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S Eto

Publications and source records attributed to S Eto.

At least 73 records · Page 4Linked to original sources
PubMed1997

Regulation of interleukin (IL)-1beta gene transcription induced by IL-1beta in rheumatoid synovial fibroblast-like cells, E11, transformed with simian virus 40 large T antigen.

OBJECTIVE: To investigate the process involved in the production of and responsiveness to interleukin 1beta (IL-1beta) in synovial fibroblast-like cells, we analyzed the enhancer region of pro-IL-1beta gene in a cell clone, E11, established from a patient with rheumatoid arthritis (RA). METHODS: A cell clone, E11, was derived from rheumatoid synovial fibroblast-like cells transformed with simian virus 40 large T antigen expression vector by electroporation. Responsiveness of E11 to IL-1beta was analyzed by [3H] thymidine incorporation and Northern blotting. IL-1beta responsive elements on pro-IL-1beta gene were analyzed by chloramphenicol acetyltransferase analysis. RESULTS: E11 resembled synovial fibroblasts based on morphological characteristics and phenotypic analysis. It also demonstrated marked enhancement of proliferation and rapid induction of IL-1beta mRNA expression by IL-1beta. We also identified IL-1beta responsive elements on the pro-IL-1beta gene at a position between -3134 and -3092 that contains the AP-1 binding site and between -2782 and -2729, which includes both AP-1 and nuclear factor-kappaB (NF-kappaB) binding sites. CONCLUSION: AP-1 and NF-kappaB binding elements were required for transcriptional regulation of the IL-1beta gene in the autocrine growth system of RA synovial cells.

Antigens, Polyomavirus Transforming↗
PubMed1997

Rheumatoid synovial fibroblasts are stimulated by the cellular adhesion to T cells through lymphocyte function associated antigen-1/intercellular adhesion molecule-1.

OBJECTIVE: To determine if T cells stimulate synovial fibroblasts to produce inflammatory cytokines through cellular adhesion in synovitis of rheumatoid arthritis (RA). METHODS: Immunohistochemical staining, flow microfluorometry, adhesion assay, ELISA, and Northern blot analysis to determine production of interleukin-1beta (IL-1beta) from RA synovium and RA synovial fibroblast-like cell line. RESULTS: We observed the following novel features of cellular adhesion of T cells to synovial fibroblasts, which suggest a role for induction of cytokine production in synovial fibroblasts: (a) CD11a (lymphocyte function associated antigen-1 alpha) positive T cells accumulated around CD54 [intercellular adhesion molecule (ICAM-1)] positive synoviocytes in active RA synovium, shown by immunohistochemical studies: (b) synovial fibroblastic cell line E11 expressed a single adhesion molecule ICAM-1, the expression of which was not affected by IL-1beta; (c) E11 adhered to phorbol myristate acetate (PMA) activated T cells within 30 min, not resting T cells, and its adhesion was completely inhibited by anti-LFA-1 monoclonal antibody (Mab); (d) pretreatment of E11 with IL-1beta did not affect the adhesion of E11 to PMA activated T cells; (e) IL-1beta production and IL-1beta mRNA transcription from E11 were induced by the addition of T cells in a cell number dependent manner and the induced production and transcription were inhibited by anti-LFA-1 Mab. CONCLUSION: T cells infiltrating the synovium may play a pivotal role in the pathogenesis of RA, by inducing IL-1beta production of synovial fibroblasts by sequential events, namely, T cell-synoviocyte cellular adhesion through LFA-1/ICAM-1, signal transduction, and production of IL-1beta induced by the cellular adhesion.

Arthritis, Rheumatoid↗
PubMed1996

Structure and transcriptional regulation of human alpha-mannosidase IIX (alpha-mannosidase II isotype) gene.

Golgi alpha-mannosidase II is a key enzyme of N-glycan processing. Its genetic defect is associated with HEMPAS (hereditary erythroblastic multinuclearity with positive acidified serum lysis test). We previously cloned cDNAs of human alpha-mannosidase II (alpha-MII) and its isotype, alpha-mannosidase IIX [alpha-MIIX, Misago, M., Liao, Y. F., Eto, S., Mattei. M. G., Moremen. K. W. & Fukuda, M. N. (1995) Proc. Natl Acad. Sci. USA 92, 11766-11770]. Constitutive expressions of alpha-MII and alpha-MIIX mRNA were shown in various human tissues. To investigate the transcriptional regulation of alpha-MIIX gene, we characterized the cosmid clone of 40-kb that includes the 5'-flanking sequence. This clone contains at least eight exons which encode 396 amino acid residues of a total of 1139 amino acid residues of alpha-MIIX. Primer-extension analysis revealed multiple transcription-initiation sites in the range from -70 to -58 relative to the translation-initiation site. No canonical TATA or CAAT boxes were observed, but a (G + C)-rich region was found in close proximity to the transcription-initiation site. To localize the transcriptional regulatory region of this gene, various regions of the 5' sequences were fused to the luciferase gene, and transient-expression assays were conducted in human melanoma G-361 cells. These studies indicated that sequence from -12 to + 11 relative to the most distal 5'-transcription-initiation site was involved in the promoter function. Within this region, the sequence GGGCGT similar to the consensus sequence of the Sp1 binding site, is present at positions -12 to -7. Enhancer activities were found in the region upstream of this site, notably from -4300 to -252. Thus, the alpha-MIIX promoter located in a CpG island is also regulated by upstream elements, indicating the complexity of alpha-MIIX gene expression.

Base Composition↗
PubMed1996

Cross-linking of intercellular adhesion molecule 1 (CD54) induces AP-1 activation and IL-1beta transcription.

Leukocytes adhere to target cells through their integrins and play a crucial role in self-defense, inflammation, and differentiation. Intercellular adhesion molecule-1 (ICAM-1; CD54) is a representative ligand for integrins and is expressed on many cell types, some of which are targets for leukocyte adhesion. Recent studies suggest that adhesion molecules function not only as a cellular glue, but also as a signal transducer. However, it remains to be clearly defined whether engagement of ICAM-1 is able to induce activation signals in target cells. In rheumatoid synovium, synovial cells are known to express abundant ICAM-1 and produce multiple inflammatory cytokines, such as IL-1beta. In this study, we provide the first evidence that ICAM-1 engagement induces activation of the transcription factor AP-1 and transcription of the IL-1beta gene using a specific Ab to cross-link ICAM-1 on a rheumatoid synovial cell line (E11 cells). This evidence includes ICAM-1 cross-linking-dependent induction of 1) in situ IL-1beta transcription and protein synthesis, 2) transiently transfected chloramphenicol acetyltransferase (CAT) reporter plasmids containing both the IL-1beta LPS-responsive enhancer (between -3134 and -2729) as well as multiple copies of an AP-1 site from this enhancer (between -3117 and -3111), and 3) the binding of a Jun/Fos family complex to this AP-1 site. Thus, ICAM-1 not only functions as a glue for integrin binding, but also as a transducer for AP-1 activation signals important for IL-1beta gene transcription.

Animals↗
PubMed1996

Heparan sulfate proteoglycan on leukemic cells is primarily involved in integrin triggering and its mediated adhesion to endothelial cells.

Leukocyte migration from circulation into tissue depends on leukocyte integrin-mediated adhesion to endothelium, but integrins cannot function until activated. However, it remains to be understood how tumor cells adhere to endothelium and infiltrate into underlying tissue. We studied mechanisms of extravasation of leukemic cells using adult T cell leukemia (ATL) cells and report the following novel features of cell surface heparan sulfate proteoglycan on ATL cells in ATL cell adhesion to endothelium: ATL cells adhere to endothelial cells through already activated integrins without exogenous stimulation; different from any other hematopoietic cells, ATL cells express a characteristic heparan sulfate capable of immobilizing heparin-binding chemokine macrophage inflammatory protein (MIP)-1 beta, a potent T cell integrin trigger, produced by the cells themselves; competitive interruption of endogenous heparan sulfate proteoglycan synthesis reduces cell surface MIP-1 beta and prevents ATL cells from integrin-mediated adhesion to endothelial cells or intercellular adhesion molecule-1 triggered through G-protein. We propose that leukemic cells adhere to endothelial cells through the adhesion cascade, similar to normal leukocyte, and that the cell surface heparan sulfate, particularly on ATL cells, is pivotally involved in chemokine-dependent autocrine stimulation of integrin triggering by immobilizing the chemokine on them.

CD4-Positive T-Lymphocytes↗
PubMed1996

Interleukin-10 gene expression in adult T-cell leukemia.

We studied the serum levels of interleukin-10 (IL-10), in patients with adult T-cell leukemia (ATL) caused by human T-cell leukemia virus type I (HTLV-I) infection. Elevated IL-10 levels were observed in 33 of 45 patients with ATL. Fresh leukemic cells from ATL patients as well as HTLV-I-infected T-cell lines MT-2, SLB-1, and C10/MJ expressed IL-10 mRNA by reverse transcription-polymerase chain reaction analysis, whereas IL-10 mRNA was not detected in normal peripheral mononuclear cells and an uninfected T-cell line Jurkat. IL-10 protein was also detected in the culture medium of leukemic cells from ATL patients as well as these HTLV-I-infected cell lines, and in the extracellular fluids of ATL patients. Interestingly, MT-4 cells, which did not express Tax although transformed by HTLV-I, did not express IL-10 at either the mRNA or protein level. To elucidate the role of the HTLV-I encoded transactivator Tax in IL-10 gene expression, Jurkat cells were transfected with a Tax expression plasmid. In transiently transfected Jurkat cells, endogenous IL-10 mRNA expression was induced by Tax. Stably transfected Jurkat cell lines expressed IL-10 mRNA and secreted IL-10 protein into the culture medium. The nuclear factor (NF)-kappa B pathway is a target for Tax transactivation. We treated MT-2 cells with phosphorothioate antisense oligonucleotides to the p65 subunit of NF-kappa B. A reduction in the expression of p65 was accompanied by a reduction in IL-10 gene expression and IL-10 production. We showed that the IL-10 kappa B-like sites ( kappa B1,-2,034 to -2,025; kappa B2, -1,961 to -1,952; kappa B3, -452 to -443) specifically formed a complex with NF-kappa B-containing nuclear extract from MT-2 cells and that NF-kappa B bound with the highest affinity to the kappa B2 element (kappa B2 > kappa B3 > kappa B1). These data suggest a general role for NF-kappa B activation in the induction of IL-10 gene transcription. Activation of IL-10 in HTLV-I-infected cells may contribute to the pathology associated with HTLV-I infection.

Adult↗
PubMed1996

Chiral separation of 10,11-dihydro-10, 11-trans-dihydroxycarbamazepine, a metabolite of carbamazepine with two asymmetric carbons, in human serum.

Chiral separation of 10, 11-dihydro-10, 11-trans-dihydroxycarbamazepine (CBZ-diol), a metabolite of carbamazepine (CBZ) with two asymmetric carbons, in serum taken from epileptic patients receiving CBZ alone for a long period, was performed by high-performance liquid chromatography using a polysaccharide stationary phase with n-hexane-ethanol (75:25, v/v) as the mobile phase. The enantiomeric ratio (S,S-/R,R-CBZ-diol) was 10.74 +/- 1.13 (mean +/- S.D.), which could demonstrate the presence of the stereospecificity in the hydrolysis of 10, 11-dihydro-10, 11-epoxycarbamazepine (CBZ-epoxide) to CBZ-diol and/or in the conversion of CBZ-diol to some metabolite such as 9-hydroxymethyl-10-carbamoylacridan. This is the first paper to report the determination of each enantiomer and the enantiomeric ratio of CBZ-diol in serum of epileptic patients who received CBZ.

Carbamazepine↗
PubMed1996

Determination of isonicotinic acid in the presence of isoniazid and acetylisoniazid. Studies on isonicotinic acid formation from isoniazid in isolated rat hepatocytes.

In comparison with the hepatocytes obtained from intact rats and rats pretreated with phenobarbital or 3-methylchoranthrene, the amount of isonicotinic acid (INA) formed from isoniazid (INH) increased substantially after incubation at 37 degrees C using the pretreated hepatocytes. This suggests an oxidative pathway for INA formation from INH, apart from hydrolysis. In order to explore the exact mechanism of INA formation in the hepatocytes, an HPLC assay for INA in the presence of INH and acetylisoniazid was developed. In this assay, INA was extracted after the preparation of an ion pair with tetra-n-butylammonium hydroxide, and analysed using an ODS column and a mobile phase consisting of 0.067 M potassium dihydrogenphosphate solution-methanol (96:4, v/v). The method is simple, accurate and especially suitable for INA determination after incubation of INH in isolated rat hepatocytes.

Animals↗
PubMed1996

Characterization and regulation of interleukin-4 receptor in adult T-cell leukemia cells.

We studied the expression of the receptor of interleukin (IL-4), one of the T cell growth factors, on fresh peripheral blood leukemic cells from adult T-cell leukemia (ATL) patients. Flow cytofluorometric analysis with a monoclonal antibody to the IL-4 receptor (IL-4R) were used to investigate whether expression of IL-4R on ATL cells is different from that on normal lymphocytes and other types of leukemic cells. Leukemic cells from acute type ATL patients synthesize IL-4R without stimulation, at levels much higher than normal resting lymphocytes and other types of leukemic cells. Furthermore, leukemic cells from acute type ATL showed higher IL-4R expression than that of chronic type ATL or human T-cell leukemia virus type I carriers. In addition, there was correlation between expression of IL-4R on the cell surface and the proliferative response to IL-4. Both IL-4 and IL-2 induced upregulation of IL-4R on activated normal T cells but not on ATL cells. These results suggest that abnormal expression of IL-4R may display different biological activities in ATL compared with other types of leukemia. Furthermore, the high expression of IL-4R in ATL may be involved in the proliferation of leukemic cells and the leukemogenesis in this disease.

Adult↗
PubMed1996

[A clinical evaluation of fluconazole in deep seated fungal infections associated with hematological disorders].

The effectiveness of fluconazole on deep seated fungal infections associated with hematological disorders was evaluated in a multicenter clinical study. The underlying diseases included acute myeloblastic leukemia, acute lymphocytic leukemia, malignant lymphoma, adult T cell leukemia, multiple myeloma and others. Fluconazole (FLCZ) was administrated 100-400 mg/day intravenously or orally to 79 patients with systemic fungal infections complicated with hematological disorders and it was possible to evaluate clinical efficacies in 60 patients. 27 patients were diagnosed as having determinate systemic fungal infections and 33 patients suspected fungal infections. The clinical efficacies were 81.5% (22/27) in patients with diagnosed fungal infections and 57.6% (19/33) in patients with suspected fungal infections. The overall clinical efficacy was 68.3% (41/60). No side effects such as gastrointestinal symptoms, vascular pain and renal dysfunction were observed in this study. As for abnormal laboratory test, transient increases in GOT, GPT, Al-P, LDH, serum Na, Cl and decrease in serum K were observed in 9 patients (11.4%). These results indicated that FLCZ has a high therapeutic efficacy on deep seated fungal infections in patients with hematological disorders.

Aged↗
PubMed1995

Molecular cloning and expression of cDNAs encoding human alpha-mannosidase II and a previously unrecognized alpha-mannosidase IIx isozyme.

Golgi alpha-mannosidase II (alpha-MII) is an enzyme involved in the processing of N-linked glycans. Using a previously isolated murine cDNA clone as a probe, we have isolated cDNA clones encompassing the human alpha-MII cDNA open reading frame and initiated isolation of human genomic clones. During the isolation of genomic clones, genes related to that encoding alpha-MII were isolated. One such gene was found to encode an isozyme, designated alpha-MIIx. A 5-kb cDNA clone encoding alpha-MIIx was then isolated from a human melanoma cDNA library. However, comparison between alpha-MIIx and alpha-MII cDNAs suggested that the cloned cDNA encodes a truncated polypeptide with 796 amino acid residues, while alpha-MII consists of 1144 amino acid residues. To reevaluate the sequence of alpha-MIIx cDNA, polymerase chain reaction (PCR) was performed with lymphocyte mRNAs. Comparison of the sequence of PCR products with the alpha-MIIx genomic sequence revealed that alternative splicing of the alpha-MIIx transcript can result in an additional transcript encoding a 1139-amino acid polypeptide. Northern analysis showed transcription of alpha-MIIx in various tissues, suggesting that the alpha-MIIx gene is a housekeeping gene. COS cells transfected with alpha-MIIx cDNA containing the full-length open reading frame showed an increase of alpha-mannosidase activity. The alpha-MIIx gene was mapped to human chromosome 15q25, whereas the alpha-MII gene was mapped to 5q21-22.

Alternative Splicing↗
PubMed1995

Calcium-dependent homotypic adhesion through leukocyte function-associated antigen-1/intracellular adhesion molecule-1 induces interleukin-1 and parathyroid hormone-related protein production on adult T-cell leukemia cells in vitro.

Adult T-cell leukemia (ATL) is a human T-cell leukemia virus type I (HTLV-I)-infected lymphoproliferative disorder that shows a characteristic nodular infiltration into various tissues, hypercalcemia, and subsequent rapid increase of peripheral ATL cell number. ATL cells and HTLV-I-infected T-cell lines also make cluster formation rapidly after the non-stimulative culture. However, the mechanism of the acute proliferation of ATL cells remains to be understood. We report the following novel features of homotypic adhesion via leukocyte function-associated antigen-1 (LFA-1)/intracellular adhesion molecule-1 (ICAM-1) pathway that suggest a role for it in cytokine production and rapid proliferation of ATL cells: (1) ATL cells show clustering in a calcium dependent manner, even at the higher concentration; (2) ATL cells consistently and highly express ICAM-1 and an active form of LFA-1, whereas integrin expression, except for LFA-1, is rather lower compared with that of normal CD4+ T cells; (3) ATL cells make conjugate formation within 6 minutes and clustering within 48 hours, both of which are inhibited by the addition of monoclonal antibodies (MoAbs) against LFA-1 and ICAM-1; (4) spontaneous mRNA transcription and protein secretion of both interleukin-1 and parathyroid hormone-related protein are observed consistently in ATL cells, and these productions are inhibited by anti-LFA-1 and anti-ICAM-1 MoAbs but are markedly increased by cross-linking of LFA-1 and ICAM-1 by the immobilized specific MoAbs; and (5) proliferative responses of ATL cells are also inhibited by these MoAbs. We propose that ATL cells proliferate in sequential events: the homotypic and calcium-dependent adhesion through LFA-1/ICAM-1, the signal transduction through these adhesion molecules, the production of cytokines, and the proliferation.

Bone Resorption↗
PubMed1995

Production of interleukin 8 in adult T-cell leukemia cells: possible transactivation of the interleukin 8 gene by human T-cell leukemia virus type I tax.

Interleukin 8 (IL-8) mRNA was detected in peripheral leukemic cells obtained from adult T-cell leukemia patients, as well as in cultured human T-cell leukemia virus type I (HTLV-I)-infected T-cell lines (HUT-102, MT-1, SALT-3, and SKT-1B). With the use of ELISA, IL-8 protein was also detected in the culture medium of these cells and in the extracellular fluids of patients. Furthermore, we demonstrated that the HTLV-I-derived transactivator protein, tax, could stimulate endogenous IL-8 gene expression in an uninfected T-cell line (Jurkat) and in a rheumatoid synovial cell line (E-11). Induction of IL-8 by tax at protein level was also demonstrated in transfected cells. We found that the IL-8 NF-kappa B-binding site specifically formed a complex with NF-kappa B-containing nuclear extracts from HTLV-I-infected T-cell lines and freshly isolated leukemic cells from adult T-cell leukemia patients. Finally, transfection of HTLV-I tax into Jurkat cells resulted in induction of specific binding of nuclear extracts to the NF-kappa B sequence. These results suggest that the HTLV-I tax gene may transactivate the IL-8 gene through the kappa B site in HTLV-I-infected cells and that constitutive expression of the IL-8 gene may play a role in HTLV-I-associated pathogenesis.

Acute Disease↗
PubMed1995

Cardiovascular-related peptides influence hypothalamic neurons involved in control of body water homeostasis.

The cardiovascular-related peptides, atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and endothelin (ET) were originally isolated from the atrium, brain and endothelial cells, respectively. ANP and BNP have hypotensive, natriuretic, diuretic and vasodilator effects. ET has strong vasoconstrictor effects. Centrally applied ANP and BNP attenuate pressure and drinking responses and vasopressin secretion induced by angiotensin II. Similar application of ET increases blood pressure in vivo and vasopressin secretion in vitro. To clarify direct effects of these peptides on neurons in the regions involved in body water homeostasis, extracellular recordings were made from neurons in the supraoptic nucleus (SON) and regions of anteroventral third ventricle (AV3V) of rat hypothalamic slice preparations. ANP and BNP inhibited AV3V neurons, suggesting direct actions of the peptides on drinking. In the SON, these peptides inhibited selectively putative vasopressin neurons but not putative oxytocin neurons, suggesting direct actions of the peptides on vasopressin secretion. We demonstrated that the inhibitory response by ANP and BNP is mediated through a second messenger cGMP system but not cAMP. Contrary to natriuretic peptides, ET excited AV3V neurons but inhibited SON neurons. Roles of ANP, BNP and ET on the central regulatory systems of body water homeostasis, acting as neurotransmitters or neuromodulators, will be discussed.

Animals↗
PubMed1995

Osteoblasts are regulated by the cellular adhesion through ICAM-1 and VCAM-1.

The two major processes of bone metabolism--bone formation and resorption--are regulated by cellular interactions. Osteoblasts and osteoclasts play a significant role in bone metabolism, which is known to be regulated by local soluble factors and systemic hormones. Although bone is a heterogeneous tissue comprised of osteogenic and hematopoietic cells, cellular adhesion of osteoblasts and its regulation remains to be understood. We first demonstrate that cellular adhesion by which osteoblasts communicate with opposing cells in bone milieu is involved in the osteoblast activation: (a) purified human osteoblasts obtained from osteoarthritis patients expressed particular adhesion molecules, ICAM-1, VCAM-1, and LFA-3; (b) toe osteoblasts adhered to T cells which were used as representative adhesive partners, since T cells possess all the receptors to these adhesion molecules; (c) mRNA transcription and secretion of IL-1beta and IL-6 were induced in the osteoblasts by the cellular adhesion to T cells and they were reduced by interrupting the adhesion; (d) cross-linking of ICAM-1 and VCAM-1 on the osteoblasts induced IL-6 secretion from the osteoblasts. These results indicate that osteoblasts adhere to opposing cells through particular adhesion molecules on their surface and that the adhesion molecules on the osteoblasts not only function as glue with opposing partners but transduce activation signals that facilitate the production of bone-resorbing cytokines. We propose that cellular adhesion of osteoblasts as well as soluble factors is significant for the regulation of bone metabolism.

Base Sequence↗