Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.3.1 (alkaline phosphatase)
47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A cell line, called MG-63.3A, was selected for its resistance to detachment from cell culture by a synthetic peptide containing the fibronectin cell-attachment sequence, Arg-Gly-Asp-Ser. The mechanism of this resistance is probably the 6-fold overproduction of the cell surface fibronectin receptor in MG-63.3A cells (Dedhar et al, J. Cell. Biol. 105, 1175-1182, (1987]. Compared to the parental, tumorigenic MG-63 cells, the non-tumorigenic MG-63.3A cells display strikingly different properties. These include an altered morphology, a slower proliferation rate, ability to form a calcified matrix in vitro, increased synthesis of type I collagen and expression of bone type alkaline phosphatase activity. Studies with purified growth factors indicate that the MG-63 and MG-63.3A cell lines respond to differentially to growth factors; the growth of MG-63 cells if stimulated by PDGF and GM-CSF and inhibited IL-1 beta, whereas the growth of MG-63.3A is unaffected by GM-CSF and IL-1 beta but is stimulated by PDGF and estradiol. We conclude from these data that the MG-63.3A cells may represent a more differentiated cell type with osteoblast-like properties. Studies are currently underway to further characterize, by electron microscopy, the calcified matrix formation by MG-63.3A cells.
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PMID:The osteoblast-like differentiated phenotype of a variant of MG-63 osteosarcoma cell line correlated with altered adhesive properties. 253 54

We have previously reported that the J774A.1 macrophage-like tumor cell line produces two potent monokines which stimulate the growth of osteoblasts and chondrocytes. These growth factors, which have an affinity for heparin-agarose, have been termed HEP I (a 30 Kd PDGF-like molecule) and HEP II (an approximately 20 Kd molecule), respectively, based on their elution profile. Unlike HEP I, HEP II does not stimulate the growth of fibroblasts. Extensive biological and chromatographic studies disclosed that HEP II appears to be a unique bone cell mitogen unlike any known growth factor, including the FGFs, IL-1s, and TNFs, EGF, IGF-I and -II, TGF-beta, beta 2 microglobulin, G-CSF, CSF-1 and GM-CSF. To characterize more fully the effects of the macrophage-derived monokines on osteoblast growth and function, clones were derived from calvaria explant cultures. Two clones, SDFRC-2.05 and SDFRC-3, were developed and found to exhibit osteoblastic characteristics, including high levels of alkaline phosphatase, synthesis of type I but not type III collagen, and an increased intracellular cAMP production in response to PTH. The SDFRC-3 cells exhibited a polygonal morphology like that of the explant-derived cells while SDFRC-2.05 cells exhibited a more fibroblastic morphology. When tested on the explant cultures and clones, HEP I and HEP II were found to stimulate DNA synthesis and increase protein per culture, but decreased alkaline phosphatase activity. Clone SDFRC-3 was found to be more responsive to HEP II than clone SDFRC-2.05. Both monokines were found to be more potent mitogens for bone cells than TGF-beta. HEP II, but not HEP I or TGF-beta, induced a transformation of bone cells from a polygonal to a fibroblastic morphology, suggesting the induction of migration prior to proliferation. Thus, macrophages may be responsible not only for bone repair but also for ensuring the linkage of bone formation to resorption during physiological remodeling.
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PMID:Monokines produced by macrophages stimulate the growth of osteoblasts. 263 Jan 69

Studies on blood serum from mammary carcinoma (MC) hosts, which promoted gamma-glutamyl transpeptidase (GGT) expression by normal rat bone marrow cells in liquid culture, were extended to various granulocyte-macrophage colony stimulating factors (CSFs). GGT concentration per cell was found to increase (without change in total cell number) by incubation for 48 h with purified CSF-2 gamma and CSF-1 (but not interleukin-3), with human giant cell elaborated GM-CSF and L-cell conditioned medium, as well as with the 3 MC preparations (host serum, MC extract and MC conditioned medium). GGT-inducing ability (per milligram protein) ranked the 7 preparations in the same order as did their proliferative effect (number of colonies per milligram protein) in the standard mouse bone marrow agar culture system. The quantitative correlation between these two kinds of activities (linear for their logarithmic values) was highly significant, r = 0.976, p less than 0.001. The alkaline phosphatase concentration of bone marrow cells in liquid culture was also increased in the presence of the same 7 preparations, and this again was proportional (r = 0.985, p less than 0.001) to their colony stimulating potential.
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PMID:Enhancement of gamma-glutamyl transpeptidase expression in bone marrow cells by colony stimulating factors. 290 68

The properties of a cell line (H-1) derived from the adherent layer of a murine marrow liquid culture system are described in detail. Morphologically the cells are of a fibroblastic nature, having none of the specialized structures found in endothelial cells or macrophages. They have neither Fc receptors nor peroxidase activity confirming that they are not mononuclear phagocytes. However, they possess alkaline phosphatase and acid phosphatase, synthesize collagen, and are weakly phagocytic. Adventitial reticular cells in bone marrow, which have a close association with all developing hemopoietic cells, possess these properties. It is suggested that the H-1 cell line, which produces colony stimulating factor (GM-CSF), is derived from the adventitial reticular cell of the marrow.
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PMID:Characterization of a murine cell-line derived from cultured bone marrow stromal cells. 715 80

Bone remodelling is regulated at the local level by an incompletely elucidated cytokine network. In the present study we have determined the effect of interleukin-4 (IL-4), a cytokine produced by T lymphocytes and other cells, on the activity of murine osteoblasts. IL-4 (0.1-10 ng/ml) did not influence the proliferation rate of the osteoblast-like cell line MC3T3, but inhibited the expression of alkaline phosphatase. In long-term cultures supplemented with ascorbic acid and glycerophosphate such an effect was accompanied by a retardation of matrix mineralization. IL-4 also stimulated M-CSF expression by MC3T3 cells, both at the RNA and bioactivity levels. However, no stimulation of IL-1, IL-6, GM-CSF or PGE2 production was observed. An IL-4-induced inhibition of alkaline phosphatase expression and retardation of mineralization was also found in cultures of primary osteoblast-like cells isolated from neonatal mice calvariae. These results suggest that IL-4, probably released by cells within the bone marrow, may locally influence the activity of bone-forming cells.
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PMID:Interleukin-4 as a bone regulatory factor: effects on murine osteoblast-like cells. 754 94

Osteoblasts are involved in the bone resorption process by regulating osteoclast maturation and activity. In order to elucidate the mechanisms underlying osteoblast/preosteoclast cell interactions, we developed an in vitro model of co-cultured human clonal cell lines of osteoclast precursors (FLG 29.1) and osteoblastic cells (Saos-2), and evaluated the migratory, adhesive, cytochemical, morphological, and biochemical properties of the co-cultured cells. In Boyden chemotactic chambers, FLG 29.1 cells exhibited a marked migratory response toward the Saos-2 cells. Moreover, they preferentially adhered to the osteoblastic monolayer. Direct co-culture of the two cell types induced: (1) positive staining for tartrate-resistant acid phosphatase in FLG 29.1 cells; (2) a decrease of the alkaline phosphatase activity expressed by Saos-2 cells; (3) the appearance of typical ultrastructural features of mature osteoclasts in FLG 29.1 cells; (4) the release into the culture medium of granulocyte-macrophage colony stimulating factor. The addition of parathyroid hormone to the co-culture further potentiated the differentiation of the preosteoclasts, the cells tending to fuse into large multinucleated elements. These in vitro interactions between osteoblasts and osteoclast precursors offer a new model for studying the mechanisms that control osteoclastogenesis in bone tissue.
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PMID:Functional and structural interactions between osteoblastic and preosteoclastic cells in vitro. 762 25

We have investigated the effect of a number of cytokines on the human acute myelomonocytic leukemic cell line, ML-1. The differentiation inducing effects of interleukins (IL-1 beta, IL-3 and IL-6), colony stimulating factors (GCSF and GMCSF), TNF, LIF and IFNg, were studied either individually or in combination. Criteria for monocytic differentiation were as follows: an increase in the percentage of cells reducing nitroblue tetrazolium (NBT) salt, an increase in the alkaline phosphatase activity as well as the appearance of macrophagic phenotype. Among all the cytokines tested, only TNF was found to induce differentiation and to inhibit growth of ML-1 cells. IL-3, IL-6, interferon gamma, GCSF and to a smaller extent IL-1 beta and GMCSF synergized the differentiation inducing activity of TNF.
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PMID:Comparative analysis of the effects of recombinant cytokines on the growth and differentiation of ML-1, a human myelogenous leukemic cell line. 768 36

Short-term cultures of purified murine trophoblast were used to investigate the potential trophic effects of a number of cytokines. Both granulocyte-macrophage colony stimulating factor (GM-CSF) and colony stimulating factor-1 (CSF-1) increased [3H]thymidine (TdR) uptake (3-8 times control values) by trophoblast harvested from placentae on day 12 or 14 of pregnancy. In contrast, interleukin-3 (IL-3) had only a mild stimulatory effect ([3H]TdR uptake 1.5 times control), and IL-2 did not alter the level of DNA synthesis in these cells. Immunocytochemical analysis confirmed that the cells engaged in DNA synthesis were cytokeratin-positive trophoblast cells and revealed that these cells predominantly bore markers (alkaline phosphatase, transferrin receptors) characteristic of trophoblast cells from the placental labyrinth. The increased DNA synthesis observed after exposure to GM-CSF or CSF-1 was not associated with a change in the proportion of nuclei involved in synthesis, nor did it result in significantly increased trophoblast cell numbers in the cultures. These findings suggest that DNA-synthesizing trophoblast cells were not proliferating, but were more likely engaged in endoreduplicative cycles leading to the formation of terminally differentiated trophoblast giant cells. These results caution against the presumption of proliferation when measuring [3H]thymidine incorporation by placental or trophoblast cells in standard in vitro cultures. In addition, taken together with the reports of high levels of CSF-1 in the pregnant uterus and the expression of the CSF-1 receptor on placental trophoblast cells, they suggest that the hemopoietic cytokines may play a role in the differentiation and/or function of trophoblast cells in the developing murine placenta.
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PMID:GM-CSF and CSF-1 stimulate DNA synthesis but not cell proliferation in short-term cultures of mid-gestation murine trophoblast. 804 Aug 36

The mRNA expression of alkaline phosphatase (ALP), myeloperoxidase (MPO), defensin and G-CSF receptor (G-CSFR) in bone marrow cells of normal individuals and myeloid disorders, with or without in vitro stimulation by myeloid cell growth factors, i.e. G-CSF, GM-CSF and IL-3, were examined as markers for myeloid cell differentiation in both mononuclear cell (MNC) and polymorphonuclear cell (PMN) fractions. Without any stimulation, ALP mRNA was expressed only in PMNs, G-CSFR mRNA in PMNs were expressed stronger than in MNCs; both MPO and defensin mRNA were expressed to the same degree in both fractions. With stimulation, the ALP mRNA expression in both fractions was strongly enhanced by G-CSF, but the expression was inhibited by GM-CSF and/or IL-3. MPO mRNA expression was stimulated by G-CSF and/or GM-CSF in MNCs. G-CSFR mRNA expression was enhanced by G-CSF in both fractions. Defensin mRNA expression was inhibited by G-CSF. In cases of myelodysplastic syndrome and chronic myelogenous leukaemia which display a suppressed maturation of myeloid cells, our results demonstrated an almost normal response to these growth factors. Our results suggest that studies on these myeloid marker mRNA expressions would provide more knowledge about the differentiation state and cytokine reactivity of myeloid cells in normal individuals as well as various disorders.
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PMID:Effects of myeloid cell growth factors on alkaline phosphatase, myeloperoxidase, defensin and granulocyte colony-stimulating factor receptor mRNA expression in haemopoietic cells of normal individuals and myeloid disorders. 856 17

Granulocyte colony-stimulating factor (G-CSF) was administered at a dose of 7.5 or 10 micrograms/kg s.c. once daily for 6d (days 1-6) to two groups consisting of eight and six healthy volunteers. The administration of G-CSF resulted in a rapid decrease in neutrophil counts and serum levels of the secondary granule protein, human neutrophil lipocalin (HNL) after 30 min, followed by a recovery and gradual increase within 180 min. The number of circulating neutrophils and plasma and serum levels of neutrophil secondary granule proteins were dramatically elevated on day 2 (1 d after the administration of G-CSF) and stayed so until day 7. The plasma levels of HNL and lactoferrin (LF) showed a biphasic pattern with peaks at day 2 and days 5-7, and remained highly elevated at day 12. The serum levels of HNL and LF increased rapidly (about 8-fold and 6-fold, respectively) on day 2 and stayed elevated until day 7, subsequently returning to baseline levels. At day 5, neutrophil release induced in vitro by f-MLP was significantly enhanced. The cellular contents of HNL and LF were reduced to about 50% of levels before G-CSF administration at day 5. The release of lactoferrin and HNL, but not of myeloperoxidase (MPO), was slightly enhanced after preincubation of isolated normal neutrophils with G-CSF in vitro, but no obvious release of these proteins was observed with G-CSF alone. The administration of G-CSF resulted in a dramatic increase in the alkaline phosphatase (AP) activity in the plasma membrane, with maximal activity occurring at day 5. Furthermore, during administration of G-CSF, TNF-alpha in plasma increased about 25-fold. TNF-alpha started to rise at day 2 and peaked at day 6. After discontinuation of G-CSF the levels of TNF-alpha gradually decreased. The elevated levels of TNF-alpha (tumour necrosis factor-alpha) were temporally correlated to the other signs of neutrophil activation. GM-CSF and IL-8, however, were not detected in plasma. Our data suggest that G-CSF affects the neutrophils not only directly but also indirectly by the induction of the production of other cytokines such as TNF-alpha.
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PMID:The effect of granulocyte colony-stimulating factor (G-CSF) on the degranulation of secondary granule proteins from human neutrophils in vivo may be indirect. 865 73


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