[Tissue factor pathway inhibitor (TFPI)].
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Factor Xa Inhibitors↗
Biomedical subjects
M Matsuo
Publications and source records attributed to M Matsuo.
Transforming activity of the RL-akt gene, a c-akt gene activated by long terminal repeat insertion in murine leukemia RL(male symbol)1 cells.
The unique antigen peptide pRL1 on BALB/c radiation-induced leukemia RL(male symbol)1 cells is derived from the normally untranslated 5' region of the mouse c-akt gene. Insertion of an endogenous long terminal repeat into the first coding exon of the gene resulted in the enhanced production of an altered akt protein, RL-akt, and creation of the tumor rejection antigen peptide pRL1. In this study, we constructed an RL-akt-expressing vector to investigate the transforming ability and anti-apoptotic activity of RK-akt in NIH/3T3 cells. RL-akt-expressing clones formed more colonies than did c-akt-expressing clones in soft agar and exhibited increased saturation density, a lower serum requirement for growth, and tumorigenicity on athymic nude mice. Immunoblot analysis of subcellular protein distribution showed that a considerable proportion of RL-akt was distributed in the membrane fraction. Thus, RL-akt expressed in NIH/3T3 cells appeared to behave like the v-akt oncoprotein. Furthermore, the RL-akt gene conferred resistance to the apoptosis induced by the calcium ionophore A23187 and by ultraviolet irradiation of NIH/3T3 cells. These findings indicate that the RL-akt gene is able to transform cells and exerts an anti-apoptotic effect on recipient cells, thereby implicating the gene in leukemogenesis of RL(male symbol)1 cells.
3T3 Cells↗
Prenatal diagnosis of a Japanese family at risk for Tay-Sachs disease. Application of a fluorescent competitive allele-specific polymerase chain reaction (PCR) method.
Tay-Sachs disease (TSD) is caused by mutation of the HEXA gene, which results in a deficiency of the alpha-subunit of hexosaminidase A. The major mutation in Japanese TSD is a G-to-T transversion at the 3'-splice site of intron 5. We established a fluorescent competitive allele-specific polymerase chain reaction (FCAS-PCR) method for detection of the mutation and applied it to prenatal diagnosis of a Japanese TSD family. FCAS-PCR distinguished the wild and mutant alleles clearly, with broad ranges in the amount of template DNA, the dNTP concentration, the MgCl2 concentration and the number of PCR cycles. After obtaining ethics committee approval and informed consent from the parents in the index family, chorionic villus sampling was performed. FCAS-PCR analysis using chorionic villus DNA disclosed that the fetus was homozygous for the mutation. To confirm the diagnosis, direct sequencing analysis of the genomic PCR fragment was performed, and showed the same results as those of the FCAS-PCR analysis. FCAS-PCR proved to be helpful for carrier screening and prenatal diagnosis in TSD families in the Japanese population. It would also be a useful DNA-diagnostic method for many other inherited disorders.
Adult↗
Study on mutations affecting the muscle promoter/first exon of the dystrophin gene in 92 Japanese dilated cardiomyopathy patients.
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Cardiomyopathy, Dilated↗
Synthesis and effects of novel thiazole derivatives against thrombocytopenia.
5-(2-Pyridylsulfonyl)-2-thiazolamine (2) was effective both in mitomycin C (MMC)-induced thrombocytopenia and in an animal model of idiopathic thrombocytopenic purpura (ITP). It also suppressed the increase of autoantibodies against platelets in the ITP model and showed no blood toxicity. Chemical modification of 2 led to the discovery of more potent compounds against MMC-induced thrombocytopenia.
Animals↗
Non-equivalent cooperation between the two nucleotide-binding folds of P-glycoprotein.
To identify the roles of the two nucleotide-binding folds (NBFs) in the function of human P-glycoprotein, a multidrug transporter, we mutated the key lysine residues to methionines and the cysteine residues to alanines in the Walker A (WA) motifs (the core consensus sequence) in the NBFs. We examined the effects of these mutations on N-ethylmaleimide (NEM) and ATP binding, as well as on the vanadate-induced nucleotide trapping with 8-azido-[alpha-32P]ATP. Mutation of the WA lysine or NEM binding cysteine in either of the NBFs blocked vanadate-induced nucleotide trapping of P-glycoprotein. These results suggest that if one NBF is non-functional, there is no ATP hydrolysis even if the other functional NBF contains a bound nucleotide, further indicating the strong cooperation between the two NBFs of P-glycoprotein. However, we found that the effect of NEM modification at one NBF on ATP binding at the other NBF was not equivalent, suggesting a non-equivalency of the role of the two NBFs in P-glycoprotein function.
ATP Binding Cassette Transporter, Subfamily B, Mem↗
Inhibition of linoleic acid hydroperoxide-induced toxicity in cultured human umbilical vein endothelial cells by catechins.
The protective effect of catechins, major components of green tea, was studied in cultured human umbilical vein endothelial cells exposed to toxicity induced by linoleic acid hydroperoxide (LOOH). In the case where cells were incubated in medium containing both LOOH and catechins, (+)-catechin (C) was effective in suppressing of LOOH-induced cytotoxicity, but (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECG), and (-)-epigallocatechin gallate (EGCG) had no effect. EGCG monoglucoside (EGCG-G1) and EGCG diglucoside (EGCG-G2), apophilic derivatives of EGCG, show a protective effect on LOOH-induced cytotoxicity when present at the time of treatment with LOOH. On the other hand, when cells were incubated with catechins for 24 h before treatment with LOOH there was no protection against the oxidative damage by LOOH. Furthermore, the interaction between catechins and alpha-tocopherol was examined under these culture conditions. C showed a synergistic effect with alpha-tocopherol in protecting against LOOH-induced damage. These results suggest that catechins interact with LOOH present in the medium or near the surface of membranes, but not with LOOH incorporated into cellular membranes and that catechins are able to interact with alpha-tocopherol to provide synergistic protection against the cytotoxicity of LOOH.
Catechin↗
Microsatellite instability in Japanese hereditary non-polyposis colorectal cancer does not induce mutation of a simple repeat sequence of the bax gene.
The identification of frameshift mutations in the coding region of the bax gene in Western cases of hereditary non-polyposis colorectal cancer provided evidence that the disease could be caused by the disruption of a tumor suppressor gene associated with microsatellite instability. In order to determine whether this observation could be extended to Japanese colorectal cancers, we analyzed the simple repeat sequence of (G)8 in the bax gene of tumor genomes from 15 cases of Japanese hereditary non-polyposis colorectal cancer that showed microsatellite instability in at least one of four examined microsatellite loci. None of 15 tumor DNA samples had a frameshift mutation in this region of the bax gene. Our results suggest that direct disruption of the bax gene is not a major factor responsible for carcinogenesis in Japanese hereditary non-polyposis colorectal cancers even though microsatellite instability is present.
Colorectal Neoplasms, Hereditary Nonpolyposis↗
Purification and molecular properties of ascorbate peroxidase from bovine eye.
Ascorbate peroxidase (APX) is a hydrogen peroxide-scavenging peroxidase which uses ascorbate (AsA) as the specific electron donor. APX has not been isolated in mammals. Ocular tissue contains AsA at high concentrations, and we detected APX activity in bovine retinal pigment epithelium (RPE) and choroid. We purified APX from bovine RPE and choroid by four chromatographic steps. The purified APX was a monomeric hemoprotein with a molecular mass of 43 kDa. The amino acid sequence of the amino-terminal region of the purified APX showed a high degree of homology to that of plants. The primary product of the APX reaction was identified as the monodehydroascorbate radical. The APX showed high specificity for AsA as an electron donor. This is the first isolation and characterization of APX from mammals, and its role in the protection against active species of oxygen in ocular tissue is discussed.
Amino Acid Sequence↗
Discovery of FR115092: a novel antinephritic agent.
A series of dapsone-related 4-aminopheynl and 2-aminothiazolyl derivatives was prepared, and their antinephritic activity and blood toxicity were evaluated. 5-(2-Pyridylsulfonyl)-2-thiazolamine (FR115092, 26) was effective against two nephritis models, namely graft-versus-host disease (GVHD) and autoimmune W/BF1 mice, and showed none of the blood toxicity observed with dapsone.
Anemia↗
Novel missense mutation in the HMG box of SOX9 gene in a Japanese XY male resulted in campomelic dysplasia and severe defect in masculinization.
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Amino Acid Substitution↗
The gene for mesomelic dysplasia Kantaputra type is mapped to chromosome 2q24-q32.
Mesomelic dysplasia Kantaputra type (MDK) (MIM *156232) is a new autosomal dominant skeletal dysplasia characterized by dwarfism, shortening of the forearms/lower-legs, carpal/tarsal synostosis, and dorsolateral foot deviation. We studied a Thai family in which 15 members in 3 generations were affected with MDK. With reference to the breakpoints of a balanced translocation [t(2;8)(q31;p21)] in patients from a previously reported Italian family with a skeletal dysplasia that appears similar to MDK, a linkage analysis was performed in the Thai family using 50 CA-repeat markers mapped to nearby regions (2q22-q34 and 8p24-p21) of the translocation breakpoints. The results clearly ruled out a linkage of MDK to marker loci at the 8p24-p21 region, whereas all nine affected members available for the study shared a haplotype at four loci (D2S2284, D2S326, D2S2188, and D2S2314) spanning about 22.7 cM in the 2q24-q32 region. The computer-assisted two-point linkage analysis revealed maximum logarithm of odds (lod) scores of 4.82, 4.21, 4.82, and 4.21 (theta = 0) at these loci, respectively. These data indicated that the MDK locus is in the vicinity of D2S2284 and D2S2188 loci that are most likely mapped to 2q24-q32.
Chromosome Mapping↗
Inhibition of leukotriene synthesis by terfenadine in vitro.
To determine the inhibitory mechanisms of terfenadine on the synthesis of leukotriene C4 (LTC4), an important mediator in allergic diseases, we evaluated the action of terfenadine on the IgE-dependent production of LTC4 in rat basophilic leukaemia 2H3 cells. Rat IgE-loaded cells were stimulated with anti-IgE in the presence or absence of various concentrations of terfenadine and the level of LTC4 released into the medium was measured by performing a specific radio immunoassay. Terfenadine inhibited the synthesis of LTC4 to 67.2% at a concentration of 5 microg/ml. LT synthesis was directly suppressed by inhibition of 5-lipoxygenase (5-LO) through calcium ion-independent mechanisms, and was also possibly suppressed by inhibition of cytosolic phospholipase A2 and 5-LO by blocking the influx of intracellular calcium ion that was initiated by IgE-related stimulation.
Animals↗
Effect of dexamethasone on leukotriene synthesis in DMSO-stimulated HL-60 cells.
Human leukemia (HL) 60 cells were differentiated by dimethylsulfoxide (DMSO) treatment to granulocyte-like cells, leukotriene (LT) synthesizing activity of which was increased in response to the differentiation of the cells. Four synthesizing enzymes, cytosolic phospholipase A2 (cPLA2), 5-lipoxygenase (5-LO), LTA4 hydrolase and LTC4 synthase, and an enzyme associated protein, 5-lipoxygenase activating protein (FLAP) are involved in the generation of LTC4 and LTB4. We examined the expression of messenger RNA (mRNA) for these LT synthesizing enzymes and an associated protein in DMSO differentiated HL-60 cells by reverse transcriptase polymerase chain reaction (RT-PCR). The production of LTC4 and LTB4, measured by radioimmunoassay (RIA), was increased after the incubation with DMSO for more than 3 days. Messenger RNA abundance for 5-LO, LTC4 synthase and LTA4 hydrolase was increased, that for FLAP was stable, but that for cPLA2 was decreased. These results indicate that DMSO induced increase of LT synthesis is associated with the increase of mRNA expression of 5-LO, LTC4 synthase and LTA4 hydrolase, although the precise regulatory mechanisms of the increased mRNA expression are not determined. We also investigated an action of dexamethasone (DEX) on DMSO-induced enhancement of LT synthesis. DEX suppressed DMSO induced increase of LTC4 synthesis, but rather enhanced DMSO induced LTB4 production. The DEX attenuated the DMSO-induced increase of mRNA expression for LTC4 synthase, but showed no effect on that for LTA4 hydrolase. The inhibition of LTC4 synthesis is associated with the suppression of mRNA expression for LTC4 synthase. However, increased LTB4 synthesis by DEX is regulated by the mechanisms which are independent from mRNA level of LTA4 hydrolase.
5-Lipoxygenase-Activating Proteins↗
Effects of aging and food restriction on the antioxidant enzyme activity of rat livers.
The effects of aging and food restriction on the activities and mRNA levels of antioxidant enzymes in rat livers were examined. Rats were fed ad libitum every day (AL) or ad libitum on every other weekday (FR). At 30 months of age, the catalase and glutathione peroxidase activities were lower, whereas the thiobarbituric acid (TBA) value, an index of lipid peroxidation of the AL rats, was higher than that at younger ages. At 33 months of age, copper/zinc superoxide dismutase (CuZnSOD), catalase, and glutathione peroxidase activities increased, and the TBA value of the FR rats remained unchanged as compared with those at younger ages. Until old age, food restriction gave rather decreasing effects on antioxidant enzyme activities. Furthermore, antioxidant enzyme activities and the TBA values of the FR rats were higher at the end of a fasting period than those at the end of a feeding period.
Aging↗
Properties of the respiratory NAD(P)H dehydrogenase isolated from the cyanobacterium Synechocystis PCC6803.
Activity staining with NADPH-nitroblue tetrazolium after native-PAGE of membrane proteins of Synechocystis PCC6803, solubilized with 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS), revealed four NAD(P)H dehydrogenase (NDH) activities; an NDH complex of the respiratory chain, a ferredoxin NADP+ reductase (FNR), a drgA product which oxidized both NADH and NADPH, and an uncharacterized NADH-specific enzyme. The NDH complex was purified with anion exchange and gel filtration chromatographies. The purified complex had a molecular mass of 376 kDa and was composed of 9 subunits. Western analysis showed that the complex contained the NDH-H subunit, but not NDH-A or B. The enzyme reduced ferricyanide much faster than plastoquinone and used NADPH as its preferred electron donor rather than NADH. The enzymatic activity was inhibited by diphenyleneiodonium chloride and salicylhydroxamic acid, but not by rotenone, p-chloromercuribenzoate, N-ethylmaleimide, flavon, dicumarol, or antimycin A. These results suggest that the purified complex is a hydrophilic subcomplex which contains an NADPH binding site and flavin, and is dissociated from a hydrophobic subcomplex, which contains quinone binding site.
Amino Acid Sequence↗
Isolation of a novel NAD(P)H-quinone oxidoreductase from the cyanobacterium Synechocystis PCC6803.
A novel NAD(P)H-quinone oxidoreductase (NQR) was isolated from the cyanobacterium Synechocystis PCC6803 by ion-exchange, affinity and gel-filtration chromatographies. Isolated NQR was found to be a drgA gene product that was a homodimer composed of 23-kDa subunits. It showed NAD(P)H-plastoquinone oxidoreductase activity with Km values for NADPH and NADH of 12 and 48 microM, respectively. The activity was inhibited by thiolmodifying reagents, but not by rotenone, amobarbital, salicylhydroxamic acid, dicumarol, flavone, or diphenyleneiodonium chloride. Therefore, the Cys-147 residue is probably involved in the catalytic reaction. The amino acid sequence of the purified NQR had some homology with those of NADH oxidase, NAD(P)H-flavin oxidoreductase, and nitroreductase but did not contain either an adenine-binding motif or a phosphate-binding motif, thus, it is a new type of NQR.
Amino Acid Sequence↗
Genetic variation in the promoter region of the beta-fibrinogen gene is associated with ischemic stroke in a Japanese population.
Evidence suggests that an allelic variation in the beta fibrinogen gene may confer an increased risk of coronary artery disease and stroke. The role of the beta fibrinogen gene polymorphism and fibrinogen levels in ischemic stroke has not been determined in Japanese, who are more prone to stroke than to coronary artery disease compared with Caucasians. We investigated the associations between ischemic stroke, plasma fibrinogen level, and a HaeIII restriction fragment length polymorphism (G/A(-455)) located at -455 bp from the start of transcription of the beta fibrinogen gene in 85 hypertensive patients with ischemic stroke (stroke group), 85 hypertensive patients without ischemic stroke (nonstroke group) and in 84 normotensive subjects matched for age, sex, and smoking status recruited at an annual health examination (normotensive group). The frequency of non-cutting allele (designated A(-455) allele) in the control group was 0.07 [95% CI: 0.03-0.11]; this value was significantly lower than that previously reported in Caucasians (0.19-0.26). The A(-455) allele frequency of the nonstroke group and stroke group were 0.08 [95% CI: 0.04-0.12] and 0.15 [95% CI: 0.10-0.21]. A(-455) allele frequency of the stroke group was significantly higher than that of the control group chi2 = 5.63, P= 0.018) and the nonstroke group chi2 = 4.00, P= 0.043). The mean +/- SD fibrinogen level was significantly higher in the stroke group than that in the normotensive group (277 +9/- 64 mg/dl versus 257 +/- 52 mg/dl, P < 0.03), but that of the nonstroke group was not significantly different compared with both normotensive and stroke groups. In conclusion, the positive association between the fibrinogen genotype G/A(-455) and ischemic stroke in hypertensive patients was independent of other risk factors. These results suggest that fibrinogen A(-455) allele may be an independent risk factor for ischemic stroke in the Japanese population.
Age Factors↗