Institute of Advanced Biomedical Engineering and Science, Tokyo Women's Medical University (TWIns), Tokyo, Japan.
Tissue Eng Part A. 2011 Dec;17(23-24):2973-80. doi: 10.1089/ten.tea.2010.0659. Epub 2011 Aug 29.
Regenerative therapies have currently emerged as one of the most promising treatments for repair of the damaged heart. Recently, numerous researchers reported that isolated cell injection treatments can improve heart function in myocardial infarction models. However, significant cell loss due to primary hypoxia or cell wash-out and difficulty to control the location of the grafted cells remains problem. As an attempt to overcome these limitations, we have proposed cell sheet-based tissue engineering, which involves stacking confluently cultured cells (two-dimensional), cell sheets, to construct three-dimensional cell-dense tissues. Cell sheet transplantation has been able to recover damaged heart function. However, no detailed analysis for transplanted cell survival has been previously performed. The present study compared the survival of cardiac cell sheet transplantation to direct cell injection in a rat myocardial infarction model. Luciferase-expressing neonatal rat cardiac cells were harvested as cell sheets from temperature-responsive culture dishes. The transplantation of cell sheets was compared to the direct injection of isolated cells dissociated with trypsin-ethylenediaminetetraacetic acid. These grafts were transplanted to infarcted rat hearts and cardiac function was assessed by echocardiography at 2 and 4 weeks after transplantation. In vivo bioluminescence and histological analyses were performed to examine cell survival. Cell sheet transplantation consistently yielded greater cell survival than cell injection. Immunohistochemistry revealed that cardiac cell sheets existed over the infarcted area as an intact layer. In contrast, the injected cells were scattered with relatively few cardiomyocytes in the infarcted areas. Four weeks after transplantation, cardiac function was also significantly improved in the cell sheet transplantation group compared with the cell injection. Twenty-four hours after cell grafting, significantly greater numbers of mature capillaries were also observed in the cardiac cell sheet transplantation. Additionally, the numbers of apoptotic cells with deterioration of integrin-mediated attachment were significantly lower after cardiac cell sheet transplantation. In accordance with increased cell survival, cardiac function was significantly improved after cardiac cell sheet transplantation in comparison to cell injection. Cell sheet transplantation can repair damaged hearts through improved cell survival and should become a promising therapy in cardiovascular regenerative medicine.
再生疗法目前已成为修复受损心脏最有前途的治疗方法之一。最近，许多研究人员报告称，分离细胞注射治疗可改善心肌梗死模型中的心脏功能。然而，由于原发性缺氧或细胞冲洗导致的大量细胞丢失以及难以控制移植细胞的位置仍然是问题。为了克服这些限制，我们提出了基于细胞片的组织工程，该方法涉及将密集培养的细胞（二维）堆叠成细胞片，以构建三维密集的细胞组织。细胞片移植已能够恢复受损的心脏功能。但是，以前没有对移植细胞的存活进行详细分析。本研究比较了心脏细胞片移植和直接细胞注射在大鼠心肌梗死模型中的效果。从温度响应培养皿中收获表达荧光素酶的新生大鼠心脏细胞作为细胞片。将细胞片的移植与用胰蛋白酶-乙二胺四乙酸分离的分离细胞的直接注射进行比较。将这些移植物移植到梗死大鼠心脏中，并在移植后 2 周和 4 周通过超声心动图评估心脏功能。进行体内生物发光和组织学分析以检查细胞存活。细胞片移植比细胞注射更能提高细胞存活率。免疫组织化学显示，心脏细胞片作为一个完整的层存在于梗死区域之上。相比之下，在梗死区域中注射的细胞散布着相对较少的心肌细胞。移植后 4 周，与细胞注射组相比，细胞片移植组的心脏功能也显著改善。细胞移植后 24 小时，在心脏细胞片移植组中还观察到成熟毛细血管的数量明显增加。此外，心脏细胞片移植后，整合素介导的附着恶化的凋亡细胞数量明显减少。与细胞存活率增加一致，与细胞注射相比，心脏细胞片移植可显著改善心脏功能。细胞片移植可通过改善细胞存活来修复受损心脏，有望成为心血管再生医学中的一种有前途的治疗方法。
