This study was to acquire recombinant protein of von Willebrand factor cleaving protease (ADAMTS13, a disintegrin and metalloprotease with a thromboSpondin type 1 motifs 13), for further studies on its biological function in thrombosis and hemostasis. We transfected the Hela cells with the plasmid pSecTag-ADAMTS13 by lipofectamine. A positive cell cloning was selected by hygromycin-B. The recombinant protein was purified with Ni-NTA agarose column by gradient imidazole. The purity and immune activity of purified products were identified with SDS-PAGE and Western blotting respectively. We also measured the enzymatic activity of recombinant protein (rADAMTS13) by GST-His two-site ELISA assay. The results showed that we successfully constructed Hela cells ADAMTS2-4 which expressed high level of rADAMTS13. We received about 5.8 mg recombinant protein in culture supernantants per liter purified with Ni-NTA column. The protein formed a main lane at the position of 190 kDa with SDS-PAGE and reacted with polyclonal antibody against ADAMTS13 by Western blotting. The amount of rADAMTS13 activity was 6.4 U/mL, according to the normal plasma defined as 1 U/mL. In conclusion, rADAMTS13 protein had high purity, immune activity and good enzymatic activity, which could establish the experimental foundation for further research on biological function and mechanism of this unique metalloprotease.
ADAM Proteins ; biosynthesis ; genetics ; metabolism ; ADAMTS13 Protein ; HeLa Cells ; Humans ; Recombinant Proteins ; biosynthesis ; genetics ; metabolism ; Transfection ; von Willebrand Factor ; metabolism

ADAMTS13, a plasma metalloprotease, specifically cleaves von Willebrand factor (vWF). Severe deficiency of plasma ADAMTS13 activity results in thrombotic thrombocytopenic purpura (TTP). In this review, the structure and function of ADAMTS13 protease and its relationship with TTP are summarized.
ADAM Proteins ; metabolism ; ADAMTS13 Protein ; Humans ; Purpura, Thrombotic Thrombocytopenic ; diagnosis ; pathology ; therapy

LR11, also known as SorLA or SORL1, is a type-I membrane protein from which a large extracellular part, soluble LR11 (sLR11), is released by proteolytic shedding on cleavage with a disintegrin and metalloproteinase 17 (ADAM17). A shedding mechanism is presumed to have a key role in the functions of LR11, but the evidence for this has not yet been demonstrated. Tetraspanin CD9 has been recently shown to regulate the ADAM17-mediated shedding of tumor necrosis factor-alpha and intercellular adhesion molecule-1 on the cell surface. Here, we investigated the role of CD9 on the shedding of LR11 in leukocytes. LR11 was not expressed in THP-1 monocytes, but it was expressed and released in phorbol 12-myristate 13-acetate (PMA)-induced THP-1 macrophages (PMA/THP-1). Confocal microscopy showed colocalization of LR11 and CD9 proteins on the cell surface of PMA/THP-1. Ectopic neo-expression of CD9 in CCRF-SB cells, which are LR11-positive and CD9-negative, reduced the amount of sLR11 released from the cells. In contrast, incubation of LR11-transfected THP-1 cells with neutralizing anti-CD9 monoclonal antibodies increased the amount of sLR11 released from the cells. Likewise, the PMA-stimulated release of sLR11 increased in THP-1 cells transfected with CD9-targeted shRNAs, which was negated by treatment with the metalloproteinase inhibitor GM6001. These results suggest that the tetraspanin CD9 modulates the ADAM17-mediated shedding of LR11 in various leukemia cell lines and that the association between LR11 and CD9 on the cell surface has an important role in the ADAM17-mediated shedding mechanism.
ADAM Proteins/*metabolism ; Antigens, CD9/genetics/*metabolism ; Cell Line, Tumor ; Humans ; LDL-Receptor Related Proteins/genetics/*metabolism ; Leukocytes/*metabolism ; Macrophages/metabolism ; Membrane Transport Proteins/genetics/*metabolism ; Proteolysis

OBJECTIVE: To explore the expression and distribution of a disintegrin and metalloprotease with thrombospondin motif (ADAMTS)-2 and transforming growth factor (TGF) -β1 in patients with or without cirrhosis, and to determine their relation. METHODS: The liver tissues from 16 patients with cirrhotic portal hypertensive and 8 patients with liver injury were collected in Wuhan General Hospital from March to June, 2010. Immunohistochemistry and Western blot were applied to detect the protein expression of ADAMTS-2 and TGF-β1. RESULTS: Immunohistochemistry showed that the expression of ADAMTS-2 and TGF-β1 was significantly higher in the cirrhotic tissues than that in normal tissues (P<0.05). Western blot also showed the expression of ADAMTS-2 and TGF-β1 in the cirrhosis tissues was significantly higher than that in normal tissues (P<0.05). There was a positive correlation between ADAMTS-2 and TGF-β1 (r=0.862, P<0.01). CONCLUSION ADAMTS-2 and TGF-β1 may have a synergistic reaction in promoting liver cirrhosis.
ADAM Proteins ; metabolism ; ADAMTS Proteins ; ADAMTS4 Protein ; Blotting, Western ; Humans ; Immunohistochemistry ; Liver ; metabolism ; pathology ; Liver Cirrhosis ; metabolism ; Procollagen N-Endopeptidase ; metabolism ; Transforming Growth Factor beta1 ; metabolism

PURPOSE: The in vitro study suggested that proline to serine polymorphism in codon 475 (C1423T) of the A Disintegrin and Metalloprotease with ThromboSpondin type 1 repeats-13 (ADAMTS-13) gene is related to reduced activity of ADAMTS- 13. In this study, the frequency of the Pro475Ser polymorphism in Koreans was studied and plasma ADAMTS-13 activity was measured to find out whether this polymorphism contributes to decreased ADAMTS-13 activity in Koreans. PATIENTS AND METHODS: The frequency of the C1423T allele of the ADAMTS13 gene was studied along with measuring plasma ADAMTS-13 activity in 250 healthy Korean individuals. RESULTS: The allele frequency of C1423T polymorphism was 4%, and the median activity of CT type was 107 (69-143)%, which was lower than in controls with the CC genotype [118 (48-197)%, (p=0.021)]. CONCLUSION: Therefore, the Pro475Ser polymorphism seems to be popular in the Korean population, and attenuates ADAMTS-13 plasma activity.
ADAM Proteins/blood/*genetics/metabolism ; Asian Continental Ancestry Group ; Fluorescence Resonance Energy Transfer ; Gene Frequency ; Genotype ; Humans ; *Polymorphism, Genetic

OBJECTIVETo investigate the susceptibility of von Willebrand factor (VWF) type 2A mutant A1500E to proteolysis by metalloprotease ADAMTS13 and to provide the direct supports for the pathogenesis of VWF mutation A1500E responsible for von Willebrand disease (VWD) type 2A.

METHODSRecombinant wild-type VWF (WT-VWF) and A1500E mutant VWF transiently expressed on transfected HeLa cell lines. Expression media were collected and concentrated, then cleaved directly by recombinant ADAMTS13 (rADAMTS13). Compared with WT-VWF, the susceptibility of A1500E mutant VWF to proteolysis by ADAMTS13 was analyzed using SDS-agarose gel VWF multimers analysis.

RESULTSIn vitro the expression of VWF:Ag in the supernatants of WT-VWF and A1500E mutant VWF were 1.10 U/ml and 0.78 U/ml, respectively, while VWF:Ag in cells lysates of A1500E mutant VWF was 90.6% of that of WT-VWF. The SDS-agarose gel VWF multimers analysis showed that there were no differences between WT-VWF and A1500E mutant VWF. The A1500E mutant VWF could be efficiently cleaved by ADAMTS13 under static condition without denaturants such as urea and guanidine HCl. VWF multimeric analysis showed that high and intermediate molecular weight multimers dramatically decreased while low molecular weight multimers obviously increased. Conversely, WT-VWF could not be cleaved by ADAMTS13 under the same condition.

CONCLUSIONThe A1500E mutation resulted in VWF more susceptible to ADAMTS13-dependent proteolysis, which belonged to VWD type 2A group 2 mutation.

ADAM Proteins ; genetics ; metabolism ; ADAMTS13 Protein ; Genotype ; HeLa Cells ; Humans ; Hydrolysis ; Mutation ; Recombinant Proteins ; genetics ; metabolism ; von Willebrand Disease, Type 2 ; genetics ; metabolism ; von Willebrand Factor ; genetics

BACKGROUNDIt has been found that cardiac protection afforded by ischemic preconditioning (IPC) is significantly reduced in the senescent myocardium. ADAMTS-1 (a disintesrin and metalloprotease with thrombospondin type 1 motifs) has been shown to inhibit angiogenesis in a variety of in vitro and in vivo assays. The aim of this study was to investigate the age-associated differences in ADAMTS-1 protein expression in rat myocardium after ischemic preconditioning.

METHODSSixty-four young (4 months) and old (24 months) male Sprague-Dawley rats were randomly assigned to an IPC group (40 rats) or a sham group (rats). A model of delayed IPC was induced and rats were sacrificed and myocardial samples were harvested from the ischemic-reperfused region for immunohistochemical detection of ADAMTS-1 at serial time points after IPC. A model of myocardial infarction was produced by ligation of the left anterior descending coronary artery in additional sets of young and old rats after sham or IPC procedures, then age-associated myocardial infarction survival after IPC was calculated.

RESULTSADAMTS-1 expression increased significantly in old rats compared to young rats (P < 0.05). The mean densities of ADAMTS-1 protein at 0, 6, 12, and 24 hours in young-IPC group after IPC were 0.05 ± 0.01, 0.13 ± 0.03, 0.16 ± 0.04, and 0.12 ± 0.03 vs. 0.07 ± 0.03, 0.20 ± 0.03, 0.24 ± 0.05, and 0.21 ± 0.04 in old-IPC group. IPC resulted in diminished survival rates (5/35 vs. 6/14, old-IPC group vs. old-sham group, P < 0.05), reduced left ventricular fractional shortening ((13.9 ± 2.8)% vs. (18.3 ± 2.3)%, P < 0.05) and increased the myocardial infarction size ((37.9 ± 3.2)% vs. (32.8 ± 5.1)%, P < 0.05) in the older rats.

CONCLUSIONSCardioprotection with IPC is attenuated in the older heart. ADAMTS-1 expression induced by IPC is greater in old rats. Over-expression of anti-angiogenic factors might be a potential mechanism behind reduced protection after IPC associated with aging.

ADAM Proteins ; metabolism ; ADAMTS1 Protein ; Aging ; metabolism ; physiology ; Animals ; Immunohistochemistry ; Ischemic Preconditioning, Myocardial ; Male ; Myocardial Infarction ; metabolism ; pathology ; Myocardium ; metabolism ; pathology ; Rats ; Rats, Sprague-Dawley

A disintegrin-metalloproteinase 28 (ADAM28) is one of important members of ADAM family, that is involved in various biological events including cell adhesion, proteolysis, growth and metastasis of solid tumors and hematological malignancies. Studies have shown that ADAM28 is highly expressed in several human tumors, such as lung, breast and bladder cancers, and chronic lymphocytic leukemia, and its tissue expression levels correlate with cancer metastasis. ADAM28-mediated cancer cell metastasis may be related with the cleavage of von Willebrand's factor (vWF), insulin-like growth factor binding protein-3 (IGFBP-3) and connective tissue growth factor (CTGF), as well as the promoting PSGL-1/P-selectin-mediated cell adhesion. This review summarizes the basic and translational aspects of ADAM28 biology that might stimulate the interest in ADAM28 research and discovery of novel ADAM28 targets, providing potential novel therapies for metastatic cancers.
ADAM Proteins ; metabolism ; Cell Adhesion ; Connective Tissue Growth Factor ; metabolism ; Humans ; Insulin-Like Growth Factor Binding Protein 3 ; metabolism ; Neoplasm Metastasis ; Neoplasms ; pathology ; von Willebrand Factor ; metabolism

Proteases are important molecules that are involved in many physiological and pathological processes of the human body, such as growth, apoptosis and metastasis cancer cells. They are potential targets in cancer diagnosis and biotherapy. In this study, we analyzed the salivary protease spectrum of patients with oral squamous cell carcinoma (OSCC), oral benign masses and chronic periodontitis, as well as that of health, using human protease array kits, enzyme-linked immunosorbent assay, western blot and immunofluorescence. The salivary protease spectrum was found to be associated with oral diseases. For example, the saliva of patients with OSCC contained increased numbers of proteases than those of other oral diseases and health. The levels of matrix metalloproteinase (MMP)-1, MMP-2, MMP-10, MMP-12, A disintegrin and metalloprotease (ADAM)9, A disintegrin and metalloprotease with thrombospondin type 13 motifs (ADAMST13), cathepsin V and kallikrein 5 in the saliva of patients with OSCC were significantly increased compared with those of other groups. Taking MMP-1, cathepsin V, kallikrein 5 and ADAM9 as biomarkers of OSCC, cutoff values were199, 11.34, 9.29 and 202.55 pg·mL, respectively. From the area under the curve, sensitivity and specificity, the combination of cathepsin V/kallikrein5/ADAM9 was an optimal biomarker for diagnosing OSCC. Thus, analysis of the salivary protease spectrum may be an innovative and cost-efficient approach to evaluating the health status of the oral cavity. Specifically, increases in cathepsin V, kallikrein 5 and ADAM9 may be useful biomarkers in the screening and diagnosis of OSCC.
ADAM Proteins ; Biomarkers, Tumor ; analysis ; Carcinoma, Squamous Cell ; diagnosis ; metabolism ; Humans ; Matrix Metalloproteinase 9 ; analysis ; Membrane Proteins ; Mouth Neoplasms ; diagnosis ; metabolism ; Saliva ; chemistry

BACKGROUNDA severe deficiency of ADAMTS13 activity contributes to the pathogenesis of thrombotic thrombocytopenic purpura (TTP). Measuring the activity of ADAMTS13 is helpful for the diagnosis of TTP and the prognostic monitor in TTP patients. Most available assays are cumbersome and costly, so not easily adapted to routine laboratories. ADAMTS13 cleaves von Willebrand factor (VWF) within the domain A2, located between domains A1 and A3. Therefore, specific assays for ADAMTS13 activity could be based on the different structures of VWF before and after the cleavage. Using this hypothesis we try to establish a new and simple method to determine ADAMTS13 activity.

METHODSFirst, plasma samples were exposed in denaturing condition to allow cleavage of VWF by ADAMTS13. Then, the ADAMTS13 activity was measured with two novel monoclonal antibodies, SZ-129 and SZ-125, which specifically recognize the VWF A1 and A3 domains by using a two-site sandwich ELISA. Compared with a residual-collagen binding assay (R-CBA), plasma ADAMTS13 activities in 161 samples were assessed, and the inhibitory activities of ADAMTS13 autoantibody in 24 TTP patients were determined. The relationship of these two assays was analyzed by linear correlation, and the sensitivity and specificity of the new assay was also evaluated.

RESULTSPlasma ADAMTS13 activities in normal people and TTP, acute myocardial infarction (AMI), and idiopathic thrombocytopenic purpura (ITP) patients determined by the new assay were (89.75 +/- 7.93)%, (17.63 +/- 18.71)%, (68.55 +/- 18.08)%, (85.83 +/- 9.84)%, respectively. Results were consistent with those of R-CBA, the squared correlation factor was 0.9183 of the two assays. The new assay can easily discriminate a TTP plasma sample from a non-TTP plasma sample (P < 0.01), and the coefficient of variation for the new assay was 6.17%. In 23 idiopathic TTP patients, the inhibitor activity of ADAMTS13 autoantibody ranged from 12% to 100%, while no inhibitory activity was detected in one hereditary TTP patient.

CONCLUSIONThis new and simple assay for ADAMTS13 activity could be used routinely in the clinic to determine the activity of ADAMTS13.

ADAM Proteins ; metabolism ; ADAMTS13 Protein ; Adolescent ; Adult ; Aged ; Female ; Humans ; Male ; Middle Aged ; Purpura, Thrombotic Thrombocytopenic ; metabolism ; Young Adult ; von Willebrand Factor ; metabolism