内皮素在原发性胆汁性肝硬化中作用的初步研究

Preliminary study on the role of endothelin in the pathogenesis of primary biliary cirrhosis

目的通过观察原发性胆汁性肝硬化（PBC）患者外周血清内皮素（ET）水平以及应用熊去氧胆酸（UDCA）治疗前后血清中ET的变化，并与肝功能指标进行相关性分析，寻找ET与PBC疾病进展的关系。通过ET作用于外周血单个核细胞（PBMC）引起其分泌的肿瘤坏死因子（TNF）-α及白细胞介素（IL）-6的变化，探讨ET在PBC发病机制中可能的作用。方法用酶联免疫吸附试验（EHSA）法测量PBC患者外周血清ET的浓度。用ET-1刺激患者PBMC，检测分泌细胞因子的变化。应用反转录-聚合酶链反应（RT-PCR）判断TNF-α基因表达的改变。结果24例PBC患者血清ET水平为（6．0±2．8）pg／ml，明显高于健康对照组的（2．3±3．4）pg／ml。UDCA治疗前患者ET水平为（7．5±1．6）pg/ml，治疗后为（6．2±2．7）pg／ml，在90％可信区间内具有统计学意义（P=0．084）。血清ET水平与患者的肝功能生化指标无明显相关性。ET-1刺激后PBC患者TNF-α的产生有明显增加（P〈0．05），IL-6无显著性改变。RT-PCR证实，ET-1刺激PBMC引起TNF—α mRNA的表达增加。结论PBC患者外周血清中ET浓度明显高于健康志愿者，且可在UDCA治疗后下降。ET-1作用于人PBMC可引起TNF-αmRNA表达上调，TNF-α分泌增加，进而可能激活前炎症因子的级联放大反应，导致PBC疾病的发生发展。

Objective Toidentify the relationship between the concentration of endothelin and the progression of primary biliary cirrhosis （PBC） by measuring the endothelins （ET） level of PBC patients as well as the PBC patients who were treated withUDCA. In addition, the role of ET on regulating TNF-α and IL-6 secretion of PBMC is explored. Methods The ET level in serum of 24 PBC patients was measured by ELISA. Then PBMCs were stimulated by ET and the concentration of TNF-α, IL-6 levels were measured by ELISA. cDNAs from all RNA extracted from the PBMCs were synthesized, and the expression level of TNF-α was detected by semi-quantitative RT-PCR. Results ET concentration in PBC patietns was significantly higher than healthy controls [ （6.0±2.8） vs（2.3±3.4） pg/ml, P〈0.05 ]. The level of ET was not related to other serum biochemical markers.. After UDCA treatment, the level of ET in PBC patients had decreased [（7.5±1.6） vs （6.2±2.7） pg/ml, P=0.084]. After ET-1 stimulation, the secretion of TNF-α by PBMCs in PBC patients increased significantly, and the secretion of IL-6 decreased, but without statistically significant difference. RT- PCR showed that the expression level of TNF-α mRNA increased significantly after ET-1 stimulation. Conclusion The level of ET in PBC serum is much higher than that of the healthy controls. UDCA treatment can decrease the level of ET in PBC patients. ET can increase the expression of TNF-α mRNA. The increased secretion of TNF-α further activates inflammatory cytokine cascade that plays an important role in the development of PBC.