Publications by authors named "Tohru Marunouchi"

Background: Three members of the Myt/NZF family of transcription factors are involved in many processes of vertebrate development. Several studies have reported that Myt1/NZF-2 has a regulatory function in the development of cultured oligodendrocyte progenitors or in neuronal differentiation during Xenopus primary neurogenesis. However, little is known about the proper function of Myt/NZF family proteins during mammalian nervous system development.

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During mammalian central nervous system development, neural stem cells differentiate and then mature into various types of neurons. Myelin transcription factor (Myt)/neural zinc finger (NZF) family proteins were first identified as myelin proteolipid protein promoter binding factors and were shown to be involved in oligodendrocyte development. In this study, we found that Myt/NZF family molecules were expressed during neuronal differentiation in vivo and in vitro.

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Using a newly established fixation method and immunohistochemical methods, we precisely described the regions of cells stained with various antibodies relating to cell proliferation; this method enabled us to make cellular-level diagrams of the epithelium in which the position of every lens epithelial cell (LEC) was determined in reference to the cell located at the top of the bow area. The proliferating activity of LECs of 4-week-old (4W) mice was examined either by labeling with 5-bromodeoxyuridine (BrdU) in vivo or by measuring the amount of mRNA prepared from LECs, which had been separated into the posterior part, containing the germinative zone, and the anterior part and then cultured. The epithelial region stained with antibody for proliferating cell nuclear antigen (PCNA) and cyclin D1 remained relatively constant during the study period, although the positive region was reduced a little from embryonic day 18 (E18) to 12W.

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Background: Embryonic stem (ES) cells, bone marrow, adipose tissue or other genetically modified stem cells are being widely used in basic research in the field of regenerative medicine. However, there is no specific surface antigen that can be used as a marker of multipotent stem cells.

Objective: We tried to isolate and collect putative multipotent stem cells from mouse subcutaneous adipose tissue using the p75 neurotrophin receptor (p75NTR) as a marker.

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Notch family molecules are transmembrane receptors that play various roles in contact-dependent cell-cell interactions in a wide range of organs. In the brain, Notch2, but not the other members of Notch, is expressed in the choroid plexus at an exceptionally high level. We immunohistochemically examined the cellular and subcellular localization of Notch2 protein in the choroid plexus using confocal and electron microscopy.

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In the mammalian testis, spermatogenesis is initiated from a subset of stem cells belonging to undifferentiated type A spermatogonia. In spite of the biologic significance of undifferentiated type A spermatogonia, little is known about their behavior and properties because of a lack of specific cell surface markers. Here we show that CDH1 (previously known as E-cadherin) is expressed specifically in undifferentiated type A spermatogonia in the mouse testis.

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Renal enlargement in polycystic kidney disease (PKD) is caused by the proliferation of mural epithelial cells and transepithelial fluid secretion into the cavities of innumerable cysts. Arginine vasopressin (AVP) stimulates the proliferation of human PKD cells in vitro via cAMP-dependent activation of the B-Raf/MEK (MAPK/ERK kinase/extracellular signal-regulated kinase (ERK) pathway. ERK activity is elevated in cells that line the cysts in animals with PKD, and AVP receptor antagonists reduce ERK activity and halt disease progression.

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Chondroitin sulfate is a long sulfated polysaccharide with enormous structural heterogeneity that binds with various proteins, such as growth factors, in a structure-dependent manner. In this study, we analyzed the expression of chondroitin sulfate in the postnatally developing cerebellar cortex by using three monoclonal antibodies against chondroitin sulfate, MO-225, 2H6, and CS-56, which recognize different structural domains in this polysaccharide. During the first postnatal week, the patterns of immunohistochemical staining made by these antibodies were quite similar, and the molecular layer, the granule cell layer, and Bergmann glial fibers in the external granular layer were densely stained.

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The characteristic folial pattern of the mouse cerebellum is formed during postnatal development. We observed this process in C57BL/6J (B6) mice in detail, and found an abnormal folial pattern in a specific region (lobules VIII and IX of the vermis) in a substantial number of B6 mice. The frequency of this abnormality increased during postnatal development and reached 55% in the adult.

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Androgens have been implicated in mediating disease escalation in autosomal dominant polycystic kidney disease (ADPKD). Dihydrotestosterone (DHT), an agonist, and flutamide (FLT), an antagonist, were administered to Han:SPRD rats with ADPKD, and the role of androgen receptor (AR) abundance and activation on the enlargement and function of cystic kidneys was evaluated. Renal AR abundance determined by immunoblots in 8- to 10-wk-old Cy/+ male rats was naturally increased four-fold above that of littermate +/+ controls.

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The total transforming growth factor (TGF) beta(2) concentration in the anterior chamber aqueous humor of 96 cataract patients with ages ranging from 17 to 88 years was measured using ELISA to investigate the changes that occur with age, difference of axial length, difference of localization of opacification of the cataractous lens and complications with other eye diseases. It was found that the total TGF-beta(2) concentration (1) decreases with age, (2) shows slight changes with axial length, (3) has slight changes with difference of localization of opacification, (4) is significantly high in patients with concurrent open-angle glaucoma (p < 0.05), (5) is high in patients with complicating diabetes who have undergone panretinal photocoagulation for diabetic retinopathy (p < 0.

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Although mRNAs of Notch receptors and their ligands are known to be expressed in the postnatally developing rodent cerebellum, their protein localization has been poorly investigated. In the present study, we immunohistochemically examined localization of Notch receptors and their ligands during postnatal cerebellar development in rats. During the first two postnatal weeks, intense signals of Notch1-3 were localized in Bergmann fibers (radial fibers of Bergmann glia), as confirmed by double fluorescent immunohistochemistry.

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PTPzeta/RPTPbeta, a receptor-type protein tyrosine phosphatase synthesized as a chondroitin sulfate (CS) proteoglycan, uses a heparin-binding growth factor pleiotrophin (PTN) as a ligand, in which the CS portion plays an essential role in ligand binding. Using an organotypic slice culture system, we tested the hypothesis that PTN-PTPzeta signaling is involved in the morphogenesis of Purkinje cell dendrites. An aberrant morphology of Purkinje cell dendrites such as multiple and disoriented primary dendrites was induced in slice cultures by (1) addition of a polyclonal antibody against the extracellular domain of PTPzeta, (2) inhibition of protein tyrosine phosphatase activity, (3) enzymatic removal of the CS chains, (4) addition of exogenous CS chains, and (5) addition of exogenous PTN, all of which disturb PTN-PTPzeta signaling.

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Fas, Caspase 3 and single-stranded (ss) DNA are indicators of cell apoptosis. In the present study, Fas, Caspase 3 and ssDNA were found in the pyramidal opaque portions of anterior polar cataracts and the opaque portions of the anterior capsulotomy margin following intraocular lens (IOL) implantation. It is thus possible that apoptosis occurs in the lens epithelial cells in these regions, and this finding may be related to the fact that the pyramidal opaque portion of anterior polar cataracts and the opaque portions of the anterior capsulotomy margin following IOL implantation do not spread beyond a given range.

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The expression pattern of Notch family receptors during mouse spermatogenesis was examined by immunohistochemistry. The entire cytoplasm of spermatogonia, spermatocytes and spermatids showed staining with antibodies against extracellular domains of Notch1, 2 and 4. In contrast, the nuclei of spermatogonia showed staining with an antibody against the intracellular domain of Notch3, and the nuclei of spermatocytes and spermatids showed staining with antibodies against the intracellular domains of Notch1 and 4.

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NZF-2 (MyT1) is a member of C2HC-type zinc finger transcription factors. A novel form of mouse NZF-2 has been isolated. This novel form, NZF-2b, has an additional C2HC-type zinc finger motif.

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Notch proteins are transmembrane receptors involved in cell-fate determination throughout development. Targeted disruption of either the Notch1 or Notch2 gene in mice results in embryonic lethality around embryonic day (E) 10.5 with widespread cell death.

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