Hannan R L, Kourembanas S, Flanders K C, Rogelj S J, Roberts A B, Faller D V, Klagsbrun M
Division of Hematology, Children's Hospital, Boston, MA 02115.
Growth Factors. 1988;1(1):7-17. doi: 10.3109/08977198809000242.
Endothelial cells, including human umbilical vein endothelial cells (HUVEC), bovine aortic endothelial cells (BAEC), and bovine capillary endothelial cells (BCEC) in culture synthesize basic fibroblast growth factor (bFGF) and transforming growth factor type beta (TGF-beta). Basic FGF was cell-associated and synthesis was demonstrated by (i) the presence of bFGF mRNA species, (ii) binding to heparin-Sepharose and elution at 1.5 M NaCl, (iii) cross-reactivity with anti-bFGF antibodies when analyzed by electrophoretic blotting, and (iv) biological activity. Basic FGF was found in cell lysates at 2.3 ng/10(6) cells in HUVEC, 2.0 ng/10(6) cells in BCEC, and 13 ng/10(6) cells in BAEC. TGF-beta was secreted into media, and synthesis was demonstrated by (i) presence of TGF-beta mRNA species, (ii) cross-reactivity with anti-TGF-beta antibodies when analyzed by immunoprecipitation, (iii) competitive binding with authentic human platelet-derived TGF-beta that was blocked by TGF-beta specific blocking antibodies, and (iv) inhibition of [3H]TdR incorporation in CCl-64 cells. TGF-beta was secreted in an inactive form and required acid activation for detection. HUVEC synthesized 2.0 ng TGF-beta/10(6) cells per 12 hr; BCEC, 3.5 ng; and BAEC, 3.5 ng. HUVEC proliferation was not affected by treatment with exogenous TGF-beta, while BCEC proliferation was decreased by treatment with TGF-beta. Vascular endothelium is thus a source for these two potent multifunctional regulatory molecules, both of which may affect the growth of endothelium and neighboring fibroblasts, smooth muscle cells and white blood cells. The activation or release of these factors by endothelium may be a precipitating event in important cellular processes such as wound healing, organogenesis, and angiogenesis.
培养中的内皮细胞，包括人脐静脉内皮细胞（HUVEC）、牛主动脉内皮细胞（BAEC）和牛毛细血管内皮细胞（BCEC），能合成碱性成纤维细胞生长因子（bFGF）和转化生长因子β型（TGF-β）。碱性FGF与细胞相关，其合成通过以下方式得以证明：（i）存在bFGF mRNA种类；（ii）与肝素-琼脂糖结合并在1.5 M NaCl中洗脱；（iii）通过电泳印迹分析时与抗bFGF抗体发生交叉反应；（iv）具有生物活性。在HUVEC的细胞裂解物中发现碱性FGF的含量为2.3 ng/10⁶细胞，BCEC中为2.0 ng/10⁶细胞，BAEC中为13 ng/10⁶细胞。TGF-β分泌到培养基中，其合成通过以下方式得以证明：（i）存在TGF-β mRNA种类；（ii）通过免疫沉淀分析时与抗TGF-β抗体发生交叉反应；（iii）与真实的人血小板衍生TGF-β竞争性结合，该结合被TGF-β特异性阻断抗体阻断；（iv）抑制CCl-64细胞中[³H]TdR的掺入。TGF-β以无活性形式分泌，检测时需要酸激活。HUVEC每12小时每10⁶细胞合成2.0 ng TGF-β；BCEC为3.5 ng；BAEC为3.5 ng。外源性TGF-β处理不影响HUVEC的增殖，而TGF-β处理会使BCEC的增殖减少。因此，血管内皮是这两种强大的多功能调节分子的来源，这两种分子都可能影响内皮细胞以及相邻的成纤维细胞、平滑肌细胞和白细胞的生长。内皮细胞对这些因子的激活或释放可能是诸如伤口愈合、器官发生和血管生成等重要细胞过程中的一个触发事件。
