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

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Query: EC:3.4.23.5 (cathepsin D)
4,130 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The levels of six lysosomal enzymes (acid phosphatase, beta-acetylglucosaminidase, cathepsin D, beta-galactosidase, arylsulfatase A, and beta-glucuronidase) and four neutral and alkaline hydrolases (esterase, inorganic phyrophosphatase, alkaline phosphatase, and 5'-nucleotidase) were measured in osteoarthritic, rheumatoid and control synovia. All enzyme levels in diseased synovium except esterase values in osteoarthritis were significantly elevated compared with controls. The mean values of the group of acid hydrolases and the group of neutral and alkaline hydrolases in osteoarthritic synovia were 1.9- and 2.0-fold greater than those of control specimens. In rheumatoid synovia, the values were 4.2- and 4.5 fold greater than control for the same enzymes. Levels in rheumatoid synovia were significantly higher than those in osteoarthritic synovia with the exception of 5'-nucleotidase. Only a limited correlation between the extents of inflammation present in the synovia and the levels of a lysosomal marker enzyme (cathepsin D) was observed. These results demonstrate that whatever the mechanism, increased levels of acid hydrolases as well as certain neutral and alkaline hydrolases are present in osteoarthritic and rheumatoid synovia, and these enzymes are probably contained in the synovial lining cells.
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PMID:Acid, neutral, and alkaline hydrolases in arthritic synovium. 0 9

It is evident that human articular cartilage possesses, in addition to multiple forms of cathepsin D, multiple forms of other acid cathepsins, and, most important, a family of at least four closely related neutral protease enzyme forms, all of which degrade proteoglycan. In addition, caseinase and histonase activities are present. The search for these enzymes in human cartilage ahs been presented in some detail in order to give an idea of some of the problems faced in such research, as well as the hypotheses and hopes that flow from it and prepare the ground for further research. The actual role of proteolytic enzymes in the physiologic and pathologic condition of cartilage remains to be determined. It is hoped that these enzymes, especially the neutral protease forms, will be sufficiently purified to enable preparation of antibodies to them. This will help to clarify what controls their release from the chondrocytes and where they function in the cartilage. Meanwhile, it seems appropriate to study the neutral protease forms and their role in initiating the degradation of proteoglycan in the early stages of osteoarthritis. The chief role of cathepsin D and the new acid cathepsins is most likely in intracellular digestion. One may hypothesize a three-step sequence of the degradation of the matrix proteoglycan: (1) initial extracellular attack by the neutral matrix, (2) endocytosis of the fragments by the cells, and (3) completion of their degradation within the lysosomal digestive system of the cell. The initial degradation of the matrix proteoglycan would facilitate the entrance of other degrading enzymes from the synovium to aid in total destruction of the cartilage. While awaiting knowledge of the primary events that trigger the development of osteoarthritis, enzymatic research offers the real hope of finding a way to control the enzymatic degradation of proteoglycan occurring in the early stages of the disease. Research into the nature of these degrading enzymes will lead to the development of therapeutically suitable inhibitors.
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PMID:Proteolytic enzymes in human cartilage: the pathogenesis of osteoarthritis. 97 57

Fragments of bovine plasma fibronectin produced by cathepsin D digestion are reportedly mitogenic for hamster fibroblasts. Rheumatoid arthritis synovial fluid contains many fibronectin fragments, which may contribute to the proliferation of synovial cells. We have therefore investigated the potential of fibronectin fragments to stimulate proliferation of synovial fibroblast-like cells using human material. Affinity-purified human plasma and synovial fluid fibronectin was digested with cathepsin D at pH 3.5 for 0-18 h and proteolysis stopped with pepstatin. A variety of fragments were produced ranging from 50 to 200 kDa when analysed by SDS-PAGE. The proliferative activity of various test preparations was studied using quiescent human skin and synovial fibroblasts. Tests were applied for 24 h to 10(4) cells and DNA synthesis measured by tritiated thymidine incorporation. Both undigested and peptides of fibronectin consistently failed to stimulate DNA synthesis in fibroblasts at all concentrations tested, compared with a phosphate-buffered saline control. This was in marked contrast to human synovial fluid from either rheumatoid arthritis or osteoarthritis patients, which stimulated DNA synthesis in the same system (P less than 0.01). Therefore, our data do not confirm the findings of previous studies in which animal materials were used. We can find no evidence that fibronectin fragments play a role in stimulating synovial proliferation in inflammatory arthritis.
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PMID:Synovial fluid fibronectin fragments: no evidence for a mitogenic effect on fibroblasts. 207 72

In order to investigate the relationship between the synovial inflammatory response and lysosomal enzyme activity in osteoarthritis, synovial specimens obtained from 19 osteoarthritic patients and control specimens from 10 normal joints were analysed for cathepsin D and acid phosphatase enzyme levels. In estimating enzyme activities methods previously developed for quantitative enzyme determination in cartilage were modified and applied to synovial tissues for the first time. In addition, samples of osteoarthritic synovium were histologically graded according to their degree of inflammation. It was found that in osteoarthritic synovium cathepsin D and acid phosphatase, which is a general marker for lysosomal enzyme activity, were significantly increased compared with normal control synovium. No significant relationship was found between the degree of synovial tissue inflammation and lysosomal enzyme activity.
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PMID:Biochemical and histological changes in osteoarthritic synovial membrane. 370 18

The lysosomal endopeptidase cathepsin D is the most abundant proteinase in chondrocytes. Its significance in the pathogenesis of cartilage matrix proteoglycan (PG) degradation in osteoarthritis (OA) is unclear. The extracellular localization of cathepsin D and its potential spatial relationship to areas of PG depletion has been studied in human femoral head OA cartilage. Enzyme was identified by indirect immunofluorescence using rabbit antisera developed against a highly purified cathepsin D preparation. PG distribution was assessed in parallel sections by safranin O staining. Specimens were selected to include regions of cartilage having minimal structural and cellular alterations, severe reduction in thickness, hypocellularity, multicellular chondrocyte clusters and varying degrees of PG loss. Cathepsin D was identified in chondrocytes. When overlying fibrous connective tissue pannus was present, extracellular enzyme was predominantly localized to the cartilage-pannus interface. Cathepsin D could not be demonstrated extracellularly in areas of cartilage that were partially or totally devoid of PG. Chondrocytes in damaged regions, particularly in the superficial and upper transitional zones showing diffuse hypercellularity and/or "brood" clusters, contained increased enzyme staining. Results fail to support a role for cathepsin D in extracellular matrix PG degradation. The potential significance of this enzyme in the pathogenesis of OA would appear relegated to intracellular catabolism. Its intracellular increase at pathologic sites is consistent with enhanced catabolic activity in such regions.
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PMID:Histologic assessment of cathepsin D in osteoarthritic cartilage. 376 40

In recent years the lysosomal cathepsins have been implicated as important agents in the physiological degradation of various cartilages. In the present study, the nature of cathepsin present in human articular cartilage was investigated by microtechniques and a possible role for cathepsins in the cartilage degradation observed in osteoarthritis was sought. The results of this study indicated that the hemoglobin and proteoglycan-digesting activity in the human cartilage observed is predominantly that of a cathepsin D-type enzyme. This cathepsin D-type enzyme activity was present in two to three times greater amounts in yellowish or ulcerated articular cartilage from patients with primary osteoarthritis than in control "normal" human cartilages. The human cathepsin D-type enzyme, as well as a highly purified cathepsin D from bovine uterus degraded proteoglycan subunit (PGS) maximally at pH 5. Both enzyme preparations were inactive on hemoglobin at pH 6-8, but degraded PGS considerably at neutral pH. The activity of the human cathepsin extract was not affected by reagents which inhibit or activate cathepsins A and B. Neutral proteases which are active on hemoglobin or are inhibited by diisopropylfluorophosphate (DFP) were not detected in these preparations, but contamination by another type of neutral protease cannot be excluded. Chloroquine inhibited the degradation of PGS at neutral pH by the human cartilage enzyme extract.
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PMID:The action of cathepsin D in human articular cartilage on proteoglycans. 426 83

Fibroblastoid synovial lining cells isolated from rheumatoid and other chronic inflammatory synovial tissue exhibit distinctive and sustained alterations in serial culture not commonly found in similarly cultured cells from osteoarthritic synovium. These are demonstrable using a multi-gene dot blot assay by labelling reverse transcribed fibroblast cDNA which is hybridized to plasmids containing relevant target gene inserts. Cultured synovial fibroblastoid cells from patients with chronic inflammatory synovitis expressed significantly higher levels of stromelysin, vimentin and TIMP-1 mRNA and lower levels of c-myc compared to cells isolated from osteoarthritis synovium although with considerable variation. Early fetal synovial lining cells were similar to cells from osteoarthritis synovium but vimentin expression was higher. Marked differences in patterns of gene expression between cell lines persisted through 10 serial passages over 6-8 months. In whole synovia, the average level of mRNA for stromelysin, vimentin, IL-4, IL-6, TIMP-1, cathepsin D, gelatinase, TGF alpha, c-fms and DR beta were preferentially expressed in inflammatory tissue while c-myc expression was higher in osteoarthritis synovium. Inflammatory synovium also expressed TNF alpha, IL-1 alpha, IL-1 beta, IL-2, c-sis, tissue plasminogen activator, CSF-1, and GM-CSF. This pattern resembles, in part, that found in cultured inflammatory fibroblasts but, in addition, gene products apparently reflecting the presence of activated monocytes and lymphocytes were detected. These results provide evidence that profiles of certain gene activation in cells from patients with inflammatory synovitis differ from those with non-inflammatory disease and suggest that the fibroblastoid cells are responsible for a considerable proportion of the altered phenotypic expression pattern in whole tissue. Furthermore, this modulated pattern of gene activation appears to be an intrinsic pro-inflammatory characteristic of the fibroblastoid cells initiated in response to chronic inflammation and persists for a prolonged period in the absence of other inflammatory cells.
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PMID:Sustained and distinctive patterns of gene activation in synovial fibroblasts and whole synovial tissue obtained from inflammatory synovitis. 809 Nov 28

Six men who had undergone hip replacements for degenerative joint disease or trauma subsequently had radical prostatectomies or cystoprostatectomies with bilateral pelvic lymph node dissections for adenocarcinoma of the prostate or transitional cell carcinoma of the urinary bladder. The hip prostheses implanted in three patients were known to contain cobalt-chromium alloy and titanium. The pelvic lymph nodes ipsilateral to the hip prosthesis in five patients and the bilateral pelvic nodes in the only patient with bilateral hip prosthesis had dark brown or black cut surfaces. These lymph nodes did not contain carcinoma but showed florid sinus histiocytosis characterized by large polygonal histiocytes filling and expanding sinuses and interfollicular regions. The foamy histiocytes contained cobalt-chromium and titanium microparticles by light microscopy, ultrastructure, and energy-dispersive x-ray microanalysis. The lymph nodes uninvolved by the histiocytic reaction lacked the heavy metal microparticles. Four cases were found to have a small number of polyethylene particles, which might have contributed to the histiocytic response. By immunohistochemistry, the foamy cells displayed immunoreactivity for lysozyme, alpha-1-antitrypsin, alpha-1-antichymotrypsin, and cathepsin D, providing additional support for their histiocytic derivation. To our knowledge, this is the first time that microparticles of cobalt-chromium and titanium that migrate from hip prostheses to pelvic lymph nodes have been shown to elicit a distinctive type of florid sinus histiocytosis. Pathologists should be aware of this characteristic foreign-body tissue response to avoid confusion with other types of sinus histiocytosis or with metastatic carcinoma.
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PMID:Sinus histiocytosis of pelvic lymph nodes after hip replacement. A histiocytic proliferation induced by cobalt-chromium and titanium. 827 30

Global scale molecular profiling of diseased tissues is an important first step to unravel candidate target molecules that are involved in the pathogenesis of a disease. We have performed a comparative molecular characterization at the transcriptome (microarray with 12 526 gene specificities) and proteome level (multi-Western blot PowerBlot with 791 antibodies) of synovial tissue from rheumatoid arthritis (RA) compared to osteoarthritis (OA) patients. From the panel of 791 antibodies, 260 (33%) detected their corresponding protein. Out of 58 unambiguous changes at the protein level only 16 coincided at the transcript level (28%). Stat1, p47phox and manganese superoxide dismutase were shown to be reproducibly overexpressed in RA versus OA synovial tissue by Western blots with a panel of 8 RA versus 8 OA samples. Cathepsin D was among the most prominent proteins scored to be underexpressed in RA by the PowerBlot whereas no differences of the respective transcript were observed. The lower abundance of cathepsin D protein in RA compared to OA tissue was also reproduced in other patient samples. Immunohistochemistry assigned the Stat1 protein in RA synovial tissue mainly to macrophages and T lymphocytes and the p47phox protein in particular to macrophages. In conclusion, our approach provided us with new candidate molecules for further analysis of rheumatic diseases and stressed the importance of studies at the protein level.
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PMID:From transcriptome to proteome: differentially expressed proteins identified in synovial tissue of patients suffering from rheumatoid arthritis and osteoarthritis by an initial screen with a panel of 791 antibodies. 1283 24

Articular cartilage is composed of cells and an extracellular matrix. The chondrocyte is the only cell type present in mature cartilage, and it is important in the control of cartilage integrity. There is currently a great lack of knowledge about the chondrocyte proteome. To solve this deficiency, we have obtained the first reference map of the human normal articular chondrocyte. Cells were isolated from cartilages obtained from autopsies without history of joint disease. Cultured cells were used to obtain protein extracts which were resolved by 2-DE and visualized by silver nitrate or CBB staining. Almost 200 spots were excised from the gels and analyzed using MALDI-TOF or MALDI-TOF/TOF MS. The analysis leads to the identification of 136 spots that represent 93 different proteins. A significant proportion of proteins are involved in cell organization (26%), energy (16%), protein fate (14%), metabolism (12%), and cell stress (12%). From all the identified proteins, annexins, vimentin, transgelin, destrin, cathepsin D, heat shock protein 47, and mitochondrial superoxide dismutase were more abundant in chondrocytes than in other types of mesenchymal cells such as Jurkat-T cells. As metabolic program of chondrocytes is altered in osteoarthritis and other rheumatic diseases, this proteomic map is an important tool for future studies on these pathologies.
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PMID:Proteomic characterization of human normal articular chondrocytes: a novel tool for the study of osteoarthritis and other rheumatic diseases. 1603 16


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