alpha-1抗胰蛋白酶在Stanford A型主动脉夹层血管重构中的作用及分子机制的研究

Role of alpha-1 anti trypsin in vascular remodeling of Stanford A type aortic dissection and its molecular mechanism

目的:探究α-1抗胰蛋白酶在A型主动脉夹层发病和治疗中的作用与机制。方法:取2012年4月～2016年4月在我院行手术治疗的Stanford A型主动脉夹层患者8例、升主动脉瘤患者8例、正常组8例的资料信息,比较各组血管组织中AAT的蛋白和基因表达水平同时检测血清中AAT含量的变化。使用人原代血管内皮细胞验证AAT对于血管内皮细胞在胰酶刺激下发生细胞凋亡的保护作用,采用皮下缓释angⅡ和血管注射胰酶构建比格犬血管夹层模型,给予AAT治疗后检测Caspase家族蛋白及基因的表达水平。结果:使用RT-PCR及Western blot检测,发现在A型血管夹层患者和主动脉瘤及正常人血管组织中均有不同程度的AAT表达,其中在主动脉瘤患者中AAT表达水平较正常组显著升高(P<0. 05),在A型主动脉夹层患者中AAT表达较正常组显著下调(P<0. 05);在人原代血管内皮细胞中使用AAT预孵育12 h后原代在MMP-2/9压力的作用下,其组织表达的Caspase家族蛋白Caspase-3、Caspase-8较PBS预孵育组显著下调。在动物模型体内,AAT治疗能够显著下调Caspase家族蛋白的mRNA和蛋白水平(P<0. 05)。结论:AAT能够通过抑制Caspase家族蛋白的激活进而抑制血管内皮细胞的凋亡,最终保护血管组织,阻止其形成动脉夹层。

Objective:To explore the role and mechanism ofα-1antitrypsin in the pathogenesis and treatment of type A aortic dissection.Methods:From April2012to April2016,8patients with Stanford A aortic dissection,8patients with ascending aortic aneurysm and8patients with normal aortic aneurysm were selected.The protein and gene expression of AAT in blood vessels were compared and the changes of AAT in serum were also detected.The protective effect of AAT on apoptosis of Vascular Endothelial cells stimulated by trypsin by using Human Primary Vascular Endothelial cells,the model of vascular dissection in Beagle dogs was established by subcutaneous slow-release angⅡand injection of trypsin.The expression of Caspase family proteins and genes were detected after AAT treatment.Results:By detection of RT-PCR and Western blot found that the expression of AAT in vascular tissues of patients with type A dissection,aortic aneurysm and normal people were different,the expression of AAT in the patients with aortic aneurysm was significantly higher than that in the normal group(P<0.05).The expression of AAT in patients with type A aortic dissection was significantly lower than that in normal group(P<0.05).Human primary vascular endothelial cells were preincubated with AAT for12hours under the pressure of MMP-2/9,and the expression of Caspase family protein Caspase-3,Caspase-8in human primary vascular endothelial cells were significantly down-regulated,compared with the group that preincubated with PBS.In vivo,AAT treatment could significantly down-regulate the mRNA and protein levels of Caspase family proteins(P<0.05).Conclusion:AAT can inhibit the apoptosis of vascular endothelial cells by inhibiting the activation of Caspase family proteins,ultimately protect the vascular tissue and prevent the formation of artery dissection.