Mueller S N, Thomas K A, Di Salvo J, Levine E M
Wistar Institute, Philadelphia, Pennsylvania 19104.
J Cell Physiol. 1989 Sep;140(3):439-48. doi: 10.1002/jcp.1041400306.
The effects of heparin and other glycosaminoglycans (GAGs) on the mitogenicity and stability of acidic fibroblast growth factor (aFGF) were studied. The mitogenic activity of aFGF was assayed utilizing cultured adult human endothelial cells (AHECs) isolated from iliac arteries and veins as target cells. In most experiments, aFGF purified from bovine brain was employed; in some experiments recombinant bovine aFGF was used and qualitatively similar results were obtained. In the presence of heparin, bovine aFGF at doses between 0.5 and 1.0 ng/ml (30-60 pM) elicited half the maximum AHEC growth over a 4-day period depending on the cell line tested; in the absence of heparin, significant growth was not observed at aFGF concentrations less than 10-20 ng/ml. This effect of heparin was dose-dependent over the range 0.1-10 micrograms/ml (half-maximum dose, 2 micrograms/ml). The mitogenic activity of bovine aFGF for AHECs decreased by 50% after preincubation in culture medium without cells at 37 degrees C for 2 1/2 to 3 hours. In contrast, the mitogenic activity of bovine aFGF preincubated in the presence of heparin-containing culture medium without cells was dramatically stabilized (half-life 24-29 hours). These effects also were observed in serum-free medium. Several GAGs structurally related to heparin such as chondroitin-4-sulfate, chondroitin-6-sulfate, dermatan sulfate, and hyaluronic acid neither potentiated nor stabilized aFGF mitogenic activity. However, heparan sulfate from bovine lung was found to be nearly as active as heparin in both these effects. These data suggest that the binding and stabilization of mitogens by extracellular and tissue-associated heparan sulfates might play important roles in the regulation of AHEC growth.
研究了肝素和其他糖胺聚糖（GAGs）对酸性成纤维细胞生长因子（aFGF）的促有丝分裂活性和稳定性的影响。利用从髂动脉和静脉分离的培养成人人类内皮细胞（AHECs）作为靶细胞来测定aFGF的促有丝分裂活性。在大多数实验中，使用从牛脑纯化的aFGF；在一些实验中使用重组牛aFGF，获得了定性相似的结果。在肝素存在的情况下，根据所测试的细胞系，0.5至1.0 ng/ml（30 - 60 pM）剂量的牛aFGF在4天内引发了最大AHEC生长的一半；在没有肝素的情况下，当aFGF浓度低于10 - 20 ng/ml时未观察到显著生长。肝素的这种作用在0.1 - 10微克/毫升范围内呈剂量依赖性（半数最大剂量，2微克/毫升）。牛aFGF对AHECs的促有丝分裂活性在37℃无细胞的培养基中预孵育2.5至3小时后降低了50%。相比之下，在无细胞的含肝素培养基中预孵育的牛aFGF的促有丝分裂活性显著稳定（半衰期24 - 29小时）。在无血清培养基中也观察到了这些作用。几种与肝素结构相关的GAGs，如硫酸软骨素-4、硫酸软骨素-6、硫酸皮肤素和透明质酸，既不增强也不稳定aFGF的促有丝分裂活性。然而，发现来自牛肺的硫酸乙酰肝素在这两种作用中几乎与肝素一样活跃。这些数据表明，细胞外和组织相关的硫酸乙酰肝素对有丝分裂原的结合和稳定可能在AHEC生长的调节中起重要作用。
