Lee Eujin, Takahashi Haruko, Pauty Joris, Kobayashi Masayoshi, Kato Keisuke, Kabara Maki, Kawabe Jun-Ichi, Matsunaga Yukiko T
Center for International Research on Integrative Biomedical Systems (CIBiS), Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan.
J Mater Chem B. 2018 Feb 21;6(7):1085-1094. doi: 10.1039/c7tb03239k. Epub 2018 Feb 5.
Angiogenesis, which refers to the formation of new blood vessels from already existing vessels, is a promising therapeutic target and a complex multistep process involving many different factors. Pericytes (PCs) are attracting attention as they are considered to make significant contributions to the maturation and stabilisation of newly formed vessels, although not much is known about the precise mechanisms involved. Since there is no single specific marker for pericytes, in vivo models may complicate PC identification and the study of PCs in angiogenesis would benefit from in vitro models recapitulating the interactions between PCs and endothelial cells (ECs) in a three-dimensional (3D) configuration. In this study, a 3D in vitro co-culture microvessel model incorporating ECs and PCs was constructed by bottom-up tissue engineering. Angiogenesis was induced in the manner of sprout formation by the addition of a vascular endothelial cell growth factor. It was found that the incorporation of PCs prevented expansion of the parent vessel diameter and enhanced sprout formation and elongation. Physical interactions between ECs and PCs were visualised by immunostaining and it disclosed that PCs covered the EC monolayer from its basal side in the parent vessel as well as angiogenic sprouts. Furthermore, the microvessels were visualized in 3D by using a non-invasive optical coherence tomography (OCT) imaging system and sprout features were quantitatively assessed. It revealed that the sprouts in EC-PC co-culture vessels were longer and tighter than those in EC mono-culture vessels. The combination of the microvessel model and the OCT system analysis can be useful for the visualisation and demonstration of the multistep process of angiogenesis, which incorporates PCs.
血管生成是指从已有的血管形成新的血管，它是一个有前景的治疗靶点，也是一个涉及许多不同因素的复杂多步骤过程。周细胞（PCs）正受到关注，因为它们被认为对新形成血管的成熟和稳定有重大贡献，尽管对其中的确切机制了解不多。由于周细胞没有单一的特异性标志物，体内模型可能会使周细胞的识别复杂化，而血管生成中周细胞的研究将受益于能够在三维（3D）结构中重现周细胞与内皮细胞（ECs）之间相互作用的体外模型。在本研究中，通过自下而上的组织工程构建了一种包含内皮细胞和周细胞的三维体外共培养微血管模型。通过添加血管内皮细胞生长因子以芽生形成的方式诱导血管生成。研究发现，周细胞的加入阻止了母血管直径的扩大，并增强了芽生的形成和伸长。通过免疫染色观察到内皮细胞和周细胞之间的物理相互作用，结果显示周细胞从母血管以及血管生成芽的基底侧覆盖内皮细胞单层。此外，使用非侵入性光学相干断层扫描（OCT）成像系统对微血管进行三维可视化，并对芽的特征进行定量评估。结果显示，内皮细胞 - 周细胞共培养血管中的芽比内皮细胞单培养血管中的芽更长且更紧密。微血管模型与OCT系统分析相结合，可用于可视化和展示包含周细胞的血管生成多步骤过程。
