Woo Y Joseph, Panlilio Corinna M, Cheng Richard K, Liao George P, Atluri Pavan, Hsu Vivian M, Cohen Jeffrey E, Chaudhry Hina W
Division of Cardiothoracic Surgery, Department of Surgery, University of Pennsylvania School of Medicine, 3400 Spruce St, Philadelphia PA 19104, USA.
Circulation. 2006 Jul 4;114(1 Suppl):I206-13. doi: 10.1161/CIRCULATIONAHA.105.000455.
Heart failure is a global health concern. As a novel therapeutic strategy, the induction of endogenous myocardial regeneration was investigated by initiating cardiomyocyte mitosis by expressing the cell cycle regulator cyclin A2.
Lewis rats underwent left anterior descending coronary artery ligation followed by peri-infarct intramyocardial delivery of adenoviral vector expressing cyclin A2 (n =32) or empty adeno-null (n =32). Cyclin A2 expression was characterized by Western Blot and immunohistochemistry. Six weeks after surgery, in vivo myocardial function was analyzed using an ascending aortic flow probe and pressure-volume catheter. DNA synthesis was analyzed by proliferating cell nuclear antigen (PCNA), Ki-67, and BrdU. Mitosis was analyzed by phosphohistone-H3 expression. Myofilament density and ventricular geometry were assessed. Cyclin A2 levels peaked at 2 weeks and tapered off by 4 weeks. Borderzone cardiomyocyte cell cycle activation was demonstrated by increased PCNA (40.1+/-2.6 versus 9.3+/-1.1; P<0.0001), Ki-67 (46.3+/-7.2 versus 20.4+/-6.0; P<0.0001), BrdU (44.2+/-13.7 versus 5.2+/-5.2; P<0.05), and phosphohistone-H3 (12.7+/-1.4 versus 0+/-0; P<0.0001) positive cells/hpf. Cyclin A2 hearts demonstrated increased borderzone myofilament density (39.8+/-1.1 versus 31.8+/-1.0 cells/hpf; P=0.0011). Borderzone wall thickness was greater in cyclin A2 hearts (1.7+/-0.4 versus 1.4+/-0.04 mm; P<0.0001). Cyclin A2 animals manifested improved hemodynamics: Pmax (70.6+/-8.9 versus 60.4+/-11.8 mm Hg; P=0.017), max dP/dt (3000+/-588 versus 2500+/-643 mm Hg/sec; P<0.05), preload adjusted maximal power (5.75+/-4.40 versus 2.75+/-0.98 mWatts/microL2; P<0.05), and cardiac output (26.8+/-3.7 versus 22.7+/-2.6 mL/min; P=0.004).
A therapeutic strategy of cyclin A2 expression via gene transfer induced cardiomyocyte cell cycle activation yielded increased borderzone myofilament density and improved myocardial function. This approach of inducing endogenous myocardial regeneration provides proof-of-concept evidence that cyclin A2 may ultimately serve as an efficient, alternative therapy for heart failure.
心力衰竭是一个全球关注的健康问题。作为一种新型治疗策略，通过表达细胞周期调节因子细胞周期蛋白A2启动心肌细胞有丝分裂来研究内源性心肌再生。
对Lewis大鼠进行左前降支冠状动脉结扎，然后在梗死周边心肌内注射表达细胞周期蛋白A2的腺病毒载体（n = 32）或空腺病毒（n = 32）。通过蛋白质印迹法和免疫组织化学对细胞周期蛋白A2的表达进行表征。术后6周，使用升主动脉血流探头和压力-容积导管分析体内心肌功能。通过增殖细胞核抗原（PCNA）、Ki-67和BrdU分析DNA合成。通过磷酸化组蛋白-H3表达分析有丝分裂。评估肌丝密度和心室几何形状。细胞周期蛋白A2水平在2周时达到峰值，并在4周时逐渐下降。PCNA（40.1±2.6对9.3±1.1；P<0.0001）、Ki-67（46.3±7.2对20.4±6.0；P<0.0001）、BrdU（44.2±13.7对5.2±5.2；P<0.05）和磷酸化组蛋白-H3（12.7±1.4对0±0；P<0.0001）阳性细胞/高倍视野增加，证明梗死周边心肌细胞细胞周期激活。细胞周期蛋白A2组心脏梗死周边肌丝密度增加（39.8±1.1对31.8±1.0细胞/高倍视野；P = 0.0011）。细胞周期蛋白A2组心脏梗死周边壁厚度更大（1.7±0.4对1.4±0.04 mm；P<0.0001）。细胞周期蛋白A2组动物表现出改善的血流动力学：最大压力（70.6±8.9对60.4±11.8 mmHg；P = 0.017）、最大dp/dt（3000±588对2500±643 mmHg/秒；P<0.05）、预负荷调整后的最大功率（5.75±4.40对2.75±0.98 mWatt/μL2；P<0.05）和心输出量（26.8±3.7对22.7±2.6 mL/分钟；P = 0.004）。
通过基因转移表达细胞周期蛋白A2的治疗策略诱导心肌细胞细胞周期激活，使梗死周边肌丝密度增加，心肌功能改善。这种诱导内源性心肌再生的方法提供了概念验证证据，表明细胞周期蛋白A2最终可能成为心力衰竭的一种有效替代疗法。
