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Y Kaneda

Publications and source records attributed to Y Kaneda.

At least 91 records · Page 5Linked to original sources
PubMed2001

An essential role of the antioxidant gene Bcl-2 in myocardial adaptation to ischemia: an insight with antisense Bcl-2 therapy.

Reperfusion of ischemic myocardium results in apoptotic cell death, which can be blocked by adapting the heart to ischemic stress induced by cyclic episodes of brief periods of ischemia and reperfusion. In concert, the antiapoptotic gene bcl-2 is decreased by ischemia/reperfusion, but increased in the ischemically adapted myocardium. To examine if bcl-2 plays a crucial role in cardioprotection, adaptive cardioprotection was further examined in the hearts treated with antisense bcl-2 oligodeoxynucleotides (ODN). Isolated Langendorff-perfused rat hearts were divided into three groups: control (perfused with Krebs-Henseleit bicarbonate buffer for 210 min); 30-min ischemia followed by 2-h reperfusion; ischemic adaptation followed by 30-min ischemia and 2-h reperfusion. The last (adapted heart) group was subdivided into another two groups: one was transfected 48 h earlier with antisense bcl-2 ODN, whereas the other group was transfected with sense bcl-2 ODN. Cardioprotection was examined by determining cardiomyocyte death due to necrosis and apoptosis. Antisense gene therapy almost completely abolished bcl-2 protein expression in the hearts. Bcl-2 mRNA was down-regulated in the ischemic/reperfused heart, but up-regulated in the adapted myocardium. Adapted myocardium showed decreased infarct size and reduced number of apoptotic cardiomyocytes. Ischemia/reperfusion resulted in increased oxidative stress as evidenced by increased malonaldehyde formation. Adapted myocardium had a reduced amount of malonaldehyde. Antisense bcl-2 ODN completely abolished the cardioprotective effects of adaptation by eliminating the antideath signal of bcl-2. In concert, reduced oxidative stress in the adapted myocardium no longer persisted. The results suggest an antioxidant role of bcl-2 that appeared to be essential for the cardioprotection achieved by ischemic adaptation.

Adaptation, Physiological↗
PubMed2001

Efficient transfer of intact oligonucleotides into the nucleus of ligament scar fibroblasts by HVJ-cationic liposomes is correlated with effective antisense gene inhibition.

The efficacy of two different cationic liposomes, Lipofectin and hemagglutinating virus of Japan (HVJ)-cationic liposomes, on nuclear uptake of fluorescence-labeled phosphorothioate oligodeoxyribonucleotide (S-ODN) by ligament scar fibroblasts and suppression of decorin mRNA expression when antisense decorin S-ODN was transferred was investigated. There was no significant difference in nuclear uptake of fluorescent ODN between the two methods. However, only HVJ-cationic liposomes had a significant effect on suppression of decorin mRNA expression levels. To address the discrepancy, the molecular integrity of the transferred ODN in the cells was assessed by analysis of fluorescence resonance energy transfer (FRET) within double-fluorescence-labeled S-ODN. More than 70% of the ODN transfected by HVJ-cationic liposomes remained intact within the nucleus at 20 h after transfection, while the majority of the ODN transferred by Lipofectin was degraded at this point. These results suggest a strong relationship between the nuclear integrity of transfected antisense ODN and its suppression of target mRNA expression.

Active Transport, Cell Nucleus↗
PubMed2001

Decoy oligodeoxynucleotides as novel cardiovascular drugs for cardiovascular disease.

Gene therapy is emerging as a potential strategy in the treatment of cardiovascular disease such as restenosis after angioplasty, vascular bypass graft occlusion, and transplant coronary vasculopathy, for which no known effective therapy exists. One strategy for combatting disease processes is to target the transcriptional process. Application of DNA technology such as antisense strategy to regulate the transcription of disease-related genes in vivo has important therapeutic potential. Recently, transfection of cis-element double-stranded oligodeoxynucleotides (= decoy) as a powerful tool in a new class of antigene strategies for gene therapy was reported. Transfection of double-stranded oligodeoxynucleotides corresponding to cis sequence will result in the attenuation of authentic cis-trans interaction, leading to the removal of transfactors from the endogenous cis-elements with subsequent modulation of gene expression. This "decoy" strategy is not only a novel strategy for gene therapy as an antigene strategy, but also a powerful tool for the study of endogenous gene regulation in vivo as well as in vitro. In this review, we focus on the future potential of decoy oligodeoxynucleotide-based gene therapy in the treatment of cardiovascular disease.

Cardiovascular Agents↗
PubMed2001

Inhibition of TNF-alpha, induced cytokine and adhesion molecule. Expression in glomerular cells in vitro and in vivo by transcription factor decoy for NFkappaB.

Activation of certain cytokines and adhesion molecules has been postulated being involved in the pathogenesis of experimental and human glomerulonephritis. In this study, we examined whether the transcription factor, nuclear factor kappaB (NFkappaB), mediated the expression of these genes involved with the inflammatory response of mesangial cells by using transcription factor decoy oligodeoxynucleotides (ODN) to block NFkappaB binding to the promoter site of its target genes. We hypothesized that the NFkappaB decoy ODN can inhibit the coordinated activation of cytokines and adhesion molecules induced by TNF-alpha. Increased binding activity of NFkappaB induced by TNF-alpha was effectively blocked by the NFkappaB decoy ODN. TNF-alpha stimulated CAT expression, which was significantly inhibited by transfection of NFkappaB, but not by scrambled decoy ODN. Of importance, NFkappaB, but not scrambled decoy ODN, significantly attenuated the increase in RNA and protein levels of IL-1alpha, IL-1beta, IL-6, ICAM-1 and VCAM-1 induced by TNF-alpha assessed by RT-PCR. Moreover, in vivo transfection of NFkappaB decoy ODN inhibited expressions of these cytokines and adhesion molecules induced by TNF-alpha injection. These results suggest a novel therapeutic strategy for the treatment of glomerulonephritis using decoy ODN to block the binding of NFkappaB, inhibiting the coordinated transactivation of the key cytokines and adhesion molecules, and thereby suppressing the inflammatory process.

Animals↗
PubMed2001

Mitogenic and antiapoptotic actions of hepatocyte growth factor through ERK, STAT3, and AKT in endothelial cells.

Hepatocyte growth factor (HGF), a member of the angiogenic growth factors, may play a pivotal role in the regulation of endothelial cells, inasmuch as HGF shows mitogenic and antiapoptotic actions in endothelial cells. Because the mechanism of these actions is still unclear, we examined the signal transduction system of HGF in human aortic endothelial cells. Treatment of endothelial cells with recombinant HGF (rHGF) resulted in a significant increase in DNA synthesis as assessed by thymidine incorporation. Importantly, phosphorylation of extracellular signal-related kinase (ERK) and Akt by rHGF was clearly observed. Thus, we further examined the effects of specific inhibitors of ERK or Akt on cell proliferation. Pretreatment with PD98059, a mitogen-activated protein kinase kinase inhibitor, significantly attenuated cell proliferation induced by rHGF, whereas inhibitors of phosphatidylinositol-3-OH kinase, wortmannin, and LY-294002, did not. Interestingly, treatment with rHGF significantly increased the phosphorylation of the signal transducers and activators of transcription (STAT)3 (Ser727), whereas PD98059 attenuated the phosphorylation of Ser727 induced by rHGF. In addition, treatment with rHGF significantly increased the promoter activity of c-fos, which includes the sis-inducible element and serum response element, whereas PD98059 completely attenuated the activation of the c-fos promoter induced by rHGF. In contrast, inhibition of Akt by wortmannin and LY-294002 failed to inhibit the phosphorylation of STAT3 and c-fos activation. On the other hand, treatment with rHGF attenuated the increase in LDH release and caspase-3 activity induced by tumor necrosis factor-alpha stimulation. In contrast to DNA synthesis, wortmannin and LY-294002 markedly attenuated the decrease in caspase-3 activity mediated by rHGF, whereas PD98059 did not. Overall, the present study demonstrated that HGF stimulated cell proliferation through the ERK-STAT3 (Ser727) pathway and had an antiapoptotic action through the phosphatidylinositol-3-OH kinase-Akt pathway in human aortic endothelial cells. These findings provide new perspectives in the role of HGF in cardiovascular disease.

Androstadienes↗
PubMed2001

Contribution of Bcl-2, but not Bcl-xL and Bax, to antiapoptotic actions of hepatocyte growth factor in hypoxia-conditioned human endothelial cells.

Angiogenic growth factors play important roles in angiogenic responses, such as vasculogenesis and angiogenesis in response to hypoxia. A novel angiogenic growth factor, hepatocyte growth factor (HGF), has been reported to inhibit endothelial cell death. However, its molecular mechanisms are largely unknown. Thus, we studied (1) the effects of HGF on hypoxia-induced endothelial apoptosis and (2) the molecular mechanisms of the antiapoptotic actions of HGF in endothelial cells. Severe hypoxia increased the cell death rate in human aortic endothelial cells, whereas HGF significantly attenuated cell death. In addition, hypoxic treatment resulted in a significant increase in apoptotic cells, whereas HGF could attenuate apoptosis, accompanied by attenuation of the increase in caspase-3-like activity (P<0.01). Of importance, HGF significantly increased Bcl-2, an inhibitor of apoptosis, in a dose-dependent manner under normoxic and hypoxic conditions (P<0.01), whereas hypoxic conditions resulted in a significant decrease in Bcl-2. In contrast, HGF failed to affect Bcl-xL, which is also well known as an inhibitor of apoptosis under both normoxic and hypoxic conditions, whereas Bcl-xL was significantly decreased in endothelial cells exposed to hypoxia (P<0.01). No significant change in Bax, a promoter of apoptosis, was also observed in endothelial cells under hypoxia, whereas HGF did not affect BAX: Overall, this study demonstrated that HGF prevented endothelial cell death induced by hypoxia through its antiapoptotic action. The antiapoptotic mechanisms of HGF in hypoxia-induced endothelial cell death largely depend on Bcl-2, but not Bcl-xL and BAX:

Apoptosis↗
PubMed2001

Endothelial apoptosis induced by oxidative stress through activation of NF-kappaB: antiapoptotic effect of antioxidant agents on endothelial cells.

Injury of endothelial cells has been assumed to be an initial trigger of the development of atherosclerosis. In this study, we investigated the molecular mechanisms of endothelial cell death induced by hypoxia, which leads to oxidative stress. To study the relation between hypoxia-induced cell death and activation of nuclear factor-kappaB (NF-kappaB) in a hypoxic state, we evaluated the effect of 2 antioxidant drugs, probucol and pyrrolidine dithiocarbamate (PDTC), on human endothelial apoptosis. Although hypoxic treatment of human aortic endothelial cells resulted in a significant decrease in cell number and a significant increase in apoptotic cells compared with that of cells under normoxia (P<0.01), treatment with probucol (50 micromol/L) or PDTC (100 micromol/L) significantly attenuated the decrease in cell number (P<0.01) and was accompanied by inhibition of NF-kappaB activation. Furthermore, downregulation of bcl-2 caused by hypoxia was inhibited by these drugs. We further investigated the translocation of bax protein from the cytoplasm to the mitochondrial heavy fraction membrane, as translocation of bax protein is considered to be a determinant of apoptosis. Interestingly, we found that antioxidant treatment inhibited the translocation of bax protein caused by hypoxia. Moreover, upregulation of p53, a proapoptotic molecule, was observed in hypoxia, whereas treatment with probucol attenuated the expression of p53 accompanied by suppression of NF-kappaB activation. These data suggest functional links between p53 and endothelial apoptosis through the activation of NF-kappaB. Overall, the current study demonstrated that oxidative stress induced apoptosis in human aortic endothelial cells through the downregulation of bcl-2, translocation of bax, and upregulation of p53, probably through NF-kappaB activation. Oxidative stress may play an important role in endothelial apoptosis mediated by hypoxia, through the activation of NF-kappaB.

Anticholesteremic Agents↗
PubMed2001

Hepatocyte growth factor ameliorates acute graft-versus-host disease and promotes hematopoietic function.

Acute graft-versus-host disease (GVHD) is a major complication of bone marrow transplantation (BMT) and is characterized by hematopoietic dysfunction, immunosuppression, and tissue injury in the skin, liver, and intestinal mucosa. Hepatocyte growth factor (HGF), originally identified and cloned as a potent mitogen for hepatocytes, induces mitogenic and antiapoptotic activity in various epithelial cells and promotes hematopoiesis. Working in a murine model of acute GVHD, we performed repeated transfection of the human HGF cDNA into skeletal muscle and showed that this treatment inhibited apoptosis of intestinal epithelial cells and donor T-cell infiltration into the liver, thereby ameliorating the enteropathy and liver injury caused by acute GVHD. HGF also markedly suppressed IFN-gamma and TNF-alpha expression in the intestine and liver and decreased the serum IL-12. Furthermore, extramedullary hematopoiesis by donor cells was increased, and the survival rate was improved. These results suggest that HGF may be useful for controlling acute GVHD after allogeneic BMT.

Animals↗
PubMed2001

[Gene therapy: current status and promise].

As of summer 2000, more than 400 protocols developed for human gene therapy have been reported, and there have been recent successful applications in some diseases such as arteriosclerosis obliterance, immunodeficiency X-1 (SCID-X1) and hemophilia B. However, complications have also occurred. Successful gene therapy is dependent on the development of an effective gene delivery system. One approach is development of chimeric vector systems that combine at least two different vector systems. However, a perfect vector system has not yet been constructed. Difficulties of in vivo gene transfer appear to result from resistance of living cells to invasion by foreign materials and from interference of cellular functions. We should reevaluate what barriers in tissues affect in vivo gene transfection and how to solve these problems for gene therapy. Moreover, in Japan, there should be more extensive preparation of social systems to promote clinical trials based on basic research.

Animals↗
PubMed2001

Effects of risperidone on gonadal axis hormones in schizophrenia.

OBJECTIVE: To investigate the effects of risperidone on the hypothalamo-pituitary-gonadal (HPG) axis of chronic schizophrenic male inpatients medicated regularly. METHODS: Subjects included six inpatients who were diagnosed according to the Diagnostic and Statistical Manual, Fourth Edition, criteria for schizophrenia, and were termed treatment-refractory. Each patient gave informed consent for the research involved in this study. The neuroendocrine studies were done before and during risperidone administration. Patients took a mean dose of risperidone 9.5 mg/d for a mean period of 64.2 days. Psychotic symptoms were assessed using the Brief Psychiatric Rating Scale (BPRS). RESULTS: Prolactin (PRL) increased significantly during risperidone administration. However, luteinizing hormone, follicle-stimulating hormone, and testosterone did not show significant difference between blood concentrations before and during risperidone administration. Scores of the BPRS total, thought disturbance factor, and tension decreased significantly during risperidone administration. Throughout the study, none of the patients experienced clinically significant problems associated with elevated PRL concentrations including gynecomastia and/or sexual dysfunction. CONCLUSIONS: Addition of risperidone produced significant improvement of psychotic symptoms in treatment-resistant schizophrenic patients, and an increase in basal blood PRL concentrations, but not in basal blood HPG axis hormone concentrations. This preliminary result warrants further double-blind evaluation with a larger sample.

Antipsychotic Agents↗
PubMed2001

Reconstitution of chromatin in vitro.

It is now generally believed that DNA methylation is responsible for genomic imprinting in mammals (1). Recent experimental evidence has provided an elegant mechanism for repression of gene expression by DNA methylation. This evidence suggests that proteins that recognize specifically methylated CpGs may contribute to the formation of inactive chromatin (2-5). Nucleosomes are the basic unit of chromatin, consisting of a core of 146 bp of DNA wrapped around a histone octamer (two molecules of each of H2A, H2B, H3, and H4) and a stretch of linker DNA between adjacent nucleosomes. The binding of a fifth histone, known as a linker histone or H1, promotes the packaging of strings of nucleosomes into a 30 nm chromatin fiber (6). Packaging of DNA into nucleosomes and the chromatin fiber greatly restricts the availability of the DNA for nuclear processes such as transcription.

Chromatin↗
PubMed2001

Gene therapy: a battle against biological barriers.

One factor critical to successful human gene therapy is development of efficient gene delivery systems. Although numerous vector systems for gene transfer have been developed, a perfect vector system has not yet been constructed. Difficulties of in vivo gene transfer appear to result from resistance of living cells to invasion by foreign materials and from interference of cellular functions. We should analyze what barriers in tissues affect in vivo gene transfection and how to solve these problems for gene therapy. In this review article, the biological barriers to in vivo gene transfection are discussed and possible solutions to each barrier are discussed with respect to construction of a perfect gene therapy vector system.

Cell Nucleus↗
PubMed2001

Phosphorylation of p38 mitogen-activated protein kinase downstream of bax-caspase-3 pathway leads to cell death induced by high D-glucose in human endothelial cells.

Because high D-glucose significantly stimulates endothelial cell death, we examined the molecular mechanisms of high D-glucose-induced endothelial apoptosis. Treatment of human aortic endothelial cells with high D-glucose (25 mmol/l), but not mannitol and L-glucose, resulted in a significant decrease in cell number and a significant increase in apoptotic cells as compared with a physiological concentration (5 mmol/l). Interestingly, high D-glucose treatment significantly increased bax protein, accompanied by translocation of bax protein from cytosol to mitochondria-enriched heavy membrane fraction. In contrast, the expression and distribution of bcl-2 protein were not altered by high D-glucose. In addition, the activity of caspase-3 proteases was increased after exposure to high glucose, whereas caspase inhibitors prevented endothelial cell death induced by high D-glucose. On the other hand, p38 mitogen-activated protein kinase (MAPK) was markedly phosphorylated and showed sustained phosphorylation after stimulation. A specific inhibitor of p38 MAPK, SB 203580, and the overexpression of kinase-inactive p38 MAPK significantly attenuated cell death induced by high D-glucose in human aortic endothelial cells, whereas at 6 h after high D-glucose treatment, SB 203580 and overexpression of kinase-inactive p38 MAPK did not attenuate caspase-3 activation induced by high D-glucose. Importantly, caspase inhibitors significantly attenuated the sustained phosphorylation of p38 MAPK induced by high D-glucose. Thus, we finally focused the MAPK kinase (MEK) kinase 1 (MEKK1) to further examine the cross-talk between p38 MAPK and the bax-caspase proteases pathway. High D-glucose treatment induced MEKK1 cleavage, whereas caspase inhibitors significantly attenuated the cleavage. Importantly, kinase-inactive MEKK1 also blocked the phosphorylation of p38 MAPK induced by high D-glucose. Here, we demonstrated that high D-glucose induced apoptosis in human endothelial cells through activation of the bax-caspase proteases pathway and through phosphorylation of p38 MAPK mediated by MEKK1. Phosphorylation of p38 MAPK downstream of the bax-caspase pathway may play a pivotal role in endothelial apoptosis mediated by high D-glucose.

Animals↗
PubMed2001

Mild serotonin syndrome on fluvoxamine.

OBJECTIVE: This preliminary study was performed to investigate the prevalence and severity of the serotonin-related symptoms for a group of patients in a clinical setting during fluvoxamine (FLU) using the Japanese version of the Serotonin Syndrome Scale (JSSS). METHODS: The subjects for the present study were 37 patients (20 and 17 patients with mood and anxiety disorders, respectively), meeting a diagnosis of DSM-IV. Each subject gave informed consent for the research involved in this study. Presence and severity of the serotonin-related symptoms were determined by Sternbach's criteria and the JSSS, respectively. RESULTS: (1) At the time of assessment, none of the patients fulfilled the diagnostic criteria of SS proposed by Sternbach, or none of the total JSSS scores of the patients was sufficient to reach the cutoff point of 7. (2) Sixteen of the 37 patients (43.2%) showed at least one symptom in the JSSS. (3) Spearman's rank correlations showed that there was a positive but nonsignificant correlation between the total JSSS scores and dosages of FLU. CONCLUSION: This preliminary study suggested that milder forms of the serotonin syndrome may exist for a group of patients in a clinical setting during FLU therapy.

Adult↗
PubMed2001

Ribodemes of Blastocystis hominis isolated in Japan.

To determine if genetic diversity of Blastocystis hominis exists in Japan, we monitored 64 B. hominis-infected people: 39 asymptomatic people whose infections were detected during routine medical check-ups (32 Japanese and 7 non-Japanese) and 25 patients with gastrointestinal symptoms who visited the outpatient clinics of St. Luke's International Hospital (19 Japanese and 6 non-Japanese). We detected 6 known and 2 new riboprint patterns in isolates from the infected people. There were no differences in the distribution of ribodemes between isolates from Japanese and non-Japanese people, similar to that in other countries. However, we noted a possible relationship between ribodeme type and pathogenicity. The results suggest that ribodemes I, III, and VI may be responsible for gastrointestinal symptoms.

Animals↗
PubMed2001

Monitoring of chicken houses and an attached egg-processing facility in a laying farm for Salmonella contamination between 1994 and 1998.

Two chicken houses and an attached egg-processing facility in a laying farm were sampled between 1994 and 1998 to investigate Salmonella contamination. Each of the houses was environmentally controlled and fitted with egg belts that transported eggs from the houses to the egg-processing facility. Four hundred twenty-eight Salmonella isolates were obtained from 904 environmental samples collected from the houses. Two hundred fifty-two of the 428 (58.9%) isolates yielded five serotypes as follows: Salmonella enterica subsp. enterica serovar Livingstone, Salmonella serovar Cerro, Salmonella serovar Montevideo, Salmonella serovar Mbandaka, and Salmonella serovar Corvallis. The remaining (41.1%, 176 of 428) isolates included four other serotypes and isolates that were untypeable. Salmonella isolates obtained from the drain water collected after the washing of the eggs in the egg-processing facility yielded the same serotypes as those found in the chicken houses. Strains having an identical pulsed-field gel electrophoresis (PFGE) pattern were continually recovered from a house for more than 1 year. Several strains of Salmonella Cerro, Salmonella Mbandaka, and Salmonella Montevideo obtained from both the houses and from the egg-processing facility were indistinguishable by PFGE, respectively. These results suggest that Salmonella organisms originating from a single clone colonized the chicken houses and that the egg belts are likely to be one of the means by which Salmonella organisms are spread from one house to the others.

Animal Husbandry↗
PubMed2001

[Assessment of stage IIB lung cancer from the pathological factors].

In our experience, the prognosis of patients with pathological T3N0M0 lung cancer is generally poor, the 5-year survival rate being almost the same as that of patients with stage IIIA disease. Thus, we assessed patients with stage IIB disease by examining the pathological factors, lymphatic invasion, vessel invasion, histological type, differentiation, tumor size, and node dissection. Lymphatic invasion was found to be positive in 20 of 21 cases, patients with T3N0M0 lung cancer, and all of those with positive vessel invasion had a significantly poor prognosis. This indicates that positive lymphatic and vessel invasion could be a prognostic factor predicting a poor outcome. Patients with T3N0M0 lung cancer that are found to have this poor prognostic factor may not be diagnosed as having stage IIB disease.

Aged↗