Histones Induce the Procoagulant Phenotype of Endothelial Cells through Tissue Factor Up-Regulation and Thrombomodulin Down-Regulation.
The high circulating levels of histones found in various thrombotic diseases may compromise the anticoagulant barrier of endothelial cells. We determined how histones affect endothelial procoagulant tissue factor (TF) and anticoagulant thrombomodulin (TM). Surface antigens, soluble forms, and mRNA levels of TF and TM were measured by flow cytometry, ELISA, and real-time RT-PCR, respectively. TF and TM activity were measured using procoagulant activity, thrombin generation, or chromogenic assays. Involvement of the toll-like receptor (TLR) was assessed using the neutralizing antibodies. Histones dose-dependently induced surface antigens, activity and mRNA levels of endothelial TF. Histone-treated endothelial cells significantly shortened the lag time and enhanced the endogenous thrombin potential of normal plasma, which was normalized by a TF neutralizing antibody. Histones induced phosphatidylserine and protein-disulfide isomerase expression in endothelial cells. Histones also reduced the surface antigen, activity, and mRNA levels of endothelial TM. Polysialic acid and heparin reversed the histone-induced TF up-regulation and TM down-regulation. Activated protein C did not affect the TF up-regulation, but interrupted TM down-regulation. TLR2, and TLR4 inhibitors partially blocked the TF up-regulation. Histones induced the endothelial procoagulant phenotype through TF up-regulation and TM down-regulation. The effects of histones were partly mediated by TLR2, TLR4. Strategies to inhibit the harmful effects of histones in endothelial cells may be required in order to prevent a thrombotic environment.
Department of Hemato-oncology, Healthcare Innovation Park, Seoul National University Bundang Hospital, Gyeonggi-do, South Korea.
Ji Eun
JE
Kim
Department of Laboratory Medicine and Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea.
Hyun Ju
HJ
Yoo
Department of Laboratory Medicine and Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea.
Ja Yoon
JY
Gu
Department of Laboratory Medicine and Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea.
Hyun Kyung
HK
Kim
D002460:Cell Line; D042783:Endothelial Cells / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D006657:Histones / Q000378:metabolism*; D006801:Humans; D010718:Phosphatidylserines / Q000378:metabolism; D019704:Protein Disulfide-Isomerases / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018180:Thrombomodulin / Q000235:genetics / Q000378:metabolism*; D013925:Thromboplastin / Q000235:genetics / Q000378:metabolism*; D051195:Toll-Like Receptor 2 / Q000378:metabolism; D051197:Toll-Like Receptor 4 / Q000378:metabolism
D006657:Histones; D010718:Phosphatidylserines; D012333:RNA, Messenger; C546931:THBD protein, human; C495342:TLR2 protein, human; C495345:TLR4 protein, human; D018180:Thrombomodulin; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D013925:Thromboplastin; D019704:Protein Disulfide-Isomerases