急性肺损伤大鼠肺组织基质金属蛋白酶2及其抑制因子蛋白和mRNA的表达

目的探讨内毒素致急性肺损伤（ALI）大鼠肺组织核转录因子-κB（NF-κB）、基质金属蛋白酶2（MMP-2）及其抑制因子（TIMP-2）蛋白和mRNA表达的变化。方法 20只雄性Wistar大鼠随机分为2组：对照组、LPS模型组,每组再分为4 h和8 h两个亚组。尾静脉注射脂多糖（LPS）（10 mg/kg）建立大鼠急性肺损伤模型。检测血白细胞计数、支气管肺泡灌洗液（BALF）蛋白含量,采用免疫组化ABC法和实时荧光定量PCR分别测定肺组织NF-κB、MMP-2、TIMP-2蛋白及其mRNA的表达,并观察肺组织病理变化。结果与对照组相比,模型组4 h和8 h时大鼠肺组织中的NF-κB、MMP-2蛋白染色阳性面积率及其mRNA表达均显著增高（P〈0.01）、TIMP-2蛋白染色阳性面积率及其mRNA表达均明显降低（P〈0.05或P〈0.01）。病理学观察显示,模型组大鼠肺组织出现出血及坏死。结论内毒素致急性肺损伤的发病机制可能与NF-κB、MMP-2蛋白及其mRNA表达升高、TIMP-2蛋白及其mRNA表达降低有关。

Expression of the MMP-2 and TIMP-2 Protein and Its mRNA in Rats with Acute Lung Injury Caused by Lipopolysaccharide

Objective To investigate the changes of NF-κB,MMP-2 and TIMP-2 protein and its mRNA in the rats with acute lung injury（ALI） caused by lipopolysaccharide（LPS）.Methods Twenty male Wistar rats were randomly divided into two groups： normal control group,LPS model group.Each group had two subgroups,4 hours and 8 hours after LPS were injected.The ALI model was established by intravenous injection of LPS（10 mg /kg）through a tailvein.Then the white blood cell（WBC） in blood and the protein content in bronchial alveolar lavage fluid（BALF） were measured,the expressions of nuclear factor-κB（NF-κB）,matrix metalloproteinase-2（MMP-2） and tissue inhibitor of matrix metalloproteinases（TIMP-2） protein in pulmonary tissues were measured by immunohistochemistry ABC,the expression NF-κB,MMP-2 and TIMP-2mRNA were measured by real-time fluorescent polymerase chain reaction（PCR）,while the histopathology of the lung injury was observed by light microscope.Results Compared with normal group,the expression