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:3.2.1.17 (lysozyme)
21,489 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Polar solvents induce terminal differentiation in the human promyelocytic leukemia cell line HL-60. The present studies describe the functional changes that accompany the morphologic progression from promyelocytes to bands and poly-morphonuclear leukocytes (PMN) over 9 d of culture in 1.3 percent dimethylsulfoxide (DMSO). As the HL-60 cells mature, the rate of O(2-) production increase 18-fold, with a progressive shortening of the lag time required for activation. Hexosemonophosphate shunt activity rises concomitantly. Ingestin of paraffin oil droplets opsonized with complement or Ig increases 10-fold over 9 d in DMSO. Latex ingestion per cell by each morphologic type does not change significantly, but total latex ingestion by groups of cells increases with the rise in the proportion of mature cells with greater ingestion capacities. Degranulation, as measured by release of beta-glucuronidase, lysozyme, and peroxidase, reaches maximum after 3-6 d in DMSO, then declines. HL-60 cells contain no detectable lactoferrin, suggesting that their secondary granules are absent or defective. However, they kill staphylococci by day 6 in DMSO. Morphologically immature cells (days 1-3 in DMSO) are capable of O(2-) generation, hexosemonophosphate shunt activity, ingestion, degranulation, and bacterial killing. Maximal performance of each function by cells incubated in DMSO for longer periods of time is 50-100 percent that of normal PMN. DMSO- induced differentiation of HL-60 cells is a promising model for myeloid development.
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PMID:Functional changes in human leukemic cell line HL-60. A model for myeloid differentiation. 22 36

Cyclosporin (Cs)A but not CsH inhibits activation of human lymphocytes. We studied the effects of CsA, CsD, and CsH on human neutrophil activation induced by chemoattractants and by various substances that circumvent receptor stimulation. CsH inhibited superoxide (O2-) formation induced by the chemotactic peptide, FMLP (30 nM), with a half-maximal effect at 40 nM. O2- formation was abolished by CsH at 1 microM. CsH increased the concentration of FMLP causing half-maximal activation of O2- formation from 30 nM to 0.8 microM and substantially reduced the stimulatory effect of FMLP at supra-maximally effective concentrations. The inhibitory effect of CsH on O2- formation was evident immediately after addition to neutrophils. CsH also markedly inhibited the increase in cytosolic Ca2+ ([Ca2+]i), beta-glucuronidase, and lysozyme release and aggregation stimulated by FMLP. CsA and CsD were considerably less effective than CsH to inhibit FMLP-induced O2- formation. CsA and CsD were without effect on exocytosis, rises in [Ca2+]i, and aggregation induced by the chemotactic peptide. Cyclosporines inhibited FMLP-induced O2- formation in an additive manner, indicating that they acted through a mechanism they had in common. Cyclosporines only slightly inhibited O2- formation and lysozyme release induced by C5a. Aggregation and rises in [Ca2+]i stimulated by C5a were not affected by cyclosporines, and they did not inhibit O2- formation and exocytosis induced by platelet-activating factor and leukotriene B4. Cyclosporines partially inhibited O2- formations induced by NaF and gamma-hexachlorocyclohexane. CsA marginally inhibited PMA-induced O2- formation and lysozyme release. CsA, CsD, and CsH did not inhibit arachidonic acid-induced O2- formation and its potentiation by NaF or stable guanine nucleotides in a cell-free system from DMSO-differentiated HL-60 cells. CsH partially inhibited binding of FML [3H]P to formyl peptide receptors in membranes from DMSO- or dibutyryl cAMP-differentiated HL-60 cells. Our data show that: 1) cyclosporines differentially inhibit activation of human neutrophils; and 2) CsH is, indeed, not immunologically inactive but is a potent and effective inhibitor of FMLP-induced O2- formation. 3) CsH interferes with agonist binding to formyl peptide receptors and in addition, cyclosporines may also act at sites distal to chemoattractant receptors.
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PMID:Differential inhibition of human neutrophil activation by cyclosporins A, D, and H. Cyclosporin H is a potent and effective inhibitor of formyl peptide-induced superoxide formation. 165 6

The hydroxyl radical scavengers dimethylthiourea (DMTU), sodium benzoate, and dimethylsulfoxide (DMSO) were administered to rats before doxorubicin hydrochloride (ADR) (5 mg/kg, IV) to probe the role of free radicals in mediating proteinuria in doxorubicin hydrochloride nephrosis (AN). Because ADR stimulates free radical production, the role of renal glutathione was also evaluated; glutathione metabolism is involved in tissue detoxification processes. DMTU administration to rats with AN caused a significant (p less than 0.01) reduction in their proteinuria after 7 days (52.84 +/- 13.21 mg/24 hours) when they were compared with ADR controls (155.81 +/- 20.16 mg/24 hours). In similar fashion, their urine albumin excretion was also significantly reduced when compared with that of ADR controls (11.13 +/- 2.75 mg/24 hours vs 32.08 +/- 4.14 mg/24 hours; p less than 0.01). DMTU-treated rats also had significantly (p less than 0.001) reduced urinary protein and albumin excretion at 14 days when compared with rats that received ADR alone. The urinary excretion of lysozyme and N-acetyl-glucosaminidase, markers of renal tubular injury, were significantly increased after 7 or 14 days in rats with AN, despite DMTU treatment. Creatinine clearance was significantly reduced (p less than 0.05) in rats receiving ADR alone (0.223 +/- 0.011 ml/min/100 gm) when compared with that in normal controls (0.331 +/- 0.027 ml/min/100 gm) or DMTU-treated rats (0.289 +/- 0.035 ml/min/100 gm). Unlike DMTU, neither sodium benzoate nor DMSO reduced proteinuria in rats with AN.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Amelioration of glomerular injury in doxorubicin hydrochloride nephrosis by dimethylthiourea. 165 68

Pure DMSO (instead of water) is used as the reaction medium for protein separations. It is shown that common extracellular proteins (i) have high solubility in DMSO (1-50 mg/ml), (ii) do not irreversibly inactivate in this solvent, and (iii) can adsorb onto carboxymethyl cellulose in DMSO and be subsequently fully desorbed in this solvent by inorganic salts. Ion-exchange chromatography on this resin in DMSO has been used to purify bovine pancreatic trypsin and to separate it from hen egg-white lysozyme in their mixture. Another approach to protein separation in DMSO, fractional precipitation with ethyl acetate (which does not dissolve proteins), has been verified with a mixture of bovine pancreatic chymotrypsinogen and chicken egg ovalbumin.
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PMID:Protein separation and purification in neat dimethyl sulfoxide. 203 25

The human promyelocytic cell line HL-60, differentiates in response to a variety of agents including dibutyryl cAMP and agents which increase intracellular cAMP concentrations (phosphodiesterase inhibitors, PGE2, and cholera toxin). HL-60 is also known to be rich in H2 -histamine sensitive adenylate cyclase activity. The present study was therefore designed to test the effects of H2-stimulation on growth and differentiation of HL-60 using the potent H2 agonist dimaprit. Dimaprit markedly increased cAMP production in a dose-dependent manner reaching maximal levels after 30-60 minutes. Intracellular cAMP levels decreased thereafter and by 24 hours were approximately 2-3 fold increased above control. Intracellular cAMP levels were not altered by dimaprit (10(-7)M to 10(-4)M) at 4 days in culture compared to either untreated HL-60 cells or dimethylsulfoxide (DMSO) (1.3%) treated cells. While exponential growth was unaltered by dimaprit (10(-7)M to 10(-4)M) as compared to control, dimaprit induced i) morphologic maturation to the myelocyte and metamyelocyte form with no differentiation seen beyond the metamyelocyte even after 6 days in culture, ii) increased NBT reductase activity and iii) dose-dependent increase in lysozyme activity which could be completely blocked by cimetidine, a specific H2 antagonist. Dimaprit-induced differentiation of HL-60 cells was associated with an initial but transient increase in intracellular cAMP production. Maturation beyond the metamyelocyte stage was not observed. Acquisition of NBT reductase and lysozyme activity correlated with morphologic maturation.
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PMID:Effects of dimaprit on growth and differentiation of human promyelocytic cell line, HL-60. 298 4

Recently, a novel approach has been used in the treatment of leukemia: induction of the leukemic cells to undergo terminal differentiation. Based on its in vitro ability to induce differentiation in several myeloid leukemic cell lines, retinoic acid (RA) has been applied clinically in cases of myelodysplastic syndromes and acute myeloid and promyelocytic leukemia. In the present study we have determined in detail the ability of RA to induce expression of granulocytic functions in a human promyelocytic leukemia cell line (HL-60) and compared it with that of dimethylsulfoxide (DMSO). Several granulocytic characteristics (phagocytosis, surface adherence and generation of free radicals in response to phorbol-ester) were induced to the same degree by both agents. Other normal neutrophil functions, including lysozyme accumulation, spontaneous migration, chemotactic activity toward zymosan-activated serum (containing C5a), the peptide N-formyl-methionyl-leucyl-phenylalanine (FMLP) and spontaneous motility in semi-solid medium were induced by DMSO, but they were absent or incompletely expressed in RA-induced cells. In contrast, only RA induced migration toward leukotriene B4 (LTB4). Simultaneous treatment with RA and DMSO proved synergistic with respect to morphological maturation and several functions (e.g. NBT reduction), but complementary stimulation of other activities (e.g. chemotaxis, lysozyme content) could not be demonstrated. Furthermore, characteristics induced by DMSO (i.e., expression of C5a and FMLP receptors and accumulation of lysozyme) were inhibited by the addition of RA.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Expression of granulocytic functions by leukemic promyelocytic HL-60 cells: differential induction by dimethylsulfoxide and retinoic acid. 347 6

12-)-Tetradecanoylphorbol-13-acetate (TPA), the prototype polyfunctional diterpene ester tumor promoter of two-step carcinogenesis in mouse skin, induced differentiation of human promyelocytic leukemia cells (HL-60) in culture. Differentiation of HL-60 cells was characterized by increased phagocytosis, increased lysozyme activity (EC 3.2.1.17) in the growth medium, and changes in morphology to those characteristics of more mature cells resembling macrophages. Many of the cells treated with TPA became aggregated, attaching firmly to culture flasks. The average intracellular myeloperoxidase activity (EC 1.11.1.7) per cell decreased during induction of differentiation by TPA. It was also found that TPA enhanced, rather than inhibited, differentiation of HL-60 cells induced by DMSO. In addition to TPA, several polyfunctional diterpene esters of the tigliane, ingenane, and daphnane type have been tested for their ability to induce morphological and functional changes of HL-60 cells. The activities of the compounds to induce these changes correlated well with their activities as tumor promoters in two-step carcinogenesis in mouse skin. In particular, half the concentrations required for induction of adhesion of the cells to flasks were roughly correlated to the potency of these compounds as tumor promoters. Among the compounds tested, phorbol-12,13-didecanoate (PDD), ingenol-3-hexadecanoate, Pimelea factor P1 and Pimelea factor P2 were as active as TPA, while 4-O-methyl-TPA and 4 alpha-PDD were much less active. Phorbol and ingenol were totally inactive up to a concentrations 10,000-fold higher than that of TPA.
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PMID:Induction of differentiation in human promyelocytic leukemia cells by tumor promoters. 628 Dec 83

With very few exceptions, it has not been possible to grow human myeloid cells for long periods in culture. We have recently developed techniques enabling the long-term in vitro propagation of normal immature myeloid cells from fresh foetal cord blood and monocytes from normal adult peripheral blood, and have utilized these procedures to initiate cultures of fresh peripheral blood leukocytes from leukemic donors. In four of 26 leukemic samples tested, leukocyte replication beyond that obtained in control cultures was observed, and in one of these HL-92, derived from the peripheral blood of a patient with acute myelomonocytic leukemia, the culture has continued to replicate slowly for over 2 years under the special growth conditions. Morphological, cytochemical, immunological and functional studies show that the culture consists predominantly of immature myeloid cells (myeloblasts through to myelocytes) but also contains some mature neutrophils and monocytes. At least a portion of HL-92 cells express Fc and complement receptors, contain histacompatibility locus antigens, including HLA-DR, and release GM-CSA, low levels of PGE and lysozyme. HL-92 cells can be induced with DMSO or RA to differentiate into mature neutrophils (an increase from 20 to 70% of the cell population) as determined by morphology, by an increase in phagocytic cells, and superoxide anion production. Fresh leukocytes from the patient's bone marrow appeared to have a diploid karyotype. However a consistent chromosomal abnormality observed in HL-92 was a deletion in the long arm of chromosome 11 [del(11)(q23)]. This is consistent with recent observations in monocytic leukemia. Since the few other established human myeloid cell lines have various chromosomal abnormalities, and some respond to differentiation inducers, while others do not, there appears to be no detectable common chromosome change required either for in vitro growth of myeloid cells or their response to inducers of differentiation. These cell lines and the application of the techniques described here for the growth of myeloid cells from other leukemic or normal sources should be helpful in the study of normal and leukemic myeloid cell growth and differentiation.
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PMID:Establishment, characterization and differentiation induction of a new human diploid myelomonocytic cell line (HL-92) derived from a patient with acute myelomonocytic leukemia. 696 Dec 68

The thermal denaturation of lysozyme in aqueous sulfoxide solutions (pH 3) was investigated by differential scanning calorimetry (DSC). The sulfoxides employed were dimethylsulfoxide (DMSO), ethylmethylsulfoxide, (DMSO), dimethylsulfoxide (DMSO), and butylmethylsulfoxide (BMSO). The temperature of denaturation, Td, decreased with an increase in the concentration of sulfoxide, the decrease becoming much more pronounced at higher sulfoxide concentrations. The lowering of Td was enhanced by an increase in the hydrocarbon content of the sulfoxide molecule. The enthalpy of denaturation, delta Hd, showed a complex dependence on the solvent composition; the delta Hd first increased with increasing sulfoxide concentration and then started decreasing at different concentrations for each sulfoxide. This behavior is analogous to that with monohydric alcohols, but is different from that with guanidine hydrochloride. These results may be interpreted in terms of the interactions of the sulfoxide added with the protein and with water.
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PMID:Effect of dimethylsulfoxide and its homologues on the thermal denaturation of lysozyme as measured by differential scanning calorimetry. 711 80

The folding of hen egg white lysozyme is complex, involving parallel pathways and distinct folding domains [Radford, S.E., Dobson, C.M., & Evans, P.A. (1992) Nature 358, 302-307]. In the present work the refolding of this protein from two denatured states that have different conformational properties, one generated by the presence of guanidinium chloride (GdmCl) and the other by dimethyl sulfoxide (DMSO), has been examined. Refolding was initiated by rapid dilution and followed by hydrogen-exchange pulse labeling, stopped-flow circular dichroism (CD) in the near-ultraviolet region, and stopped-flow fluorescence experiments. When the final refolding conditions were identical (545 mM GdmCl, 8% (v/v) DMSO, and 20 mM sodium acetate, pH 5.5, 20 degrees C), the folding behavior from the different denatured states monitored by near-UV CD and hydrogen-exchange pulse labeling was indistinguishable. These experiments indicate that the folding process of hen lysozyme is not significantly dependent on the nature of the two denatured states. The complexities in the pathway, therefore, appear to arise from properties of the collapsed state which is formed within the first few milliseconds of refolding. The kinetics of folding were found to be dependent on the concentration of DMSO in the final refolding buffer, although the fundamental properties of the pathway, including the existence of parallel events and distinct folding domains, are preserved under all the conditions studied. Inclusion of DMSO in the refolding buffer increases the rate of formation of native-like structure and of the native state itself. This could result from destablization of species formed early in folding, allowing them to rearrange more rapidly to permit productive folding to proceed. The results indicate that examination of a wide range of conditions will contribute substantially to a more complete understanding of protein folding pathways.
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PMID:Comparison of the refolding of hen lysozyme from dimethyl sulfoxide and guanidinium chloride. 784 31


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