alpha (P-IκB-α) and phosphorylated P65 (P-P65) detected by Western blot, the levels of C-X-C motif chemokine 10 (CXCL-10) and Intercellular Adhesion Molecule 1 (ICAM-1) detected by immunohistochemistry, and the concentrations of tumor necrosis factor alpha (TNF-α) and interleukin 1 beta (IL-1β) detected by enzyme-linked immunosorbent assay of liver injury model group were increased significantly ( < 0.01). Compared with liver injury model group, the mRNA levels of LBP, CD14, MD-2, TLR4, and MyD88; protein levels of TLR4, MyD88, P-IKK-α/β, P-IκB-α, and P-P65; levels of CXCL-10 and ICAM-1; and the concentrations of TNF-α and IL-1β of SMP groups and Bifendate group were decreased significantly ( < 0.01 or < 0.05). In conclusion, SMPs can effectively inhibit TLR4/MyD88 inflammatory signaling pathway of LPS/d-GalN-induced liver injury in mice, and it may be part of the mechanism by which SMPs relieve excessive inflammation in the liver of mice.
本研究旨在探讨多糖（SMPs）对脂多糖（LPS）/D-半乳糖胺（D-GalN）诱导的小鼠肝损伤的保护作用及其机制。将 72 只小鼠随机分为 6 组，每组 12 只，即未处理对照组、肝损伤模型组、双环醇组（200mg/kg/天）和 3 个 SMP 处理组（低剂量 250mg/kg/天、中剂量 500mg/kg/天和高剂量 750mg/kg/天）。经 12 天口服给药后，用 LPS/D-GalN 诱导肝损伤，1 小时后处死小鼠进行一系列分析。结果表明，SMPs 可显著减轻肝组织的病理变化。与未处理对照组相比，LPS/D-GalN 诱导的肝损伤模型组中，脂多糖结合蛋白（LBP）、分化簇 14（CD14）、髓样分化因子 2（MD-2）、Toll 样受体 4（TLR4）和髓样分化初级反应蛋白 88（MyD88）的信使 RNA（mRNA）水平，Western blot 检测的 TLR4、MyD88、磷酸化核因子 kappa-B 激酶 alpha/beta（P-IKK-α/β）、磷酸化核因子 kappa-B alpha（P-IκB-α）和磷酸化 P65（P-P65）蛋白水平，免疫组化检测的 C-X-C 基序趋化因子 10（CXCL-10）和细胞间黏附分子 1（ICAM-1）水平，以及酶联免疫吸附试验检测的肿瘤坏死因子 alpha（TNF-α）和白细胞介素 1 beta（IL-1β）浓度均显著升高（<0.01）。与肝损伤模型组相比，SMP 组和双环醇组 LBP、CD14、MD-2、TLR4 和 MyD88 的 mRNA 水平；TLR4、MyD88、P-IKK-α/β、P-IκB-α 和 P-P65 的蛋白水平；CXCL-10 和 ICAM-1 的水平；以及 TNF-α 和 IL-1β 的浓度均显著降低（<0.01 或 <0.05）。综上所述，SMPs 可有效抑制 LPS/D-GalN 诱导的小鼠肝损伤中 TLR4/MyD88 炎症信号通路，这可能是 SMPs 缓解小鼠肝脏过度炎症的部分机制。
