Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
Thromb Res. 2013 Jun;131(6):521-8. doi: 10.1016/j.thromres.2013.03.006. Epub 2013 May 1.
Endothelial expression of tissue factor (TF) may play a major role in (Stx)-related hemolytic uremic syndrome. We examined human umbilical vein endothelial cell (HUVEC) monolayers to determine the interaction between TF and TF pathway inhibitor (TFPI), hypothesizing that changes in TFPI modulate TF expression.
We studied 1) cell surface expression of globotriasylceramide (Gb3, the receptor for Stx) with Stx-1 (10 pM), TNFα (20 Ng/ml), or Stx-1 plus TNFα compared to control, 2) gene expression of TF and TFPI, 3) total cellular and cell surface antigenic TF and TFPI, 4) TFPI secretion into supernatant, and 5) factor Xa production.
Gb3 expression, negligible with control and Stx-1 alone, increased significantly with TNFα and with Stx-1 plus TNFα. TF mRNA increased 1.25 ± 0.32- fold (N = 9; p = 0.041) with Stx-1 alone vs. 2.82 ± 0.92-fold (N = 13; p < 0.0005) with TNFα alone. However, Stx-1 plus TNFα yielded a 6.51 ± 3.48-fold increase (N = 17; p < 0.0005). TFPI mRNA decreased with TNFα (p < 0.001) and Stx-1 plus TNFα (p < 0.0005). Total cellular and cell surface TF antigen increased significantly with TNFα, but no further with Stx-1 plus TNFα. Total TFPI cellular and cell surface antigen levels, and TFPI secretion decreased significantly with Stx-1 plus TNFα. Median factor Xa production for Stx-1 plus TNFα vs TNFα alone increased (p < 0.001) 3.24-fold. Our results indicate that a subinhibitory concentration of Stx-1 plus TNFα impairs TFPI gene expression, synthesis, cell-surface association, and secretion, leading to augmented functional TF.
组织因子（TF）在肠出血性大肠杆菌（Stx）相关溶血尿毒综合征中的表达可能起着主要作用。我们检测了人脐静脉内皮细胞（HUVEC）单层细胞，以确定 TF 与 TF 途径抑制剂（TFPI）之间的相互作用，假设 TFPI 的变化调节 TF 的表达。
我们研究了 1）Stx-1（10 pM）、TNFα（20 Ng/ml）或 Stx-1 加 TNFα与对照相比，Gb3（Stx 的受体）在细胞表面的表达，2）TF 和 TFPI 的基因表达，3）总细胞和细胞表面抗原性 TF 和 TFPI，4）TFPI 分泌到上清液中，5）因子 Xa 的产生。
Gb3 表达在对照和 Stx-1 单独作用时可忽略不计，而在 TNFα和 Stx-1 加 TNFα作用时显著增加。TF mRNA 单独用 Stx-1 增加 1.25 ± 0.32-倍（N = 9；p = 0.041），单独用 TNFα增加 2.82 ± 0.92-倍（N = 13；p < 0.0005）。然而，Stx-1 加 TNFα 导致 6.51 ± 3.48-倍的增加（N = 17；p < 0.0005）。TFPI mRNA 随 TNFα（p < 0.001）和 Stx-1 加 TNFα（p < 0.0005）而减少。总细胞和细胞表面 TF 抗原显著增加与 TNFα，但没有进一步的 Stx-1 加 TNFα。总 TFPI 细胞和细胞表面抗原水平和 TFPI 分泌显著降低与 Stx-1 加 TNFα。Stx-1 加 TNFα与 TNFα 相比，因子 Xa 产生的中位数增加（p < 0.001）3.24 倍。我们的结果表明，亚抑制浓度的 Stx-1 加 TNFα 损害 TFPI 基因表达、合成、细胞表面结合和分泌，导致功能性 TF 增加。
