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)

Here we report that bone morphogenetic proteins 2 and 3 (BMP-2 and BMP-3) induced marked expression of c-fos mRNA in a biphasic manner, i.e. the late phase (48 to 60 h) as well as the immediate-early phase (0.5 h), in murine osteoblastic MC3T3-E1 cells in vitro. The BMP-induced late phase c-fos gene expression was temporally associated with the onset of marked expression of the genes for osteocalcin and alkaline phosphatase, differentiation markers of mature osteoblasts. In contrast, none of TGF-beta 1, 10% FBS, IGF-I and IGF-II, which induced only the immediate-early c-fos mRNA expression, stimulated the expression of osteocalcin and alkaline phosphatase genes. These data suggest that in osteoblasts BMP-2 and BMP-3 induce the late phase expression of c-fos, which may play a role in transcriptional activation of the genes involved in differentiation of osteoblasts.
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PMID:Bone morphogenetic proteins (BMP-2 and BMP-3) induce the late phase expression of the proto-oncogene c-fos in murine osteoblastic MC3T3-E1 cells. 146 69

In bone forming cartilage in vivo, cells undergo terminal differentiation, whereas most of the cells in normal articular cartilage do not. Chondrocyte hypertrophy can be induced also in vitro by diffusible signals. We have identified growth factors or hormones acting individually on 17-d chick embryo sternal chondrocytes cultured in agarose gels under strictly serum-free conditions. Insulin-like growth factor I or insulin triggered the first steps of chondrocyte maturation, i.e., cell proliferation and increased matrix deposition while the chondrocytic phenotype was maintained. However, cells did not progress to the hypertrophic stage. Proliferation and stimulated collagen production was preceded by a lag period, indicating that synthesis of other components was required before cells became responsive to insulin-like growth factor I or insulin. Very small amounts of FBS exerted effects similar to those of insulin-like growth factor I or insulin. However, FBS could act directly and elicited hypertrophy when constituting greater than 1% of the culture media. Basic FGF has been claimed to be the most potent chondrocyte mitogen, but had negligible effects under serum-free conditions. The same is true for PDGF, a major serum-mitogen. Under the direction of thyroxine, cells did not proliferate but became typical hypertrophic chondrocytes, extensively synthesizing collagen X and alkaline phosphatase.
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PMID:Induction of proliferation or hypertrophy of chondrocytes in serum-free culture: the role of insulin-like growth factor-I, insulin, or thyroxine. 173 18

Two established osteogenic cell lines (NY, MC 3 T3-E 1) were used in vitro to determine the biocompatibility of glass ceramics and their effect on initial calcification of osteogenic cells. Morphological study of the cell under the phase-contrast microscopy and histochemical staining were applied as follows. First, glass ceramic granules were placed in 60 mm dishes, and cells were suspended in the dishes in alpha-MEM supplemented with 10% FBS (basic medium) or medium with 50 micrograms/ml of L-ascorbic acid added. After 8 or 14 day of culturing, calcium formation was tested by von-Kossa's staining. Also, alkaline phosphatase staining was performed by the azo-dye method. As controls, cultures in dishes without glass ceramic granules were stained at the same time. The results obtained in the experimental culture were as follows. 1. Phase contrast microscopy showed that contacts with glass ceramics did not cause cellular death or degeneration. 2. In both cell cultures with the glass ceramics the von-Kossa reaction was positive as early as the 8th day. 3. The alkaline phosphatase reaction on the 8th day occurred only in MC 3 T3-E 1. The reaction was localized on fibroblastic cells which proliferated three-dimensionally around glass ceramics, and on small polyhedral cells situated relatively for apart from the ceramics. 4. On the 14th day, the MC 3 T 3-E 1 formed large nodules around the glass ceramics, and they were stained uniformly positive by von-Kossa's method. The alkaline phosphatase-positive cells extended spoke-like forms. 5. In medium with L-ascorbic acid, growth of NY was inhibited, After being cultured for 14 days, abundant von-Kossa positive reaction was found around glass ceramics in both cells. In MC 3 T 3-E1 on the 8th days, the alkaline phosphatase reaction was stronger with glass ceramics than with basic medium only. On the contrary, in the control cultures of both cells there was negative von-Kossa reaction during the culture period. The above results showed that glass ceramic granules have the biocompatibility needed for bone grafts, and they facilitated calcification of MC 3 T 3-E 1 in culture.
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PMID:[Basic studies on glass ceramics. 3. Influence on calcification of osteogenic cells in vitro]. 213 79

In order to clarify the effects of androgens and insulin (Ins) on the growth and regeneration of bone in growing rats, and to examine the interaction of the two hormones on the bone growth and regeneration, I carried out both in vivo and in vitro experiments using male rats and clonal osteoblastic cells, respectively. In vivo: 1) Three week-old male rats were castrated, and one week after the castration two holes were drilled into their calvariae, followed by subcutaneous administration of 2 mg/kg of testosterone propionate (TP) and/or 20 mg/kg of cyproterone acetate (CPA). After the daily administration of the drugs for two weeks, the calvariae containing wound holes were isolated, and a soft X-ray photograph was taken. The area of the hole in the X-ray film was measured. The calcium (Ca) and the hydroxyproline (HP) contents and alkaline phosphatase (ALPase) activity in the wound and non-wound portions of the calvariae were also determined. 2) Streptozotocin (STZ, 80 mg/kg) was administered intravenously to immature male rats (25-day-old); and three days after the administration, wound holes were made in their calvariae. Ins (10 units/kg) and/or TP (2 mg/kg) were/was administered daily for two weeks starting two weeks after the operation. The length and weight of the femur, and the area of the hole of the calvariae seen in a soft X-ray photograph were measured. The Ca and HP contents in the wound portion, and serum Ca and phosphate (P) levels and ALPase activity were also determined. In vitro: Mouse clonal osteoblastic cells (MC3T3-E1) were incubated in alpha-MEM mudium containing 10% FBS or 0.1% BSA with or without 10(-9)-10(-6) M TP and/or 10(-9)-10(-6) M Ins, the number of cells was counted, and [3H] thymidine incorporation into the cells was assayed for assessment of DNA synthesis. ALPase activity of the cells was also assayed. The results obtained were as follows: 1. The reduction in the wound-hole area was significantly delayed after the castration and was accelerated by TP. This effect of TP was inhibited about 60% by the simultaneous administration of CPA, though this inhibition was not statistically significant. 2. The reduction in HP content of the wound portion by castration was inhibited by TP, and this effect was antagonized by CPA.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[Role of testosterone propionate and insulin in the regeneration and growth of bone]. 215 2

A 35-years old female with Jordans' anomaly was reported. She had been treated for diabetes mellitus and hypertension at another hospital. She was admitted to our hospital for operation for diabetic retinopathy on July 9, 1992. Wright-Giemsa stained peripheral blood smear revealed multiple vacuoles in the cytoplasm of the granulocytes and monocytes. Histochemical studies of these vacuoles showed positive for Sudan III but negative for peroxidase, alkaline phosphatase and PAS staining. Electron microscopic examination revealed that lipid containing vacuoles had no clear membrane and were not associated with cell organelles. Laboratory findings of the serum showed hyperglycemia (FBS 188mg/dl), high HbA1c level (9.4%) and mild type IIa hyperlipidemia. Abdominal sonogram and abdominal CT showed no remarkable abnormalities except for mild fatty liver. Her elder sister and daughter had similar morphological findings in granulocytes, monocytes and lymphocytes.
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PMID:[A case of Jordans' anomaly]. 786 17

Osteoid nodules form in cultures of fetal rat calvarial (RC) cells grown in medium containing 10% FBS and 50 micrograms/ml of ascorbic acid. When 10 mM beta-glycerophosphate (beta-GP) is added, osteoid nodules mineralize in two phases: an initiation phase, which is dependent upon alkaline phosphatase activity for conversion of beta-GP to P(i), and a progression phase that proceeds independently of alkaline phosphatase activity and does not require exogenous phosphate. We have now used this system to investigate the effects of fluoride (F-) on mineralization. In cultures in which osteoid was formed and mineralization initiated in the presence of F-, a dose-dependent inhibition of the initiation of mineralization occurred over a concentration range of 25-500 microM F- (p < 0.001 in all cases). The initiation of mineralization was not inhibited if F- was removed from the cultures at the time when mineralization was initiated with beta-GP. In osteoid nodules grown in the absence of F-, addition of F- resulted in a dose-dependent inhibition of the initiation of mineralization, with significant decreases in 45Ca uptake occurring at F- concentrations of 3 microM (p < 0.01) and higher. However, if F- was added to cultures after mineralization was initiated in the absence of F-, a stimulation of 45Ca uptake was observed at F- concentrations of 250 microM and above (p < 0.001). F- (1-1000 microM) did not affect the conversion of beta-GP to P(i) or alkaline phosphatase activity in the cultures.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Differential effects of fluoride during initiation and progression of mineralization of osteoid nodules formed in vitro. 826 27

The purpose of this study is to clarify the role of retinoic acid (RA) in the mechanism of form-deprivation myopia (FDM) in the chick. FDM was induced in two-day old chicks by placement of a translucent plastic goggle over one eye, with the contralateral eye used as a control. After 12 days, the chicks were euthanized. RNA was extracted from scleras in the posterior segments, transcribed into cDNA, and amplified by PCR with primers specific for retinoic acid receptor (RAR) beta. G3PDH was used as a reference gene for normalization. The effects of RA, with or without TGF-beta, on the proliferation of scleral chondrocytes and scleral fibroblasts from 17-day chick embryos were studied by use of a colorimetric assay, and the alkaline phosphatase activities of those cells also studied. Furthermore, RAR beta expression in response to RA in cultured scleral cells was studied. As a result, RT-PCR products of the expected sizes were obtained from scleras from the myopic and control eyes. Expression of RAR beta in the myopic scleras was significantly higher than that in the controls. The proliferation of scleral chondrocytes and scleral fibroblasts was inhibited by treatment with RA in a dose-dependent manner (in 10% FBS). In the presence of TGF-beta (in 0.5% FBS), RA treatment stimulated the proliferation of scleral chondrocytes but inhibited the proliferation of scleral fibroblasts. RA induced alkaline phosphatase activities in both the scleral chondrocytes and scleral fibroblasts. RAR beta expression was induced by RA in cultured scleral cells. These results demonstrate that RA appears to play a role in the mechanism of FDM in the chick. However, it is also possible that the changes in the expression of RAR beta were secondary events related to other mechanisms responsible for ocular enlargement.
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PMID:In vivo and in vitro association of retinoic acid with form-deprivation myopia in the chick. 894 51

Periodontal regeneration is a complex process that requires coordinated responses from several cell types within the periodontium. It is generally accepted that the periodontal ligament (PDL) has a heterogeneous cell population, where some of the cells may be capable of differentiating into either cementoblasts or osteoblasts. Thus, it has been hypothesized that PDL cells play a role in promoting periodontal regeneration. However, definitive evidence to support this concept is lacking. Previously, we reported that PDL cells induce biomineralization as determined by Von Kossa histochemistry and transmission electron microscopy. To further determine the osteoblast-like properties of PDL cells, human PDL cells were exposed to dexamethasone (DEX) in order to promote an osteoblast phenotype, and then cell activity monitored during mineral nodule formation in vitro. For mineralization studies, cells were cultured in DMEM containing 10% FBS and a) vehicle only; b) ascorbic acid (50 micrograms/ml) and beta-glycerophosphate (10 mM); or c) ascorbic acid, beta-glycerophosphate and DEX (100 nM) for 30 days. In addition, the effects of DEX on PDL cells in non-mineralizing media were determined. Cells were stained weekly to evaluate mineral-like nodules, using the Von Kossa method. Northern blot analyses for mRNA steady state levels for several bone-associated proteins, i.e., osteopontin (OPN), bone sialoprotein (BSP), alkaline phosphatase (ALP), osteocalcin (OCN), alpha 2(1)(type 1) collagen and osteonectin (ON), were performed. DNA levels were also determined during the 30-day mineralization period. Under phase contrast microscopy, PDL cells in non-mineralizing media treated with DEX exhibited a more spindle-shaped morphology when compared with similar cells not exposed to DEX. Mineralizing conditions were required to induce mineral nodule formation. However, in this situation, mineral induction was independent of DEX; and furthermore, DEX-treated cells did not exhibit a different morphological pattern when compared with non-DEX treated cells. Mineral-like nodules were first seen at day 15, in concert with an increase followed by a decrease in expression of type I collagen and ON mRNA in both DEX-treated and non-treated cultures. Using Northern blot analysis for detection of specific proteins, we found that PDL cells did not express OPN, BSP, OCN, or ALP under any of the conditions used in this study. DEX did not alter DNA content in the cultures during the mineralization period. These results confirm that human periodontal ligament cells can be induced to mineralize in vitro and indicate that dexamethasone does not significantly alter the extent and pattern of mineralization.
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PMID:Expression of extracellular matrix proteins in human periodontal ligament cells during mineralization in vitro. 915 36

Recent studies indicate that vitamin D metabolites exert rapid effects on growth plate chondrocytes via changes in PG production and protein kinase C (PKC) activity. This suggests that these two products of vitamin D action may be interrelated. To test this hypothesis, we examined the effect of PGE2 on rat costochondral resting zone and growth zone cartilage cells and determined whether the effects of PGE2 are mediated by changes in the level of cAMP and/or PKC activity, whether there is a relationship between cAMP production and PKC activity, and whether cell maturation-specific effects are involved. Confluent, fourth passage resting zone and growth zone cartilage cell cultures were incubated in DMEM containing 10% FBS, 50 microg/ml vitamin C, and 1% antibiotics. The PGE2 concentration was varied from 0.007-15 ng/ml. Low concentrations of PGE2 caused a dose-dependent increase in cell number and [3H]thymidine incorporation and stimulated alkaline phosphatase specific activity. These effects were comparable in resting zone and growth zone cartilage cells at the same PGE2 concentrations. At higher concentrations, PGE2 caused a general increase in the synthesis of collagenase-digestible protein and noncollagenase-digestible protein in resting zone cartilage cells and of collagenase-digestible protein in growth zone cartilage cells, resulting in a net increase in the percent collagen synthesis for both cell types. cAMP production was increased over the entire range of chondrocyte response. Prevention of cAMP metabolism with the protein kinase A inhibitors H-8 and H-89 blocked the PGE2-dependent inhibition of PKC in resting zone cartilage cells in a dose-dependent manner. H-8 alone had no effect on PKC in resting zone cartilage cells, but stimulated PKC activity in growth zone cartilage cells; H-89 alone stimulated PKC activity in resting zone cartilage cells. These results suggest that low levels of PGE2 promote differentiation, whereas high doses promote an anabolic response; PGE2 increases cAMP production and PKC activity in a cell maturation-dependent manner; PGE2 exerts its effects via cAMP production and PKC activity; and regulation of PGE2-dependent PKC is via cAMP.
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PMID:The effect of prostaglandin E2 on costochondral chondrocyte differentiation is mediated by cyclic adenosine 3',5'-monophosphate and protein kinase C. 952 68

A continuous source of osteoblasts for normal bone maintenance, as well as remodeling and regeneration during fracture repair, is ensured by the mesenchymal osteoprogenitor stem cells of the bone marrow (BM). The differentiation and maturation of osteoprogenitor cells into osteoblasts are thought to be modulated by transforming growth factors-beta (TGF-beta1 and TGF-beta2) and TGF-beta-related bone morphogenetic proteins (BMPs). To define the responses of mesenchymal osteoprogenitor stem cells to several growth factors (GFs), we cultured Fischer 344 rat BM cells in a collagen gel medium containing 0.5% fetal bovine serum for prolonged periods of time. Under these conditions, survival of BM mesenchymal stem cells was dependent on the addition of GFs. Recombinant hTGF-beta1-F2, a fusion protein engineered to contain an auxiliary collagen binding domain, demonstrated the ability to support survival colony formation and growth of the surviving cells, whereas commercial hTGF-beta1 did not. Initially, cells were selected from a whole BM cell population and captured inside a collagen network, on the basis of their survival response to added exogenous GFs. After the 10-day selection period, the surviving cells in the rhTGF-beta1-F2 test groups proliferated rapidly in response to serum factors (10% FBS), and maximal DNA synthesis levels were observed. Upon the addition of osteoinductive factors, osteogenic differentiation in vitro was evaluated by the induction of alkaline phosphatase (ALP) expression, the production of osteocalcin (OC), and the formation of mineralized matrix. Concomitant with a down-regulation of cell proliferation, osteoinduction is marked by increased ALP expression and the formation of colonies that are competent for mineralization. During the induction period, when cells organize into nodules and mineralize, the expression of OC was significantly elevated along with the onset of extracellular matrix mineralization. Differentiation of BM mesenchymal stem cells into putative bone cells as shown by increased ALP, OC synthesis, and in vitro mineralization required the presence of specific GFs, as well as dexamethasone (dex) and beta-glycerophosphate (beta-GP). Although rhTGF-beta1-F2-selected cells exhibited the capacity to mineralize, maximal ALP activity and OC synthesis were observed in the presence of rhBMPs. We further report that a novel rhTGF-beta1-F2 fusion protein, containing a von Willebrand's factor-derived collagen binding domain combined with a type I collage matrix, is able to capture, amplify, and stimulate the differentiation of a population of cells present in rat BM. When these cells are subsequently implanted in inactivated demineralized bone matrix (iDBM) and/or diffusion chambers into older rats they are able to produce bone and cartilage. The population of progenitor cells captured by rhTGF-beta1-F2 is distinct from the committed progenitor cells captured by rhBMPs, which exhibit a considerably more differentiated phenotype.
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PMID:A recombinant human TGF-beta1 fusion protein with collagen-binding domain promotes migration, growth, and differentiation of bone marrow mesenchymal cells. 1041 2


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