Costa Manoel L, de Andrade Rosa Ivone, Andrade Leonardo, Mermelstein Claudia, C Coutinho Cristiano
Institute of Biomedical Sciences, Federal University of Rio de Janeiro - UFRJ, Rio de Janeiro, RJ, Brazil.
J Morphol. 2020 Feb;281(2):183-195. doi: 10.1002/jmor.21090. Epub 2019 Dec 19.
Epithelial and mesenchymal cell types are basic for animal multicellularity and they have complementary functions coordinated by cellular interactions. Sponges are especially important model organisms to address the evolutionary basis of morphogenetic programs for epithelial and mesenchymal organization in animals. Evolutionary studies in sponges can contribute to the understanding of the mechanisms that control tissue maintenance and tumor progression in humans. In the present study, sponge mesenchymal and epithelial cells were isolated from the demosponge Hymeniacidon heliophila, and aggregate formation was observed by video microscopy. Epithelial-mesenchymal interaction, epithelial transition, and cell migration led to sponge cell aggregation after drastic stress. Based on their different morphologies, adhesion specificities, and motilities, we suggest a role for different sponge cell types as well as complementary functions in cell aggregation. Micromanipulation under the microscope and cell tracking were also used to promote specific grafting-host interaction, to further test the effects of cell type interaction. The loss of cell polarity and flattened shape during the epithelial to mesenchymal cell transition generated small immobile aggregates of round/amoeboid cells. The motility of these transited epithelial-cell aggregates was observed by cell tracking using fluorescent dye, but only after interaction with streams of migratory mesenchymal cells. Cell motility occurred independently of morphological changes, indicating a progressive step in the transition toward a migratory mesenchymal state. Our data suggest a two-step signaling process: (a) the lack of interaction between mesenchymal and epithelial cells triggers morphological changes; and (b) migratory mesenchymal cells instruct epithelial cells for directional cell motility. These results could have an impact on the understanding of evolutionary aspects of metastatic cancer cells. HIGHLIGHTS: Morphogenetic movements observed in modern sponges could have a common evolutionary origin with collective cell migration of human metastatic cells. A sponge regenerative model was used here to characterize epithelial and mesenchymal cells, and for the promotion of grafting/host interactions with subsequent cell tracking. The transition from epithelial to mesenchymal cell type can be observed in sponges in two steps: (a) withdrawal of epithelial/mesenchymal cell interactions to trigger morphological changes; (b) migratory mesenchymal cells to induce epithelial cells to a collective migratory state.
上皮细胞和间充质细胞类型是动物多细胞性的基础，它们具有通过细胞间相互作用协调的互补功能。海绵是研究动物上皮和间充质组织形态发生程序进化基础的特别重要的模式生物。对海绵的进化研究有助于理解控制人类组织维持和肿瘤进展的机制。在本研究中，从海绵 Hymeniacidon heliophila 中分离出间充质细胞和上皮细胞，并通过视频显微镜观察聚集形成。在剧烈应激后，上皮 - 间充质相互作用、上皮转变和细胞迁移导致海绵细胞聚集。基于它们不同的形态、黏附特异性和运动性，我们提出不同海绵细胞类型在细胞聚集中的作用以及互补功能。还使用显微镜下的显微操作和细胞追踪来促进特定的移植 - 宿主相互作用，以进一步测试细胞类型相互作用的影响。上皮细胞向间充质细胞转变过程中细胞极性的丧失和扁平形状产生了圆形/变形虫状细胞的小的不动聚集体。使用荧光染料通过细胞追踪观察这些转变的上皮细胞聚集体的运动性，但仅在与迁移的间充质细胞流相互作用之后。细胞运动独立于形态变化发生，表明向迁移间充质状态转变的一个渐进步骤。我们的数据表明一个两步信号过程：(a) 间充质细胞和上皮细胞之间缺乏相互作用触发形态变化；(b) 迁移的间充质细胞指导上皮细胞进行定向细胞运动。这些结果可能对理解转移性癌细胞的进化方面产生影响。要点：在现代海绵中观察到的形态发生运动可能与人类转移性细胞的集体细胞迁移有共同的进化起源。这里使用海绵再生模型来表征上皮细胞和间充质细胞，并促进移植/宿主相互作用以及随后的细胞追踪。在海绵中可以观察到上皮细胞向间充质细胞类型的转变分两步进行：(a) 上皮/间充质细胞相互作用的撤回触发形态变化；(b) 迁移的间充质细胞诱导上皮细胞进入集体迁移状态。
