INJURY-INDUCED RELEASE OF BASIC FIBROBLAST GROWTH-FACTOR FROM BOVINE AORTIC ENDOTHELIUM
INJURY-INDUCED RELEASE OF BASIC FIBROBLAST GROWTH-FACTOR FROM BOVINE AORTIC ENDOTHELIUM
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DOI：
10.1002/jcp.1041390317
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发表时间：
1989-06-01
影响因子：
5.6
通讯作者：
CARBON, S
中科院分区：
文献类型：
--
作者：
GAJDUSEK, CM;CARBON, S
虽然碱性成纤维细胞生长因子（bFGF）基因缺乏指示分泌的传统共有信号肽结构域，但许多细胞类型具有bFGF的受体。由于内皮细胞是一个丰富的来源，细胞相关的碱性成纤维细胞生长因子，我们问在什么条件下可以释放或分泌的牛主动脉内皮细胞（BAE）融合培养。将BAE细胞裂解物中的bFGF水平与完整BAE细胞单层、具有暴露的细胞外基质的完整细胞（非裂解基质）和通过细胞裂解制备的细胞外基质（裂解基质）中的肝素可释放bFGF水平进行比较。不到10%的总细胞相关的碱性成纤维细胞生长因子从完整的细胞单层和非裂解基质释放。相反，从裂解基质释放的bFGF的水平取决于用于制备基质的条件。在中性pH下的细胞裂解产生释放最高bFGF水平（约50%的总细胞相关bFGF）的基质。这些基质被组蛋白严重污染，表明细胞释放和细胞内蛋白质吸附到基质上。BAE细胞暴露于碱性pH（100 mM NH 4 OH）制备的基质含有低bFGF含量和轻微的组蛋白污染。后者的矩阵被选择来研究bFGF螯合，在生理条件下，融合BAE细胞培养物的细胞外基质。与内毒素（一种对BAE细胞有急性毒性的试剂）一起孵育，导致细胞释放内源性bFGF并将其吸附到细胞和基质中，伴随着基质中的组蛋白沉积。这些结果表明，从BAE细胞单层释放bFGF的机制之一是被动释放诱导严重的细胞损伤和/或细胞裂解与二次吸附到基质。
Although the basic fibroblast growth factor (bFGF) gene lacks a traditional consensus signal peptide domain indicative for secretion, many cell types have receptors for bFGF. Since endothelium is a rich source of cell-associated bFGF, we asked under what conditions could bFGF be released or secreted from confluent cultures of bovine aortic endothelial (BAE) cells. The level of bFGF in BAE cell lysates was compared with the level of heparin-releasable bFGF in intact BAE cell monolayers, intact cells with exposed extracellular matrix (nonlytic matrices), and extracellular matrices prepared by cell lysis (lytic matrices). Less than 10% of total cell-associated bFGF was released from intact cell monolayers and nonlytic matrices. In contrast, the levels of bFGF released from lytic matrices depended upon the conditions used to prepare the matrices. Cell lysis at neutral pH generated matrices that released the highest bFGF levels (approximately 50% of total cell-associated bFGF). These matrices were heavily contaminated by histones, indicating the cellular release and adsorption of intracellular proteins to the matrix. Matrices prepared by BAE cell exposure to basic pH (100 mM NH4OH) contained low bFGF content and minor histone contamination. These latter matrices were chosen to study bFGF sequestration, under physiological conditions, into the extracellular matrix of confluent BAE cell cultures. Incubation with endotoxin, an agent acutely toxic to BAE cells, resulted in cellular release and adsorption of endogenous bFGF to cells and matrices, accompanied by histone deposition in the matrices. These results suggested that one mechanism for bFGF release from BAE cell monolayers was passive release induced by severe cell injury and/or cell lysis with secondary adsorption to the matrix.