Biomedical subjects

J Nishida

Publications and source records attributed to J Nishida.

At least 73 records · Page 4Linked to original sources

PubMed1995

Dual functions of the AML1/Evi-1 chimeric protein in the mechanism of leukemogenesis in t(3;21) leukemias.

The chromosomal translocation t(3;21)(q26;q22), which is found in blastic crisis in chronic myelogenous leukemias and myelodysplastic syndrome-derived leukemias, produces AML1/Evi-1 chimeric transcription factor and is thought to play important roles in acute leukemic transformation of hemopoietic stem cells. We report here the functional analyses of AML1/Evi-1. It was revealed that AML1/Evi-1 itself does not alter the transactivation level through mouse polyomavirus enhancer-binding protein 2 (PEBP2; PEA2) sites (binding site of AML1) but dominantly suppresses the transactivation by intact AML1, which is assumed to be a stimulator of myeloid cell differentiation. DNA-binding competition is a putative mechanism of such dominant negative effects of AML1/Evi-1 because it binds to PEBP2 sites with higher affinity than AML1 does. Furthermore, AML1/Evi-1 stimulated c-fos promoter transactivation and increased AP-1 activity, as Evi-1 (which is not normally expressed in hemopoietic cells) did. Experiments using deletion mutants of AML1/Evi-1 showed that these two functions are mutually independent because the dominant negative effects on intact AML1 and the stimulation of AP-1 activity are dependent on the runt domain (DNA-binding domain of AML1) and the zinc finger domain near the C terminus, respectively. Furthermore, we showed that AML1/Evi-1 blocks granulocytic differentiation, otherwise induced by granulocyte colony-stimulating factor, of 32Dcl3 myeloid cells. It was also suggested that both AML1-derived and Evi-1-derived portions of the fusion protein play crucial roles in this differentiation block. We conclude that the leukemic cell transformation in t(3;21) leukemias is probably caused by these dual functions of AML1/Evi-1 chimeric protein.

3T3 Cells↗

PubMed1995

Of the GATA-binding proteins, only GATA-4 selectively regulates the human interleukin-5 gene promoter in interleukin-5-producing cells which express multiple GATA-binding proteins.

Interleukin-5 (IL-5) is produced by T lymphocytes and known to support B-cell growth and eosinophilic differentiation of the progenitor cells. Using ATL-16T cells which express IL-5 mRNA, we have identified a region within the human IL-5 gene promoter that regulates IL-5 gene transcription. This cis-acting sequence contains the core binding motif, (A/T)GATA(A/G), for GATA-binding family proteins and thus suggests the involvement of this family members. In this report, we describe the cloning of human GATA-4 (hGATA-4) and show that hGATA-4 selectively interacts with the -70 GATA site within the IL-5 proximal promoter region. By promoter deletion and mutation analyses, we established this region as a positive regulatory element. Cotransfection experiments revealed that both hGATA-4 and phorbol-12-myristate-13-acetate (PMA)-A23187 stimulation are necessary for IL-5 promoter activation. The requirement for another regulatory element called CLE0, which lies downstream of the -70 GATA site, was also demonstrated. ATL-16T cells express mRNAs of three GATA-binding proteins, hGATA-2, hGATA-3, and hGATA-4, and each of them has a potential to bind to the consensus (A/T)GATA(G/A) motif. However, using ATL-16T nuclear extract, we demonstrated that GATA-4 is the only GATA-binding protein that forms a specific DNA-protein complex with the -70 GATA site. An electrophoretic mobility shift assay with extracts of COS cells expressing GATA-binding proteins showed that GATA-4 has the highest binding affinity for the -70 GATA site among the three GATA-binding proteins. When the transactivation abilities were compared among the three, GATA-4 showed the highest activity. These results demonstrate the selective role of GATA-4 in the transcriptional regulation of the IL-5 gene in a circumstance where multiple members of the GATA-binding proteins are expressed.

Amino Acid Sequence↗

PubMed1995

Cortical defect of the distal fibula: variant of ossification.

PURPOSE: To elucidate the nature of a normally occurring cortical defect of the distal fibula. MATERIALS AND METHODS: In patients with sprain and nonspecific ankle pain during a 2-year period, the authors reviewed ankle radiographs, computed tomographic (CT) scans, and magnetic resonance (MR) images. Cases were added from our file. Dried skeletons and cadavers were evaluated with radiography for the presence of this cortical defect. RESULTS: Fifteen (1.8%) of 847 radiographs in 739 patients (male, 377; female, 362; age range, 15-84 years) showed a small cortical defect in the anterior aspect at the level of the distal tibiofibular joint. The age range of the subjects with the defect (male, four; female, 11) was 16-66 years. MR imaging in two patients showed a small low-signal-intensity area at the insertion site of the anterior tibiofibular ligament. Evaluation of 148 skeletons (75 subjects) revealed similar cortical defect in two cases (1.4%). CONCLUSION: The cortical defect of the distal fibula, at the insertion site of the anterior tibiofibular ligament, has no clinical significance and should not be confused with neoplasm.

Adolescent↗

PubMed1995

Desmoplastic fibroma. Aggressive curettage as a surgical alternative for treatment.

In this article, the authors present 5 patients with desmoplastic fibroma and review the literature. Four patients had aggressive curettage with bone graft, and 1 had aggressive curettage alone. Although the literature reports that many patients have recurrence after curettage, there have been no recurrences in these 5 patients during followup periods ranging from 5 years 6 months to 9 years. Although wide excision has been recommended in the literature, treatment with aggressive curettage achieved clinical and radiographic control of the lesions for at least an intermediate duration of followup.

Adolescent↗

PubMed1994

Characterization, partial purification, and peptide sequencing of p130,the main phosphoprotein associated with v-Crk oncoprotein.

The transforming gene v-crk found in CT10 and ASV-1 avian sarcoma viruses induces marked phosphorylation of several proteins in cells expressing p47v-crk (v-Crk). In this work, the main tyrosine-phosphorylated proteins in ASV-1-infected chicken cells and v-crk-transfected rat cells were characterized biochemically. Both these proteins have a molecular mass of about 130 kDa and are tightly associated with v-Crk in vivo. Two-dimensional gel electrophoresis revealed that they are both essentially single proteins (p130) with modifications that result in a broad spot in an acidic region. The broad band of semi-purified p130 became sharp at an elevated position in the gel upon treatment with orthovanadate in vivo or with c-Src kinase produced using a baculovirus vector in vitro, whereas it shifted at a lower position upon treatment with alkaline phosphatase in vitro. These results suggest multiple phosphorylation states of p130, which result in a broad band of p130. Two procedures of immunoaffinity purification were used to purify p130 from 3Y1 cells transfected with v-crk. Approximately 30 pmol of purified p130 was obtained in an immobilized form on a filter starting from 3 x 10(10) cells. Peptide mapping of p130 digested in situ by peptidase revealed that the purity and quantity of the final material were enough for peptide sequencing. Several stretches of partial amino acid sequences were determined, and they indicated that p130 is a novel protein.

Amino Acid Sequence↗

PubMed1994

Molecular cloning, characterization, and chromosomal localization of a novel protein-tyrosine phosphatase, HPTP eta.

Protein-tyrosine phosphatases (PTPases) are considered to play an important role in signal transduction. We previously identified partial sequences of three novel PTPases in a human leukemic cell line. F-36P. We describe here cloning, characterization, and chromosomal localization of one of the newly identified PTPases, termed as HPTP eta (human protein-tyrosine phosphatase eta). The deduced amino acid sequence was composed of an extracellular region homologous to fibronectin type III repeats, a transmembrane region, and a cytoplasmic region containing a single PTPase-like domain. Based on its primary structure, this clone belongs to type-III receptor-type PTPases. The PTPase-like domain showed PTPase activity when expressed in Escherichia coli. Antibody against the extracellular region detected a protein of 220 to 250 kD in human hematopoietic cell lines expressing HPTP eta mRNA. The antibody also recognized a protein of approximately the same molecular weight in COS cells transfected with HPTP eta cDNA, indicating that the antibody specifically recognized HPTP eta gene product and that the cloned cDNA contained full-length coding region. The chromosomal localization determined by fluorescence in situ hybridization showed that the HPTP eta gene was located at chromosome 11p11.2 on the short arm of chromosome 11, which is frequently lost or deleted in human carcinomas.

Amino Acid Sequence↗

PubMed1994

Molecular cloning and characterization of a cDNA for bovine phospholipase C-alpha: proposal of redesignation of phospholipase C-alpha.

We have isolated bovine phospholipase C (PLC)-alpha cDNA from bovine thymus. Sequence analysis showed that PLC-alpha is highly conserved among rat, mouse, and calf and that it has two Trp-Cys-Gly-His-Cys-Lys motifs completely conserved in the mammals. Southern blot analysis revealed that bovine PLC-alpha is derived from a single gene. When PLC-alpha cDNA was stably transfected in NIH3T3 cells, there was no increase in PLC activity. PLC-alpha is supposed to be a member not of PLC superfamily but of Trp-Cys-Gly-His-Cys-Lys motif-containing proteins consisting of protein disulfide isomerase, P5, ERp72, and thioredoxin. PLC-alpha should be redesignated ERp57 (ER-resided p57).

3T3 Cells↗

PubMed1994

Evi-1 raises AP-1 activity and stimulates c-fos promoter transactivation with dependence on the second zinc finger domain.

Evi-1 is a gene, encoding a zinc finger protein, associated with a common viral integration site in murine leukemias. It is suggested that Evi-1 plays important roles in embryogenesis and transformation of myeloid cells. To elucidate mechanisms by which Evi-1 induces such biological effects, we analyzed the relationship between Evi-1 and AP-1 which could regulate cellular proliferation and differentiation. When Evi-1 was expressed, transactivation through a 12-O-tetradecanoylphorbol 13-acetate-responsive element was observed in NIH3T3 and P19 cells. Evi-1-transfected P19 cells showed some differentiated phenotypes and increased expression of endogenous c-Jun and c-Fos. These results indicate that Evi-1 raises AP-1 activity. Evi-1 caused stimulation of the c-fos promoter transactivation, which seems to be a main mechanism of AP-1 activation, through at least two portions of the promoter. Evi-1 has the first zinc finger domain at the N terminus and the second zinc finger domain near the C-terminus. We constructed deletion mutants of Evi-1 and investigated the functions of these domains. It was shown that the second zinc finger domain is essential for the activation of AP-1 and transactivation of the c-fos promoter.

3T3 Cells↗

PubMed1994

Magnetic resonance imaging of pseudomalignant osseous tumor of the hand.

Noninfectious, nonneoplastic reactive processes of the hand, such as myositis ossificans circumscripta, pseudomalignant osseous tumor of soft tissue, and florid reactive periostitis, appear similar radiologically and histologically and are often difficult to differentiate. Magnetic resonance (MR) findings in two such lesions are reported. The extensive reactive change in the extraosseous soft tissue and the bone marrow and the relatively small extent of ossification may be characteristic. Although low-grade infection and small osseous neoplasms with reactive changes, such as osteoid osteoma, may still remain possible causes, MR imaging provides essential evidence for including noninfective, nonneoplastic reactive processes of uncertain cause in the list of differential diagnoses.

Adult↗

PubMed1994

Fluid-fluid levels in cavernous hemangioma of soft tissue.

Five cases of cavernous hemangioma with fluid-fluid levels on magnetic resonance imaging and/or computed tomography are reported. The signal characteristics were those of blood and histological analysis of the fluid-fluid levels showed that they were blood-filled cavities in the tumor. Although this finding itself is not specific, it may help in confirming the diagnosis of cavernous hemangioma.

Biomarkers↗

PubMed1994

Ethanol exacerbates hepatic microvascular dysfunction, endotoxemia, and lethality in septic mice.

The effect of acute ethanol administration on the hepatic microvascular responses to sepsis was studied. Polymicrobial sepsis was induced 30 min after mice had received ethanol (1 g/kg b.w.) or isocaloric maltose-dextrin by gastric gavage. Lethality within 24 h was 91.7% in the ethanol-treated animals and 40.0% in septic controls. Endotoxin levels in ethanol treated animals were 107 pg/ml at 6 hr and 1205 pg/ml at 12 h, compared with 32 pg/ml and 104 pg/ml, respectively in the controls. In vivo microscopy revealed that at 3 h in the ethanol treated septic animals, Kupffer cell phagocytic activity was increased by 41%, whereas the number of sinusoids containing blood flow were reduced by 34% concomitant with a 144% increase in the adherence of leukocytes to the sinusoidal walls when compared with the septic controls. By 6 h, however, Kupffer cell phagocytic activity was reduced by 48% in the ethanol treated animals; this was accompanied by a further deterioration in sinusoidal blood flow. Thus, a small, acute dose of ethanol causes significant impairment of the hepatic microcirculation followed by suppression of Kupffer cell activity. This results in exacerbation of endotoxemia and lethality during polymicrobial sepsis.

Animals↗

PubMed1994

Molecular cloning of a novel human cDNA encoding a zinc finger protein that binds to the interleukin-3 promoter.

The CT/GC-rich region (-76 to -47) is one transcriptional regulatory region of the interleukin-3 (IL-3) gene which confers basic transcriptional activity and responds to trans-activation by human T-cell leukemia virus type I-encoded Tax. We isolated three types of cDNAs encoding Cys2/His2-type zinc finger proteins that bind to this region. Two were identical to known transcription factors, EGR1 and EGR2, and the other clone, named DB1, encoded a novel protein of 516 amino acids with six zinc finger motifs. DB1 mRNA was present in human tissues, ubiquitously. Two constitutive transcripts of 4.0 and 4.8 kb in length were present in Jurkat cells. Electrophoretic mobility shift assay, with specific antibodies, showed that DB1 constitutively binds to this region whereas EGR1 binds in a T-cell activation-dependent manner. Overexpression of DB1 in Jurkat cells had no detectable effect on the transcription activity of the IL-3 promoter, in a transient-transfection assay. EGR1 and EGR2 increased IL-3 promoter activity when the transfected cells were stimulated with phorbol-12-myristate-13-acetate and A23187. When DB1 was cotransfected with a Tax expression vector, transcription activity of the IL-3 promoter induced by Tax was significantly increased, while EGR1 and EGR2 were without effect. These results suggest that EGR1 has a role in inducible transcription of the IL-3 gene, while DB1 sustains basal transcriptional activity and also cooperates with Tax to activate the IL-3 promoter.

Amino Acid Sequence↗

PubMed1994

Protective role of NO in hepatic microcirculatory dysfunction during endotoxemia.

Nitric oxide (NO) has been reported to have a protective function in attenuating hepatic injury during endotoxemia or sepsis. As a result, the role of NO in attenuating the hepatic microcirculatory alterations associated with endotoxemia was investigated in mice by in vivo microscopy. The livers were examined 2 h after intravenous injection of Escherichia coli 0111:B4 lipopolysaccharide (LPS) alone or in combination with inhibitors of the synthesis of NO, NG-nitro-L-arginine methyl ester or NG-monomethyl-L-arginine. In the animals treated with the combination of NO synthase inhibitors and LPS, leukocyte adherence was increased threefold above that in animals treated with LPS alone. This was accompanied by a 33% reduction in sinusoidal blood flow. Simultaneous administration of L-arginine, but not D-arginine, eliminated these microcirculatory disturbances. The results demonstrate that inhibition of LPS-stimulated NO production results in an early hepatic microvascular inflammatory response to a dose of endotoxin which by itself is scarcely inflammatory. This suggests that NO plays a significant role in stabilizing the hepatic microcirculation during endotoxemia, thereby helping to protect the liver from ischemia and leukocyte-induced oxidative injury.

Amino Acid Oxidoreductases↗

PubMed1993

cAMP activates the IL-5 promoter synergistically with phorbol ester through the signaling pathway involving protein kinase A in mouse thymoma line EL-4.

Expression of the IL-5 gene in T cells is induced in response to Ag stimulation; however, functional analysis of the IL-5 gene has been limited by lack of an appropriate transfection assay to facilitate measurement of the IL-5 promoter activity in response to T cell activation signals. Here, we describe a transient transfection system with which the IL-5 promoter activity can be assayed quantitatively. Using mouse thymoma line EL-4 cells, which produce several lymphokines including IL-2, IL-3, IL-4, IL-10, and GM-CSF in response to PMA, the effect of cAMP on IL-5 production was examined. These cells produce a low level of IL-5 when stimulated with PMA alone; however, N6, O2-dibutyryl cAMP (Bt2cAMP), in combination with PMA, augmented by more than tenfold the IL-5 production at the mRNA and the protein levels. Likewise, a transient transfection assay revealed that Bt2cAMP activated the IL-5 promoter more than tenfold, in a PMA-dependent manner, thereby indicating that two signals, PMA and cAMP, are required for optimal activation of the IL-5 promoter. Activation of the IL-5 promoter in response to Bt2cAMP and PMA depends on the region spanning from nucleotide position -1,200 to +33 relative to the transcription initiation site. Action of cAMP on the IL-5 promoter is mimicked by cotransfection of the expression plasmid containing cDNA encoding the catalytic subunit of protein kinase A, hence, cAMP probably exerts its action through the signaling pathway that involves protein kinase A. In contrast, Bt2cAMP almost completely inhibited the PMA-dependent activation of the endogenous IL-2 gene as well as the transfected IL-2 promoter. These results indicate that the IL-5 gene in EL-4 cells is positively regulated by cAMP in a manner opposite that for the IL-2 gene.

Animals↗

PubMed1993

Involvement of p53 gene mutations in human endometrial carcinomas.

Mutations in the p53 gene are associated with a wide variety of human malignancies. Point mutation in one allele and loss of the remaining one generally lead to inactivation of p53 protein. A high frequency of allelic losses corresponding to the 17p13.3 region that contained the p53 gene sequence was also noted in human endometrial carcinoma. Thus, in order to confirm involvement of the p53 gene in endometrial carcinogenesis, we searched for nucleotide sequence change in this gene in 42 endometrial carcinomas that had been subjected to previous LOH analyses. Using the polymerase-chain-reaction-single-strand conformation polymorphism (PCR-SSCP) method, we detected p53 gene mutations in 4 specimens. Two adenocarcinomas with allelic loss on 17p contained a mutant p53 gene in the allele that was retained. One specimen with a p53 gene mutation contained a 17q deletion but was uninformative for LOH on 17p. p53 gene mutation was also noted in the remaining stage-I carcinoma, though the 17p deletion was not detected in the previous LOH examination. However, 5 specimens with the LOH on 17p retained the wild-type p53 gene. In the remaining 33 specimens, both alleles of p53 gene seemed to be normal. The mutations observed in 2 specimens (cases 10 and 24), involving C-to-T and T-to-G substitutions, were located in a highly conserved region. However, the mutations identified in the remaining 2 cases (29 and 35) were at regions positioned outside conserved stretches.

Adenocarcinoma↗

PubMed1993

Reconstitution of the functional granulocyte macrophage colony stimulating factor promoter: evidence for distinct activation mechanisms that mediate the response to phorbol ester/calcium and human T cell leukemia virus type I Tax signals.

Functional elements in the promoter region of the mouse granulocyte-macrophage colony stimulating factor (GM-CSF) gene were assessed by constructing chimeric promoters linked to the bacterial chloramphenicol acetyltransferase (CAT) gene and by employing a transient transfection assay of human T cell leukemia Jurkat cells. We previously reported that CLE2/GC-box (at positions -95 to -73, which is homologous to the NF-kappa B binding site) and CLE0 (at positions to -40) of the mouse GM-CSF promoter are essential for transcriptional activation in response to phorbol-12-myristate-13-acetate (PMA)/calcium ionophore (A23187). Here we show that CLE2/GC-box and the NF-kappa B binding motif are functionally interchangeable and that CLE2/GC-box and CLE0 as a unit activate the basic GM-CSF promoter in response to PMA/calcium signals. This unit is also capable of activating heterologous promoters in response to PMA/calcium signals. In addition, we show that Tax, the trans-activator encoded by human T cell leukemia virus type I (HTLV-I), activates the GM-CSF promoter via CLE2/GC-box without the involvement of CLE0. These results indicate that PMA/A23187-dependent and Tax-dependent activation of the GM-CSF gene proceeds through distinct mechanisms.

Base Sequence↗

PubMed1992

Molecular cloning of bovine actin-like protein, actin2.

Actins are major cytoskeletal components and highly conserved in evolution. In mammals, there are six actin isoforms, a pair of which shows at least 93% identity in the amino acid sequence. We have cloned cDNA for a bovine protein that is distantly related to members of the mammalian actin isotypes. The predicted amino acid sequence (418 residues long, calculated molecular mass 47369) shows that this protein, which we have named actin2, exhibits 36% identity to mammalian actins and 60% identity to the yeast actin-like protein, act2. We have concluded that actin2 defines a new class of mammalian actin-like proteins. It was also revealed that actin2 messenger RNA is expressed in a broad range of tissues.

Actins↗

PubMed1992

Chromosome alterations contribute to neoplastic progression of transformed rat embryonal fibroblasts.

Three types of transformants derived from rat embryonal fibroblasts (REFs) corresponding to the different progressional stages were obtained: TF1 (human papillomavirus type 16 E7 (HPV16 E7) transfection alone) and TF2 (E7 plus adenovirus type 12(Ad12) E1b were immortalized, TF3 (E7 plus adenovirus type 5 (Ad5) E1B) was anchorage-independent but not tumorigenic, and TF4 (E7 plus EJ-ras) was tumorigenic. Cytogenetic investigations revealed that the cells carrying specific chromosomal abnormalities expanded clonally in three of the five TF4 tumorigenic clones, in contrast to the TF1-TF3 non-tumorigenic clones, which showed a normal karyotype. By the inoculation of TF4 into syngeneic rats, 8 tumor-derived clones were obtained. Clonal expansion of cells carrying specific chromosome changes was also remarkable in these tumor-derived clones. However, the type of rearrangements and the chromosomes involved in the abnormalities were not identical. In addition, it was shown that chromosome constitutions of the parental TF4 transformants were apparently inconsistent with those of their tumor-derived clones. However, the clonal nature of abnormalities observed in the parental and the tumor-derived clones suggested that these genetic events of cellular genomes corresponded with and possibly contributed to the progression of malignant phenotypes of cells.

Adenoviridae↗