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H Takahira

Publications and source records attributed to H Takahira.

At least 19 recordsLinked to original sources
PubMed1997

Steel factor enhances integrin-mediated tyrosine phosphorylation of focal adhesion kinase (pp125FAK) and paxillin.

Integrin-mediated interaction of hematopoietic progenitor cells with bone marrow stromal extracellular matrix components is important in hematopoiesis. Focal adhesion kinase (pp125FAK) plays a central role in signal transduction through integrin receptors. We studied matrix-integrin interaction and subsequent signaling in human growth factor-dependent cell line, TF-1. Adherence of unstimulated TF-1 cells to fibronectin-coated wells was blocked by antiintegrin beta 1 and combination of anti-alpha 4 with anti-alpha 5 antibodies, indicating alpha 4 beta 1 and alpha 5 beta 1 integrin mediated adherence. Steel factor (SLF) increased TF-1 adhesion to fibronectin dose-dependently and 10(-7) mol/L wortmannin suppressed SLF-induced adhesion. Immunoprecipitation and immunoblotting with antiphosphotyrosine antibody showed that adherence of TF-1 cells to fibronectin without cytokine caused tyrosine phosphorylation of several proteins identified as pp125FAK and paxillin. SLF induced spreading of adherent TF-1 cells and enhanced tyrosine phosphorylation of pp125FAK and paxillin in a dose-dependent manner. Treatment with SLF without plating on fibronectin did not induce tyrosine phosphorylation of pp125FAK. Wortmannin, at 10(-7) mol/L, completely abolished SLF-induced enhancement of pp125FAK tyrosine phosphorylation, while c-kit autophosphorylation was not affected. This suggests that increase of pp125FAK tyrosine phosphorylation was mediated through a wortmannin sensitive pathway, rather than by direct action on c-kit tyrosine kinase. Treatment of adherent TF-1 cells with RGDS peptide plus anti-alpha 4 antibody also inhibited SLF-induced enhancement of pp125FAK tyrosine phosphorylation without detachment of TF-1 cells. These data suggest that SLF enhances integrin-fibronectin-dependent tyrosine phosphorylation of pp125FAK through activation of integrin ("inside-out" signaling) and following integrin occupancy. This establishes a novel linkage between c-kit/SLF pathway and integrin fibronectin signaling.

Cell Adhesion Molecules↗
PubMed1997

Immunoglobulin class switch from IgA1 to IgG2 and simultaneous association with Bence Jones proteinuria in the escape phase in a myeloma patient treated with interferon alpha.

Immunoglobulin (Ig) class switch from alpha1 to gamma2 associated with kappa-type Bence Jones proteinuria was evident in the escape phase of an IgA1 myeloma patient treated with interferon alpha (IFN alpha). The additional M-protein, IgG2-kappa, level rapidly increased and was associated with Bence Jones proteinuria, whereas monoclonal IgA1-kappa progressively declined. The N-terminal 21 amino acid sequences of the kappa-chains of monoclonal IgA1, IgG2 and the Bence Jones protein were the same. The N-terminal 15 amino acid sequence of the gamma2-chain was identical to that of the alpha1-chain. Based on these findings, the IgA1 myeloma cells underwent a class switch in CH gene expression from alpha1 to gamma2 with cell differentiation in vivo. The mechanism of the Ig class switching is discussed from three points of view: (1) Increase in immature and plasmablastic myeloma cells in the escape phase is susceptible to Ig class switching by the T-cell-derived cytokines. (2) We presumed that administered IFN alpha increased the amounts of secreted IFN gamma from the Th1 cells. (3) Due to a large quantity of IFN gamma, an inducer of Cgamma2 germline transcript, Ig class switching occurred stepwise from the alpha1 constant region gene to the next 3'CH gamma2 gene.

Aged↗
PubMed1997

Retroviral mediated gene transfer of Flt3 ligand enhances proliferation and MAP kinase activity of AML5 cells.

Flt3/flk-2 ligand (Flt3-L) co-stimulates and synergizes with cytokines such as granulocyte-macrophage colony stimulating factor, granulocyte colony stimulating factor (G-CSF), interleukin-3 (IL-3), and erythropoietin in the proliferation of bone marrow and cord blood hematopoietic stem and progenitor cells. To study the biological effects of Flt3-L on the Flt3-L responsive AML5 cell line, the retroviral vector L(Flt3-L)SN was constructed based on the vector LXSN, but containing the human Flt3-L cDNA transcriptionally regulated by the Mo-MLV LTR. High-titer amphotropic producer cells that generated 10(6) cfu/mL after shuttle packaging through ecotropic packaging cells were isolated. AML5 cells were cultured overnight with L(Flt3-L)SN retroviral supernatant, 8 micrograms/mL polybrene, and 100 U/mL G-CSF, and expanded 1 week in medium with G-CSF. Transduced cells were selected in medium containing 0.4 mg/mL G418 and then in medium with 1.0 mg/mL G418. Retroviral mediated gene transfer in G418-resistant cells was confirmed after amplification by PCR of neo-specific sequences in genomic DNA. Northern blot analysis demonstrated L(Flt3-L)SN mRNA expression. Soluble Flt3-L was undetectable (< 100 pg/mL) by ELISA assay of conditioned medium from transduced cells, but Flt3-L was detected on the surface of AML5 cells by FACS analysis. Cells were plated in colony assay with and without 100 ng/mL Flt3-L, 100 U/mL G-CSF, and the combination. Gene transfer or growth factor treatment increased somewhat the clonogenicity of the nontransduced AML5 cells. More strikingly, L(Flt3-L)SN and each growth factor combination greatly increased the size of the resultant colonies such that the size of colonies from AML5/Flt3-L cells without added growth factor approximated that of the AML5 cells stimulated by exogenous soluble Flt3-L. Moreover, MAP kinase activity in L(Flt3-L)SN-transduced cells cultured without soluble Flt3-L was increased to the level induced in control cells by soluble Flt3-L. These results indicate that retroviral mediated gene transfer and autologous expression of the Flt3-L enhances growth and intracellular signaling of AML5 cells, information that should be of value for studying the effects of Flt3-L on immature subsets of primary hematopoietic stem and progenitor cells.

Calcium-Calmodulin-Dependent Protein Kinases↗
PubMed1997

Cross-linking of integrins induces tyrosine phosphorylation of the proto-oncogene product Vav and the protein tyrosine kinase Syk in human factor-dependent myeloid cells.

Attachment to extracellular matrix is important in the regulation of proliferation and differentiation of hematopoietic stem and progenitor cells. Post-ligand occupancy events of integrin receptors in myeloid cells are largely unknown. We examined early signaling events after stimulation of integrin receptors (outside-in signal) using a cross-linking system in a growth factor-dependent myeloid cell line, M07e, alpha 4, alpha 5, and beta 1 integrin cross-linking induced a similar pattern of transient tyrosine phosphorylation of cellular proteins. The approximate molecular weights of these phosphoproteins were M(r) 150,000, M(r) 120,000-125,000, M(r) 95,000, M(r) 70,000, M(r) 60,000, and M(r) 40,000-50,000. Vav, Syk, and Erk2 were identified as some of the tyrosine-phosphorylated proteins, and their weights were M(r) 95,000, M(r) 70,000, and M(r) 40,000-50,000, respectively. Erk2 and Vav were also tyrosine-phosphorylated by stimulation with Steel factor (SLF) and granulocyte macrophage colony-stimulating factor, whereas tyrosine phosphorylation of Syk was not induced by stimulation with these cytokines. The degree of tyrosine phosphorylation of Vav through integrin engagement was almost equal to that by SLF stimulation, whereas that of Erk2 was much weaker than with SLF stimulation. Upon integrin engagement, antibodies raised against Syk coprecipitated several tyrosine-phosphorylated proteins. In vitro binding assays demonstrated that, among these Syk-associated proteins, pp40, which differed from Erks, Crk, and Crkl, binds Syk through SH2 domains of Syk and is a prominent tyrosine-phosphorylated protein in integrin cross-linked cells. These results suggest that tyrosine phosphorylation of Vav and Erk2 in myeloid cells might be regulated by both integrins and cytokines in the bone marrow microenvironment, whereas Syk might be involved in a distinct pathway from the shared between integrins and cytokines in myeloid cells.

Blotting, Western↗
PubMed1996

Steel factor induces serine phosphorylation of Stat3 in human growth factor-dependent myeloid cell lines.

Steel factor (SLF) acts synergistically with various hematopoietic growth factors that use the Jak-Stat pathways in vivo and in vitro, although the contribution by SLF to this pathway is unknown. We show here that SLF induces time- and dose-dependent phosphorylation of Stat3 in the human growth factor-dependent cell lines MO7e and TF-1. This phosphorylation occurs exclusively on serine residues. Simultaneous stimulation with SLF plus other cytokines that induce tyrosine phosphorylation of Stat3, such as interleukin-9 (IL-9) in MO7e cells or IL-6 in TF-1 cells, resulted in tyrosine phosphorylation and enhanced serine phosphorylation of Stat3. Serine phosphorylation alone did not promote nuclear translocation or DNA binding activity to the sis-inducible element of Stat3. However, costimulation with SLF plus IL-9 in MO7e cells resulted in the nuclear translocation of serine-hyperphosphorylated Stat3. Serine phosphorylation of Stat3 was also observed by the stimulation of cells with granulocyte-macrophage colony-stimulating factor and IL-3, which do not induce tyrosine phosphorylation of Stat3. These results suggest that SLF might modulate the Jak-Stat3 pathway by serine phosphorylation and that the Jak-Stat pathway may be differentially regulated by the combinational stimulation of two or more cytokines.

Base Sequence↗
PubMed1996

Flt3 ligand prolongs survival of CD34++ + human umbilical cord blood myeloid progenitors in serum-depleted culture medium.

Flt3 Ligand (L), a newly identified stimulating/co-stimulating cytokine for hematopoietic stem and progenitor cells, was assessed for its capacity, in comparison to that of steel factor, to prolong the survival in culture of hematopoietic stem and progenitor cells from CD34++ + human cord blood. The addition of Flt3-L to serum-depleted cultures significantly prolonged the survival of high-proliferative-potential colony-forming cells (HPP-CFC) as well as that of multipotential (CFU-GEMM) and granulocyte-macrophage (CFU-GM) progenitor cells. The concentrations of Flt3-L necessary for these effects were similar to those of SLF, and low concentrations of Flt3-L and SLF which were inactive when used alone were active in these effects when used together. These results may be of practical value for short-term storage, treatment and/or transport of purified populations of cord blood stem and progenitor cells.

Antigens, CD34↗
PubMed1996

AILD-like dysplasia transformed in AILD-type T cell lymphoma in an HTLV-1 carrier: usefulness of interferon-alpha.

A 61-year-old Japanese woman who was an HTLV-1 carrier had angioimmunoblastic lymphadenopathy with dysproteinemia (AILD)-like dysplasia that transformed into AILD-type lymphoma after 3 years. Complete remission was achieved with interferon-alpha (IFN-alpha) treatment following a previous combination of anticancer drugs. IFN-alpha was also effective for maintenance therapy after this complete, albeit transient, remission. From clinical and pathological studies on AILD patients, it appears that AILD may in some cases be the consequence of an immune dysfunction caused by HTLV-1 infection and that AILD-type lymphoma is a malignant disorder of peripheral T cell clones different from those T cells incorporating the HTLV-1 virus.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1996

Acute leukemias expressing p210-and p 190-type bcr/abl mRNAs: report of two cases and review of the literature.

We report two patients with acute leukemias who expressed two types of bcr/abl mRNA. The first case was an 8-year-old boy with acute mixed leukemia in whom the Ph1 chromosome and p210/p190 types of bcr/abl mRNAs were detected at diagnosis. The second case was a 39-year-old male with acute nonlymphocytic leukemia transformed from myelodysplastic syndrome (refractory anemia with excess of blasts). In the latter case, the p210-type mRNA appeared after leukemic transformation, and the p190-type transcript was detected only during the late stage when the Ph1 chromosome was first observed. The leukemias in these two patients were aggressive in their clinical courses. We conclude that the dual expression of p210 and p190 types of bcr/abl is a factor indicating a poor prognosis, and that, in some patients, p190-type bcr/abl may contribute to disease progression.

Acute Disease↗
PubMed1996

Flt3-ligand production by human bone marrow stromal cells.

Bone marrow stromal cells are important sources of cytokines and growth factors which participate in regulation of proliferation and differentiation of hematopoietic stem and progenitor cells. Recently flt3/flk-2-ligand (flt3-L), a new growth factor which uses a membrane tyrosine kinase receptor, was cloned. It is expressed in transmembrane and soluble forms and stimulates/co-stimulates proliferation and colony formation of hematopoietic stem/progenitor cells. It has not been reported whether flt3-L is produced by cells of the hematopoietic bone marrow microenvironment. We demonstrate the expression of flt3-L in bone marrow fibroblasts (BMF) and in stromal cells of adherent layers of long-term bone marrow cultures by RT-PCR, Northern blot, immunocytochemistry and FACS analysis. The latter two methods localized flt3-L intracellularly and on cell membranes. Treatment with interleukin-1 alpha increased the expression of flt3-L in BMF. This demonstrates production and modulation of flt3-L in stromal cells of human bone marrow.

Base Sequence↗
PubMed1995

A novel mutation causing an aberrant splicing in the protein 4.2 gene associated with hereditary spherocytosis (protein 4.2Notame).

We investigated a Japanese patient with protein 4.2 deficiency. SDS-PAGE showed a complete deficiency of protein 4.2, while Western blot analysis revealed a marked decrease in the amount of protein 4.2, and the existence of a doublet of 74 and 72 kDa bands. Direct sequencing and dot-blot hybridization with allele-specific oligonucleotide probes indicated that the proband was compound heterozygous for a missense mutation in codon 142 with Ala-->Thr (GCT-->ACT) and a single nucleotide substitution (G-->A) of the first base of intron 6 (G-->A) of the protein 4.2 gene. The former is the commonest mutation observed in cases of protein 4.2 deficiency, whereas the latter is a novel mutation, located within the consensus sequence of the 5' splicing site (AGGU) (Protein 4.2Notame). RT-PCR analysis using total RNA isolated from reticulocytes of the proband revealed that the intron 6 donor site mutation causes an abnormal splicing; exon 6 is spliced out with intron 6. The abnormal mRNA has a premature termination codon, as the result of a frameshift, and this instability may lead to degradation. Thus, there is a close relation between this mutation and the molecular pathogenesis of protein 4.2 deficiency.

Base Sequence↗
PubMed1994

[Bone marrow transplantation for a patient with ALL from her 75-year-old mother using cryopreserved bone marrow cells].

We report a 42-year-old woman with acute lymphoblastic leukemia who received allogeneic bone marrow transplantation (BMT) in the first remission from her 75-year-old, HLA-identical, MLC-non-reactive mother. Considering the difficulty to obtain a sufficient number of bone marrow cells from such an old donor, we harvested the cells (2.31 x 10(8)/kg) on day -37 and cryopreserved them until use. BMT was performed on June 3rd, 1993 after conditioning regimen with total body irradiation, high-dose AraC and cyclophosphamide. Graft-versus-host disease (GVHD) prophylaxisis was attempted by cyclosporin A and short-term methtrexate. Her hematopoietic recovery was favorable with no signs and symptoms of GVHD as far as day 218.

Adult↗
PubMed1994

Establishment of a human myeloma cell line with growth-promoting activity for bone marrow-derived fibroblastoid colony-forming cells.

A human myeloma cell line, PCM6, was newly established from peripheral blood of a patient with advanced IgG myeloma by addition of recombinant interleukin-6 (IL-6) in culture. PCM6 cells had a morphology typical of mature plasma cells. Cytogenetic and surface marker studies confirmed that PCM6 cells were identical to fresh myeloma cells. Coculture of PCM6 cells with normal bone marrow mononuclear cells resulted in increased colony size of bone marrow-derived fibroblastoid colony-forming cells (CFU-F). Conditioned medium of PCM6 (PCM6-CM) cells increased the CFU-F colony size in a dose-dependent manner. The activity was labile to trypsin treatment but was heat stable (60 degrees C, 30 minutes). Molecular weight of the activity was approximately 165 kd by Sephacryl S-300 gel filtration. Platelet-derived growth factor (PDGF), epidermal growth factor (EGF), transforming growth factor-beta (TGF-beta), and IL-1 beta were not detectable in the conditioned medium. These findings suggest that in some myeloma cases, bone marrow stroma may be affected by CFU-F growth-promoting activity.

Antigens, Surface↗
PubMed1993

Parvovirus B19-associated haemophagocytosis in Evans syndrome: aplastic crisis accompanied by severe thrombocytopenia.

A 36-year-old man who had been treated for Evans syndrome (ES) developed an aplastic crisis caused by acute human parvovirus B19 (HPV) infection. Profound thrombocytopenia (8.0 x 10(9)/l) followed with a sudden increase in platelet-associated IgG (PAIgG) (1376.9 ng/10(7) plts). Bone marrow examination revealed a considerable number of haemophagocytic histiocytes without any disturbance of megakaryopoiesis. To our knowledge this is the first case of aplastic crisis with virus-associated haemophagocytosis in a patient with ES, which provides an interesting insight into the mechanisms for thrombocytopenia in HPV infection.

Adult↗
PubMed1993

[A case of primary non-Hodgkin lymphoma of the adrenal gland presenting with Addison's disease].

A 69-year-old male was admitted to our hospital complaining of skin pigmentation. Masses in bilateral adrenal glands were noted on computed tomography. An exploratory laparotomy revealed malignant lymphoma confined to the bilateral adrenal glands. Histological diagnosis was diffuse mixed-cell type, B-cell lymphoma. Laboratory tests disclosed an elevated ACTH level and decreased urinary 17KS and 170HCS secretion. Based on hypofunction of adrenal glands and skin pigmentation, the patient was diagnosed as having Addison's disease. After complete remission with combination chemotherapy, adrenal function recovered normal and pigmentation disappeared, Addison's disease is an extremely rare complication of primary malignant lymphoma of the adrenal gland.

Addison Disease↗
PubMed1992

Analysis of clonality at the level of progenitors in chronic myelogenous leukaemia using the polymerase chain reaction.

The Philadelphia (Ph1) chromosome is a specific structural abnormality in which the abl oncogene is activated due to the formation of the novel chimeric gene, bcr/abl. To investigate the clinicopathological role of bcr/abl in Ph1-positive chronic myelogenous leukaemia (CML), we studied the clonal origin of haematopoietic progenitors by detecting bcr/abl mRNA in a single haematopoietic colony using the polymerase chain reaction (PCR). Nine patients with CML were examined. In 5 chronic phase patients, all granulocyte/macrophage (CFU-GM) and erythroid (BFU-E) progenitor-derived colonies were positive for bcr/abl mRNA. Colonies in which the transcripts were not detectable were observed in 4 patients. These 4 patients included one patient with a normal karyotype and without splenomegaly, a patient with cyclic oscillation of her white blood cell level, a patient treated with busulfan and interferon-alpha (INF-alpha), and a patient relapsing after allogenic bone marrow transplantation (BMT). Our observations indicate that detection of Ph1-positive clones by PCR may be used to evaluate clinical stages and the effects of treatment in CML.

Adolescent↗
PubMed1992

In vivo recording of electrical activity of canine tracheal smooth muscle.

Electrical activity of the tracheal smooth muscle was studied using extracellular bipolar electrodes in 37 decerebrate, paralyzed, and mechanically ventilated dogs. A spontaneous oscillatory potential that consisted of a slow sinusoidal wave of 0.57 +/- 0.13 (SD) Hz mean frequency but lacked a fast spike component was recorded from 15 dogs. Lung collapse accomplished by bilateral pneumothoraxes evoked or augmented the slow potentials that were associated with an increase in tracheal muscle contraction in 26 dogs. This suggests that the inputs from the airway mechanoreceptors reflexly activate the tracheal smooth muscle cells. Bilateral vagal transection abolished both the spontaneous and the reflexly evoked slow waves and provided relaxation of the tracheal smooth muscle. Electrical stimulation of the distal nerve with a train pulse (0.5 ms, 1-30 Hz) evoked slow-wave oscillatory potentials accompanied by a contraction of the tracheal smooth muscle in all the experimental animals. Our observations in this in vivo study confirm that the electrical activity of tracheal smooth muscle consists of slow oscillatory potentials and that tracheal contraction is at least partly coupled to the slow-wave activity of the smooth muscle.

Action Potentials↗
PubMed1992

[Effects of tiropramide on the activity of lower urinary tract in dogs and its interpretation].

The rhythmic contractions of urinary bladder under constant volume condition were evoked in decerebrate and de-anesthetized dogs, while various myogenic and nerve-mediated electrical and mechanical activities of smooth muscles were recorded from in vivo pelvic viscera. The vesical rhythmic contractions were transiently and partially blocked by intravenous application of tiropromide. This 'partial' block showed a good contrast to the 'complete' block of identical contractions, which was observed after application of oxybutynin, known as a potent anti-muscarinic drug. The bladder voiding cycles were observed in other decerebrate dogs, while the warmed Ringer solution was infused at a steady rate into the dome of the bladder until principal voiding contraction occurred in cystometric recordings. The initiation of voiding contraction was markedly delayed after intravenous injection of tiropramide. The delay of principal contraction was found to be due to successive appearance of falling waves in cystometric recordings. As a evident contrast, terodiline caused a significant reduction of voiding contraction height and shortening of clonic discharge phase of external urethral sphincters during voiding cycle. It is concluded that tiropramide does not reveal anti-muscarinic action which oxybutynin or terodiline does really show, instead tiropramide acts principally on bladder detrusor itself, especially on its relaxation phase of premature contraction to be prolonged. The evidences were also presented for electrophysiological identification of bladder detrusor and urethral smooth muscle.

Action Potentials↗