• Title/Summary/Keyword: cell fusion

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Comparison of Microtubule Distributions between Somatic Cell Nuclear Transfer and Parthenogenetic Porcine Embryos

  • Park, Joo-Hee;Kwon, Dae-JinK;Lee, Beom-Ki;Hwang, In-Sun;Park, Choon-Keun;Yang, Boo-Keun;Cheong, Hee-Tae
    • Reproductive and Developmental Biology
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    • v.33 no.1
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    • pp.13-18
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    • 2009
  • The aim of this study was to examine the microtubule distributions of somatic cell nuclear transfer (SCNT) and parthenogenetic porcine embryos. Porcine SCNT embryos were produced by fusion of serum-starved fetal fibroblast cells with enucleated oocytes. Reconstituted and mature oocytes were activated by electric pulses combined with 6-dimethlyaminopurine treatment. SCNT and parthenogenetic embryos were cultured in vitro for 6 days. Microtubule assembly of embryos was examined by confocal microscopy 1 hr and 20 hr after fusion or activation, respectively. The proportions of embryos developed to the blastocyst stage were 25.7% and 30.4% in SCNT and parthenogenetic embryos, respectively. The frequency of embryos showing $\beta$-tubulins was 81.8% in parthenogenetic embryos, whereas 31.3% in SCNT embryos 1 hr after activation or fusion. The frequency of the embryos underwent normal mitotic phase was low in SCNT embryos (40.6%) compared to that of parthenogenetic ones (59.7%) 20 hr after fusion or activation (p<0.05). The rate of SCNT embryos with an abnormal mitosis pattern is about twice compared to that of parthenogenetic ones. The spindle assembly and its distribution of SCNT embryos in the first mitotic phase were not different from those of parthenogenetic ones. The result shows that although microtubule distribution of porcine SCNT embryos shortly after fusion is different from parthenogenetic embryos, and the frequency of abnormal mitosis 20 hr after fusion or activation is slightly increased in SCNT embryos, microtubule distributions at the first mitotic phase are similar in both SCNT and parthenogenetic embryos.

Porosome: the Universal Molecular Machinery for Cell Secretion

  • Jena, Bhanu P.
    • Molecules and Cells
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    • v.26 no.6
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    • pp.517-529
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    • 2008
  • Porosomes are supramolecular, lipoprotein structures at the cell plasma membrane, where membrane-bound secretory vesicles transiently dock and fuse to release inravesicular contents to the outside during cell secretion. The mouth of the porosome opening to the outside, range in size from 150 nm in diameter in acinar cells of the exocrine pancreas, to 12 nm in neurons, which dilates during cell secretion, returning to its resting size following completion of the process. In the past decade, the composition of the porosome, its structure and dynamics at nm resolution and in real time, and its functional reconstitution into artificial lipid membrane, have all been elucidated. In this mini review, the discovery of the porosome, its structure, function, isolation, chemistry, and reconstitution into lipid membrane, the molecular mechanism of secretory vesicle swelling and fusion at the base of porosomes, and how this new information provides a paradigm shift in our understanding of cell secretion, is discussed.

The Functional Role of Maturation Promoting Factor in the Two-cell Embryos (생쥐 2-세포기 배아에서 성숙유도물질의 기능적 역할)

  • 강해묵;이대기
    • The Korean Journal of Zoology
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    • v.36 no.2
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    • pp.277-284
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    • 1993
  • A possible involvement of maturation promoting factor (nfPF) in the two-cell block phenomenon was studied by fusion experiments. Germinal vesicle (GlF) ooeyte was fused with a blastomore from late or blocked 2-cell mouse embryos. and germinal vesicle breakdoum (GVBD) of fused GV oocvtes in the presence of dbcAMP (100$\mu$g/ml) was scored as an index of MPF aniviD. GnD was induced approximately 30% by fusion of a blastomere derived from late 2-cell embryos, but not from blocked 2-cell embryos. The rate of GVBD was changed when GV oocyte was fused with a blastomere from late 2-cell embryos which were treated with u-amanitin, puromvcin or colcemid before and after hsion: Treatment of late 2-cell embryos with puromycin (50 Is/mll but not with u-amanitin (100 Is/ml) clearly inhibited GVBD, indicating that do novo protein synthesis maw be required for the appearance of MPF activity in late 2-cell embryos. Treatment of late 2-cell embryos w기h colcemid (0.1 Is/mll doubled GVBD, presumably due to the maintenance of metaphase or mitotic phase. SDS-PAGE and twoiimensional electrophoresis revealed that there was no difference in protein synthetic pattern in late and blocked 2-cell embryos, but three phosphoproteins with 27, 35 and 46 M)a, presumsblv M-phase components were phosphorylated in late 2-cell embryos but not in blocked 2-cell embryos. It seems then that MPF activity is closely related to phosphorylstion of M-phase components in late 2-cell embryos.

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Expression Analysis of the Ligand to Ly-6E.1 Mouse Hematopoietic Stem Cell Antigen

  • Hwang, Dae-Youn;Min, Dul-Lei;Sonn, Chung-Hee;Chang, Mi-Ra;Lee, Mi-Hyun;Paik, Sang-Gi;Kim, Young-Sang
    • Animal cells and systems
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    • v.1 no.1
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    • pp.157-164
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    • 1997
  • Ly-6E.1 antigen was proposed as a regulatory molecule of T lymphocyte activation, a hematopoietic stem cell marker, a memory cell marker, and an adhesion molecule. Though there were several reports suggesting the presence of Ly-6 ligand, the characterization of the ligand was not yet performed, As an attempt to screen the expression of Ly-6E.1 ligand, we prepared a probe for detecting Ly-6E.1 ligand by producing a fusion protein between Ly-6E.1 and $hlgC_{r1}$, A mammalian cell expression vector with Ly-6E.$1/hlgC_{r1}$ chimeric cDNA was transfected in SP2/0-Ag14 myeloma cells, and stable transfectants were selected. The fusion protein was produced as a dimer and maintained the epitopes for monoclonal antibodies specific for Ly-6E.1 and for anti-human lgG antibody. The purified fusion protein through Gammabind G column was used for FACS analyses for the expression of Ly-6E.1 ligand. The fusion protein interacted with several cell lines originating from B cells, T cells, or monocytes. The fusion Protein also strongly stained bone marrow, lymph node, and spleen cells, but thymic cells weakly, if any. The staining was more obvious in C57BL/6 $(Ly-6^b)$ than Balb/c $(Ly-6^a)$ mice. These results suggest that the interaction of Ly-6E.1 with Ly-6E.1 ligand may function both in the stem cell environment and in the activation of mature lymphocytes. The fusion protein may be a valuable tool in characterization of biochemical properties of the Ly-6E.1 ligand and, further, in isolating its cDNA.

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Study on In Vitro Development of Mouse Embryos (생쥐 수정란의 핵이식후 체외발달에 관한 연구)

  • 박희성;이효종;최상용;박충생
    • Korean Journal of Animal Reproduction
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    • v.14 no.3
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    • pp.205-211
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    • 1990
  • Single nuclei from two-, four- and eight-cell mouse embryos were transplanted into enucleated two-cell mouse embryos by micromanipulation and sendai virum mediated fusion. no significant difference in successful injectin rate and fusion rate was found between the cell stages of nuclear donor embryos. There nuclear transplant embryos receiving different cell stage nuclei were cultured in vitro for 96 hours. 75.3% of 255 embryos receiving 2-cell nuclei, 68.2% of 236 embryos reciving 4-cell nuceli and 46.9% of 228 embryos receiving 8-cell nuclei were developed to blastocyst, respectively. The number of blastomeres was significantly(P<0.05) reduced in the embryos receiving 8-cell nuclei, compared with the embryos receiving 2-cell, 4-cell nuclei or the intact embryos. Also the size of blastocysts was significantly(P<0.05) smaller in the embryos receiving 8-cell nuclei, compared with the intact or other nuclear transplant embryos. These results suggest that single nuclei introduced into the enucleated two-cell embryos are able to support the in vitro development of the reconstituted embryos to blastocysts. The prominant retardation of blastocoele formation and cell division was shown in nuclear transplant embryos receiving eight-cell nuclei when they were cultured in vitro.

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A Study on the production of Monoclonal Antibodies against Rhodotrodula rubra (효모양진균의 단크론 생성)

  • Ryeom K.;Kim S. C.;Lee J. H.
    • Journal of environmental and Sanitary engineering
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    • v.4 no.1 s.6
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    • pp.17-28
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    • 1989
  • Having studied the production of monoclonal antibodies for developing a diagnosis medicine which shall be detected by a high-sensitivity test by using Rhodotorula rubra as a fungi-host which had been extracted through biochemical tests and follow-up examinations on Yeast-like fungi obtained from pulmonary tissues of pulmonary tuberculosis patients who had been in Kong ju National Tuberculosis Hospital from Jun. to Dec. in 1987, I. have gained such results as follows: 1. The fusion rate was influenced by feeder cell layers, cell density and time required to the cell fusion with cells in myelona subculture. 2. The fusion rate did not show any significant difference when the cell was applyed with two molecular weights, i.e., 1500 and 4000, of polyethylene glycol. 3. Fused cells after the addition of HAT selection media were bright and round, whereas unfused myelona cells and spleen cells were shrunk and granulated. 4. The cell fusion rate turned out to be about $57.2\%$(150 wells / 264 wells). 5. $10\%$(15 wells / 150 wells) of the positive reaction was detected in monoclonal antibody screening. 6. The titer which had reacted positively to Rhodotorula rubra fungal-host was 800 times in density after the gradual dilution of the produced monoclonal antibodies with Indirect ELISA method. 7. The Strongest specific reaction came out after the peroxidase labelled anti-human Immunogobulin had been applyed to Rhodotorula rubra for activating its nature after making drift with Carbonate-bicarbonate buffer (pH 9.6) and drying completely.

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Propofol promotes osteoclastic bone resorption by increasing DC-STAMP expression

  • Kim, Eun-Jung;Kim, Hyung Joon;Baik, Seong Wan;Kim, Kyung-Hoon;Ryu, Sie Jeong;Kim, Cheul-Hong;Shin, Sang-Wook
    • Journal of Dental Anesthesia and Pain Medicine
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    • v.18 no.6
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    • pp.349-359
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    • 2018
  • Background: Propofol is an intravenous anesthetic which has antioxidant effects due to its similarity in molecular structure to ${\alpha}$-tocopherol. It has been reported that ${\alpha}$-tocopherol increases osteoclast fusion and bone resorption. Here, we investigated the effects of propofol on signaling pathways of osteoclastogenic gene expression, as well as osteoclastogenesis and bone resorption using bone marrow-derived macrophages (BMMs). Methods: BMMs were cultured with macrophage colony-stimulating factor (M-CSF) alone or M-CSF plus receptor activator of nuclear factor kappa B ligand (RANKL) in the presence of propofol ($0-50{\mu}M$) for 4 days. Mature osteoclasts were stained for tartrate-resistant acid phosphatase (TRAP) and the numbers of TRAP-positive multinucleated osteoclasts were counted. To examine the resorption activities of osteoclasts, a bone resorption assay was performed. To identify the mechanism of action of propofol on the formation of multinucleated osteoclasts, we focused on dendritic cell-specific transmembrane protein (DC-STAMP), a protein essential for pre-osteoclastic cell fusion. Results: Propofol increased the formation of TRAP-positive multinucleated osteoclasts. In addition, the bone resorption assay revealed that propofol increased the bone resorption area on dentin discs. The mRNA expression of DC-STAMP was upregulated most strongly in the presence of both RANKL and propofol. However, SB203580, a p38 inhibitor, significantly suppressed the propofol/RANKL-induced increase in mRNA expression of DC-STAMP. Conclusion: We have demonstrated that propofol enhances osteoclast differentiation and maturation, and subsequently increases bone resorption. Additionally, we identified the regulatory pathway underlying osteoclast cell-cell fusion, which was enhanced by propofol through p38-mediated DC-STAMP expression.

Effect of Cell Cycle Stage on the Development of Embryos Produced by Cumulus Cell Nuclear Transfer in Hanwoo (Korean Cattle)

  • Im, G.S.;Yang, B.S.;Yang, B.C.;Chang, W.K.;Yi, Y.J.;Park, C.S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.14 no.6
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    • pp.759-764
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    • 2001
  • This study was carried out to investigate the effect of activation timing, cell cycle and passage on the development of embryos produced by cumulus cell nuclear transfer in Hanwoo (Korean cattle). Nuclear donor cumulus cells were cultured in Dulbecco's modified Eagle medium supplemented with 10% fetal bovine serum at $38.5^{\circ}C$ in a humidified atmosphere of 5% $CO_2$ in air. The 1~6 passages of serum deprived or actively dividing cumulus cells were isolated and used as donor cells. The in vitro matured oocytes were enucleated and then the isolated donor cells were introduced. One pulse of 180 volts for $15{\mu}s$ was applied to induce the fusion between karyoplast and cytoplast. The activation was done before or after the fusion. To activate, oocytes were treated with $10{\mu}M$ calcium ionophore for 5 min immediately followed by 2 mM 6-dimethylaminopurine for 3 h. The nuclear transfer embryos were cultured in $500{\mu}l$ of modified CRlaa supplemented with 3 mg/ml BSA in four well dish covered with mineral oil. After 3 days culture, culture medium was changed into modified CRlaa medium containing 1.5 mg/ml BSA and 5% FBS for 4 days. The incubation environment was 5% $CO_2$, 5% $O_2$, 90% $N_2$ at $38.5^{\circ}C$. There was no blastocyst formation when the nuclear transfer embryos were activated before the fusion, whereas, 29.9% of blastocyst formation was shown when the nuclear transfer embryos were activated after the fusion. When serum deprived and actively dividing cumulus cells were used as nuclear donor cells, the developmental rates to blastocyst were 38.5% and 40.6%, respectively. There was no significant difference between serum deprived and actively dividing cells in the developmental rates. The developmental rates to blastocyst according to 1~6 passages were 37.5~44.4%. However, there were no significant differences among passages. These results indicate that 1~6 passage cumulus cell irrespective of cell cycle could support development of nuclear transfer embryos activated after the fusion.

Pilot Symbol Assisted Weighted Data Fusion Scheme for Uplink Base-Station Cooperation System

  • Zhang, Zhe;Yang, Jing;Zhang, Jiankang;Mu, Xiaomin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.2
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    • pp.528-544
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    • 2015
  • Base Station Cooperation (BSC) has been a promising technique for combating the Inter-Cell Interference (ICI) by exchanging information through a high-speed optical fiber back-haul to increase the diversity gain. In this paper, we propose a novel pilot symbol assisted data fusion scheme for distributed Uplink BSC (UBSC) based on Differential Evolution (DE) algorithm. Furthermore, the proposed scheme exploits the pre-defined pilot symbols as the sample of transmitted symbols to constitute a sub-optimal Weight Calculation (WC) model. To circumvent the non-linear programming problem of the proposed sub-optimal model, DE algorithm is employed for searching the proper fusion weights. Compared with the existing equal weights based soft combining scheme, the proposed scheme can adaptively adjust the fusion weights according to the accuracy of cooperative information, which remains the relatively low computational complexity and back-haul traffic. Performance analysis and simulation results show that, the proposed scheme can significantly improve the system performance with the pilot settings of the existing standards.