An Investigation of the Expression of Thrombomodulin in Cultured Human Umbilical Vein Endothelial Cells

我们研究了血栓调节蛋白在培养的人脐静脉内皮细胞（HUVEC）和人巨核母细胞白血病细胞系MEG-01中的表达，得到以下结果：1) 3 ~ 5 mM dbcAMP孵育细胞可上调细胞表面血栓调节蛋白的表达。HUVEC组细胞表面TM增加约250%，meg -01组细胞表面TM增加约600%。其他药物如IBMX、福斯可林、前列环素，增加细胞内cAMP，也增加细胞表面血栓调节素。3)细胞表面凝血调节蛋白IL-1和TNF - α降低约50%。4)在血栓调节蛋白基因组上游未发现cAMP响应元件。5)转染人血栓调节蛋白cDNA构建的CHO细胞表达两种类型的血栓调节蛋白。一种分子量为75000道尔顿的凝血调节蛋白被认为是凝血调节蛋白。另一种具有17万道尔顿的凝血调节蛋白被表达并命名为2型凝血调节蛋白。CHO细胞表达两种血栓调节蛋白的量相等。6)免疫印迹法检测两种血栓调节蛋白的表达比例。正常培养的HUVEC表达2型血栓调节蛋白约5%。

We investigated the expression of thrombomodulin in cultured human umbilical vein endothelial cells(HUVEC) and human megakaryoblastic leukemia cell line, MEG-01 and got the following results.1) An incubation of the cell swith 3-5 mM dbcAMP upregulated the expression of cellsurface throbomodulin. The cell-surface TM was increased by aproximately by 250 % in HUVEC and by 600 % in MEG-01.2) The other agents such as IBMX, forskolin, prostacyclin, which increase in intracellular cAMP, also increase in the cell-surface thrombomodulin.3) IL-1 and TNF alpha, however, decreased in the cell-surface thrombomodulin by about 50 %.4) We could not find so called cAMP responsive element in the upstream of thrombomodulin genome.5) Two type of thrombomodulin is expressed in CHO cells which constructed by the transfection of human thrombomodulin cDNA. A thrombomodulin with a molecular weight of 75, 000 dalton has been recognized as thrombomodulin. Another thrombomdulin with the 170, 000 dalton is expressed and designated as type 2 thrombomodulin. CHO cells expressed both type of thrombomodulin by equal amount.6) The expression ratio of two type of thrombomodulin was examined by immunoblotting. HUVEC in normal culture expressed type two thrombomodulin about 5 %.