Tension development and nuclear eccentricity in topographically controlled cardiac syncytium
Tension development and nuclear eccentricity in topographically controlled cardiac syncytium
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DOI：
10.1023/a:1024551614629
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发表时间：
2003-06-01
影响因子：
2.8
通讯作者：
Bien, H
中科院分区：
文献类型：
--
作者：
Entcheva, E;Bien, H
本研究的目的是利用具有三维表面的微加工支架进行地形控制，以诱导工程化心肌合胞体（一种具有重建的细胞间连接和同步的类组织行为的高密度心肌细胞结构）产生主动张力并增强收缩性。使用聚二甲基硅氧烷模塑设计了具有深微沟槽（特征高度为50μm）的弹性支架，并使新生大鼠心肌细胞在其上生长至汇合。与在各种平面（F）上生长的相比，在地形修饰（T）支架上的工程化心肌细胞构建体显示出更高层次的细胞内和细胞间组织（纤维状结构），并产生了自组织的持续电活动和机械活动。这些结构和功能变化伴随着核偏心度在统计学上显著（p < 0.001）的增加（平均值±标准误：T组为0.79 ± 0.01，n = 137；F组为0.64 ± 0.01，n = 863），以及优先的核取向，以浅角度偏离沟槽轴。在T样本中，细胞核的取向与肌动蛋白纤维排列以及最大位移方向密切相关。地形诱导的核变形是张力产生的标志，意味着转录和细胞信号传导方面的进一步功能变化。总之，我们证明了在没有外部机械或电刺激的情况下，对工程化心肌合胞体的机电特性进行地形控制。这些发现表明在设计具有重建的可兴奋组织的生物自主力发生器时，有可能利用可控的微环境。
The goal of this study was to use topographic control by microfabricated scaffolds with 3-dimensional surfaces to induce active tension development and enhanced contractility in engineered cardiac syncytium (a high density cardiac cell structure with reconstituted cell-to-cell connections and synchronized tissue-like behavior). Deeply microgrooved (feature height 50mum) elastic scaffolds were designed using polydimethylsiloxane molding, and neonatal rat cardiomyocytes were grown on them to confluency. Engineered cardiac cell constructs on the topographically modified (T) scaffolds showed higher order of intra and intercellular organization (fiber-like structures) compared to those grown on various flat surfaces (F), and developed self-organized persisting electrical and mechanical activity. These structural and functional changes were accompanied by a statistically significant (p < 0.001) increase in nuclear eccentricity (mean +/- S.E.: 0.79 +/- 0.01, n = 137 in T vs. 0.64 +/- 0.01, n 863 in F), and a preferential nuclear orientation, deviating from the axis of the grooves at a shallow angle. The orientation of the nuclei correlated well with the actin fiber arrangement in the T-samples, as well as with the direction of maximum displacement. Topography-induced nuclear deformation, a sign of tension development, implies further functional changes in transcription and cell signaling. In conclusion, we demonstrate topographic control of electromechanics in engineered cardiac syncytium, without external mechanical or electrical stimulation. These findings suggest a possibility to use controled microenvironments in the design of biological autonomous force generators with reconstituted excitable tissue.