Abstract：
BACKGROUND: Gene therapy has been proposed as a strategy to induce cardiac regeneration following acute myocardial infarction (AMI). Given that Tbx20, a transcription factor of the T-box subfamily, stimulates cell proliferation and angiogenesis, we designed a baculovirus overexpressing Tbx20 (Bv-Tbx20) and evaluated its effects in cultured cardiomyocytes and in an ovine model of AMI.
RESULTS: Cell proliferation and angiogenesis were measured in cardiomyocytes transduced with Bv-Tbx20 or Bv-Null (control). Subsequently, in sheep with AMI, Bv-Tbx20 or Bv-Null was injected in the infarct border. Cardiomyocyte cell cycle activity, angioarteriogenesis, left ventricular function, and infarct size were assessed. Cardiomyocytes transduced with BvTbx20 increased cell proliferation, cell cycle regulatory and angiogenic gene expression, and tubulogenesis. At 7 days posttreatment, sheep treated with Bv-Tbx20 showed increased Tbx20, promitotic and angiogenic gene expression, decreased levels of P21, increased Ki67- (17.09±5.73 versus 7.77±7.24 cardiomyocytes/mm2, P<0.05) and PHH3 (phospho-histone H3)-labeled cardiomyocytes (10.10±3.51 versus 5.23±2.87 cardiomyocytes/mm2, P<0.05), and increased capillary (2302.68±353.58 versus 1694.52±211.36 capillaries/mm2, P<0.001) and arteriolar (146.95±53.14 versus 84.06±16.84 arterioles/mm2, P<0.05) densities. At 30 days, Bv-Tbx20 decreased infarct size (9.89±1.92% versus 12.62±1.33%, P<0.05) and slightly improved left ventricular function. Baculoviral gene transfer-mediated Tbx20 overexpression exerted angiogenic and cardiomyogenic effects in vitro.
CONCLUSIONS: In sheep with AMI, Bv-Tbx20 induced angioarteriogenesis, cardiomyocyte cell cycle activity, infarct size limitation, and a slight recovery of left ventricular function, suggesting that Bv-Tbx20 gene therapy may contribute to cardiac regeneration following AMI.
RESULTS: Cell proliferation and angiogenesis were measured in cardiomyocytes transduced with Bv-Tbx20 or Bv-Null (control). Subsequently, in sheep with AMI, Bv-Tbx20 or Bv-Null was injected in the infarct border. Cardiomyocyte cell cycle activity, angioarteriogenesis, left ventricular function, and infarct size were assessed. Cardiomyocytes transduced with BvTbx20 increased cell proliferation, cell cycle regulatory and angiogenic gene expression, and tubulogenesis. At 7 days posttreatment, sheep treated with Bv-Tbx20 showed increased Tbx20, promitotic and angiogenic gene expression, decreased levels of P21, increased Ki67- (17.09±5.73 versus 7.77±7.24 cardiomyocytes/mm2, P<0.05) and PHH3 (phospho-histone H3)-labeled cardiomyocytes (10.10±3.51 versus 5.23±2.87 cardiomyocytes/mm2, P<0.05), and increased capillary (2302.68±353.58 versus 1694.52±211.36 capillaries/mm2, P<0.001) and arteriolar (146.95±53.14 versus 84.06±16.84 arterioles/mm2, P<0.05) densities. At 30 days, Bv-Tbx20 decreased infarct size (9.89±1.92% versus 12.62±1.33%, P<0.05) and slightly improved left ventricular function. Baculoviral gene transfer-mediated Tbx20 overexpression exerted angiogenic and cardiomyogenic effects in vitro.
CONCLUSIONS: In sheep with AMI, Bv-Tbx20 induced angioarteriogenesis, cardiomyocyte cell cycle activity, infarct size limitation, and a slight recovery of left ventricular function, suggesting that Bv-Tbx20 gene therapy may contribute to cardiac regeneration following AMI.
摘要：
背景：基因治疗已被提议作为急性心肌梗死（AMI）后诱导心脏再生的策略。鉴于T-box亚家族的转录因子Tbx20,刺激细胞增殖和血管生成，我们设计了一种杆状病毒过表达Tbx20（Bv-Tbx20），并评估了其在培养的心肌细胞和绵羊AMI模型中的作用。
结果:在用Bv-Tbx20或Bv-Null(对照)转导的心肌细胞中测量细胞增殖和血管生成。随后，在患有AMI的绵羊中，在梗死边界注射Bv-Tbx20或Bv-Null。心肌细胞周期活性,血管生成，左心室功能,评估梗死面积。用BvTbx20转导的心肌细胞增加了细胞增殖，细胞周期调控和血管生成基因表达，和肾小管发生。治疗后7天，用Bv-Tbx20处理的绵羊显示Tbx20增加，促有丝分裂和血管生成基因表达，P21水平降低，Ki67-（17.09±5.73对7.77±7.24心肌细胞/mm2，P<0.05）和PHH3（磷酸组蛋白H3）标记的心肌细胞（10.10±3.51对5.23±2.87心肌细胞/mm2，P<0.05），毛细血管密度增加（2302.68±353.58对1694.52±211.36毛细血管/mm2，P<0.001）和小动脉密度增加（146.95±53.14对84.06±16.84小动脉/mm2，P<0.05）。在30天，Bv-Tbx20减少梗死面积(9.89±1.92%vs12.62±1.33%,P<0.05),左室功能略有改善。杆状病毒基因转移介导的Tbx20过表达在体外发挥血管生成和心肌生成作用。
结论：在患有AMI的绵羊中，Bv-Tbx20诱导血管生成，心肌细胞细胞周期活性，梗死面积限制,左心室功能略有恢复，提示Bv-Tbx20基因治疗可能有助于AMI后的心脏再生。
结果:在用Bv-Tbx20或Bv-Null(对照)转导的心肌细胞中测量细胞增殖和血管生成。随后，在患有AMI的绵羊中，在梗死边界注射Bv-Tbx20或Bv-Null。心肌细胞周期活性,血管生成，左心室功能,评估梗死面积。用BvTbx20转导的心肌细胞增加了细胞增殖，细胞周期调控和血管生成基因表达，和肾小管发生。治疗后7天，用Bv-Tbx20处理的绵羊显示Tbx20增加，促有丝分裂和血管生成基因表达，P21水平降低，Ki67-（17.09±5.73对7.77±7.24心肌细胞/mm2，P<0.05）和PHH3（磷酸组蛋白H3）标记的心肌细胞（10.10±3.51对5.23±2.87心肌细胞/mm2，P<0.05），毛细血管密度增加（2302.68±353.58对1694.52±211.36毛细血管/mm2，P<0.001）和小动脉密度增加（146.95±53.14对84.06±16.84小动脉/mm2，P<0.05）。在30天，Bv-Tbx20减少梗死面积(9.89±1.92%vs12.62±1.33%,P<0.05),左室功能略有改善。杆状病毒基因转移介导的Tbx20过表达在体外发挥血管生成和心肌生成作用。
结论：在患有AMI的绵羊中，Bv-Tbx20诱导血管生成，心肌细胞细胞周期活性，梗死面积限制,左心室功能略有恢复，提示Bv-Tbx20基因治疗可能有助于AMI后的心脏再生。
