复杂的微环境信号在组织形态发生过程中协调影响细胞行为和命运。然而,关于特定局部生态位信号如何影响细胞行为和命运的潜在机制还没有完全理解,由于缺乏体外平台,定量,空间,并独立操纵个体生态位信号。这里,基于蛋白质的3D单细胞微生态位(3D-SCμN)的微阵列,精确设计的生物物理和生化生态位信号,通过多光子微加工和微图案化技术进行微印刷。小鼠胚胎干细胞(mESC)作为模型细胞,以研究局部生态位信号如何影响干细胞的行为和命运。通过精确设计3DSCμNs的内部微结构,我们证明细胞分裂方向可以由生物物理小生境信号控制,以细胞形状独立的方式。将细胞分裂方向限制在主导轴后,单个mESC暴露于不对称的生化生态位信号,具体来说,一侧的细胞-细胞粘附分子和另一侧的细胞外基质。我们证明,对称破缺(不对称)小生境信号成功触发细胞极性形成,并偏置不对称细胞分裂的方向,有丝分裂过程导致两个具有不同命运的子细胞,在mESC中。
Intricate microenvironment signals orchestrate to affect cell behavior and fate during tissue morphogenesis. However, the underlying mechanisms on how specific local niche signals influence cell behavior and fate are not fully understood, owing to the lack of in vitro platform able to precisely, quantitatively, spatially, and independently manipulate individual niche signals. Here, microarrays of protein-based 3D single cell micro-niche (3D-SCμN), with precisely engineered biophysical and biochemical niche signals, are micro-printed by a multiphoton microfabrication and micropatterning technology. Mouse embryonic stem cell (mESC) is used as the model cell to study how local niche signals affect stem cell behavior and fate. By precisely engineering the internal microstructures of the 3D SCμNs, we demonstrate that the cell division direction can be controlled by the biophysical niche signals, in a cell shape-independent manner. After confining the cell division direction to a dominating axis, single mESCs are exposed to asymmetric biochemical niche signals, specifically, cell-cell adhesion molecule on one side and extracellular matrix on the other side. We demonstrate that, symmetry-breaking (asymmetric) niche signals successfully trigger cell polarity formation and bias the orientation of asymmetric cell division, the mitosis process resulting in two daughter cells with differential fates, in mESCs.