Justus A C, Roussev R, Norcross J L, Faulk W P
Methodist Hospital, Indianapolis, IN 46202, USA.
Thromb Res. 1995 Jul 15;79(2):175-86. doi: 10.1016/0049-3848(95)00103-x.
Human umbilical vein endothelial cells cultured in growth media that did not contain exogenous heparin were found to grow less well while binding significantly more antithrombin (AT) than comparable cells cultured in growth media that did contain exogenous heparin (90 micrograms/ml). The binding of AT to plasma membranes of cultured endothelial cells was measured immunologically by flow cytometry. This binding was eliminated completely by reacting the cells with heparinase III before incubating them with AT, indicating that the most likely heparinase-sensitive process responsible for AT binding to plasma membranes was heparan sulfate proteoglycan. Increased AT binding also was promoted by addition of heparin-binding molecules (protamine, AT, or ECGF) to growth media, and the effects of other glycosaminoglycans and dextran on AT binding were found to be dependent on their sulfation. Thus, one response of endothelial cells to heparin deficiency is up-regulation of the ability to bind AT to plasma membranes.
研究发现，在不含外源性肝素的生长培养基中培养的人脐静脉内皮细胞生长较差，但其抗凝血酶（AT）结合量显著高于在含有外源性肝素（90微克/毫升）的生长培养基中培养的同类细胞。通过流式细胞术免疫测定培养的内皮细胞质膜上的AT结合情况。在用AT孵育细胞之前，先用肝素酶III处理细胞，可完全消除这种结合，这表明负责AT与质膜结合的最可能对肝素酶敏感的过程是硫酸乙酰肝素蛋白聚糖。向生长培养基中添加肝素结合分子（鱼精蛋白、AT或表皮细胞生长因子）也会促进AT结合增加，并且发现其他糖胺聚糖和右旋糖酐对AT结合的影响取决于它们的硫酸化程度。因此，内皮细胞对肝素缺乏的一种反应是上调质膜结合AT的能力。
