UCSF/UC Berkeley Joint Graduate Group in Bioengineering, University of California, San Francisco, California, USA.
PLoS Comput Biol. 2011 Apr;7(4):e1002030. doi: 10.1371/journal.pcbi.1002030. Epub 2011 Apr 7.
The study of epithelial morphogenesis is fundamental to increasing our understanding of organ function and disease. Great progress has been made through study of culture systems such as Madin-Darby canine kidney (MDCK) cells, but many aspects of even simple morphogenesis remain unclear. For example, are specific cell actions tightly coupled to the characteristics of the cell's environment or are they more often cell state dependent? How does the single lumen, single cell layer cyst consistently emerge from a variety of cell actions? To improve insight, we instantiated in silico analogues that used hypothesized cell behavior mechanisms to mimic MDCK cystogenesis. We tested them through in vitro experimentation and quantitative validation. We observed novel growth patterns, including a cell behavior shift that began around day five of growth. We created agent-oriented analogues that used the cellular Potts model along with an Iterative Refinement protocol. Following several refinements, we achieved a degree of validation for two separate mechanisms. Both survived falsification and achieved prespecified measures of similarity to cell culture properties. In silico components and mechanisms mapped to in vitro counterparts. In silico, the axis of cell division significantly affects lumen number without changing cell number or cyst size. Reducing the amount of in silico luminal cell death had limited effect on cystogenesis. Simulations provide an observable theory for cystogenesis based on hypothesized, cell-level operating principles.
上皮形态发生的研究对于增加我们对器官功能和疾病的理解至关重要。通过对 Madin-Darby 犬肾 (MDCK) 细胞等培养系统的研究已经取得了很大的进展，但即使是简单形态发生的许多方面仍然不清楚。例如，特定的细胞行为是否与细胞环境的特征紧密耦合，或者它们是否更经常依赖于细胞状态？单一腔室、单层囊肿是如何从各种细胞行为中一致出现的？为了提高认识，我们在计算机中实例化了模拟物，这些模拟物使用假设的细胞行为机制来模拟 MDCK 囊肿发生。我们通过体外实验和定量验证来测试它们。我们观察到了新的生长模式，包括大约在生长的第五天开始的细胞行为转变。我们创建了面向代理的模拟物，使用细胞 Potts 模型和迭代细化协议。经过几次细化，我们实现了两种独立机制的一定程度的验证。这两种机制都经受住了反驳，并达到了细胞培养特性相似性的预定指标。计算机模拟组件和机制与体外对应物相匹配。在计算机模拟中，细胞分裂的轴显著影响管腔数量，而不改变细胞数量或囊肿大小。减少计算机模拟腔室细胞死亡的数量对囊肿发生的影响有限。模拟提供了基于假设的细胞级操作原理的囊肿发生的可观察理论。
