Gospodarowicz D, Gonzalez R, Fujii D K
J Cell Physiol. 1983 Feb;114(2):191-202. doi: 10.1002/jcp.1041140208.
The possibilities that the growth-promoting effect of the extracellular matrix (ECM) produced by cultured bovine corneal endothelial (BCE) cells could be due to: (1) adsorbed cellular factors released during the cell lysis process leading to the denudation of the ECM; (2) adsorbed serum or plasma factors: or (3) adsorbed exogenous growth factors have been examined. Exposure of confluent BCE cultures to 2 M urea in medium supplemented with 0.5% calf serum denudes the ECM without cell lysis. The ECM prepared by this procedure supports cell growth just as well as ECM prepared by denudation involving cell lysis. Thus, it is unlikely that the growth-promoting properties of ECM are due to adsorbed cellular factors. When the ECM produced by BCE cells grown in defined medium supplemented with high-density lipoprotein, transferrin, and insulin was compared to the ECMs produced by cells grown in the presence of serum- or plasma-supplemented medium, all were found to be equally potent in stimulating cell growth. It is therefore unlikely that the growth-promoting ability of the ECM is due to adsorbed plasma or serum components. When fibroblast growth factor (FGF)-coated and ECM-coated plastic dishes were submitted to a heat treatment (70 degrees C, 30 min) which results in the inactivation of FGF, the growth-supporting ability of FGF-coated dishes was lost, while the comparable ability of ECM-coated dishes was not affected significantly. This observation tends to demonstrate that the active factor present in the ECM is not FGF. Nor is it platelet-derived growth factor (PDGF), since treatment known to destroy the activity of PDGF, such as exposure to dithiothreitol (0.1 M, 30 min, 22 degrees C) or to beta-mercaptoethanol (10%) in the presence or absence of 6 M urea for 30 min at 22 degrees C, does not affect the growth-promoting activity of ECM. It is therefore unlikely that the growth-promoting effect of ECM is due to cellular growth-promoting agents or to plasma or serum factors adsorbed onto the ECM.
培养的牛角膜内皮（BCE）细胞产生的细胞外基质（ECM）的促生长作用可能归因于以下几种可能性：（1）细胞裂解过程中释放的吸附细胞因子导致ECM剥脱；（2）吸附的血清或血浆因子；或（3）吸附的外源性生长因子，这些都已被研究过。在补充有0.5%小牛血清的培养基中，将汇合的BCE培养物暴露于2 M尿素中可使ECM剥脱而不发生细胞裂解。通过此程序制备的ECM支持细胞生长的效果与通过涉及细胞裂解的剥脱制备的ECM一样好。因此，ECM的促生长特性不太可能归因于吸附的细胞因子。当将在补充有高密度脂蛋白、转铁蛋白和胰岛素的限定培养基中生长的BCE细胞产生的ECM与在补充有血清或血浆的培养基中生长的细胞产生的ECM进行比较时，发现所有这些在刺激细胞生长方面同样有效。因此，ECM的促生长能力不太可能归因于吸附的血浆或血清成分。当将涂有成纤维细胞生长因子（FGF）和涂有ECM的塑料培养皿进行热处理（70℃，30分钟），这会导致FGF失活时，涂有FGF的培养皿的生长支持能力丧失，而涂有ECM的培养皿的类似能力未受到显著影响。这一观察结果倾向于证明ECM中存在的活性因子不是FGF。也不是血小板衍生生长因子（PDGF），因为已知破坏PDGF活性的处理，如在22℃下暴露于二硫苏糖醇（0.1 M，30分钟）或在有或无6 M尿素存在下暴露于β-巯基乙醇（10%）30分钟，不会影响ECM的促生长活性。因此，ECM的促生长作用不太可能归因于细胞促生长剂或吸附在ECM上的血浆或血清因子。
