Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8505, Japan.
Department of Science, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama, Kanagawa, 236-0027, Japan.
Stem Cell Res Ther. 2022 Dec 27;13(1):532. doi: 10.1186/s13287-022-03223-1.
Sprouting angiogenesis is an important mechanism for morphogenetic phenomena, including organ development, wound healing, and tissue regeneration. In regenerative medicine, therapeutic angiogenesis is a clinical solution for recovery from ischemic diseases. Mesenchymal stem cells (MSCs) have been clinically used given their pro-angiogenic effects. MSCs are reported to promote angiogenesis by differentiating into pericytes or other vascular cells or through cell-cell communication using multiple protein-protein interactions. However, how MSCs physically contact and move around ECs to keep the sprouting angiogenesis active remains unknown.
We proposed a novel framework of EC-MSC crosstalk analysis using human umbilical vein endothelial cells (HUVECs) and MSCs obtained from mice subcutaneous adipose tissue on a 3D in vitro model, microvessel-on-a-chip, which allows cell-to-tissue level study. The microvessels were fabricated and cultured for 10 days in a collagen matrix where MSCs were embedded.
Immunofluorescence imaging using a confocal laser microscope showed that MSCs smoothed the surface of the microvessel and elongated the angiogenic sprouts by binding to the microvessel's specific microstructures. Additionally, three-dimensional modeling of HUVEC-MSC intersections revealed that MSCs were selectively located around protrusions or roots of angiogenic sprouts, whose surface curvature was excessively low or high, respectively.
The combination of our microvessel-on-a-chip system for 3D co-culture and image-based crosstalk analysis demonstrated that MSCs are selectively localized to concave-convex surfaces on scaffold structures and that they are responsible for the activation and stabilization of capillary vessels.
发芽性血管生成是形态发生现象的重要机制，包括器官发育、伤口愈合和组织再生。在再生医学中，治疗性血管生成是缺血性疾病恢复的临床解决方案。间充质干细胞 (MSC) 因其促血管生成作用而在临床上得到应用。据报道，MSC 通过分化为周细胞或其他血管细胞，或通过多种蛋白-蛋白相互作用进行细胞间通讯，促进血管生成。然而，MSC 如何与 EC 物理接触并移动以保持发芽性血管生成的活性仍然未知。
我们提出了一种使用人脐静脉内皮细胞 (HUVEC) 和从小鼠皮下脂肪组织获得的 MSC 在 3D 体外模型，即微血管芯片上进行 EC-MSC 串扰分析的新框架，该模型允许进行细胞到组织水平的研究。在胶原基质中制造和培养微血管 10 天，其中嵌入了 MSC。
使用共聚焦激光显微镜进行的免疫荧光成像显示，MSC 通过与微血管的特定微结构结合，使微血管表面光滑，并使血管生成芽伸长。此外，HUVEC-MSC 交叉点的三维建模表明，MSC 选择性地位于血管生成芽的突起或根部周围，其表面曲率分别过低或过高。
我们的微血管芯片系统用于 3D 共培养和基于图像的串扰分析的结合表明，MSC 选择性地定位于支架结构上的凹凸表面，并且它们负责毛细血管的激活和稳定。
