核转录因子-κB诱导肿瘤坏死因子-α在肝肺综合征大鼠肺血管内巨噬细胞中的表达及吡咯醛二硫氨基甲酸对其表达的影响

目的 探讨核转录因子-κB(NF-κB)及肿瘤坏死因子-α(TNF-α)在大鼠肺血管内巨噬细胞(PIM)内的表达及吡咯醛二硫氨基甲酸(PDTC)对其表达的影响.方法 SD大鼠随机分4组:对照组、PDTC对照组、CCI4组、CCI4+PDTC组.取动脉血作血气分析,静脉血测内毒素和肝功能.取肠系膜淋巴结作细菌培养.应用免疫组化方法 观察PIM的粘附、聚集情况,以及TNF-α和NF-κB的蛋白表达和定位.非放射性凝胶电泳阻滞实验(EMSA)检测NF-κB活性,SYBR Green I实时定量PCR方法 检测肺组织中TNF-α的mRNA表达.结果 CCl4组发展成肝肺综合征(HPS)模型,表现为PaO2、PaCO2降低和肺泡一动脉血氧分压(A-aDO2)升高,肝功能异常,内毒素血症.CCl4组肠系膜淋巴结培养阳性率为62.5%(5/8),与CCl4+PDTC组的66.7%(6/9)比较差异无统计学意义(P>0.05).CCl4组超过10个巨噬细胞的血管为60.8%(292/480),而CCl4+PDTC组仅为19.6%(106/540),两组比较差异有统计学意义(P<0.01).对照组和PDTC对照组中肺血管内无巨噬细胞聚集.免疫组化染色NF-κB和TNF-α蛋白均在CCl4组的PIM中表达.CCl4组的NF-κB活性和TNF-α的mRNA表达明显高于对照组、PDTC对照组和CCl4+PDTC组(均P<0.05).结论 NF-κB诱导PIM内TNF-α表达在HPS中发挥重要作用,PDTC通过抑制PIM中NF-κB的活性,降低PIM活性以及其中TNF-α表达,从而改善HPS.

TNF-α expression induced by NF-κB in pulmonary intravascular macrophages of rats with hepatopulmo-nary syndrome and the effect of pyrrolidine dithiocarbamate on the expression

Objective To study the expression of both nuclear factor-κB(NF-κB)and tumor necrosis fac-tor-α(TNF-α)in pulmonary intravascular macrophages(PIM)of rats with hepatopulmonary syndrome (HPS)and the effect of pyrrolidine dithiocarbamate(PDTC)on their expression.Methods The Sprague-Dawley(SD)rats were randomly divided into four groups:control,control+PDTC1CCl4,CCl4+PDTC groups.Arterial blood was collected for measurement of blood gas.Venous blood was sampled for hepatic function and endotoxin level.The mesenteric lymph nodes were dissected for bacteriology studies.Proteins of NF-κB and TNF-a of lung tissue were examined by immunohistochemistry.The activity of NF-κB in lung tissues was measured using electrophoretic mobility shift assay (EMSA).By real-time polymerase chain reaction (PCB)using SYBR Green I,the mRNA expression of TNF-α in lung tissues were detected.Results CCl4 group developed HPS with decreased PaO2 and PaCO2,increased alveolar-arterial oxygen difference(A-aDO2),abnormal hepatic function and increased endotoxin level.Culture-positive mes-enteric lymph nodes were found in 62.5%(5/8)of CCl4,group and 66.7%(6/9)of CCl4+PDTC group(P>0.05 J.All lungs from CCl4 and CCl4+PDTC group showed no accumulation of larse mononuclear macrophagelike cells within the lumen of numerous small muscular and nonnulscular pulmonary vessels.The percentages of vessels with more than 1O adherent macrophages was 60.8%(292/480)in CCl4 group but only 19.6%(106/540)in CCl4+PDTC group(P<0.01).The protein expression of NF-κB and TNF-α Was localized to PIM in CCl4 group.The NF-κB activity and mRNA expression of TNF-α in CCl4 group was significantly higher than that in control,con-trol+PDTC group and CCl4+PDTC group(P<0.05).Conclusion The TNF-α expression in PIM induced by NF-κB play an important role in HPS.The inhibitor of NF-κB PDTC can repress PIM activation and decrease the ex-pression of TNF-α.As result.HPS severity is reduced.