Search PubMed⌕ Search

Biomedical subjects

H Masutani

Publications and source records attributed to H Masutani.

At least 55 records · Page 3Linked to original sources

Induction of ADF/TRX by oxidative stress in keratinocytes and lymphoid cells.

Adult T-cell leukemia-derived factor (ADF)/human thioredoxin (TRX) has thiol-dependent reducing activities and is known to have regulatory roles on the DNA-protein interaction and cell activation. Inducive effect of ultraviolet (UV) has been indicated because of the enhanced expression of ADF/TRX in epidermal cells of sun-exposed skin, as determined by immunohistochemical staining with antibody against recombinant ADF (rADF). We studied the effect of UVB irradiation and other oxidative stress on the expression of ADF/TRX in epithelial cells as well as lymphoid cells, as HTLV-1 and Epstein-Barr virus-transformed lymphoid cells constitutively produce ADF/TRX. Using immunohistochemical staining anti-ADF antibody, the enhancement of ADF/TRX expression on primary culture of human keratinocytes was demonstrated, 12 h after 20 mJ/cm2 UVB irradiation. Western blot analysis of the ADF/TRX protein in the cell lysates also showed the significant induction. In in situ hybridization, induction of ADF/TRX mRNA was detected after 4 h of UV exposure. ADF/TRX was also induced in a HTLV-1 (+) T-cell line, MT-1, by UVB or H2O2 dose dependently. The augmentation of ADF/TRX was observed 6 h after treatment of H2O2.

Blotting, Western↗

Biochemical and topological analysis of adult T-cell leukaemia-derived factor, homologous to thioredoxin, in the pregnant human uterus.

Adult T-cell leukaemia-derived factor (ADF), homologous to thioredoxin, displays various biological activities, such as radical scavenging action and the reduction of protein disulphide bonds. We examined the biochemical and immunohistochemical localization of ADF in the pregnant human uterus, using two heteroantibodies to ADF, antibody C and W. Immunohistochemically, decidua and trophoblast cells were intensely stained by antibody C. The concentration of ADF-like substance in the decidua was 95.9 ng/mg protein, determined by enzyme-linked immunosorbent assay. The molecular weight of ADF-like substance in these tissues was determined by gel electrophoresis to be 13 kDa, the same as that of recombinant ADF. These findings indicate that abundant ADF is present in decidua and trophoblast cells; the localization of such a potent dithiol reducing substance may be beneficial in protecting the fertilized egg and placental trophoblasts from the cytotoxic effects of oxygen radicals.

Adult↗

Purification and characterization of secretory-type GDP-L-fucose: beta-D-galactoside 2-alpha-L-fucosyltransferase from human gastric mucosa.

alpha-(1,2)-Fucosyltransferase (GDP-L-fucose:beta-D-galactoside 2-alpha-L-fucosyltransferase) from human gastric mucosa was purified to homogeneity by column chromatographies on Ultrogel AcA34, phenyl-Sepharose, hydroxylapatite, SP-Sephadex, and GDP-hexanol-amine Sepharose. The molecular weight of the purified enzyme was estimated to be 65,000 by SDS-PAGE. The Km value of this enzyme for a type 1 sugar acceptor was a little smaller than that for a type 2 one, indicating this enzyme is a secretor-type alpha-(1,2)-fucosyltransferase. However, the difference between the Km value for a type 1 precursor and that for a type 2 one was very small, suggesting that this enzyme can use both types of precursors as sugar acceptors approximately equally, unlike the purified alpha-(1,2)-fucosyltransferase from human serum as the secretor-type reported previously. The characteristics of the purified enzyme were compared with those of H-type alpha-(1,2)-fucosyltransferase from human plasma. The activities of both enzymes were inhibited by salt and N-ethylmaleimide, but they showed a significant difference in their divalent cation requirements.

Carbohydrate Metabolism↗

Microvascular disorder of the stria vascularis in endolymphatic hydrops.

To investigate the role of pathology of the stria vascularis in endolymphatic hydrops, the vascularity and atrophy of the stria were examined by histological observation in guinea pig temporal bones affected by experimental endolymphatic hydrops. Blood cell sludge and vasoconstriction accompanied by strial atrophy were observed in the coiled arteriole and capillary of the stria vascularis of the ear with endolymphatic hydrops after exposure to noise, suggesting the development of inner ear circulatory disturbance. Furthermore, these findings were observed around the upper turn of the cochlea. The effect of glycerol and difenidol hydrochloride on endolymphatic hydrops was also examined. Vasoconstriction and blood cell sludge disappeared following administration of these agents, accompanied by collapse. These findings suggest the possibility that the circulatory disturbance might be the cause of endolymphatic hydrops, followed by strial atrophy.

Animals↗

[Pulmonary complications in patients with rheumatoid arthritis].

Pulmonary manifestations of rheumatoid arthritis were studied in 26 patients. Pulmonary complications could be divided into four subgroups: Interstitial pneumonia/Pulmonary fibrosis (n = 18), Bronchiolitis Obliterans Organizing Pneumonia (n = 4), Bronchiolitis Obliterans (n = 2), and Pleuritis/Pericarditis (n = 1). Analysis of cells in broncho-alveolar lavage fluid (BALF) revealed abnormally high percentages of lymphocytes in one-half of the patients and abnormally high percentages of neutrophils in one-third of the patients. The percent of BALF cells that were neutrophils was higher with higher chest radiograph grades. Analysis of soluble constituents of BALF indicated local production of IgG in two cases, but IgM-rheumatic factor was not detected. In 18 of 26 patients corticosteroid or immunosuppressive drugs were needed, and most of the patients responded to the therapy and had good outcomes. The conditions of 6 patients with interstitial pneumonia/pulmonary fibrosis deteriorated and 4 patients died of progressive respiratory failure. The subclassification of rheumatoid lung was useful for predicting its outcome.

Aged↗

Cell cycle inhibition of HTLV-I transformed T cell lines by retinoic acid: the possible therapeutic use of thioredoxin reductase inhibitors.

Adult T cell leukemia derived factor (ADF), which was first reported as a cytokine-like factor produced by human T lymphotropic virus I (HTLV-I)-transformed T cells, is a human homologue of thioredoxin (TRX). ADF/TRX has multiple functions including growth promoting, antiapoptotic and radical scavenging activities, and is also involved in a wide variety of intracellular processes as a dithiol reducing agent in cooperation with the NADPH-TRX reductase system. In HTLV-1(+) T cell lines, HuT 102 and MT-2, which are ADF/TRX high producing cells, we found that the expression of ADF/TRX was dependent on the cell cycle and peaked at S phase. The reducing activity of ADF/TRX in these cells was also dependent on the cell cycle and elevated in S phase as determined by NADPH-dependent insulin degradation assay. Furthermore, inhibitors of TRX reductase, 13-cis-retinoic acid (13-cis-RA) and azelaic acid, inhibited the DNA synthesis of these cells. In contrast, the residual expression and reducing activity of ADF/TRX in HTLV-I(-) T cell lines did not show any significant correlation with the cell cycle. There was no distinct inhibitory effect of 13-cis-RA or azelaic acid on the growth of these ADF/TRX low producing cells. These results indicate that a high level of reducing activity of the ADF/TRX system may be required for the cell division of these virally transformed cells. This suggests that the TRX reductase inhibitors including retinoid derivatives have a potential therapeutic utility for treatment of HTLV-1(+) T cell leukemia without any effect on HTLV-I(-) cells.

Cell Cycle↗

Thiol-mediated redox regulation of lymphocyte proliferation. Possible involvement of adult T cell leukemia-derived factor and glutathione in transferrin receptor expression.

The proliferative response of PBMC to PHA, Con A, OKT3 mAb and IL-2-dependent proliferation of PHA-blasts was examined in a thiol-free environment (cultured in a L-cystine- and GSH-free medium). [3H]TdR incorporation assay and cell cycle analysis revealed that stimulated PBMC could not enter the S phase when deprived of these thiol compounds. In thiol-free cultures, an increase in intracellular free Ca2+ concentration and IL-2R alpha-chain/p 55 (Tac) induction was still observed, whereas transferrin receptor induction was markedly reduced, suggesting that the proliferative response of mitogenically stimulated PBMC was arrested in the late G1 phase in which transferrin receptor is induced. In GSH-depleted cultures, a similar reduction of the proliferative response of PBMC and PHA-blasts was observed when the concentration of L-cystine was lowered, in a dose-dependent manner. Each reduction or loss of proliferative response was partially restored by supplementation of 2-ME or adult T cell leukemia-derived factor (ADF)/human thioredoxin which is considered to be an endogenous dithiol-reducing factor. L-Cystine transport analysis showed that mitogenically stimulated PBMC and PHA blasts incorporated L-cystine, whereas resting PBMC did not. Furthermore, ADF as well as 2-ME exhibited an enhancing activity on the L-cystine transport in PHA blasts. Together with the fact that L-cystine transport is a limiting step in glutathione synthesis, these findings suggest that GSH and ADF might cooperate in the thiol-mediated redox regulation process and might also play key roles in cell cycle (late G1 to S) progression of activated lymphocytes.

Amino Acid Sequence↗

Detection of adult T-cell leukemia-derived factor/human thioredoxin in human serum.

Adult T-cell leukemia (ATL)-derived factor (ADF), originally defined as an inducer of interleukin-2 receptor/alpha-chain (IL-2R/p55) of human T-lymphotropic virus type I (HTLV-I) positive T cells, is a human homologue of redox-active coenzyme thioredoxin (Trx) of Escherichia coli. In this study, an enzymatic assay system based on the dithiol-dependent insulin-reducing activity of ADF/Trx was established (insulin-reducing assay) to determine the amount of ADF/Trx in human serum using NADPH and Trx reductase purified from human placenta. Insulin-reducing activity was detected in all of the serum samples from healthy volunteers (n = 30) screened by this assay, with a mean +/- SD of 10.9 +/- 2.4 U/l. This mean value corresponds with the concentration of 223 ng recombinant ADF/Trx (rADF/Trx)/ml. Human serum is known to contain several redox-active proteins with ADF/Trx motifs. To differentiate the contribution of these proteins and ADF/Trx to the insulin-reducing activity, the anti-rADF/Trx monoclonal antibody (mAb)-conjugated affinity column-depleted sera obtained from an identical source was used for analysis. The affinity column-depleted sera demonstrated a loss of over 99% of the original activity, while control column depleted sera lost less than 4%. Furthermore, the amount of affinity-purified ADF/Trx molecules eluted from the same column almost corresponded with the amount estimated by the insulin-reducing activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Prognosis of idiopathic interstitial pneumonia].

Idiopathic interstitial pneumonia (IIP) is characterized by chronic inflammation and fibrosis of the lung. It carries a poor prognosis and the treatment for IIP has not yet been established. We evaluated 116 cases of IIP retrospectively, and analyzed possible prognostic factors, such as the mode of detection, clinical symptoms, chest X-ray findings, pulmonary function tests, blood chemistry, bronchoalveolar lavage (BAL), and treatments. The 5-year survival rate from the onset was 39.5% and the 10-year survival rate was only 12.7%. The 5-year survival rate from the appearance of dyspnea on exertion was 23.2% and 10-year survival rate was 9.0%. According to the results of the Kaplan-Meier analysis, patients with low% FVC (< 70%), those with high values of ESR, those with high values of CRP, and those with advanced chest X-ray shadows did not survive as long as other patients. Multivariate analysis with a proportional hazards model revealed that a high percentage of eosinophils in BALF was associated with a poor prognosis. Analysis with a logistic model revealed that being male having a low %DLCO were associated with a poor prognosis.

Female↗

[A case of subcutaneous sarcoid nodules induced by interferon-alpha].

A 57-year-old woman came to our hospital complaining of multiple subcutaneous nodules that developed while she received corticosteroid therapy for pulmonary sarcoidosis. She was treated with interferon-alpha (IFN-alpha) at another hospital for C-type chronic hepatitis and she noticed these nodules with tenderness two months after treatment began. A biopsy specimen of the nodule revealed subcutaneous sarcoid granuloma. Her abnormally high serum-ACE value and subcutaneous nodules resolved after the dose of IFN-alpha was gradually reduced. IFN therapy should be used with care in cases of sarcoidosis in which IFN-gamma and T-lymphocytes are mainly involved.

Female↗

Marked apoptosis of human myelomonocytic leukemia cell line P39: significance of cellular differentiation.

Myelodysplastic syndrome (MDS)-derived leukemia cell line P39/Tsugane could be induced to apoptosis by a variety of agents including metabolic inhibitors, a calcium ionophore and differentiation-inducing agents. As evaluated by characteristic morphological changes and oligonucleosomal lengths DNA ladder, the levels of apoptosis in P39 cells induced by actinomycin D, or A23187, were far greater than in other myeloid lines examined in this study. When 22-oxa-1 alpha, 25(OH)2D3 (D3), dimethyl sulfoxide (DMSO) and all-trans retinoic acid (RA) were used as differentiation-inducers, varying degrees of apoptosis were seen. D3 induced monocytoid differentiation, but not apoptosis above the control level. On the other hand, RA induced profound apoptosis concomitant with the progressive expression of differentiation markers. Studies on morphology, functions and phenotypes of P39 cells exposed to differentiation inducers suggest that the incidence of apoptosis was not affected by the process of differentiation, but cells in the process of varying degrees of differentiation may die via apoptosis. Moreover, RA-treated P39 cells are unique in the simultaneous occurrence of profound apoptosis and differentiation. We propose that RA-treated P39 differentiation model is ideally suited for the study of MDS.

Apoptosis↗

Oxidative stress induces adult T cell leukemia derived factor/thioredoxin in the rat retina.

BACKGROUND: Adult T cell leukemia derived factor (ADF), originally defined as an interleukin-2 receptor inducer, is a human thioredoxin homolog. ADF/thioredoxin has several biologic functions, such as defense against cellular damage, activity to scavenge oxidative stress by hydrogen peroxide radicals and cytokine-like properties. We hypothesized that under certain conditions, ischemia followed by reperfusion and/or light exposure, ADF may be induced in the retina. EXPERIMENTAL DESIGN: To test this hypothesis, we prepared experimental animal models in which oxidative stress could be applied to the retina. In the present study, we examined ADF expression in the rat retina using temporary ischemia and reperfusion, and photodynamic retinal vascular thrombosis by immunohistochemical and Western blotting methods. RESULTS: ADF expression was strongly induced in the retinal pigment epithelial cells after 2 hours of ischemia followed by 2, 24, or 48 hours of reperfusion. ADF was also expressed in retinal pigment epithelial cells as early as 3 hours after light exposure followed by rose bengal injection, and this expression increased with time. Western blotting data showed that ADF expression increased in the retinal pigment epithelial cells in the experimental group, as compared with the control group. These results indicate that ADF is actively induced in retinal pigment epithelial cells upon oxidative stress. CONCLUSIONS: ADF induction in retinal pigment epithelial cells may be involved in the defense mechanism against cellular damage caused by active oxygen species generated during oxygen stress to the retina.

Animals↗

Mitochondrial induction of adult T cell leukemia derived factor (ADF/hTx) after oxidative stresses in retinal pigment epithelial cells.

PURPOSE: Adult T cell leukemia derived factor (ADF) is a human homologue of thioredoxin (hTx), which exhibits scavenging activity with reactive oxygen intermediates. In their previous study, the authors found that after transient retinal ischemia, the expression of thioredoxin in rat retinal pigment epithelium (RPE) layer increased markedly. The present investigation is to determine intracellular ADF localization in RPE after transient ischemia and in cultured human RPE cells after oxidative insult by H2O2. METHODS: The authors employed immunoelectron microscopy to examine ADF localization in RPE. Labeling density analysis was performed to supplement the main observation in the experiment of transient retinal ischemia. 3-(4,5-dimethylthiazol-2yl)-2-5-diphenyltetrazolium bromide (MTT) assay was performed to verify the protective role of recombinant ADF (rADF) against H2O2. RESULTS: In immunogold electron microscopy, sparse ADF-positive labeling was seen in the cytosol and mitochondria in normal rat RPE and in untreated cultured RPE cells. After oxidative stress, it was concentrated in mitochondria in both groups. MTT assay proved that rADF protected cultured RPE from the toxicity of H2O2. CONCLUSIONS: This study shows the induction of ADF/hTx in mitochondria of RPE after oxidative stresses and its protective effect on cultured RPE exposed to H2O2. The data indicate the possibly important role of ADF/hTx in the protection of retinal cells from the oxidative stresses associated with retinal ischemic disease and probably with regular visual activity.

Adult↗

Detection of Mg(2+)-dependent endonuclease activity in myeloid leukemia cell nuclei capable of producing internucleosomal DNA cleavage.

We detected Mg(2+)-dependent, Ca(2+)-independent endonuclease activity in non-apoptotic myeloid leukemia cell nuclei using autodigestion method which cleaved the chromatin of the autologous leukemia cells to an oligonucleosomal length pattern. Similar endonuclease activity could be successfully recovered in the protein extracts of the human leukemia cell nuclei. The extracts consistently elicited characteristic DNA cleavage of another leukemia cell (KG-1) nuclei as the target, the enzyme activity of which had been inactivated. We propose that this method is a useful tool for the study of endonucleases involved in apoptosis.

Animals↗

Expression and growth-promoting effect of adult T-cell leukemia-derived factor. A human thioredoxin homologue in hepatocellular carcinoma.

Adult T-cell leukemia-derived factor (ADF), originally defined as an interleukin-2 receptor inducer, is a human thioredoxin homologue. ADF is detected in many malignant tissues and has a growth-promoting effect on transformed cells. In this study, ADF expression was examined immunohistochemically in human liver cell lines and liver tissues, and its growth-promoting effect was tested on human hepatoma cells. On three liver cell line--PLC/PRF/5, HepG2, and Chang liver cells--ADF stained positively and also was detected by immunoblotting. ADF had strong staining in the fetal liver (n = 8), although it was faint in the normal adult liver (n = 6). In hepatocellular carcinoma (n = 25), ADF expression generally was enhanced and was very strong in 52% (13 of 25) of the cases, although it was moderate in cases of chronic hepatitis or cirrhosis. ADF augmented the growth of PLC/PRF/5 cells and showed an additive effect with epidermal growth factor. These results indicate possible involvement of ADF in cell activation and growth of hepatocytes, as is the case with lymphocytes.

Carcinoma, Hepatocellular↗