Nakajima Tadaaki, Sasaki Katsunori, Yamamori Akihiro, Sakurai Kengo, Miyata Kaori, Watanabe Tomoyuki, Matsunaga Yukiko T
Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan.
Biomater Sci. 2020 Oct 21;8(20):5615-5627. doi: 10.1039/d0bm00763c. Epub 2020 Sep 18.
The intestine acts as a center for nutrient and water absorption at the epithelium and plays an important role in immunity. Considering the complexity of its function and roles in living systems, a physiologically relevant gut in vitro model is desirable in both basic biology and the analysis of effects of some substances on functions of the gut; these analyses include the screening of drug and food candidates with regard to intestinal disorder at an early stage of medical development. In the present study, we constructed a three-dimensional (3D) gut model using human absorptive enterocytes (CACO-2 cells) by reconstitution of the gut epithelial sheet restricted on a high-reproducible ductal scaffold of collagen gel. Moreover, using the 3D gut model, we evaluated the morphology at the cellular and tissue levels and conducted a phenotypic analysis of the intestinal physiological functions, which involved a permeability assay mimicking barrier disruption inducing inflammation and an absorption assay reflecting ingestive effects. The ductal structure, in vivo-like 3D epithelial structures, epithelial barrier, and effective absorptive function characterized the 3D gut model. The epithelial cells formed a villus-like buckling epithelium, vertical microvilli of increased density on the cell surface, and a crypt-like localized cell proliferating region. The mature shape of the epithelium may contribute to mimicking barrier function and effective absorption compared with that in the 2D gut model. Furthermore, we successfully mimicked the dextran sodium sulfate-induced epithelial barrier dysfunction as a trigger phenomenon of gut inflammation in the 3D gut model. The integrity of the epithelium and phenotypic analysis of the intestinal physiological functions in the simple and reproducible 3D gut model will allow for a drug screening system for assessing the effects on the functions of the gut epithelium from the lumen side.
肠道在上皮细胞处作为营养物质和水分吸收的中心，并且在免疫中发挥重要作用。考虑到其在生命系统中的功能和作用的复杂性，在基础生物学以及分析某些物质对肠道功能的影响方面，都需要一个生理相关的体外肠道模型；这些分析包括在医学研发的早期阶段筛选针对肠道疾病的药物和食品候选物。在本研究中，我们通过在高度可重复的胶原凝胶导管支架上重构肠道上皮片，使用人吸收性肠细胞（CACO-2细胞）构建了三维（3D）肠道模型。此外，我们使用该3D肠道模型评估了细胞和组织水平的形态，并对肠道生理功能进行了表型分析，其中包括模拟屏障破坏诱导炎症的通透性测定以及反映摄取作用的吸收测定。导管结构、体内样的3D上皮结构、上皮屏障和有效的吸收功能是该3D肠道模型的特征。上皮细胞形成绒毛状屈曲上皮、细胞表面密度增加的垂直微绒毛以及隐窝样局部细胞增殖区域。与二维肠道模型相比，上皮的成熟形态可能有助于模拟屏障功能和有效吸收。此外，我们在3D肠道模型中成功模拟了右旋糖酐硫酸钠诱导的上皮屏障功能障碍，作为肠道炎症的触发现象。在简单且可重复的3D肠道模型中上皮的完整性和肠道生理功能的表型分析将有助于建立一个从管腔侧评估对肠道上皮功能影响的药物筛选系统。
