肝硬化患者外周血单核细胞内毒素受体表达与慢性炎症反应关系的临床意义

Clinical Significance of Expression of Endotoxin Receptors on Peripheral Blood Mononuclear Cells and its Relationship with Chronic Inflammatory Response Status in Patients with Liver Cirrhosis

背景:内毒素受体在内毒素、细胞因子等介导的炎性信号转导过程中具有重要作用。目的:了解肝硬化患者外周血单核细胞(PBMC)内毒素受体的表达变化与慢性炎症反应关系的临床意义。方法:应用荧光素标记的抗人Toll样受体(TLR)4/抗人CD14单抗,以流式细胞术检测40例肝硬化患者和15名健康志愿者PBMC内毒素受体TLR4和CD14蛋白的表达;以逆转录聚合酶链反应(RT-PCR)检测内毒素受体TLR4 mRNA、CD14 mRNA和信号转导分子MyD88 mRNA的表达;以酶联免疫吸附测定(ELISA)检测血清白细胞介素(IL)-1β、IL-10和肿瘤坏死因子(TNF)-α水平;以偶氮基质显色法测定血浆内毒素水平。结果:肝硬化患者PBMC内毒素受体TLR4和CD14蛋白的表达水平显著高于对照组(P<0.05),但不同Child-Pugh分级组间差异无统计学意义;与对照组相比,PBMC内毒素受体TLR4 mRNA、CD14 mRNA和信号转导分子MyD88 mRNA的表达水平也有增高的趋势,但差异无统计学意义(P>0.05);肝硬化患者血清细胞因子IL-1β、IL-10和TNF-α水平,以及血浆内毒素水平均较对照组显著升高(P<0.05),且高内毒素水平患者内毒素受体的表达显著高于低内毒素水平患者(P<0.05),细胞因子水平也较低内毒素水平者增高。结论:肝硬化患者PBMC内毒素受体的表达明显上调,与患者的慢性炎症反应状态一致。

Background： Endotoxin receptors play an important role in the endotoxin- and cytokine-mediated inflammatory signal transduction. Aims： To investigate the clinical significance of expression of endotoxin receptors on peripheral blood mononuclear cells （PBMC） and its relationship with chronic inflammatory response status in patients with liver cirrhosis. Methods： The protein expression of Toll-like receptor （TLR）4 and CD14 on PBMC was determined by flow cytometry with fluorescence labeled anti-TLR4/anti-CD14 monoclonal antibodies in 40 patients with liver cirrhosis and 15 healthy controls. The mRNA expression of endotoxin receptors TLR4, CD14 and signal transduction molecule MyD88 were determined by reverse transcriptase polymerase chain reaction （RT-PCR）. Enzyme-linked immunosorbent assay （ELISA） was used to measure the levels of serum interleukin （IL）-1β, IL-10 and tumor necrosis factor （TNF）-α. The plasma level of endotoxin was measured by limulus assay. Results： The protein expression of endotoxin receptors TLR4 and CD14 on PBMC was significantly higher in patients with liver cirrhosis than that in the healthy controls （P〈0.05）, but no significant difference was seen in different Child-Pugh grades. The mRNA expression of endotoxin, receptors TLR4, CD14 and signal transduction molecule MyD88 on PBMC also had a tendency to be higher in patients with liver cirrhosis, but the difference was not statistically significant （P〉0.05）. The serum levels of cytokines IL-1β, IL-10 and TNF-α and the plasma level of endotoxin were significantly higher in cirrhotic patients than those in the healthy controls （P〈0.05）. The expression of endotoxin receptors was significantly higher in patients with high endotoxin level than that in patients with low endotoxin level （P〈0.05）, the levels of cytokines were also higher. Conclusions： The expression of endotoxin receptors on PBMC was up-regulated significantly in patients with liver cirrhosis and is concordant with the status of chronic inflammatory response.