p38MAPK信号转导途径对早期缺血再灌注期间离体肝脏ICAM1 mRNA表达的影响

Effect of p38MAPK Pathway on ICAM1 mRNA Expression of Isolated Rabbit Liver Tissue during Early Stage of Cold Preservation and Reperfusion Period

目的:研究离体肝脏缺血再灌注期间丝裂原活化蛋白激酶(mitogen activated protein kinase,p38MAPK)信号转导途径对细胞间黏附分子1(intercellular adhesion molecular 1,ICAM1)mRNA表达的影响。方法:建立兔离体肝脏缺血再灌注模型,对照组(n=12):灌注液中不加特异性p38MAPK抑制剂SB202190,抑制组(n=12):灌注液中加入SB202190(浓度为3μmol/L)。于肝脏离体前,冷保存末,再灌注10 min、30 min、60 min及120 min时获取离体肝组织标本。分别应用Western-blot法及免疫沉淀法检测离体肝组织中p38MAPK表达的水平及活性,原位杂交法检测ICAM1 mRNA表达水平。结果:与离体前相较,对照组p38MAPK活性在冷保存末及再灌注10 min、30 min、60 min显著性增高(P<0.01),而再灌注120 min时活性与离体前相较无明显差异(P>0.05);抑制组p38MAPK活性在各时相点的变化无显著性差异(P>0.05),除离体前及再灌注120 min两组肝脏的p38MAPK活性无显著性差异外,其余各时相点p38MAPK活性均显著性低于对照组(P<0.01)。离体前、冷保存末及再灌注10 min及30 min时,两组肝组织中仅有少量ICAM1 mRNA表达,组间及组内比较无显著性差异(P>0.05);至再灌注60 min及120 min,对照组ICAM1 mRNA的表达水平显著性高于组内其它时相点(P<0.01),而抑制组虽然也显著高于组内其它时相点(P<0.05),但却显著性低于同时相点对照组的表达水平(P<0.01)。离体再灌注期间供肝组织中p38MAPK活性与供肝组织内ICAM1 mRNA的表达水平呈显著性正相关(r=0.985,P<0.01)。结论:p38MAPK对ICAM1生成的调节作用层次可能在转录水平,提示p38MAPK信号转导途径对ICAM1 mRNA的调节可能是导致离体肝脏缺血再灌注损伤的重要机制之一。

Objective：To study the effect of p38MAPK activity on intercellular adhesion molecular 1（ICAM1） mRNA expression in isolated rabbit liver during early stage of cold preservation and reperfusion period.Methods：Based on the cold preservation reperfusion model of isolated rabbit liver,the isolated livers were divided into 2 groups：Group A treated without SB202190 and Group B treated with SB202190（3 μmol/L）.Liver tissue samples were harvested before cold preservation,at the end of cold preservation,and 10 min,30 min,60 min,120 min after reperfusion period.The activity of p38MAPK was detected by Western blot/immunoprecipitation and ICAM1 mRNA expression was detected by in situ hybridization.Results：At the end of cold preservation,10 min,30 min and 60 min after reperfusion,the activity of p38MAPK in Group A was significantly higher than that before harvest and 120 min after reperfusion（P〈0.01）,the activity of p38MAPK before harvest and 120 min after reperfusion had no significant difference;In Group B,there was no significant difference of p38MAPK activity among all time points（P〉0.05）,and also significantly lower than that in Group A at the same time points except before harvest and 120 min after reperfusion（P〈0.01）.Compared with 60 min and 120 min after reperfusion,the ICAM1 mRNA was significantly low expressed before cold preservation,at the end of cold preservation,and 10 min and 30 min after reperfusion in both groups（P〈0.05,P〈0.01）.The expression of ICAM1 mRNA in Group B were significantly lower than Group A 60 min and 120 min after reperfusion（P〈0.01）.The activity of p38MAPK of isolated liver tissue during cold preservation and reperfusion period was significantly positive correlated with expression intensity of ICAM1 mRNA（r=0.985,P〈0.01）.Conclusion：p38MAPK pathway may regulate the expression of ICAM1 at the level of transcription and the activation of p38MAPK can up-regulate ICAM1 expression.This may be one of the important mechanisms to cause ischemia-reperfusion injury of isolated liver during cold preservation and reperfusion period.