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S Oida

Publications and source records attributed to S Oida.

At least 37 records · Page 2Linked to original sources
PubMed1999

Effects of mechanical stress on the mRNA expression of S100A4 and cytoskeletal components by periodontal ligament cells.

The periodontal ligament (PDL) functions under constant mechanical stress, and PDL cells obviously control PDL functions under such conditions. We have previously found that the mRNA expression of the Ca2+-binding protein S100A4 and beta-actin is higher in the PDL from erupted teeth than in the PDL from teeth under eruption. This suggested a role for S100A4 in the response of PDL cells to mechanical stress, possibly by coupling Ca2+ and the cytoskeletal system. In the present study, we investigated the direct effects of cyclical stretching on the mRNA expression of S100A4 and two cytoskeletal components (beta-actin and alpha-tubulin) by PDL cells. In Northern blotting analysis, the expression of S100A4, beta-actin, and alpha-tubulin mRNAs was higher in the PDL from fully erupted and functional bovine teeth than in partially erupted ones. Similarly, when bovine PDL cells were mechanically stimulated by means of the Flexercell Strain Unit, the expression of S100A4, beta-actin, and alpha-tubulin mRNAs increased over the control levels. The results of our present study indicate that S100A4 is involved in the responses of PDL cells to mechanical stress possibly by coupling Ca2+ to the cytoskeletal system in these cells.

Actins↗
PubMed1998

Gene expression of growth and differentiation factors-5, -6, and -7 in developing bovine tooth at the root forming stage.

Growth and differentiation factors (GDF)-5, -6, and -7 are members of the bone morphogenetic protein (BMP) family. Previous studies suggest their importance in bone development and in tendon/ligament morphogenesis. The cells of the dental attachment apparatus, cementum, periodontal ligament, and alveolar bone proper are derived from the dental follicle proper. In this study, we investigated the expression of GDF-5, -6, and -7 genes in tissues of the bovine incisor tooth germ at the root forming stage. The results demonstrate distinct expression of GDFs in both the dental follicle and the odontoblast layer. While GDF-5 and -6 mRNAs were expressed in both the dental follicle and the odontoblast layer, GDF-7 mRNA expression was detected only in the dental follicle. These results indicate that GDFs, expressed in the bovine tooth germ including the dental follicle, may be potent regulatory molecules in the development of the dental attachment apparatus.

Amino Acid Sequence↗
PubMed1998

cDNA cloning of S100 calcium-binding proteins from bovine periodontal ligament and their expression in oral tissues.

The periodontal ligament (PDL) is a unique tissue that is crucial for tooth function. However, little is known of the molecular mechanisms controlling PDL function. To characterize PDL cells at the molecular level, we constructed a cDNA library from bovine PDL tissue. We then focused on the isolation of S100 calcium-binding proteins (CaBPs), because they mediate Ca2+ signaling and control important cellular processes such as differentiation and metabolism. We screened the PDL cDNA library with a mouse S100A4 cDNA, and cloned the bovine cDNAs of two S100 CaBPs (S100A4 and S100A2). In northern blotting analysis, the highest expression of S100A4 was detected in PDL from erupted teeth (PDLE). PDL from teeth under eruption (PDLU) showed a lower expression of S100A4, and its expression in gingiva was faintly detectable. S100A4 expression was also high in the pulp tissue followed by the dental papilla of the tooth germ. S100A2 expression was high in PDLE and gingiva. Interestingly, only PDLE exhibited a high expression of both S100A4 and S100A2. PDLE also expressed the highest level of beta-actin, a target cytoskeletal protein for S100A4. It is conceivable that the high expression of S100A4 in PDLE is a result of the maturation of the PDL and/or a response to mechanical stress generated by mastication. Since there was a marked difference of S100A4 expression between PDL and gingiva, we propose that S100A4 could be a useful marker for distinguishing cells from these two tissues.

Amino Acid Sequence↗
PubMed1998

Expression of the mutant (1735T-DEL) tissue-nonspecific alkaline phosphatase gene from hypophosphatasia patients.

Hypophosphatasia (HOPS) is an inherited disorder characterized by defects in skeletal mineralization due to the deficiency of tissue-nonspecific alkaline phosphatase (TNSALP). To date, various mutations in the TNSALP gene have been identified. Especially, a deletion of T at position 1735 (1735T-del) located in exon 12 has been detected in three genetically unrelated Japanese patients, which seems to be one of the hot spots among the causative mutations in Japanese HOPS patients. 1735T-del causes a frame shift downstream from codon 503 (Leu), and consequently the normal termination codon at 508 is eliminated. Since a new inframe termination codon appears at codon 588 in the mutant DNA, the resultant protein is expected to have 80 additional amino acids. Expression of the mutant TNSALP gene using COS-1 cells demonstrated that the protein translated from the mutant 1735T-del had undetectable ALP activity, and its molecule size was larger than normal, as expected. Interestingly, an immunoprecipitation study of patients' sera using antibody against TNSALP revealed an abnormal protein which corresponded in size to the mutated TNSALP expressed by COS-1 cells, suggesting that the abnormal TNSALP is made by HOPS patients. The detection of TNSALP in cells transfected with 1735T-del using an immunofluorescent method exhibited only a faint signal on the cell surface, but an intense intracellular fluorescence after permeabilization.

Alkaline Phosphatase↗
PubMed1998

Amelogenin protein in tooth germs of the snake Elaphe quadrivirgata, immunohistochemistry, cloning and cDNA sequence.

In the snake, Elaphe quadrivirgata, the occurrence of amelogenin was immunohistochemically demonstrated in the enamel of developing tooth germs. Teeth of the snake are covered with a thin true enamel layer about 1-2 microns in thickness. Light and electron microscopic immunohistochemistry indicated an intense amelogenin immunoreactivity occurring in the enamel layer during the secretory stage of tooth development. Cloning and cDNA sequence of snake amelogenin was performed by RT-PCR. The amino acid sequence of the snake amelogenin cDNA--in its portion corresponding to the area from exon 5 to exon 7 of human X189 amelogenin gene--showed 45% homology with humans. Regions of both the N-terminus and C-terminus were well conserved. Furthermore, the positions of prolin in the amino acid alignment of the snake amelogenin corresponded well with those of human amelogenin. It is suggested that prolin is an essential constituent of amelogenin and therefore its positions in the molecule have been conserved after the evolutionary divergence of reptiles and mammals. This study using reptiles is the first detection of specific amelogenin immunoreactivity by high resolutional immunoelectron microscopy and the first cloning of amelogenin cDNA in a non-mammalian animal.

Amelogenin↗
PubMed1997

Direct action of nitric oxide on osteoblastic differentiation.

The effect of nitric oxide (NO) on osteoblastic differentiation was examined in cultured mouse osteoblasts. Interleukin-1beta and tumor necrosis factor-alpha expressed inducible NO synthase gene with little effect on constitutive NO synthase gene. These cytokines increased NO production, which was inhibited by L-NMMA pretreatment, and decreased alkaline phosphatase (AIPase) activity, which was not restored by L-NMMA. Furthermore, NO donors, sodium nitroprusside and NONOate dose-dependently elevated AIPase activity and expression of osteocalcin gene. These results suggest that NO directly facilitates osteoblastic differentiation and the cytokine-induced inhibition of AIPase activity is mediated via mechanism other than NO.

Alkaline Phosphatase↗
PubMed1997

Effects of ovariectomy on intestinal alkaline phosphatase expression in rats.

The aim of this study was to investigate the effects of ovariectomy (OVX) on intestinal alkaline phosphatase (ALP) activity in rats. The calcium (Ca) and phosphorus (P) contents and the mechanical strength of bone were decreased significantly by OVX. Two kinds of mRNAs of rat intestinal ALP (RTIN-1 and RTIN-2) were detected by reverse transcription-polymerase chain reaction (RT-PCR). In OVX rats, the level of RTIN-2 mRNA was lowered significantly, while that of RTIN-1 mRNA did not change. This result was compatible with the results of enzymatic activity. This finding suggests the possibility that OVX affects bone metabolism not only directly but also in an indirect way through an intestinal Ca and/or P metabolism via regulation of intestinal RTIN-2 ALP expression.

Alkaline Phosphatase↗
PubMed1996

Ectopic induction of cartilage and bone by bovine bone morphogenetic protein using a biodegradable polymeric reservoir.

Two kinds of bone morphogenetic protein (BMP) containing polymeric reservoirs made from poly(lactide-co-glycolide) (PLG) and a mixture of PLG/poly(ethylene glycol) (PEG) (PLG/PEG) were implanted into mice femoral muscles. In the PLG/PEG reservoir with BMP, bone formation was induced within 3 weeks. On the other hand, in the PLG reservoir with BMP scarcely any bone formation could be observed. The results suggest that the carrier system is most important for the development of BMP-induced bone formation and the PLG/PEG reservoir system is available for BMP delivery.

Animals↗
PubMed1996

Bone morphogenetic protein encapsulated with a biodegradable and biocompatible polymer.

To develop a controlled release system for bone morphogenetic protein (BMP), poly(DL-lactide-co-glycolide) (PLGA) capsules containing BMP were prepared by an interfacial precipitation method using a water-in-oil-in-water emulsion. The surface morphology, particle size distribution, and hydrolytic degradation rate of the PLGA capsules were examined. The encapsulation yield and release rate of BMP in vitro were measured using fluorescein isothiocyanate-labeled BMP. The amount of BMP released from PLGA capsules increased between days 3 and 5. In addition, the effectiveness of BMP encapsulated in PLGA to induce bone formation in vivo was also examined by subcutaneous implantation in rats. Complete digestion of the capsules and new bone formation including bone marrow were identified by histologic examination of harvested tissues at 3 weeks after implantation. These results demonstrated that encapsulation of BMP with PLGA could be a promising method to induce bone in clinics.

Animals↗
PubMed1996

Determination of enamel protein synthesized by recombined mouse molar tooth germs in organ culture.

Epithelial-mesenchymal interaction is a prerequisite for tooth morphogenesis. To study this interaction, inner enamel epithelium and dental papilla mesenchyme of molar tooth germs from a 16.5-day mouse embryo were dissociated enzymatically and cultured alone or after recombination. Characteristic matrix protein synthesized and secreted by recombined tooth germ was determined quantitatively by enzyme-linked immunosorbent assay. The protein was detected in the culture of recombined tooth germ but not of dissociated enamel epithelium alone. The amount of enamel protein increased until 8 days in culture. Morphological differentiation of the recombined epithelial rudiment into ameloblasts and enamel protein production were confirmed.

Ameloblasts↗
PubMed1996

Expression of mRNA encoding intestinal type alkaline phosphatase in rat liver and its increase by fat-feeding.

The presence of types of alkaline phosphatase (ALP) other than the tissue non-specific type enzyme in rat liver and its increase by fat feeding are known. In order to examine expression of intestinal type ALP in liver, specific oligonucleotide primers corresponding to two types of mRNAs of rat intestinal ALP (RTIN-1 and -2) were designed and amplified by means of the reverse transcriptase-polymerase chain reaction (RT-PCR). It was found that RTIN-1 mRNA was expressed only in the intestine but not in the liver, while RTIN-2 mRNA was expressed both in the intestine and in the liver. By fat feeding, expression of RTIN-1 mRNA increased in the intestine and that of RTIN-2 mRNA increased both in the intestine and in the liver. Thus, it was concluded that rat liver expressed one of the intestinal type ALP (RTIN-2) which was enhanced by fat feeding.

Alkaline Phosphatase↗
PubMed1996

Molecular structure of the mouse amelogenin genomic DNA.

A genomic DNA clone (14.5 kbp) for amelogenin, a tooth enamel specific protein, has been isolated from a mouse genomic library. The nucleotide structure of this DNA was determined by the polymerase chain reaction and sequence analysis. The result indicated that the cloned DNA contained all the exons in addition to approximately 5.5 kbp of upstream sequence.

Amelogenin↗
PubMed1996

Ovariectomy decreases osteogenetic activity in rat bone.

The purpose of this study was to investigate the effect of ovariectomy on osteoinductive activity in the bone in rat. Homograft implantation of decalcified humeral diaphysis from ovariectomized or sham-operated rats was performed and harvested after several time periods. A significant decrease in bone induction was found in terms of soft X-ray photography, alkaline phosphatase activity, mineral content and expression of osteocalcin (BGP; bone gla-protein) in the implants from the ovariectomized group in comparison to those from the sham-operated animals. This result suggested that the level of osteoinductive activity, probably due to bone morphogenetic protein, decreased in ovariectomized animals.

Alkaline Phosphatase↗
PubMed1995

Expression of prostaglandin E receptor subtypes in bone: expression of EP2 in bone development.

Prostaglandin (PG) E2 displays physiological and pharmacological action in various tissues including bone. It increases intracellular Ca, and stimulates or inhibits cAMP production through the PGE receptor subtypes EP1, EP2, and EP3, respectively. These receptor subtypes have been recently cloned. In the present study, we investigate the expression of these receptor subtypes in bone tissue. RT-PCR revealed that EP1, EP2, and EP3 were expressed in rat calvariae and that osteoblastic cells (MC3T3-E1) expressed EP1 and EP2. In situ hybridization analysis using cryosection of neonatal calvariae revealed that EP2 was expressed by osteoblasts and cells not in contact with bone, probably including preosteoblasts. EP2 expression was observed at an early stage in calvarial development, at 14 days prenatal. EP2 expression was also observed at day 3 in rat bone marrow cell culture in which bone-like mineralized nodules are formed at day 8. It has been established that PGE2 response accompanying cAMP production is one of the characteristics of osteoblasts. The present results indicate that this phenotype appears at an early stage of osteoblastic differentiation and bone development.

3T3 Cells↗
PubMed1995

Identification of bone-type alkaline phosphatase mRNA from human periodontal ligament cells.

Tissue-nonspecific-type alkaline phosphatase is found in the bone, liver, kidney, and other tissues, and its gene consists of 12 exons with the coding sequence beginning in the second exon. Recently, an alternative noncoding first exon was identified in the liver message which differed from that of the previously known osteoblast-derived cDNA sequence. Although these two mRNAs produce an identical protein, they have different promoter regions. The periodontal ligament tissue expresses a high level of alkaline phosphatase activity. To identify its mRNA type, we isolated a full-length cDNA for alkaline phosphatase from a cultured human periodontal ligament cell expression library, using bone-derived tissue-nonspecific alkaline phosphatase cDNA as a hybridization probe. The size of this clone was 2.5 kb, and its 5' and 3' untranslated sequences were identical to those of the human tissue-nonspecific type isolated from osteoblastic cells but not to those of the liver type. In addition, the same fragments as in bone-derived tissue-nonspecific-type cDNA were detected by the treatment of the cDNA clone with restriction enzymes Hinc II and Pst I. The results suggest that expression of the same alkaline phosphatase isozyme in human periodontal ligament cells may be regulated by the same transcriptional mechanism as in bone.

Alkaline Phosphatase↗