Department of Cell Biology and Anatomy, Institute of Biomedicine, University of Turku, Turku, Finland.
Scand J Surg. 2011;100(3):216-22. doi: 10.1177/145749691110000314.
In adult connective tissues, mesenchymal stem cells (MSCs) play a key role in normal tissue turnover and repair. MSCs can participate in these processes not only through proliferation and differentiation but also through paracrine/autocrine functions. These characteristics make MSCs the optimal target in the development of cell-based therapies. This study describes a novel interaction between human MSC and blood mononuclear cells (MNCs), resulting in formation of blood vessel-like structures.
Human marrow-derived MSCs and peripheral blood MNCs were co-cultured in monolayer cultures as well as in bovine collagen sponge up to 20 days. No exogenously supplied growth factors were applied. Morphological changes and formations of three dimensional structures were detected by light microscopy. The process was further stu-died for the expression of different endothelial cell markers. The expression of PECAM-1 and endoglin was studied by immunohistochemistry and the expression of vascular endothelial growth factor receptors 1 and 2 using quantitative real time PCR.
In co-cultures of human MSCs and MNCs, the previously nonadherent cells attached and started to elongate and formed tube-like structures within one week. At day 10, elongated PECAM-1 and endoglin expressing cells were detected in co-cultures. At day 20, PECAM-1 and endoglin-positive vessel-like structures were observed. VEGFR1 was up-regulated in co-cultures after 10 days, and expression levels increased with time. No PECAM-1, endoglin or VEGFR1 expressing cells were discovered in MSC-cultures without MNCs at any time point.
This study demonstrates induction of endothelial differentiation in co-cultures of human MSCs and MNCs, indicating a mechanism by which local application of MSCs could induce angiogenesis in vivo.
在成人结缔组织中，间充质干细胞（MSCs）在正常组织更新和修复中发挥关键作用。MSCs 不仅可以通过增殖和分化参与这些过程，还可以通过旁分泌/自分泌功能参与这些过程。这些特性使 MSCs 成为细胞治疗发展的最佳靶点。本研究描述了人 MSC 与血液单核细胞（MNC）之间的一种新的相互作用，导致血管样结构的形成。
将人骨髓来源的 MSC 和外周血 MNC 单层共培养以及牛胶原蛋白海绵中培养，培养时间长达 20 天。未应用外源性生长因子。通过相差显微镜观察形态变化和三维结构的形成。进一步研究了不同内皮细胞标志物的表达情况。通过免疫组织化学研究了 PECAM-1 和内格林的表达，使用定量实时 PCR 研究了血管内皮生长因子受体 1 和 2 的表达。
在人 MSC 和 MNC 的共培养中，以前非黏附的细胞附着并开始伸长，并在一周内形成管状结构。在第 10 天，共培养物中检测到伸长的 PECAM-1 和内格林表达细胞。在第 20 天，观察到 PECAM-1 和内格林阳性血管样结构。在第 10 天，共培养物中 VEGFR1 上调，表达水平随时间增加。在没有 MNC 的 MSC 培养物中，在任何时间点都没有发现 PECAM-1、内格林或 VEGFR1 表达细胞。
本研究证明了人 MSC 和 MNC 共培养物中内皮细胞分化的诱导，表明局部应用 MSC 可在体内诱导血管生成的机制。
