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)

Vasculogenesis depends on autocrine secretion of basic fibroblast growth factor (bFGF) from capillary endothelial cells. Retinoic acid (RA) induced avascular yolk sac (AVY) of mouse embryos of dams given 60 mg/kg of RA orally on Day 8 of gestation and sacrificed 3 days later. We studied the localization and transcriptional expression of bFGF and FGF-receptor (flg), heparin-binding growth factor (HBGF) activity, localization of lysosomal enzymes and alpha 1-antitrypsin (AAT), and electron microscopy of the normal mouse visceral yolk sac (VYS) and AVY. bFGF, which is normally present in the endoderm of the VYS of 8-day-old embryos and in all components of the VYS by Day 11 of gestation, was reduced in the AVY. However, in the presence of bFGF in vitro capillary nets were restored in the AVY. The mRNA for bFGF was not detectable in either VYS or AVY, while flg mRNA was detected equally in both organs in Northern blotting. The characteristic distribution pattern of lysosomal enzymes, acid phosphatase, lysozyme, and cathepsin D, and AAT was altered in the AVY. The level of acid phosphatase and AAT was reduced to 10% in the AVY. Electron microscopy revealed a partial or total loss of lysosomal membranes where the contents of lysosomes fused with adjacent lysosomes and the external organelles. These results suggest that vitelline blood vessels are not developed by endogenous autocrine bFGF but by exogenous transcellular bFGF from absorptive endodermal cells. Retinoic acid does not affect the angiogenic capacity of the VYS mesenchyme but destroys lysosomes, which release hydrolytic enzymes, leading to degradation of AAT in the endodermal cells and then digestion of endocytosed bFGF.
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PMID:Induction of avascular yolk sac due to reduction of basic fibroblast growth factor by retinoic acid in mice. 137 72

According to investigations, it was shown that peripheral blood WBC count increased, percentage of promyelocytes increased, differentiation features emerged, protein kinase C (PK-C) activity elevated, intracellular lysozyme content increased, CFU-F productivity increased and typical t (15; 17) disappeared, when induced differentiation therapy with all trans-retinoic acid (RA) was carried out in patients with acute promyelocytic leukemia. Comparison between RA group and RA+Harringtonin/Ara-C group showed no significant difference in most of the parameters; the curative effect was same in both groups. Complete remission (CR) rate was achieved in 92.6% (25/27 cases) of the patients in the entire group. In order to increase CR rate, prevention and treatment for haemorrhagic complications are critical. Patients with hyperleukocytosis (WBC > or = 100 x 10(9)/L) should be treated with intensive combined therapy as well as aggressive prevention of haemorrhage and pathological changes of lung and brain.
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PMID:[A laboratory and clinical study of induced differentiation therapy by all trans-retinoic acid in acute promyelocytic leukemia]. 142 5

The activities of protein tyrosine kinase and phosphatidylinositol turnover have been found to be associated with cell growth and differentiation. We examined the effects of some inhibitors for these biochemical activities in human myelogenous leukemia cells. Genistein, which is known to inhibit the activities of protein tyrosine kinase, phosphatidylinositol turnover and topoisomerase II, induced nitroblue tetrazolium (NBT) reduction and lysozyme activity in ML-1, HL-60 and U937 cells. Morphological studies showed that genistein-induced differentiation of myeloblastic ML-1 cells into promyelocytes and of promyelocytic HL-60 cells into mature granulocytes. The differentiation-inducing effect of genistein was augmented by addition of 1 alpha,25-dihydroxyvitamin D3 (VD3) or retinoic acid, VD3 being more effective than retinoic acid. Methyl 2,5-dihydroxycinamate, a protein tyrosine kinase inhibitor, had only a weak effect in inducing differentiation of ML-1 cells. On the other hand, psi-tectorigenin was more effective than genistein in inducing the differentiations of ML-1 and HL-60 cells. Psi-tectorigenin is reported to inhibit phosphatidylinositol turnover without inhibiting protein tyrosine kinase. Thus modulation of phosphatidylinositol turnover might be more important than that of protein tyrosine kinase activity for differentiation of some myelogenous leukemia cells.
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PMID:Effects of inhibitors of protein tyrosine kinase activity and/or phosphatidylinositol turnover on differentiation of some human myelomonocytic leukemia cells. 189 51

Two Hodgkin's Reed-Sternberg cell (H-RS) lines, HDLM-1 and KM-H2, have phenotypes and functional properties very similar to those of H-RS cells in tissues. These two types of cells were induced to differentiate with a combination of phorbol ester, retinoic acid, and extracellular matrix. The induced cells displayed the morphology of histiocytes or histiocytelike cells, with a small, round or oval, eccentric nucleus and abundant cytoplasm. In ultrastructural studies, many cytoplasmic projections and rugae were observed. These induced cells exhibited abundant cytoplasmic lysosomal enzymes, such as esterase, acid phosphatase, alpha 1-antitrypsin, or lysozyme. The histiocytic nature of these induced cells was further confirmed by the increased expression of many monocyte/histiocyte markers, including CD11b, CD11c, CD13, CD14, CD15, CD33, CD68, Mac387, and 1E9. In functional tests, the induced cells were shown to produce interleukin-1, tumor necrosis factor, macrophage colony-stimulating factor, and/or prostaglandin E2. Phagocytosis was detected in less than 5% to 10% of the cells when Candida albicans was added to cultures. The results strongly suggest that H-RS cells are related to cells of histiocyte lineage.
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PMID:Cultured Reed-Sternberg cells HDLM-1 and KM-H2 can be induced to become histiocytelike cells. H-RS cells are not derived from lymphocytes. 216 11

The effects of TPA (12-0-tetradecanoylphorbol-13-acetate) and RA (retinoic acid) were investigated on the cell lines HL60 (acute promyelocytic leukemia) and K562 (erythroleukemia) and on cells from patients with several kinds of leukemia. There were 14 cases of acute lymphocytic leukemia (ALL), 2 cases of chronic lymphocytic leukemia (CLL), 23 cases of acute myeloid leukemia (M1-M7), 5 cases of chronic myelocytic leukemia in blast crisis (CML-BC) and 2 mixed leukemias. In almost all of the cases examined, after TPA exposure cells from patients with proven myeloid leukemia became adherent to the substrate, while lymphoid leukemia cells remained in suspension, allowing the differentiation of lymphoid from myeloid blasts. The only exception was in one case of CLL, which had cells that became adherent with long filamental projections. In addition, increased phagocytosis following TPA exposure permitted characterization of M7 as this was the only myeloid leukemia negative for phagocytosis. Further discrimination between the subtypes of myeloid leukemia could be based on the increased lysozyme production seen after TPA in M4 and M5. Esterase positivity allowed the discrimination of M1 cells, which were negative before and after TPA treatment. In agreement with the results of other authors, TPA and RA led to independent ways of differentiation, granulocytic-like lineage and monocytic-like cells being favored by RA and TPA, respectively. The capacity of the same cell to differentiate into more than one lineage, depending on whether RA or TPA was used, was only seen in the present study with M3 cells.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Myeloid leukemia differentiation by phorbol ester and retinoic acid: a practical approach. 223 Nov 80

The interaction of granulocyte-colony stimulating factor (G-CSF) and retinoic acid (RA) in proliferation and differentiation of acute promyelocytic leukemia (APL) cells was examined. G-CSF stimulated proliferation of APL cells at concentrations of 0.1 to 50 ng/ml in a dose dependent manner. More than 10(-8) M RA induced granulocytic differentiation of APL cells. Although G-CSF induced lysozyme activities in APL cells, it alone did not induce terminal differentiation of APL cells. G-CSF significantly enhanced the RA-induced granulocytic differentiation of APL cells in vitro. Enhancement by G-CSF was not due to the prolongation of survival of RA-induced differentiated cells, but the differentiation-inducing effects of G-CSF might be evident only in the presence of RA. Since G-CSF has a potential to induce the granulocytic differentiation of myeloid leukemia cells, G-CSF in combination with RA may be applicable in differentiation induction therapy for some types of myeloid leukemia.
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PMID:Granulocyte-colony stimulating factor and retinoic acid cooperatively induce granulocyte differentiation of acute promyelocytic leukemia cells in vitro. 248 63

Differentiation-inducing agents have recently been applied clinically in various myeloproliferative diseases, based on their in vitro ability to induce differentiation in myeloid and monocytic cell lines. In this study we compared the abilities of two agents, dibutyryl cyclic AMP (DBcAMP) and retinoic acid (RA) to induce monocytic functions in the human histiocytic lymphoma cell line U937. Both agents produced similar induction of phagocytosis and reduction of nitroblue tetrazolium (NBT). Other monocytic functions, including accumulation of lysozyme, spontaneous and directed migration toward zymosan-activated serum (ZAS), the chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine (FMLP) and leukotriene B4 (LTB4) were induced by DBcAMP, while RA induced migration toward LTB4 only. Simultaneous treatment with both inducers proved synergistic only with respect to phagocytosis. NBT reduction and migration toward FMLP and LTB4 were unchanged, while migration toward ZAS and lysozyme accumulation were suppressed by the addition of RA. The results suggest that the inducer affects the expression of cellular functions and characteristics specific to a particular lineage. In addition, the data presented indicate that the U937 cell line may serve as an excellent model system for the study of the regulation and mechanisms of chemotactic receptor expression in monocytes.
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PMID:Differential induction of monocytic functions by dibutyryl cyclic AMP and retinoic acid in a human monoblast cell line U937. 285 81

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-O-Tetradecanoylphorbol 13-acetate (TPA), phorbol 12,13-diacetate and phorbol 12,13-didecanoate were all potent inducers of thromboplastin activity in human monocytes in vitro, whereas 4 alpha-phorbol 12,13-didecanoate and 4 alpha-phorbol had no such effect. A concomitant increase in titrable apoprotein III antigen was found (apoprotein III is the protein component of thromboplastin). The increase was inhibited by cycloheximide and actinomycin D and partly by alpha-amanitin. The increase of thromboplastin activity was therefore most likely due to synthesis de novo of apoprotein III. The response was approximately halved in the absence of serum or Ca2+. Retinol had a weak inhibitory effect, and retinoic acid was inhibitory only at concentrations that also induced signs of cytotoxicity. TPA caused an initial rise in monocyte cyclic AMP concentration of about 90-120 min duration. No increase in 45Ca2+ influx was induced over 2 h. Good correlation exists between induction of apoprotein III synthesis in monocytes in vitro and mouse skin-tumour promotion in vivo by the various phorbol derivatives. Substances inactive in tumour promotion do not induce the synthesis of apoprotein III. General activating and cytotoxic effects of TPA were monitored by determining release of lysozyme, beta-glucuronidase and lactate dehydrogenase.
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PMID:Phorbol esters induce synthesis of thromboplastin activity in human monocytes. 627 36

1 alpha, 25-Dihydroxyvitamin D3 [1,25-(OH)2D3] was shown to induce a high phagocytic capability in the macrophage-like murine tumor cell line P388D1. Induction of phagocytic capability by 1,25-(OH)2D3 was dose-dependent in the range of 0.2 to 5.0 ng/ml, required the continuous presence of the secosteroid in culture, and was reversible. 25-Hydroxyvitamin D3 was an effective inducer only at about 500 ng/ml, while 24R,25-dihydroxyvitamin D3 was ineffective. The induction of the high phagocytic capability was neither accompanied by increased synthesis of lysozyme nor closely associated with an inhibitory effect on cellular proliferation. P388D1 cells bound (without ingestion) nonopsonized sheep erythrocytes (sheep RBC), and the binding increased in 1,25-(OH)2D3-treated cells. Fc-receptor-mediated binding of immunoglobulin G-coated sheep RBC was not modulated in 1,25-(OH)2D3-treated cells, but the cells acquired an Fc-receptor-mediated phagocytic capability that was expressed only when preformed P388D1-sheep RBC rosettes were further exposed to immunoglobulin G. Several differentiation agents of myeloid leukemia cells (including dexamethasone) were not effective in inducing the high-phagocytic phenotype, while retinoic acid was very effective. Different myeloid or macrophage-like tumors (WEHI-265, J774.2, PU-5, and WEHI-3) were variable in their response to 1,25-(OH)2D3.
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PMID:Induction of a high phagocytic capability in P388D1, a macrophage-like tumor cell line, by 1 alpha, 25-dihydroxyvitamin D3. 654 2


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