Estrada C, Bready J V, Berliner J A, Pardridge W M, Cancilla P A
Department of Physiology, Facultad de Medicina, UAM, Madrid, Spain.
J Neuropathol Exp Neurol. 1990 Nov;49(6):539-49. doi: 10.1097/00005072-199011000-00001.
Conditioned medium from isolated cerebral capillary endothelial cells (ECCM) was found to promote DNA synthesis in astrocytes and pericytes, but not in oligodendrocytes or endothelial cells (EC) in vitro. The astrocyte was the cell of primary interest and the cell tested in the following experiments. The effect of ECCM on astrocytes was concentration and time dependent. The growth factor was released by EC into the medium in a cumulative manner for up to 72 hours. This release was not the result of a nonspecific leakage of an internal store, since the DNA synthetic activity of cell lysates was negligible. The growth factor secretion per cell was higher in sparse than in confluent EC cultures and was partially inhibited by preincubation of EC with interleukin-1. The DNA synthetic activity was due to a peptide, different from basic fibroblast growth factor, transferrin, bovine fibronectin and platelet derived growth factor, with a molecular weight greater than 50,000. The peptide derived from the cerebral capillary EC could be involved in the local signaling between cell types that control new vessel formation in development, in regeneration after brain tissue injury, or in tumor formation.
研究发现，从分离的脑毛细血管内皮细胞中提取的条件培养基（ECCM）能促进星形胶质细胞和周细胞的DNA合成，但在体外对少突胶质细胞或内皮细胞（EC）无此作用。星形胶质细胞是主要研究对象，并在后续实验中进行检测。ECCM对星形胶质细胞的作用具有浓度和时间依赖性。生长因子由内皮细胞以累积方式释放到培养基中，持续长达72小时。这种释放并非细胞内储存物质的非特异性泄漏，因为细胞裂解物的DNA合成活性可忽略不计。稀疏培养的内皮细胞比汇合培养的内皮细胞每个细胞分泌的生长因子更多，且内皮细胞与白细胞介素-1预孵育可部分抑制生长因子的分泌。DNA合成活性归因于一种肽，它不同于碱性成纤维细胞生长因子、转铁蛋白、牛纤连蛋白和血小板衍生生长因子，其分子量大于50,000。源自脑毛细血管内皮细胞的这种肽可能参与了不同细胞类型之间的局部信号传导，这种信号传导控制着发育过程中的新血管形成、脑组织损伤后的再生或肿瘤形成。
