Human endothelial cells synthesize and release ADAMTS-13.
Hepatic stellate cells have been considered to be a primary source for human plasma ADAMTS-13, the von Willebrand factor (VWF)-cleaving metalloprotease. In this study, ADAMTS-13 antigen was detected by immunofluorescence in both venous (HUVECs) and arterial endothelial cells (HUAECs) using both polyclonal antibodies made against peptides found in various domains of human ADAMTS-13, as well as by a monoclonal antibody against the ADAMTS-13 metalloprotease domain. ADAMTS-13 antigen had an intra-cellular distribution in endothelial cells distinct from the Weibel-Palade body location of VWF, and was released from the cells during 48 h in culture. The mRNA for ADAMTS13 was detected in HUVECs and HUAECs using reverse transcription-polymerase chain reaction (RT-PCR), indicating that the enzyme is synthesized in these cells. The ADAMTS-13 protein was immunoprecipitated from HUVECs and had an approximate M(r) of 170 kDa, similar to the molecular mass of recombinant ADAMTS-13. The ADAMTS-13 in HUVEC and HUAEC lysates had enzymatic activity using both static and flow assays. We conclude that ADAMTS-13 is synthesized in human endothelial cells, and released constitutively. The vast number of endothelial cells in the body may be an important source of ADAMTS-13.
Turner
N
N
Department of Bioengineering, Rice University, Houston, TX 77005, USA.
Nolasco
L
L
Tao
Z
Z
Dong
J-F
JF
Moake
J
J
D051722:ADAM Proteins / Q000096:biosynthesis* / Q000235:genetics; D000071120:ADAMTS13 Protein; D000818:Animals; D000911:Antibodies, Monoclonal; D016466:CHO Cells; D002478:Cells, Cultured; D006224:Cricetinae; D003412:Cricetulus; D042783:Endothelial Cells / Q000201:enzymology*; D005455:Fluorescent Antibody Technique; D015870:Gene Expression; D006801:Humans; D012333:RNA, Messenger / Q000096:biosynthesis; D014162:Transfection; D014841:von Willebrand Factor / Q000276:immunology / Q000378:metabolism
D000911:Antibodies, Monoclonal; D012333:RNA, Messenger; D014841:von Willebrand Factor; D051722:ADAM Proteins; D000071120:ADAMTS13 Protein; C099604:ADAMTS13 protein, human