Conditioned medium from endothelial cell cultures can restore the normal phenotypic expression of vascular endothelium maintained in vitro in the absence of fibroblast growth factor.
Conditioned medium from endothelial cell cultures can restore the normal phenotypic expression of vascular endothelium maintained in vitro in the absence of fibroblast growth factor.
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来自内皮细胞培养物的条件培养基可以恢复在不存在成纤维细胞生长因子的情况下体外维持的血管内皮的正常表型表达。
DOI：
10.1002/jcp.1041030219
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发表时间：
1980
影响因子：
5.6
通讯作者：
Gospodarowicz,D
中科院分区：
文献类型：
--
作者：
Greenburg,G;Vlodavsky,I;Foidart,JM;Gospodarowicz,D
在FGF存在下连续维持和生长的牛血管内皮细胞在汇合时采用由接触抑制细胞组成的细胞单层的构型，这些细胞不会彼此过度生长，并且高度扁平且紧密贴壁。这种培养物表现出与其体内对应物相似的结构和形态特征。这些包括细胞外基质的产生，主要由基底膜胶原蛋白和纤连蛋白组成，仅位于细胞单层下方，但不在其顶部，以及非血栓形成的血液相容性顶端细胞表面。从成年牛主动脉内皮细胞（ABAE）培养物中去除成纤维细胞生长因子（FGF）导致细胞在三次传代内丧失其特征性接触抑制形态。细胞在对数生长期分裂，倍增时间大大增加，变得更大，更长。汇合培养物，而不是采用接触抑制细胞单层的形态，现在由过度生长的细胞组成。与培养物内发生的形态学改变平行，细胞也失去了血管内皮细胞表面特征的极性。在顶细胞和基底细胞表面均观察到主要由纤连蛋白和I型、III型和IV型胶原组成的细胞外基质的形成。以前不能与顶端细胞表面结合的血小板现在能够与顶端细胞表面结合。CSP-60是一种存在于高度融合和接触抑制的血管内皮细胞培养物中的主要细胞表面蛋白，不再能检测到。在FGF的存在下生长的细胞条件培养基中保持融合的内皮细胞培养物，但在达到融合时保持其不存在，在4至8天内导致改变的表型的逆转。该培养基具有很少或没有促有丝分裂活性，并且在不存在血清的情况下或通过明胶-琼脂糖柱上的亲和色谱法耗尽其纤连蛋白含量后保留完全活性。先前由多层生长的细胞组成的培养物重组成由紧密贴壁和高度扁平的细胞组成的单细胞单层。因此，培养物恢复了血管内皮的接触抑制形态特征。伴随着这种细胞重组，细胞外基质从顶端细胞表面消失，细胞恢复了其非血栓形成特性，CSP-60重新成为主要的细胞表面蛋白之一。这些结果表明，血管内皮细胞分泌可溶性因子，其可以恢复从培养基中去除FGF后丧失的正常形态和功能。这种因子可能参与维持血管内皮的分化状态。
Bovine vascular endothelial cells continuously maintained and grown in the presence of FGF adopt at confluence the configuration of a cell monolayer composed of contact‐inhibited cells which do not overgrow each other and which are highly flattened and closely apposed. Such cultures exhibit structural and morphological characteristics similar to those observed with their in vivo counterparts. These include the production of an extracellular matrix consisting mostly of basement membrane collagen and fibronectin localized exclusively beneath the cell monolayer, but not on top of it, as well as a nonthrombogenic, blood‐compatible apical cell surface. Removal of fibroblast growth factor (FGF) from adult bovine aortic endothelial cell (ABAE) cultures results within three passages in the loss by the cells of their characteristic contact‐inhibited morphology. The cells, which during their logarithmic growth phase divide with a greatly increased doubling time, become larger and more elongated. Confluent cultures, instead of adopting the morphology of a contact inhibited cell monolayer, are now composed of overgrowing cells. Parallel with the morphological alterations taking place within the culture, the cells also lose the polarity of cell surfaces characteristics of the vascular endothelium. Formation of an extracellular matrix composed primarily of fibronectin and collagen types I, III, and IV is observed on both the apical and basal cell surfaces. Platelets which previously did not bind to the apical cell surface now become capable of binding to it. CSP‐60, a major cell surface protein present in highly confluent and contact‐inhibited vascular endothelial cell cultures, can no longer be detected. Exposure of confluent endothelial cell cultures, maintained in the absence of FGF to medium conditioned by cells which had been grown in the presence of FGF, but maintained in its absence upon reaching confluence led, within four to eight days, to a reversion of the altered phenotype. This medium has little or no mitogenic activity and retains a full activity in the absence of serum or after depletion of its fibronectin content by affinity chromatography on a gelatin‐Sepharose column. Cultures which were previously composed of cells growing in multiple layers reorganized into a single cell monolayer composed of closely apposed and highly flattened cells. The cultures thereby regained the contact‐inhibited morphology characteristic of the vascular endothelium. Concomitant with this cellular reorganization, the extracellular matrix disappeared from the apical cell surface, the cells regained their nonthrombogenic properties, and CSP‐60 reappeared as one of the major cell surface proteins. These results suggest that vascular endothelial cells secrete a soluble factor(s) which can restore the normal morphology and function lost following removal of FGF from the medium. Such a factor(s) may be involved in maintaining the differentiated state of the vascular endothelium.