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N Shirafuji

Publications and source records attributed to N Shirafuji.

29 records · Page 2Linked to original sources
PubMed1990

Granulocyte colony-stimulating factor stimulates human mature neutrophilic granulocytes to produce interferon-alpha.

Granulocyte colony-stimulating factor (G-CSF) is a glycoprotein hormone that specifically stimulates both production and functional activation of neutrophils, while interferon-alpha (IFN-alpha) is known to suppress myelopoiesis, including neutrophil production in vivo and in vitro. On a possibility that IFN-alpha may operate as one of the inhibitory feedback factors in neutropoiesis, we examined whether neutrophils produce IFN-alpha in response to G-CSF. Northern blot analysis showed that messenger RNA (mRNA) for human IFN-alpha 1 became detectable time-dependently in highly purified human neutrophils incubated with purified recombinant human G-CSF (rhG-CSF). But such transcription was not observed either in neutrophils incubated with other neutrophil activators, such as formyl-methionyl-leucyl-phenylalanine (fMLP) or lipopolysaccharides (LPS), or in blood mononuclear cells incubated with rhG-CSF. In addition, radioimmunoassay for human IFN-alpha showed that its levels in culture medium of the rhG-CSF-treated neutrophils rose markedly (up to approximately 100 IU/mL/1 x 10(7) cells) in a time-dependent way, compared with those of nonstimulated neutrophils. These findings suggest that the G-CSF/IFN-alpha system may participate in the feedback regulatory loop of neutropoiesis.

Blotting, Northern↗
PubMed1990

Expression of granulocyte and granulocyte-macrophage colony-stimulating factors by human non-hematopoietic tumor cells.

The expression of granulocyte colony-stimulating factor (G-CSF) mRNA was studied in human non-hematopoietic tumors, including 18 cases of lung cancers 10 cases of stomach cancers, three cases of glioblastomas, and one case each of breast phyllode sarcoma, thyroid cancer, and hepatocellular carcinoma. Northern blot analysis detected G-CSF mRNA in two of the lung cancer cases, in one of the glioblastoma cases, and in both the breast phyllode sarcoma and hepatocellular carcinoma cases. Since G-CSF receptors were not detected on the tumor cells by 125I-G-CSF binding assay, G-CSF autocrine loop are probably not involved in the growth of these G-CSF-producing tumors. Interestingly, granulocyte-macrophage colony-stimulating factor (GM-CSF) mRNA was concomitantly expressed in most of these G-CSF-producing tumors. No major gene deletions or rearrangements of G-CSF and GM-CSF genes were demonstrated by Southern blot analysis in the tumors expressing G-CSF and GM-CSF mRNAs except for one of the glioblastomas (G3) in which one chromosome 17 allele was deleted. Although the mechanism of the concomitant expression of G-CSF and GM-CSF mRNA is unknown, relatively high frequency of this phenomenon suggests the presence of common transcriptional factors acting on regulatory regions of G-CSF and GM-CSF genomes.

Cell Line↗
PubMed1989

Human granulocyte colony-stimulating factor specifically binds to murine myeloblastic NFS-60 cells and activates their guanosine triphosphate binding proteins/adenylate cyclase system.

The specific binding of human granulocyte colony-stimulating factor (G-CSF) to its receptors on NFS-60 cells acts as a primer for cellular proliferation. There are approximately 400 binding sites per cell, with a binding constant of about 100 pmol/L. Before the proliferative response, the affinity constant of the membrane particulate fraction to 35S-labeled guanosine triphosphate-gamma-S (35S-GTP gamma S) and the intracellular cyclic adenylate monophosphate (cAMP) level increased in the presence of G-CSF to about 2.5-fold and about fivefold higher, respectively, than the levels seen in the absence of G-CSF. The increases were time-dependent, with a peak occurring 15 minutes after the addition of G-CSF at 37 degrees C. These findings suggest that, following the binding of the G-CSF to its surface receptors, the activation of the guanosine triphosphate (GTP)-binding protein/adenylate cyclase system may be involved in the proliferation of immature myeloid cells.

Adenylyl Cyclases↗
PubMed1989

Treatment of pure red cell aplasia that is resistant to conventional immunosuppressive therapy with intermittent administration of methotrexate.

Two patients with pure red cell aplasia were treated with intermittent administration of methotrexate. One who was refractory to conventional immunosuppressive therapy showed a favorable response to methotrexate within 2 weeks of treatment and entered complete remission. The other also showed an increase in reticulocytes within 3 weeks of methotrexate treatment. Although continuous administration of methotrexate was abandoned in the second case because of its hepatotoxicity, our results suggest that methotrexate may be effective in patients with pure red cell aplasia refractory to conventional immunosuppressive therapy.

Drug Resistance↗
PubMed1989

Serum granulocyte colony-stimulating factor levels in healthy volunteers and patients with various disorders as estimated by enzyme immunoassay.

In order to better understand the patho-physiologic role of granulocyte colony-stimulating factor (G-CSF), we estimated its serum levels in healthy persons and patients with various disorders, using a newly developed enzyme immunoassay (Motojima et al). In 49 of 56 normal healthy persons (88%), the levels were beneath the sensitivity of the assay (less than 30 pg/mL), while in the remaining seven healthy persons, the levels ranged from 33 to 163 pg/mL. On the other hand, nine of 11 patients (82%) with idiopathic aplastic anemia (AA), one patient with Fanconi's anemia, six of 12 patients (50%) with myelodysplastic syndrome (MDS), five of 12 patients (42%) with acute leukemia without any blast cells in the blood (M4: one, M5: one, L1: one, and L2: two), six of 18 patients (33%) with chronic myeloid leukemia (CML), one of two patients with chronic lymphoid leukemia (CLL), two of four patients with lung cancer, one patient with cyclic neutropenia, two of seven patients with malignant lymphoma, and four patients with acute infection had G-CSF levels ranging from 46 pg/mL to greater than 2,000 pg/mL. Interestingly, a reverse correlation between blood neutrophil count and serum G-CSF level was clearly demonstrated for aplastic anemia (r = -.8169, P less than .01). Moreover, it was found that the G-CSF level rose during the neutropenic phase of cyclic neutropenia and after chemotherapy or bone marrow transplantation (BMT) in three patients with leukemia; also high G-CSF levels were positively correlated to blood neutrophil counts in some cases of infectious disorders and lung cancer. The cellular sources and the mechanisms for production and secretion of circulating G-CSF were not investigated in this study, but the data presented here strongly indicate that G-CSF plays an important role as a circulating neutrophilopoietin.

Acquired Immunodeficiency Syndrome↗
PubMed1989

A new bioassay for human granulocyte colony-stimulating factor (hG-CSF) using murine myeloblastic NFS-60 cells as targets and estimation of its levels in sera from normal healthy persons and patients with infectious and hematological disorders.

[3H]thymidine uptake by NFS-60 cells in microcultures was found to increase in a linear fashion with the increasing doses of purified recombinant human granulocyte colony-stimulating factor (rhG-CSF). Such increases were found neither with rhG-CSF samples pretreated with rabbit anti-rhG-CSF serum nor with other human colony-stimulating factors such as granulocyte-macrophage colony-stimulating factor (hGM-CSF) or macrophage colony-stimulating factor (hM-CSF). Based on these findings, sera from normal persons and patients with severe infections or various hematological disorders were tested after dialysis using this system in order to determine whether G-CSF levels in sera can be estimated or not. In ten normal persons, five patients with acute myelogenous leukemia (AML M1, M2, and M3), five with myelodysplastic syndrome, and four with chronic myelogenous leukemia, no increases in [3H]thymidine uptake were found within the dose range of 0.4 microliters to 50 microliters. In contrast, linear dose responses parallel to a G-CSF standard curve were observed in one patient with a severe bacterial infection, four with aplastic anemia, two with acute myelomonocytic leukemia (AMMoL) (M4), and two with idiopathic neutropenia tested. From the standard curve, the probable levels of G-CSF were calculated as follows: approximately 200 pg/ml with infection, 130-220 pg/ml with aplastic anemia, 150 and 200 pg/ml with AMMoL, and 1120 and 1200 pg/ml with idiopathic neutropenia. The activities of sera were reduced by the anti-rhG-CSF serum pretreatment in the same way as documented in the case of rhG-CSF. Furthermore, the level in a patient with a severe infection became undetectable soon after elimination of the infection and blood neutrophil counts had returned to normal. These findings indicate that the microbioassay system will be useful for measuring circulating G-CSF levels which would fluctuate in accord with requirements for stimulating neutrophil production or with abnormal production of hG-CSF.

Adult↗
PubMed1988

Production of granulocyte colony-stimulating factor by acute myelomonocytic leukemia cells.

Two patients with acute myelomonocytic leukemia (AMMoL) were tested to determine whether or not their cells produced granulocyte colony-stimulating factor (G-CSF). Using the NFS-60 bioassay method, relatively high levels of G-CSF were demonstrated in the serum pre-treated with acid-dialysis and in the media conditioned by leukemia cells. Northern blot analysis for G-CSF using cDNA as a probe revealed that G-CSF production was increased at the mRNA level in the cells. No rearrangement at the DNA level, however, was observed by genomic Southern analysis. Our data indicate that the leukemic cells in AMMoL probably have the capacity to synthesize and secrete G-CSF.

Aged↗
PubMed1988

Phase I clinical study for recombinant human granulocyte colony-stimulating factor.

The pharmacokinetics, the safety and the efficacy of purified recombinant human granulocyte colony-stimulating factor (rh G-CSF) expressed in Chinese hamster ovary (CHO) cells were studied in normal healthy adults. Following the single subcutaneous dose, G-CSF levels in sera elevated in a dose-dependent way, with C-max of approximately 140 pg per ml, T-max of 4 hours and T-half of 5 hours at a dose of 10 micrograms per ml. In accord with the elevation, blood neutrophil counts rose promptly and transiently without any changes in the other blood cell counts. Degree and duration of the neutrophilia were apparently proportional to the rh G-CSF dose and, in turn, the G-CSF levels in sera. Single daily injections of rh G-CSF at a dose of 10 micrograms per body per day for 7 consecutive days did not bring on any accumulation of rh G-CSF in sera, and repeatedly induced neutrophilias following every injection. During the course of the injections, the chemiluminescence generating ability of blood neutrophils also rose. Peak value of the transient neutrophilias and level of the abilities tended to go down after 3 or 4 consecutive injections, presumably due to the limited number of mature neutrophils which can be released from the bone marrow in response to rh G-CSF. However, it was found that the M/E ratio becomes higher after the repeated dosing with an increased proportion of myeloid immature cells as well as increase in the levels of both erythroid and myeloid precursor cells in the bone marrow.(ABSTRACT TRUNCATED AT 250 WORDS)

Colony-Forming Units Assay↗
PubMed1987

Induction of neutrophilic granulocytosis in mice by administration of purified human native granulocyte colony-stimulating factor (G-CSF).

Mice were subcutaneously (sc) injected once a day for up to 15 days with a purified human native G-CSF sample at a dose of 2.5 micrograms/injection or with control samples with or without added endotoxin. In the G-CSF-treated mice, blood neutrophil counts began to rise as early as 2 hours after the first injection, reached a level 8 times above the preinjection level after 15 days of injections with marked elevation of all progenitor cell levels in spleen, and returned to normal within 48 hours after cessation of the injections. Such neutrophilia was observed even when endotoxin-resistant C3H/HeJ mice were used, but not in control mice. It is possible that repeated G-CSF injections after administration of cyclophosphamide (CY) in mice could accelerate recovery of granulopoiesis with a rather transient rise in blood neutrophil counts.

Animals↗