Development of Combination Therapy Between Myocardial Regeneration and Ventricular Assist Device Support

本研究的目的是评价基因治疗或细胞移植等联合治疗在心脏再生和心脏辅助装置支持中的作用。当我从奈良医科大学搬到国家心血管中心研究所时，我开始了这项研究。首先，我们研究了一种在脑室辅助系统(VAS)下对山羊急性心肌梗死血管生成的基因疗法。6只成年山羊(56-65公斤)通过结扎冠状动脉造成心脏受损，并安装搏动性双VAD。肝细胞生长因子(HGF)是一种血管生成因子基因，也具有心脏保护作用。HGF组(n=3)，心肌内注射人HGF-cDNA2.0 mg。对照组(n=3)给予同样的β-半乳糖苷酶质粒。基因转导4周后，所有的山羊都试图摆脱VADS。转染人肝细胞生长因子基因的心肌细胞含有a…水平的人肝细胞生长因子蛋白。更多的S在3天后高达1.0+/-0.3 ng/g组织。停用VADS后，HGF组血流动力学良好，而对照组血流动力学恶化。HGF组短轴缩短率显著高于对照组(37.9±1.7%vs.26.4±0.3%，p&lt；0.01)。对照组可见左室扩张伴心肌细胞肥大和纤维化改变，而肝细胞生长因子组未见。HGF组血管密度明显增加。这些结果表明，使用hHGF的基因治疗可以增加VAS下受损心脏的“桥接恢复”的机会。第二，我们研究了一种细胞移植治疗左VAD支持的山羊心肌病(LVAD)。成年山羊4只，体重55.7+/-3.2 kg，用阿霉素灌胃5周建立心力衰竭模型。所有山羊均安装了搏动性左心室起搏装置，并维持了充分的体循环。4只山羊中有2只输注体外培养的自体骨髓基质细胞(BMSC)(BMSC组)，其余2只不输注(对照组)。所有山羊均持续支持4周，并连续记录心功能和血流动力学。骨髓间充质干细胞组的心功能恢复情况(左心室射血分数，从39.3+/-2.3%到47.0+/-14.0%)明显好于对照组(从32.6+/-0.7%到26.0+/-4.3%)。与对照组相比，BMSC组心肌壁变薄受到更多的抑制。结论：对严重衰竭的心功能加用LVAD支持的再生治疗可能有助于心功能的恢复，增加桥接恢复的可能性。较少

The purpose of this study is to evaluate the usefulness of combination therapy between ventricular assist device(VAD) support and cardiac regeneration such as gene therapy or cell transplantation. I started this study when I moved from Nara Medical University to National Cardiovascular Center Research Institute.First, we examined a gene therapy for angiogenesis to acute myocardial infarction in goats under ventricular assist system(VAS). Six adult goats (56-65kg) were created the impaired heart by ligating the coronary artery and installed pulsatile bi-VADs. Hepatocyte Growth Factor(HGF) was selected as a gene of an angiogenesis factor, which also has cardioprotective activities. The HGF group (n=3) administered human HGF-cDNA plasmid of 2.0 mg in myocardium. The control group (n=3) administered beta-galactosidase plasmid similarly. Four weeks after gene transfection, all goats were tried to wean from VADs. The myocardia transfected with the hHGF-cDNA contained hHGF protein at levels a … More s high as 1.0+/-0.3 ng/g tissue 3 days after transfection. After weaning from VADs, the HGF group showed good hemodynamics while the control group showed its deterioration. The percent fractional shortening was significantly higher in the HGF group than the control group (HGF vs.control,37.9+/-1.7% vs.26.4+/-0.3%, p<0.01). LV dilatation associated with myocytes hypertorcphy and fibrotic changes were detected in the control group while not in the HGF group. Vascular density was markedly increased in the HGF group. These results suggest that gene therapy using hHGF may enhance the chance of "bridge to recovery" in the impaired heart under VAS.Second, we examined a cell transplantation to cardiomyopathy in goats supported with left VAD(LVAD). Four adult goats weighing 55.7+/-3.2 kg were created heart failure by infusing adriamycin for 5 weeks. All goats were instaled a pulsatile LVAD and maintained systmic circulation sufficiently. Two of 4 goats were infused autologus bone marrow-derived stromal cells(BMSC) which were previously cultured in vitro(BMSC group), and the rest 2 goats were not infused them (control group). All goats were continued LVAD support for 4 weeks, and cardiac function and hemodynamics were serially recorded. The BMSC group recovered better cardiac function (the LV Ejection Fraction (EF) ; from 39.3+/-2.3% to 47.0+/-14.0%) than the control group did (EF ; from 32.6+/-0.7% to 26.0+/-4.3%). Wall thinning of the myocardium was more suppressed in the BMSC group than that in the control group.In conclusion, additional regeneration therapy to severe failing heart supported with LVAD may contribute to recover cardiac function and increase the possibility of bridge to recovery. Less