Tattersall Ian W, Du Jing, Cong Zhuangzhuang, Cho Bennet S, Klein Alyssa M, Dieck Chelsea L, Chaudhri Reyhaan A, Cuervo Henar, Herts James H, Kitajewski Jan
Obstetrics/Gynecology, Columbia University, New York, NY, USA.
Pathology and Cell Biology, Columbia University, New York, NY, USA.
Angiogenesis. 2016 Apr;19(2):201-15. doi: 10.1007/s10456-016-9501-1. Epub 2016 Mar 10.
Angiogenesis is regulated by complex interactions between endothelial cells and support cells of the vascular microenvironment, such as tissue myeloid cells and vascular mural cells. Multicellular interactions during angiogenesis are difficult to study in animals and challenging in a reductive setting. We incorporated stromal cells into an established bead-based capillary sprouting assay to develop assays that faithfully reproduce major steps of vessel sprouting and maturation. We observed that macrophages enhance angiogenesis, increasing the number and length of endothelial sprouts, a property we have dubbed "angiotrophism." We found that polarizing macrophages toward a pro-inflammatory profile further increased their angiotrophic stimulation of vessel sprouting, and this increase was dependent on macrophage Notch signaling. To study endothelial/pericyte interactions, we added vascular pericytes directly to the bead-bound endothelial monolayer. These pericytes formed close associations with the endothelial sprouts, causing increased sprout number and vessel caliber. We found that Jagged1 expression and Notch signaling are essential for the growth of both endothelial cells and pericytes and may function in their interaction. We observed that combining endothelial cells with both macrophages and pericytes in the same sprouting assay has multiplicative effects on sprouting. These results significantly improve bead-capillary sprouting assays and provide an enhanced method for modeling interactions between the endothelium and the vascular microenvironment. Achieving this in a reductive in vitro setting represents a significant step toward a better understanding of the cellular elements that contribute to the formation of mature vasculature.
血管生成受血管微环境中内皮细胞与支持细胞（如组织髓样细胞和血管壁细胞）之间复杂相互作用的调节。血管生成过程中的多细胞相互作用在动物中难以研究，在简化环境中也具有挑战性。我们将基质细胞纳入已建立的基于珠子的毛细血管芽生试验中，以开发能够忠实地重现血管芽生和成熟主要步骤的试验。我们观察到巨噬细胞可增强血管生成，增加内皮芽的数量和长度，我们将这一特性称为“血管营养作用”。我们发现将巨噬细胞极化为促炎表型会进一步增强其对血管芽生的血管营养刺激，且这种增加依赖于巨噬细胞Notch信号传导。为了研究内皮细胞/周细胞相互作用，我们将血管周细胞直接添加到与珠子结合的内皮单层中。这些周细胞与内皮芽形成紧密关联，导致芽数量增加和血管管径增大。我们发现Jagged1表达和Notch信号传导对于内皮细胞和周细胞的生长均至关重要，并且可能在它们的相互作用中发挥作用。我们观察到在同一芽生试验中将内皮细胞与巨噬细胞和周细胞结合对芽生具有倍增效应。这些结果显著改进了珠子 - 毛细血管芽生试验，并提供了一种增强的方法来模拟内皮细胞与血管微环境之间的相互作用。在简化的体外环境中实现这一点代表了朝着更好地理解促成成熟脉管系统形成的细胞成分迈出的重要一步。
