Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:3.4.21.4 (trypsin)
42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The synthesis and turnover of glycosaminoglycans (GAGs) in different fractions of cultured feline retinal pigment epithelium (RPE) were characterized. In one method of fractionation, trypsin was used to separate the extracellular components (referred to as trypsin-soluble glycocalyx) from the intracellular components. As a second method, the basal extracellular matrix (basal ECM) was separated from the rest of the GAGs (cell-associated GAGs) by extracting the cell layer with NH4OH. The incorporation of 35SO4 into cetylpyridinium chloride-precipitable GAGs in the cell-associated and the intracellular fractions increased throughout the labeling period, while in the trypsin-soluble glycocalyx and the basal ECM incorporation approached a maximum. While heparan sulfate was the predominant GAG in all compartments, most was located extracellularly. The majority of dermatan sulfate was localized in the intracellular fraction. GAGs in the trypsin-soluble glycocalyx exhibited a rapid rate of turnover, while GAGs in the intracellular compartment and basal ECM turned over much more slowly. Ascorbic acid increased the incorporation of 35SO4 into ECM chondroitin sulfate/dermatan sulfate, but not heparan sulfate, on a per cell basis. Cycloheximide reduced incorporation of 35SO4-GAGs into both the cell-associated compartment and the basal ECM. In contrast, monensin caused a reduction in basal ECM GAGs while increasing the GAGs in the cell-associated compartment. The intracellular accumulation of GAGs and resultant pathology in alpha-L-iduronidase (alpha-L-id)-deficient RPE indicated that this pathway for the intracellular degradation of GAGs is important in normal RPE function. However, the turnover of GAGs in the trypsin-soluble glycocalyx was not affected by deficient alpha-L-id activity or by the subsequent intracellular accumulation of GAGs. Therefore, normal lysosomal activity in the RPE is not a prerequisite for maintaining the rate of extracellular GAG turnover within normal limits.
...
PMID:Retinal pigment epithelial glycosaminoglycan metabolism: intracellular versus extracellular pathways. In vitro studies in normal and diseased cells. 250 68

The behaviour in vivo of tight and loose variants of murine melanoma cells is further characterized. In vitro clonal morphology is reproduced on a variety of substrates. Results suggest that repeated selection of loose cells can co-select for cells with high metastatic and colonization potentials. Measurement of cell motility shows that 1G3 (loose) cells are more motile than 1G8 (tight) which are restricted to movements within clonal boundaries. Studies of adhesive properties show that loose cells are more easily detached from the substrate with trypsin or EDTA and that both cell lines attach more quickly to monolayers of loose cells than to tight ones. No gross differences are found either in attachment rates to plastic and ECM or in aggregation and disaggregation rates. Analysis of the cell surface has not revealed any differences between 1G8 and 1G3 in the sialylation of terminal galactose and N-acetylgalactosamine residues or in neuraminidase releasable sialic acid. The binding patterns of iodinated lectins to SDS-PAGE separated proteins are similar for both lines except for one 85/90 KD protein which is more abundant in 1G3 than 1G8 cells after neuraminidase treatment. The results show enhanced differences in metastatic potential of tight and loose clones after selective cloning and that there may be important differences in motility and cell-substrate interactions.
...
PMID:Morphological and metastatic murine melanoma variants: motility, adhesiveness, cell surface and in vivo properties. 342 20

Primary cultures of confluent human endothelial cells (ECM) were grown in media containing the major lipoproteins (LP) and lipoprotein deficient serum (LDS). The release of 6-keto-PGF1 alpha, von Willebrand factor (VIII RAg) and apolipoproteins (apo) A-I and A-II were investigated by radioimmunoassay. The cell-associated VIII RAg, apo A-I and apo A-II were also confirmed by fluorescein antibodies, and the synthesis of the apolipoproteins was examined by incorporation of [3H]leucine. Apo A-I and apo A-II were located and synthesized in ECM, yet only apo A-I was released into the medium. Very low density (VLDL) and low density lipoproteins (LDL) in concentrations of 50-600 micrograms/ml stimulated release of apo A-I. Stimulation of ECM for 5 min with thrombin (T) or arachidonic acid (A) did not induce apo A-I release. VIII RAg was always released into the media from ECM. The release was not affected by the lipoproteins. VIII RAg was also localized on the cell surface (VIII RAgC) and approximately 80% was released by trypsin. LDL stimulated the occurrence of factor VIII RAg on the cell surface. 6-Keto PGF1 alpha was always released into the medium and the production was stimulated by T and AA. The main lipoproteins (50-600 micrograms/ml) and apo A-I and A-II did not affect the release of 6-keto-PGF1 alpha. This study shows that endothelial cells synthesize and release proteins important for thrombogenesis and atherosclerosis. The release of apolipoproteins A-I was stimulated by VLDL and LDL, and the concentration of cell-related factor VIII RAg was stimulated by LDL.
...
PMID:The effect of lipoproteins on the synthesis of prostacyclin, von Willebrand factor and apolipoproteins A-I and A-II in cultured human endothelial cells. 642 92

Adult human corneal endothelial cells (HCEC) have extremely low turnover rates but undergo rapid division in vitro when stimulated with soluble growth factors. We have investigated the role played by FGF2 and TGF beta-1 in the regulation of HCEC growth stimulation. HCEC from donors who were over 30 years old were cultured and experiments performed on cultures between the 2nd and the 6th passage in the presence of 5% NCS. Cell counts revealed a maximal stimulation of 2.1x for FGF2 and 1.9x for TGF beta-1 compared to control cultures. When both factors were added, a synergistic effect was noticed with a maximal stimulation of the proliferation rate of 4.5x over controls. In addition, endogenous FGF2 produced by HCEC was quantitated in a sensitive EIA assay. After 5 days in culture, 10(6) cells contained 150 ng FGF2 and 35 ng was extracted from trypsin-digested ECM. Two molar NaCl washes of ECM released 15.6 ng FGF2, which induced a slight mitogenic activity (1.5x over control) in HCEC cultures, which was partially inhibited by an anti-FGF2 antibody. Northern blot analysis of HCEC extracts revealed the presence of FGF receptors R1 and R2 mRNA. The bioactive FGFRs were demonstrated by the toxic effect of a mitotoxin FGF2-SAP. These results suggest that FGF2 could participate in the autocrine regulation of HCEC proliferation and survival. The synergy between exogenously added FGF2 and TGF beta demonstrates that a combination of different growth factors may be important to stimulate proliferation of these cells in vivo.
...
PMID:The role of exogenous/endogenous basic fibroblast growth factor (FGF2) and transforming growth factor beta (TGF beta-1) on human corneal endothelial cells proliferation in vitro. 766 41

Conditioned medium (CM), collected from 7 and 14 days-old chick embryo skin fibroblasts and added to the same cells, increases glycosaminoglycans (GAG) intra- and extracellular accumulation. The factors responsible for GAG enhancement are TGF alpha and TGF beta because they are trypsin and dithiothreitol sensitive, stable or enhanced by heat and transient acidification. Moreover, Sephadex G-75 fractions of CM active on GAG synthesis contain, when analysed on SDS-polyacrylamide gel electrophoresis, two bands that comigrate with TGF alpha and TGF beta and induce NRK cells clone 49F to form large colonies of mean size > 8.000 microns 2 in soft agar. Since both the factors must be present to induce the formation of large colonies we come to the conclusion that CM contains TGF alpha and TGF beta. The two growth factors have different effects on the accumulation of individual classes of GAG in the ECM. In particular, TGF beta stimulates a marked increase of CS and DS, TGF alpha of HA and DS in the medium. The contemporaneous addition of TGF alpha and TGF beta to 7 days-old fibroblasts produces a pattern of GAG response similar to CM. These embryonic fibroblasts may control their own GAG synthesis and secretion through autocrine TGF alpha and beta activity.
...
PMID:Embryonic skin fibroblasts release TGF alpha and TGF beta able to influence synthesis and secretion of GAG. 832 81

Hepatocyte growth factor (HGF) promotes the growth not only of hepatocytes but also of several other types of cells such as cytotrophoblasts and endothelial cells. Recent studies have revealed that HGF is trapped in the extracellular (ECM) matrix through heparan sulphate in vivo, thereby acting as a mitogen for hepatocytes in cooperation with heparan sulphate. In this study, we detected HGF protein in chorionic tissue and placental tissue extracts, and found that HGF and heparan sulphate were co-distributed in the endothelial basement membrane and trophoblast basement membrane on immunohistochemical examination. The rates of DNA synthesis in primary cultured cytotrophoblasts and human umbilical vein endothelial cells (HUVEC) cultured on HGF-bound Matrigeltrade mark were 6-8 times those of control cytotrophoblasts and HUVEC. When Matrigeltrade mark dishes were pretreated with heparinase and heparitinase prior to binding of HGF, stimulation of DNA synthesis was markedly decreased. A considerable decrease in stimulation of DNA synthesis was observed following washing of HGF-bound Matrigeltrade mark with 1 m acetic acid, 1 m NaCl and 0.1 per cent trypsin, but not following treatment with chondroitinase ABC. These observations suggest that HGF can be trapped in ECM in vivo, thereby acting as a mitogen for cytotrophoblasts and placental vein endothelial cells in cooperation with heparan sulphate.
...
PMID:Stimulation of DNA synthesis in trophoblasts and human umbilical vein endothelial cells by hepatocyte growth factor bound to extracellular matrix. 1052 23

The bacterial surfaces of enterococci are not uniform. This fact is confirmed by several studies and by our results when great differences between individual strains with regard to their cell surface hydrophobicity, binding of eight ECM (extracellular matrix) molecules immobilized on latex beads and four selected ECM molecules in microtiter plates were observed. The strains expressing high binding of ECM molecules (e.g., HJ 18, HJ 23, HJ 24, HJ 26, HJ 28, HJ 36, etc.) were found among Enterococcus faecalis and E. faecium by PAA (particle agglutination assay). On the other hand, weak ECM binders (e.g., HJ 21, HJ 32, HJ 34, HJ 38, HJ 39, HJ 42, HJ 43) were also found. A direct correlation was found between porcine mucin and fetuin binding ability of eight selected strains tested in microtiter plates and by PAA. Moreover, the influence of tunicamycin treatment was different because significant (P < 0.001) blocking effect of tunicamycin was observed with two selected strains (HJ 26 and HJ 36), whereas two strains (HJ 18 and HJ 22) were not significantly affected in their fetuin binding. The treatment of six enterococcal strains with proteolytic enzymes, pronase P, and trypsin, and with sodium metaperiodate also significantly (P < 0.001) decreased their fetuin binding. This suggests that both protein and carbohydrate moieties are involved in the binding of immobilized fetuin. However, the influence of these chemicals on the fetuin binding by individual strains was different.
...
PMID:Binding of extracellular matrix molecules by enterococci. 1273 51

The multidisciplinary research of tissue engineering utilizes biodegradable or decellularized scaffolds with autologous cell seeding. Objective of this study was to investigate the impact of different decellularization protocols on extracellular matrix integrity of xenogeneic tissue by means of multiphoton femtosecond laser scanning microscopy, biochemical and histological analysis. Pulmonary valves were dissected from porcine hearts and placed in a solution of trypsin-EDTA and incubated at 37 degrees C for either 5, 8, or 24 h, followed by a 24 h PBS washing. Native and decellularized valves were processed for histology, DNA, cell proliferation, matrix proteins and biomechanical testing. Multiphoton NIR laser microscopy has been applied for high-resolution 3D imaging of collagen and elastin. Distinct differences in several ECM components following decellularization time were observed. Total GAG contents decreased in a time-dependent manner, with o-sulfated GAGs being more susceptible to degradation than n-sulfated GAGs. Efficiency of insoluble collagen extraction increased proportionally with decellularization time, suggesting ECM-integrity may be compromised with prolonged incubation. Biomechanical testing revealed a gradual weakening of mechanical strength with increased decellularization time. The enzymatic decellularization process of heart valves revealed a time-dependent loss of cells, ECM components and biomechanical strength. In order to avoid any immune response a thorough decellularization of 24 h remains mandatory.
...
PMID:Impact of decellularization of xenogeneic tissue on extracellular matrix integrity for tissue engineering of heart valves. 1457 75

Trypsinogen/trypsin is one of the major serine proteases and is produced by pancreatic acinar cells. Tumor-associated trypsinogen (TAT) has been reported to be produced by several cancer cell lines. The biological roles and activation mechanisms of both TAT and pancreatic acinar trypsinogen (PAT) have not been elucidated in the context of cancer extension, in particular at the stage of invasion and metastasis. In this study, we investigate the roles played by PAT and TAT in pancreatic cancer invasion. In addition, we determined their mechanisms of activation and identified a trypsinogen activity-stimulating factor (TASF) produced by pancreatic cancer cells. TAT expression and high TAT activity were associated with high invasive and liver metastatic potential in SW1990 and CAPAN-2 cells. Moreover, a trypsinogen activating effect and activity prolonging effect was observed in a mixture of these supernatants with trypsinogen. These cells revealed significantly enhanced invasiveness upon invasion assay and in the presence of PAT. TAT and PAT were activated by TASF, active u-PA, produced by pancreatic cancer cells. Activated TAT and PAT can degrade not only ECM proteins but they can also activate other latent proteases. This ECM-protease-network may form a vicious cycle, thereby promoting tumor cell invasion.
...
PMID:Identification of a trypsinogen activity stimulating factor produced by pancreatic cancer cells: its role in tumor invasion and metastasis. 1461 60

A survey of the available biological data on tryptase inhibitors suggests that there is considerable interest in tryptase as a therapeutic target particularly for the treatment of allergic asthma and inflammatory disorders. This interest was driven primarily by data from studies carried out on the cellular and in vivo actions of this serine protease over the past decade, all of which have suggested a pro-inflammatory role for tryptase. Tryptase beta is the form of interest in allergic asthma and the data from numerous studies have shown that tryptase cannot only contribute to airway bronchoconstriction and hyperresponsiveness, but may have a key role in fibrosis and ECM turnover, hallmarks of the remodeling process. Hence, inhibitors of tryptase have the potential to make an impact on fibrosis and airway wall remodelling. However, few studies, if any, have been carried out to determine the effect of tryptase inhibitors on airway remodeling and this is an area that warrants further investigation with the appropriate models because the eventual positioning of tryptase inhibitors in asthma therapy will be strengthened by data supporting an impact on airway remodeling in addition to effects on bronchial hyperresponsiveness. This review has focused on tryptase inhibitors in the pipeline and it is clear that with a few exceptions, the majority of these compounds are targeted for inhaled delivery. Finally, judging by the interest from numerous pharmaceutical companies, it appears the stage is set for tryptase inhibitors to make their mark as drugs of the future for allergic asthma and the results from clinical trials is awaited with eager anticipation.
...
PMID:Inhibitors of mast cell tryptase beta as therapeutics for the treatment of asthma and inflammatory disorders. 1560 28


1 2 3 Next >>

---