Publications by authors named "Dong Ku Kim"

Immunological approaches are gaining attention as a convenient and economical method for sex-sorting mammalian spermatozoa. A monoclonal antibody (WholeMom™) has previously been reported to cause agglutination of Y-chromosome-bearing spermatozoa in frozen-thawed semen for gender preselection. However, its usefulness for gender preselection in fresh semen and subsequent in vitro fertilization (IVF) after freeze-thawing has not been reported.

View Article and Find Full Text PDF

Treatment of donor cells and/or cloned embryos with cytidine analogues, having an Aza group at its 5th carbon (5-Aza), such as 5-Azacytidine (5-Aza-C) or 5-Aza-2'-deoxycytidine (5-Aza-dC) improves the in vitro development of cloned embryos produced by somatic cell nuclear transfer (SCNT). In vitro maturation (IVM) of immature pig oocytes treated with 5-Aza-C not only results in greater (P < 0.05) meiotic maturation to the MII stage but also enhances the capacity of 5-Aza-C treated oocytes for early embryonic development after parthenogenetic activation (PA), in vitro fertilization (IVF) or SCNT in a dose-dependent manner (0-10 μM).

View Article and Find Full Text PDF

The triggering receptor expressed on myeloid cells (TREM) family, which is abundantly expressed in myeloid lineage cells, plays a pivotal role in innate and adaptive immune response. In this study, we aimed to identify a novel receptor expressed on hematopoietic stem cells (HSCs) by using in silico bioinformatics and to characterize the identified receptor. We thus found the TREM-like transcript (TLT)-6, a new member of TREM family.

View Article and Find Full Text PDF

Introduction: As a consequence of poor productivity caused by a long anoestrous period, considerable research effort has been given to oestrus induction in dogs to enhance the productivity of young dogs and to preserve breeds.

Materials And Methods: Oestrus was induced in 30 anoestrous bitches more than three months after the last oestrus. Bitches orally received fermented rice punch with or without bromocriptine once daily for 21 consecutive days.

View Article and Find Full Text PDF

Background: This study was attempted to identify new molecules expressed on the plasma membrane of human umbilical vein endothelial cells (HUVECs) using monoclonal antibody-based proteomics technology and to determine the effect of the identified antibody on vascular reactivity.

Methods: Twenty-two antibodies were developed from rats inoculated with HUVECs, and their effects were determined by observing vascular reactivity.

Results: Among the 22 antibodies, the C-7 antibody significantly inhibited endothelium-dependent vasorelaxation in response to acetylcholine (ACh) but not to histamine.

View Article and Find Full Text PDF

Mesenchymal stem cells (MSCs) have known to induce immunosuppressive properties by preventing T cell proliferation. However, it is remains unclear how MSCs inhibit T cell proliferation. To identify the factor that inhibits T cell proliferation, we conducted a cytokine array analysis of culture medium from a co-culture of MSCs and T cells and found that the chemokines, CXCL1, 2 and 3, were induced in T cells.

View Article and Find Full Text PDF

HoxB4, a homeodomain-containing transcription factor, is involved in the expansion of hematopoietic stem cells and progenitor cells in vivo and in vitro, and plays a key role in regulating the balance between hematopoietic stem cell renewal and cell differentiation. However, the biological activity of HoxB4 in other cells has not been reported. In this study, we investigated the effect of overexpressed HoxB4 on cell survival under various conditions that induce death, using the Ba/F3 cell line.

View Article and Find Full Text PDF

We examined whether deficiency of the GGTA1 gene in pigs altered the expression of several glycosyltransferase genes. Real-time RT-PCR and glycosyltransferase activity showed that 2 sialyltransferases [α2,3-sialyltransferase (α2,3ST) and α2,6-sialyltransferase (α2,6ST)] in the heterozygote GalT KO liver have higher expression levels and activities compared to controls. Enzyme-linked lectin assays indicated that there were also more sialic acid-containing glycoconjugate epitopes in GalT KO livers than in controls.

View Article and Find Full Text PDF

Background: Although the graft-versus-tumor (GVT) effect of donor-derived T cells after allogeneic hematopoietic stem cell transplantation has been used as an effective adoptive immunotherapy, the antitumor effects of cord blood (CB) transplantation have not been well studied.

Methods: We established the animal model by transplantation of CB mononuclear cells and/or tumor cells into NOD/SCID mice. The presence of CB derived T cells in NOD/SCID mice or tumor tissues were determined by flow cytometric and immunohistochemical analysis.

View Article and Find Full Text PDF

Doxorubicin (DOX) is involved in the induction of DNA damage, inhibition of cell proliferation, impairment of mitochondria, and cell death. To determine the biological effects of DOX in murine lymphocytes, we analyzed cell proliferation, cell cycle status, and apoptosis in Ba/F3 and EL4 lymphoid cells. DOX treatment resulted in significant cellular morphological alteration with increased intracellular granularity and cell size.

View Article and Find Full Text PDF

Cross-linking of CD137 ligand (CD137L), a member of the TNF family, with recombinant CD137-Fc (rCD137-Fc) protein enhanced adherence of bone marrow-derived macrophages, and increased the expression of ICAM-1, IL-1beta, IL-6, M-CSF and phosphotyrosine proteins. In RAW264.7 cells, a murine myeloid cell line, rCD137-Fc not only increased adherence but also cell multiplication, in a manner comparable to LPS or M-CSF.

View Article and Find Full Text PDF

OCT4 plays a crucial role in pluripotency and self-renewal of embryonic stem cells. OCT4 is also expressed in testicular germ cell tumors (GCTs), suggesting the important function of OCT4 as an oncogenic factor in GCTs. To understand the molecular mechanism of human OCT4 (hOCT4) in tumorigenesis as well as stemness, we identified hOCT4 transactivation domains in human embryonic carcinoma cells.

View Article and Find Full Text PDF

Genetic modification of hematopoietic stem cells holds great promise in the treatment of hematopoietic disorders. However, clinical application of gene delivery has been limited, in part, by low gene transfer efficiency. To overcome this problem, we investigated the effect of retronectin (RN) on lentiviral-mediated gene delivery into hematopoietic progenitor cells (HPCs) derived from bone marrow both in vitro and in vivo.

View Article and Find Full Text PDF

The core embryonic stem cell transcription factors Oct4, Sox2, and Nanog are expressed in germ cell tumors (GCTs) and have been proposed to play a regulatory role in tumorigenesis. However, little is known about the mechanism of regulation of tumorigenesis by the complicated network of these proteins. Nanog is a novel homeobox-containing transcription factor that is expressed in pluripotent cells as well as GCTs.

View Article and Find Full Text PDF

Objective: To develop an efficient freezing method suitable for large-scale cryopreservation of human embryonic stem cells (hESCs).

Design: Experimental study.

Setting: Research institute.

View Article and Find Full Text PDF

We isolated a stem cell subpopulation from human lung cancer A549 cells using FACS/Hoechst 33342. This side population (SP), which comprised 24% of the total cell population, totally disappeared after treatment with the selective ABCG 2 inhibitor fumitremorgin C. In a repopulation study, isolated SP and non-SP cells were each able to generate a heterogeneous population of SP and non-SP cells, but this repopulation occurred more rapidly in SP cells than non-SP.

View Article and Find Full Text PDF

Polystyrene derivatives, poly[N-pvinylbenzyl-O-D-glucopyranosyl-(1-4)-D-glucoamide] (PV Maltose) and poly[N-p-vinylbenzyl-O-mannopyranosyl-(1-4)-D-glucoamide] (PV Mannose), which contain glucose and mannose moieties, respectively, have the specific binding ability with murine hematopoietic cells. In this study, we confirm the ability of these glycopolymers to interact specifically with human hematopoietic stem cells (HSCs) and mature cells derived from human cord blood (CB) and peripheral blood (PB). Using fluorescence isothiocyanate (FITC)-labeled glycopolymers, we observed that 98% to 93% of hematopoietic cells interacted very strongly with PV Mannose, and 63% of CB and 29% PB interacted with PV Maltose.

View Article and Find Full Text PDF

Background: The studies on cancer-stem-cells (CSCs) have attracted so much attention in recent years as possible therapeutic implications. This study was carried out to investigate the gene expression profile of CSCs in human lung adenocarcinoma A549 cells.

Results: We isolated CSCs from A549 cell line of which side population (SP) phenotype revealed several stem cell properties.

View Article and Find Full Text PDF

Extracellular nucleotides have multiple biological actions in processes such as proliferation, differentiation, chemotaxis, and cytokine secretion through P2X receptors on the cell surface. To determine the biological activity of adenosine triphosphate (ATP) and the expression of P2 nucleotide receptors in murine bone marrow-derived hematopoietic cells and stem cells/progenitor cells, we investigated the effects of ATP in assays of cell proliferation and cell death in vitro. Our results demonstrated that several subtypes of P2X receptors were expressed on hematopoietic cells and that P2X7, in particular, was partially expressed in hematopoietic stem cells/progenitor cells.

View Article and Find Full Text PDF

CD4 is a cell surface glycoprotein that acts as a co-receptor for the T cell antigen receptor by binding to a non-polymorphic portion of MHC molecules. CD4 also functions as a receptor for human immunodeficiency virus type-I (HIV-1) because the viral envelope glycoprotein gp120 binds to CD4 with a high affinity. We have previously demonstrated that introduction of mutations into CD4 abolished the binding of gp120 and prevented HIV-1 from entering cells and spreading.

View Article and Find Full Text PDF

Poly[N-pvinylbenzyl-O-D-galactopyranosyl-(1-4)-D-glucoamide], poly[N-pvinylbenzyl-O-D-glucopyranosyl-(1-4)-D-glucoamide], and poly[N-p-vinylbenzyl-O-mannopyranosyl-(1-4)-D-gluconamide] (referred to as PVLA, PVMA, and PV-Man) are polystyrene derivatives that contain galactose, glucose, and mannose moieties, which interact with hematopoietic cells (HCs). To clarify the specific interaction between the glucopolymers and hematopoietic cells, glycopolymers labeled with fluorescent isothiocyanate (FITC) were used to follow the specific interaction, which was visualized by confocal laser microscopy. We found that PV-Man binds strongly to HCs, probably because of a specific interaction mediated by specific receptors present on the cell membrane, while some cytotoxicity when was observed when PV-Man interacted with the cell membrane.

View Article and Find Full Text PDF

Oct4 encodes a transcription factor that is involved in the maintenance of self-renewal in stem cells. Recently, the molecular mechanisms that regulate Oct4 expression have come under investigation. In this study, we demonstrate that the orphan nuclear receptor steroidogenic factor-1 (SF-1) behaves as a transcriptional activator of human Oct4 (hOct4) through direct interaction with a SF-1 binding element in the hOct4 proximal promoter.

View Article and Find Full Text PDF

Extracellular adenosine 5'-triphosphate (ATP) affects the function of many tissues and cells. To confirm the biological activity of ATP on human myeloid leukemic cells, F-36P and HL-60, cells were treated with a variety of concentrations of ATP. The stimulation with extracellular ATP induced the arrest of cell proliferation and cell death from the analysis of Annexin-V staining and caspase activity by flow cytometry.

View Article and Find Full Text PDF

A 25-kDa linear polyethylenimine (25 kDa L-PEI) has proven to be efficient and versatile agent for gene delivery. Therefore, we determined the optimal transfection conditions of 25 kDa L-PEI and examined whether it has comparable transfection efficiency with other commercially available reagents, ExGen 500, LipofectAMINE 2000, and Effectene by using EGFP expression vector in different cell lines. Transfection efficiency and cytotoxicity were measured by flow cytometry.

View Article and Find Full Text PDF

We investigated nuclear localization signal (NLS) determinants within the AT-hook and ETS DNA-binding domains of murine Elf3 (mElf3), a member of the subfamily of epithelium-specific ETS transcription factors. Deletion mutants containing the AT-hook, ETS domain or both localized strictly in the nucleus, suggesting that these individual domains contain independent NLS motif(s). Within the AT-hook domain, four basic residues (244KRKR247) were critical for strong NLS activity, and two potent bipartite NLS motifs (236-252 and 249-267) were sufficient for nuclear import of mElf3, although less efficient than the full domain.

View Article and Find Full Text PDF