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:3.1.21.1 (DNase)
7,655 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have developed an enzymatic technique for isolating human intestinal mucosal lymphoid cells. This method was found to be superior to mechanical methods in regard to cell yield and survival. It is based on treating mucosa with serum-free solutions containing collagenase and deoxyribonuclease, followed by isolating the lymphoid cells through centrifugation steps involving fetal calf serum and ficoll-hypaque. Exposure of peripheral blood lymphocytes to the components of the enzymatic solution did not appreciably alter their uptake of tritiated thymidine in the presence or absence of mitogens. Application of the method to derive lymphoid cells from Crohn's disease, ulcerative colitis, and normal intestinal mucosa has shown that gut mucosal lymphocytes from inflammatory bowel disease (1) exceed the number of those from normal mucosa by a factor of 3 to 5; (2) show different degrees of tritiated thymidine uptake, spontaneously and in response to mitogens, depending upon the time they are harvested during the dissociation process; (3) are better stimulators than responders in the allogeneic mixed lymphocyte reaction; (4) generate suppressor cell activity comparable to that of peripheral blood lymphocytes; (5) cannot, in contrast to peripheral blood lymphocytes, generate antibody-dependent cell mediated cytotoxicity; and (6) produce an average of 5 times more IgM than equal numbers of peripheral blood lymphocytes.
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PMID:Gut mucosal lymphocytes in inflammatory bowel disease: isolation and preliminary functional characterization. 15 97

Lymphocytes infiltrating synovial membranes were characterized in eight patients with proliferative rheumatoid synovitis. Surface immunoglobulins were studied with use of immunofluorescence, and the C3 receptor was detected by adherence of red cells coated with antibody and complement - both are B-cell markers. Spontaneous rosette formation with sheep erythrocytes was used as a T-cell marker. To obtain viable lymphocytes in suspension, the villous synovium of five of these patients was digested with collagenase and deoxyribonuclease. Populations enriched in lymphocytes could be obtained by velocity sedimentation. Whereas only 9 to 35 per cent of lymphocytes bore surface immunoglobulins, the majority (70 to 85 per cent) formed sheep-erythrocyte rosettes. Cells bearing the C3 receptor constituted a distinct minority of synovial lymphocytes in frozen-tissue sections, and were found in follicle-like accumulations. These data indicate that the predominant infiltrating lymphocyte in proliferative rheumatoid synovitis is a T cell.
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PMID:Predominantly T-cell infiltrate in rheumatoid synovial membranes. 16 88

The ascites form of a chemically induced guinea pig hepatoma, line-10, was resistant to killing in vitro by xenogeneic antibody and guinea pig complement. Pretreatment of line-10 cells with certain proteolytic enzymes rendered tham susceptible to the killing action of antibody and guinea pig complement. The effects of enzyme pretreatment were dependent on enzyme concentration, temperature, and could be blocked by addition of competitive or non-competitive inhibitors. The effect of the enzyme treatment could reversed by incubating the treated cells at 37 degrees C (but not at 0 degrees C), in the absence of the enzyme. Effective enzymes included ficin, bromelain, pronase, elastase, papain, trypsin, collagenase, lipases type I and type VI, and the neuraminidase preparation isolated from Clostridium perfringens. The activity of the lipase preparations and the neuraminidase preparation isolated from Clostridium perfringens appeared to be caused by proteolytic enzyme contamination. Enzyme preparations that proved ineffecitve in rendering the line-10 cells sensitive to killing by antibody and guinea pig complement included DNase, RNase, beta-glucuronidase type 6A or type B10, hyaluronidase type V or type VI, and pectinesterase.
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PMID:Lysis of tumor cells by antibody and complement. VI. Enhanced killing of enzyme-pretreated tumor cells. 17 70

To evaluate extracellular hydrolytic enzymes in an in vivo system, plastic chambers were glued over rabbit dermal BCG lesions in various stages of development, after the central epithelium was removed with a scalpel. They were filled with tissue culture medium and left in place 2 days. The following enzymes in the fluid were assayed: collagenase (an enzyme secreted but not stored in macrophages); lysozyme (both secreted and stored); DNase and RNase (released on cell death and possibly regurgitated but not secreted); and, as a control, lactic dehydrogenase (released only on cell death). Tissue sections were prepared and studied histologically for the type of cell infiltrate, for beta-galactosidase (our marker enzyme for macrophage activation), and for necrosis. At 11 and 18 days of age the BCG lesions were largest and the number of activated macrophages in the chamber beds was highest. At this time the levels of the five enzymes assayed in the chamber fluids reached their peaks, tuberculin hypersensitivity was well developed, and the bacilli components would still be plentiful. In general, the chamber fluids from 11- and 18-day BCG lesions contained higher enzyme levels than chamber fluids from tuberculin reactions. Active collagenase was only detected in fluids from such BCG lesions. Evidently, the serum in the chamber fluids was sufficient to inhibit the lower amounts of collagenase probably released from smaller BCG lesions and tuberculin reactions (and from the 2-week polystyrene lesions that were also evaluated). These studies demonstrate that in chronic inflammatory reactions, both acid-acting and neutral-acting hydrolytic enzymes are released extracellularly. Tissue components would be hydrolyzed locally wherever the acid-acting hydrolytic enzymes encounter a drop in pH and wherever the concentration of neutral-acting hydrolytic enzymes exceeds the concentration of their inhibitors.
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PMID:Extracellular hydrolytic enzymes of rabbit dermal tuberculous lesions and tuberculin reactions collected in skin chambers. 20 93

Isolation of blood and intracellular forms of Trypanosoma cruzi was made mainly from rats (90-110 g) which had received 580 rad of whole-body gamma-irradiation not more than 24 h before subcutaneous inoculation with 10(7) trypomastigotes of the Sonya strain of T. cruzi. Unirradiated chinchillas (250-350 g) were, however, used for some experiments. Blood forms were isolated using a technique involving differential centrifugation to remove most of the erythrocytes and DEAE-cellulose chromatography to remove the remaining blood cells. Overall recoveries were usually in the range 30-70%. Parasites were mainly (approximately 98%) broad forms and were motile, metabolically active (as judged by respiratory and radio-tracer incorporation studies) and had lost none of their infectivity for mice. Intracellular forms were isolated from hind-limb muscle tissue. This was disrupted in an MSE tissue homogenizer and the homogenate incubated with DNase, collagenase and trypsin. Parasites, contaminated only by a few blood cells, were then obtained by differential centrifugation. For purer preparations, a terminal sucrose gradient step was used. Recoveries ranged between 40 and 70%. About 1-3% of the parasites isolated were epimastigotes and trypomastigotes; the remainder are probably best collectively termed 'amastigotes', though they were pointed and most had a short, free flagellum. They were undamaged as judged by light and electron microscopy and metabolically active as judged by respiratory and radio-tracer incorporation studies. However, the infectivity for mice of both these purified preparations and the initial cell homogenates could be accounted for by the epimastigotes and trypomastigotes present in them. Preliminary biochemical studies with isolated parasites have shown that blood, intracellular and culture forms of T. cruzi have a respiratory system which is in part sensitive to CN- and that all forms synthesize nucleic acids and proteins when incubated in vitro. There appears, however, to be a lack of DNA synthesis in blood stages, and thus it is not surprising that these forms do not divide.
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PMID:Isolation of blood and intracellular forms of Trypansoma cruzi from rats and other rodents and preliminary studies of their metabolism. 20 67

Properties of prolactin receptors were measured by monitoring [125I]prolactin binding to specific receptor sites on collagenase-dissociated mammary epithelial cells of virgin, pregnant and lactating mice. On a Scatchard plot the data generated a straight line and the estimated dissociation constant (Kd) and number of receptor sites on lactating cells were 0.9 x 10(-9) and 1540 per cell. The [125I]prolactin binding was inhibited in presence of unlabeled prolactin and other lactogenic polypeptide hormones, but not by nonlactogenic polypeptide hormones. The [125I]prolactin binding was sensitive to pronase and trypsin but not to DNAase, RNAase and hyaluronidase. Scatchard plot analysis further showed that while the number of receptors on mammary cells was variable at different stages of endocrine regulated developmental changes of the gland, Kd of the hormone--receptor complex generally remained similar. The high level of prolactin receptors on mammary cells of virgins was reduced during pregnancy and the lactating mammary cells showed a highly elevated level of prolactin receptors. The results demonstrate that specific prolactin receptors can be measured on collagenase dissociated mammary epithelial cells and this method permits a direct assessment of the number of receptors on a per cell basis rather than indirect estimates, based on average DNA or protein content of the tissue, composed of heterogeneous cell types.
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PMID:Prolactin receptor on dissociated mammary epithelial cells at different stages of development. 21 95

Heart-cell conditioned medium (HCM) induces rapid neurite outgrowth from isolated neurons in culture. The following evidence indicates that this action of HCM is due to a trypsin-sensitive factor which attaches to the polyornithinecoated culture substratum: (i) Pretreatment of the culture substratum with HCM allows rapid neurite outgrowth to occur even in unconditioned media. The active factor remains bound to the substratum during the period of neurite outgrowth. (ii) The substratum-bound activity is destroyed by trypsin treatment, but is insensitive to collagenase, RNase, and DNase. (iii) The factor that binds to the substratum is essential for neurite outgrowth, because HCM is no longer active when the material that binds to the polyornithine substratum has been removed by passage of the HCM over a series of culture dishes. However, this "depleted" HCM is still able to support the growth of nonneuronal cells. (iv) Most significantly, when neurons are cultured in whole HCM, the extent of neurite outgrowth is proportional to the amount of substratum-bound activity and not to the amount in solution, indicating that the substratum-bound form of the factor is more active. Previous observations [Collins, F. (1978) Dev. Biol. 65, 50-57] suggest that HCM promotes neurite outgrowth by increasing the adhesion between nerve cell surface extensions and the polyornithine-coated culture substratum. It is possible, therefore, that the factor in HCM that binds to the substratum possesses sites to which nerve cell surface components adhere.
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PMID:Induction of neurite outgrowth by a conditioned-medium factor bound to the culture substratum. 21 18

A simple two-step procedure was developed for isolation of lymphocytes from chronically inflamed human synovial membranes. In the first step minced inflamed synovial tissues are disrupted enzymatically by deoxyribonuclease and collagenase. The second step consists of nylon-wool column filtration of the isolated cells. 7 min of preincubation of up to 37.4 X 10(6) cells in a column packed with 600 mg nylon-wool in 6 ml prior to filtration did not result in significant selective losses of either T or B cells, whereas 45 min of preincubation did. Recovery of lymphocytes after nylon-wool column filtration ranged from 68 to 95% (mean 80%) and viability was always higher than 90%. Nylon-wool column filtration increased the proportion of lymphocytes by a mean 73%. The method allows rapid identification of synovial tissue lymphocyte subpopulations as well as characterization of their function.
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PMID:Lymphocyte isolation from chronically inflamed synovial membranes. 30 51

During the first 10 days after peripheral deafferentation of the mouse olfactory bulb stereoselective binding of L-[3H]carnosine declines markedly. The initial phase of this decline is due to a decrease in binding site stereoselectivity, which is then followed by a loss of assayable binding sites. The specificity of inhibition of L-[3H]carnosine binding by various peptides is also altered after denervation. Competitive inhibitors of carnosine binding become less potent after denervation, while analogues which are not competitive inhibitors remain equipotent before and after denervation. Several carnosine analogues that are normally poor inhibitors become more potent after denervation. Treatment of bulb membranes with trypsin, RNase and hyaluronidase, but not DNase or collagenase, resulted in significant alterations in carnosine binding. L-, but not D-carnosine, protected the binding site from trypsin digestion, and induced additional binding in bulb membranes in a dose-and temperature-dependent fashion. Preincubation of membranes with L-carnosine also led to the induction of additional carnosine binding in membranes from cerebral cortex, cerebellum and deafferentated bulbs but not from muscle. Bulbs from newborn mice contain about one-half of the adult levels of binding and no significant sex differences in carnosine binding were detected in bulbs from adult rats. L-[3H]carnosine binding was two-fold higher in the anterior compared to the posterior portion of the bulb, but there were no significant differences in binding of opiate, GABA, alpha-adrenergic, muscarinic cholinergic, benzodiazepine of glutamic acid receptor ligands.
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PMID:L-[3H]Carnosine binding in the olfactory bulb. II. Biochemical and biological studies. 48 25

The intraperitoneal administration of [3H]thymidine to adult rats resulted in the rapid appearance of label in the adipocyte fraction of collagenase digests of adipose tissue. Low-speed centrifugation followed by freezing and slicing showed the label to be uniformly distributed in the adipocyte fraction. The presence of label in DNA was confirmed by hydrolysis with deoxyribonuclease and by inhibition of incorporation with hydroxyurea. Organelle fractionation revealed that the label was predominantly in nuclei, and radioautography showed that only a few adipocyte nuclei were labeled. The label in the adipocyte fraction could not be reduced by increased collagenase digestion or by trypsin treatment. Mixing of labeled adipocytes with unlabeled stroma did not result in decrease of label and addition of labeled stroma to unlabeled adipocytes did not cause significant transfer of radioactivity. Addition of [3H]thymidine to the collagenase digestion medium of unlabeled adipose tissue resulted in more incorporation by adipocytes than by stroma, suggesting the presence of a very rapidly proliferating cell type associated more with adipocytes than with stroma. In vivo turnover studies of labeled DNA indicated that there are two components in both adipocytes and stroma, a rapidly labeled component with a half-life of only several days and another with a half-life of several months. These experiments suggest that there is a rapidly proliferating cell type in adipose tissue, closely associated with mature adipocytes, that may be an adipocyte progenitor or may have some other unknown function.
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PMID:Isotopic labeling of DNA in rat adipose tissue: evidence for proliferating cells associated with mature adipocytes. 49 48


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