Tetranectin binds hepatocyte growth factor and tissue-type plasminogen activator
TL;DR: The study revealed that tetranectin did not interact with the kindred proteins: macrophage-stimulating protein, urokinase-type plasminogen activator and prothrombin, and a kinetic analysis of the tPA-catalysed plAsminogen activation was performed.
Abstract: In the search for new ligands for the plasminogen kringle 4 binding-protein tetranectin, it has been found by ligand blot analysis and ELISA that tetranectin specifically bound to the plasminogen-like hepatocyte growth factor and tissue-type plasminogen activator. The dissociation constants of these complexes were found to be within the same order of magnitude as the one for the plasminogen-tetranectin complex. The study also revealed that tetranectin did not interact with the kindred proteins: macrophage-stimulating protein, urokinase-type plasminogen activator and prothrombin. In order to examine the function of tetranectin, a kinetic analysis of the tPA-catalysed plasminogen activation was performed. The kinetic parameters of the tetranectin-stimulated enhancement of tPA were comparable to fibrinogen fragments, which are so far the best inducer of tPA-catalysed plasminogen activation. The enhanced activation was suggested to be caused by tetranectin's ability to bind and accumulate tPA in an active conformation.
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TL;DR: This review summarizes the structural composition of proteins and the current knowledge of underlying forces that lead proteins to lose their native structure and describes the molecular and cellular mechanisms that are associated with protein misfolding in disease.
Abstract: Proteins are essential elements for life. They are building blocks of all organisms and the operators of cellular functions. Humans produce a repertoire of at least 30,000 different proteins, each with a different role. Each protein has its own unique sequence and shape (native conformation) to fulfill its specific function. The appearance of incorrectly shaped (misfolded) proteins occurs on exposure to environmental changes. Protein misfolding and the subsequent aggregation is associated with various, often highly debilitating, diseases for which no sufficient cure is available yet. In the first part of this review we summarize the structural composition of proteins and the current knowledge of underlying forces that lead proteins to lose their native structure. In the second and third parts we describe the molecular and cellular mechanisms that are associated with protein misfolding in disease. Finally, in the last part we portray recent efforts to develop treatments for protein misfolding diseases.
205 citations
TL;DR: The results showed that the level of plasma peroxiredoxin II in patients with SARS is significantly high and could be secreted by T cells, indicating that active innate immune responses, along with the oxidation-associated injuries, may play a major role in the pathogenesis of SARS.
Abstract: We have investigated the plasma proteome by using 2D gel electrophoresis and MS from patients with severe acute respiratory syndrome (SARS). A complete proteomic analysis was performed on four patients with SARS in different time courses, and a total of 38 differential spots were selected for protein identification. Most of the proteins identified are acute phase proteins, and their presence represents the consequence of serial cascades initiated by SARS-coronavirus infection. There are several proteins that have never been identified in plasma before using 2D gel electrophoresis, among which peroxiredoxin II was chosen for further study by analyzing additional 20 plasma samples from patients with probable and suspected SARS and patients with fever, respectively. The results showed that the level of plasma peroxiredoxin II in patients with SARS is significantly high and could be secreted by T cells. Taken together, our findings indicate that active innate immune responses, along with the oxidation-associated injuries, may play a major role in the pathogenesis of SARS.
112 citations
TL;DR: Through integration of genome-wide methylation, gene and protein expression data in human primary chondrocytes, consistent molecular players in OA progression that replicated across independent datasets and that have translational potential are identified.
Abstract: Osteoarthritis (OA) is a common disease characterized by cartilage degeneration and joint remodeling. The underlying molecular changes underpinning disease progression are incompletely understood. We investigated genes and pathways that mark OA progression in isolated primary chondrocytes taken from paired intact versus degraded articular cartilage samples across 38 patients undergoing joint replacement surgery (discovery cohort: 12 knee OA, replication cohorts: 17 knee OA, 9 hip OA patients). We combined genome-wide DNA methylation, RNA sequencing, and quantitative proteomics data. We identified 49 genes differentially regulated between intact and degraded cartilage in at least two –omics levels, 16 of which have not previously been implicated in OA progression. Integrated pathway analysis implicated the involvement of extracellular matrix degradation, collagen catabolism and angiogenesis in disease progression. Using independent replication datasets, we showed that the direction of change is consistent for over 90% of differentially expressed genes and differentially methylated CpG probes. AQP1, COL1A1 and CLEC3B were significantly differentially regulated across all three –omics levels, confirming their differential expression in human disease. Through integration of genome-wide methylation, gene and protein expression data in human primary chondrocytes, we identified consistent molecular players in OA progression that replicated across independent datasets and that have translational potential.
89 citations
TL;DR: Results suggest that serum or saliva tetranectin may serve as a potential biomarker for metastatic OSCC, and other candidate serum biomarkers for OSCC included superoxide dismutase, ficolin 2, CD-5 antigen-like protein, RalA binding protein 1, plasma retinol-binding protein and transthyretin.
Abstract: Lymph node involvement is the most important predictor of survival rates in patients with oral squamous cell carcinoma (OSCC). A biomarker that can indicate lymph node metastasis would be valuable to classify patients with OSCC for optimal treatment. In this study, we have performed a serum proteomic analysis of OSCC using 2-D gel electrophoresis and liquid chromatography/tandem mass spectrometry. One of the down-regulated proteins in OSCC was identified as tetranectin, which is a protein encoded by the CLEC3B gene (C-type lectin domain family 3, member B). We further tested the protein level in serum and saliva from patients with lymph-node metastatic and primary OSCC. Tetranectin was found significantly under-expressed in both serum and saliva of metastatic OSCC compared to primary OSCC. Our results suggest that serum or saliva tetranectin may serve as a potential biomarker for metastatic OSCC. Other candidate serum biomarkers for OSCC included superoxide dismutase, ficolin 2, CD-5 antigen-like protein, RalA binding protein 1, plasma retinol-binding protein and transthyretin. Their clinical utility for OSCC detection remains to be further tested in cancer patients.
62 citations
Cites background from "Tetranectin binds hepatocyte growth..."
...The enhanced activation was suggested to be caused by tetranectin's ability to bind and accumulate tPA in an active conformation [53]....
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Journal Article•
TL;DR: Preoperative plasma suPAR level was of no prognostic value in this cohort of Danish stage III OC patients and the prognostic significance of suPAR was also compared to two biochemical markers; cancer antigen 125 and tetranectin.
Abstract: The level of the urokinase plasminogen activator receptor (uPAR) is elevated in tumor tissue from several forms of cancer. uPAR is shed from the cell surface and the soluble form, soluble urokinase plasminogen activator receptor (suPAR), has been detected in several body fluids. High plasma levels of suPAR in patients with colorectal cancer and high serum levels of suPAR in patients with recurrent metastatic breast cancer have been associated with poor prognosis. In patients with ovarian cancer (OC) it has been shown that the level of suPAR is very high in ascites and cystic fluid and that high serum levels of suPAR were associated with shorter survival of the patients. We evaluated suPAR preoperatively in plasma from primary OC stage III patients and tested for association with prognosis. The prognostic significance of suPAR was also compared to two biochemical markers; cancer antigen 125 (CA125) and tetranectin (TN).No significant differences were found between patients who died of OC compared to patients still alive regarding median plasma suPAR levels (p=0.62) and median serum CA125 levels (p=0.26). In contrast, a significant difference was found between dead and alive OC patients for the median serum TN level (p<0.0001). Dividing the patients into two groups, corresponding to preoperative plasma suPAR levels below or equal to 2.0 ng/ml and higher than 2.0 ng/ml, no significant difference in survival was found between the two groups (p=0.49). When different cut-off levels of plasma suPAR were considered (2.74 ng/ml, 3.25 ng/ml and 4.18 ng/ml), no significant differences in survival could be detected (p=0.58, p=0.68 and p=0.05). Multivariate Cox regression analysis showed that the only independent prognostic factors were radicality after primary surgery (RH=5.34; 95% CI, 2.34-12.20; p<0.0001) and preoperative serum TN (RH=0.69, 95% CI, 0.57-0.82; p<0.0001), whereas plasma suPAR (4.18 ng/ml), age, histological type of tumour and serum CA125 had no independent prognostic value. In conclusion, preoperative plasma suPAR level was of no prognostic value in this cohort of Danish stage III OC patients. Ovarian cancer (OC) is the most lethal of the gynaecologic malignancies, ranking the fifth most frequent female cancer type and the fourth most frequent cause of death from cancer among women in Denmark (1). Every year, nearly 600 new cases appear, yielding an age-standardized incidence rate of 13.2 per 100,000 (1997) (2, 3), which is among the highest incidence rates observed worldwide. Published five-year survival rates for OC patients range from more than 80 percent for FIGO (The International Federation of Gynaecology and Obstetrics staging) stage I OC to less than 20 percent for stage III and IV OC's (4, 5). uPAR (urokinase plasminogen activator receptor) is a cell surface glycoprotein with a molecular mass of 55-60 kd, composed of three homologous domains of approximately 90 amino acids each (6-8). The protein is, through the
37 citations
References
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Journal Article•
TL;DR: It is reported that both urokinase-type plasminogen activator and tissue-type Plasminogens activator can cleave single-chain hepatocyte growth factor, generating two- Chain hepatocytes growth factor.
Abstract: Hepatocyte growth factor, also known as scatter factor, is a complete mitogen for hepatocytes that bears sequence and structural homology with plasminogen. Because it exists in both a mitogenically inactive single-chain form and an active two-chain form, we were interested in determining whether plasminogen activators could properly cleave single-chain hepatocyte growth factor to generate active two-chain hepatocyte growth factor. Herein we report that both urokinase-type plasminogen activator and tissue-type plasminogen activator can cleave single-chain hepatocyte growth factor, generating two-chain hepatocyte growth factor. When equal quantities of plasminogen activator-treated and activator-untreated hepatocyte growth factor are compared in serum-free in vitro bioassays, the treated hepatocyte growth factor is mitotically more active. Also, urokinase-type plasminogen activator was inactive against hepatocyte growth factor molecules with a mutated cleavage site. This suggests that urokinase-type and tissue-type plasminogen activator may be natural biological regulators of hepatocyte growth factor. Because the active form of hepatocyte growth factor is a powerful stimulator of DNA synthesis and cell motility, these findings may be relevant in understanding the role of plasminogen activators in the biology of cancer invasion and metastasis.
392 citations
TL;DR: It is concluded that HGF activator is present in plasma as an inactiveZymogen and that the zymogen is activated by the cleavage of the bond between Arg407 and Ile408 by thrombin.
212 citations
TL;DR: A tetrameric protein composed of four subunits, that is dissociated by 1% sodium dodecyl sulphate, is suggested to be a novel plasma protein tentatively called 'tetranectin'.
Abstract: Purification of alpha 2-plasmin inhibitor (alpha 2PI) from human plasma by affinity chromatography on plasminogen-Sepharose resulted in copurification of a contaminating protein with Mr 17,000 as judged by sodium dodecyl sulphate/polyacrylamide gel electrophoresis. This contaminating protein could not be removed from the purified alpha 2-PI preparation by several types of gel chromatography applied. The use of the kringle 1-3 part of plasminogen, K(1 + 2 + 3), bound to Sepharose for affinity chromatography, instead of plasminogen-Sepharose, resulted in an alpha 2PI preparation without this contaminant. The contaminating protein was found to interact specifically with the kringle 4 part of plasminogen (K4) and not with K(1 + 2 + 3) or miniplasminogen. The K4-binding protein was purified by ammonium sulphate precipitation, affinity chromatography on K4-Sepharose, ion-exchange chromatography and gel filtration on AcA 34. The relative molecular mass of the protein (Mr 68 000) was estimated by gel filtration. This suggests a tetrameric protein composed of four subunits (Mr 17,000), that are dissociated by 1% sodium dodecyl sulphate. Dissociation into subunits was also demonstrated by gel filtration in the presence of 6 M guanidine hydrochloride. A specific antibody was raised in rabbits against the purified protein and this antibody was shown not to react with any known fibrinolytic components. The pI of the K4-binding protein was found to be 5.8. The first three N-terminal amino acids were determined to be Glu-Pro-Pro. The concentration of the protein in plasma was estimated to be 0.20 +/- 0.03 microM (15 +/- 2 mg/l). The electrophoretic mobility of the K4-binding protein was shown by crossed immunoelectrophoresis to be influenced by the presence of Ca2+, EDTA and heparin. The protein was found to enhance plasminogen activation catalyzed by tissue-type plasminogen activator (t-PA) in the presence of poly(D-lysine). The protein appeared to be a novel plasma protein tentatively called 'tetranectin'.
194 citations
TL;DR: A potential role for tetranectin as a bone matrix protein expressed in time and space coincident with mineralization in vivo and in vitro is established.
Abstract: Tetranectin is a protein shared by the blood and the extracellular matrix. Tetranectin is composed of four identical, noncovalently bound polypeptides each with a molecular mass of approximately 21 kD. There is some evidence that tetranectin may be involved in fibrinolysis and proteolysis during tissue remodeling, but its precise biological function is not known. Tetranectin is enriched in the cartilage of the shark, but the gene expression pattern in the mammalian skeletal system has not been determined. In the present study we have examined the expression pattern and putative function of tetranectin during osteogenesis. In the newborn mouse, strong tetranectin immunoreactivity was found in the newly formed woven bone around the cartilage anlage in the future bone marrow and along the periosteum forming the cortex. No tetranectin immunoreactivity was found in the proliferating and hypertrophic cartilage or in the surrounding skeletal muscle. Using an in vitro mineralizing system, we examined osteoblastic cells at different times during their growth and differentiation. Tetranectin mRNA appeared in the cultured osteoblastic cells in parallel with mineralization, in a pattern similar to that of bone sialoprotein, which is regarded as one of the late bone differentiation markers. To explore the putative biological role of tetranectin in osteogenesis we established stably transfected cell lines (PC12-tet) overexpressing recombinant tetranectin as evidenced by Northern and Western blot analysis and immunoprecipitation. Both control PC12 cells and PC12-tet cells injected into nude mice produced tumors containing bone material, as evidenced by von Kossa staining for calcium and immunostaining with bone sialoprotein and alkaline phosphatase antiserum. Nude mice tumors established from PC12-tet cells contained approximately fivefold more bone material than those produced by the untransfected PC12 cell line or by the PC12 cells transfected with the expression vector with no insert (Mann Whitney rank sum test, p < 0.01), supporting the notion that tetranectin may play an important direct and/or indirect role during osteogenesis. In conclusion, we have established a potential role for tetranectin as a bone matrix protein expressed in time and space coincident with mineralization in vivo and in vitro.
107 citations
TL;DR: The trimerization of tetranectin as well as the fixation of the CRDs relative to the helices in the coiled coil indicate a demand for high specificity in the recognition and binding of ligands.
96 citations