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:3.1.3.1 (alkaline phosphatase)
47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A new cell line (SARG) was established from a human radiation-induced osteosarcoma (OSA). It showed an epithelial-like morphology with polymorphous and sometimes bizarre nuclei. SARG had an osteoblastic differentiation pattern: almost 100% of the cells were positive for alkaline phosphatase, type I and III collagens and osteonectin. The expression of class I HLA antigens was detectable even after 40 in vitro passages. The expression of MHC antigens was greatly increased after in vitro treatment with interferon gamma (IFN-gamma), whereas interferon alpha (IFN-alpha) and tumor necrosis factor alpha (TNF-alpha) increased the expression of class I antigens, but not of class II antigens. SARG was tumorigenic after subcutaneous injection in nude mice. Experimental metastases were never detected.
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PMID:SARG: a new human osteosarcoma cell line. Expression of bone markers and of major histocompatibility antigens. 162 59

Since patients with primary biliary cirrhosis (PBC) have evidence of abnormal function of the immune system, we evaluated production of various cytokines by peripheral blood mononuclear cells (PBMCs) and monocytes from patients with this disease, using an enzyme-linked immunosorbent assay. The mean amounts of production of tumor necrosis factor alpha(TNF alpha), interleukin 1 beta (IL1 beta), and interferon-gamma (IFN-gamma) by PBMCs from patients with PBC tended to be increased in cultures in the presence of stimulating agents in comparison with controls, but there was no significant difference because of a wide scatter of results. Monocytes from PBC patients also tended to produce higher amounts of TNF alpha and IL1 beta than control monocytes did, although the percentage of monocytes in PBMCs was similar in PBC and controls. A significant correlation was found between TNF alpha production and IL1 beta production in PBC patients. The number of TNF alpha or IFN-gamma positive infiltrating mononuclear cells detected by immunohistochemical staining in liver biopsy sections correlated with the production of these cytokines by PBMCs in vitro. However, cytokine production did not correlate with serum biochemical or hepatic histologic findings, except for serum alkaline phosphatase values. In patients with type B chronic active hepatitis, IL1 beta and IFN-gamma production was similar to controls, while TNF alpha production tended to be enhanced. Thus the cytokines studied here may play some role in the pathogenesis of PBC.
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PMID:Production of tumor necrosis factor, interleukin 1, and interferon-gamma by peripheral blood mononuclear cells from patients with primary biliary cirrhosis. 211 48

Recent studies have suggested that interleukin-1 or tumor necrosis factor-stimulated bone resorption is mediated by osteoclast-activating factor elaborated by osteoblastic cells. Since recombinant interferon gamma inhibits stimulation of bone resorption by these cytokines, we examined here the effects of recombinant human interferon gamma (rhIFN-G) on DNA synthesis and alkaline phosphatase (ALP) activity of a human osteoblastic osteosarcoma cell line, SaOS2, under preconfluent culture conditions. Addition of rhIFN-G to the cells markedly inhibited their DNA synthesis and ALP activity in a dose-dependent fashion. However, the inhibition was not dependent on the culture time. The highest inhibitory effect was observed in 10% serum-containing culture medium. The inhibitory effect on DNA synthesis was not eliminated by addition of indomethacin, a cyclooxygenase inhibitor. Furthermore, combination of rhIFN-G and recombinant human tumor necrosis factor alpha inhibited their DNA synthesis and the ALP activity in synergistic fashion. Therefore, these data suggest that rhIFN-G is a potent inhibitor for human osteoblastic cells.
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PMID:[Inhibitory effect of recombinant human interferon gamma on human osteoblastic osteosarcoma cells (SaOS2)]. 251 49

The purpose of this investigation was to reveal the mechanism of differentiation of osteoclast (OC) induced by mechanical stress in long bone cultivation of new born rats. A long bone was loaded with 30 gf of continuous compressive force and cultured for 5 days in CO2 incubator. Numbers of OC increased in the long bone were counted after H-E staining and compared with the control. The study was dealt with the effects of recombinant tumor necrosis factor alpha (rTNF alpha), recombinant interleukin-1 beta (rIL-1 beta), prostaglandin E2 (PGE2) and the co-cultivation of osteoblast (OB) originated from new born rat calvariae, as to differentiation of OC. Since the bone remodeling was interacted with OB and bone marrow (BM) cells, the activity of alkaline phosphatase (ALPase) was also investigated for OB in co-cultivation with BM cells originated from new born rat long bones. In the region of diaphysis of a long bone loaded with compressive force, the bend of trabecular bones was noticed after 3 days incubation. Also, the enrichment of monocyte-macrophage (Mo-M phi) lineage cells was noticed along the trabecular bones. After 5 days incubation, the increase of the number of OC was specifically recognized. The increase of the number of OC was shown in medullary cavity of the long bone by addition of rTNF alpha to the culture medium, but any synergistic effect was not shown with the treatment of rTNF alpha and compressive force to the increase of the number of OC. Furthermore, the increase of the number of OC induced by compressive force did not suppressed by addition of anti-TNF serum. Under the treatment of rIL-1 beta or PGE2, OC slightly increased in the long bone when loaded by compressive force, but the treatment of indomethacin did not suppress it completely. However, the increase of OC in the long bone loaded by compressive force was clearly inhibited in co-cultivation with OB. On the other hand, the activity of ALPase of OB was markedly abated in co-cultivation with BM cells. These results indicated that the mechanism of differentiation of OC induced by mechanical stress was different from that induced by the general inflammation. Results also indicated that it was controlled mainly by the factor(s) or interaction between BM cells and OB and was associated with Mo-M phi lineage cells.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[Study of bone remodeling mechanism induced by mechanical stress. Differentiation of osteoclasts induced by compressive force in newborn rat cultured long bone]. 264 Sep 33

To elucidate the mechanism of tumor necrosis factor alpha (TNF-alpha)-induced bone resorption, the effects of recombinant human TNF-alpha on mouse osteoblast-like cells (MC3T3-E1) were studied. TNF-alpha stimulated MC3T3-E1 cells to produce prostaglandin E2 (PGE2) and macrophage colony stimulating activity (M-CSA) in a dose-dependent manner. TNF decreased alkaline phosphatase (AL-P) activity of MC3T3-E1 cells. These TNF effects were observed at 1 ng/ml (approximately 6 X 10(-11)M). The inhibitory effect on AL-P activity was reversible and the cell growth of MC3T3-E1 cells was only slightly affected by TNF. These findings suggest that both PGE2 and M-CSA stimulated by TNF-alpha are possibly involved in osteoblast-mediated osteoclastic bone resorption, whereas inhibition of AL-P activity may lead to a decrease in bone formation.
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PMID:Tumor necrosis factor type alpha (cachectin) stimulates mouse osteoblast-like cells (MC3T3-E1) to produce macrophage-colony stimulating activity and prostaglandin E2. 349 91

This study examines the molecular mechanisms of interaction between tumor necrosis factor alpha (TNF alpha) and retinoic acid on the expression of the alkaline phosphatase gene by rat clonal preosteoblastic cells. In this cell line, alkaline phosphatase mRNA was not constitutively expressed but was progressively induced by treatment with 1 microM retinoic acid, detectable by 6 h. Combining retinoic acid with 0.6 nM TNF alpha resulted in alkaline phosphatase mRNA appearing by 2 h, as well as enhanced expression above that observed with retinoic acid alone at 6, 12, and 24 h. Nuclear run-on analysis showed constitutive transcription of the alkaline phosphatase gene in control and TNF alpha-treated cells. At 4 h, retinoic acid, alone or combined with TNF alpha, increased alkaline phosphatase gene transcriptional rate by 2-fold. However, at 24 h, while no retinoic acid effect was retained, retinoic acid plus TNF alpha resulted in a 5-fold increase in alkaline phosphatase transcriptional rate. Examination of the distribution of nuclear alkaline phosphatase mRNA demonstrated that pre-spliced precursor mRNA was localized to the nuclear matrix in control and all treatment groups. Retinoic acid caused a time-dependent accumulation of mature, spliced alkaline phosphatase mRNA located in the non-matrix and cytoplasmic fractions, implying a post-transcriptional action of retinoic acid in nuclear processing and nucleocytoplasmic transport. Adding TNF alpha with retinoic acid greatly enhanced this effect, which was observed after 4 h, prior to any detectable interaction between TNF alpha and retinoic acid on gene transcription. In sharp contrast, only a negligible amount of nuclear processing occurred in control and TNF alpha-treated cells. This study reveals distinct interactions between TNF alpha and retinoic acid at post-transcriptional as well as transcriptional levels to regulate expression of the alkaline phosphatase gene in preosteoblasts.
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PMID:Tumor necrosis factor alpha facilitates nuclear actions of retinoic acid to regulate expression of the alkaline phosphatase gene in preosteoblasts. 772 5

We report a novel vector system suitable for the efficient preparation of alkaline phosphatase (PhoA)-labelled antibody Fab fragments in Escherichia coli. The previously described pGE20 vector used for the functional expression of truncated heavy (Fd) and light (L) chains of Fab into the bacterial culture medium was modified by inserting the E. coli PhoA coding region 3' to the Fd cloning sites. The secreted Fd-PhoA fusions and L proteins were found to be disulfide linked and Fab-PhoA complexes, prepared with IgG1 antibodies recognizing specifically human tumor necrosis factor alpha, were shown to be useful for the rapid detection of antigen. When an additional short peptide was interposed between the Fd and PhoA domains, nearly all of the recombinant Fab-PhoA conjugates present in the culture supernatant retained both antigen binding and enzymatic activity. A method for the detection and selection of bacterial colonies expressing bifunctional hybrid molecules of desired antigen specificity was also developed. Taken together, the systems described permit the generation and production of Fab-PhoA conjugates in E. coli, which can replace conventionally prepared PhoA-labelled antibodies in appropriate immunoassays.
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PMID:Application of an alkaline phosphatase fusion protein system suitable for efficient screening and production of Fab-enzyme conjugates in Escherichia coli. 776 23

We examined the effect of tumor necrosis factor alpha (TNF-alpha), interleukin 1 beta (IL-1 beta) and IL-6 on alkaline phosphatase (ALP) and osteocalcin (OC) production, calcification and calcium (Ca) release in human cultured osteoblastic cells established from human periosteum. The cells were cultured with varying concentrations of cytokines for three days. TNF-alpha and IL-1 beta significantly inhibited ALP production, decreased cellular Ca content, and significantly enhanced 45Ca release in human osteoblastic cells. IL-6, on the other hand, significantly suppressed 45Ca release from the osteoblastic cells. Any one of these cytokines did not influence the production of OC by the osteoblastic cells. The results obtained suggest that TNF-alpha and IL-1 beta may inhibit bone formation and calcification and promote bone resorption, while the effects of IL-6 on osteoblastic cells may be a little different from those of TNF-alpha or IL-1 beta. Cytokine-dependent these effects on the osteoblastic cells may be one of the mechanisms by which bone loss occurs in patients with rheumatoid arthritis.
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PMID:[Inhibitory effects of cytokines on human osteoblastic cells]. 802 Aug 64

Immobilization induces abnormal bone metabolism and rapid decalcification. Measurements of bone mineral content disclosed rapid decalcification, especially in lumbar vertebral and metacarpal bones in our short-term 20-day bed rest study. Many factors could contribute to the marked demineralization. The activities of osteoclasts and osteoblasts were studied by following serum levels of tartrate-resistant acid phosphatase and alkaline phosphatase, biomarkers for osteocyte activity. There were no alterations in these enzymes during bed rest. However, urinary excretion of pyridinium cross-links, resorption markers of bone matrix itself, increased by day 10 with subsequent decrease at day 20. So decalcification was induced without any relation to osteoclast activity. As cytokines strongly modulate the function of osteoclasts, peripheral monocyte release of interleukin 1 alpha and tumor necrosis factor alpha were assayed to determine the contribution to this rapid demineralization. Cytokines were released transiently by day 7 and later rapidly decreased. However, there was no correlation between cytokine release and bone matrix resorption.
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PMID:Metabolic turnover of bone and peripheral monocyte release of cytokines during short-term bed rest. 804 23

Lipopolysaccharide (LPS) administration to mice elicited the activation of nuclear factor kappaB (NF-kappaB) in several tissues including liver and macrophages. Maximal activation was observed 1 h after treatment but declined at 3 and 6 h. The levels of IkappaBalpha and IkappaBbeta were analyzed during this period in an attempt to correlate NF-kappaB activity with IkappaB resynthesis. Degradation of IkappaBalpha was very rapid and was followed by recovery 1 h after LPS administration. IkappaBbeta degradation, which has been associated with persistent NF-kappaB activation, was complete at 1 h. However, a rapid recovery of IkappaBbeta in these tissues was observed at 3 h in parallel with the abrogation of NF-kappaB activity. Immunolocalization of newly synthesized IkappaBbeta by confocal microscopy revealed its preferential accumulation in the cytosol. Analysis of IkappaBbeta by Western blot using high resolution polyacrylamide gel electrophoresis showed the presence of two bands in cytosolic extracts of LPS-treated macrophages at 3 h, but only one band with the same mobility as the control was detected at 6 h. Moreover, treatment of extracts of resynthesized IkappaBbeta with alkaline phosphatase resulted in the accumulation of the protein of slightly higher electrophoretic mobility, indicating the prevalence of a rapid phosphorylation of the newly synthesized IkappaBbeta. At the mRNA level, up-regulation of IkappaBbeta was observed in macrophages stimulated for 1 h with LPS. When the effect of pro-inflammatory cytokines was investigated, tumor necrosis factor alpha, but not interleukin-1 or interferon-gamma, promoted an important degradation of IkappaBbeta followed by an increase in the mRNA at 1 h. These results suggest the existence of LPS- and tumor necrosis factor alpha- specific pathways involved in a rapid IkappaBbeta degradation and resynthesis and might explain the transient period of activation of NF-kappaB in these tissues upon stimulation with these factors. This rapid control of NF-kappaB function may contribute to the attenuation of the inflammatory response of these cells.
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PMID:Rapid Up-regulation of IkappaBbeta and abrogation of NF-kappaB activity in peritoneal macrophages stimulated with lipopolysaccharide. 928 99


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