Gajdusek C M, Luo Z, Mayberg M R
Department of Neurological Surgery, University of Washington, Seattle.
J Cell Physiol. 1993 Oct;157(1):133-44. doi: 10.1002/jcp.1041570118.
We investigated the relative roles of basic fibroblast growth factor (bFGF) and transforming growth factor beta-1 (TGF-b) on bovine aortic endothelial cell mitogenesis and morphogenesis using two-dimensional Petri dish cultures and a three-dimensional hydrated collagen gel. bFGF alone stimulated endothelial cell proliferation with an EC50 of 0.5 ng/ml. At bFGF levels greater than 2.5 ng/ml, morphologic alterations in confluent monolayers predominated; cells changed from a cobblestone morphology to an elongated cell pattern and showed enhanced migration into a denuded area of a Petri dish. In the three-dimensional model, exposure of endothelial cell monolayers to high bFGF levels stimulated minor cell migration directly under the monolayer but no invasion into the gel matrix. In combination with bFGF, heparin potentiated morphogenic changes, but not mitogenesis. bFGF modification of the antiproliferative effect of TGF-b in confluent cultures was evidenced by induction of endothelial cell sprouting in response to 0.5 ng/ml TGF-b and 10-20 ng/ml bFGF in two-dimensional cultures. On collagen gels, endothelial cells migrated into the deep layers of the gel in a dose-dependent manner: invasion was maximal at 0.3-0.7 ng/ml TGF-b with decreased invasion at higher concentrations. The optimal collagen concentration that supported cell invasion was 0.075% collagen with the number of invading cells decreasing with increasing collagen gel density. By scanning electron microscopy, invading endothelial cells assumed a fibroblast-like appearance with slender cell extensions. We concluded that bFGF and TGF-b had independent effects on endothelial cell morphology and mitogenesis in culture. In combination at specific doses, these agents stimulated sprouting in the two-dimensional model and cell invasion in a collagen gel model. Morphogenic changes may be the primary event in determining angiogenesis.
我们使用二维培养皿培养和三维水合胶原凝胶，研究了碱性成纤维细胞生长因子（bFGF）和转化生长因子β-1（TGF-β）在牛主动脉内皮细胞有丝分裂和形态发生中的相对作用。单独的bFGF以0.5 ng/ml的EC50刺激内皮细胞增殖。在bFGF水平大于2.5 ng/ml时，汇合单层细胞的形态改变占主导；细胞从鹅卵石形态变为细长细胞模式，并显示出向培养皿裸露区域的迁移增强。在三维模型中，将内皮细胞单层暴露于高bFGF水平会刺激单层正下方的少量细胞迁移，但不会侵入凝胶基质。与bFGF联合使用时，肝素增强了形态发生变化，但没有增强有丝分裂。在二维培养中，bFGF对汇合培养物中TGF-β抗增殖作用的修饰表现为，对0.5 ng/ml TGF-β和10 - 20 ng/ml bFGF的反应诱导内皮细胞发芽。在胶原凝胶上，内皮细胞以剂量依赖性方式迁移到凝胶深层：在0.3 - 0.7 ng/ml TGF-β时侵袭最大，在更高浓度时侵袭减少。支持细胞侵袭的最佳胶原浓度为0.075%胶原，随着胶原凝胶密度增加，侵袭细胞数量减少。通过扫描电子显微镜观察，侵袭的内皮细胞呈现出成纤维细胞样外观，细胞延伸细长。我们得出结论，bFGF和TGF-β对培养中的内皮细胞形态和有丝分裂有独立作用。在特定剂量下联合使用时，这些因子在二维模型中刺激发芽，在胶原凝胶模型中刺激细胞侵袭。形态发生变化可能是决定血管生成的主要事件。
