A novel flow‐based assay reveals discrepancies in ADAMTS‐13 inhibitor assessment as compared with a conventional clinical static assay

Grillberger, Rana; Gruber, Bernhard; Skalicky, Susanna; Schrenk, Gerald; Knöbl, Paul; Plaimauer, Barbara; Turecek, Peter L.; Scheiflinger, F.; Rottensteiner, Hanspeter

doi:10.1111/jth.12653

Cited by 4 publications

(4 citation statements)

References 40 publications

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“…Thus far, ADAMTS13 has been shown to be susceptible to proteolysis by thrombin and furin, as well as inhibitory autoantibodies (20)(21)(22)(23)(24). These findings, taken together with the results of the present study, suggest that TIMPs have no role to play in its regulation.…”

Section: Discussionsupporting

confidence: 65%

ADAMTS13 and 15 are not regulated by the full length and N-terminal domain forms of TIMP-1, -2, -3 and -4

2015

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Abstract.A disintegrin and metalloproteinase with thombospondin motifs (ADAMTS) 13 and 15 are secreted zinc proteinases involved in the turnover of von Willebrand factor and cancer suppression. In the present study, ADAMTS13 and 15 were subjected to inhibition studies with the full-length and N-terminal domain forms of tissue inhibitor of metalloproteinases (TIMPs)-1 to -4. TIMPs have no ability to inhibit the ADAMTS proteinases in the full-length or N-terminal domain form. While ADAMTS13 is also not sensitive to the hydroxamate inhibitors, batimastat and ilomastat, ADAMTS15 can be effectively inhibited by batimastat (K i app 299 nM). In conclusion, the present results indicate that TIMPs are not the regulators of these two ADAMTS proteinases. IntroductionA disintegrin and metalloproteinase with thombospondin motifs (ADAMTSs) are secreted members of the zinc-dependent metalloproteinases that contain one or more thrombospondin type 1 repeats (TSP1) as the ancillary domains. There are ≥26 ADAMTS proteinases identified thus far; however, not all of them are known to possess enzymatic activity. The ADAMTS proteinases are important regulators of cellular events, as the enzymes have been shown to exhibit a vast array of activities, including cleavage of pro-collagen and von Willebrand factor (VWF), tumor suppression and proteolysis activities associated with arthritis, morphogenesis, angiogenesis and even ovulation [as reviewed previously (1,2)].Also known as the VWF-cleaving protease, ADAMTS13 is noted for its ability in cleaving and reducing the size of the ultra-large (UL) form of the VWF. Reduction in ADAMTS13 activity from either hereditary or acquired deficiency causes accumulation of UL-VWF multimers, platelet aggregation and arterial thrombosis that leads to fatal thrombotic thrombocytopenic purpura [as reviewed previously (1,3)]. By contrast, ADAMTS15 is a potential tumor suppressor. Only a limited number of in-depth investigations have been carried out on the enzyme; however, expression and profiling studies have shown that the ADAMTS15 gene is genetically inactivated in colon cancer and breast carcinoma, although the exact role of the enzyme remains to be delineated (4,5).Structure-wise, ADAMTS13 and 15 share a common domain organization with the other members of the ADAMTS proteinases. At the N-terminal of their polypeptides is a pro-peptide and a metalloproteinase domain in which the catalytic activity of the proteinases resides. Succeeding the metalloproteinase domain is a disintegrin-like domain followed by the first TSP1, a cysteine-rich domain, a spacer domain and 7 more TSP1 repeats and 2 CUB domains. As with the members of the matrix metalloproteinase (MMP) and ADAM proteinases, the metalloproteinase domain of ADAMTS13 bears the typical hallmarks of the reprolysin or adamalysin proteinases, namely a zinc-binding motif 'HExxHxxGxxH' that is essential for substrate turnover. Notably, human ADAMTS15 has a slightly modified zinc-binding motif, 'HExxNxxGxxH,' instead of the usual conserved sequence (2,6,...

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Section: Discussionsupporting

confidence: 65%

ADAMTS13 and 15 are not regulated by the full length and N-terminal domain forms of TIMP-1, -2, -3 and -4

2015

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“…At 6 h and 24 h post-stimulation, HSCs and endothelial cells expressed less ADAMTS13 mRNA. However, ADAMTS13 mRNA deficiency should not significantly influence proteolysis of circulating or endothelium-bound VWF because an increase in shear stress during administration of the vasoconstrictors results in the exposure of selective epitopes of VWF, thereby enhancing proteolysis by residual ADAMTS13 as a compensatory event (53). In our study, ADAMTS13 transcript levels and proteolytic activity are downregulated by vasopressin in vitro.…”

Section: Discussionmentioning

confidence: 55%

Preserved Expression of mRNA Coding von Willebrand Factor-Cleaving Protease ADAMTS13 by Selenite and Activated Protein C

Ekaney

Bockmeyer

Soßdorf

et al. 2015

Mol Med

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“…Another unknown factor potentially affecting the effi cacy of rhADAMTS13 in the acquired TTP setting is the recently shown variance in inhibitor capacity of anti-ADAMTS13 antibodies in plasma purifi ed from different patients. Antibody samples with the same inhibitory capacity as measured by Bethesda assay showed vastly different inhibitory kinetics under fl ow conditions [ 35 ].…”

Section: Potential For Treatment Of Acquired Ttp With Recombinantmentioning

confidence: 99%

Potential Clinical Use of Recombinant Human ADAMTS13

2015

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A novel flow‐based assay reveals discrepancies in ADAMTS‐13 inhibitor assessment as compared with a conventional clinical static assay

Cited by 4 publications

References 40 publications

ADAMTS13 and 15 are not regulated by the full length and N-terminal domain forms of TIMP-1, -2, -3 and -4

ADAMTS13 and 15 are not regulated by the full length and N-terminal domain forms of TIMP-1, -2, -3 and -4

Preserved Expression of mRNA Coding von Willebrand Factor-Cleaving Protease ADAMTS13 by Selenite and Activated Protein C

Potential Clinical Use of Recombinant Human ADAMTS13

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