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T Suda

Publications and source records attributed to T Suda.

At least 451 records · Page 25Linked to original sources
PubMed1993

Human primitive hematopoietic progenitor cells are more enriched in KITlow cells than in KIThigh cells.

To clarify the phenotypes of various classes of human hematopoietic progenitor cells, we used a multicolor staining protocol in conjunction with CD34 and a newly developed mouse antihuman c-kit proto-oncogene product (KIT) monoclonal antibody (MoAb). We characterized three cell fractions in CD34+ cells that express KITlow and KIThigh cells in addition to KIT- cells. A clonogenic assay showed that most granulocyte-macrophage colony-forming cells (GM-CFC) were present in CD34+KIThigh populations, whereas erythroid burst-forming cells (BFU-E) were detected mainly in the CD34+KITlow population. CD34(+)-KIT- fraction contained a small number of BFU-E. Morphologic analysis showed that blast-like cells were more enriched in the CD34+KITlow fraction. KITlow cells contained CD34+CD38- cells that were considered to be very primitive progenitor cells, as determined by a replating assay. To clarify the biologic differences between both fractions, we examined the more primitive progenitor cell functions by assessing long-term culture-initiating cells (LTC-IC) on the stromal cells. At week 2, more CFC recovered from the culture in the fraction initiated with a CD34+KIThigh population. However, more LTC-IC were present during weeks 5 to 9 in the CD34+KITlow population. These results indicate that primitive progenitors are more enriched in the KITlow population and that the KIThigh population contains many GM-committed progenitor cells. We also showed that anti-KIT MoAb inhibited the ability of CD34+ cells to generate CFC on the stromal layer in the LTC system. This suppressive effect was more evident in the generation of BFU-E by CD34+KITlow cells. Moreover, we confirmed that CD34+KIThigh cells emerged from CD34+KITlow cells during coculture with allogeneic stromal cells or from liquid culture in the presence of stem cell factor (SCF), interleukin-6, and erythropoietin. These results emphasize the pivotal role of the KIT and SCF interaction in hematopoiesis and indicate that KITlow cells are more primitive than KIThigh cells.

Animals↗
PubMed1993

Saireito (a Chinese herbal drug)-stimulated secretion and synthesis of pituitary ACTH are mediated by hypothalamic corticotropin-releasing factor.

Administration of Saireito, a Saiko agent (a Chinese herbal drug), via a stomach cannula stimulates ACTH release and proopiomelanocortin, the precursor for ACTH, gene expression in the rat anterior pituitary. To study whether Saireito-stimulated secretion and synthesis of ACTH are mediated by hypothalamic corticotropin-releasing factor (CRF), we examined the effect of passive immunization of endogenous CRF by i.v. administration of CRF antiserum on Saireito-increased plasma ACTH levels and proopiomelanocortin gene expression in the rat anterior pituitary, under pentobarbital anesthesia. CRF antiserum inhibited Saireito-induced plasma ACTH levels and proopiomelanocortin mRNA levels in the anterior pituitary. This result indicates that Saireito stimulates CRF neurons to increase CRF release, which stimulates secretion and synthesis of ACTH.

Adrenocorticotropic Hormone↗
PubMed1993

Molecular cloning and characterization of mouse TIE and TEK receptor tyrosine kinase genes and their expression in hematopoietic stem cells.

To identify receptor tyrosine kinases (RTKs) critical to early hematopoiesis, we performed polymerase chain reaction-based cloning from yolk sac and highly enriched bone marrow hematopoietic stem cells (HSCs). Characterization of two novel genes of their full-length cDNA sequences revealed that they were mouse homologues of the endothelial cell RTK genes, TIE and TEK. They shared a unique structural property of coexistent immunoglobulin-like domain, epidermal growth factor-like repeats, and fibronectin type III repeats in their extracellular domains. Both genes were expressed in a similar fashion in adult tissues and primitive hematopoietic cells, predominantly in the bone marrow HSCs.

Amino Acid Sequence↗
PubMed1993

Lethal effect of the anti-Fas antibody in mice.

During mammalian development, many cells are programmed to die most mediated by apoptosis. The Fas antigen coded by the structural gene for mouse lymphoproliferation mutation (lpr), is a cell surface protein belonging to the tumour necrosis factor/nerve growth factor receptor family, and mediates apoptosis. The Fas antigen messenger RNA is expressed in the thymus, liver, heart, lung and ovary. We prepared a monoclonal antibody against mouse Fas antigen, which immunoprecipitated the antigen (M(r) 45K) and had cytolytic activity against cell lines expressing mouse Fas antigen. We report here that staining of mouse thymocytes with the antibody indicated that thymocytes from the wild-type and lprcg mice expressed the Fas antigen, whereas little expression of the Fas antigen was found in lpr mice. Intraperitoneal administration of the anti-Fas antibody into mice rapidly killed the wild-type mice but neither lpr nor lprcg mice. Biochemical, histological and electron microscope analyses indicated severe damage of the liver by apoptosis. These findings suggest that the Fas antigen is important in programmed cell death in the liver, and may be involved in fulminant hepatitis in some cases.

Animals↗
PubMed1993

Highly enhanced fucosylation of alpha-fetoprotein in patients with germ cell tumor.

BACKGROUND: We have recently reported that simultaneous determination of the fucosylation and glucosaminylation of alpha-fetoprotein (AFP) was useful in the differential diagnosis of various liver diseases. Here, we measured these indices in germ cell tumor and compared them with those in various diseases to reveal the characteristic feature of the carbohydrate moiety of AFP in this tumor. METHODS: Fucosylation and glucosaminylation indices of AFP were determined for 743 serum samples from 10 patients with germ cell tumor, 437 with hepatocellular carcinoma (HCC), 241 with benign liver diseases (24 patients with acute viral hepatitis, 99 with chronic hepatitis, and 118 with hepatic cirrhosis), and 55 with carcinoma metastatic to the liver from digestive organs (41 from stomach, 10 from gallbladder, 2 from pancreas, and 2 from colon) by crossed immunoaffinoelectrophesis in the presence of concanavalin A and Lens culinaris agglutinin. RESULTS: The fucosylation index of AFP in germ cell tumors (99% +/- 2%, mean +/- SD) was higher than those in HCC (39% +/- 31%), carcinoma metastatic to the liver (76% +/- 27%), and benign liver diseases (4% +/- 7%); the differences were statistically significant (P < 0.001). The glucosaminylation index of AFP in germ cell tumor (45% +/- 20%) also was significantly higher than those in HCC (4% +/- 4%) and in benign liver diseases (1% +/- 4%) (P < 0.001). The difference in mean percentage of the glucosaminylation index, however, was not significant between germ cell tumors (45% +/- 20%) and carcinoma metastatic to the liver (39% +/- 23%). CONCLUSIONS: The current study indicates that the most characteristic feature of glycosylation of AFP in germ cell tumors is fucosylation rather than glucosaminylation.

Adolescent↗
PubMed1993

Stimulatory effect of Saireito on proopiomelanocortin gene expression in the rat anterior pituitary gland.

The effect of administration of Saireito, a Saiko agent, via a stomach cannula on adrenocorticotropin (ACTH) release and gene expression of proopiomelanocortin (POMC), the precursor for ACTH, in the anterior pituitary, as well as on the corticotropin-releasing factor (CRF) in the hypothalamus, was examined in pentobarbital anesthetized rats. Saireito decreased the hypothalamic CRF level due to an early release of CRF and stimulated ACTH release and POMC gene expression but did not increase CRF gene expression. These results suggest that Saireito does not stimulate CRF gene expression, although it does stimulate CRF release, which in turn stimulates POMC gene expression in the anterior pituitary and ACTH release.

Adrenocorticotropic Hormone↗
PubMed1993

A developmental pathway involving four phenotypically and functionally distinct subsets of CD3-CD4-CD8- triple-negative adult mouse thymocytes defined by CD44 and CD25 expression.

We have subdivided mouse CD4-CD8-CD3- triple-negative (TN) thymocytes into four subsets based upon expression of CD44 and CD25, including CD44+CD25-, CD44+CD25+, CD44-CD25+ and CD44-CD25-. Characterization of these cells revealed several features distinct to each subset, in particular the expression of high levels of c-kit (the receptor for stem cell factor) by CD44+CD25-TN and CD44+CD25+TN but not by CD44-CD25+TN and CD44-CD25-TN. The CD44+CD25+TN subset also included the IL-7 and stem cell factor-responsive cells, whereas only minimal responsiveness was observed by the CD44- populations. These subsets also showed differential cytokine production potential (CD44+CD25- > CD44+CD25+ > CD44-CD25+ > CD44-CD25-) after stimulation with calcium ionophore, PMA and IL-1. The repopulation potential of these subsets in 2-deoxyguanosine-treated fetal thymic lobes supports the following maturation sequence: CD44+CD25- -->CD44+CD25+ -->CD44-CD25+ -->CD44-CD25-. Furthermore, the sequence of progression from CD44+CD25+ to CD44-CD25+ cells was confirmed by their TCR beta-chain gene configuration. The former population exhibits germ-line TCR beta-chain configuration, whereas the latter subset shows a rearranged pattern.

Animals↗
PubMed1993

Sequential analysis of hematopoietic reconstitution achieved by transplantation of hematopoietic stem cells.

We confirmed that murine hematopoietic stem cells express the c-kit molecule but not lymphohematopoietic lineage markers. These lineage marker-negative c-kit-positive (Lin- c-kit+) cells were further divided according to the uptake of rhodamine-123 (Rh-123). Approximately 1,000 Lin- c-kit+ rhodamine-123dull cells, which contained 4.0 +/- 1.3 and 12.5 +/- 1.9 day 8 and day 12 spleen colony-forming units (CFU-S), respectively, rescued the 100% of lethally irradiated mice. One third of these cells formed colonies in the presence of interleukin-3 plus erythropoietin. The time course of the hematopoietic reconstitution of this primitive hematopoietic stem cell fraction was investigated by using Ly-5 congenic mice. Although myeloid cells and B lymphocytes were detected in the peripheral blood 2 to 3 weeks after transplantation, T lymphocytes were not detected until 4 weeks after transplantation. It is generally assumed that myeloid cells and B lymphocytes grow in the bone marrow and that T lymphocytes must pass through the thymus. For the first 2 to 3 weeks after transplantation, donor-type T lymphocytes were not dominant in the thymus, and most donor type cells were CD4/CD8 double-negative or double-positive (including CD4low and CD8low). Four weeks after transplantation, donor-type T lymphocytes were dominant and the ratio of CD4/CD8 cells had recovered to the normal pattern. However, significant numbers of T lymphocytes were detected in the peripheral blood at this stage. Sequential analysis of hematopoietic reconstitution from primitive stem cells demonstrates that myeloid and B-lymphoid lineages occurred earlier than that of the T-lymphoid lineages.

Animals↗
PubMed1993

Origin, differentiation, and repertoire selection of CD3+CD4-CD8- thymocytes bearing either alpha beta or gamma delta T cell receptors.

It has been widely accepted that CD3+CD4-CD8- T cells expressing TCR-alpha beta or TCR-gamma delta (found in the thymus as well as in the periphery) represent lineages distinct from either CD4+CD8- and CD4-CD8+ single-positive T cells expressing TCR-alpha beta. However, the origin, differentiation pathway, and TCR-repertoire selection of CD3+CD4-CD8- T cells remain controversial. We demonstrate that CD3+CD4-CD8- thymocytes can be separated into three subsets based on their expression of heat-stable Ag (HSA) and CD44. Our results further suggest the following: 1) the HSA+ subset represents a pre-selection population, although the HSA- subset is a postselection subset; 2) the high incidence of V beta 8.2 usage among CD3+CD4-CD8- thymocytes is a result of positive selection, rather than a predetermined event at a precursor cell level; 3) the maturation of CD3+CD4-CD8- thymocytes proceeds along the following differentiation pathway: HSA+CD44(-)-->HSA-CD44(-)-->HSA-CD44+. Both TCR-alpha beta +CD4-CD8- and TCR-gamma delta +CD4-CD8- thymocytes show similar differentiation processes; 4) CD3+CD4-CD8-cells directly differentiate from CD25+CD3-CD4-CD8- thymocytes which include precursor cells for both the CD3+CD4-CD8- and the CD4+CD8-/CD4-CD8+ lineages. Taken together, these results suggest that the CD25+CD3-CD4-CD8- stage of thymocyte differentiation represents a branching point for either the CD4+CD8- or CD4-CD8+ single-positive lineages or the CD3+CD4-CD8- lineages.

Animals↗
PubMed1993

New resorption assay with mouse osteoclast-like multinucleated cells formed in vitro.

We previously reported a procedure to obtain a preparation containing a large number of mouse osteoclast (OCL)-like multinucleated cells (MNCs) formed in cocultures of mouse osteoblastic and bone marrow cells in the presence of 1 alpha,25-dihydroxyvitamin D3 [1 alpha,25-(OH)2D3]. The MNCs satisfied major criteria of OCLs, such as tartrate-resistant acid phosphatase (TRAP) activity, acid production, calcitonin (CT) receptors, and the ability to form resorption pits on bone slices. In this report, we describe a simple resorption assay system using MNC preparations. After culturing MNC preparations or disaggregated rat OCL preparations on dentin slices, they were stained with Mayer's hematoxylin. The stained area corresponded exactly with the resorption pits visualized by scanning electron microscopy and were measured using an image analysis system attached to a light microscope. Pit formation by MNCs was gradually enhanced by reducing the medium pH (pH 7.5 < 7.2 < 6.9). The plan area resorbed by MNCs increased linearly for up to 72 h. These results are very similar to those obtained with OCL preparations. In multiple standard assays with MNC preparations, more than 250 MNCs could be placed on a dentin slice, and the total area resorbed to a level of up to 9% of the whole surface within 48 h. In contrast, in multiple assays with OCL preparations, it was not easy to place more than 50 OCLs on a slice and the resorbed area was only 0.7% of the surface.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid Phosphatase↗
PubMed1993

Neuropeptide Y increases the corticotropin-releasing factor messenger ribonucleic acid level in the rat hypothalamus.

Neuropeptide Y (NPY) has a stimulatory effect on adrenocorticotropin (ACTH) and corticotropin-releasing factor (CRF) release. In the present study, to investigate the effect of NPY on CRF synthesis, the effect of centrally administered NPY on CRF messenger RNA (mRNA) levels in rat hypothalamus was examined under pentobarbital anesthesia. The administration of 0.01, 0.1 and 1 nmol of NPY into the lateral ventricle dose-dependently Increased the plasma ACTH levels, as well as the levels of proopiomelanocortin mRNA in the anterior pituitary. The CRF mRNA level in the hypothalamus also increased after administration of 0.1 and 1 nmol of NPY in a dose-dependent manner. The administration of 3 nmol of phentolamine or propranolol failed to block 0.1 nmol NPY-induced ACTH release or 1 nmol NPY-stimulated CRF mRNA levels in the hypothalamus. These results Indicate that the central administration of NPY increases the CRF mRNA levels in the hypothalamus and the probable CRF release, which increases the proopiomelanocortin mRNA levels and ACTH secretion in the anterior pituitary. Therefore, NPY seems to play a physiological role in the regulation of the release and synthesis of CRF in the hypothalamus.

Adrenocorticotropic Hormone↗
PubMed1993

Carbohydrate structures of human alpha-fetoprotein of patients with hepatocellular carcinoma: presence of fucosylated and non-fucosylated triantennary glycans.

Chemical structures of the sugar chains of various human alpha-fetoprotein (AFP) species with different affinity for Concanavalin A (Con A) and Lens culinaris agglutinin (LCA) were examined by pyridylamination of their oligosaccharides and stepwise exoglycosidase digestion. Using reversed-phase and size-fractionation high performance liquid chromatography systems we identified six pyridylamino-sugar chains. The Con A-reactive and LCA-nonreactive species of AFP from patients with hepatocellular carcinoma contained a biantennary sugar chain, and the Con A-reactive and LCA-reactive species had a biantennary one with a fucose residue at the innermost N-acetylglucosamine residue. The Con A-nonreactive and LCA-reactive species contained a biantennary sugar chain both with a bisecting-N-acetylglucosamine residue at the trimannosyl core and with a focus residue at the innermost N-acetylglucosamine residue. The Con A-nonreactive and LCA-nonreactive species contained a fucosylated triantennary sugar chain as a major component, and two minor components: a triantennary sugar chain and a biantennary sugar chain with a bisecting-N-acetylglucosamine residue at the trimannosyl core. Thus, the fucosylated and non-fucosylated triantennary sugar chains were newly identified in human AFP. Essentially identical results were obtained for AFP from the patient with gallbladder carcinoma which metastasizes to the liver. These results indicate that the increment in fucosylation and branching to form new antennae is a characteristic feature of the carbohydrate chains of AFP from patients with neoplastic diseases of the liver.

Carbohydrate Conformation↗
PubMed1993

The fetal thymus stores immature hemopoietic cells capable of differentiating into non-T lineage cells constituting the thymus stromal element.

Immature hemopoietic cell lines were established by transforming fetal thymocytes in vitro with a ts mutant of Abelson murine leukemia virus. They are positive for c-kit and IL-2R alpha but negative for lineage specific markers. Their TCR and Ig heavy chain genes are in germline configuration, and are expressed as germline gene transcripts. When these cell lines were stimulated in vitro with IL-1 their morphology changed into that of typical macrophages (M phi). Subsequent analysis of a particular clone, which displayed the morphological change at the highest efficiency among established cell lines, indicated that the clone possesses the capacity to differentiate into I-A-M phi capable of secreting several cytokines, and supporting the proliferation of fetal and adult thymocytes in vitro. If their surface markers are considered, their normal counterparts would be present in a minor subset of CD4-CD8- double-negative cells in the thymus in early development. The results raise the possibility that the thymic organ at an early stage of development stores immature hemopoietic cells capable of differentiating into a non-T lineage constituting the thymic stromal elements.

Abelson murine leukemia virus↗