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)

We have established a cell line (KU-SN) from a peripheral neuroectodermal tumor originating in the left scapula of a 4-year-old girl. The original tumor was immunoreactive with antibodies for neurofilament proteins, neuron-specific enolase, vimentin, S100 protein, and beta 2-microglobulin. Dense core granules, 50-150 nm in diameter, were identified by electron microscopy. The cell line was established from tumor cells in metastatic lung fluid. KU-SN cells were immunoreactive with the antibodies for neurofilament proteins, vimentin, neuron-specific enolase, S100 protein, glial fibrillary acidic protein, cytokeratin, and carcinoembryonic antigen. Besides these neuronal features, KU-SN cells express type 2 collagen and insulin-like growth factor 1 receptor. The addition of insulin-like growth factor 1 (100 ng/ml) increased the growth rate of KU-SN cells 2.1-fold over control. Some cells were positive for Alcian blue and alkaline phosphatase staining. Cytogenetic analysis of KU-SN cells disclosed a reciprocal chromosomal translocation [t(11,22)]. Northern blot analysis of KU-SN cells demonstrated amplified expression of the c-myc gene but not the N-myc gene. When tumor cells were transplanted into nude mice, cartilage was formed. The cartilage was immunoreactive with the antibody for HLA-ABC, indicating that it was derived from the tumor cells, not from mouse tissue. Chondrocytic differentiation was not observed in xenografts of Ewing's sarcoma cell lines SK-ES or RD-ES or the peripheral neuroectodermal tumor cell line SK-N-MC. These results indicate that KU-SN cells represent primitive neural crest cells having the potential for chondrocytic differentiation.
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PMID:Chondrocytic differentiation of peripheral neuroectodermal tumor cell line in nude mouse xenograft. 137 22

Experimental studies in vitro indicate that insulin-like growth factor 1 (IGF-1) could be of importance for normal bone growth and remodelling, but the clinical relevance of these observations is unknown. In 12 consecutive young to middle-aged male patients (mean age (+/- SD) 46 +/- 8 years, range 30-57 years) with symptomatic idiopathic osteoporosis, the plasma concentrations of IGF-1 were significantly lower than in healthy subjects (0.51 +/- 0.25 vs. 0.73 +/- 0.23 U ml-1; P less than 0.01). The bone mineral densities in the spine, the femoral neck, and the forearm were significantly different between patients and control subjects. There were positive correlations between the plasma IGF-1 concentrations and the bone densities of the spine and the forearm. Three of the patients received a 5-d course of human recombinant growth hormone (GH). During this short period significant increases in plasma IGF-1 levels and in biochemical indices of bone turnover (serum bone-specific alkaline phosphatase, urinary calcium excretion) were recorded. These observations indicate that circulating IGF-1 could have an important role in maintaining bone mass, and suggest that impairment of IGF-1 production is involved in the pathogenesis of osteoporosis.
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PMID:Low plasma levels of insulin-like growth factor 1 (IGF-1) in male patients with idiopathic osteoporosis. 164 Jan 93

Transferrin (TF) has a growth promoting activity in cell culture. The aim of this work was to study possible relationships between serum TF, alkaline phosphatase activity (ALP), plasma insulin-like growth factor 1 (IGF-1) levels and rate of height increase in boys. 149 boys aged 13-15 yrs were studied. TF levels were measured using turbidimetric method. The serum levels of ALP could be used as a biochemical marker for bone formation. Significant correlation was found between serum TF levels and ALP levels (r = 0.31, P less than 0.0005). The TF levels are higher in iron-deficiency anemia. The hemoglobin (Hb) and serum ferritin were measured in all boys. Thirty-one of 149 boys had no iron-deficiency anemia (Hb 14.0 g/dl and serum ferritin 23 ng/ml). The rate of growth in height was estimated over a 5 month period. In these boys, the rate of growth in height was significantly correlated with serum TF levels (r = 0.37; P less than 0.05). A significant correlation was found between serum TF levels and plasma IGF-1 levels (r = 0.45; P less than 0.05). These data indicate that serum TF levels may be a marker of skeletal growth in normal boys.
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PMID:Serum transferrin as a marker of bone growth in boys: correlation with serum alkaline phosphatase activity, plasma insulin-like growth factor 1 and rate of growth in height. 187 82

The presence of many types of polypeptide growth factors in the mineralized extracellular matrix of bone is now well established. These factors are generally referred to as bone-derived growth factors (BDGFs), and are similar, or possibly identical, to the following species; platelet-derived growth factor (PDGF); acidic and basic forms of fibroblast growth factor (aFGF, bFGF); transforming growth factor beta (TGF-beta); and insulin-like growth factor 1 (IGF-1). Several osteoinductive factors, such as bone morphogenetic protein (BMP) and osteogenin, a skeletal growth factor (SGF), and osteoblast-derived BDGFs, have also been identified. Complete description of the biological functions of these BDGFs which are relevant to bone will ultimately require specific bioassays involving specific cell types in vitro, as well as in vivo animal implant models. Studies with primary rat osteoblast-like cells exposed either to mixed BDGFs, pure TGF-beta, or heparin-purified PDGF, aFGF, or bFGF from bovine bone have shown a general dose-dependent mitogenic effect. Phenotypic changes which accompany the BDGF-induced wave of proliferation include: decreased osteocalcin secretion and a reduction in 1,25-(OH)2 vitamin D3-stimulated osteocalcin synthesis; reduced alkaline phosphatase specific activity; decreased cyclic AMP responsiveness to parathyroid hormone (PTH); and increased collagen synthesis. Bone exhibits the most complex spectrum of growth factor activities of any tissue yet described. In bovine bone powder free of blood and cartilage contamination, the volume concentration of mitogens is up to 20 times greater than that in serum. Bone cells and other indigenous cell types must be considered as possible sources of the BDGFs, in addition to sequestration from blood. Mechanisms for the unmasking or release of BDGFs from the mineralized matrix that result in local action on osteoblasts, endothelial cells, and other target cells are undoubtedly important for the development and maintenance of bone tissue.
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PMID:Polypeptide growth factors in bone matrix. 306 10

Short-term exposure to smokeless tobacco extracts (STE) reportedly inhibits osteoblast metabolism. The objective of this study was to determine the effects of serial dilutions of a water-soluble extract of smokeless tobacco on osteoblast proliferation and their potential to form and mineralize bone nodules. STE significantly stimulated cell proliferation when diluted 10(2)-10(4) times; 10(3) and 10(4) dilutions produced the greatest effect. 10(2)-10(4) STE dilutions significantly increased alkaline phosphatase activity at day 7 but 10(6) STE dilutions significantly decreased it. 10(3) and 10(4) dilutions significantly increased bone nodule formation, but inhibited their mineralization. In contrast, 10(5) and 10(6) dilutions significantly decreased bone nodule formation, but increased their mineralization. Stimulation of in vitro bone nodule formation by STE was similar to that produced by 10(-7) M insulin-like growth factor 1 (IGF-1) in vivo. Heat and acid treatment of STE significantly reduced its beneficial effect on cell proliferation, suggesting that a peptide within STE may be responsible for enhancement of osteogenic cell proliferation. Thus, STE may contain a peptide capable of significantly stimulating osteoblast proliferation, differentiation and metabolism, similar to the effects of IGF-1. This peptide could have potential therapeutic benefits.
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PMID:The effects of smokeless tobacco extract on bone nodule formation and mineralization by chick osteoblasts in vitro. 757 33

Recent studies have suggested that cementoblasts may be derived from osteoblast progenitor cells, although the cementoblast phenotype has not been extensively characterized. This immunocytochemical study was carried out to investigate the expression by rat cementoblasts of a number of proteins which are characteristic of the osteoblast phenotype. Paraffin sections from developing rat tooth germs and from fully formed adult rat teeth with surrounding tissues, were incubated with antibodies to type I & III collagen, osteocalcin, transforming growth factor beta (TGE beta), and insulin-like growth factor 1 (IGF1). Frozen sections and unfixed resin-embedded sections were stained for alkaline phosphatase activity. Cementum and bone matrix were strongly positive for type I collagen, although there was only weak staining for type III collagen. Cementum was also positive for osteocalcin, which was particularly strong in the matrix of acellular cementum. Most osteoblasts and cementoblasts of the cellular cementum showed intense staining for TGF beta and IGF1, although some cementocytes and osteocytes were negatively stained. The osteoblast- specific anti-E11 mAb reacted strongly with cementoblasts and newly formed cementocytes in the cellular cementum. Cells associated with acellular cementum did not express TGF beta, IGF1 or stain positively with anti-E11 antibody at any time during root development. Cementoblasts were weakly or negatively stained for alkaline phosphatase in contrast to the osteoblasts examined, which may reflect the low level of synthetic activity in cementoblasts. These results demonstrate that osteoblasts and cementoblasts of cellular cementum share many phenotypic characteristics, and also suggest that there may be phenotypic differences between cementoblasts associated with cellular and acellular cementum.
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PMID:Immunocytochemical investigation of the rat cementoblast phenotype. 825 58

Twenty-one prepubertal, short Japanese children (11 boys) without endocrine abnormalities were identified as having mild-to-moderate zinc deficiency by zinc kinetics studies (zinc body clearance > or = 20 ml/kg per hour). Only one child had a serum zinc level < 65 micrograms/dl (cutoff level). A total of 10 children (5 boys) received 5 mg/kg per day of zinc sulfate for 6 months; 11 untreated children (6 boys) served as control subjects. During treatment, calorie intake (p < 0.01), growth velocity (p < 0.01), serum zinc, calcium, and phosphorus concentrations, alkaline phosphatase activity (p < 0.001), percentage of tubular reabsorption of phosphorus (p < 0.05), ratio of maximal tubular reabsorption rate for phosphorus to the glomerular filtration rate (p < 0.05), serum osteocalcin level (p < 0.01), and plasma insulin-like growth factor 1 (p < 0.05) were significantly increased, but urinary excretion of growth hormone was unchanged in the zinc-supplemented group. All these values were unchanged in the untreated children. We conclude that zinc supplementation is effective for inducing growth in short children with zinc deficiency, and that body zinc clearance tests facilitate detection of marginal zinc deficiency.
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PMID:Mild to moderate zinc deficiency in short children: effect of zinc supplementation on linear growth velocity. 811 Feb 94

In order to determine whether growth hormone (GH) exerts a direct effect on osteoblasts, in vitro and in vivo immunocytological studies were carried out on newborn rat calvaria and a clonal osteoblast-like cell line (MC3T3-E1) isolated from newborn mouse calvaria. After exposure to human growth hormone (hGH) or 1,25 dihydroxyvitamin D3 (1,25(OH)2D3), a significant increase in alkaline phosphatase activity was observed in MC3T3-E1 cells. Simultaneous exposure of MC3T3-E1 cells to hGH and 10 nM 1,25(OH)2D3 showed a synergistic effect of the two hormones on this activity. The optimal dose of hGH was 0.1 nM. An immunocytological procedure was performed on ultrathin frozen sections from 7-day-old rat calvaria and MC3T3-E1 cells cultured with hGH. GH-like immunoreactivity was observed in both cases. In calvaria, endogenous GH-like immunoreactivity was localized at the same ultrastructural level (plasma membrane, cytoplasmic and nuclear matrices) as exogenous GH-like immunoreactivity in MC3T3-E1 cells. Following the initial step of binding to the plasma membrane, GH may be internalized in the cytoplasmic matrix and nucleus. In situ hybridization revealed the presence of mRNA coding for GH receptor in calvaria cells. The density of these receptors seemed to be lower in osteoblasts than in hepatocytes. In MC3T3-E1 cells, hGH induced a dose-dependent secretion of insulin-like growth factor 1. In conclusion, these results indicate that GH may act directly on osteoblasts.
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PMID:Evidence for a direct effect of growth hormone on osteoblasts. 836 69

Alendronate is an aminobisphosphonate that inhibits bone resorption in osteoporotic humans and rats but does not induce osteomalacia. Several bisphosphonates, including alendronate, also have direct positive actions on osteoblasts, bone formation, and mineralization. We studied the effects of alendronate on skeletal development in adolescent male rats during chronic alcohol intake. Four groups of age- and weight-matched male Sprague-Dawley rats (35 days of age) were fed the Lieber-DeCarli diet containing 36% of calories as EtOH (E), the EtOH diet plus 60 mg/kg alendronate (EA) every other day intraperitoneally (ip), an isocaloric diet (I), or the isocaloric diet plus 60 mg/kg alendronate (IA) every other day ip. Body weight, femur length, serum levels of osteocalcin (OC), insulin-like growth factor 1 (IGF-1), testosterone, and luteinizing hormone (LH); femur distal metaphyseal and middiaphyseal bone mineral density (BMD) and tibial metaphyseal gene expression for alpha-1-type I collagen (Col I), OC, and bone alkaline phosphatase (AP); and femur strength by four-point bending to failure were measured after 28 days of feeding and alendronate injections. Serum alcohol levels at death were 156 +/- 13 mg/dl (E) and 203 +/- 40 mg/dl (EA). Alendronate given to alcohol-fed rats increased metaphyseal BMD by more than 3-fold over rats fed alcohol alone. Alendronate given to isocaloric pair-fed rats increased metaphyseal BMD by more than 2.5-fold over rats fed the isocaloric diet alone. Cortical BMD was reduced by alcohol but was increased by alendronate. Alcohol consumption reduced serum IGF-1 levels, and alendronate increased IGF-1 levels in alcohol-fed rats. Serum OC, testosterone, and LH were unaffected by alcohol and alendronate. Quantitative dot blot hybridization using rat complementary DNA (cDNA) probes and normalization against 18S subunit ribosomal RNA (rRNA) levels revealed no changes in tibial metaphyseal gene expression for type I collagen, osteocalcin, or alkaline phosphatase. Alcohol significantly reduced the biomechanical properties of the femurs that were partially compensated by alendronate. Chronic alcohol consumption uncouples formation from ongoing resorption, and resorption is inhibited by alendronate. However, alendronate's positive effects on osteoblast-mediated mineralization during chronic alcohol consumption point to the potential use of bisphosphonates in the treatment of decreased bone formation secondary to alcohol-induced diminished osteoblast function.
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PMID:Alendronate administration and skeletal response during chronic alcohol intake in the adolescent male rat. 1102 58

The hypothesis that growth hormone (GH) up-regulates the expression of enzymes, matrix proteins, and differentiation markers involved in mineralization of tooth and bone matrices was tested by the treatment of Lewis dwarf rats with GH over 5 days. The molar teeth and associated alveolar bone were processed for immunohistochemical demonstration of bone morphogenetic proteins 2 and 4 (BMP-2 and -4), bone morphogenetic protein type IA receptor (BMPR-IA), bone alkaline phosphatase (ALP), osteocalcin (OC), osteopontin (OPN), bone sialoprotein (BSP), and E11 protein (E11). The cementoblasts, osteoblasts, and periodontal ligament (PDL) cells responded to GH by expressing BMP-2 and -4, BMPR-IA, ALP, OC, and OPN and increasing the numbers of these cells. No changes were found in patterns of expression of the late differentiation markers BSP and E11 in response to GH. Thus, GH evokes expression of bone markers of early differentiation in cementoblasts, PDL cells, and osteoblasts of the periodontium. We propose that the induction of BMP-2 and -4 and their receptor by GH compliments the role of GH-induced insulin-like growth factor 1 (IGF-1) in promoting bone and tooth root formation.
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PMID:Growth hormone induces bone morphogenetic proteins and bone-related proteins in the developing rat periodontium. 1139 84


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