Axel D I, Brehm B R, Wolburg-Buchholz K, Betz E L, Köveker G, Karsch K R
Department of Internal Medicine III, University of Tübingen, Germany.
J Vasc Res. 1996 Jul-Aug;33(4):327-39. doi: 10.1159/000159160.
Cell-to-cell interactions are mainly involved in the control of the proliferation, migration, differentiation and function of different cell types in a wide range of tissues. In the arterial vessel wall, human arterial endothelial cells (haEC) and smooth muscle cells (haSMC) coexist in close contact with each other. In atherogenesis, haSMC can migrate from the media to the subintimal space to form fibromuscular and atheromatous plaques. In the present study, a transfilter coculture system is described, in which the interface between haSMC and confluent or proliferative haEC can be studied in detail. Cells were cocultured on the opposite sides of a porous filter which separates both cell types like the internal elastic lamina in vivo. In cocultures containing proliferative haEC, haSMC growth was significantly stimulated (33.4 +/- 5.7 cells/section, p < 0.05) compared to haSMC monocultures (22.9 +/- 2.5 cells/section) and cocultures containing confluent haEC (15.6 +/- 2.9 cells/section). If confluent haEC were injured mechanically, haSMC growth increased highly significantly (71.3 +/- 16.8 cells/section, p < 0.001). Thus, cell-rich proliferates containing 5-7 layers of haSMC embedded in extracellular matrix were formed after 14 days. On the other hand, after haSMC migration to the endothelial side had occurred, the addition of LDL and monocytes to cocultures with arterial media explants and haEC resulted in the formation of lipid-rich, low-cellular structures. After 28 days, characteristic in vitro plaque growth was induced; the plaque contained a lipid core with predominantly necrotic cells, extracellular lipid accumulations, atypically shaped lipid-loaded haSMC and macrophages, similar to in vivo foam cells, as well as an increased amount of extracellular matrix (collagen I, III and IV). These areas were surrounded by typical fibromuscular caps consisting of smooth muscle alpha-actin-positive haSMC. Finally, the formation of capillaries by haEC could also be observed within these structures.
细胞间相互作用主要参与多种组织中不同细胞类型的增殖、迁移、分化及功能的调控。在动脉血管壁中，人动脉内皮细胞（haEC）和平滑肌细胞（haSMC）紧密相邻共存。在动脉粥样硬化形成过程中，haSMC可从血管中膜迁移至内膜下间隙，形成纤维肌性和动脉粥样斑块。在本研究中，描述了一种跨滤器共培养系统，借此可详细研究haSMC与汇合或增殖的haEC之间的界面。细胞在多孔滤器的相对两侧进行共培养，该滤器如同体内的内弹性膜一样分隔两种细胞类型。在含有增殖性haEC的共培养物中，与haSMC单培养物（22.9±2.5个细胞/切片）及含有汇合haEC的共培养物（15.6±2.9个细胞/切片）相比，haSMC的生长受到显著刺激（33.4±5.7个细胞/切片，p<0.05）。若汇合的haEC受到机械损伤，haSMC的生长则极显著增加（71.3±16.8个细胞/切片，p<0.001）。因此，14天后形成了富含细胞的增殖物，其中含有嵌入细胞外基质的5 - 7层haSMC。另一方面，在haSMC迁移至内皮侧后，向与动脉中膜外植体及haEC的共培养物中添加低密度脂蛋白（LDL）和单核细胞，导致形成富含脂质、细胞较少的结构。28天后，诱导出了具有特征性的体外斑块生长；该斑块含有一个脂质核心，主要由坏死细胞、细胞外脂质积聚、形状异常的脂质负载haSMC和巨噬细胞（类似于体内泡沫细胞）以及增加的细胞外基质（I、III和IV型胶原）组成。这些区域被由平滑肌α - 肌动蛋白阳性的haSMC构成的典型纤维肌性帽所包围。最后，在这些结构中还可观察到haEC形成毛细血管。
