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

---

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

Phytoestrogens are plant chemicals that are structurally analogous to estrogen and are known to affect estrogenic activity. Biochanin A, a naturally occurring isoflavone, has been identified and detected in various diets and plant species. We examined the effects of biochanin A on the differentiation of osteoblastic MC3T3-E1 cells and the production of local factors in osteoblasts. Biochanin A (1-50 microM) caused a significant elevation of cell growth, alkaline phosphatase (ALP) activity, collagen content, and osteocalcin secretion in osteoblastic MC3T3-E1 cells (p<0.05). The effect of biochanin A (10 microM) in increasing ALP activity and collagen content was completely prevented by the presence of 10(-6) M cycloheximide and 10(-6) M tamoxifen, suggesting that biochanin A's effect results from a newly synthesized protein component and might be partly involved in estrogen action. We then examined the effect of biochanin A on the H2O2-induced production of inflammatory mediators in osteoblasts. Biochanin A (1-10 microM) decreased the 0.2 mM H2O2-induced production of TNF-alpha, IL-6 and NO in osteoblasts. These results suggest that biochanin A may be useful as potential phytoestrogens, which play important physiological roles in the prevention of postmenopausal osteoporosis.
...
PMID:Biochanin A stimulates osteoblastic differentiation and inhibits hydrogen peroxide-induced production of inflammatory mediators in MC3T3-E1 cells. 1620 52

Persistent inflammation and associated excessive oxidative stress have been crucially implicated in quartz-induced pulmonary diseases, including fibrosis and cancer. We have investigated the significance of the particle surface reactivity of respirable quartz dust in relation to the in vivo generation of reactive oxygen and nitrogen species (ROS/RNS) and the associated induction of oxidative stress responses in the lung. Therefore, rats were intratracheally instilled with 2 mg quartz (DQ12) or quartz whose surface was modified by either polyvinylpyridine-N-oxide (PVNO) or aluminium lactate (AL). Seven days after instillation, the bronchoalveolar lavage fluid (BALF) was analysed for markers of inflammation (total/differential cell counts), levels of pulmonary oxidants (H2O2, nitrite), antioxidant status (trolox equivalent antioxidant capacity), as well as for markers of lung tissue damage, e.g. total protein, lactate dehydrogenase and alkaline phosphatase. Lung homogenates as well as sections were investigated regarding the induction of the oxidative DNA-lesion/oxidative stress marker 8-hydroxy-2'-deoxyguanosine (8-OHdG) using HPLC/ECD analysis and immunohistochemistry, respectively. Homogenates and sections were also investigated for the expression of the bifunctional apurinic/apyrimidinic endonuclease/redox factor-1 (APE/Ref-1) by Western blotting and immunohistochemistry. Significantly increased levels of H2O2 and nitrite were observed in rats treated with non-coated quartz, when compared to rats that were treated with either saline or the surface-modified quartz preparations. In the BALF, there was a strong correlation between the number of macrophages and ROS, as well as total cells and RNS. Although enhanced oxidant generation in non-coated DQ12-treated rats was paralleled with an increased total antioxidant capacity in the BALF, these animals also showed significantly enhanced lung tissue damage. Remarkably however, elevated ROS levels were not associated with an increase in 8-OHdG, whereas the lung tissue expression of APE/Ref-1 protein was clearly up-regulated. The present data provide further in vivo evidence for the crucial role of particle surface properties in quartz dust-induced ROS/RNS generation by recruited inflammatory phagocytes. Our results also demonstrate that quartz dust can fail to show steady-state enhanced oxidative DNA damage in the respiratory tract, in conditions were it elicits a marked and persistent inflammation with associated generation of ROS/RNS, and indicate that this may relate to compensatory induction of APE/Ref-1 mediated base excision repair.
...
PMID:The crucial role of particle surface reactivity in respirable quartz-induced reactive oxygen/nitrogen species formation and APE/Ref-1 induction in rat lung. 1626 28

Cell-titanium interactions are crucial to the clinical success of bone and dental implants. The physico-chemical characteristics of the substrates surface influence osteoblast proliferation, differentiation, and activity as well. The osteoblast behavior was analyzed on three different titanium surfaces: ground with an abrasive 600 grit SiC paper, blasted with alumina particles (65 microm diameter) and alumina blasted followed by a double chemical etch (4% HF+4% HF/8% H2O2). Scanning electron microscopy (SEM) and profilometry showed distinct microtopographies. Ground samples showed parallel-groove orientation. The Al2O3-blasted surface presented the roughest microtopography with aluminum-rich particles incrusted in the titanium surface. Osteoblasts cells from femora of Balb/c mice were seeded onto the substrates tested. Cell morphology and initial attachment were evaluated by SEM. Osteoblasts adhered to and spread on all samples tested. However, on rough surfaces, osteoblasts did not spread completely and acquired a polygonal morphology. Besides, the cell proliferation rate was diminished at the beginning of incubation on rough surfaces. Our results suggest a delay, rather than an impairment, in osteoblast viability and alkaline phosphatase activity when cells are cultured on rough surfaces, inducing a distinct osteoblast phenotype, rather than blocking its activity. At least in the culture conditions used in this work, alumina particles did not affect osteoblast behavior.
...
PMID:Effect of three distinct treatments of titanium surface on osteoblast attachment, proliferation, and differentiation. 1630 73

Hydrogen peroxide (H(2)O(2)), an oxidizing agent, has been widely used as a disinfectant. Recently, because of its reactive properties, H(2)O(2) has also been used as a tooth bleaching agent in dental care. This is a cause for concern because of adverse biological effects on the soft and hard tissues of the oral environment. To investigate the influence of H(2)O(2) on odontoblasts, the cells producing dentin in the pulp, we assessed cellular viability, generation of reactive oxygen species (ROS), alkaline phosphatase (ALP) activity, and nodule formation of an odontoblastic cell line (MDPC-23) after treatment with H(2)O(2), and compared those with the effects on preosteoblastic MC3T3-E1 cells. Cytotoxic effects of H(2)O(2) began to appear at 0.3 mmol/L in both MDPC-23 and MC3T3-E1 cells. At that concentration, the accumulation of intracellular ROS was confirmed by a fluorescent probe, DCFH-DA. Although more ROS were detected in MDPC-23, the increasing pattern and rate are similar between the two cells. When the cells were treated with H(2)O(2) at concentrations below 0.3 mmol/L, MDPC-23 displayed a significant increase in ALP activity and mineralized bone matrix, while MC3T3-E1 cells showed adverse effects of H(2)O(2). It is known that ROS are generally harmful by-products of aerobic life and represent the primary cause of aging and numerous diseases. These data, however, suggest that ROS can induce in vitro cell differentiation, and that they play a more complex role in cell physiology than simply causing oxidative damage.
...
PMID:Effects of hydrogen peroxide (H2O2) on alkaline phosphatase activity and matrix mineralization of odontoblast and osteoblast cell lines. 1646 18

It has been amply documented that L-ascorbic acid added to the medium of a cell culture increases oxidative damage, and this effect of L-ascorbic acid has been ascribed to the generation of reactive oxygen intermediates in the medium during its auto-oxidation. We have here questioned whether such an effect is exerted inside the cell as well, and if so, what its mechanism is. To assess thiol oxidation in the cell, we manipulated CHO cells so that they could express bacterial alkaline phosphatase in the cytoplasm. Alkaline phosphatase activity, which requires the formation of intramolecular disulfide bridges, was shown to appear when the cells were exposed to H2O2. This H2O2-induced activity increased more than 1.5 fold when L-ascorbic acid had been loaded in the cells by incubation with L-ascorbic acid-2-O-phosphate. Similar enhancing effects were also observed by assessing oxidation of glutathione, formation of protein carbonyls, and generation of reactive oxygen intermediates. Interestingly, the effects by the L-ascorbic acid-2-O-phosphate treatment were totally suppressed by addition of the membrane-permeable chelator deferoxamine to the medium, indicating the involvement of iron ions. Because the apoprotein of conalbumin, which binds iron ions with a high affinity, had no effect and because the same deferoxamine effect was observed with the cells incubated in balanced salt solution with no metal salts added, it was concluded that L-ascorbic acid acts as a pro-oxidant within the cell suffering oxidative stress, and that this effect is elicited through increased redox-cycling of iron in combination with L-ascorbic acid.
...
PMID:Enhanced oxidative stress by L-ascorbic acid within cells challenged by hydrogen peroxide. 1652 98

Different industrial processes exist to purify allogenic bone, providing safe and cleaned blocks for bone allografting. However, they often make use of chemical reagents that can be aggressive for the bone matrix. Bone samples were processed with several soaking techniques used in industry: NaHCO3, H2O2, NaOH and H2O2+NaOH combined; the consequences on the bone matrix and cytocompoatibility were evaluated on femoral heads from osteoarthritic patients. Alterations of matrix were searched by histochemistry, atomic force microscopy (AFM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Cytocompatibility was evaluated by coculturing human osteoblast-like cells (SaOS-2) on bone slices. Collagen fibers were dramatically altered at the surface of bone treated with H2O2, NaOH (and their association), but not with NaHCO3. A marked reduction in the number of hydroxyapatite crystals was observed on the trabecular surfaces by TEM and morphological changes were evidenced in SEM and AFM. Argyrophilic proteins of the bone matrix were removed by H2O2 and NaOH (and their association), but not by NaHCO3. As a consequence, attachment, spreading, proliferation and alkaline phosphatase activity of SaOS-2 were reduced by H2O2 and NaOH treatments. Strong oxidizing reagents altered matrix integrity by modifying collagenous and non-collagenous proteins. Whether these changes have clinical consequences on the bone bonding and osseointegration in human necessitate further investigations.
...
PMID:The influence of processes for the purification of human bone allografts on the matrix surface and cytocompatibility. 1661 1

In free-living Amoeba proteus (strain B), 3 phosphatase were found after disc-electrophoresis of 10 microg of protein in PAGE and using 1-naphthyl phosphate as a substrate a pH 9.0. These phosphatases differed in their electrophoretic mobilities - "slow" (1-3 bands), "middle" (one band) and "fast" (one band). In addition to 1-naphthyl phosphate, "slow" phosphatases were able to hydrolyse 2-naphthyl phosphate and p-nitrophenyl phosphate. They were slightly activated by Mg2+, completely inhibited by 3 chelators (EDTA, EGTA and 1,10-phenanthroline), L-cysteine, sodium dodecyl sulfate and Fe2+, Zn2+ and Mn2+ (50 mM), considerably inactivated by orthovanadate, molybdate, phosphatase inhibitor cocktail 1, p-nitrophenyl phosphate, Na2HPO4, DL-dithiothreitol and urea and partly inhibited by H2O2, DL-phenylalanine, 2-mercaptoethanol, phosphatase inhibitor cocktail 2 and Ca2+. Imidazole, L-(+)-tartrate, okadaic acid, NaF and sulfhydryl reagents -p-(hydroxy-mercuri)benzoate and N-ethylmaleimide - had no influence on the activity of "slow" phosphatases. "Middle" and "fast" phosphatases, in contrast to "slow" ones, were not inactivated by 3 chelators. The "middle" phosphatase differed from the "fast" one by smaller resistance to urea, Ca2+, Mn2+, phosphates and H2O2 and greater resistance to dithiothreitol and L-(+)-tartrate. In addition, the "fast" phosphatase was inhibited by L-cysteine but the "middle" one was activated by it. Of 5 tested ions (Mg2+, Cu2+, Mn2+, Ca2+ and Zn2+), only Zn2+ reactivated "slow" phosphatases after their inactivation by EDTA treatment. The reactivation of apoenzyme was only partial (about 35 %). Thus, among phosphatases found in amoebae at pH 9.0, only "slow" ones are Zn-metalloenzymes and may be considered as alkaline phosphatases (EC 3.1.3.1). It still remains uncertain, to which particular phosphatase class "middle" and "fast" phosphatases (pH 9.0) may belong.
...
PMID:[Alkaline phosphatase in Amoeba proteus]. 1670 60

4-Hydroxynonenal (HNE), a lipid peroxidation end product, is produced abundantly in osteoarthritic (OA) articular tissues, but its role in bone metabolism is ill-defined. In this study, we tested the hypothesis that alterations in OA osteoblast metabolism are attributed, in part, to increased levels of HNE. Our data showed that HNE/protein adduct levels were higher in OA osteoblasts compared to normal and when OA osteoblasts were treated with H2O2. Investigating osteoblast markers, we found that HNE increased osteocalcin and type I collagen synthesis but inhibited alkaline phosphatase activity. We next examined the effects of HNE on the signaling pathways controlling cyclooxygenase-2 (COX-2) and interleukin-6 (IL-6) expression in view of their putative role in OA pathophysiology. HNE dose-dependently decreased basal and tumour necrosis factor-alpha (TNF-alpha)-induced IL-6 expression while inducing COX-2 expression and prostaglandin E2 (PGE2) release. In a similar pattern, HNE induces changes in osteoblast markers as well as PGE2 and IL-6 release in normal osteoblasts. Upon examination of signaling pathways involved in PGE2 and IL-6 production, we found that HNE-induced PGE2 release was abrogated by SB202190, a p38 mitogen-activated protein kinase (MAPK) inhibitor. Overexpression of p38 MAPK enhanced HNE-induced PGE2 release. In this connection, HNE markedly increased the phosphorylation of p38 MAPK, JNK2, and transcription factors (CREB-1, ATF-2) with a concomitant increase in the DNA-binding activity of CRE/ATF. Transfection experiments with a human COX-2 promoter construct revealed that the CRE element (-58/-53 bp) was essential for HNE-induced COX-2 promoter activity. However, HNE inhibited the phosphorylation of IkappaBalpha and subsequently the DNA-binding activity of nuclear factor-kappaB. Overexpression of IKKalpha increased TNF-alpha-induced IL-6 production. This induction was inhibited when TNF-alpha was combined with HNE. These findings suggest that HNE may exert multiple effects on human OA osteoblasts by selective activation of signal transduction pathways and alteration of osteoblastic phenotype expression and pro-inflammatory mediator production.
...
PMID:Alterations of metabolic activity in human osteoarthritic osteoblasts by lipid peroxidation end product 4-hydroxynonenal. 1704 56

The development of a simultaneous multianalyte immunoassay for the detection of progesterone and human chorionic gonadotropin (hCG) in serum is described. In this simultaneous multianalyte assay, two different enzymes, viz. horse radish peroxidase (HRP) and alkaline phosphatase (ALP), were used as markers. To the simultaneous immobilized progesterone and hCG antibody microwells, 50 microL of different concentrations of combined standards or serum samples was added in duplicate and then 100 microL of combined conjugate reagent, composed of 17-alpha-OH-P-ALP and hCG-biotin was added to all the wells and incubated for 1h at 37 degrees C. After incubation, the contents of the wells were decanted and washed thoroughly with running tap water. After washing, 100 microL alkaline phosphatase substrate along with streptavidin-horseradish peroxidase was added to all the wells and incubated for 0.5 h at 37 degrees C. After incubation, the developed color was measured at 405 nm. The absorbency at this stage provides the result for the progesterone assay. The contents of the wells were decanted and washed. In the next step, 100 microL of tetramethylbenzidene/H2O2 reagent was added to all the wells. After 15 min of incubation, 100 microL of 0.5 M H2SO4 was added to all the wells and the color was read at 450 nm. The absorbency at this stage provides the result for the hCG assay. Sensitivity of the progesterone and hCG assays were 0.118 ng/ml and 0.124 IU/ml respectively. Intra- and inter assay percentage coefficients of variation ranged from 1.8 to 7.1 and 9.1 to 11.5 for progesterone and from 2.1 to 10.4 and 7.2 to 11.3 for hCG. There was good correlation between the discrete and the simultaneous assays. For progesterone assay, R2 was 0.99 and for hCG R2 was also 0.99. The developed dual assay for progesterone and hCG may be useful for the diagnosis of abnormal pregnancies such as miscarriages and ectopic pregnancies.
...
PMID:Development of dual-enzyme-based simultaneous immunoassay for measurement of progesterone and human chorionic gonadotropin. 1754 Mar 32

Genetic hemochromatosis is an iron overload disorder, and osteopenic and osteoporotic. Femoral neck bone mineral density (BMD) appears to fall with rising hepatic iron concentrations. A critical role for iron in mediating tissue injury is played via hydroxyl radical formation in nephrotoxicity. We investigated the effects of a colloidal iron overload on renal function, organ siderosis, and femoral bone in male rats. Iron overload reduced body growth, and increased the weights of the liver and spleen. Marked deposition of iron was noted in liver and kidney. Activities of lactate dehydrogenase and alkaline phosphatase were decreased, and the concentrations of blood urea nitrogen and creatinine were increased with the reduction in plasma calcium and inorganic phosphorus levels, i.e. functions of the liver and kidney might be affected by reactive oxygen species such as the superoxide radical, H2O2, and the hydroxyl radical produced by overloaded iron. Damage to the proximal tubular epithelial cells of the kidney and a loss of connectivity of cancellous bone in the epiphysis and of trabecular bone in the metaphysis of the distal femur were observed in iron-overloaded rats with a reduction of femoral bone mineral density, i.e. reabsorption of calcium from the proximal tubular epithelial cells of the kidney might be affected and urinary discharge of calcium might be elevated. It was suggested that iron overload gave rise to osteoporosis combined with renal dysfunction and liver iron overload syndrome.
...
PMID:Effects of colloidal iron overload on renal and hepatic siderosis and the femur in male rats. 1828 63


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---