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)

The objective of this study was to investigate the in vitro bioactivity of strontium-containing hydroxyapatite (Sr-HA), and its effect on cellular attachment, proliferation, and differentiation. The effect of Sr-HA has been compared with that of hydroxyapatite (HA), which is widely used in orthopedics and dentistry. Sr-HA ceramic containing 10 mol % was prepared. The bioactivity of Sr-HA was evaluated in vitro by immersion in simulated body fluid (SBF). After immersion in SBF, Sr-HA exhibited greater ability to induce apatite precipitation on its surface than did HA. The possible effects on cell behavior of Sr-HA were examined by culturing osteoprecursor cells (OPC1) on materials surfaces. Cell shape and cell-material interactions were analyzed by scanning electron microscope (SEM) and the MTT assay was used to determine cell proliferation on samples. When compared with HA, Sr-HA promoted better OPC1 cell attachment and proliferation, and showed no deleterious effects on extracellular matrix formation and mineralization. Confocal scanning microscopy was used to assess the expression of specific osteoblast proteins: alkaline phosphatase (ALP) and osteopontin (OPN). The results obtained indicate that the presence of Sr stimulates OPC1 cell differentiation, and enhances ALP and OPN expression.
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PMID:Osteoprecursor cell response to strontium-containing hydroxyapatite ceramics. 1688 20

Statin, a HMG-CoA reductase inhibitor, was shown to increase BMP-2 gene expression for bone formation, by blocking the mevalonate pathway in cholesterol production. We investigated the effect of naringin, a flavonoid available commonly in citrus fruits, which was also a HMG-CoA reductase inhibitor, in UMR 106 osteoblastic cell line in vitro. The control group consisted of cells cultured without any intervention for different time intervals (24 h, 48 h, and 72 h), whereas the experimental (naringin) group consisted of cells cultured with naringin of different concentrations (0.001 micromol/L, 0.01 micromol/L, and 0.1 micromol/L) for the same time intervals of the control. Colorimetric Tetrazolium (MTT) assay, total protein content assay, and alkaline phosphatase activity were used to measure the cellular activities. Results for the naringin group showed an increase in MTT assay compared with the control and the effect was dose dependent. At high concentration (0.1 micromol), the increases ranged from 60% to 80%. In the total protein content assay, naringin also showed an increase compared with control and the effect was also dose dependent. At high concentration (0.1 micromol), the increases ranged from 9% to 20%. In the alkaline phosphatase activity assay, naringin at high concentration (0.1 micromol) significantly increased the activity up to 20%. In conclusion, naringin significantly increased bone cell activities in vitro. This is the first study specifically attempted to investigate the effect of naringin on bone cell activities. Besides statin, this provided another example of mevalonate pathway blockage in the cholesterol production pathway by HMG-CoA reductase inhibition will increase the bone cell activities.
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PMID:Effect of naringin on bone cells. 1694 74

Pancreatic cancer is one of the tumors with the highest mortality, poorly responding to available chemotherapeutic agents. The objective of this study was to study the anticancer effects of all-trans retinoid acid, a functional form of vitamin A, on pancreatic cancer cells. Human pancreatic cancer MiaPaCa-2 cells were treated with 1, 5, 10, 20, 30, 40 and 50 microM ATRA for 1, 2, 3, 4, 5 or 6 d, respectively. Cell growth was determined by MTT viability assay. The cell cycle distribution and the alkaline phosphatase (ALP) activity were analyzed by flow cytometry and chemical analyzer, respectively. The results show that ATRA significantly inhibited the growth of MiaPaCa-2 cells at 40 and 50 microM. ATRA arrested pancreatic cancer cells at G0/G1 phase. The sub-G1 peak and DNA fragmentation were observed. There were time and dose dependent increases in alkaline phosphatase activity (ALP), an indicator of cell differentiation, upon treatment with ATRA when compared to controls. In conclusion, ATRA has an inhibitory effect on the cell growth of MiaPaCa-2, and its tumor suppressive effect is by means of cell cycle arrest and apoptosis induction.
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PMID:The effects of all-trans-retinoic acid on cell cycle and alkaline phosphatase activity in pancreatic cancer cells. 1701 84

We have proposed the use of the fluorimetric method with 4-methylumbelliferyl phosphate (4-MUP) specific substrate for the alkaline phosphatase determination in the neutrophil adhesion assay. We provide evidence that the endogenous neutrophil alkaline phosphatase (NAP) activity evaluation is reliable to quantify neutrophil adhesion at a wide range of cell numbers (10(4)-10(6)). The results obtained by fluorimetric NAP activity test correlate to the results of adherence evaluated using the MTT reduction assay. The fluorimetric NAP activity test may be applied for resting as well as activated neutrophils without the risk of the activators interferences into the test. The alkaline phosphatase survey with the use of 4-MUP substrate is recommended herein as a sensitive, repeatable, simple, and reliable method of the neutrophil adherence determination in vitro.
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PMID:Application of intracellular alkaline phosphatase activity measurement in detection of neutrophil adherence in vitro. 1704 86

Calcium phosphates (CaPs) have been investigated as substrates to promote bone formation both in vitro and in vivo. The aim of this study was to examine the proliferation and differentiation of rat bone marrow stromal cells (BMSCs) cultured on three-dimensional (3D) octacalcium phosphate (OCP) crystal assemblies. The cytotoxicity of OCP crystal assemblies was evaluated by measuring the lactate dehydrogenase (LDH) release from BMSCs during 10h of incubation with OCP crystal assemblies. The proliferation of BMSCs on OCP crystal assemblies in medium with or without osteogenic supplements was also investigated using the MTT assay with tissue culture treated plastic (TP) as the control. The tissues formed by BMSCs cultured on OCP crystal assemblies for 24 days were examined following staining with haematoxylin and eosin (H&E), alkaline phosphatase (ALP) and Van Gieson's techniques. The influence of OCP crystal assemblies on mRNA expression of alpha chain of collagen type I (Coll-Ia), ALP and osteocalcin (OC), osteonectin (ON), osteopontin (OP), lumican, Cbfa1, EST317 and EST350 by the BMSCs were also investigated using semi-quantitative RT-PCR. Although OCP crystals were relatively cytotoxic compared with TP, proliferation of BMSCs occurred when seeded onto OCP crystal assemblies. BMSCs cultured on OCP demonstrated similar proliferation rates as found on the control and no significant difference (P<0.05) in the number of cells cultured in medium supplemented with or without osteogenic additives on TP and OCP. The deposition of collagen and ALP were detected in tissue synthesised by BMSCs cultured on OCP crystals assemblies. OCP crystal assemblies down-regulated basal bone ECM proteins, including Coll-Ia, ON and lumican, in the first week of culture, whilst up-regulation of the same genes was observed after 24 days of culture. The observed down-regulation of Cbfa1 on OCP substrates was consistent with the negative effect of OCP crystal assemblies on the genes encoding bone ECM proteins. The up-regulation of OC mRNA expression by OCP crystal assemblies could be related to the requirement for synthesis of more OC proteins to control the concentration of calcium ions in culture medium.
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PMID:Influence of calcium phosphate crystal assemblies on the proliferation and osteogenic gene expression of rat bone marrow stromal cells. 1716 82

Hepatitis C-associated osteosclerosis (HCAO) is a rare syndrome characterized by severe, acquired, generalized osteosclerosis and hyperostosis in adults who are infected with the hepatitis C virus. However, the detail of the pathogenesis of HCAO is still unknown. We examined the effects of serum of the HCAO patient on the proliferation, alkaline phosphatase (ALP) activity and transforming growth factor (TGF)-beta-Smad signaling in mouse osteoblastic cells. The patient was compatible with HCAO, characterized by high bone mass, bone thickening and bone pain with normal lamelar bone. The serum from the HCAO patient increased the levels of TGF-beta and Smad3 expression in osteoblastic MC3T3-E1 cells, compared with the control subject. Moreover, the serum from the HCAO patient significantly augmented TGF-beta-induced transcriptional activity with luciferase assay using 3TP-Lux with a Smad3-specific responsive element. In addition, the serum from the HCAO patient significantly stimulated the MTT intensity, the level of proliferating cell nuclear antigen expression, a proliferation marker, and ALP activity in MC3T3-E1 cells, compared with that from the control subject. In conclusion, the present study indicated that the serum from the HCAO patient stimulated TGF-beta-Smad signaling, as well as the proliferation and ALP activity in osteoblastic cells. Some soluble factors other than parathyroid hormone might be related to the pathogenesis of HCAO.
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PMID:Serum soluble factors induce the proliferation, alkaline phosphatase activity and transforming growth factor-beta signal in osteoblastic cells in the patient with hepatitis C-associated osteosclerosis. 1717 44

The aim of this study was to investigate the effects of collagen on the microstructure and biocompatibility of chitosan-collagen composite sponges fabricated by a freezing and drying technique. The study was categorized into four groups: Group I: collagen; Group II: chitosan; Group III: 1:1 (by wt) chitosan-collagen and Group IV: 1:2 (by wt) chitosan-collagen sponges. A mouse osteoblast cell line, MC3T3-E1, was cultivated on the sponges in a mineralized culture medium for 21 days. Microstructure of scaffolds and growth of cells on the sponges were examined using scanning electron and confocal laser scanning electron microscopes. Pore size was analysed from scanning electron microscope images using Image-Pro Plus image analysis software. Cell viability (MTT assay), alkaline phosphatase activity and levels of osteocalcin and calcium were monitored every 3 days and on days 15 and 21, respectively. It was found that the sponges were porous with average pore sizes of 80-100 microm. A combination of chitosan and collagen matrixes created a well defined porous microstructure and biocompatible scaffolds. Chitosan-collagen composite sponges promoted growth and differentiation of osteoblasts into the mature stage. To optimize application of the composite sponges in bone regeneration, the fabrication process must be improved to increase the pore size of the scaffolds.
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PMID:Growth and differentiation of mouse osteoblasts on chitosan-collagen sponges. 1722 12

The local application of antibiotics in bone cement achieves high local effective antibiotic concentrations. Cefuroxime is widely used for antibiotic prophylaxis in orthopedic surgery, and several reports highlighted a beneficial outcome if cefuroxime-impregnated bone cement was used, but there is a lack of information of direct cefuroxime effects on human bone cells. We, therefore, cultured osteoblasts, previously derived from human trabecular bone specimens and used as a cell-pool further on, with different concentrations of cefuroxime (0-1000 microg/mL) for 24, 48, or 72 h. For reversibility testing, osteoblasts were cultivated for 24 h with cefuroxime followed by 48 h without antibiotics. Cell proliferation (MTT), cytotoxicity (lactate dehydrogenase (LDH)-activity), cell metabolism (alkaline phosphatase (ALP)-activity), and extracellular matrix calcification (Alizarin staining) were assessed after antibiotic treatment. Cefuroxime concentrations of 25-100 microg/mL had little or no effect on cellular proliferation. Proliferation was significantly stimulated at 250 and 1000 microg/mL at each time. LDH-activity significantly increased at the highest concentration of 1000 microg/mL at 72 h. ALP-activity first increased at lower concentrations and then significantly decreased at 1000 microg/mL at 48 and 72 h. Similar to ALP-activity, calcification increased at lower concentrations and was not detectable at 1000 microg/mL. All revealed effects at 24 h were at least partially reversible. In the present study, we demonstrated that cefuroxime at lower concentrations had no inhibiting effects on human osteoblasts. In contrast, higher concentrations significantly altered osteoblastic function. When administered locally in total joint arthroplasty, for example, in antibiotic-impregnated bone cement, cefuroxime might critically impair osteoblastic function and periprosthetic bone metabolism.
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PMID:Effects of cefuroxime on human osteoblasts in vitro. 1729 50

Activated platelets release a multifaceted blend of growth factors that has stimulatory effects on mesenchymal cells, both in vitro and in vivo, which imply beneficial effects on wound repair and tissue regeneration. Previous studies on fibroblast cultures have revealed that more potent growth factors, with respect to cell proliferation, are released in acidic preparations of lysed platelet concentrates in comparison with neutral and alkaline preparations. The current study was intended to investigate the influence of pH on lysed platelet concentrates with respect to release of growth factors, cell proliferation and alkaline phosphatase (ALP) activity in human osteoblast-like cells (hFOB 1.19). Cell proliferation was assessed with the MTT kit, ALP activity by conventional enzymatic reaction kinetics and growth factors platelet-derived growth factor (PDGF) and transforming growth factor-beta (TGF-beta) by enzyme-linked immunosorbent assays. Osteoblast-like cells were stimulated with lysed platelet concentrates preincubated at pH 4.4, 5.4, 7.4, and 7.6. A 3-13-fold increase of cell proliferation was found in comparison with controls and the most evident increase was observed with platelets activated at pH 5.4. The highest ALP activity was observed in preparations at pH 7.6. Platelets incubated in an acidic environment (pH 5.4) induced a higher proliferation compared with preincubation at neutral or alkaline pH and the level of PDGF was also found to be higher in acidic preincubations. The level of TGF-beta was, in contrast, lowest at pH 4.4. We suggest, based on these experimental findings, that acidic milieu influence platelets to release growth factors more potent to stimulate osteoblast proliferation than neutral and alkaline platelet preparations. Lysed platelet concentrates prepared at an alkaline pH might release additional components with stimulating effects resulting in other features than cell proliferation. This is the first report, to our knowledge, about a pH dependent stimulatory effect of lysed platelet concentrates on human osteoblast-like cell proliferation. Lysed platelet concentrates, preincubated in acidic or alkaline buffers, may benefit fracture healing, implant fixation and might also be advantageous in the treatment of wounds with platelet constituents; however, this has to be investigated in extended experimental and clinical settings.
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PMID:Variation of pH in lysed platelet concentrates influence proliferation and alkaline phosphatase activity in human osteoblast-like cells. 1736 59

with chitosan in situ using a chemical method and a porous structure obtained was then lyophilized. Preosteoblast MC 3T3-E1 the scaffolds was examined after staining it with Wright's stain. Their proliferation was assessed using MTZ assay. After being Abstract Nanohydroxyapatite/chitosan composite scaffolds were fabricated and the proliferation and differentiation of preosteoblast MC 3T3-E1 on them were examined for the assessment of their biocompatibility. Nanohydroxyapatite was combined with chitosan in situ using a chemical method and a porous structure obtained was then lyophilized. Preosteoblast MC 333-E1 cells were inoculated into the porous composite scaffolds and chitosan scaffolds, respectively. The morphology of cells cultured on the scaffolds was examined after staining it with Wright's stain. Their proliferation was assessed using MTT assay. After being cultured in conditioned medium for 30 days, the cells' alkaline phosphatase activities on the scaffolds were studied in situ to compare their differentiation levelabout. Moreover, the alkaline phosphatase activities were assessed with a kit. The expression level of characteristic osteogenic gene was evaluated using Reverse Transcription-Polymerase Chain Reaction (RT-PCR). The results indicated that MC 3T3-E1 cells grown on the composite scaffolds showed a higher proliferation rate and spread better than that on chitosan scaffolds. The alkaline phosphatase stain results showed that the alkaline phosphatase activity of cells on composite scaffolds was significantly higher than that on the chitosan scaffolds. In addition, the quantitative examination of alkaline phosphatase activity indicated that the cells cultured on the composite scaffolds expressed an activity level about 8 times higher than that on chitosan scaffolds. Simultaneously, the osteogenic gene osteopontin (OPN) of cells cultured on composite scaffolds showed a higher expression level than that on chitosan scaffolds. Another osteogenic gene osteocalcin (OC) was expressed in cells cultured on composite scaffolds, whereas it was not detected in cells on chitosan scaffolds. The addition of nanohydroxyapatite in the scaffolds improved not only the proliferation but also the differentiation of preosteoblast cultured on them. The composite scaffolds showed good biocompatibility and bioactivity. These scaffolds would be promising in bone tissue engineering.
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PMID:[Proliferation and differentiation of MC 3T3-E1 cells cultured on nanohydroxyapatite/chitosan composite scaffolds]. 1746 Aug 99


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