Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.31 (beta-glucuronidase)
 7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Leupeptin is an established, reversible inhibitor of cathepsin B, a lysosomal cysteine proteinase. Yet, in rat fibroblasts as well as in foetal mouse calvaria, we observed an increase of the activity of cathepsin B in homogenates of cells and tissue harvested after culture in the presence of leupeptin. This effect was also seen for other lysosomal hydrolases, namely sphingomyelinase, N-acetyl-beta-glucosaminidase, arylsulphatase A and phospholipase A1 in fibroblasts, and beta-glucuronidase in mouse calvaria. In calvaria, antipain, another reversible cysteine proteinase inhibitor, caused a similar effect, whereas E-64, an irreversible inhibitor, was consistently inhibitory of the cathepsin B activity; yet it also caused an increase of beta-glucuronidase activity. The effect of leupeptin in fibroblasts was dose and time-dependent, required the continuous presence of the inhibitor, and was not dependent from protein synthesis. Actually, addition of cycloheximide caused a severe loss of activity of cathepsin B and of sphingomyelinase. In the presence of both cycloheximide and leupeptin, however, these two activities were retained to a value corresponding to that found in excess in cells cultivated with leupeptin alone. The data therefore suggests that leupeptin exerts the effects described in this paper by preventing the degradation of cathepsin B, sphingomyelinase and probably several other lysosomal hydrolases by cysteine proteinases. We therefore propose that cysteine proteinases play a key role in the control of the steady-state levels of these enzymes in normal conditions.
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PMID:Increased activities of cathepsin B and other lysosomal hydrolases in fibroblasts and bone tissue cultured in the presence of cysteine proteinases inhibitors. 793 17

The effect of curcumin on lysosomal hydrolases in serum and heart was studied by determining the activities of beta-glucuronidase, beta-N-acetylglucosaminidase, cathepsin B, cathepsin D, and acid phosphatase. Rats treated with isoproterenol (30 mg/100 g body weight) showed a significant increase in serum lysosomal hydrolase activities, which were found to decrease after curcumin treatment. Isoproterenol administration to rats resulted in decreased stability of the membranes, which was reflected by the lowered activity of cathepsin D in mitochondrial, lysosomal, and microsomal fractions. Curcumin treatment returned the activity levels almost to normal, showing that curcumin restored the normal function of the membrane. Histopathological studies of the infarcted rat heart also showed a decreased degree of necrosis after curcumin treatment.
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PMID:Effect of curcumin on certain lysosomal hydrolases in isoproterenol-induced myocardial infarction in rats. 853 67

Glucocorticoids have been used in the treatment of a number of diseases where immunological intolerance plays a predominant role. Since immunological intolerance points to the involvement of lysosomal enzymes and glucocorticoids are known to affect their activities, we have attempted to study the effect of these steroids on cardiac and renal enzymes. Dexamethasone, a glucocorticoid, is administered subcutaneously to male Wistar rats at a dosage of 2.5 mg/kg/week on alternate days for two weeks. After withdrawing the steroid, the animals are monitored for one week to oversee the recovery process. Total and free activities of glycohydrolases and cathepsins in serum, heart and kidney are assayed on the days 4, 8, 12, 16 of dexamethasone administration and also on days 4 and 8 following discontinuation of the steroid. During dexamethasone administration, a significant decrease in both the free and total activities of beta-glucuronidase, beta-N-acetyl glucosaminidase, beta-galactosidase, alpha-galactosidase, alpha-mannosidase, cathepsin B and cathepsin D are observed in heart and kidney, but the enzyme levels are shown to increase in serum. On withdrawal of the steroid, the activities of beta-glucuronidase, beta-N-acetyl glucosaminidase, beta-galactosidase are found to be increased in heart and kidney, whereas, the activity of alpha-mannosidase remains within normal values. Thus, it could be seen that dexamethasone alters the pattern of glycohydrolases and cathepsins, which are involved in protein degradation.
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PMID:Alterations in certain lysosomal glycohydrolases and cathepsins in rats on dexamethasone administration. 871 30

Activity of beta-glucuronidase (GL), placentar izoenzyme of alkaline phosphatase (PLAP), cathepsin B (CB) and concentrations of carcinoembryonic antigen (CEA) were determined in serums and bile of pigs with experimental cholangiocarcinoma and in control animals. No differences in serum GL, PLAP, CB activities or CEA were observed. The same was found in bile for GL, PLAP and CEA. However, in bile the situation was different for CB. In all the tumour bearing animals we were able to demonstrate in the course of tumour development a stricking progression in CB activity. Very impressive was namely an elevation of CB alkaline-stable form, generated (according also to the chromatographic studies of the bile) from primary cholangiocarcinoma tissue.
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PMID:[Cathepsin B-like substance in the monitoring of chemically induced primary cholangiocarcinoma in swine]. 896 25

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

The pathogenesis of periodontitis involves anaerobic oral bacteria as well as the host response to infection and several drugs have been developed which can curtail these deleterious effects. Proanthocyanidin, a novel flavanoid extracted from grape seeds, has been shown to provide a significant therapeutic effect on endotoxin (Escherichia coli) induced experimental periodontitis in rats. In this study, protective action of different doses of proanthocyanidins was investigated in blood by assaying the reactive oxygen species such as hydrogen peroxide, superoxide anion, myeloperoxidase and lipid peroxides, lysosomal enzyme activities such as cathepsin B, cathepsin D, beta-glucuronidase and acid phosphatase, nonenzymatic antioxidants such as ascorbic acid, alpha-tocopherol, ceruloplasmin, reduced glutathione and antioxidant enzymes such as catalase, superoxide dismutase, glutathione peroxidase and glutathione-s-transferase. Experimental periodontitis rats showed a reduction in body weight and body weight gain could be noticed when they were administered proanthocyanidins. The levels of reactive oxygen species and lysosomal enzymes were found to increase whereas antioxidant levels were decreased significantly in experimental periodontitis. Proanthocyanidins at an effective dose of 30 mg/kg body weight, sc, for 30 days effected a decrease in serum reactive oxygen species, lipid peroxides, lysosomal enzymes, acute phase proteins and an increase in antioxidant levels. Histopathological evidence of experimental periodontitis showed cellular infiltration of inflammatory cells while proanthocyanidin treated groups demonstrated only scattered inflammatory cells and blood vessels. Thus, the results showed that dietary supplementation of proanthocyanidin enhanced the host resistance as well as the inhibition of the biological and mechanical irritants involved in the onset of gingivitis and the progression of periodontal disease.
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PMID:Protective effect of proanthocyanidins on endotoxin induced experimental periodontitis in rats. 2045 22


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