Growth of engineered human myocardium with mechanical loading and vascular coculture.
Growth of engineered human myocardium with mechanical loading and vascular coculture.
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DOI：
10.1161/circresaha.110.237206
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发表时间：
2011-06-24
影响因子：
20.1
通讯作者：
Murry CE
中科院分区：
文献类型：
--
作者：
Tulloch NL;Muskheli V;Razumova MV;Korte FS;Regnier M;Hauch KD;Pabon L;Reinecke H;Murry CE
发育中的心脏需要机械负荷和血管化才能达到适当的大小，但人们对这些过程对人类心脏生长的调节知之甚少。我们试图利用组织工程方法阐明未成熟的人类心肌对机械负荷和血管化的反应。在三维胶原基质中使用人类胚胎干细胞和人类诱导多能干细胞衍生的心肌细胞，我们发现单轴机械应力调节可促进心肌细胞和基质纤维排列增加两倍，并增强肌原纤维生成和肌节带。此外，与未应变的结构相比，循环应变显着增加心肌细胞肥大（2.2 倍）和增殖率（21%）。添加内皮细胞可增强所有应激条件下的心肌细胞增殖（14% 至 19%），添加基质支持细胞可将血管样结构的形成增强约 10 倍。此外，这些优化的人体心脏组织结构会产生 Starling 曲线，随着静息长度的增加而增加其主动力。当移植到无胸腺大鼠的心脏时，人类心肌存活并形成与宿主心肌紧密贴合的移植物。移植物含有由宿主冠状循环灌注的人体微血管。我们的结果表明机械负荷和血管细胞共培养都控制心肌细胞增殖，并且机械负荷进一步控制工程化人类心肌的肥大和结构。这种结构可用于研究人类心脏发育以及再生治疗。
The developing heart requires both mechanical load and vascularization to reach its proper size, yet the regulation of human heart growth by these processes is poorly understood. We seek to elucidate the responses of immature human myocardium to mechanical load and vascularization using tissue engineering approaches. Using human embryonic stem cell and human induced pluripotent stem cell-derived cardiomyocytes in a three dimensional collagen matrix, we show that uniaxial mechanical stress conditioning promotes 2-fold increases in cardiomyocyte and matrix fiber alignment and enhances myofibrillogenesis and sarcomeric banding. Furthermore, cyclic strain markedly increases cardiomyocyte hypertrophy (2.2-fold) and proliferation rates (21%) vs. unstrained constructs. Addition of endothelial cells enhances cardiomyocyte proliferation under all stress conditions (14% to 19%), and addition of stromal supporting cells enhances formation of vessel-like structures by ~10-fold. Furthermore, these optimized human cardiac tissue constructs generate Starling curves, increasing their active force in response to increased resting length. When transplanted onto hearts of athymic rats, the human myocardium survives and forms grafts closely apposed to host myocardium. The grafts contain human microvessels that are perfused by the host coronary circulation. Our results indicate that both mechanical load and vascular cell co-culture control cardiomyocyte proliferation, and that mechanical load further controls the hypertrophy and architecture of engineered human myocardium. Such constructs may be useful for studying human cardiac development as well as for regenerative therapy.