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 effects of acupuncture on the disorders elicited by abnormalities of endocrine system were investigated in ovariectomized mice. Female mice (strain; C57BL/6) were ovariectomized (OVX) and acupuncture points, Shenshu ([Japanese pictograph see text] : BL23) on both side of the back were continuously stimulated by subcutaneous needles for 20 days. After completion of experimental sessions, animals were sacrificed and specific brain regions were assayed for catecholamine contents by high performance liquid chromatography with electro chemical detector (ECD-HPLC). The mitogenic activities of splenic lymphocytes were measured by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTS) assay and alkaline phosphatase (ALP) assay. Furthermore, the effects of needle stimulation on learning and memory ability were studied by the step-through type passive avoidance test. Norepinephrine and dopamine contents in the frontoparietal cerebral cortex, ventral hippocampus and olfactory bulb were decreased in the OVX group, and both MTS activity and ALP activity were decreased 20 days after ovariectomy. The mean latent period was also shortened in the passive avoidance test in the OVX group. However, applying needle stimulation increased norepinephrine and dopamine contents in the brain regions, and enhanced mitogenic activities of splenic lymphocytes. The stimulation also improved memory-related behavior. It was concluded from this study that after mice were stimulated by subcutaneous needle insertion, overall changes were observed in central nervous system (including retention of memory) and immune functions. The study suggests that acupuncture improves the memory loss and decrease of immune responses accompanying aging and/or menopause, and the that it may have an important role in medical care for the elderly.
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PMID:Acupuncture inhibits the decrease in brain catecholamine contents and the impairment of passive avoidance task in ovariectomized mice. 1047 21

Bone generation by autogenous cell transplantation in combination with a biodegradable scaffold is one of the most promising techniques being developed in craniofacial surgery. The objective of this combined in vitro and in vivo study was to evaluate the morphology and osteogenic differentiation of bone marrow derived mesenchymal progenitor cells and calvarial osteoblasts in a two-dimensional (2-D) and three-dimensional (3-D) culture environment (Part I of this study) and their potential in combination with a biodegradable scaffold to reconstruct critical-size calvarial defects in an autologous animal model [Part II of this study; see Schantz, J.T., et al. Tissue Eng. 2003;9(Suppl. 1):S-127-S-139; this issue]. New Zealand White rabbits were used to isolate osteoblasts from calvarial bone chips and bone marrow stromal cells from iliac crest bone marrow aspirates. Multilineage differentiation potential was evaluated in a 2-D culture setting. After amplification, the cells were seeded within a fibrin matrix into a 3-D polycaprolactone (PCL) scaffold system. The constructs were cultured for up to 3 weeks in vitro and assayed for cell attachment and proliferation using phase-contrast light, confocal laser, and scanning electron microscopy and the MTS cell metabolic assay. Osteogenic differentiation was analyzed by determining the expression of alkaline phosphatase (ALP) and osteocalcin. The bone marrow-derived progenitor cells demonstrated the potential to be induced to the osteogenic, adipogenic, and chondrogenic pathways. In a 3-D environment, cell-seeded PCL scaffolds evaluated by confocal laser microscopy revealed continuous cell proliferation and homogeneous cell distribution within the PCL scaffolds. On osteogenic induction mesenchymal progenitor cells (12 U/L) produce significantly higher (p < 0.05) ALP activity than do osteoblasts (2 U/L); however, no significant differences were found in osteocalcin expression. In conclusion, this study showed that the combination of a mechanically stable synthetic framework (PCL scaffolds) and a biomimetic hydrogel (fibrin glue) provides a potential matrix for bone tissue-engineering applications. Comparison of osteogenic differentiation between the two mesenchymal cell sources revealed a similar pattern.
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PMID:Repair of calvarial defects with customized tissue-engineered bone grafts I. Evaluation of osteogenesis in a three-dimensional culture system. 1451 75

It is known that calcium-phosphate (Ca-P) coatings are able not only to improve the bone bonding behaviour of polymeric materials, but at the same time play a positive role on enhancing cell adhesion and inducing the differentiation of osteoprogenitor cells. Recently an innovative biomimetic methodology, in which a sodium silicate gel was used as a nucleative agent, was proposed as an alternative to the currently available biomimetic coating methodologies. This methodology is especially adequate for coating biodegradable porous scaffolds. In the present work we evaluated the influence of the referred to treatment on the mechanical properties of 50/50 (wt%) blend of corn starch/ethylene-vinyl alcohol (SEVA-C) based scaffolds. These Ca-P coated scaffolds presented a compressive modulus of 224.6 +/- 20.6 and a compressive strength of 24.2 +/- 2.20. Cytotoxicity evaluation was performed according ISO/EN 10993 part 5 guidelines and showed that the biomimetic treatment did not have any deleterious effect on L929 cells and did not inhibit cell growth. Direct contact assays were done by using a cell line of human osteoblast like cells (SaOS-2). 3 x 10(5) cells were seeded per scaffold and allowed to grow for two weeks at 37( composite function)C in a humidified atmosphere containing 5% CO(2). Total protein quantification and scanning electron microscopy (SEM) observation showed that cells were able to grow in the pre-mineralized scaffolds. Furthermore cell viability assays (MTS test) also show that cells remain viable after two weeks in culture. Finally, protein expression studies showed that after two weeks osteopontin and collagen type I were being expressed by SaOS-2 cells seeded on the pre-mineralized scaffolds. Moreover, alkaline phosphatase (ALP) activity was higher in the supernatants collected from the pre-mineralized samples, when compared to the control samples (non Ca-P coated). This may indicate that a faster mineralization of the ECM produced on the pre-mineralized samples was occurring. Consequently, biomimetic pre-mineralization of starch based scaffolds can be a useful route for applying these materials on bone tissue engineering.
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PMID:Biological response to pre-mineralized starch based scaffolds for bone tissue engineering. 1574 19

Recent studies suggest that bone marrow stromal cells are a potential source of osteoblasts and chondrocytes and can be used to regenerate damaged tissues using a tissue-engineering (TE) approach. However, these strategies require the use of an appropriate scaffold architecture that can support the formation de novo of either bone and cartilage tissue, or both, as in the case of osteochondral defects. The later has been attracting a great deal of attention since it is considered a difficult goal to achieve. This work consisted on developing novel hydroxyapatite/chitosan (HA/CS) bilayered scaffold by combining a sintering and a freeze-drying technique, and aims to show the potential of such type of scaffolds for being used in TE of osteochondral defects. The developed HA/CS bilayered scaffolds were characterized by Fourier transform infra-red spectroscopy, X-ray diffraction analysis, micro-computed tomography, and scanning electron microscopy (SEM). Additionally, the mechanical properties of HA/CS bilayered scaffolds were assessed under compression. In vitro tests were also carried out, in order to study the water-uptake and weight loss profile of the HA/CS bilayered scaffolds. This was done by means of soaking the scaffolds into a phosphate buffered saline for 1 up to 30 days. The intrinsic cytotoxicity of the HA scaffolds and HA/CS bilayered scaffolds extract fluids was investigated by carrying out a cellular viability assay (MTS test) using Mouse fibroblastic-like cells. Results have shown that materials do not exert any cytotoxic effect. Complementarily, in vitro (phase I) cell culture studies were carried out to evaluate the capacity of HA and CS layers to separately, support the growth and differentiation of goat marrow stromal cells (GBMCs) into osteoblasts and chondrocytes, respectively. Cell adhesion and morphology were analysed by SEM while the cell viability and proliferation were assessed by MTS test and DNA quantification. The chondrogenic differentiation of GBMCs was evaluated measuring the glucosaminoglycans synthesis. Data showed that GBMCs were able to adhere, proliferate and osteogenic differentiation was evaluated by alkaline phosphatase activity and immunocytochemistry assays after 14 days in osteogenic medium and into chondrocytes after 21 days in culture with chondrogenic medium. The obtained results concerning the physicochemical and biological properties of the developed HA/CS bilayered scaffolds, show that these constructs exhibit great potential for their use in TE strategies leading to the formation of adequate tissue substitutes for the regeneration of osteochondral defects.
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PMID:Novel hydroxyapatite/chitosan bilayered scaffold for osteochondral tissue-engineering applications: Scaffold design and its performance when seeded with goat bone marrow stromal cells. 1694 10

Association of osteoprogenitor cells to calcium phosphate ceramics is currently under intense investigation, for its considered ability to induce bone formation and therefore to allow the successful repair of large bone defects. However, if the first experimental and clinical studies provided promising results, lack of new bone formation has been reported in a large number of animal experiments. In this context and since it has been reported that in some conditions, calcium phosphate ceramic microstructure induces ectopic bone formation, we investigated the effects of ceramic microporosity on the behavior of osteoprogenitor cells for the development of hybrid materials. Human bone marrow stromal cells (BMSCs) were seeded on beta-tricalcium phosphate (TCP) ceramics with 0, 25, or 45% microporosity and cell adhesion, viability, and osteoblastic differentiation have been studied for three weeks. Cell counts, measurement of MTS conversion, and LDH activity indicated that microporosity decreased the viability of BMSCs in a time and rate-dependent manner. In addition, microporosity inhibited osteoblastic differentiation as compared with nonmicroporous ceramics, as revealed by decreased alkaline phosphatase activity and osteocalcin secretion. Results of this in vitro study therefore highlight a negative role for beta-TCP microporosity in the behavior of human osteoprogenitor cells.
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PMID:beta-TCP microporosity decreases the viability and osteoblast differentiation of human bone marrow stromal cells. 1796 32

Calcium silicate (CaSiO(3)) is regarded as a potential bioactive material. However, its poor chemical stability and cytocompatibility limits its biological applications. The aim of this study is to incorporate Titanium (Ti) into CaSiO(3) to produce a ceramic with improved chemical stability and biological properties. Sphene (CaTiSiO(5)) ceramics were prepared by sintering sol-gel-derived CaTiSiO(5) powder compacts and their chemical stability was assessed by measuring the ions released and weight loss after soaking CaTiSiO(5) in simulating body fluid for 1, 3, 7, and 14 days. Results indicated that CaTiSiO(5) has a significantly improved chemical stability, compared with CaSiO(3). The ability of CaTiSiO(5) ceramics to support human bone-derived cells (HBDC) attachment, proliferation, and differentiation was assessed using scanning electron microscopy, MTS, and alkaline phosphatase activity assays, respectively. CaTiSiO(5) ceramics supported HBDC attachment and significantly enhanced their proliferation and differentiation, compared with CaSiO(3) ceramics. Taken together, this study demonstrates that the newly developed CaTiSiO(5) ceramics possess excellent chemical stability and bioactivity, suggesting their potential use in skeletal tissue regeneration and as coating onto currently available orthopedic/dental implants.
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PMID:Incorporation of titanium into calcium silicate improved their chemical stability and biological properties. 1796 34

For tissue engineering of bone, a carrier matrix and efficient cell seeding are desirable. This study analysed the effect of fibrin glue on bone marrow stromal cells (BMSC) adhesion, proliferation (MTS-Test), differentiation (alkaline phosphatase (AP), osteocalcin (OC), ELISA) and compared the results with cells seeded within culture media on a decellularized, xenogenic bone matrix. There was no significant difference regarding cell adhesion. Proliferation after one week was significantly increased without fibrin glue. AP was increased in both groups when compared with porous scaffolds without cells. OC secretion was increased under both seeding conditions. Microscopic investigation of the cells with fibrin-glue showed less cell-cell contacts. This study reveals that cell seeding with medium demonstrates similar adherence rates compared with fibrin glue. Fibrin glue significantly decreases cell proliferation. Cell differentiation with respect to ALP and OC is not affected. Further studies are required to assess the long term and in vivo effects of both methods with respect to BMSC viability and differentiation. Fibrin sealants seem not necessary to achieve cell adherence when using a porous bone matrix.
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PMID:Influence of fibrin glue on proliferation and differentiation of human bone marrow stromal cells seeded on a biologic 3-dimensional matrix. 1848 55

Evaluations of the osteoblast-like cell responses and osteoconductivity of a non-woven silica gel fabric were carried out to determine its potential for application as a scaffold material for use in bone tissue engineering. The silica gel solution was prepared by condensation following hydrolysis of tetraethyl orthosilicate under acidic conditions. The solution was spun under a 2kVcm(-1) electric field. The diameters of the as-spun silica gel fibers were in the range of approximately 0.7-6microm. The fabric was then heat-treated at 300 degrees C for 3h. The proliferation of pre-osteoblastic MC3T3-E1 cells evaluated by the MTS assay was lower than on the tissue culture plate (TCP) as many cells leaked through the large voids formed by the randomly placed long, narrow silica gel fibers, which further retarded cell growth. However, the expressions of extracellular signal-regulated kinase and transcriptional factor from the cells were higher when cultured on the non-woven silica gel fabrics than on TCP. The alkaline phosphatase (ALP) activity and differentiation marker expressions assessed by amplication via the reverse transcription-polymerase chain reaction, such as type I collagen, ALP and osteocalcin, were higher for cells cultured on non-woven silica gel fabrics than on TCP. The non-woven silica gel fabric showed good osteoconductivity in the calvarial defect New Zealand white rabbit model. To this end, the non-woven silica gel fabric has good potential as a scaffold material for bone tissue engineering due to its good biological properties.
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PMID:Evaluations of osteogenic and osteoconductive properties of a non-woven silica gel fabric made by the electrospinning method. 1867 90

The aim of this study is to investigate the effects of extremely low-frequency pulsed electromagnetic field (PEMF) on osteoblast-like cells. PEMF with a magnetic flux density of 1.55 mT at 48 Hz was employed to stimulate the MC3T3-E1 cell and the primary osteoblast cell derived from 2-day-old Sprague Dawley (SD) rat calvaria for different time. MTS method was applied to analyze cell proliferation and flow cytometry to detect cell cycle. The intracellular alkaline phosphatase (ALP) activity was measured by colorimetry. Our results demonstrated that PEMF of 1.55 mT at 48 Hz did not affect cell number of MC3T3-E1 cell, whereas the cell percentage of S and G(2)M phase decreased significantly. Although the cell number of the primary osteoblast cell did not alter by MTS assay after being exposed to PEMF for 24 h continuously, the cell percentage of S and G(2)M phase increased significantly. When culture time extended to 48 h, the cell number increased greatly and the cell percentage of S and G(2)M phase decreased significantly despite of the exposure type. After the primary osteoblast cell was exposed to PEMF for 24 h continuously, the ALP activity decreased significantly, whereas it increased significantly when being exposed to PEMF for 48 h continuously. From the results we concluded that PEMF of 1.55 mT at 48 Hz did not affect proliferation and differentiation of MC3T3-E1 cell, but it promoted proliferation, inhibited differentiation at proliferation stage, and promoted differentiation at differentiation stage of primary osteoblast cells.
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PMID:Effects of extremely low-frequency-pulsed electromagnetic field on different-derived osteoblast-like cells. 1882 Dec 5

Recent studies have associated mutations in lamin A/C, a component of the nuclear lamina, with premature aging and severe bone loss. In this study, we hypothesized that reduced expression of lamin A/C has a negative impact on osteoblastogenesis and bone formation in vitro. We inhibited lamin A/C using increasing doses of lamin A/C siRNA in normal human osteoblasts and differentiating mesenchymal stem cells (MSCs). Untreated cells and cells treated with vehicle but without the siRNA-oligo were used as control. The level of effectiveness of siRNA was determined by RT-PCR, Western blot, and immunofluorescence. Nuclear blebbing, a typical finding of lamin A/C inhibition, was quantified using propidium iodine staining, and its effect on cell survival was determined using MTS-formazan. Furthermore, alizarin red and alkaline phosphatase staining were correlated with osteocalcin secretion and levels of expression of osteocalcin, osterix, bone sialoprotein, and Runx2. Finally, the nuclear binding activity of Runx2, an essential transcription factor for osteoblast differentiation, was assessed using ELISA and EMSA. A successful inhibitory effect on the lamin A/C gene at doses of 400-800 nM oligo was obtained without affecting cell survival. Whereas osteoblast function was significantly affected by lamin A/C inhibition, siRNA-treated MSC showed a higher incidence of nuclear changes, lower osteoblast differentiation, and enhanced adipocyte differentiation. Finally, lamin A/C knockdown reduced Runx2 nuclear binding activity without affecting Runx2 expression. In summary, our results indicate that lamin A/C is a new factor needed for osteoblast differentiation that plays an important role in the cellular mechanisms of age-related bone loss.
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PMID:Effect of lamin A/C knockdown on osteoblast differentiation and function. 1884 34


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