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Biomedical subjects

S Hino

Publications and source records attributed to S Hino.

At least 37 records · Page 2Linked to original sources
PubMed2000

Nuclear translocation of TSC-22 (TGF-beta-stimulated clone-22) concomitant with apoptosis: TSC-22 as a putative transcriptional regulator.

We examined the alteration of the subcellular localization of TSC-22 (TGF-beta-stimulated clone-22) after induction of apoptosis and the transcription-regulatory activity of TSC-22. In the living cells, TSC-22-green fluorescent protein (GFP) fusion protein was clearly localized to the cytoplasm, however, in the apoptotic cells, the TSC-22-GFP fusion protein was translocated from the cytoplasm to the nucleus. TSC-22 fused to GAL4-DNA binding domain (GAL4BD) did not show the transcriptional activity on the reporter genes in yeast and in HSG (salivary gland cancer cells) and Hela. However, in CHO cells, TSC-22-GAL4BD fusion protein strongly activated the reporter gene. The transcriptional activity of the leucine zipper structure of TSC-22 is greater than that of the full-length TSC-22. These findings suggest that after receiving the apoptotic stimuli, TSC-22 translocates from the cytoplasm to the nucleus and shows the transcription-regulatory activity.

Animals↗
PubMed2000

A novel beta-catenin-binding protein inhibits beta-catenin-dependent Tcf activation and axis formation.

beta-Catenin is efficiently phosphorylated by glycogen synthase kinase-3beta in the Axin complex in the cytoplasm, resulting in the down-regulation. In response to Wnt, beta-catenin is stabilized and translocated into the nucleus where it stimulates gene expression through Tcf/Lef. Here we report a novel protein, designated Duplin (for axis duplication inhibitor), which negatively regulates the function of beta-catenin in the nucleus. Duplin was located in the nucleus. Duplin bound directly to the Armadillo repeats of beta-catenin, thereby inhibiting the binding of Tcf to beta-catenin. It did not affect the stability of beta-catenin but inhibited Wnt- or beta-catenin-dependent Tcf activation. Furthermore, expression of Duplin in Xenopus embryos inhibited the axis formation and beta-catenin-dependent axis duplication, and prevented the beta-catenin's ability to rescue ventralizing phenotypes induced by ultraviolet light irradiation. Thus, Duplin is a nuclear protein that inhibits beta-catenin signaling.

Amino Acid Sequence↗
PubMed2000

Prospective reevaluation of risk factors in mother-to-child transmission of hepatitis C virus: high virus load, vaginal delivery, and negative anti-NS4 antibody.

Of 21,791 pregnant women screened in Tottori Prefecture, Japan, 127 (0.58%) were positive for anti-hepatitis C virus (HCV) antibody and 84 (0.39%) were positive for HCV RNA. Of 84 children followed up for at least 6 months, 7 (8%) were infected. All of them were born to 26 mothers with a high virus load (HVL; >/=2.5x106 RNA copies/mL [27%]), compared with 0 of 58 children born to non-HVL mothers (P<.001). Because all the infected children were vaginally delivered, the infection rate among 16 vaginally delivered children born to the HVL mothers was as high as 44%. The prevalence of anti-NS4 antibody in the mothers with an infectious HVL was significantly lower than that in the mothers with a noninfectious HVL (P=.048). Analysis of our results suggests that maternal HVL, vaginal delivery, and negative anti-NS4 antibody are significant risk factors for the mother-to-child transmission of HCV.

Delivery, Obstetric↗
PubMed2000

Molecular cloning, expression, and chromosomal localization of a human tubulointerstitial nephritis antigen.

Tubulointerstitial nephritis antigen (TIN-ag) is an extracellular matrix basement protein which was originally identified as a target antigen involved in anti-tubular basement membrane (TBM) antibody-mediated interstitial nephritis (TIN). Further investigations elucidated that TIN-ag plays a role in renal tubulogenesis and that TIN-ag is defected in hereditary tubulointerstitial disorder such as juvenile nephronophthisis. We previously isolated and characterized 54 kDa glycoprotein as TIN-ag. cDNA encoding rabbit and mouse TIN-ag has recently been identified. In the present study, the cDNA of the human homologue of TIN-ag was cloned and its nucleotide sequence was determined (Accession No. AB022277; the DDBJ nucleotide sequence database). Deduced amino acid sequence (476 aa) exhibited the presence of a signal peptide (1-18 aa), cysteine residues termed follistatin module, six potential glycosylation sites, and an ATP/GTP-binding site. Homology search revealed approximately 85% homology with both rabbit and mouse TIN-ag, and also some ( approximately 40%) similarity with C. elegans. Human TIN-ag contained a sequence similar to several classes of extracellular matrix molecules in amino terminal region and to cathepsin family of cysteine proteinases in the carboxyl terminal region. Northern blot analysis revealed exclusive expression of this molecule in human adult and fetal kidney tissues. Using a monoclonal antibody recognizing human TIN-ag, protein expression ( approximately 50 kDa) was identified in cultured COS-1 cells transfected with human TIN-ag cDNA. The human TIN-ag was mapped to chromosome 6p11.2-12 by fluorescence in situ hybridization. These results may provide further evidence for understanding TIN-ag molecule and clues for gene analysis of juvenile nephronophthisis.

Adult↗
PubMed2000

Clinical and radiological features in four adolescents with nutcracker syndrome.

We describe four adolescents with the nutcracker syndrome. In three patients, the nutcracker syndrome was detected through mass urinary screening; the other patient was diagnosed after a sudden onset of dark urine. All patients underwent magnetic resonance angiography (MRA) for diagnosis of the nutcracker syndrome, which revealed dilatation of the left renal vein ranging between 7.4 and 13 mm at the hilar portion. A renal biopsy, performed in three patients, showed no remarkable abnormalities in the glomerulus or tubulointerstitial tissue. The patients complained of physical discomfort, including headache, abdominal pain, fainting, and tachycardia mimicking clinical symptoms of an orthostatic disturbance. However, no chronic systemic diseases were detected in any of the patients after repeated laboratory examinations. An orthostatic disturbance preceded diagnosis in three patients. This report indicates that the nutcracker syndrome may cause serious physical ailments that clinically mimic an orthostatic disturbance. It may be important to identify the nutcracker syndrome among children who manifest non-specific physical complaints. MRA could be a safe and reliable method for diagnosing the nutcracker syndrome.

Abdominal Pain↗
PubMed2000

High frequency of postnatal transmission of TT virus in infancy.

DNA of TT virus (TTV), a novel human circovirus, was tested for in 116 mother-infant pairs who had participated in the adult T-cell leukemia prevention program (APP) in Nagasaki, Japan, and refrained from breast-feeding. By polymerase chain reaction with Okamoto's seminested primers, 36 of the 115 (31%) mothers were positive. At the age of 6-8 months, 7 of 29 (24%) and 6 of 72 (8%) infants born to infected and uninfected mothers were positive, respectively (P = 0.047; RR, 2.90). Maternal TTV DNA load did not correlate with infantile infections. Since 99 of 100 (99%) cord blood samples were negative and all the mothers refrained from breast-feeding, the infantile TTV transmission would not be intrauterine or milk-borne. Between 6-8 and 12-21 months of age, 4 of 12 (33%) and 5 of 22 (23%) children born to infected and uninfected mothers turned positive, respectively (NS). At 12-21 months of age, 8 of 21 (38%) and 12 of 32 (38%) children born to infected and uninfected mothers were positive, respectively (NS). These results indicate that the TTV infection prevails in children at a frequency comparative to that in their mothers within the first 2 years of life, regardless of the maternal TTV status.

Adult↗
PubMed2000

Over-expression of TSC-22 (TGF-beta stimulated clone-22) markedly enhances 5-fluorouracil-induced apoptosis in a human salivary gland cancer cell line.

We have recently isolated TSC-22 (transforming growth factor-beta-stimulated clone-22) cDNA as an anticancer, drug-inducible (with vesnarinone) gene in a human salivary gland cancer cell line, TYS. We have also reported that TSC-22 negatively regulates the growth of TYS cells and that down-regulation of TSC-22 in TYS cells plays a major role in salivary gland tumorigenesis (Nakashiro et al, 1998). In this study, we transfected TYS cells with an expression vector encoding the TSC-22-GFP (green fluorescent protein) fusion protein, and we established TSC-22-GFP-expressing TYS cell clones. Next, we examined (a) the subcellular localization of the fusion protein, (b) the sensitivity of the transfectants to several anticancer drugs (5-fluorouracil, cis-diaminedichloroplatinum, peplomycin), and (c) induction of apoptotic cell death in the transfectants by 5-fluorouracil treatment. The TSC-22-GFP fusion protein was clearly localized to the cytoplasm, but not to the nucleus. Over-expression of the TSC-22-GFP fusion protein did not affect cell growth, but significantly increased the sensitivity of the cells to the anticancer drugs (p < 0.01; one-way ANOVA). Furthermore, over-expression of the TSC-22-GFP fusion protein markedly enhanced 5-fluorouracil-induced apoptosis. These findings suggest that over-expression of TSC-22-GFP protein in TYS cells enhances the chemosensitivity of the cells via induction of apoptosis.

Antineoplastic Agents↗
PubMed2000

Three spliced mRNAs of TT virus transcribed from a plasmid containing the entire genome in COS1 cells.

A permuted whole-genome construct of a TT virus (TTV), named VT416, had 3,852 nucleotides (nt) 98.2% similar to the prototype TA278 genome. To allow the transcription of TTV from the internal promoter, pBK*VT416(1.3G), carrying 1.3 units of VT416, was constructed. The poly(A)(+) RNAs expressed in COS1 cells 48 h posttransfection contained three TTV mRNA species 3.0, 1.2, and 1.0 kb in length, which were recovered in the 13 DNA clones from a lambda phage cDNA library. These mRNAs in the antigenomic orientation possessed in common the 3' terminus downstream of a poly(A) signal (A(3073)ATAAA) and the 5' terminus downstream of a cap site (C(98)ACTTC). A common splicing to join nt 185 with nt 277 was detected in all mRNAs. The coding region of the largest open reading frame (ORF) was maintained in 3.0-kb mRNA, because this splicing was located upstream of its initiation codon (A(589)TG). The second splicing was detected in 1.2-kb mRNA to join nt 711 with nt 2374 and in 1.0-kb mRNA to bind nt 711 to nt 2567. They linked a proposed ORF2 to another ORF for creating new ORFs over nt 2374 to 2872 in frame 2 and nt 2567 to 3074 in frame 3. The donor and acceptor sites of all three splicings matched the consensus sequence and were conserved in most of the 16 TTVs of distinct genotypes retrieved from the database. The observed transcription profile is unique to TTV among known members in the family Circoviridae.

Animals↗
PubMed2000

Evolution in the hypervariable region of hepatitis C virus in infants after vertical transmission.

To elucidate the clonal evolution of hepatitis C virus (HCV) during mother-to-infant transmission, we prospectively analyzed HCV clones of the hypervariable region in four HCV RNA-positive infants and compared them with those of the mother. Cord blood samples from three of the four infants were positive for the HCV RNA (< or =10(3) copies/mL), and all of the four infants had the HCV RNA titer of >10(6) copies/mL within 2 mo after birth. The hypervariable region clones detected in the infants were closely related to those in the respective mothers. The results suggest the perinatal transmission of HCV. The hypervariable region clones transmitted to infants were not a single selected clone or minor clones in the mother. None of the clones specific to the low-density fraction in the mother was transmitted to the infants. Moreover, the proportion of HCV in the low-density fraction was minimal in the first few months of life, but increased several months after birth in association with the elevation of alanine aminotransferase. These results suggest that the increase of HCV in the low-density fraction reflect the evolution of immune response in infants. We also demonstrated that the emergence of quasispecies in infants precedes the infantile antibody response.

Aging↗
PubMed1999

Biochemical characterization of various catalytic complexes of the brain platelet-activating factor acetylhydrolase.

Brain intracellular platelet-activating factor acetylhydrolase (PAF-AH) isoform I is a member of a family of complex enzymes composed of mutually homologous alpha(1) and alpha(2) subunits, both of which account for catalytic activity, and the beta subunit. We previously demonstrated that the expression of one catalytic subunit, alpha(1), is developmentally regulated, resulting in a switching of the catalytic complex from alpha(1)/alpha(2) to alpha(2)/alpha(2) during brain development (Manya, H., Aoki, J., Watanabe, M., Adachi, T., Asou, H., Inoue, Y., Arai, H., and Inoue, K. (1998) J. Biol. Chem. 273, 18567-18572). In this study, we explored the biochemical differences in three possible catalytic dimers, alpha(1)/alpha(1), alpha(1)/alpha(2), and alpha(2)/alpha(2). The alpha(2)/alpha(2) homodimer exhibited different substrate specificity from the alpha(1)/alpha(1) homodimer and the alpha(1)/alpha(2) heterodimer, both of which showed similar substrate specificity. The alpha(2)/alpha(2) homodimer hydrolyzed PAF and 1-O-alkyl-2-acetyl-sn-glycero-3-phosphorylethanolamine (AAGPE) most efficiently among 1-O-alkyl-2-acetyl-phospholipids. In contrast, both alpha(1)/alpha(1) and alpha(1)/alpha(2) hydrolyzed 1-O-alkyl-2-acetyl-sn-glycero-3-phosphoric acid more efficiently than PAF. AAGPE was the poorest substrate for these enzymes. The beta subunit bound to all three catalytic dimers but modulated the enzyme activity in a catalytic dimer composition-dependent manner. The beta subunit strongly accelerated the enzyme activity of the alpha(2)/alpha(2) homodimer but rather suppressed the activity of the alpha(1)/alpha(1) homodimer and had little effect on that of the alpha(1)/alpha(2) heterodimer. The (His(149) to Arg) mutant beta, which has been recently identified in isolated lissencephaly sequence patients, lost the ability to either associate with the catalytic complexes or modulate their enzyme activity. The enzyme activity of PAF-AH isoform I may be regulated in multiple ways by switching the composition of the catalytic subunit and by manipulating the beta subunit.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗
PubMed1999

Heparin-binding EGF-like growth factor is expressed by mesangial cells and is involved in mesangial proliferation in glomerulonephritis.

Heparin-binding epidermal growth factor-like growth factor (HB-EGF), a new member of the EGF family, is mitogenic for several types of cells, through binding to cell surface heparan sulphate proteoglycans. This study has attempted to delineate HB-EGF expression by mesangial cells and to identify its role in experimental and human glomerulonephritis. Rat mesangial cells, cultured in the presence of phorbol acetate, hydrogen peroxide, interleukin-1beta, and tumour necrosis factor-alpha, expressed HB-EGF mRNA. Recombinant HB-EGF stimulated rat mesangial cells to proliferate and to express types I and III collagen. In the rat anti-Thy-1.1 nephritis, glomerular HB-EGF mRNA was up-regulated and peaked at days 5-7; its expression at the protein level in the glomerulus was prominent at days 5-10. By immunofluorescence, HB-EGF was positive predominantly in the mesangial area of renal tissues from 23 of 45 patients with various types of human glomerulonephritis, showing a significant correlation with the grade of mesangial proliferation; there was no staining in tissues from patients with minimal change nephrotic syndrome and normal kidney tissues. These data provide the evidence that HB-EGF is synthesized and expressed by mesangial cells and stimulates mesangial cell proliferation and collagen synthesis in vitro. HB-EGF is a potential mediator in mesangial cell proliferation and matrix expansion in experimental and human glomerulonephritis.

Animals↗
PubMed1999

Course and outcome of tubulointerstitial nephritis and uveitis syndrome.

We report here the clinical features and outcomes of 10 patients, aged 11 to 21 years (median, 13.0), with idiopathic tubulointerstitial nephritis (TIN) and uveitis syndrome (TINU syndrome). The initial symptoms were visual impairment in 7 patients and prolonged fever, anemia, or asthenia in 4 patients. An increase in urinary beta(2)-microglobulin was noticed at the initial checkup in all patients, including 2 patients who showed the normal ranges of 24-hour protein excretion. Creatinine clearance was decreased in 8 patients. TIN was found simultaneously with ocular symptoms in 7 patients and preceded these symptoms in the remaining 3 patients. Percutaneous renal biopsy indicated tubulointerstitial lesions in varying degrees. The histological grade of TIN was correlated with urinary beta(2)-microglobulin levels. Systemic steroid therapy was performed in 7 patients because of the progression of uveitis. The 10 patients were followed-up for 16 to 94 months (median, 31.0 months). In all patients, creatinine clearance recovered to the normal ranges (>/=70 mL/min/1.73 m(2)) mostly within 1 year. Urinary beta(2)-microglobulin excretion gradually declined but was slightly elevated in 4 patients at the latest checkup. Uveitis recurred in all 10 patients, which did not affect the renal status. Our findings indicate that early referral of patients from ophthalmologists and determination of beta(2)-microglobulin in the urine is helpful for the early discovery of TINU syndrome. In children and adolescents with this syndrome, TIN spontaneously resolves and its long-term prognosis is good, but uveitis often relapses. Systemic steroids may be required for uveitis, but not for TIN.

Adolescent↗
PubMed1999

Haematogenous cytokeratin 20 mRNA as a predictive marker for recurrence in oral cancer patients.

We examined the expression of cytokeratin 20 (CK20) mRNA in the peripheral blood of oral squamous cell carcinoma (SCC) patients by reverse transcriptase polymerase chain reaction (RT-PCR). Eleven out of 12 oral SCC patients showed positive RT-PCR results. However, there is no clear relationship between the haematogenous CK20 mRNA and the metastasis. After initial treatment, all of the tumour-free survivors tested showed negative RT-PCR results. CK20 mRNA in peripheral blood can be used as a marker for tumour recurrence but not not for metastasis in oral SCC patients.

Biomarkers, Tumor↗
PubMed1999

Shift in the buoyant density of hepatitis C virus particles in infants infected by mother-to-infant transmission.

BACKGROUND: Hepatitis C virus (HCV) particles in sera can be divided into two classes: low-density free particles and high-density immune complex particles. Previous studies have revealed that the clinical progression of HCV infection is closely associated with the occurrence of the former class, rather than the latter, in an experimental chimpanzee model and in HCV-infected adult cases. METHODS: To verify this concept in infantile cases, we prospectively analysed HCV particle populations, fractionated according to buoyant density, in serum samples from five infants infected by mother-to-infant transmission. RESULTS: In all five cases, HCV particles were predominantly high density at the age of one month. In four of five cases, low-density HCV particles became predominant in association with a decrease in maternally transmitted antibody levels. In one case, in which high serum levels of alanine aminotransferase persisted, low-density particles were predominant between the ages of 3 and 9 months, in three consecutive samples. In other cases, in which infants were asymptomatic or had transient hepatitis, low-density HCV particles were predominant at only one sampling point or not at all throughout the follow-up period. CONCLUSIONS: Maternal antibody transmitted via the placenta reacts with the HCV particles in infants infected through vertical transmission. A decrease in maternal antibody levels results in an increase in low-density free virions. It is suggested that low-density particles play an important role in liver inflammation.

Centrifugation, Density Gradient↗
PubMed1999

Coexpression of CD9 augments the ability of membrane-bound heparin-binding epidermal growth factor-like growth factor (proHB-EGF) to preserve renal epithelial cell viability.

BACKGROUND: Transfection of renal epithelial cells (NRK 52E) with membrane-associated heparin-binding epidermal growth factor-like growth factor (proHB-EGF) increased renal epithelial cell survival by promoting cell-cell and cell-extracellular matrix interactions. ProHB-EGF has been shown to form a complex in the plasma membrane with the tetraspanin CD9, an interaction that significantly increases the effectiveness of proHB-EGF as a juxtacrine mitogenic agent. METHODS: We examined whether the coexpression of proHB-EGF and CD9 would increase renal epithelial cell survival. CD9 was stably transfected into NRK 52E cells, either alone (NRKCD9) or together with proHB-EGF (NRKboth). RESULTS: Juxtacrine mitogenic activity of NRKCD9 was no different than in cells transfected with vector alone (NRKvector), but was increased by NRKboth; juxtacrine mitogenic activity by NRKboth was twofold greater than when proHB-EGF was transfected alone (NRKproHB-EGF). When grown in 10% fetal calf serum, growth rates were similar among all transfectants. However, in 1% fetal calf serum, NRKproHB-EGF grew 50% faster than NRKvector or NRKCD9, and NRKboth grew 20% to 50% faster than NRKproHB-EGF at one, two, and three days of culture. NRKproHB-EGF attachment to plastic substratum at one, two, and three hours was 250% greater than that of NRKvector, and NRKboth was 20% to 30% greater than that of NRKproHB-EGF. Coating plates with either poly 2-hydroxyethyl methacrylate or the GRGDTP peptide prevented normal cell-extracellular matrix attachment, and NRKvector or NRKCD9 failed to attach or form cell-cell attachments. NRKproHB-EGF exhibited 300% and NRKboth exhibited 600% greater cell viability under these conditions. Expression of type I and type III collagen mRNA was enhanced similarly in NRKproHB-EGF and NRKboth, but the expression of beta1 integrin was up-regulated only in NRKboth. CONCLUSIONS: Coexpression of proHB-EGF and CD9 may render the renal epithelial cells more resistant to disruption of cell-cell and cell-matrix interactions and could accelerate the re-establishment of these attachments.

Animals↗
PubMed1999

Identification of a novel GC-rich 113-nucleotide region to complete the circular, single-stranded DNA genome of TT virus, the first human circovirus.

The sequence data (H. Okamoto et al., Hepatol. Res. 10:1-16, 1998) of a newly discovered single-stranded DNA virus, TT virus (TTV), showed that it did not have the terminal structure typical of a parvovirus. Elucidation of the complete genome structure was necessary to understand the nature of TTV. We obtained a 1.0-kb amplified product from serum samples of four TTV carriers by an inverted, nested long PCR targeted for nucleotides (nt) 3025 to 3739 and 1 to 216 of TTV. The sequence of a clone obtained from serum sample TA278 was compared with those registered in GenBank. The complete circular TTV genome contained a novel sequence of 113 nt (nt 3740 to 3852 [=0]) in between the known 3'- and 5'-end arms, forming a 117-nt GC-rich stretch (GC content, 90.6% at nt 3736 to 3852). We found a 36-nt stretch (nt 3816 to 3851) with an 80.6% similarity to chicken anemia virus (CAV) (nt 2237 to 2272 of M55918), a vertebrate circovirus. A putative SP-1 site was located at nt 3834 to 3839, followed by a TATA box at nt 85 to 90, the first initiation codon of a putative VP2 at nt 107 to 109, the termination codon of a putative VP1 at nt 2899 to 2901, and a poly(A) signal at nt 3073 to 3078. The arrangement was similar to that of CAV. Furthermore, several AP-2 and ATF/CREB binding sites and an NF-kappaB site were arranged around the GC-rich region in both TTV and CAV. The data suggested that TTV is circular and similar to CAV in its genomic organization, implying that TTV is the first human circovirus.

Base Sequence↗
PubMed1999

DIX domains of Dvl and axin are necessary for protein interactions and their ability to regulate beta-catenin stability.

The N-terminal region of Dvl-1 (a mammalian Dishevelled homolog) shares 37% identity with the C-terminal region of Axin, and this related region is named the DIX domain. The functions of the DIX domains of Dvl-1 and Axin were investigated. By yeast two-hybrid screening, the DIX domain of Dvl-1 was found to interact with Dvl-3, a second mammalian Dishevelled relative. The DIX domains of Dvl-1 and Dvl-3 directly bound one another. Furthermore, Dvl-1 formed a homo-oligomer. Axin also formed a homo-oligomer, and its DIX domain was necessary. The N-terminal region of Dvl-1, including its DIX domain, bound to Axin directly. Dvl-1 inhibited Axin-promoted glycogen synthase kinase 3beta-dependent phosphorylation of beta-catenin, and the DIX domain of Dvl-1 was required for this inhibitory activity. Expression of Dvl-1 in L cells induced the nuclear accumulation of beta-catenin, and deletion of the DIX domain abolished this activity. Although expression of Axin in SW480 cells caused the degradation of beta-catenin and reduced the cell growth rate, expression of an Axin mutant that lacks the DIX domain did not affect the level of beta-catenin or the growth rate. These results indicate that the DIX domains of Dvl-1 and Axin are important for protein-protein interactions and that they are necessary for the ability of Dvl-1 and Axin to regulate the stability of beta-catenin.

Adaptor Proteins, Signal Transducing↗