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Biomedical subjects

Junji Yodoi

Publications and source records attributed to Junji Yodoi.

At least 55 records · Page 3Linked to original sources

Increased plasma levels of thioredoxin in patients with glucose intolerance.

OBJECTIVE: The aim of the present study was to determine the effects of glucose intolerance on oxidative stress in patients with coronary artery disease (CAD). METHODS: The patients were divided into 3 groups, diabetes mellitus (DM), IGT or normal glucose tolerance (NGT) according to the criteria of the American Diabetes Association. PATIENTS: The present study consisted of 178 consecutive patients who underwent diagnostic coronary arteriography and a 75-g glucose tolerance test. RESULTS: The level of plasma thioredoxin, a marker of oxidative stress was measured in every patient during the fasting state. The levels of plasma thioredoxin were significantly higher in the DM and IGT groups than the NGT group. Furthermore, we found that there was a positive association between thioredoxin levels and glycosylated hemoglobin (sigma=0.225, p=0.018). In multivariate logistic regression analysis, glucose intolerance (DM or IGT) was only independently associated with the high levels of thioredoxin. The levels of plasma thioredoxin were significantly higher in the CAD group compared to the non-CAD group. In multivariate logistic regression analysis, high levels of thioredoxin, male, age and hypertension were independently associated with the presence of CAD. CONCLUSION: Glucose intolerance was associated with the high levels of thioredoxin. High levels of thioredoxin were related to the presence of CAD. The measurement of thioredoxin as the marker of oxidative stress may be useful for monitoring the development of the cardiovascular diseases.

Adult↗

Expression of thioredoxin in patients with Graves' disease.

Thioredoxin (TRX), which is a stress-inducible protein with redox-active disulfide structures, has various biological activities by regulating DNA binding of transcription factors in cells. In Graves' disease that is among the common diseases of the thyroid, endogenous stresses that are induced by excess thyroid hormones or antibodies against thyroid stimulating hormone (TSH) receptors are responsible for the pathogenesis. The objective of this study was to examine the expression of TRX and to determine whether TRX is responsible for the pathogenesis of Graves' disease. The thyroid follicular cells were shown to express both TRX and vascular cell growth factors (VEGF) in all of the patients with Graves' disease by immunohistochemistry. In contrast, the expression of TRX or VEGF was not found in any of the normal thyroids. Serum levels of TRX were significantly elevated in patients with Graves' disease regardless of their thyroid function compared to those in healthy donors (122+/-16 versus 37+/-5 ng/ml, p<0.0001). Consecutive administration of iodine resulted in not only a reduction in serum levels of free triiodothyronine (T3) but also an increase in serum levels of TRX in the patients. These findings suggest that release of intracellular TRX from thyroid follicular cells in response to iodine resulted in suppression of T3 production. Taken together, TRX is highly produced under stress in Graves' disease and involved in regulating production of thyroid hormones. The investigation of biological behavior of this molecule may greatly help to understand pathogenesis of Graves' disease functions.

Graves Disease↗

Regulation of human osteoclast differentiation by thioredoxin binding protein-2 and redox-sensitive signaling.

UNLABELLED: Differential expression of TBP-2 and Trx-1 occurs during osteoclastogenesis. Adenoviral overexpression of TBP-2 in osteoclast precursors inhibits Trx-1 expression, osteoclast formation, and AP-1 binding activity. TBP-2 and Trx-1 are key regulators of osteoclastogenesis. INTRODUCTION: Thioredoxin binding protein-2 (TBP-2) negatively regulates thioredoxin-1 (Trx-1), a key endogenous modulator of cellular redox and signaling. In gene array analysis, we found that TBP-2 expression was reduced during human osteoclast differentiation compared with macrophage differentiation. Our aim was to determine the roles of TBP-2 and Trx-1 in human osteoclastogenesis and RANKL signaling. MATERIALS AND METHODS: Osteoclasts or macrophages were generated from colony-forming unit-granulocyte macrophage (CFU-GM) precursors treated with sRANKL and macrophage-colony-stimulating factor (M-CSF), or M-CSF alone, respectively. Expression of TBP-2 and Trx-1 was quantified by real-time PCR and Western analysis. Adenoviral gene transfer was used to overexpress TBP-2 in precursors. NF-kappaB and activator protein 1 (AP-1) signaling was assessed with EMSA. RESULTS: In the presence of sRANKL, expression of TBP-2 was decreased, whereas Trx-1 expression was increased. The antioxidant N-acetylcysteine reversed this pattern and markedly inhibited osteoclastogenesis. Adenoviral overexpression of human TBP-2 in precursors inhibited osteoclastogenesis and Trx-1 expression, inhibited sRANKL-induced DNA binding of AP-1, but enhanced sRANKL-induced DNA binding of NF-kappaB. CONCLUSIONS: These data support significant roles for TBP-2 and the Trx system in osteoclast differentiation that are mediated by redox regulation of AP-1 transcription. A likely mechanism of stress signal induction of bone resorption is provided. Modulators of the Trx system such as antioxidants have potential as antiresorptive therapies.

Adenoviridae↗

Thioredoxin-1 ameliorates myosin-induced autoimmune myocarditis by suppressing chemokine expressions and leukocyte chemotaxis in mice.

BACKGROUND: Cardiac myosin-induced myocarditis is an experimental autoimmune myocarditis (EAM) model used to investigate autoimmunological mechanisms in inflammatory heart diseases and resembles fulminant myocarditis in humans. We investigated the therapeutic role of thioredoxin-1 (TRX-1), a redox-regulatory protein with antioxidant and antiinflammatory effects, in murine EAM. METHODS AND RESULTS: EAM was generated in 5-week-old male BALB/c mice by immunization with porcine cardiac myosin at days 0 and 7. Recombinant human TRX-1 (rhTRX-1), C32S/C35S mutant rhTRX-1, or saline was administered intraperitoneally every second day from day 0 to 20. In addition, rabbit anti-mouse TRX-1 serum or normal rabbit serum was administered intraperitoneally on days -1, 2, and 6. Animals were euthanized on day 21. Histological analysis of the heart showed that TRX-1 significantly reduced the severity of EAM, whereas mutant TRX-1 failed to have such an effect, and anti-TRX-1 antibody enhanced the disease markedly. Immunohistochemical analysis showed that TRX-1 significantly suppressed cardiac macrophage inflammatory protein (MIP)-1alpha, MIP-2, and 8-hydroxydeoxyguanosine expression and macrophage infiltration into the heart in EAM. Although serum levels of MIP-1alpha were not suppressed by TRX-1 until day 21, both an in vitro chemotaxis chamber assay and an in vivo air pouch model showed that TRX-1 significantly suppressed MIP-1alpha- or MIP-2-induced leukocyte chemotaxis. However, real-time reverse transcription-polymerase chain reaction showed that TRX-1 failed to decrease chemokine receptor expression increased in the bone marrow cells of EAM mice. CONCLUSIONS: TRX-1 attenuates EAM by suppressing chemokine expressions and leukocyte chemotaxis in mice.

Amino Acid Substitution↗

Cardioprotective effects of thioredoxin in myocardial ischemia and reperfusion: role of S-nitrosation [corrected].

Apoptosis contributes to myocardial ischemia/reperfusion (MI/R) injury, and both thioredoxin (Trx) and nitric oxide have been shown to exert antiapoptotic effects in vitro. Recent evidence suggests that this particular action of Trx requires S-nitrosation at Cys-69. The present study sought to investigate whether or not exogenously applied Trx reduces MI/R injury in vivo and to which extent this effect depends on S-nitrosation. Adult mice were subjected to 30 min of MI and treated with either vehicle or human Trx (hTrx, 2 mg/kg, i.p.) 10 min before reperfusion. Native hTrx was incorporated into myocardial tissue as shown by immunostaining, and reduced MI/R injury as evidenced by decreased terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL) staining, DNA fragmentation, caspase-3 activity, and infarct size. When hTrx was partially S-nitrosated by preincubation with S-nitrosoglutathione, its cardioprotective effect was markedly enhanced. Treatment with hTrx significantly reduced p38 mitogen-activated protein kinase (MAPK) activity, and this effect was also potentiated by S-nitrosation. To further address the role of S-nitrosation for the overall antiapoptotic effect to Trx, the action of Escherichia coli Trx (eTrx) was investigated in the same model. Whereas eTrx inhibited MI/R-induced apoptosis to a degree similar to hTrx, S-nitrosation of this protein, which lacks Cys-69, failed to further enhance its antiapoptotic action. Collectively, our results demonstrate that systemically applied Trx is taken up by the myocardium to exert potent cardioprotective effects in vivo, offering interesting therapeutic avenues. In the case of hTrx, these effects are further potentiated by S-nitrosation, but this posttranslational modification is not essential for protection.

Animals↗

Proteasome-dependent degradation of cyclin D1 in 1-methyl-4-phenylpyridinium ion (MPP+)-induced cell cycle arrest.

1-Methyl-4-phenylpyridinium ion (MPP(+)), an active metabolite of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, induces cell death and inhibition of cell proliferation in various cells. However, the mechanism whereby MPP(+) inhibits cell proliferation is still unclear. In this study, we found that MPP(+) suppressed the proliferation with accumulation in G(1) phase without inducing cell death in p53-deficient MG63 osteosarcoma cells. MPP(+) induced hypophosphorylation of retinoblastoma protein and rapidly down-regulated the protein but not mRNA levels of cyclin D1 in MG63 cells. The down-regulation of cyclin D1 protein was suppressed by a proteasome inhibitor, MG132. The cyclin D1 down-regulation by MPP(+) was also observed in p53-positive PC12, HeLa S3, and HeLa rho(0) cells, which are a subclone of HeLa S3 lacking mitochondrial DNA. Moreover, MPP(+) dephosphorylated Akt in PC12 cells, which was rescued by the pretreatment with nerve growth factor. In addition, the pretreatment with nerve growth factor or lithium chloride, a glycogen synthase kinase-3beta inhibitor, suppressed the cyclin D1 down-regulation caused by MPP(+). Our results demonstrate that MPP(+) induces cell cycle arrest independently of its mitochondrial toxicity or the p53 status of the target cells, but rather through the proteasome- and phosphatidylinositol 3-Akt-glycogen synthase kinase-3beta-dependent cyclin D1 degradation.

1-Methyl-4-phenylpyridinium↗

Importin alpha1 (Rch1) mediates nuclear translocation of thioredoxin-binding protein-2/vitamin D(3)-up-regulated protein 1.

Thioredoxin-binding protein-2 (TBP-2)/vitamin D(3) up-regulated protein 1 is an endogenous molecule interacting with thioredoxin (TRX), negatively regulating TRX function, and being implicated in the suppression of tumor development and metastasis. We found that TBP-2 ectopically expressed in the breast cancer cell line MCF-7 was localized predominantly in the nucleus exhibiting growth suppressive activity. The nuclear accumulation of endogenous TBP-2 protein was also demonstrated when the cells were treated with an anti-cancer drug, suberoylanilide hydroxamic acid. To investigate the mechanism underlying the nuclear localization, we performed a yeast two-hybrid screening and identified importin alpha(1) (Rch1) as a protein interacting with TBP-2. The physical interaction between TBP-2 and Rch1 was confirmed with a glutathione S-transferase pull-down assay. The interaction of TBP-2 was specific to Rch1 among other importin alpha subfamilies (Qip1 and NPI-1), and amino acids 1-227 of TBP-2 were sufficient for both the interaction with Rch1 and the nuclear localization, although there is no typical nuclear localization signal in this sequence. The expression of short interfering RNA of Rch1 suppressed suberoylanilide hydroxamic acid-induced nuclear accumulation of TBP-2. Collectively, our results strongly suggest that an interaction with importin system is required for TBP-2 nuclear translocation and growth control tightly associated with TRX-dependent redox regulation of transcription factors.

Animals↗

Cysteine-dependent immune regulation by TRX and MIF/GIF family proteins.

Thioredoxin (TRX) superfamily proteins that contain a conserved redox-active site -Cys-Xa.a.-Xa.a.-Cys- includes proinflammatory cytokine, macrophage migration inhibiting factor (MIF) and the immune regulatory cytokine, glycosylation inhibiting factor (GIF) in which Cys-60 is cysteinylated. In this report, we have analyzed the functional interaction between TRX and MIF/GIF. The stable Jurkat T cell line transfected with human TRX gene (TRX-transfectant) was highly resistant to hydrogen peroxide-induced apoptosis, but not the cell line transfected with vector (mock-transfectant). The expression level of MIF/GIF protein of TRX-transfectant was lower than that of mock-transfectant. Conversely, the expression level of intracellular TRX protein in CD4(+)-T cells derived from MIF -/- mice were significantly higher than that from background BALB/c mice. These findings collectively suggest that oxidative stress-induced apoptosis on T lymphocytes might be protected by the reciprocal regulation of TRX and MIF/GIF expression.

Animals↗

TMX, a human transmembrane oxidoreductase of the thioredoxin family: the possible role in disulfide-linked protein folding in the endoplasmic reticulum.

Various proteins sharing thioredoxin (Trx)-like active site sequences (Cys-Xxx-Xxx-Cys) have been found and classified in the Trx superfamily. Among them, transmembrane Trx-related protein (TMX) was recently identified as a novel protein possessing an atypical active site sequence, Cys-Pro-Ala-Cys. In the present study, we describe the properties of this membranous Trx-related molecule. Endogenous TMX was detected as a protein of approximately 30 kDa with a cleavable signal peptide. TMX was enriched in membrane fractions and exhibited a similar subcellular distribution with calnexin localized in the endoplasmic reticulum (ER). The examination of membrane topology of TMX suggested that the N-terminal region containing the Trx-like domain was present in the ER lumen, where protein disulfide isomerase (PDI) was found to assist protein folding. Recombinant TMX showed PDI-like activity to refold scrambled RNase. These results indicate the possibility that TMX can modify certain molecules with its oxidoreductase activity and be involved in the redox regulation in the ER.

Calnexin↗

Loss of thioredoxin-binding protein-2/vitamin D3 up-regulated protein 1 in human T-cell leukemia virus type I-dependent T-cell transformation: implications for adult T-cell leukemia leukemogenesis.

Human T-cell leukemia virus type I (HTLV-I) is the causative agent of adult T-cell leukemia (ATL). However, the low incidence of ATL among HTLV-I-infected carriers, together with a long latent period, suggests that multiple host-viral events are involved in the progression of HTLV-I-dependent transformation and subsequent development of ATL. Human thioredoxin (TRX) is a redox active protein highly expressed in HTLV-I-transformed cell lines, whereas the TRX-binding protein-2/vitamin D3 up-regulated protein 1 (TBP-2/VDUP1) was recently identified as a negative regulator of TRX. We report here that expression of TBP-2 is lost in HTLV-I-positive, interleukin-2-independent T-cell lines but maintained in HTLV-I-positive, interleukin-2-dependent T-cell lines, as well as HTLV-I-negative T-cell lines. Ectopic overexpression of TBP-2 in HTLV-I-positive T cells resulted in growth suppression. In the TBP-2-overexpressing cells, a G1 arrest was observed in association with an increase of p16 expression and reduction of retinoblastoma phosphorylation. The results suggest that TBP-2 plays a crucial role in the growth regulation of T cells and that the loss of TBP-2 expression in HTLV-I-infected T cells is one of the key events involved in the multistep progression of ATL leukemogenesis.

Carrier Proteins↗

Redox-sensing release of human thioredoxin from T lymphocytes with negative feedback loops.

Thioredoxin (TRX) is released from various types of mammalian cells despite no typical secretory signal sequence. We show here that a redox-active site in TRX is essential for its release from T lymphocytes in response to H2O2 and extracellular TRX regulates its own H2O2-induced release. Human T cell leukemia virus type I-transformed T lymphocytes constitutively release a large amount of TRX. The level of TRX release is augmented upon the addition of H2O2, but suppressed upon the addition of N-acetylcysteine. In the culture supernatant of a Jurkat transfectant expressing the tagged TRX-wild type (WT), the tagged TRX protein is rapidly released at 1 h and kept at a constant level until 6 h after the addition of H2O2. In contrast, another type of transfectant expressing the tagged TRX mutant (C32S/C35S; CS) fails to release the protein. H2O2-induced release of TRX from the transfectant is inhibited by the presence of rTRX-WT in a dose-dependent manner. Preincubation of the transfectant with rTRX-WT for 1 h at 37 degrees C, but not 0 degrees C, results in a significant suppression of the TRX release, reactive oxygen species, and caspase-3 activity induced by H2O2, respectively. Confocal microscopy and Western blot analysis show that extracellular rTRX-WT added to the culture does not obviously enter T lymphocytes until 24 h. These results collectively suggest that the oxidative stress-induced TRX release from T lymphocytes depends on a redox-sensitive event and may be regulated by negative feedback loops using reactive oxygen species-mediated signal transductions.

Apoptosis↗

Thioredoxin, a redox-regulating protein, is expressed in spontaneous myocarditis in inbred strains of mice.

Redox-regulating mechanisms may be involved in the pathogenesis of aging. Thioredoxin (TRX) is a small multifunctional protein which contains a redox active sequence. Spontaneous myocarditis is often observed in aged mice. In this study, we examined the histopathology and characteristics of TRX expression in spontaneous myocarditis in inbred strains of mice. No spontaneous myocarditis was found in adult 4-week-old inbred strains of mice. High incidence of spontaneous myocarditis was found in aged 8-week-old DBA/2 mice, and low incidence was in 8-week-old BALB/c or C57BL/6 mice. The lesions, limited to the right ventricle, were most severe in DBA/2 mice. TRX was upregulated, and the expression was correlated with the severity of the disease in these strains. Also, 8-hydroxy-2'-deoxyguanosine (8-OHdG), which was an established marker for oxidative stress, was concomitantly positive in necrotic lesions among them. In addition, the long-term anti-oxidant treatment with N-acetylcysteine (NAC) suppressed the development of spontaneous myocarditis. Thus, TRX may be induced by the spontaneously developed myocarditis, and the redox-regulating system may play an important role in the development of aging-related myocarditis.

Acetylcysteine↗

Vitamin E improves fibrinolytic activity in patients with coronary spastic angina.

INTRODUCTION: The fibrinolytic system has a major role as a defense mechanism against thrombus formation. Net fibrinolytic activity in plasma reflects the balance between tissue-type plasminogen activator and plasminogen activator inhibitor (PAI). PAI is the main factor determining overall fibrinolytic activity. MATERIALS AND METHODS: We examined the effects of oral administration of vitamin E, an antioxidant, on fibrinolytic activity and oxidative stress in patients with coronary spastic angina. Forty patients with coronary spastic angina were randomly assigned into two treatment groups, either vitamin E group (alpha-tocopherol acetate, 400 mg/day) or placebo group by means of computerized system. PAI activity and thioredoxin, a marker of oxidative stress, levels were measured before and at the end of 1 month treatment. RESULTS: Before treatment, the levels of PAI activity and thioredoxin were increased in patients with coronary spastic angina as compared with control subjects (n=17) (PAI activity levels: 13.6+/-1.4 vs. 7.6+/-2.2 IU/ml, p<0.05, thioredoxin levels: 22.8+/-1.7 vs. 16.0+/-1.4 ng/ml, p<0.05). In patients with coronary spastic angina, administration of vitamin E decreased both PAI activity and thioredoxin levels (PAI activity levels: 14.7+/-1.7 to 7.5+/-1.6 IU/ml, p<0.01, thioredoxin levels: 23.3+/-2.4 to 15.1+/-2.5 ng/ml, p<0.01), whereas placebo had no effect on these variables. CONCLUSIONS: Oral administration of vitamin E improved fibrinolytic activity and the improvement was associated with a decrease in oxidative stress. Administration of vitamin E is possible to be an effective adjunct therapy of coronary spasm in the absence of coronary atherosclerosis.

Administration, Oral↗

Increased plasma levels of thioredoxin in patients with coronary spastic angina.

To determine whether plasma levels of thioredoxin are associated with coronary spasm, we measured the plasma levels of thioredoxin in 170 patients who had <25% organic stenosis in coronary arteriography. According to the results of cardiac catheterization, we divided the patients into two groups: a coronary spastic angina group (n=84) and a chest pain syndrome group (n=86). The plasma levels of thioredoxin were significantly higher in the coronary spastic angina group than in the chest pain syndrome group (40.7 +/- 4.1 versus 18.2 +/- 1.1 ng/ml, p<0.0001). Furthermore, the increased plasma levels of thioredoxin were associated with high disease activity indicated by the frequency of angina attacks (p=0.0004). In multiple logistic regression analysis, the higher levels of thioredoxin [relative risk 14.8, 95% confidence interval (5.13-42.9), p<0.0001] and current smoking [relative risk 3.39, 95% confidence interval (1.31-8.75), p=0.012] were significant and independent variables associated with coronary spasm. We demonstrated that the plasma levels of thioredoxin were increased in the coronary spastic angina group, and increased levels of thioredoxin were associated with high disease activity. The plasma levels of thioredoxin and current smoking were risk factors for coronary spastic angina, and they were independent from other traditional risk factors.

Adult↗

Intravenous administration of thioredoxin decreases brain damage following transient focal cerebral ischemia in mice.

Thioredoxin (TRX) is induced by a variety of oxidative stimuli and shows cytoprotective roles against oxidative stress. To clarify the possibility of clinical application, we examined the effects of intravenously administered TRX in a model of transient focal cerebral ischemia in this study. Mature male C57BL/6j mice received either continuous intravenous infusion of recombinant human TRX (rhTRX) over a range of 1-10 mg/kg, bovine serum albumin, or vehicle alone for 2 h after 90-min transient middle cerebral artery occlusion (MCAO). Twenty-four hours after the transient MCAO, the animals were evaluated neurologically and the infarct volumes were assessed. Infarct volume, neurological deficit, and protein carbonyl contents, a marker of protein oxidation, in the brain were significantly ameliorated in rhTRX-treated mice at the dose of 3 and 10 mg/kg versus these parameters in control animals. Moreover, activation of p38 mitogen-activated protein kinase, whose pathway is involved in ischemic neuronal death, was suppressed in the rhTRX-treated mice. Further, rhTRX was detected in the ischemic hemisphere by western blot analysis, suggesting that rhTRX was able to permeate the blood-brain barrier in the ischemic hemisphere. These data indicate that exogenous TRX exerts distinct cytoprotective effects on cerebral ischemia/reperfusion injury in mice by means of its redox-regulating activity.

Animals↗

Enhanced oxidative stress and impaired thioredoxin expression in spontaneously hypertensive rats.

As oxidative stress plays a crucial role in the development and pathogenesis of hypertension, we analyzed the redox (reduction/oxidation) status in tissues from Wistar-Kyoto rats (WKY), spontaneously hypertensive rats (SHR), and stroke-prone SHR (SHRSP). Expressions of 8-hydroxy-2'-deoxyguanosine, a marker for oxidative stress-induced DNA damage, and protein carbonylation, a marker for oxidation status of proteins, were enhanced in aorta, heart, and kidney from SHR and SHRSP compared with WKY. The expression of redox regulating protein, thioredoxin (TRX), estimated by immunohistochemistry and western blot, and expression of TRX gene estimated by real-time RT-PCR were markedly suppressed in those tissues from SHR and SHRSP compared with WKY. Induction of TRX was impaired after angiotension II treatment in peripheral blood mononuclear cells isolated from SHR and SHRSP compared with those isolated from WKY. Although previous reports have shown that TRX is induced by a variety of oxidative stress in tissues, the present study shows the impaired induction of TRX in tissues from genetically hypertensive rats despite the relative increment of oxidative stress. Redox imbalance in essential organs may play a crucial role in the development and pathogenesis of hypertension.

8-Hydroxy-2'-Deoxyguanosine↗