INITIATION OF THE COAGULATION CASCADE BY VASCULAR CELLS

转录调控、信使核糖核酸稳定性和 翻译后事件被认为与控制 组织因子(TF)表达。这项研究的目标是 阐明导致这一现象的多种分子机制 这种分子的细胞表面表达，它负责 血管细胞“启动”凝血酶的级联反应 (即单核细胞和内皮细胞)。序列分析 新分离的人类转铁蛋白基因已经确定了区域 假定具有启动子和增强子活性，包括 预测的转录因子结合位点数。顺位- 转铁蛋白基因的作用调节区负责 转录调控，包括细胞类型特异性和 特定激动剂的诱导性，将通过转染法进行定位 和定点突变。转染法实验 未经修饰的DNA可能不能反映所有水平的转铁蛋白基因控制；a DNA甲基化的假定作用(在“HTF”内和两侧 岛“区域)在调控TF基因活性时也会 调查过了。转录后控制将被调查 在转铁蛋白mRNA周转水平上。蛋白质的参与 加工、转运和降解是在调节中假设的 活跃的转铁蛋白分子出现在细胞表面；这些 将探索各种过程。了解TF表达式是如何 在血管隔间的调节将是一个至关重要的 对理解老年人正常生理调节的贡献 凝血系统与血管内病变的发病机制 凝血、血栓形成状态和继发性炎症 回应。

A complex pattern of transcriptional control, mRNA stability and post-translational events has been implicated in the control of tissue factor (TF) expression. The goal of this study is to elucidate the multiple molecular mechanisms that bring about the cell-surface expression of this molecule which is responsible for "initiation" of the coagulation protease cascade by vascular cells (i.e., the monocyte and the endothelial cell). Sequence analysis of the newly isolated human TF gene has identified regions postulated to possess promoter and enhancer activity, including a number of predicted transcription factor binding sites. The cis- acting regulatory regions of the TF gene responsible for transcriptional control, including cell-type-specificity and inducibility by specific agonists, will be mapped by transfection and site-directed mutagenesis. Transfection experiments with unmodified DNA may not reflect all levels of TF gene control; a postulated role for DNA methylation (within and flanking the "HTF island" region) in the regulation of TF gene activity will also be investigated. Post-transcriptional control will be investigated at the level of TF mRNA turnover. Involvement of protein processing, transit and degradation is hypothesized in regulating the appearance of active TF molecules on the cell surface; these processes will be explored. Understanding how TF expression is regulated in the vascular compartment will be a crucial contribution to understanding normal physiologic regulation of the coagulation system as well as the pathogenesis of intravascular coagulation, the thrombogenic state, and secondary inflammatory responses.