Left-right symmetry breaking in tissue morphogenesis via cytoskeletal mechanics.
Left-right symmetry breaking in tissue morphogenesis via cytoskeletal mechanics.
复制标题
通过细胞骨架力学打破组织形态发生的左右对称性
DOI：
10.1161/circresaha.111.255927
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发表时间：
2012-02-17
影响因子：
20.1
通讯作者：
Demer LL
中科院分区：
文献类型：
--
作者：
Chen TH;Hsu JJ;Zhao X;Guo C;Wong MN;Huang Y;Li Z;Garfinkel A;Ho CM;Tintut Y;Demer LL
基本原理：左右（LR）不对称在动物发育中普遍存在。细胞骨架手性最近报道，以指定LR不对称的胚胎发生，这表明LR不对称的组织形态是由单细胞或多细胞组织者协调。因此，为了在形态发生的多尺度水平上组织LR不对称性，具有手性的细胞也必须以足够的数量存在。然而，LR不对称性的观察很少报道在培养的细胞。目的：使用培养的血管间充质细胞，我们测试LR不对称是否发生在单细胞水平和自组织的多细胞结构。方法和结果：使用micropatterning，免疫荧光显示，成人血管细胞极化的神经元和积累的应力纤维在一个公正的机械界面之间的粘合剂和非粘合剂基板。绿色荧光蛋白转染显示，细胞在界面处各自转向平行，在汇合时相对于界面轴以20°对齐成连贯取向。在随后的聚集阶段，延时视频显微镜显示细胞沿沿着相同的20°角迁移到相邻的聚集体中，导致具有LR不对称性的宏观尺度结构，如在整个培养物中均匀间隔的平行对角线条纹。去除基板接口的阴影掩模电镀，或抑制Rho激酶或非肌肉肌球蛋白衰减应力纤维的积累和废除LR不对称的单细胞极性和多细胞的连贯性，这表明接口触发不对称通过细胞骨架力学。其他细胞类型的检查表明，LR不对称性是细胞类型特异性的。结论：我们的研究结果表明，成人干细胞保留固有的LR不对称elevening从头宏观组织形态发生，表明机械诱导细胞LR规格。
Rationale: Left-right (LR) asymmetry is ubiquitous in animal development. Cytoskeletal chirality was recently reported to specify LR asymmetry in embryogenesis, suggesting that LR asymmetry in tissue morphogenesis is coordinated by single- or multi-cell organizers. Thus, to organize LR asymmetry at multiscale levels of morphogenesis, cells with chirality must also be present in adequate numbers. However, observation of LR asymmetry is rarely reported in cultured cells. Objectives: Using cultured vascular mesenchymal cells, we tested whether LR asymmetry occurs at the single cell level and in self-organized multicellular structures. Methods and Results: Using micropatterning, immunofluorescence revealed that adult vascular cells polarized rightward and accumulated stress fibers at an unbiased mechanical interface between adhesive and nonadhesive substrates. Green fluorescent protein transfection revealed that the cells each turned rightward at the interface, aligning into a coherent orientation at 20° relative to the interface axis at confluence. During the subsequent aggregation stage, time-lapse videomicroscopy showed that cells migrated along the same 20° angle into neighboring aggregates, resulting in a macroscale structure with LR asymmetry as parallel, diagonal stripes evenly spaced throughout the culture. Removal of substrate interface by shadow mask-plating, or inhibition of Rho kinase or nonmuscle myosin attenuated stress fiber accumulation and abrogated LR asymmetry of both single-cell polarity and multicellular coherence, suggesting that the interface triggers asymmetry via cytoskeletal mechanics. Examination of other cell types suggests that LR asymmetry is cell-type specific. Conclusions: Our results show that adult stem cells retain inherent LR asymmetry that elicits de novo macroscale tissue morphogenesis, indicating that mechanical induction is required for cellular LR specification.