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:3.2.1.31 (beta-glucuronidase)
7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In dystrophic hamsters, increases in the levels of cathepsin B plus L and thiol proteinase inhibitor were marked in skeletal muscle, but only slight in heart muscle. The lysosomal hydrolases did not increase in parallel in dystrophic muscle: cathepsin B plus L and beta-glucuronidase increased, but cathepsin C and acid phosphatase did not. In immunohistochemical studies with antibodies against rat liver cathepsin B and thiol proteinase inhibitor, the proteinase and inhibitor were both stained in phagocytes, chiefly macrophages, but not in muscle cells, indicating that the increases in cathepsin B plus L and thiol proteinase inhibitor in dystrophic muscle are due to their presence in invading phagocytes. The levels of cathepsin B plus L, beta-glucuronidase and thiol proteinase inhibitor in isolated peritoneal macrophages were 50 to 180 times higher than those in skeletal muscle, but the levels of acid phosphatase and cathepsin C were only about 10 to 30 times those in skeletal muscle. Plots of the cathepsin B plus L activities versus the level of thiol proteinase inhibitor in homogenates of tissues of various animals showed an exponential rather than a linear relation between the two activities, suggesting that the syntheses of the proteinases are higher than that of the inhibitor in phagocytes invading dystrophic muscle.
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PMID:Increases in cathepsins B and L and thiol proteinase inhibitor in muscle of dystrophic hamsters. Their localization in invading phagocytes. 653 Apr

Three experiments were designed to study the lysosomal changes associated with the development and maintenance of the endurance training induced resistance against exercise injuries in mouse skeletal muscles. The activities of arylsulphatase, cathepsin C, cathepsin D, and beta-glucuronidase were assayed from the red part of mouse quadriceps femoris muscle 4 days after prolonged strenuous running of 4-9 h duration. Exercise injuries were characterized by necrotic fibers and focal inflammation. Strenuous running of untrained mice induced necrotic lesions and a 4-5 fold increase in the activities of lysosomal enzymes. This lysosomal response was considerably reduced already by daily training bouts on the 3 days preceding the strenuous exertion. Simultaneously exercise injuries were markedly reduced. Extending the endurance training program increased the running ability of mice and further reduced the necrotic lesions and lysosomal changes induced by the strenuous exercise. The detraining of 1 week after the termination of regular endurance training considerably increased the degree of exercise induced lysosomal response. The detraining of longer durations further increased the lysosomal response and no effect of prior endurance training existed after 1 month detraining. Our observations suggest that the severity of exercise injuries is related to the strength of the exercise stimulus and the level of preceding physical activity and can be characterized by the lysosomal changes.
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PMID:Lysosomal changes related to exercise injuries and training-induced protection in mouse skeletal muscle. 672 Mar 24

Male NMRI-mice, aged 3, 6, 9, and 12 months, were made to run for a period of 4 4 at a speed of 13.5 m/min on a motor-driven treadmill, 5 days after exertion, selected enzymatic estimates of acid and alkaline proteolytic as well as energy metabolic capacities were analyzed from the cardiac muscle and from the red and white parts of m. quadriceps femoris (MQF). The activities of alkaline and myofibrillar proteases increased most considerably in skeletal muscles with age. Cathepsin D and beta-glucuronidase activities were less affected in both muscles. Prolonged running increased the activities of cathepsin D, dipeptidyl aminopeptidase I and beta-glucuronidase in the white and, especially in the red part of MQF. This stimulation of acid hydrolytic capacity was more prominent at the ages of 3 and 6 months than in the older animals. The estimates of alkaline proteolytic or energy metabolic capacities were not affected by prolonged running. In cardiac muscle, no significant changes were recorded in acid hydrolytic or energy metabolic capacity. Histological observation showed no necrosis or other pathological phenomena in the proximal part of m. rectus femoris after excretion. We suggest that the increased acid proteolytic capacity is involved in subcellular regenerative processes of skeletal muscle fibres. The smaller lysosomal response of older mice may indicate a reduced potential capacity for cellular repair.
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PMID:Effects of age and prolonged running on proteolytic capacity in mouse cardiac and skeletal muscles. 702 79

1. Activities of dipeptidyl aminopeptidases (DAP), leucine arylamidase and beta-glucuronidase were assayed in red and white parts of mouse quandriceps femoris muscle 3 and 7 days after a single bout of prolonged running. 2. The activities of lysosomal acid hydrolases (DAP I, DAP II and beta-glucuronidase) were highly increased on the 3rd day after the exertion and then decreased by the 7th day. The response was more prominent in red than in white skeletal muscle. 3. The activities of two microsomal hydrolases, DAP IV and leucine arylamidase, increased much less than those of the lysosomal acid hydrolases. The highest activities were recorded on the 7th day after exertion. 4. The activity of DAP III, a cytoplasmic peptidase, was unaffected in red muscle but slightly increased in white muscle. 5. The protein content of red skeletal muscle, but not that of white muscle, decreased transiently after the running. 6. It seems that strenuous exercise selectively stimulates the lysosomal proteolytic system in skeletal muscle, while the others are less affected.
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PMID:Changes of dipeptidyl aminopeptidase activities in mouse skeletal muscle following prolonged running. 703 82

The content of 5 lysosomal hydrolases was examined in the rat liver and blood serum after compression of hind limb soft tissues in the presence of a long-term intake of excess doses of pyridoxine, riboflavin and glutamic acid. It was shown that the 14-day application of the drug complexes dramatically increased the overall content of cathepsin C, arylsulfatases A and B, beta-glucuronidase and p-acetyl-beta-D-galactosaminidase and reduced the overall content of cathepsin D in the rat liver. The non-sedimented content of the enzymes did not practically differ from the control magnitudes. In the blood serum, the content of cathepsin C and B1 approximated that seen in the control, while that of arylsulfatases A and B and p-acetyl-beta-D-galactosaminidase decreased, whereas the beta-glucuronidase content was 75% higher as compared to the basic characteristics. In the presence of administering the drug complexes, severe mechanical injury entailed the lowering of the content of the majority of rat liver lysosomal hydrolases. Besides, one could observe an essential fall of the non-sedimented content of cathepsin C and arylsulfatases A and B. The blood serum demonstrated an appreciable decrease in the content of cathepsins C and B1, p-acetyl-beta-D-galactosaminidase and arylsulfatases A and B. Thus, the fall of the non-sedimented content and diminished release of lysosomal hydrolases into the systemic circulation attest to the preservation of the structural and functional integrity of the liver cell lysosomal system during severe mechanical injury in the presence of combined excess intake of pyridoxine, riboflavin and glutamic acid.
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PMID:[Effect of pyridoxine, riboflavin and glutamic acid on lysosomal hydrolase activity in the liver and serum of rats during traumatic stress]. 715 Jul 36

To determine the effects of lipid accumulation on proteoglycan synthesis, we studied proteoglycan biosynthesis in rabbit aortic smooth muscle cells in culture. Cholesterol-enrichment was accomplished by incubating confluent smooth muscle cells with cationized low-density lipoprotein. Control and cholesterol-enriched cells were incubated with [35S]sulphate, [3H]glucosamine, or [3H]serine. Metabolically labelled proteoglycans in the cell layer and medium were quantified. During a 20 h incubation period, proteoglycan synthesis in cholesterol-enriched cells increased by 40-50% above that in control cells. A similar increase in precursor incorporation into proteoglycans was also noted following a short 15 min pulse. The cholesterol-enriched cells also showed a 45-50% increase over control rates in the intralysosomal accumulation of a large chondroitin sulphate proteoglycan and a small dermatan sulphate proteoglycan. The enhanced synthesis of proteoglycans in cholesterol-enriched cultures was inhibited by cycloheximide and actinomycin D, which are inhibitors of protein synthesis and transcription respectively. Proteoglycan turnover was investigated by pulse-chase analysis. Following a 2-h pulse, intracellular proteoglycans in cholesterol-enriched cells disappeared, having a half-life of 26.5 h compared with 2.8 h for those in the control cells. The amount of trypsin-releasable proteoglycan was significantly reduced in cholesterol-enriched cells. In addition, the degradation of proteoglycans was severely retarded in cholesterol-enriched cultures. The activities of three acid hydrolases, N-acetyl-beta-hexosaminidase, beta-glucuronidase and cathepsin C, were significantly reduced in cholesterol-enriched cells compared with activities in control cells. The results indicate that proteoglycan metabolism is altered in cholesterol-enriched smooth muscle cells.
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PMID:Enhanced synthesis and accumulation of proteoglycans in cholesterol-enriched arterial smooth muscle cells. 837 76

The distribution of the cation-independent mannose 6-phosphate and 78 kDa receptors was studied in postnuclear subcellular fractions from two rat liver cell lines. ELISA assays revealed that the mannose 6-phosphate receptor is enriched in the light buoyant Percoll fractions that contain Golgi structures and early endosomes. Most of the 78 kDa receptor is localized in a heavy fraction at the bottom of the Percoll gradient and smaller amounts in the endosomal fractions. The high-density compartment is denser than lysosomes, contains LAMP2 but not LIMPII or acid hydrolases, and is not disrupted with glycyl-l-phenylalanine 2-naphthylamide, a substrate for cathepsin C that selectively disrupts lysosomes. Immunofluorescence microscopy studies indicate no colocalization of the 78 kDa receptor with the mannose 6-phosphate receptor or LIMPII. Mannose 6-phosphate-independent endocytosed beta-glucuronidase was found in the lysosomal, the early and late endosomal fractions. These fractions were immunoadsorbed in columns containing antibodies against the 78 kDa receptor. Only the endocytosed beta-glucuronidase present in the early and late endosomal fractions is associated to immunoadsorbed vesicles. In these vesicles, LAMP2 was detected but no LIMPII or the mannose 6-phosphate receptor. Results obtained suggest that the 78 kDa receptor is found along the endocytic pathway, but in vesicles different from the cation-independent mannose 6-phosphate receptor.
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PMID:Cation-independent mannose 6-phosphate and 78 kDa receptors for lysosomal enzyme targeting are located in different cell compartments. 1608 51

Lysosomal changes of mouse skeletal muscle during the repair of exercise injuries were studied with biochemical, histochemical, and electron microscopic methods. Treadmill running for 4 hours and 9 hours increased the activities of cathepsin C and beta-glucuronidase, but not that of beta-glycerophosphatase in mouse quadriceps femoris muscle. The highest activities occurred 3 days after exertion and were higher after the longer duration of exertion. Similar changes that were highly correlated with the activities of lysosomal enzymes occurred in the activities of glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase and in the concentration of DNA. The activities of lysosomal enzymes correlated significantly with the severity of histopathologic injuries. Histochemical stainings of beta-N-acetylglucosaminidase and beta-glucuronidase showed a strong increase in the staining intensity 3 and 5 days after exertion, both in inflammatory phagocytes and in surviving muscle fibers in the injured area, and staining intensities increased in parallel with the severity of injuries. Electron microscopy showed an increased number of autophagic vacuoles, lysosome-like bodies, and Golgi complexes in the fibers adjacent to necrotic foci, coinciding with the highest histochemical staining pattern. Lysosomal changes in surviving muscle fibers in close proximity to injured muscle fibers could, by autophagic degradation, provide structural elements for the regeneration of injured muscle fibers.
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PMID:Lysosomal changes in mouse skeletal muscle during the repair of exercise injuries. 1675 92

A number of studies, mostly performed ex vivo, suggest that lysosomes are involved in apoptosis as a result of a release of their cathepsins into the cytosol. These enzymes could then contribute to the permeabilization of the outer mitochondrial membrane; they could also activate effector caspases. The present study aims at testing whether the membrane of liver lysosomes is disrupted during Fas-mediated cell death of hepatocytes in vivo, a process implicated in several liver pathologies. Apoptosis was induced by injecting mice with aFas (anti-Fas antibody). The state of lysosomes was assessed by determining the proportion of lysosomal enzymes (beta-galactosidase, beta-glucuronidase, cathepsin C and cathepsin B) present in homogenate supernatants, devoid of intact lysosomes, and by analysing the behaviour in differential and isopycnic centrifugation of beta-galactosidase. Apoptosis was monitored by measuring caspase 3 activity (DEVDase) and the release of sulfite cytochrome c reductase, an enzyme located in the mitochondrial intermembrane space. Results show that an injection of 10 microg of aFas causes a rapid and large increase in DEVDase activity and in unsedimentable sulfite cytochrome c reductase. This modifies neither the proportion of unsedimentable lysosomal enzyme in the homogenates nor the behaviour of lysosomes in centrifugation. Experiments performed with a lower dose of aFas (5 microg) indicate that unsedimentable lysosomal hydrolase activity increases in the homogenate after injection but with a marked delay with respect to the increase in DEVDase activity and in unsedimentable sulfite cytochrome c reductase. Comparative experiments ex vivo performed with Jurkat cells show an increase in unsedimentable lysosomal hydrolases, but much later than caspase 3 activation, and a release of dipeptidyl peptidase III and DEVDase into culture medium. It is proposed that the weakening of lysosomes observed after aFas treatment in vivo and ex vivo results from a necrotic process that takes place late after initiation of apoptosis.
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PMID:Lysosomes and Fas-mediated liver cell death. 1712 11


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