肝门静脉海绵样变性模型大鼠组织抑制因子及基质金属蛋白酶表达与周围血管新生

Expression of matrix metalloproteinases and tissue inhibitors of metalloproteinase in rats with cavernous transformation of portal vein and their role in peripheral angiogenesis

背景:目前国内外尚无有效治疗肝门静脉海绵样变性的策略,且其病因的基础研究报道较为鲜见。目的:拟建立大鼠门静脉海绵样变性模型,检测基质金属蛋白酶2,9,基质金属蛋白酶组织抑制剂1,2在大鼠门静脉及其周围组织的表达及周围血管新生中的作用。方法:SD大鼠80只随机分为3组。以门静脉部分缩窄法复制门静脉海绵样变性的大鼠模型,以21 G钝针头操作。模型组和假手术组分别设术后2,4,6周3个时间点,对照组即不做任何处理的正常SD大鼠(造影后取材)。各组分别于处理后不同时间点行门静脉造影,免疫组织化学检测血管内皮细胞标记物CD31观察门静脉周围血管变化,并使用实时荧光定量PCR和免疫组织化学法检测大鼠门静脉及其周围组织的基质金属蛋白酶2,9,基质金属蛋白酶组织抑制剂1,2 mR NA的含量和蛋白的表达。结果与结论:门静脉造影及血管内皮细胞标记物CD31免疫组织化学显示,模型组门静脉周围新生血管明显增多。RT-PCR与免疫组织化学结果分析显示:对照组和假手术组基质金属蛋白酶2 mR NA及蛋白表达均较同期模型组低(P<0.01,P<0.05),基质金属蛋白酶9 mR NA及蛋白表达均较同期模型组低。模型组基质金属蛋白酶组织抑制剂1,2各个时间段的表达水平与对照组和假手术组相比差异无显著性意义(P>0.05);模型组造模后第2周基质金属蛋白酶2/基质金属蛋白酶组织抑制剂2比值明显高于对照组和假手术组同期(P<0.05)。结果提示,构建的门静脉海绵样变性的模型大鼠死亡率低,成模率高,且比较稳定。基质金属蛋白酶2,9表达升高以及基质金属蛋白酶2/基质金属蛋白酶组织抑制剂2的比值失衡,可能是大鼠门静脉海绵样变周围血管新生的分子机制之一。

BACKGROUND：At present, there is no effective treatment strategy for cavernous transformation of portal vein and basic research about its etiology is rarely reported. OBJECTIVE：To establish the models of cavernous transformation of portal vein, detect the expression of matrix metal oproteinase-2,-9 （MMP-2, MMP-9） and tissue inhibitors 1, 2 of metal oproteinase （TIMP-1, TIMP-2） in rat portal vein and peripheral tissue, and discuss the roles in the process of peripheral angiogenesis. METHODS：Eighty Sprague-Dawley rats were randomly divided into three groups. The rat models of cavernous transformation of portal vein were established with partial coarctation in portal vein by using 21 G blunt pinhead.＆nbsp;Control group was normal rats without operation （samples were harvested after portal vein radiography）. Model group and sham operation group were divided into three groups respectively according to different time points, namely 2, 4 and 6 weeks after operation. Rats of each group were randomly chosen at week 2, 4 and 6 after operation to observe the formation of col ateral circulation of portal vein and its peripheral tissues by performing portal vein radiography. CD31 was detected by immunohistochemistry. The expression of MMP-2, MMP-9, TIMP-1, TIMP-2 mRNA and protein in portal vein and peripheral tissue were determined by RT-PCR and immunohistochemistry respectively. RESULTS AND CONCLUSION：Peripheral angiogenesis of model group was increased obviously by portal vein radiography and immunohistochemistry. RT-PCR and immunohistochemistry results demonstrated that, compared with the control group and sham operation group, the expression of MMP-2 mRNA and protein in model group were significantly increased at weeks 2, 4, and 6 （P0.05）. Ratio of MMP-2/TIMP-2 of model group was significantly higher than that of control group and sham operation group （P〈0.05） at week 2. the rat models of cavernous transformation of portal vein have low mortality, high success rate and are stable. Upregulation of the expression of MMP-2, MMP-9 and the disbanlance of the ratio of MMP-2/TIMP-2 might contribute to the peripheral angiogenesis in rats with cavernous transformation of portal vein.