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Biomedical subjects

J Inoue

Publications and source records attributed to J Inoue.

At least 91 records · Page 5Linked to original sources

Sterol-dependent transcriptional regulation of sterol regulatory element-binding protein-2.

We show in this manuscript that expression of the mRNA for sterol regulatory element-binding protein-2 (SREBP-2) is regulated by the cellular sterol level in cultured HeLa cells. We have cloned the 5'-flanking region of the gene encoding human SREBP-2. Characterization of this region shows the minimum 50-base pair segment, which contains a 10-base pair sterol regulatory element 1 (SRE-1) identical to the one in the human LDL receptor promoter, confers sterol responsiveness when fused to the luciferase reporter gene. Enforced expression of the truncated SREBP-2 protein (amino acid residues 1-481) also shows that this upstream segment contains the information required for transcriptional activation. The luciferase assays using mutant versions of the reporter genes reveal that the sterol-dependent transcriptional regulation is mediated by two nearby motifs, the SRE-1 and the NF-Y binding site (the inverted CCAAT box, ATTGGC); the latter is reported to play a critical role in sterol-dependent regulation of 3-hydroxy-3-methylglutaryl-coenzyme A synthase and farnesyl diphosphate synthase genes (Jackson, S. M., Ericsson, J., Osborne, T. F., and Edwards, P. A. (1995) J. Biol. Chem. 270, 21445-21448). Gel mobility shift assays demonstrate that the transcription factor NF-Y truly binds to the ATTGGC sequence. These findings suggest that the activity of SREBP-2 is controlled not only post-translationally by proteolytic activation of the precursor protein but also transcriptionally by itself together with NF-Y.

Binding Sites↗

A variant CD30 protein lacking extracellular and transmembrane domains is induced in HL-60 by tetradecanoylphorbol acetate and is expressed in alveolar macrophages.

We identified and cloned cDNAs for two novel CD30 mRNAs of 2.3 kb that are induced by 12-O-tetradecanoylphorbol 13-acetate (TPA) in the human myeloid leukemia cell line HL-60. These transcripts were transcribed from the intronic region just upstream of the exon coding for the transmembrane domain of the CD30 protein. The shorter cDNA had a deletion of 54 nucleotides corresponding to the 3' region of the transmembrane domain of the CD30 and which was probably caused by alternative splicing. Translation of these transcripts appeared to start from the internal methionine codon at nucleotide position 289 that corresponds to that of 1612 in the CD30 cDNA, and encode a protein of 132 amino acid residues which corresponds exactly to the C-terminal cytoplasmic domain of CD30 protein. The calculated molecular mass of this variant CD30 (CD30v) protein was 14,087. Thus, the predicted CD30v protein retains most of the cytoplasmic region, but lacks the extracellular and transmembrane domains. Northern blots detected the expression of CD30v transcripts only in the lung and the TPA-stimulated HL-60 cell line. Translation of this mRNA in vitro produced a protein of 25 kD. Immunoblotting analysis with HCD30C1, a rabbit polyclonal antibody raised against the cytoplasmic domain of CD30 protein, detected proteins with an apparent Mr 25 kD expressed in TPA-stimulated HL-60 and COS-7 cells that were transfected with both types of CD30v cDNAs. Constitutive phosphorylation of the CD30v protein was demonstrated by in vitro labeling with [32P]. Immunohistochemical studies demonstrated CD30v protein was in alveolar macrophages. Cotransfection experiments using a kappa B-site-dependent reporter construct showed that CD30v can transactivate gene expression through activation of NF kappa B, as was noted on the authentic CD30 protein. Overexpression of the CD30v induced differentiation of HL-60 cells as evidenced by an increased NBT reduction activity. These observations provided new insights into the molecular heterogeneity and biological function of CD30 in myeloid cells.

Animals↗

TRAF5, a novel tumor necrosis factor receptor-associated factor family protein, mediates CD40 signaling.

Signals emanating from CD40 play crucial roles in B-cell function. To identify molecules that transduce CD40 signalings, we have used the yeast two-hybrid system to done cDNAs encoding proteins that bind the cytoplasmic tail of CD40. A cDNA encoding a putative signal transducer protein, designated TRAF5, has been molecularly cloned. TRAF5 has a tumor necrosis factor receptor-associated factor (TRAF) domain in its carboxyl terminus and is most homologous to TRAF3, also known as CRAF1, CD40bp, or LAP-1, a previously identified CD40-associated factor. The amino terminus has a RING finger domain, a cluster of zinc fingers and a coiled-coil domain, which are also present in other members of the TRAF family protein except for TRAF1. In vitro binding assays revealed that TRAF5 associates with the cytoplasmic tail of CD40, but not with the cytoplasmic tail of tumor receptor factor receptor type 2, which associates with TRAF2. Based on analysis of the association between TRAF5 and various CD40 mutants, residues 230-269 of CD40 are required for the association with TRAF5. In contrast to TRAF3, overexpression of TRAF5 activates transcription factor nuclear factor kappa B. Furthermore, amino-terminally truncated forms of TRAF5 suppress the CD40-mediated induction of CD23 expression, as is the case with TRAF3. These results suggest that TRAF5 and TRAF3 could be involved in both common and distinct signaling pathways emanating from CD40.

Amino Acid Sequence↗

MEK kinase is involved in tumor necrosis factor alpha-induced NF-kappaB activation and degradation of IkappaB-alpha.

Signal-dependent activation of the transcription factor NF-kappaB is dominantly regulated by degradation of IkappaB-alpha protein. However, the signaling pathways that lead to the degradation are not clear. Here we report that mitogen-activated protein kinase/extracellular signal-regulated kinase kinase (MEK) kinase, an activator of stress-activated protein kinases/jun kinase-1 (SAPKs/JNK1), is involved in such signaling pathways. The transient overexpression of MEK kinase in NIH3T3 fibroblasts activates kappaB-CAT reporter expression in a synergistic manner with TNFalpha stimulation. In contrast, overexpression of kinase-negative MEK kinase suppresses TNFalpha-induced reporter expression. The overexpression of MEK kinase suppresses the inhibitory activity of co-transfected IkappaB-alpha on the kappaB-CAT or human immunodeficiency virus-long terminal repeat-luciferase reporter expression and causes the simultaneous disappearance of the overexpressed IkappaB-alpha. The disappearance of exogenous IkappaB-alpha by the overexpression of MEK kinase is prevented by calpain inhibitor-I, an inhibitor of IkappaB-alpha degradation. These results suggest that MEK kinase is a signal mediator involved in TNFalpha-induced NF-kappaB activation and that the activation of NF-kappaB by MEK kinase is regulated through the degradation of IkappaB-alpha.

3T3 Cells↗

Activation of the retinoblastoma gene expression by Bcl-3: implication for muscle cell differentiation.

The retinoblastoma (Rb) protein is a master regulator of cell cycle. Accumulating evidence suggests that elevation of Rb expression is a key event in differentiation of various cell types. However the mechanism of regulation of Rb expression is poorly understood. Here we report that the candidate oncoprotein Bcl-3, previously characterized as a member of the IkappaB family, activates transcription of the Rb gene, whose promoter has no typical kappaB sites. A target element for Bcl-3 that matches the consensus for the E4TF1/GABP transcription factor was identified. Bcl-3 was shown to promote tetramer formation of E4TF1. During muscle cell differentiation, increased bcl-3 expression was observed before the induction of the Rb mRNA. Transient expression of Bcl-3 in myoblasts was shown to induce expression of the endogenous Rb. Furthermore, expression of the antisense bcl-3 RNA in myoblasts suppressed induction of Rb and myogenic differentiation. These results suggest that Bcl-3 is an upstream regulator of Rb expression during differentiation of muscle cells.

B-Cell Lymphoma 3 Protein↗

Inhibitory effect of tannic acid on human immunodeficiency virus promoter activity induced by 12-O-tetra decanoylphorbol-13-acetate in Jurkat T-cells.

We investigated the effect of tannic acid, a potent inhibitor of poly(ADP-ribose) glycohydrolase, on human viral gene transcription, by using chloramphenicol acetyl transferase (CAT) assay experiments transfecting Jurkat cells with CAT reporter constructs that contain the promoter region of human immunodeficiency virus (HIV) or of human T-cell leukemia virus type I (HTLV-1). The activity of HIV promoter induced by treatment with 12-O-tetradecanoylphorbol-13-acetate was suppressed by the addition of tannic acid. On the other hand, HTLV-1 promoter activity induced by the p40(tax) expression plasmid was not affected by tannic acid treatment. Deletion analysis of the HIV promoter revealed that a 30-bp element located immediately upstream of NF-kappa B motifs was responsible for the suppressive effect of tannic acid. This was supported by the observations that the negative effect of tannic acid was introduced to tannic acid-non-responsive thymidine kinase promoter by the insertion of this element 5'-upstream of the promoter.

Base Sequence↗

Kid, a novel kinesin-like DNA binding protein, is localized to chromosomes and the mitotic spindle.

Microtubule-associated motor proteins are thought to be involved in spindle formation and chromosome movements in mitosis/meiosis. We have molecularly cloned cDNAs for a gene that codes for a novel member of the kinesin family of proteins. Nucleotide sequencing reveals that the predicted gene product is a 73 kDa protein and is related to some extent to the Drosophila node gene product, which is involved in chromosomal segregation during meiosis. A sequence similar to the microtubule binding motor domain of kinesin is present in the N-terminal half of the protein, and its ability to bind to microtubules is demonstrated. Furthermore we show that its C-terminal half contains a putative nuclear localization signal similar to that of Jun and is able to bind to DNA. Accordingly, the protein was termed Kid (kinesin-like DNA binding protein). Indirect immunofluorescence studies show that Kid colocalizes with mitotic chromosomes and that it is enriched in the kinetochore at anaphase. Thus, we propose that Kid might play a role(s) in regulating the chromosomal movement along microtubules during mitosis.

Amino Acid Sequence↗

Frozen-section services by telepathology: experience of 100 cases in the San-in District, Japan.

The early experience is reported here of the use of intra-operative frozen-section service by telepathology using the integrated Service Digital Network (ISDN), a commercially available system that is being connected between the Department of Pathology of Tottori University and Matsue City Hospital, a distance of 30 km. The transfer rate is currently 64 kbit/s. The frozen-section service was conducted for a total of 117 tissue specimens (organs) from 100 patients between August 1993 and May 1995. The average time taken for examination of each specimen of frozen section was 13 min, ranging between 2 and 42 min. The average number of transmitted images was 6.2. Six cases necessitated more than 11 transmitted images to make a diagnosis, while 13 cases could be diagnosed from two images only. Correct and permissible diagnoses were obtained in 109 (93.2%) out of 117 specimens when comparing the telepathology diagnosis with that of direct microscopy. Improper or misdiagnosis was made for eight cases (specimens), which were misinterpreted as papillary carcinoma in Basedow's disease, adenoma and hyperplasia in two pheochromocytomas, solid-tubular carcinoma in phyllodes tumor, mastopathy in invasive carcinoma, metastatic carcinoma in astrocytoma, follicular lymphoma in reactive hyperplasia, and lymphadenitis in follicular lymphoma. In retrospect, diagnosis of these cases should have been deferred. From the results, it was concluded that the intraoperative frozen-section service by telepathology may be a worthwhile substitute for hospitals with limited accessibility to local pathology service, in spite of pitfalls in some cases. Well prepared, high-quality frozen section, sufficient verbal communication with surgeons, and a rather conservative attitude on the part of a well-trained pathologist seem to be the essential ingredients for reaching an accurate decision when using telepathology.

Computer Communication Networks↗

Magnesium metabolism in hyperthyroidism.

Changes in magnesium metabolism, along with those in sodium, were investigated in 17 patients with Graves' disease (14 females and 3 males, mean +/- SD, 44.8 +/- 12.2 years) and their relationship to plasma levels of thyroid hormones were assessed before and after treatment. Each patient was studied in hyperthyroid state and euthyroid state after treatment. Each patient was studied in hyperthyroid state and euthyroid state after treatment with methimazole. Treatment with methimazole increased the magnesium concentration both in erythrocytes (2.00 +/- 0.18 vs. 2.08 +/- 0.24 mmol/l cells, P < 0.05) and in serum (0.72 +/- 0.12 vs. 0.84 +/- 0.11 mmol/l, P < 0.001) but both urinary output and fractional excretion of magnesium decreased significantly (P < 0.05 and P < 0.001, respectively). The erythrocyte sodium concentration decreased with treatment (10.7 +/- 2.6 vs. 8.1 +/- 1.1 mmol/l cells, P < 0.001) but the serum sodium remained unchanged (140.9 +/- 1.9 vs. 140.9 +/- 2.1 mmol/l, NS). Urinary excretion of sodium also decreased with treatment (P < 0.05), but only changes in indices of magnesium metabolism (decrease in renal fractional excretion, rise in serum level) correlated significantly with those of the thyroid functions with treatment. These observations clearly indicate that in Graves' disease, the magnitude of magnesium metabolism alteration is closely related to the extent of the increase in thyroid hormones in plasma.

Adult↗

Risk factor analyses for macrovascular complication in nonobese NIDDM patients. Multiclinical Study for Diabetic Macroangiopathy (MSDM).

To examine the characteristic features of risk factors for macroangiopathy (MA) in nonobese Japanese NIDDM patients, 899 NIDDM patients with and without MA were registered from 40 facilities. Of these, 386 subjects were identified as having any form of MA (total MA); these included 211 with ischemic heart disease (IHD), 163 with cerebrovascular disease (CVD), and 77 with peripheral vascular disease (PVD). Univariate analyses revealed the following common risk factors for total MA, IHD, CVD, and PVD: age, hypertension, systolic blood pressure (sBP) or diastolic blood pressure (dBP), duration of diabetes, diabetic microangiopathy (retinopathy, nephropathy, and neuropathy), low HDL cholesterol level, and higher LDL cholesterol/HDL cholesterol ratio. Additional significant risk factors for specific conditions were also identified, respectively, as male sex for total MA, IHD, and PVD, smoking for IHD and PVD, and high fasting plasma glucose level for total MA and CVD. With stepwise multivariate logistic regression analysis, older age, duration of diabetes, smoking, and low LDL cholesterol/HDL cholesterol ratio were identified as significant and independent risk factors for total MA, IHD, CVD, and PVD. Other risk factors identified were high dBP for IHD, CVD, and PVD, high sBP for total MA, and low BMI for PVD. These results clearly demonstrated that duration of diabetes, smoking, hypertension, and dyslipidemia are major risk factors for MA in NIDDM patients. Since the mean BMI was similar for both groups (approximately 23 kg/m2) and there were no significant differences in immunoreactive insulin levels before and after 75-g oral glucose challenge testing, obesity and hyperinsulinism at the time of the analyses were not considered to play an important role for the pathogenesis of MA in Japanese NIDDM patients. By using the chi 2 test, cutoff points were determined for six of the most commonly measured risk factors. The cutoff point was the level beyond which a significantly higher prevalence of MA occurred. The cutoff points (rounded slightly upward in some cases) for fasting plasma glucose, sBP, dBP, serum total cholesterol level, serum triglyceride level, and BMI were 140 mg/dl, 140 mmHg, 80 mmHg, 180 mg/dl, 120 mg/dl, and 23 kg/m2, respectively. When these cutoff points were used as control criteria, the prevalence of MA was significantly lower in subjects whose risk factor measurements remained under the proposed control criteria for four or more of the six variables. In conclusion, in nonobese NIDDM patients, age, hypertension, and dyslipidemia were found to be risk factors for MA. Duration of diabetes was also demonstrated as an independent risk factor, indicating the close association of deranged glucose metabolism with the pathogenesis of MA in NIDDM patients. It seems to be crucial to control these risk factors for the prevention of MA in NIDDM patients.

Aged↗

Long-term reproducibility and usefulness of daytime recording of noninvasive 24-hour ambulatory blood pressure monitoring in borderline hypertension: a two-year follow-up study.

We investigated the long-term reproducibility of noninvasive 24-hour ambulatory blood pressure monitoring (ABPM) compared with casual blood pressure measurements in 54 individuals (47 +/- 11 years) with borderline hypertension. ABPM and casual blood pressure measurements were obtained 3 times over 2 year period. ABPM data were analyzed to determine the average 24-hour blood pressure (24-BP), the average blood pressure during the waking hours (Day-BP), and the average blood pressure from the time the subject went to bed until he awoke (Night-BP). ABPM measurements were similar for Year 1, 2, and 3 (24-BP: Year 1; 130 +/- 10/79 +/- 6 mmHg; Year 2; 130 +/- 10/79 +/- 7 mmHg; and Year 3; 130 +/- 10/78 +/- 7 mmHg). Bland-Altman analysis and standard deviation of the difference also indicated the reproducibility of 24-BP was better than casual pressure. The 24-BP was significantly correlated with both Day-BP and Night-BP for each year. Day-BP showed the stronger correlation. Our results suggest that Day-BP provides reproducible estimation in subjects with borderline hypertension.

Adult↗

[A case of abnormal hemoglobin (HbJ Cape Town) with high serum levels of HbAlc].

We describe a case of hemoglobinopathy detected on admission for examination for high blood glucose levels and abnormal liver function. In 1991, it was pointed out that he had postprandial hyperglycemia. In 1994, at age 60, he had lassitude and anorexia. He was admitted to our hospital on the suspicion of diabetes mellitus and liver disease. Glycosylated hemoglobin levels was very high, but the 75 gram oral glucose tolerance test result was within the normal range. After abstinence from alcohol, his glutamic oxaloacetic transaminase, glutamic pyruvic transaminase and gamma glutamyl traspeptidase became normal. Diabetes was excluded and abnormal hemoglobinopathy had been suspected. We analyzed his abnormal hemoglobin. In isoelectro-phoresis a fast moving variant was detected suggesting the presence of abnormal hemoglobin at the cathode. We fractionated hemolytic globin by CM-chromatography and detected an abnormal peak before the alpha chain band. Subsequently, we sequenced isolated abnormal alpha chain and detected the substitution of Ariginine for Glutamamine at position 92 (Hb J Cape Town). So far he has not demonstrated any symptoms or signs of HbJ Cape Town. Hemoglobinopathy is not uncommon in aged people.

Amino Acids↗

Glucose load and renal sodium handling in mild essential hypertension on different sodium intakes.

The aims of the present study were to investigate the effects of changes in sodium intake in patients with untreated mild essential hypertension on the hormonal (plasma renin activity and aldosterone) and renal tubular responses to short-term hyperinsulinemia as achieved by an oral glucose tolerance test (OGTT). Fourteen patients with essential hypertension (mean age, 46 years; average blood pressure (BP), 151/96 mm Hg) were studied. After a 1 week run-in period on their usual diet they entered a randomized double-blind crossover study of a week of low (10 mmol/day) vs a week of high (350 mmol/day) sodium intake. On the last day of each diet they underwent a standard 2-h OGTT. Blood and urines were taken hourly and segmental tubular sodium handling was assessed by the endogenous lithium clearance. The results demonstrate that the plasma insulin and glucose response to a short-term oral glucose load were not influenced significantly by the changes in dietary sodium intake. However, the glucose load was associated with marked renal sodium retention in the absence of any change in systemic BP. The reduction in renal sodium excretion was independent of circulating aldosterone but appeared to be due to an increase in renal distal tubular re-absorption.

Adolescent↗

Neutral endopeptidase activity in serum and cerebrospinal fluid.

We measured neutral endopeptidase (NEP) activity in serum from non-smoking healthy Japanese and in cerebrospinal fluid (CSF) from patients without neurological or inflammatory diseases. The serum NEP activity (sNEP) of 25 males and 25 females, aged 20 to 65 years, ranged from 0.003 to 1.62 pmole/min/microliter. There was no significant difference in sNEP activity between the sexes (male: 0.40 +/- 0.34 pmol/min/microliter vs female: 0.37 +/- 0.30, mean +/- S.D.). There was a significant positive correlation (p < 0.05) between sNEP and age. The NEP activity in the CSF (cNEP) ranged from 0.07 to 0.63 pmole/min/microliter. Male patients with benign prostate hypertrophy (BPH) showed cNEP activity of 0.21 +/- 0.11 pmol/min/microliter (n = 13), and female patients with myoma uteri (MU) or dysplasia of the uterus mucosa (DUM) showed activity of 0.32 +/- 0.20 (n = 5). There was no significant difference in cNEP activity between the sexes. Three patients with severe body pain showed cNEP activity of 0.21, 0.15, and 0.16 pmole/min/microliter, and these values were dissimilar from those of the BPH, MU, or DUM patients.

Age Factors↗

CD40 signaling-mediated induction of Bcl-XL, Cdk4, and Cdk6. Implication of their cooperation in selective B cell growth.

Signals sent through CD40 play crucial roles in B cell differentiation, including blocking apoptosis of germinal center B cells. In this study, using a murine B cell WEHI-231 line that undergoes apoptosis by the cross-linking of surface Ag receptors (sIgM), we have demonstrated that CD40 signalings are linked to induction of the Bcl-xL, Cdk4, and Cdk6 proteins whose expression was significantly suppressed by the apoptotic signal through sIgM. Mutational analyses of CD40 revealed that the domain of human CD40 required for blocking apoptosis of WEHI-231 cells coincides with that required for Bcl-xL induction. Signals through sIgM arrest cells in the G1 phase of the cell cycle, which is followed by apoptosis. However, while constitutive expression of Bcl-XL leads to the inhibition of apoptosis. Nevertheless, Bcl-xL fails to induce S phase entry. By CD40 signalings, both Cdk4 and Cdk6 resume their normal expression levels, which are sufficient for passing the restriction point in G1 even in the presence of the apoptotic signals mediated by sIgM. These results suggest that cooperation of Bcl-xL, Cdk4, and Cdk6 induced by CD40 signaling plays a key role in CD40-mediated selective growth of B cells.

Amino Acid Sequence↗

Molecular cloning of cDNA encoding the Xenopus homolog of mammalian RelB.

We have molecularly cloned cDNA encoding a new Rel-related protein in Xenopus laevis. Nucleotide sequencing revealed that the product is most homologous to mammalian RelB in its N-terminal region. Furthermore, the putative protein kinase A phosphorylation site (RRPS), found in most of the Rel family proteins, but replaced by QRLT in mammalian RelB, is replaced by QRIT, indicating that our cDNA most likely encodes the Xenopus homolog of mammalian RelB (XrelB). As in the case of mouse RelB, XrelB alone does not bind to DNA efficiently, while XrelB/human p50 heterodimers bind to kappa B sites and activate transcription. XrelB transcripts are present at all stages of oocyte maturation and in adult tissues examined. However, in staged embryos XrelB is undetectable from neurula to stage 28 and resumes expression at stage 47, while Xrel1/XrelA, the Xenopus homolog of p65, has been demonstrated to be expressed throughout embryogenesis. These results raise the possibility that XrelB and Xrel1/XrelA play different roles in the development of X.laevis.

Amino Acid Sequence↗

Cupric ion blocks NF kappa B activation through inhibiting the signal-induced phosphorylation of I kappa B alpha.

A transcription factor NF kappa B, which regulates expression of various cellular genes involved in immune responses and viral genes including HIV, is sequestered in the cytoplasm as a complex with an inhibitory protein I kappa B. Various extracellular signals induce phosphorylation and rapid degradation of I kappa B alpha to release NF kappa B. Cu2+ was found to inhibit the activation of NF kappa B induced by TNF-alpha, TPA, or H2O2. Deoxycholate treatment of the cytoplasmic extract prepared from cells stimulated by TNF-alpha in the presence of Cu2+ resulted in the release of NF kappa B from I kappa B alpha, indicating that Cu2+ interferes with the dissociation of the NF kappa B-I kappa B complex. Neither phosphorylation nor degradation of I kappa B alpha was observed upon TNF-alpha stimulation in the presence of Cu2+. These results indicate that Cu2+ inhibits the release of NF kappa B by blockade of a signal leading to the phosphorylation of I kappa B alpha.

Animals↗