Shin Woojung, Wu Alexander, Min Soyoun, Shin Yong Cheol, Fleming R Y Declan, Eckhardt S Gail, Kim Hyun Jung
Department of Biomedical Engineering, The University of Texas at Austin, 107 W. Dean Keeton St., Austin, TX 78712, USA.
Department of Oncology, Dell Medical School, The University of Texas at Austin, Austin, TX 78712, USA; Department of Surgery and Perioperative Care, Dell Medical School, The University of Texas at Austin, Austin, TX 78712, USA.
iScience. 2020 Aug 21;23(8):101372. doi: 10.1016/j.isci.2020.101372. Epub 2020 Jul 16.
In a conventional culture of three-dimensional human intestinal organoids, extracellular matrix hydrogel has been used to provide a physical space for the growth and morphogenesis of organoids in the presence of exogenous morphogens such as Wnt3a. We found that organoids embedded in a dome-shaped hydrogel show significant size heterogeneity in different locations inside the hydrogel. Computational simulations revealed that the instability and diffusion limitation of Wnt3a constitutively generate a concentration gradient inside the hydrogel. The location-dependent heterogeneity of organoids in a hydrogel dome substantially perturbed the transcriptome profile associated with epithelial functions, cytodifferentiation including mucin 2 expression, and morphological characteristics. This heterogeneous phenotype was significantly mitigated when the Wnt3a was frequently replenished in the culture medium. Our finding suggests that the morphological, transcriptional, translational, and functional heterogeneity in conventional organoid cultures may lead to a false interpretation of the experimental results in organoid-based studies.
在三维人类肠道类器官的传统培养中，细胞外基质水凝胶已被用于在存在外源性形态发生素（如Wnt3a）的情况下为类器官的生长和形态发生提供物理空间。我们发现，嵌入圆顶形水凝胶中的类器官在水凝胶内部的不同位置表现出显著的大小异质性。计算模拟表明，Wnt3a的不稳定性和扩散限制在水凝胶内部持续产生浓度梯度。水凝胶圆顶中类器官的位置依赖性异质性极大地扰乱了与上皮功能、包括粘蛋白2表达在内的细胞分化以及形态特征相关的转录组谱。当在培养基中频繁补充Wnt3a时，这种异质表型得到了显著缓解。我们的发现表明，传统类器官培养中的形态、转录、翻译和功能异质性可能导致基于类器官的研究中实验结果的错误解读。
