胆道闭锁肝内iNOS及其调控因子异常表达与进行性肝损伤的相关性

目的 研究胆道闭锁(BA)患儿肝内诱导型一氧化氮合酶(iNOS)及其上下游调控因子表达情况,并探讨其与BA进行性肝损伤发生的关系.方法 应用免疫组织化学染色法对2002年10月至2007年3月在本院行Kasai手术的38例BA患儿与16例对照儿童肝组织iNOS表达情况进行研究;应用ELASA法对BA患儿和对照组外周血总一氧化氮(NO)代谢产物浓度进行测定;应用TUNEL法对BA患儿和对照组肝内胆管上皮凋亡指数进行测定;应用免疫印记法对BA患儿和对照组肝组织NF-κB表达进行半定量分析.结果 iNOS在BA患儿肝组织异常高表达,强度为0.30±0.08,而在对照组肝组织不表达.BA患儿外周血总NO代谢产物浓度为(90.40±12.46)mol/L,明显高于对照组的(63.67±5.78)μmol/L,且BA组总NO代谢产物浓度与血清ALT水平(152.76±29.59)U/L]呈强正相关(r=0.97).BA组肝内胆管上皮凋亡指数(54.00±11.67)%远高于正常对照组(20.72±5.63)%,且与肝组织iNOS表达强度呈强正相关(r=0.99).NF-κB出在BA患儿肝组织中的表达(0.74±0.06)明显高于正常对照组(0.22±0.03),且与iNOS表达强度呈强正相关(r=0.97).结论 iNOS异常高表达在BA患儿进行性肝损伤中发挥重要作用,该作用是由iNOS及其上下游调控因子NF-κB、NO共同作用所实现.

Abnormal expressions of iNOS and its regulatory factor in the liver of biliary atresia with progressive damage

Objective To study the expression of induced nitric oxide synthase(iNOS)and its up-down stream regulatory factors in the liver of biliary atresia(BA)with progressive hepatic damage.Methods The iNOS expressions in the liver of 38 cases of BA(mean age 94.5±41.5 d)from Oct 2002 to Mar 2007 and 16 cases(mean age 103.1±49.1 d)without hepatic or biliary disease selected as normal control were examined by immunohistochemistry staining method respectively.The total serum NO metabolites was evaluated by ELISA method;the apoptosis index of bile duct epithelial cells was analyzed by TUNEL method and the nuclear factor-κB(NF-κB)expression was assessed by western blotting with semi-quantitatively method.Results iNOS expression in hepatic tissues of BA was abnormal with average intensity of 0.30±0.08,and no expression in the normal control.The BA group had significantly higher levels of total serum NO metabolites(90.40±12.46 μmol/L)than the normal control(63.67±5.78 μmol/L).A positive correlation was detected between the concentration of NO metabolites and the serum ALT level(152.76±29.59 U/L)in BA group(r=0.97).The TUNEL-labeled apoptosis index in the epithelial cells of bile duct of BA group(54.00±11.67%)was significantly higher than that of the normal control(20.72±5.63%),and a positive correlation was demonstrated between the apoptosis index and the intensity of iNOS in BA group(r=0.99).The intensity of NF-κB expression in BA group(0.74±0.06)was much higher than that of the normal control(0.22±0.03)with a positive correlation(r=0.97).Conclusions The abnormal expression of iNOS might play a key role in the progressive hepatic damage of BA.It is controlled by iNOS and the up-down stream regulatory factors of NF-κB and NO.