Premium
Activated protein C suppresses tissue factor expression on U937 cells in the endothelial protein C receptor‐dependent manner
Author(s) -
Shu Fang,
Kobayashi Hiroshi,
Fukudome Kenji,
Tsuneyoshi Naoko,
Kimoto Masao,
Terao Toshihiko
Publication year - 2000
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(00)01740-3
Subject(s) - endothelial protein c receptor , u937 cell , microbiology and biotechnology , tissue factor , protein c , receptor , cell culture , phorbol , chemistry , monoclonal antibody , flow cytometry , biology , antibody , protein kinase c , biochemistry , signal transduction , thrombin , immunology , medicine , platelet , genetics , coagulation
The new functional role of activated protein C (APC) in the regulation of tissue factor (TF) expression was investigated using the cultured human monoblastic leukemia U937 cell line. A flow cytofluorometric analysis demonstrated that treatment with APC resulted in time‐ and dose‐dependent decrease in TF expression in unstimulated and phorbol ester‐stimulated cells. The effect was antagonized by the monoclonal antibody (mAb) to endothelial protein C/APC receptor (EPCR), 252, which strongly inhibited the interaction between APC and EPCR. In contrast, mAbs 49 and 379, which bind to EPCR without blocking APC binding, had no or only a modest effect. It is concluded that culturing U937 cells in the presence of APC caused down‐regulation of TF expression through the EPCR‐dependent mechanism, independent of whether induction was triggered by phorbol ester.