心肌组织特异性表达质粒的构建及表达

Construction and Expression of Myocardium Specific Expression Vector

应用ＰＣＲ方法从大鼠基因组ＤＮＡ中扩增出心肌组织特异性顺式作用元件──心肌肌钙蛋白Ｃ（ＣａｒｄｉａｃＴｒｏｐｏｎｉｎＣ，ｃＴｎＣ）增强子／启动子序列，构建成ｃＴｎＣ启动子驱动ＬａｃＺ基因的真核表达质粒ｐｃＴｎＣβ。ＩｎＶｉｔｒｏ和ＩｎＶｉｖｏ试验证明该调控元件能驱动外源性基因在心肌细胞中特异性表达。

In vivo,the expression of the rat cardiac troponin C gene is restricted to slow-twitched skeletal muscleand myocardiun,Its promoter cTnC , position -134～+67,was amplified by PCR.The expressionplasmid pcTnC βin which the expression of LacZ gene was driven by cTnC promoter was constructed. Utilizing lipofectin to transfer the plasmid into cultured rat vascular smooth muscle cells(VSMCs)andcardiac myocyte or directly injecting it into rat quadriceps muscls and left ven tricular wall,the expressionofβ-galactosidase was detected only in cardiac myocytes but not in VSMCs and skeletal muscle.The resultindicated that a gene driven by the promoter cTnC can specifically express in cardiac myocytes.