uPA-/-小鼠肝纤维化模型中的a-SMA、MMP13表达分析与模型评价

The Expression of a-SMA, MMP13 and Model Evaluation in uPA Knock-out （uPA-/-） Mice with Liver Fibrosis

目的采用uPA基因缺失（uPA-/-）小鼠构建肝纤维化动物模型，经a-平滑肌肌动蛋白（a-SMA）与金属基质蛋白酶-13（MMP13）的表达分析，评价其可行性。方法选取成年雄性BL／6J野生型和uPA-/-基因缺失型小鼠，分为4组：对照组（Con—WT，Con—uPA-/-）和模型组（Mod—WT，Mod—uPA-/-），每组20只。模型组小鼠腹腔注射10％CCl4，对照组小鼠腹腔注射橄榄油，每周2次，连续6周，诱导小鼠肝纤维化。用Real—time PCR方法检测小鼠肝脏组织中a—SMA和MMP13的mRNA表达，Western blot及免疫组化分析a-SMA和MMP13的蛋白表达。结果Real—time PCR结果显示，uPA乒小鼠的肝脏中a-SMA、MMP13的mRNA表达量显著高于M小鼠；Western blot结果显示，a-SMA蛋白和MMP13蛋白在对照组小鼠肝脏中几乎不表达，在Mod—WT中有少量表达，在Mod-uPA-／-中表达明显增多：免疫组化结果显示，Mod-uPA-／-的a-SMA和MMP13表达高于Mod-WT。结论a—SMA的mRNA和蛋白表达在uPA-／-小鼠中均明显升高，uPA基因的缺失促进了肝星型细胞向肌成纤维细胞的转化，从而加速了细胞外基质蛋白在肝脏中的沉积；MMP13蛋白表达在肝纤维化模型小鼠中均有明显升高。uPA基因缺失（uPA-/-）小鼠是建立肝纤维化模型的易感品系。

Objective To evaluate the feasibility of uPA knock-out （uPA-/-） mice liver fibrosis model by analysing the expression of a-Smooth Muscle Actin （a-SMA） and Matrix Metalloproteinase-13 （MMP13）. Methods Adult male C57BL/6J WT mice and uPA knock-out （uPA-/-） mice were divided into four groups with 10 mice in each group： control groups （Con-WT, Con- uPA-/-） and liver fibrosis model groups （Mod-WT, Mod-uPA-/-）. Mice were intraperitoneally injected with 0.15ml 10% CCl4 （or olive oil as control） twice per week for 6 weeks to induce liver fibrosis. The mRNA expression of a-SMA and MMP13 was detected by real-time polymerase chain reaction （PCR） and the protein expression of a-SMA and MMP13 was analyzed by western blot and immunohistochemistry. Result The real-time PCR showed that the mRNA expression of a-SMA, MMP13 in uPA-/- mice wes significantly higher than that in WT mice. The western blot results indicated that there were no expression of a-SMA protein and MMP13 protein of the mice liver in the control group, a few expression of a-SMA protein in Mod-WT group, and a significant increase of a-SMA protein expression in the Mod-uPA-/- group. The immunohis- tochemistry results demonstrated that the protein expression of a-SMA and MMP13 of Mod-uPA-/- group was higher than Mod-WT group. Conclusion The mRNA and protein expression of a-SMA were significantly higher in the uPA-/- mice. The knocking-out of the uPA gene promoted the hepatic stellate cells transforming into myofibroblasts, thus speeding up the deposition of extracellular matrixin in the liver. Also, the protein expression of MMP13 in liver fibrosis model mice was significantly increased. uPA-/- mice are susceptible animal strain to establish liver fibrosis model.