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)

The effect of sodium pentosan polysulphate (SPP) was investigated in calcium oxalate stone forming rats with respect to the urinary excretion of certain risk factors and enzymes. Calcium oxalate stones were induced by feeding 3% w/w sodium glycollate to the rats. Urinary calcium, oxalate, phosphorus and uric acid levels were increased in stone formers. In contrast magnesium excretion was low in this group. SPP treatment lowered oxalate and calcium levels in both controls and experimental animals. Magnesium levels were increased moderately. Increased excretion of urinary enzymes--LDH, alkaline phosphatase, gamma-GT and beta glucuronidase--in calculogenic rats indicates membranuria and damage to proximal tubules during stone formation. Decreased pyrophosphatase activity was observed in glycollate fed rats. SPP treatment decreased the excretion of the above enzymes in the treated groups. Stone formers exhibited decreased LAP and fibrinolytic (urokinase) activities. SPP being associated with fibrinolytic properties, increased the activities of the above two enzymes to that of control levels in calculogenic rats.
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PMID:Alterations in some risk factors and urinary enzymes in urolithiatic rats treated with sodium pentosan polysulphate. 768 93

Inflammatory cytokines like interleukin-1 (IL-1) and tumor necrosis factor-alpha (TNF-alpha) are linked to abnormal cartilage and bone loss in a variety of pathological conditions. We have investigated the effect of TNF-alpha on the synthesis and/or steady-state mRNA levels of collagen, alkaline phosphatase (ALP), plasminogen activators (PAs) and their inhibitor PAI-1, and collagenases (MMPs) and their inhibitor TIMP-1 by human osteoblastic, HOS TE85, cells in monolayer cultures. HOS TE85 cells possess approximately 2000 TNF-alpha receptors per cell with a Kd value of 0.67 nM and receptor of approximately 60 kDa. TNF-alpha enhances urokinase-plasminogen activator (u-PA) activity and steady-state mRNA levels twofold without affecting tissue-plasminogen activator (t-PA) or PAI-1. The increase in u-PA mRNA is due to enhanced transcription of this gene. mRNA levels or activities of collagenase 1 (MMP-1), 72- and 92-kDa gelatinases (MMP-2 and MMP-9) are also nearly doubled with little change in the level of expression of TIMP-1. TNF-alpha does not significantly affect the activity or mRNA levels of ALP. TNF-alpha decreases collagen as well as general protein synthesis. However, the steady-state mRNA for the alpha 2 chain of collagen type I is increased three- to fourfold. These results show that TNF-alpha may increase pathological bone turnover by enhancing the rate of transcription of proteases capable of degrading the nonmineralized osteoid layer and decelerating the maturation of the extracellular matrix formed by osteoblasts.
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PMID:Modulation of proteases and their inhibitors in immortal human osteoblast-like cells by tumor necrosis factor-alpha in vitro. 808 23

We previously reported that urokinase (uPA) is produced by the human prostate cancer cell line, PC-3, and could function as a growth factor for cells of the osteoblast phenotype. To examine the role of uPA in metastasis to the skeleton and to extraskeletal sites, we have developed a homologous model of uPA overexpression in a rat prostate cancer cell line. Full length cDNA encoding rat (r) uPA was isolated and subcloned as a 1.4-kilobase XbaI-BspHI fragment in the sense and antisense orientation into the Moloney murine leukemia retroviral vector pYN. The control (pYN) and experimental (pYN-ruPA, pYN-ruPA-AS) plasmids were transfected into Dunning R 3227, Mat LyLu rat prostate carcinoma cells. Experimental clones expressing at least 5-fold higher (pYN-ruPA) or 3-fold lower (pYN-ruPA-AS) than controls were selected, and control and experimental cells were inoculated into the left ventricles of inbred male Copenhagen rats. Animals were sacrificed at timed intervals to examine the evolution of metastatic lesions. Control animals developed metastases to the lumbar vertebrae resulting in spinal cord compression and hind limb paralysis at 20-21 days postinoculation. Animals inoculated with cells overexpressing uPA developed hind limb paralysis significantly earlier (by day 14-15 postinoculation). Additionally, more widespread skeletal (ribs, scapula, and femora) metastases were seen. Serum from experimental animals showed a progressive elevation in alkaline phosphatase levels, and histological examination of lumbar metastases revealed markedly increased osteoblastic activity over that observed in control animals. In contrast to this, animals inoculated with cells underexpressing uPA developed hind limb paralysis significantly later (days 25-29 postinoculation) and displayed decreased tumor metastasis. These studies support a role for the catalytic domain of uPA in enhancing both skeletal and nonskeletal prostate cancer invasiveness and are consistent with a role for the growth factor domain of uPA in mediating an osteoblastic skeletal response.
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PMID:Urokinase overproduction results in increased skeletal metastasis by prostate cancer cells in vivo. 816 83

Disulfide bonds are rarely found in cytoplasmic proteins. Mutations were selected for in Escherichia coli that allow disulfide bond formation in the cytoplasm. In the presence of these mutations, export-defective versions of alkaline phosphatase and mouse urokinase were able to fold into their enzymatically active conformations in the cytoplasm because their disulfide bonds were formed. The mutations were mapped to the gene for thioredoxin reductase and diminish or eliminate the activity of this enzyme. Thioredoxin itself was found to be unnecessary for this disulfide bond formation. Thioredoxin reductase, but not thioredoxin, is thus implicated in keeping cysteines reduced in cytoplasmic proteins.
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PMID:Mutations that allow disulfide bond formation in the cytoplasm of Escherichia coli. 825 21

The cellular receptor for urokinase-type plasminogen activator (uPAR) binds pro-urokinase (pro-uPA) and facilitates its conversion to enzymatically active urokinase (uPA). uPA in turn activates surface-bound plasminogen to plasmin, a process of presumed importance for a number of biologic processes including cell migration and resolution of thrombi. We have previously shown that uPAR is expressed on the plasma membrane of circulating neutrophils, and we now report that stimulation with phorbol myristate acetate (PMA), FMLP, or tumor necrosis factor-alpha results in a rapid increase in the expression of uPAR. This process is accompanied by an increased cell-associated plasminogen activation after preincubation of neutrophils with pro-uPA in vitro. By subcellular fractionation of unstimulated neutrophils, 50% of uPAR is recovered in fractions containing latent alkaline phosphatase, corresponding to an intracellular compartment of easily mobilizable secretory vesicles distinct from both primary and specific granules, whereas the remaining 50% of uPAR is associated with a compartment eluting close to the specific granules. In contrast, the ligand pro-uPA is primarily (approximately 80%) found in the specific granules, but small amounts of pro-uPA/uPA (approximately 20%) coelute with latent alkaline phosphatase. Stimulation of neutrophils with FMLP results in translocation of uPAR as well as of pro-uPA from the secretory vesicles, whereas stimulation with PMA is required to translocate material from specific granules. Flow cytometry of neutrophils saturated with exogenous diisopropyl fluorophosphate-uPA shows a large excess (approximately 90%) of unoccupied uPAR on resting as well as FMLP- and PMA-stimulated neutrophils, suggesting a possible role for exogenous pro-uPA in providing neutrophils with a potential for plasminogen activation. These processes may be important for neutrophil extravasation and migration through extracellular matrix and for the contribution of neutrophils to resolution of thrombi.
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PMID:The receptor for urokinase-type plasminogen activator and urokinase is translocated from two distinct intracellular compartments to the plasma membrane on stimulation of human neutrophils. 829 41

Phenotyping of cytokeratin (CK)18-positive cells in bone marrow is gaining increasing importance for future prognostic screening of carcinoma patients. Urokinase-type plasminogen activator receptor (uPA-R) is one example of a potential aggressive marker for those cells. However, a valid and reliable double staining method is needed. Using monoclonal antibodies against uPA-R and CK18, we modified an immunogold/alkaline phosphatase double staining protocol. UPA-R/CK18-positive tumor cell controls exhibited black uPA-R staining in 15-80% of cases and red CK18 staining in almost 100% of tumor cells. Isotype- and cross-matched controls were completely negative. Bone marrow from healthy donors was always CK18-negative. Reproducibility of CK18-positive cell detection was estimated in a series of specimens from 61 gastric cancer patients comparatively stained with the single alkaline phosphatase-anti-alkaline phosphatase (APAAP) and our double staining method (10(6) bone marrow cells/patient). In four cases, double staining could not reproduce CK18-positive cells. In 34 cases it revealed fewer or equal numbers, and in 23 cases more CK18-positive cells than the APAAP method. Overall quantitative analysis of detected cell numbers (838 in APAAP, range 1-280 in 10(6); double staining 808, range 0-253) demonstrated relative reproducibility of APAAP results by double staining of 97%. Correlation of results between both methods was significant (p < 0.001, linear regression). Sensitivity of double staining tested in logarithmic tumor cell dilutions was one CK18-positive cell in 300,000. Specific uPA-R staining was seen on CK18-positive cells in bone marrow from 29 of 61 patients, and also on single surrounding bone marrow cells. To test the specificity of this staining, bone marrow cytospins from 10 patients without tumor disease were stained for uPA-R with the APAAP method. uPA-R expression was confirmed in all 10 cases, with a mean of 6.5% uPA-R-positive cells in 1000 bone marrow cells (SEM 1.2%). These results suggest that our double staining protocol is a sensitive, reproducible, and specific method for routine uPA-R phenotyping of disseminated CK18-positive cells in bone marrow of carcinoma patients.
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PMID:Immunocytochemical phenotyping of disseminated tumor cells in bone marrow by uPA receptor and CK18: investigation of sensitivity and specificity of an immunogold/alkaline phosphatase double staining protocol. 901 10

Prostate cancer (PRCA) cells metastasize to bone with high frequency, inducing typical osteosclerotic lesions. To establish if local stimuli on the bone tissue may derive from metastatic colonies of prostatic origin, we evaluated the biologic activities secreted by human prostatic epithelium and effective on osteoblast-like cells in vitro. Supernatant from short-term tissue cultures of human prostatic tissue samples obtained from PRCA (35 cases) and benign prostatic hyperplasia (BPH, 12 cases) patients were applied to three models of cells with osteoblastic phenotype: two normal [rabbit osteoblasts (OB) and rat periosteal cells (PO)] and one transformed (human osteosarcoma cell line, MG63). Proliferative activity was monitored through enzymatic reduction of tetrazolium salts and expressed as relative mitogenic activities (RMA). Analysis of proliferation and alkaline phosphatase (ALP) activity, a marker of osteoblast function, demonstrates that conditioned media (CM) from PRCA cultures stimulate both growth and activity of osteoblast-like cells to a greater extent compared to CM from BPH. Furthermore, cell growth and activity of osteoblast-like cells are progressively increased by CM derived from patients with stage B (tumor confined within the prostate capsule), stage C (locally invasive tumor), and stage D (invasive tumor with distant metastasis) disease. One of the mechanisms potentially underlying the CM-stimulated effects on bone cells is associated with the urokinase (uPA) enzyme route, whose release progressively increases with the stage of disease. However, antibodies against uPA and p-aminobenzamidine (a low molecular weight urokinase inhibitor) treatment, which both inhibit the proliferative and differentiative effects induced by exogenous urokinase, partially slow down the effects of CM from PRCA tissue cultures, suggesting that additional factors are secreted by prostatic tumor cells in vitro. In conclusion, we show that the mitogenic and differentiative activities for osteoblasts produced by prostatic tumor cells in short-term tissue cultures are related to PRCA stage and may predict the behavior of skeletal metastases in single cases of tumor. In addition, the culture methods used may represent a valid model to study prostatic and bone cellular interactions, which may indicate new therapeutic approaches in metastatic prostate tumors.
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PMID:Human prostatic tumor cells in culture produce growth and differentiation factors active on osteoblasts: a new biological and clinical parameter for prostatic carcinoma. 943 95

1. This study aimed to determine the effect of luminal butyrate on proliferative kinetics, a differentiation marker (alkaline phosphatase), and a molecule that controls cell-substratum adhesion (urokinase) in histologically normal human rectal mucosa. 2. Ten subjects with a colonoscopically normal colon (seven had previous adenomas) were given either butyrate or saline enemas for 4 days in a double-blind cross-over manner. Rectal biopsies were taken before and after each course of enemas. Epithelial proliferative kinetics were measured immunohistochemically using antibodies to proliferating cell nuclear antigen. Urokinase and alkaline phosphatase activities were measured spectrophotometrically in biopsy homogenates. 3. Both saline and butyrate enemas were well tolerated and induced no histological change except for a significant increase in crypt length (P < 0.05). The number of proliferating cells per crypt also increased significantly after butyrate (P = 0.018). 4. Compared with saline enemas, butyrate did not affect kinetic indices nor alkaline phosphatase activities. However, mucosal urokinase activities were significantly lower in butyrate-treated patients (9.5 +/- 2.0 i.u./g) than in saline-treated patients (12.8 +/- 2.0 i.u./g; P = 0.045). 5. Delivering of extra butyrate to the distal colon in healthy subjects may stabilize cell-substratum adhesion in surface epithelium and therefore offer a potential mechanism by which elevating distal colonic luminal butyrate concentrations might be beneficial in patients with colitis or hyperproliferative large bowel epithelium.
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PMID:Effect of topical butyrate on rectal epithelial kinetics and mucosal enzyme activities. 985 67

Butyrate may have paradoxical effects on epithelial cells of similar origin. This study aimed to examine the hypothesis that one mechanism that dictates a cell's response to butyrate is its state of activation. First, the responses to 24 h exposure to butyrate (1-2 mM) of normal and neoplastic human colonic epithelial cells activated by their isolation and primary culture, and of colon cancer cell lines, LIM1215 and Caco-2, were examined. In primary cultures of normal and cancer cells, butyrate had no effect on alkaline phosphatase activities but significantly suppressed urokinase receptor expression by a mean +/- SEM of 30 +/- 12% and 36 +/- 9%, respectively. Interleukin-8 secretion was suppressed by 44 +/- 7% in normal cells (P < 0.05) but was unchanged in cancer cells. In contrast, the cell lines significantly increased alkaline phosphatase activities by >50%, urokinase receptor expression >2-fold and interleukin-8 secretion >3-fold in response to butyrate. Secondly, the effect of butyrate on Caco-2 cells was examined with or without prior exposure to a specific activating stimulus [tumour necrosis factor alpha (TNF alpha)]. Interleukin-8 secretion increased by 145 +/- 23% and 132 +/- 17% on 24 h exposure to 2 mM butyrate or 0.1 microM TNF alpha alone, respectively. However, in cells pre-treated with TNF alpha, butyrate significantly inhibited secretion by 34 +/- 7% below unstimulated levels. The response to butyrate of urokinase receptor, whose expression was not stimulated by TNF alpha, was unchanged. These effects were mimicked by trichostatin A, an inhibitor of histone deacetylase, suggesting that butyrate's paradoxical effects may have been operating by the same mechanism. In conclusion, some of the paradoxical effects of butyrate do not appear to represent inherent differences between normal and transformed cells. Rather, the response may be determined by the state of activation of the cells.
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PMID:Colonic epithelial cell activation and the paradoxical effects of butyrate. 1022 79

The effect of mannosamine, an inhibitor of glycosylphosphatidylinositol (GPI) anchor formation, on chondrocyte-mediated cartilage proteoglycan breakdown was investigated using cartilage explant cultures. Mannosamine inhibited interleukin 1alpha-, tumour necrosis factor alpha- and retinoic acid-stimulated proteoglycan release from bovine nasal and articular cartilage, and retinoic acid-stimulated proteoglycan release from human cartilage. Its effects on two GPI-anchored proteins [the urokinase receptor, which binds urokinase-type plasminogen activator (uPA) to cell surfaces, and alkaline phosphatase] were also studied using bovine chondrocytes. Enzyme histochemistry and zymography demonstrated cell-associated uPA-like serine proteinase activity and PA activity respectively which was not reduced by treatment of chondrocytes with mannosamine at concentrations effective at inhibiting cartilage proteoglycan breakdown. Similarly, the activity of cell-associated alkaline phosphatase was not reduced, except at mannosamine concentrations much higher than those used to inhibit proteoglycan breakdown. These results demonstrate that inhibition of proteoglycan breakdown by mannosamine is too potent to be explained by an effect on GPI-anchor formation.
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PMID:Evidence that the inhibition of cartilage proteoglycan breakdown by mannosamine is not mediated via inhibition of glycosylphosphatidylinositol anchor formation. 1064 7


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