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T Urano

Publications and source records attributed to T Urano.

At least 19 recordsLinked to original sources
PubMed2001

The profibrinolytic enzyme subtilisin NAT purified from Bacillus subtilis Cleaves and inactivates plasminogen activator inhibitor type 1.

In this report, we demonstrate an interaction between subtilisin NAT (formerly designated BSP, or nattokinase), a profibrinolytic serine proteinase from Bacillus subtilis, and plasminogen activator inhibitor 1 (PAI-1). Subtilisin NAT was purified to homogeneity (molecular mass, 27.7 kDa) from a saline extract of B. subtilis (natto). Subtilisin NAT appeared to cleave active recombinant prokaryotic PAI-1 (rpPAI-1) into low molecular weight fragments. Matrix-assisted laser desorption/ionization in combination with time-of-flight mass spectroscopy and peptide sequence analysis revealed that rpPAI-1 was cleaved at its reactive site (P1-P1': Arg(346)-Met(347)). rpPAI-1 lost its specific activity after subtilisin NAT treatment in a dose-dependent manner (0.02-1.0 nm; half-maximal effect at approximately 0.1 nm). Subtilisin NAT dose dependently (0.06-1 nm) enhanced tissue-type plasminogen activator-induced fibrin clot lysis both in the absence of rpPAI-1 (48 +/- 1.4% at 1 nm) and especially in the presence of rpPAI-1 (78 +/- 2.0% at 1 nm). The enhancement observed in the absence of PAI-1 seems to be induced through direct fibrin dissolution by subtilisin NAT. The stronger enhancement by subtilisin NAT of rpPAI-1-enriched fibrin clot lysis seems to involve the cleavage and inactivation of active rpPAI-1. This mechanism is suggested to be important for subtilisin NAT to potentiate fibrinolysis.

Bacillus subtilis↗
PubMed2001

Bezafibrate attenuates the overexpression of plasminogen activator inhibitor-1 messenger RNA by a combination of mono-unsaturated fatty acid and insulin in hepG2 cells.

The effects of bezafibrate (PPAR alpha activator) and troglitazone (PPAR gamma activator) on the expression of plasminogen activator inhibitor type-1 (PAI-1) in HepG2 cells were investigated. Exposure of the cells for 24 hours to either oleic acid or insulin showed no obvious effects on PAI-1 synthesis, whereas the combination of the two agents induced a 2.3-fold increase in PAI-1 synthesis, which was accompanied by a 3-fold increase in both the 2.2 kb and 3.2 kb forms of PAI-1 mRNA. This up-regulation of PAI-1 synthesis was attenuated by bezafibrate in a dose-dependent manner (1-100 microM) with 30% reversal at 100 microM. In contrast, troglitazone further stimulated PAI-1 synthesis to 140% of the level obtained in the presence of both oleic acid and insulin. This attenuation by bezafibrate and enhancement by troglitazone required the presence of both oleic acid and insulin. It is interesting that PAI-1 expression was affected so differently by these two PPAR activators.

Bezafibrate↗
PubMed2001

Dissociation of systemic and hippocampal modulation of rat locomotor activity by 5-HT(2C) receptors.

In the present study, the ability of 5-hydroxytryptamine(2C) (5-HT(2C)) receptors in the hippocampus to enhance locomotor activity in rats was investigated by local infusion. Intraperitoneal injection of the selective 5-HT(2C) antagonist SB 242084 (1 mg/kg) significantly increased rats motor activity, while the effects of non-selective 5-HT(2C) agonist m-chlorophenylpiperazine (m-CPP, 10 mg/kg; i.p.) on motor activity were lower than those of the control group. In the day hours, the local infusion of non-selective 5-HT(2C) agonist, m-CPP (1.0 mM) into the bilateral hippocampus via microdialysis probes increased locomotor activity in contrast with intraperitoneal injection. This increase was completely reversed by the combined infusion of the selective 5-HT(2C) antagonist SB 242084 (100 mM). In the night hours, the local infusion of SB 242084 (100 mM) into the bilateral hippocampus significantly inhibited the nocturnal hyperactivity, which was reversed by the combined infusion of m-CPP. The present study demonstrates that the 5-HT(2C) receptors in the hippocampus act to increase rat locomotor activity.

Aminopyridines↗
PubMed2001

Elevation of plasma free PAI-1 levels as an integrated endothelial response to severe burns.

To clarify the role of plasminogen activator inhibitor type 1 (PAI-1) in postburn hypercoagulation, we assayed the plasma levels of tissue-type plasminogen activator (t-PA) antigen, total PAI-1 antigen, and total t-PA-PAI-1 complex in 15 burned patients. The total body surface area of the burn injury ranged from 30 to 80%. Serial blood samples were collected from 12 to 168 h following the thermal injury. The plasma t-PA level and the free PAI-1 level increased significantly in the immediate postburn period, and the percent increase in the latter over the values in the healthy controls was much greater than that of the former. The ratio of the concentrations of t-PA-PAI-1 complex to free PAI-1 decreased throughout the 7 postburn days. The fact that the decreases in this ratio clearly showed no dissociation of the euglobulin fraction suggests that the postburn hypofibrinolysis occurred as a result of increased synthesis of PAI-1. On the other hand, changes in several parameters of the coagulation or fibrinolysis system and in plasma thrombomodulin showed that postburn hypercoagulability is associated with secondary hyperfibrinolysis with no evidence of vascular endothelial injury. The paradoxical coexistence of postburn hyper- and hypofibrinolysis is a good reflection of the character of PAI-1, which is a biphasic protein that is both a functional protein and an acute phase reactant. Thus, increased synthesis of PAI-1 may not enhance postburn hypercoagulability to create a coagulation-dominant type of disseminated intravascular coagulation severe enough to trigger multiple organ dysfunction syndrome. In conclusion, increased synthesis of PAI-1 in the initial postburn period reflects an integrated endothelial response to burn stress, and because it is a functional protein, the concentration of free PAI-1 antigen may be an important index for predicting secondary consumption coagulopathy.

Adult↗
PubMed2001

The differential effect of angiotensin II and angiotensin 1-7 on norepinephrine, epinephrine, and dopamine concentrations in rat hypothalamus: the involvement of angiotensin receptors.

Angiotensin 1-7 has been recently claimed the active member of the angiotensins' family. In the present study we compared the effect of angiotensin II and angiotensin 1-7 on the concentration of dopamine, serotonin, epinephrine, and norepinephrine and some of their metabolites in the rat hypothalamus, where the levels of angiotensins are particularly high. Intracerebroventricular injection of angiotensin II, but not angiotensin 1-7, time-dependently elevated the levels of both epinephrine (p < 0.05) and norepinephrine (p < 0.05) in the hypothalamus and both effects could be prevented by intracerebroventricular injection of either AT(1) (candesartan), AT(2) (PD123319) or AT(1-7) (A-779) receptor antagonist. Neither angiotensin II nor angiotensin 1-7 produced any changes in the level of dopamine, dihydroxyphenylacetic acid, homovanilic acid, serotonin, 5-hydroxyindoleacetic acid, or tryptophan at any time point in comparison with the control groups. However, AT(1) but not AT(2) receptor blockade, unmasked the stimulatory effect of angiotensin 1-7 on dopamine concentration in the hypothalamus. Thus, angiotensin II and its active metabolite angiotensin 1-7 regulate selectively, albeit differentially, adrenergic, noradrenergic and dopaminergic systems in the hypothalamus, the effects that involve AT(1), AT(2) and AT(1-7) angiotensin receptors.

3,4-Dihydroxyphenylacetic Acid↗
PubMed2001

Effects of combination psychotropic drug treatment on heart rate variability in psychiatric patients.

The aim of this study was to evaluate the effects of combination psychotropic drug treatment on heart rate variability (HRV), which was mainly controlled by the parasympathetic nervous system. Mean R-R intervals (mRR) and coefficient of variation (CV), an index of HRV, were studied in 22 psychiatric patients and 21 age- and sex-matched healthy controls. Next, in the patient group focusing on both anticholinergic and antidopaminergic properties, combination psychotropic drug daily doses were converted into biperiden milligram equivalents (BPDeq) and chlorpromazine milligram equivalents (CPZeq), respectively. The relationship between mRR and CV and these equivalent dosages was examined. A significant reduction in both mRR (P < 0.05) and CV (P < 0.05) was found in the patient group. In addition, significant negative correlations were observed between the dose of BPDeq and mRR (P < 0.05), and between the dose of BPDeq and CV (P < 0.005). In contrast, no significant correlations were observed between the dose of CPZeq and either parameter. These findings suggest that the effects of combination psychotropic drug treatment on HRV are mainly due to their anticholinergic properties. Therefore, CV is a useful indicator to assess the parasympathetic activity of psychiatric patients under combination psychotropic drug treatment.

Adult↗
PubMed2001

Redistribution of pulmonary blood flow during hypoxic exercise.

Pulmonary blood flow (PBF) distribution was studied at rest and during exercise in rats acclimatized to chronic hypoxia (barometric pressure [PB] 370 Torr for 3 weeks, A rats) and non-acclimatized (NA) littermates. Both A and NA rats exercised in hypoxia (inspired O2 pressure [PIO2] approximately 70 Torr) or in normoxia (PlO2 approximately 145 Torr). PBF distribution was determined using fluorescent-labeled microspheres injected into the right atrium. The lungs were cut into 28 samples to determine relative scatter of specific PBF ([sample fluorescence intensity/sample dry weight)/(total lung fluorescence intensity/total lung dry weight]). Exercise produced redistribution of PBF both in NA and A rats, and this effect was larger in hypoxia than in normoxia, with minimal redistribution occurring during normoxic exercise in NA rats. The pattern of distribution varies considerably among individual animals. As a result of distribution, the previous high flow areas would be overperfused during hypoxic exercise in some rats. The results support the concept that hypoxic pulmonary vasoconstriction is not uniform and suggest that the combination of hypoxia and exercise may lead to overperfusion and capillary leak in some individuals.

Acclimatization↗
PubMed2001

Tissue-type plasminogen activator is involved in the process of neuronal death induced by oxygen-glucose deprivation in culture.

Effect of tissue-type plasminogen activator (tPA) on oxygen-glucose deprivation (OGD) was studied in cultured cortical neurons prepared from tPA gene knockout (tPA-KO) and wild-type (Wt) mice. Three hours of OGD induced 45% and 23% of neuronal death in Wt and tPA-KO mice, respectively. Neuronal death in tPA-KO mice was increased to 42% by additional tPA. Six hours of OGD induced 80% and 40% of neuronal death in Wt and tPA-KO mice, respectively, whereas the addition of tPA increased to 62% in tPA-KO mice. These results suggest that tPA is directly involved in the process of neuronal death induced by ischemia-mimic stress without involving vascular or circulatory components.

Animals↗
PubMed2001

Urokinase receptor and vascular endothelial growth factor are synergistically associated with the liver metastasis of colorectal cancer.

Considering recent findings that the urokinase plasminogen activation (PA) system is involved in invasion and vascular endothelial growth factor (VEGF) is involved in angiogenesis of colorectal cancer, we evaluated these factors in the liver metastasis of primary colorectal cancer. Cancer tissues from 71 colorectal cancer patients were assayed quantitatively for antigen levels of urokinase type plasminogen activator (uPA), uPA receptor (uPAR), and plasminogen activator inhibitor-1 and -2 (PAI-1, PAI-2), and were also assayed immunohistochemically for expression of VEGF protein. Among the PA system factors, both the levels of uPAR and PAI-1 were significantly higher in larger tumors than in smaller ones, and were also significantly higher in tumors that invaded subserosa, serosa or adjacent organs than in mucosal, submucosal tumors or in tumors that invaded the muscle layer. The uPAR levels were significantly higher in tumors with liver metastasis than in those without. VEGF overexpression was significantly more frequent in tumors with lymph node involvement or liver metastasis than in those without. Among the PA system factors, the uPAR levels were significantly higher in tumors with VEGF overexpression and a multivariate analysis revealed that high uPA level and VEGF overexpression were independent risk factors for liver metastasis. The combination of high uPAR level and overexpression of VEGF was associated with the worst prognosis in patients with colorectal cancer. These results suggest that uPAR and VEGF might contribute synergistically to the liver metastasis of colorectal cancer.

Colorectal Neoplasms↗
PubMed2001

Somatic alterations of the DPC4 and Madr2 genes in colorectal cancers and relationship to metastasis.

The DPC4 and Madr2 genes are located at 18q21, and the LOH on chromosome 18q21 has been shown to occur frequently in colorectal cancers. To investigate the role of these genes in advanced colorectal cancers, we analyzed 29 colorectal specimens for alterations in the DPC4 and Madr2 genes. Twelve (63.2%) of 19 informative primary colorectal cancers showed allelic loss of chromosome 18q21.3 marker. An alteration of the DPC4 gene sequence was identified in 6 (20.7%) of 29 colorectal carcinomas, and the distinct Madr2 gene mobility shifts were present in 3 (10.3%) cancers. Somatic mutations were identified in these tumors by sequencing analysis. DPC4 gene alterations of 4 cases were detected in Mad homology 2 domains. There was no significant correlation between the somatic alteration of Madr2 and clinicopathological findings. However, the frequency of DPC4 mutation was significantly higher in tumors associated with liver metastasis than in those without such metastasis. Our findings suggest that somatic alteration of the DPC4 gene may play a role in tumorigenesis and liver metastasis of human colorectal cancers.

Chi-Square Distribution↗
PubMed2000

Expression cloning of human globoside synthase cDNAs. Identification of beta 3Gal-T3 as UDP-N-acetylgalactosamine:globotriaosylceramide beta 1,3-N-acetylgalactosaminyltransferase.

By using a eukaryocytic cell expression cloning system, we have isolated cDNAs of the globoside synthase (beta1, 3-N-acetylgalactosaminyltransferase) gene. Mouse fibroblast L cells transfected with SV40 large T antigen and previously cloned Gb3/CD77 synthase cDNAs were co-transfected with a cDNA library prepared from mRNA from human kidney together with Forssman synthase cDNA, and Forssman antigen-positive cells were panned using an anti-Forssman monoclonal antibody. The isolated cDNAs contained a single open reading frame predicting a type II membrane protein with 351 amino acids. Surprisingly, the cDNA clones turned out to be identical with previously reported beta3Gal-T3, which had been cloned by sequence homology with other galactosyltransferases. Substrate specificity analysis with extracts from cDNA-transfected L cells confirmed that the gene product was actually beta1, 3-N-acetylgalactosaminyltransferase that specifically catalyzes the transfer of N-acetylgalactosamine onto globotriaosylceramide. Results of TLC immunostaining of neutral glycolipids from the cDNA-transfected cells also supported the identity of the newly synthesized component as globoside. The results show that glycosyltransferases apparently belonging to a single glycosyltransferase family do not necessarily catalyze reactions utilizing the same acceptor or even the same sugar donor. The globoside synthase gene was expressed in many tissues, such as heart, brain, testis, etc. We propose the designation beta3GalNAc-T1 for the cloned globoside synthase gene.

Amino Acid Sequence↗
PubMed2000

Importance of GlcUAbeta1-3GalNAc(4S,6S) in chondroitin sulfate E for t-PA- and u-PA-mediated Glu-plasminogen activation.

Chondroitin sulfate E (CSE) markedly enhanced plasminogen activation by tissue plasminogen activators (t-PAs) and urinary plasminogen activator (u-PA) in vitro; in the presence of 10 microg/ml of CSE, the potentiation factors of single chain of t-PA, two chain of t-PA and u-PA were 400, 140 and 130, respectively. Though the potentiation activity of CSE gradually decreased when it was depolymerized by chondroitinase ABC, the specific disaccharide from CSE still showed significant activity. Glycosaminoglycan (GAG) from sea cucumber, which possesses a very similar core structure to CSE, but has additional sulfated fucose branches exhibit very weak activity. These results suggested that the minimal structural requirement in CSE to enhance plasminogen activation by plasminogen activators is GlcUAbeta1-3GalNAc(4S,6S) and that additional branching sugars abolish the activity.

Animals↗
PubMed2000

Molecular basis for the p phenotype. Identification of distinct and multiple mutations in the alpha 1,4-galactosyltransferase gene in Swedish and Japanese individuals.

p phenotype individuals lack both P(k) (Gb3) and P (Gb4) glycolipid antigens of the P blood group system. To explore the molecular basis for this phenotype, DNA sequences of Gb3 synthase (alpha1, 4-galactosyltransferase; alpha1,4Gal-T) in six p phenotype individuals from Japan and Sweden were analyzed. A missense mutation P251L and a nonsense mutation W261stop in three and one Japanese indivuiduals, respectively, and missense mutations M183K and G187D in one each of two Swedish p individuals were found, indicating that p individuals from Japan and Sweden have distinct and multiple homozygous point mutations in the coding region. In the function analysis of the mutated alpha1,4Gal-Ts by the transfection of the expression vectors, P251L and M183K mutations showed complete loss of enzyme function, and W261stop and G187D mutations resulted in the marginal activity. BLAST analysis of homologous sequences of alpha1, 4Gal-T revealed that three residues, Met(183), Gly(187), and Pro(251), at which missense mutations were found, were highly conserved among all species examined, suggesting their importance for the function of alpha1,4Gal-T.

Amino Acid Sequence↗
PubMed2000

Relevance of tissue factor and tissue factor pathway inhibitor for hypercoagulable state in the lungs of patients with idiopathic pulmonary fibrosis.

We investigated the role of tissue factor (TF) and tissue factor pathway inhibitor (TFPI) in the lungs of patients with idiopathic pulmonary fibrosis (IPF). Bronchoalveolar lavage (BAL) fluid was obtained from 22 patients with IPF, and the levels of TF and TFPI antigen were measured by ELISA. The TF and TFPI levels in BAL fluid supernatant were significantly higher in IPF patients than in normal controls. In addition, both levels were significantly higher in advanced cases than in nonadvanced cases. There was a significant correlation between the TF and TFPI levels. Localization of TF and TFPI antigens was investigated by immunohistochemical staining. Both antigens were mainly localized in hyperplastic cuboidal epithelial cells, suggesting that the widespread distribution of these cells contributed to the increase of TF and TFPI antigen levels in the lungs of IPF patients. To assess whether TF activity is counterbalanced by TFPI in the lungs of IPF patients, we examined procoagulant activity and TF activity. It was found, however, that both procoagulant and TF activities were significantly higher in the BAL fluid supernatant of IPF patients than in that of normal controls, which suggested that TFPI was actually increased, but the increase was insufficient to counterbalance TF, leading to the development of a hypercoagulable state in the lungs of IPF patients.

Adult↗
PubMed2000

Previous exposure to footshock stress attenuates nicotine-induced serotonin release in rat striatum during the subsequent stress.

We have analyzed the effects of chronic or repeated footshock stress on the release of serotonin (5-hydroxytryptamine: 5-HT) in the striatum of rats that received nicotine by using a microdialysis technique. Neither local infusion of nicotine alone nor stress application alone changed 5-HT release. Local infusion of 1 mM nicotine to the striatum, however, significantly increased 5-HT release in the striatum to 145.9 +/- 30.8 pg/dialysate during simultaneous stress application. These increases of extracellular 5-HT release induced by the combination of nicotine and stress application were also observed in rats that had received daily chronic footshock. However, the previously administered footshock induced the reduced release of 5-HT from the striatum to 33.5 +/- 8. 6 (repeated footshock) and 10.0 +/- 3.6 pg/dialysate (daily footshock) when footshock was given together with nicotine infusion. These results suggest that previous exposure to stress attenuated the nicotine-induced 5-HT release in the striatum during the subsequent stress.

Animals↗
PubMed2000

Serotonergic neurons projecting to hippocampus activate locomotion.

Although the role of brain serotonergic neurons in locomotion has been extensively studied, their influence may vary depending upon the terminal areas. Thus, using microdialysis and microinjection techniques, we examined the relationship between serotonin (5-HT) levels in striatum, hippocampus or prefrontal cortex (PFC) and motor activity in rats. The systemic injection (10 mg/kg i.p.) of monoamine oxidase inhibitor, tranylcypromine (TC), significantly elevated 5-HT levels in the striatum, hippocampus and PFC accompanied by a parallel increase in motor activity of the rats. This effect was mimicked by microinfusions of TC (1.0 mM) or 5-HT (1. 0 mM) into the hippocampus and to some extent into PFC (the response delayed in time), but not into striatum. The increase in motor activity produced by local infusions of TC either into the hippocampus or PFC could be prevented by pretreatment with 10 microM tetrodotoxin infused into the hippocampus. However, tetrodotoxin infused to PFC failed to prevent hyperlocomotion produced by intrahippocampal infusion of TC, although the response was delayed in time. Thus, we conclude that serotonergic neurons projecting to the hippocampus are involved in locomotor activity and PFC serotonergic fibers may facilitate hippocampal control of locomotion.

Animals↗