Transgenic expression of replication-restricted enteroviral genomes in heart muscle induces defective excitation-contraction coupling and dilated cardiomyopathy.
Transgenic expression of replication-restricted enteroviral genomes in heart muscle induces defective excitation-contraction coupling and dilated cardiomyopathy.
复制标题
心肌中复制限制性肠道病毒基因组的转基因表达可诱导缺陷性兴奋-收缩耦合和扩张型心肌病。
DOI：
10.1172/jci1972
复制
发表时间：
1998
期刊：
影响因子：
--
通讯作者：
Knowlton,KU
中科院分区：
文献类型：
--
作者：
Wessely,R;Klingel,K;Santana,LF;Dalton,N;Hongo,M;JonathanLederer,W;Kandolf,R;Knowlton,KU
许多研究表明柯萨奇病毒与急性和慢性心力衰竭有关。虽然肠道病毒核酸已在选定的扩张型心肌病患者中检测到，但这种持续核酸的意义尚不清楚。为了研究柯萨奇病毒蛋白质低水平表达的限制性病毒复制可能能够诱导心肌病的机制，我们产生了在心肌细胞特异性肌球蛋白轻链-2v（MLC-2 v）启动子驱动下在心脏中表达复制限制性全长柯萨奇病毒B3（CVB 3）cDNA突变体（CVB 3 DeltaVP 0）的转基因小鼠。CVB 3DeltaVP 0是通过将感染性CVB 3cDNA在VP 4/VP 2自催化切割位点处由Asn-Ser突变为Lys-Ala而产生的。该cDNA的心脏特异性表达导致心脏中正链和负链病毒RNA的合成，而不形成感染性病毒后代。转基因心脏的组织学分析显示了心肌间质纤维化的典型形态学特征，在某些情况下，心肌细胞变性，因此类似于人类的扩张型心肌病。心室心房利钠因子mRNA水平也增加，表明心室肥大和衰竭的典型基因表达的胚胎程序激活。超声心动图分析表明，与野生型同窝小鼠相比，转基因小鼠存在左心室扩张和收缩功能降低，表现为心室舒张末期和收缩末期尺寸增加和缩短分数降低。从转基因小鼠分离的肌细胞的分析表明，有缺陷的兴奋-收缩偶联和减少的幅度孤立的细胞缩短。这些数据表明，肠道病毒基因组在心脏中的限制性复制可诱导扩张型心肌病，其兴奋-收缩偶联异常类似于扩张型心肌病的压力超负荷模型。
Numerous studies have implicated Coxsackievirus in acute and chronic heart failure. Although enteroviral nucleic acids have been detected in selected patients with dilated cardiomyopathy, the significance of such persistent nucleic acids is unknown. To investigate the mechanisms by which restricted viral replication with low level expression of Coxsackieviral proteins may be able to induce cardiomyopathy, we generated transgenic mice which express a replication-restricted full-length Coxsackievirus B3 (CVB3) cDNA mutant (CVB3DeltaVP0) in the heart driven by the cardiac myocyte-specific myosin light chain-2v (MLC-2v) promoter. CVB3DeltaVP0 was generated by mutating infectious CVB3 cDNA at the VP4/VP2 autocatalytic cleavage site from Asn-Ser to Lys-Ala. Cardiac-specific expression of this cDNA leads to synthesis of positive- and negative-strand viral RNA in the heart without formation of infectious viral progeny. Histopathologic analysis of transgenic hearts revealed typical morphologic features of myocardial interstitial fibrosis and in some cases degeneration of myocytes, thus resembling dilated cardiomyopathy in humans. There was also an increase in ventricular atrial natriuretic factor mRNA levels, demonstrating activation of the embryonic program of gene expression typical of ventricular hypertrophy and failure. Echocardiographic analysis demonstrated the presence of left ventricular dilation and decreased systolic function in the transgenic mice compared with wild-type littermates, evidenced by increased ventricular end-diastolic and end-systolic dimensions and decreased fractional shortening. Analysis of isolated myocytes from transgenic mice demonstrate that there is defective excitation-contraction coupling and a decrease in the magnitude of isolated cell shortening. These data demonstrate that restricted replication of enteroviral genomes in the heart can induce dilated cardiomyopathy with excitation-contraction coupling abnormalities similar to pressure overload models of dilated cardiomyopathy.