Publications by authors named "Keiko Ichihara-Tanaka"

The linker histone H1fx is the least characterized member of the H1 family. To investigate the developmental changes of H1fx, we performed an immunohistochemical analysis of its expression pattern from embryos to adult mice. We found that H1fx was highly expressed during gastrulation, and was positive in all embryonic germ layers between E8.

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Background: Midkine is a heparin-binding cytokine involved in cell survival and various inflammatory processes. Midkine accumulates in senile plaques of patients with Alzheimer's disease, while it counteracts the cytotoxic effects of amyloid β-peptide and inhibits its oligomerization. The present study was conducted to understand the role of midkine upon plaque formation of amyloid β-peptide.

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Background: Midkine is a heparin-binding cytokine and is involved in etiology of various diseases. Thus, midkine inhibitors are expected to be helpful in treatment of many diseases.

Methods: We developed a simple assay for midkine activity based on midkine-dependent migration of osteblastic cells.

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Purpose: Neuroblastoma (NBL) is a tumor from neural crest cells, and is the most frequent solid tumor in children. Midkine (MK) is a pleiotropin analogon, which is frequently expressed in neuronal and epithelial tumors and is a marker for a poor clinical outcome. The aims of this study were to assess MK expression in NBL and investigate the correlation with clinical outcome.

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Purpose: Midkine (MK), a heparin-binding growth factor, has an important role in cancer progression. The outcome of patients with gastrointestinal stromal tumors (GISTs) is correlated with tumor size and mitotic count. The aim of this study was to determine MK expression in GISTs.

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Midkine and pleiotrophin form a family of growth factors. Mice deficient in one of the genes show few abnormalities on reproduction and development. To understand their roles in these processes, we produced mice deficient in both genes; the double deficient mice were born in only one third the number expected by Mendelian segregation and 4 weeks after birth weighed about half as much as wild-type mice.

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Midkine is a heparin-binding growth factor that promotes cell attachment and process extension in undifferentiated bipolar CG-4 cells, an oligodendroglial precursor cell line. We found that CG-4 cells expressed a non-proteoglycan form of neuroglycan C, known as a part-time transmembrane proteoglycan. We demonstrated that neuroglycan C before or after chondroitinase ABC treatment bound to a midkine affinity column.

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N-Acetylglucosamine 6-O-sulfotransferases (GlcNAc6STs) catalyze the transfer of sulfate from 3'-phosphoadenosine 5'-phosphosulfate (PAPS) to the C-6 position of non-reducing N-acetylglucosamine. N-acetylglucosamine 6-O-sulfotransferase-1 (GlcNAc6ST-1) is the first cloned GlcNAc6ST and is involved in the synthesis of the L-selectin ligand. We noticed conserved C-terminal segments among GlcNAc6STs and produced mutant enzymes to reveal the functional significance.

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A novel 114-kDa zinc finger protein, ZEC, has been found by cDNA cloning and characterized. ZEC was strongly expressed in the testis, liver and kidney, and also in embryonic stem cells. Epitope-tagged experiments indicated nuclear localization of ZEC.

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We isolated a mouse cDNA encoding a protein that contains a BEACH domain, 5 WD40 repeats and a FYVE domain, which we designated as BWF1. The mRNA is approximately 10 kb in size and encodes a protein consisting of 3508 amino acids with a predicted molecular weight of 385 kDa. BWF1 has 45% homology with the Drosophila protein, blue cheese (BCHS).

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N-acetylglucosamine-6-O-sulfotransferase (GlcNAc6ST) catalyzes the transfer of sulfate from 3'-phosphoadenosine 5'-phosphosulfate to the C-6 position of non-reducing GlcNAc. Human GlcNAc6ST-1 was expressed as a fusion protein with protein A in an insect cell line (Tn 5 cells) using the baculovirus system. The recombinant enzyme was purified to homogeneity by IgG Sepharose column chromatography.

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Midkine (MK), a heparin-binding growth factor, binds strongly to oversulfated structures in chondroitin sulfates (CSs) and heparan sulfate. To elucidate the carbohydrate structure actually involved in the strong binding, dissected brains from 13-day mouse embryos were incubated with [14C]-glucosamine. The labeled glycosaminoglycans were fractionated by MK-agarose affinity chromatography to a weakly binding fraction, which was eluted by 0.

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Midkine (MK), a heparin-binding growth factor, suppresses apoptosis of embryonic neurons in culture, induced by serum deprivation. Receptor-type protein tyrosine phosphatase zeta (PTP zeta) is a chondroitin sulfate proteoglycan with a transmembrane domain and intracellular tyrosine phosphatase domains. The activity of MK was abolished by digestion with chondroitinase ABC, or addition of the antibody to PTP zeta, while digestion with heparitinase showed no significant effect.

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