Tissue factor expression in human arterial smooth muscle cells. TF is present in three cellular pools after growth factor stimulation.
Tissue factor expression in human arterial smooth muscle cells. TF is present in three cellular pools after growth factor stimulation.
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DOI：
10.1172/jci119765
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发表时间：
1997-11
期刊：
影响因子：
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通讯作者：
A. Schecter;P. Giesen;O. Taby;C. Rosenfield;M. Rossikhina;B. Fyfe;D. Kohtz;Fallon Jt;Y. Nemerson;M. Taubman
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文献类型：
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作者：
A. Schecter;P. Giesen;O. Taby;C. Rosenfield;M. Rossikhina;B. Fyfe;D. Kohtz;Fallon Jt;Y. Nemerson;M. Taubman
组织因子(Tf)是一种启动凝血级联反应的跨膜糖蛋白。由于转铁蛋白在介导动脉血栓形成中的潜在作用，我们检测了其在人主动脉和冠状动脉平滑肌细胞(SMC)中的表达。多种生长激动剂均可诱导SMC表达Tf基因和蛋白。暴露于PDGF、AA或BB 30min可提供诱导Tf mRNA和蛋白所需的所有信号。这一结果与核径流分析一致，表明PDGF诱导的TF转录发生在30min内。采用地高辛标记的FVIIa(DigVIIa)和地高辛标记的因子X(DigX)结合的新方法来定位细胞内的转铁蛋白。在光镜和共聚焦显微镜下，激动剂作用后2 h，核周胞浆内可见明显的TF染色，持续10~12 h，在SMC单层上测得的表面TF活性一过性升高，在激动剂刺激后4~6 h达到峰值，16 h内恢复到基线水平，峰值仅为细胞裂解物中总TF活性的20%左右。表面因子阻断实验表明，剩余的因子以加密的表面因子形式存在，也存在于胞内池中。TF相对短暂的表面表达可能是限制生长因子刺激下完整的SMC血栓形成潜能的关键。相反，在与SMC损伤相关的条件下，加密的表面池和细胞内池可能提供丰富的TF来源，例如在动脉粥样硬化斑块破裂或球囊动脉损伤期间。
Tissue factor (TF) is a transmembrane glycoprotein that initiates the coagulation cascade. Because of the potential role of TF in mediating arterial thrombosis, we have examined its expression in human aortic and coronary artery smooth muscle cells (SMC). TF mRNA and protein were induced in SMC by a variety of growth agonists. Exposure to PDGF AA or BB for 30 min provided all of the necessary signals for induction of TF mRNA and protein. This result was consistent with nuclear runoff analyses, demonstrating that PDGF-induced TF transcription occurred within 30 min. A newly developed assay involving binding of digoxigenin-labeled FVIIa (DigVIIa) and digoxigenin-labeled Factor X (DigX) was used to localize cellular TF. By light and confocal microscopy, prominent TF staining was seen in the perinuclear cytoplasm beginning 2 h after agonist treatment and persisting for 10-12 h. Surface TF activity, measured on SMC monolayers under flow conditions, increased transiently, peaking 4-6 h after agonist stimulation and returning to baseline within 16 h. Peak surface TF activity was only approximately 20% of total TF activity measured in cell lysates. Surface TF-blocking experiments demonstrated that the remaining TF was found as encrypted surface TF, and also in an intracellular pool. The relatively short-lived surface expression of TF may be critical for limiting the thrombotic potential of intact SMC exposed to growth factor stimulation. In contrast, the encrypted surface and intracellular pools may provide a rich source of TF under conditions associated with SMC damage, such as during atherosclerotic plaque rupture or balloon arterial injury.