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M Muramatsu

Publications and source records attributed to M Muramatsu.

At least 91 records · Page 5Linked to original sources
PubMed2000

Efp as a primary estrogen-responsive gene in human breast cancer.

We have previously isolated the efp (estrogen-responsive finger protein) that is required for the normal estrogen-induced cell proliferation. Here, we show the genomic organization of the human efp gene which consists of nine exons. The efp mRNA was expressed in human breast tumors and the estrogen-induced expression of the efp was found in MCF-7 human breast cancer cells. Moreover, efp promoter activity was enhanced through the estrogen-responsive element dependent on estrogen and estrogen receptor. These results suggest that the efp can mediate estrogen actions such as cell growth in human breast cancer as a primary responsive gene.

Breast Neoplasms↗
PubMed2000

Application of Carbopol to controlled release preparations I. Carbopol as a novel coating material.

We investigated the application of Carbopol(R) (CP) as a novel coating material prepared with various grades of CP having different degrees of cross-linking and molecular weights. Viscosity and spray mist size of CP aqueous solutions at various concentrations of CP were measured. Core tablets containing theophylline (TP), as a model drug, were coated with CP at various coating ratios. The TP release profile from the CP-coated tablets was studied by the JP13 paddle method. CP tablets were prepared by compressing CP powder, and the swelling behavior of the CP tablets in JP 1st fluid, purified water, and JP 2nd fluid was observed. The spray mist size of all CP aqueous solutions was small at a concentration of 1% and below, and drastically increased over a concentration of 1%. This result suggests that the appropriate concentration of the CP solution for coating is 1% or below. Sustained release of TP from the CP-coated tablets at a coating ratio of only 3% was observed in the JP 1st fluid and purified water, although fast release was observed in the JP 2nd fluid. The fast release in the latter fluid may be due to the fact that CP is an acid material. These results suggest that it is feasible to control the drug release by use of an extremely small amount of CP coating and that CP is useful as a novel coating material.

Acrylic Resins↗
PubMed2000

Estrogen receptors: how do they control reproductive and nonreproductive functions?

Three aspects of recent development in estrogen receptor research will be discussed in this review. First, since the discovery of the second estrogen receptor, ERbeta, a new era has begun in this field. The presence of another receptor for estrogen having different tissue distribution and molecular specificity has posed a question as to the authenticity of the hitherto believed interpretation of the diverse actions of estrogen in different organs of both sexes. Ongoing studies, however, seem on the way of clarifying these new complex puzzles caused by the appearance of the new actor. Recent data with knockout mice for these genes are analyzed and discussed. Second, the mechanism of estrogen receptor action as a ligand-dependent transcription factor has been much more clarified these several years since the discovery of coactivators of steroid receptors which transmit the effect of ER to the transcription initiation complex. This may also open a way to understand the remodeling of chromatin to an active form which has long been sought. Third, the downstream genes of ER are now being isolated and characterized, which is mandatory for the global understanding of the estrogen action during the development and function of an individual animal. This approach, which has been most difficult, will now become more popular in future as newer technologies for this develop.

Animals↗
PubMed2000

Identification and characterization of human ZNF274 cDNA, which encodes a novel kruppel-type zinc-finger protein having nucleolar targeting ability.

A human cDNA encoding a novel zinc-finger protein, ZNF274, was identified by the "nuclear transportation trap" method (Ueki, N., Oda, T., Kondo, M., Yano, K., Noguchi, T., and Muramatsu, M., 1998, Nat. Biotechnol. 16: 1338-1342). Based on sequence analysis of the full-length cDNA, this novel gene has two alternative splicing forms, ZNF274a and ZNF274b, which encode putative proteins of 621 and 584 amino acids, respectively. ZNF274a contains five C2H2-type zinc-finger motifs, two KRAB-A (Kruppel-associated box) domains, and one leucine-rich domain. ZNF274b lacks the first KRAB-A domain at the N-terminus. ZNF274 mRNA is detected in various human tissues by Northern analysis. The ZNF274 gene is mapped distal to marker RP S28 1 in the human chromosome 19qter region, by RH mapping. The KRAB domains of ZNF274 exhibited transcription repressor activity when tested in GAL4 fusion protein assays. EGFP-ZNF274 fusion protein expressed in COS7 cells predominantly localized to the nucleoli. A series of deletion constructs revealed that a minimal domain consisting of the third and fourth zinc-fingers possesses nucleolar targeting ability. These results suggest that ZNF274 is a ubiquitous transcription repressor that plays a role in the nucleoli.

Alternative Splicing↗
PubMed2000

Association of estrogen receptor beta gene polymorphism with bone mineral density.

Chromosomal mapping of the human estrogen receptor beta (ERbeta) gene by fluorescence in situ hybridization (FISH) reveals that ERbeta is located at human chromosome 14, region q23-24.1, where the aberration of DNA copy number in the bone disorders is frequently involved. Then, we investigated the association between dinucleotide (cytosine-adenine; CA) repeat polymorphism located in the flanking region of ERbeta gene and bone mineral density (BMD) in 204 healthy postmenopausal Japanese women. The genotype was classified into "A" through "O" according to the number of the repeats, from 18 to 32. BMD was expressed in Z score (a deviation from the weight-adjusted average BMD of each age using the standard deviation as a unit). When we separate the subjects into two groups bearing at least one I allele (26 CA repeats) and those who did not, the former subjects had significantly higher Z score of L2-4 BMD (mean +/- standard deviation; 0.674 +/- 1.53 vs 0.128 +/- 1.38; P = 0.027). These data suggest that genetic variation at the ERbeta locus may be associated with some determinants for BMD and the possible involvements of this polymorphism in the cause of postmenopausal osteoporosis in Japanese women.

Base Sequence↗
PubMed2000

Identification of a novel 70 kDa protein that binds to the core promoter element and is essential for ribosomal DNA transcription.

Mammalian ribosomal RNA genes (rDNA) are transcribed by RNA polymerase I and at least two auxiliary factors, UBF and SL1/TFID/TIF-IB. It has also been reported that an additional factor(s) is required to reconstitute efficient initiation of rDNA transcription in vitro, depending upon the procedures of chromatographic separation. In an attempt to elucidate the molecular identity of such yet uncertain activities, we have developed agarose gel shift and UV cross-linking assays to detect proteins directly bound to the core promoter region of murine rDNA. With these techniques, we identified a 70 kDa protein (p70) in the flow-through fraction of a phosphocellulose column (TFIA-fraction). Interestingly, the binding of p70 to the rDNA core promoter was observed only in the presence of the SL1-containing fraction. The probable human orthologue of p70 was also detected in HeLa cells. Consistent with the observation that p70 bound to the core promoter only in the presence of the TFIA- and SL1-fractions, alteration of DNase I footprint pattern over the core promoter element was demonstrated by cooperative action of the TFIA- and SL1-fractions. A reconstituted in vitro transcription assay with further purified p70 indicated that p70 was required for accurate initiation of rDNA transcription. These results indicate that the p70 identified recently by the current DNA-binding experiments represents a novel transcription factor in rDNA transcription.

DNA, Ribosomal↗
PubMed2000

Chymase as a proangiogenic factor. A possible involvement of chymase-angiotensin-dependent pathway in the hamster sponge angiogenesis model.

We investigated the profound involvement of chymase, an alternative angiotensin II-generating enzyme, in angiogenesis using a hamster sponge implant model. In vivo transfection of human pro-chymase cDNA or a direct injection of purified chymase into the sponges implanted resulted in marked increment of hemoglobin contents in the sponge granuloma tissues, demonstrating that chymase has an ability to elicit angiogenesis and is a potent angiogenic factor. Daily injection of basic fibroblast growth factor into the sponges implanted also induced angiogenesis, which was suppressed by the treatment with chymostatin, an inhibitor of chymase, or TCV-116, an antagonist of angiotensin II (Ang II) type 1 receptor. Expression of chymase mRNA and production of Ang II in the granuloma tissues were enhanced by the stimulation with basic fibroblast growth factor. Chymase activity in the sponge granulomas increased in parallel with the rise in hemoglobin contents, and mast cells observed in the granuloma tissues were positively stained with anti-chymase antibody. Exogenous administration not only of Ang II but of angiotensin I (Ang I) directly into the sponges could enhance angiogenesis. Chymostatin inhibited the angiogenesis induced by Ang I but not Ang II, suggesting the presence of a chymase-like Ang II-generating activity in the sponge granulomas. Our results may suggest a potential ability of chymase to promote angiogenesis through the local chymase-dependent and angiotensin-converting enzyme-dependent Ang II generating system in pathophysiological angiogenesis.

Angiotensin I↗
PubMed2000

The cell cycle control gene ZAC/PLAGL1 is imprinted--a strong candidate gene for transient neonatal diabetes.

We describe a screen for new imprinted human genes, and the identification in this way of ZAC (zinc finger protein which regulates apoptosis and cell cycle arrest)/ PLAGL1 (pleomorphicadenoma of the salivary gland gene like 1) as a strong candidate gene for transient neonatal diabetes mellitus (TNDM). To screen for imprinted genes, we compared parthenogenetic DNA from the chimeric patient FD and androgenetic DNA from hydatidiform mole, using restriction landmark genome scanning for methylation. This resulted in identification of two novel imprinted loci, one of which (NV149) we mapped to the TNDM region of 6q24. From analysis of the corresponding genomic region, it was determined that NV149 lies approximately 60 kb upstream of the ZAC / PLAGL1 gene. RT-PCR analysis was used to confirm that this ZAC / PLAGL1 is expressed only from the paternal allele in a variety of tissues. TNDM is known to result from upregulation of a paternally expressed gene on chromosome 6q24. The paternal expression, map position and known biological properties of ZAC / PLAGL1 make it highly likely that it is the TNDM gene. In particular, ZAC / PLAGL1 is a transcriptional regulator of the type 1 receptor for pituitary adenylate cyclase-activating polypeptide, which is the most potent known insulin secretagog and an important mediator of autocrine control of insulin secretion in the pancreatic islet.

Cell Cycle↗
PubMed2000

Methylation and downregulated expression of mac25/insulin-like growth factor binding protein-7 is associated with liver tumorigenesis in SV40T/t antigen transgenic mice, screened by restriction landmark genomic scanning for methylation (RLGS-M).

Restriction landmark genomic scanning for methylation (RLGS-M) was used to detect alterations in DNA methylation associated with murine SV40 T/t antigen-induced hepatocarcinogenesis. An altered locus/spot (S130) was cloned and found to correspond to sequences in the 5' flanking region and 5' portion of the cDNA for the murine mac25/insulin-like growth factor binding protein-7 (Igfbp-7) gene. IGFBPs are believed to be capable of binding insulin, Igf1, and Igf2 and modulating mitogenic effects. Previous studies have shown that Igf2 has an important role in promoting liver tumorigenesis. Quantitative PCR was used to access the methylation status of the NotI site just 5' to the coding region and the expression level of the mac25/igfbp-7 gene. The results indicated that the degree of methylation was inversely related to the expression level and is consistent with a role for DNA methylation in silencing mac25/Igfbp-7 gene expression and function for mac25/Igfbp-7 as a tumor suppressor gene.

Animals↗
PubMed2000

cDNA cloning, expression profile, and genomic structure of human and mouse RNF10/Rnf 10 genes, encoding a novel RING finger protein.

RING finger (C3HC4-type zinc finger) is a variant zinc finger motif present in a new family of proteins including transcription regulators. A new member of the RING finger protein family was identified through a mouse expressed sequence tag (EST) database search, and its full-length cDNA was isolated from a mouse brain full length-enriched cDNA library. The gene was designated as Rnf10, for RING finger protein 10. The cDNA clone consists of 3110 nucleotides and encodes an open reading frame (ORF) of an 804-amino acid protein. A database search revealed that human KIAA0262 protein (accession number, D87451) has strong homology to mouse Rnf10. To confirm that mouse Rnf10 is the homolog or an isolog of human KIAA0262, a human RNF10 cDNA was cloned in our hands from a fetal brain cDNA pool. The newly isolated cDNA contained an ORF for 811 amino acids which had almost identical structure to mouse Rnf10 protein, indicating that the human ORF codes for RNF10 protein. This finding was also supported by comparative chromosome mapping in which both genes were localized in a conserved linkage homology region between mouse and human. Comparison of the RNF10 and KIAA0262 proteins revealed that both were transcribed from the same gene and that the longer RNF10 ORF would be the authentic form. The complete genomic organization of RNF10 was determined to consist of 17 exons spanning at least 40kb in the genome.

Amino Acid Sequence↗
PubMed2000

cDNA cloning, tissue expression, and chromosome mapping of human homolog of SOX18.

The SRY (sex-determining region Y) gene encodes a transcription factor characterized by a DNA-binding motif termed the HMG (high mobility group) domain. The SOX (Sry-box) genes comprise a large family related by homology to the HMG-box region. We isolated a cDNA clone with an open reading frame encoding a putative protein of 384 amino acids, which shared 83% identity to the mouse Sox18 protein. Northern blot analysis revealed that a 1.9-kb band of human SOX18 messenger RNAs was predominantly expressed in heart, although weak signals were seen in brain, liver, testis, and leukocyte. By polymerase chain reaction (PCR)-based analyses with both a human/rodent monochromosomal hybrid cell panel and a radiation hybrid panel, the gene was mapped to the chromosome 20q13.33 region.

Amino Acid Sequence↗
PubMed2000

cDNA cloning of a human RAB26-related gene encoding a Ras-like GTP-binding protein on chromosome 16p13.3 region.

Members of the RAB protein family are important regulators of vesicular fusion and trafficking. A putative new member of the RAB family of genes was identified through a public database search, and its full-length cDNA was isolated from a human fetal brain cDNA library. The predicted protein product of the gene consists of 190 amino acid residues and has 87% identity with rat Rab26. Thus, we designated this gene as the human RAB26-related gene. Reverse transcription-coupled polymerase chain reaction (RT-PCR) demonstrated that the RAB26-related messenger RNA was predominantly expressed in adult and fetal brain. Furthermore, an RT-PCR experiment for brain subregions showed that the mRNA was highly expressed in the amygdala, cerebellum, caudate nucleus, and hippocampus. By PCR-based analysis with both a human/rodent monochromosomal hybrid cell panel and a radiation hybrid panel, the gene was mapped to the chromosome 16p13.3 region between markers WI-7742 and WI-3061. The RAB26-related gene consists of eight exons that span about 44kb of the genome DNA.

Amino Acid Sequence↗
PubMed2000

cDNA cloning of a new member of the Ras superfamily, RAB9-like, on the human chromosome Xq22.1-q22.3 region.

Members of the RAB protein family regulate vesicular trafficking and reside in specific intercellular compartments. A new member of the RAB family was identified through a public database search, and its full-length cDNA was isolated from a human fetal brain cDNA library. The predicted protein product of the gene consists of 201 amino acid residues, and the protein has 86% similarity to human RAB9 at the amino acid level. We designated the new gene RAB9-like. Northern blot analysis showed that the gene was transcribed ubiquitously in various human tissues. A database search revealed that the gene is divided into three exons and spans approximately 7.2kb of the genome DNA of chromosome Xq22.1-q22.3 region.

Amino Acid Sequence↗
PubMed2000

cDNA cloning of a novel human gene NAKAP95, neighbor of A-kinase anchoring protein 95 (AKAP95) on chromosome 19p13.11-p13.12 region.

A-kinase anchoring protein 95 (AKAP95) is a nuclear protein which binds to the regulatory subunit (RII) of cyclic adenosine monophosphate (cAMP)-dependent protein kinase (PKA) and to DNA. A novel nuclear human gene which shares sequence homology with the human AKAP95 gene was identified by a nuclear transportation trap method. By polymerase chain reaction (PCR)-based analysis with both a human/rodent monochromosomal hybrid cell panel and a radiation hybrid panel, the gene was mapped to the chromosome 19p13.11-p13.12 region between markers WI-4669 and CHLC.GATA27C12. Furthermore, alignment with genomic sequences revealed that the gene and human AKAP95 resided tandemly only approximately 250 bp apart from each other. We designated this gene as neighbor of AKAP95 (NAKAP95). The exon-intron structure of NAKAP95 and AKAP95 was conserved, indicating that they may have evolved by gene duplication. The predicted protein product of the NAKAP95 gene consists of 646 amino acid residues, and NAKAP95 and AKAP95 had an overall 40% similarity, both having a potential nuclear localizing signal and two C2H2 type zinc finger motifs. The putative RII binding motif in AKAP95 was not conserved in NAKAP95. A reverse transcription coupled (RT)-PCR experiment revealed that the NAKAP95 gene was transcribed ubiquitously in various human tissues.

Amino Acid Sequence↗
PubMed2000

Effects of tea catechins on the ERE-regulated estrogenic activity.

Tea catechins exert many biological effects, including anticancer and antibacterial activities. Also, it is reported that some plant flavonoids exhibit estrogenic activity. In this study, we investigated estrogenic or antiestrogenic activities of catechins in HeLa cells transiently transfected with an estrogen response element (ERE)-regulated luciferase reporter and an estrogen receptor (ER) alpha or ERbeta expression vector. Catechins alone did not induce luciferase (luc) activity in either of the ERs. Addition of 17beta-estradiol (E2) plus epicatechin gallate (ECG) or epigallocatechin gallate (EGCG) at 5 x 10(-6) M resulted in significant decreases in the ERalpha-mediated luc activity compared with that of E2 alone. On the contrary, lower concentrations significantly increased the E2-induced luc activity. Similar effects were observed with tamoxifen. The ERbeta-mediated estrogenic activities were stimulated by catechins. In conclusion, some catechins, particularly EGCG, were antiestrogenic for ERalpha at higher doses, and co-estrogenic for ERalpha at lower doses and for ERbeta. The lower doses were found in human plasma after tea-drinking. In addition, some catechins may be antiendocrine disruptors because they suppressed bisphenol A-induced luc activities.

Catechin↗
PubMed2000

Cyclo-oxygenase-2 enhances basic fibroblast growth factor-induced angiogenesis through induction of vascular endothelial growth factor in rat sponge implants.

Angiogenesis is reportedly enhanced by prostaglandins (PGs). In the present study, we investigated whether or not cyclo-oxygenase (COX)-2 mediated angiogenesis in chronic and proliferate granuloma. In rat sponge implants, angiogenesis was gradually developed over a 14-day experimental period as granuloma formed. This angiogenesis was enhanced by topical injections of human recombinant basic fibroblast growth factor (bFGF). In sponge granuloma, mRNA of COX-1 was constitutively expressed, whereas that of COX-2 was increased with neovascularization in parallel with that of vascular endothelial growth factor (VEGF). Topical injections of bFGF increased the expression of COX-2 mRNA. bFGF-stimulated angiogenesis was inhibited by indomethacin or selective COX-2 inhibitors, NS-398, nimesulide, and JTE-522. The levels of PGE(2) and 6-keto-PGF(1alpha) in the sponge granuloma were increased with bFGF 13 fold and 9 fold, respectively, and these levels were markedly reduced by NS-398. The expression of VEGF mRNA in the granuloma was also enhanced by bFGF, and was reduced by NS-398. Topical injections of PGE(2) and beraprost sodium, a PGI(2) analogue, increased the expression of VEGF mRNA, with angiogenesis enhancement. The enhanced angiogenesis by bFGF was significantly inhibited by topical injections of VEGF anti-sense oligonucleotide. These results suggested that COX-2 may enhance bFGF-induced neovascularization in sponge granuloma by PG-mediated expression of VEGF, and that a COX-2 inhibitor would facilitate the management of conditions involving angiogenesis.

Animals↗
PubMed2000

Normalization and subtraction of cap-trapper-selected cDNAs to prepare full-length cDNA libraries for rapid discovery of new genes.

In the effort to prepare the mouse full-length cDNA encyclopedia, we previously developed several techniques to prepare and select full-length cDNAs. To increase the number of different cDNAs, we introduce here a strategy to prepare normalized and subtracted cDNA libraries in a single step. The method is based on hybridization of the first-strand, full-length cDNA with several RNA drivers, including starting mRNA as the normalizing driver and run-off transcripts from minilibraries containing highly expressed genes, rearrayed clones, and previously sequenced cDNAs as subtracting drivers. Our method keeps the proportion of full-length cDNAs in the subtracted/normalized library high. Moreover, our method dramatically enhances the discovery of new genes as compared to results obtained by using standard, full-length cDNA libraries. This procedure can be extended to the preparation of full-length cDNA encyclopedias from other organisms.

Animals↗