ADAMTS13 is expressed in hepatic stellate cells.
ADAMTS13 is a circulating zinc metalloprotease that cleaves the hemostatic glycoprotein von Willebrand factor (VWF) in a shear-dependent manner. Deficiency in ADAMTS13, owing to genetic mutations or autoimmune inhibitors, causes thrombotic thrombocytopenic purpura (TPP). Northern blot analysis has shown that ADAMTS13 is expressed primarily in the liver. By using real-time RT-PCR, we confirmed that in mice the liver had the highest level of the ADAMTS13 transcript. To identify the liver cell-type-specific origin of ADAMTS13, we used in situ hybridization techniques to investigate the pattern of ADAMTS13 expression in the liver; analyzed the ADAMTS13 proteolytic activity in the culture media of fractionated liver cells; and confirmed ADAMTS13 expression with RT-PCR analysis and cloning of the mouse ADAMTS13 gene. The results revealed that ADAMTS13 was expressed primarily in cell fractions enriched in hepatic stellate cells. The mouse ADAMTS13 cloned from primary hepatic stellate cells was similar to its human counterpart in digesting VWF and was susceptible to suppression by EDTA or the IgG inhibitors of patients with TTP. Since hepatic stellate cells are believed to play a major role in the development of hepatic fibrosis and cirrhosis, the identification of the liver cell-type expressing ADAMTS13 will have important implications for understanding pathophysiological mechanisms regulating ADAMTS13 expression.
Zhou
Wenhua
W
Division of Hematology, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY 10467, USA.
Inada
Mari
M
Lee
Tai-Ping
TP
Benten
Daniel
D
Lyubsky
Sergey
S
Bouhassira
Eric E
EE
Gupta
Sanjeev
S
Tsai
Han-Mou
HM
D000071120:ADAMTS13 Protein; D000818:Animals; D002460:Cell Line; D002478:Cells, Cultured; D003001:Cloning, Molecular; D003470:Culture Media; D015971:Gene Expression Regulation, Enzymologic; D017403:In Situ Hybridization; D008099:Liver / Q000166:cytology* / Q000201:enzymology*; D008666:Metalloendopeptidases / Q000235:genetics*; D051379:Mice; D008815:Mice, Inbred Strains; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic
D003470:Culture Media; C502939:ADAMTS13 protein, mouse; D008666:Metalloendopeptidases; D000071120:ADAMTS13 Protein