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)

Oligonucleotide 15-mers containing one or two anthraquinonylmethyl groups at specified sugar residues have been prepared on an automated DNA/RNA synthesizer by using 5'-O-dimethoxytrityl 2'-O-(2-anthraquinonylmethyl)uridine 3'-O-(2-cyanoethyl)-N, N-diisopropylphosphoramidite. The purification of the modified oligonucleotides was done with denaturing polyacrylamide gel electrophoresis. The base compositions and the presence of anthraquinone group(s) in the oligonucleotides were verified with enzymatic digestion (snake venom phosphodiesterase and alkaline phosphatase) analysis and UV-vis spectral measurements. The UV melting behaviors indicate that all the oligonucleotides with anthraquinone group(s) can bind to both their complementary DNA and RNA in a manner similar to that of the unmodified oligonucleotide. All the oligonucleotides possessing anthraquinone group(s) have higher affinity for both DNA and RNA segments when compared with the unmodified oligonucleotide. The oligomer containing two anthraquinone substituents at sites separated by four nucleotides instead of six exhibits the highest affinity for both the complementary DNA and RNA. The stabilizing effect can be translated into a free energy cost of 7.1 kcal/mol for the DNA hybrid and 3.6 kcal/mol for RNA. It has been shown through mismatch/Tm studies that modification of the oligonucleotide by anthraquinone groups does not alter the sequence specificity in binding to a RNA segment.
...
PMID:Incorporation of two anthraquinonylmethyl groups into the 2'-O-positions of oligonucleotides: increased affinity and sequence specificity of anthraquinone-modified oligonucleotides in hybrid formation with DNA and RNA. 895 Apr 90

Although it is well accepted that implant success is dependent on various surface properties, little is known about the effect of surface roughness on cell metabolism or differentiation, or whether the effects vary with the maturational state of the cells interacting with the implant. In the current study, we examined the effect of titanium (Ti) surface roughness on chondrocyte proliferation, differentiation, and matrix synthesis using cells derived from known stages of endochondral development. Chondrocytes derived from the resting zone (RCs) and growth zone (GCs) of rat costochondral cartilage were cultured on Ti disks that were prepared as follows: HF-HNO3-treated and washed (PT); PT-treated and electropolished (EP); fine sand-blasted, HCl-H2SO4-etched, and washed (FA); coarse sand-blasted, HCl-H2SO4-etched, and washed (CA); or Ti plasma-sprayed (TPS). Based on surface analysis, the Ti surfaces were ranked from smoothest to roughest: EP, PT, FA, CA, and TPS. Cell proliferation was assessed by cell number and [3H]-thymidine incorporation, and RNA synthesis was assessed by [3H]-uridine incorporation. Differentiation was determined by alkaline phosphatase specific activity (AL-Pase). Matrix production was measured by [3H]-proline incorporation into collagenase-digestible (CDP) and noncollagenase-digestible (NCP) protein and by [35S]-sulfate incorporation into proteoglycan. GCs required two trypsinizations for complete removal from the culture disks; the number of cells released by the first trypsinization was generally decreased with increasing surface roughness while that released by the second trypsinization was increased. In RC cultures, cell number was similarly decreased on the rougher surfaces; only minimal numbers of RCs were released by a second trypsinization. [3H]-thymidine incorporation by RCs decreased with increasing surface roughness while that by GCs was increased. [3H]-Uridine incorporation by both GCs and RCs was greater on rough surfaces. Conversely, ALPase in the cell layer and isolated cells of both cell types was significantly decreased. GC CDP and NCP production was significantly decreased on rough surfaces while CDP production by RC cells was significantly decreased on smooth surfaces. [35S]-sulfate incorporation by RCs and GCs was decreased on all surfaces compared to tissue culture plastic. The results of this study indicate that surface roughness affects chondrocyte proliferation, differentiation, and matrix synthesis, and that this regulation is cell maturation dependent.
...
PMID:Effect of titanium surface roughness on chondrocyte proliferation, matrix production, and differentiation depends on the state of cell maturation. 901 78

This study examined the effect of recombinant human bone morphogenetic protein-2 on several parameters of growth, differentiation, and matrix synthesis and on the endogenous production of mRNA of bone morphogenetic proteins 2 and 4 by growth plate chondrocytes in culture. Chondrocytes from resting and growth zones were obtained from rat costochondral cartilage and cultured for 24 or 48 hours in medium containing 0.05-100 ng/ml recombinant human bone morphogenetic protein-2 and 10% fetal bovine serum. Incorporation of [3H]thymidine, cell number, alkaline phosphatase specific activity, incorporation of [3H]proline into collagenase-digestible protein and noncollagenase-digestible protein, and incorporation of [35S]sulfate were assayed as indicators of cell proliferation, differentiation, and extracellular matrix synthesis. mRNA levels for bone morphogenetic proteins 2 and 4 were determined by Northern blot analysis. Recombinant human bone morphogenetic protein-2 increased the incorporation of [3H]thymidine by quiescent resting-zone and growth-zone cells in a similar manner, whereas it had a differential effect on nonquiescent cultures. At 24 and 48 hours, 12.5-100 ng/ml recombinant human bone morphogenetic protein-2 caused a dose-dependent increase in cell number and DNA synthesis in resting-zone chondrocytes. No effect was seen in growth-zone cells. Recombinant human bone morphogenetic protein-2 stimulated alkaline phosphatase specific activity in resting-zone chondrocytes in a bimodal manner, causing significant increases between 0.2 and 0.8 ng/ml and again between 25 and 100 ng/ml. In contrast, alkaline phosphatase specific activity in growth-zone chondrocytes was significantly increased only between 12.5 and 100 ng/ml. Recombinant human bone morphogenetic protein-2 increased the production of both collagenase-digestible protein and noncollagenase-digestible protein by resting-zone and growth-zone cells, but incorporation of [35S]sulfate was unaffected. Administration of recombinant human bone morphogenetic protein-2 also increased incorporation of [3H]uridine in both resting-zone and growth-zone chondrocytes; these cells produced mRNA for bone morphogenetic proteins 2 and 4. Bone morphogenetic protein-2 mRNA levels in both resting-zone and growth-zone chondrocytes increased in the presence of recombinant human bone morphogenetic protein-2; however, bone morphogenetic protein-4 mRNA levels in growth-zone cells decreased under its influence, and those in resting-zone cells were upregulated only with a dose of 10 ng/ml. This indicates that recombinant human bone morphogenetic protein-2 regulates chondrocyte proliferation, differentiation, and matrix production, and the effects are dependent on the stage of cell maturation. Resting-zone chondrocytes were more sensitive, suggesting that they are targeted by bone morphogenetic protein-2 and that this growth factor may have autocrine effects on these cells.
...
PMID:Recombinant bone morphogenetic protein (BMP)-2 regulates costochondral growth plate chondrocytes and induces expression of BMP-2 and BMP-4 in a cell maturation-dependent manner. 924 83

Both 17 beta-estradiol (17 beta) and the vitamin D metabolites, 1,25-(OH)2D3(1,25) and 24,25-(OH)2D3(24,25), regulate endochondral bone formation in vivo and in vitro. The effects of 17 beta are sex-specific and cell maturation-dependent. Similarly, the effects of 1,25 and 24,25 are cell maturation-dependent, with 1,25 affecting growth zone chondrocytes (GC) and 24,25 affecting resting zone chondrocytes (RC). This study examined whether the response of chondrocytes to 17 beta is altered after pretreatment with 1,25 or 24,25. Cells were isolated from the costochondral cartilage of male or female rats. Confluent, fourth-passage GC and RC cultures were pretreated with 1,25 or 24,25, respectively, for 24 or 48 h followed by treatment with 17 beta for an additional 24 h. At harvest, cell proliferation ([3H]-thymidine incorporation), differentiation (alkaline phosphatase specific activity [ALPase]), general metabolism ([3H]-uridine incorporation), and proteoglycan production ([35S]-sulfate incorporation) were determined. 1,25 enhanced the inhibitory effect of 17 beta on [3H]-thymidine incorporation by female GC cells; in contrast, no effect was observed in GC cells obtained from male rats. When male RC cells were treated with 17 beta, [3H]-thymidine incorporation was inhibited; however, when these cells were pretreated with 24,25 for 48 h, 17 beta stimulated [3H]-thymidine incorporation 24,25 had no effect on 17 beta-dependent [3H]-thymidine incorporation by female RC cells. 17 beta stimulated ALPase in female GC cells, but had no effect on male GC cells. 1,25 pretreatment of female GC cells inhibited the stimulatory effect of 17 beta on ALPase, but had no effect on ALPase in male GC cultures. 17 beta had no effect on male RC cell ALPase and stimulated ALPase in female RC cells. This was not affected by pretreatment with 24,25. Pretreatment with 1,25 increased the basal level of sulfate incorporation only in female GC. No effect was found in RC cells. These results indicate that pretreatment of rat costochondral chondrocytes with vitamin D metabolites modulate the effect of 17 beta. Although the effect of vitamin D metabolites alone on these chondrocytes is maturation-dependent and not sex-specific, the influence of preincubation with vitamin D metabolites on the effect of 17 beta is hormone-specific, sex-specific, and maturation-dependent.
...
PMID:The effects of 17 beta-estradiol on chondrocyte differentiation are modulated by vitamin D3 metabolites. 954 47

Benzylacyclouridine (BAU, IND 039655) is a potent and specific inhibitor of uridine phosphorylase (UrdPase; EC 2.4.2.3). This enzyme plays a major role in regulating uridine homeostasis and also catalyzes the conversion of fluoropyrimidine nucleosides to their respective bases. Inhibition of UrdPase enzyme activity 18-24 h after 5-fluorouracil (5-FU) administration increased plasma levels of uridine and enhanced the therapeutic index of 5-FU by rescuing normal tissues. Moreover, in vitro preclinical studies have also shown that inhibiting UrdPase enzyme activity by BAU prior to administration of 5-FU increased cytotoxicity in a number of human cancer cell lines. A series of preclinical studies was performed in dogs and pigs to evaluate the pharmacological and pharmacodynamic properties of BAU. These data showed a sustained elevation in plasma uridine concentration in both animal models. The rapid degradation of a tracer dose of uridine into uracil was virtually arrested by BAU administered both p.o. or i.v. The t1/2 of BAU was 1.8-3.6 h in dogs, with bioavailability levels of 85% (30 mg/kg) and 42.5% (120 mg/kg). In pigs, the half-life varied from 1.6 to 2.3 h, with a bioavailability of 40% at 120 mg/kg. The drug was distributed into most tissues with a tissue: plasma ratio of approximately 0.7. On the basis of these preclinical studies, we performed a Phase I clinical trial of BAU in patients with advanced cancer. Patients received 200, 400, 800, and 1600 mg/m2 BAU as a single oral dose. Toxicities included grade 2 anemia, grade 1 fever, grade 1 fatigue, grade 1 constipation, and grade 1 elevation in alkaline phosphatase; none of these toxicities were observed to be dose dependent. The maximum tolerated dose and dose-limiting toxicity were not reached at the doses given. BAU plasma concentrations and area under the curve correlated linearly with the oral dose level. The pharmacokinetics of BAU were consistent with a first-order clearance, with average peak concentrations ranging from 19 microM (200 mg/m2) to 99 microM (1600 mg/m2) and tbeta1/2 ranging from 3.0 to 3.9 h at the four dose levels. Compared with baseline plasma uridine, treatment of patients with 200, 400, 800, and 1600 mg/m2 BAU increased peak uridine concentrations by 120, 150, 250, and 175%, respectively. On the basis of this clinical study, the suggested Phase II starting dose of BAU in combination with 5-FU is 800 mg/m2. Studies combining BAU with 5-FU and incorporating appropriate molecular and biochemical end points to assess the effects of this drug combination on tumor and/or surrogate tumor tissue are under way.
...
PMID:Phase I clinical and pharmacological studies of benzylacyclouridine, a uridine phosphorylase inhibitor. 960 74

The effects of vitamin C and aloe vera gel extract supplementation on induced hepatocarcinogenesis in male Sprague-Dawley rats (120-150 g) by diethylnitrosamine (DEN) and 2-acetylaminofluorene (AAF) was investigated. The severity of the carcinogenesis process was determined by measuring gamma-glutamyl transpeptidase (GGT) and the placental form of glutathione S-transferase (GSTP) histochemically in situ and in plasma and liver fractions. In addition, plasma alkaline phosphatase (ALP) and liver microsomal uridine diphosphate glucuronyl transferase (UDPGT) activity were also determined. Administration of DEN/AAF caused an increase in the surface area and number of enzyme-positive foci (both GGT and GSTP) compared with control. Supplementation of vitamin C or aloe vera gel extract to the cancer-induced rats suppressed this increase significantly (P < 0.05; P < 0.001). Increases in liver UDPGT, GGT, and GSTP activities were also observed with cancer induction that were again suppressed with either vitamin C or aloe vera gel supplementation. Plasma GGT in the DEN/AAF rats were determined monthly for the duration of the experiment and found to be reduced as early as 1 mo with aloe vera gel supplementation and 2 mo with vitamin C supplementation. In conclusion, vitamin C and aloe vera gel extract supplementation were found to be able to reduce the severity of chemical hepatocarcinogenesis.
...
PMID:Vitamin C and aloe vera supplementation protects from chemical hepatocarcinogenesis in the rat. 983 27

A bacterial alkaline phosphatase (BAP, the phoA gene product) is primarily responsible for the hydrolysis of the substrates 5-bromo-4-chloro-3-indolylphosphate-p-toluidine (XP) and p-nitrophenyl phosphate (pNPP). Using these substrates and an E. coli phoA mutant, we have cloned Enterobacter aerogenes genes conferring an XP(+) phenotype. Two types of clones were identified based on phenotypic tests and DNA sequences. One of them is a E. aerogenes phoA gene (XP(+), pNPP(+)) as expected; surprisingly the other one was found to be a ushA gene (XP(+), pNPP(-)), which encodes an UDP (uridine 5'-diphosphate)-sugar hydrolase. The E. aerogenes ushA gene shares high sequence identity with ushA of E. coli and the mutationally silent ushA0 gene of Salmonella typhimurium at both the nucleotide (over 79%) and amino acid (over 93%) levels. Expression of the E. aerogenes ushA gene in E. coli produced high level of UDP-sugar hydrolase, as confirmed by TLC (thin layer chromatography) analysis together with a presence of a strong band due to a XP hydrolysis on a polyacrylamide gel.
...
PMID:Cloning and characterization of the UDP-sugar hydrolase gene (ushA) of Enterobacter aerogenes IFO 12010. 1070 87

Carbocyclic 3-deazaadenosine (C-c3Ado) is a potent inhibitor of Ebola virus in mice by infrequent dosing, even though its half life in plasma is only 23-28 min. This prompted studies to determine whether C-c3Ado undergoes intracellular metabolism to derivatives that may promote in vivo activity. In cells, radiolabelled compound readily underwent metabolism to monophosphate, diphosphate and triphosphate (C-c3ATP) forms, with C-c3ATP being the major metabolite detected. A non-polar metabolite was also detected both inside and outside treated cells. The retention time of C-c3ATP was similar but not identical to ATP on a strong anion exchange high performance liquid chromatography (HPLC) column or on a DEAE-Sephadex open column. C-c3ATP and ATP were susceptible to degradation to their respective nucleosides by bovine alkaline phosphatase. Intracellular formation of C-c3ATP reached a plateau by about 4 h after treatment of monkey (Vero 76) and mouse (Balb/3T3 clone A31) cells with 10 or 100 microM extracellular compound. Phosphorylation was linearly dose responsive at 1, 3 and 10 microM. However, the extent of phosphorylation decreased with increasingly higher concentrations (30, 100 and 300 microM). When compound was removed from the medium, the nucleoside cleared the cells within 1 min, whereas C-c3ATP had a half life of decay of 2-3 h in five cell lines. Phosphorylation of C-c3Ado to C-c3ATP was not inhibited by cotreatment of cells (at a 20:1 ratio) with adenosine, guanosine, inosine, xanthosine, cytidine or uridine. There was no evidence of incorporation of C-c3Ado (10 microM) into macromolecules of cells over 72 h, whereas adenosine was readily incorporated. C-c3ATP may represent a form of C-c3Ado that might contribute to extending its intracellular half life or otherwise exhibit antiviral activity and/or toxicity.
...
PMID:Intracellular phosphorylation of carbocyclic 3-deazaadenosine, an anti-Ebola virus agent. 1177 34

To test the hypothesis that human concentrative and equilibrative nucleoside transporters (hCNT1 and hENT1) are present on the apical and basolateral membrane, respectively, we constructed a Madin-Darby canine kidney (MDCK) cell line that simultaneously and stably expresses recombinant hCNT1 and hENT1 gene products tagged with CFP and YFP fluorescent proteins, respectively. Using a confocal microscope, both hCNT1-CFP and hENT1-YFP were found to be distributed uniformly on the plasma membrane of undifferentiated MDCK cells. Upon differentiation of the MDCK cells on Transwell filter inserts, hCNT1-CFP was visualized exclusively on the apical membrane, whereas hENT1-YFP appeared predominantly on the basolateral membrane. As differentiation proceeded, there was an increase in alkaline phosphatase activity, and activity of hENT1 in the apical compartment decreased while hCNT1 activity remained constant. These results suggest that, on differentiation, hENT1 is sorted to the basolateral membrane. This was confirmed when the hCNT1-mediated uptake of [(3)H]uridine from the apical compartment of the differentiated cells was found to be approximately 20-fold higher and that for hENT1 was approximately 4-fold lower than the corresponding uptake from the basal compartment. As observed in vivo, the net transport of [(3)H]adenosine was from the apical to the basal compartment, whereas that for (14)C-deoxyadenosine was from the basal to the apical compartment. In summary, we have shown for the first time that hCNT1 and hENT1 are expressed in polarized MDCK cells on the apical and basolateral membrane, respectively, allowing vectorial transport in both directions depending on the relative activity (ratio of maximal transporter activity to affinity) of each transporter for their substrates.
...
PMID:Simultaneous expression of hCNT1-CFP and hENT1-YFP in Madin-Darby canine kidney cells. Localization and vectorial transport studies. 1209 33

Elongation of the primer 32pdA(pdA)8pA proceeds by the reaction of the 5'-phosphorimidazolides of adenosine and uridine in the presence of montmorillonite clay. Daily addition of the activated nucleotides for up to 14 days results in the formation of 40-50 mers using the 5'-phosphorimidazolide of adenosine (ImpA) and 25-30 mers using the 5'-phosphorimidazolide of uridine (ImpU). The limitation on the lengths of the chains formed is not due to the inhibitors formed since the same chain lengths were formed using 2-3 times the amount of montmorillonite catalyst. The shorter oligomers formed by the addition of U monomers is not due to its greater rate of decomposition since it was found that both the A and the U adducts decompose at about the same rates. Alkaline phosphatase hydrolysis studies revealed that some of the oligomers are capped at the 5'-end to form, with ImpA, Ap32pdA(pdA)8pA(pA)n. The extent of capping depends on the reaction time and the purine or pyrimidine base in the activated mononucleotide. Hydrolysis with ribonuclease T2 followed by alkaline phosphatase determined the sites of the 3', 5'- and 2', 5'-phosphodiester bonding to the primer. The potential significance of the mineral catalyzed formation of 50 mer oligonucleotides to the origin of life based on RNA (the RNA world scenario) is discussed.
...
PMID:Montmorillonite catalysis of 30-50 mer oligonucleotides: laboratory demonstration of potential steps in the origin of the RNA world. 1245 36


<< Previous 1 2 3 4 5 6 7 Next >>

---