在上皮中,细胞密度和细胞增殖通过接触抑制增殖(CIP)而紧密相连。根据细胞密度,CIP经历了三个不同的阶段,即低密度自由生长阶段,中等密度的上皮前过渡阶段,和高密度上皮后过渡阶段。以前的研究已经阐明了细胞形态,动议,和力学在这些阶段有所不同。然而,尚不清楚细胞代谢是否也具有密度依赖性行为。通过测量不同细胞密度下的线粒体膜电位,在这里,我们揭示了上皮代谢的异质景观,在CIP的三个阶段中出现定性差异,并且不遵循其他CIP相关参数的趋势,随着细胞密度的增加而单调增加或减少。重要的是,上皮细胞仅在上皮前过渡阶段建立了集体代谢异质性,高和低电位细胞的多细胞簇出现。然而,在上皮后过渡阶段,代谢势场变得相对均匀。接下来,为了研究潜在的动力学,然后我们构建了一个系统生物学模型,这预测了细胞增殖在建立集体异质性的代谢潜力中的作用。进一步的实验确实表明,代谢模式在空间上与细胞的增殖能力相关,通过促增殖蛋白的核定位来衡量,YAP.最后,干扰肌动球蛋白收缩性的实验表明,虽然在没有肌动球蛋白收缩性的情况下代谢异质性得以维持,它的从头出现取决于后者。一起来看,我们的结果表明,在上皮前过渡阶段上皮单层的代谢领域存在密度依赖性集体异质性,这可能对上皮的形式和功能有重大影响。上皮接触抑制增殖(CIP)在组织稳态中起关键作用,形态发生,和发展。CIP不同阶段细胞的生化变化不像生物物理变化那样有很好的记录。我们揭示了一种异质的代谢景观,在CIP的不同阶段显得截然不同。重要的是,在上皮前过渡阶段,上皮细胞建立了集体代谢异质性,其中高和低电位细胞的多细胞簇出现,尽管细胞的遗传和营养条件一致。集体异质性与几何参数的局部波动和细胞的增殖能力相关。最后,我们证明了细胞力学在建立集体异质性中的作用。
In the epithelium, cell density and cell proliferation are closely connected to each other through contact inhibition of proliferation (CIP). Depending on cell density, CIP proceeds through three distinct stages: the free-growing stage at low density, the pre-epithelial transition stage at medium density, and the post-epithelial transition stage at high density. Previous studies have elucidated how cell morphology, motion, and mechanics vary in these stages. However, it remains unknown whether cellular metabolism also has a density-dependent behavior. By measuring the mitochondrial membrane potential at different cell densities, here we reveal a heterogeneous landscape of metabolism in the epithelium, which appears qualitatively distinct in three stages of CIP and did not follow the trend of other CIP-associated parameters, which increases or decreases monotonically with increasing cell density. Importantly, epithelial cells established a collective metabolic heterogeneity exclusively in the pre-epithelial transition stage, where the multicellular clusters of high- and low-potential cells emerged. However, in the post-epithelial transition stage, the metabolic potential field became relatively homogeneous. Next, to study the underlying dynamics, we constructed a system biology model, which predicted the role of cell proliferation in metabolic potential toward establishing collective heterogeneity. Further experiments indeed revealed that the metabolic pattern spatially correlated with the proliferation capacity of cells, as measured by the nuclear localization of a pro-proliferation protein, YAP. Finally, experiments perturbing the actomyosin contractility revealed that, while metabolic heterogeneity was maintained in the absence of actomyosin contractility, its ab initio emergence depended on the latter. Taken together, our results revealed a density-dependent collective heterogeneity in the metabolic field of a pre-epithelial transition-stage epithelial monolayer, which may have significant implications for epithelial form and function.