• Title/Summary/Keyword: Cellular Formation

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Cyclopamine, an Antagonist of Hedgehog (Hh) Signaling Pathway, Reduces the Hatching Rate of Parthenogenetic Murine Embryos

  • Park, Jaehyun;Moon, Jeonghyeon;Min, Sol;Chae, Stephan;Roh, Sangho
    • Journal of Embryo Transfer
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    • v.33 no.4
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    • pp.237-243
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    • 2018
  • Hedgehog (Hh) pathway plays a key role in development from invertebrate to vertebrate. It is known to be involved in cell differentiation, polarity, proliferation, including the development of vertebrate limb and the establishment of flies' body plan. To investigate how the regulation of Hh pathway affects the development of parthenogenetic murine embryos, the parthenogenetically activated murine embryos were treated with either cyclopamine (Cyc), an antagonist of Hh pathway, or purmorphamine, an agonist of Hh pathway. While Cyc did not affect the blastocyst formation and its total cell number, the chemical reduced the hatching rate of embryos and the expression levels of Fn1 mRNA. The results of the present study show the possibility that Cyc may affect the development of embryos at blastocyst stage by blocking Hh pathway and this may cause detrimental effect to the embryos at peri-, and post-implantation stages.

Understanding of Cementum Formation by the Wnt/β-Catenin Signaling (Wnt/β-Catenin 신호조절에 의한 백악질 형성의 이해)

  • You, Young-Jae;Yang, Jin-Young
    • Journal of dental hygiene science
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    • v.16 no.6
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    • pp.401-408
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    • 2016
  • Periodontal disease is one of the major dental diseases. Currently, various methods are used for healing and successful regeneration of periodontal tissue damaged by periodontal disease. The periodontal ligament and alveolar bone have received considerable interest for use in periodontal tissue regeneration and induction. However, as the functions of the factors required for tooth attachment and key regulatory factors for periodontal tissue regeneration in the cementum have recently been identified, interest in cementum formation and regeneration has increased. Dental cementum forms in the late phase of tooth development because of the reciprocal regulatory interaction between cervical loop epithelial cells and surrounding mesenchymal cells, which is regulated by various gene signaling networks. Many attempts have been made to understand the regulatory factors and cellular and molecular mechanisms associated with new cementum formation. In this paper, we reviewed the study outcomes to date on the regulatory factors that induce cementum formation and regeneration, focusing on understanding the roles and functions of Wnt signaling in the regulation of cementum formation. In addition, we aimed to obtain information on the useful reciprocal regulatory factors that mediate cementum formation and regeneration through a series of molecular mechanisms.

Alteration in cellular acetylcholine influences dauer formation in Caenorhabditis elegans

  • Lee, Jeeyong;Kim, Kwang-Youl;Paik, Young-Ki
    • BMB Reports
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    • v.47 no.2
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    • pp.80-85
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    • 2014
  • Altered acetylcholine (Ach) homeostasis is associated with loss of viability in flies, developmental defects in mice, and cognitive deficits in human. Here, we assessed the importance of Ach in Caenorhabditis elegans development, focusing on the role of Ach during dauer formation. We found that dauer formation was disturbed in choline acetyltransferase (cha-1) and acetylcholinesterase (ace) mutants defective in Ach biosynthesis and degradation, respectively. When examined the potential role of G-proteins in dauer formation, goa-1 and egl-30 mutant worms, expressing mutated versions of mammalian $G_o$ and $G_q$ homolog, respectively, showed some abnormalities in dauer formation. Using quantitative mass spectrometry, we also found that dauer larvae had lower Ach content than did reproductively grown larvae. In addition, a proteomic analysis of acetylcholinesterase mutant worms, which have excessive levels of Ach, showed differential expression of metabolic genes. Collectively, these results indicate that alterations in Ach release may influence dauer formation in C. elegans.

Cytotoxicity of Vibrio vulnificus Cytolysin on Rat Neutrophils

  • Park, Kwang-Hyun;Rho, In-Whan;Park, Byung-Hyun;Kim, Jong-Suk;Kim, Hyung-Rho
    • BMB Reports
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    • v.32 no.3
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    • pp.273-278
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    • 1999
  • Cytolysin produced by Vibrio vulnificus has been known to be lethal to mice by increasing vascular permeability and neutrophil sequestration in the lung. In the present study, a cytotoxic mechanism of V. vulnificus cytolysin on the neutrophil was investigated. Cytolysin rapidly bound to neutrophils and induced cell death, as determined by the trypan blue exclusion test. V. vulnificus cytolysin caused the depletion of cellular ATP without the release of ATP or lactate dehydrogenase. Formation of transmembrane pores was evidenced by the rapid efflux of potassium and 2-deoxy-D-[$^3H$]glucose from cytolysin-treated neutrophils. It was further confirmed by the rapid flow of monovalent ions in the patch clamp of cytolysin-treated neutrophil membrane. The pore formation was accompanied by the oligomerization of cytolysin monomers on the neutrophil membrane as demonstrated by immunoblot, which exhibited a 210 kDa band corresponding to a tetramer of the native cytolysin of $M_r$ 51,000. These findings indicate that V. vulnificus cytolysin rapidly binds to the neutrophil membrane and oligomerizes to form small transmembrane pores, which induce the efflux of potassium and the depletion of cellular ATP leading to cell death without cytolysis.

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Essential Role of brc-2 in Chromosome Integrity of Germ Cells in C. elegans

  • Ko, Eunkyong;Lee, Junho;Lee, Hyunsook
    • Molecules and Cells
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    • v.26 no.6
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    • pp.590-594
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    • 2008
  • brc-2, an ortholog of BRCA2 in Caenorhabditis elegans, is essential in the maintenance of genetic integrity. In C. elegans, cellular location correlates with meiotic progression, and transgene-induced cosuppression is observed in the germ line but not in somatic cells. We used these unique features to dissect the role of brc-2 in the germ line from that in somatic cells. In situ hybridization of wild type animals revealed that brc-2 gene expression was higher in oocytes than in other germline cells, and was barely detectable in mitotic cells. In contrast, germ cells containing multicopies of the brc-2 transgene showed no significant in situ hybridization signal at any oogenesis stage, confirming that brc-2 expression was functionally cosuppressed in the transgenic germ line. RAD-51 foci formation in response to DNA damage was abrogated in brc-2-cosuppressed germ cells, whereas wild-type germ cells showed strong RAD-51 foci formation. These germ cells exhibited massive chromosome fragmentation and decompaction instead of six bivalent chromosomes in diakinesis. Accordingly, lethality was observed after the early stage of germline development. These results suggest that brc-2 plays essential roles in chromosome integrity in early prophase, and therefore is crucial in meiotic progression and embryonic survival.

Efficient Production of Parthenogenetic Murine Embryonic Stem Cells by the Treatment of Pluripotin (SC-1) (Pluripotin(SC-1) 처리를 통한 단위발생 마우스 배아줄기세포 생산 효율 향상)

  • Kang, Hoin;Roh, Sangho
    • Journal of Embryo Transfer
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    • v.27 no.3
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    • pp.171-174
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    • 2012
  • Various small molecules can be used to control major signaling pathways to enhance stemness and inhibit differentiation in murine embryonic stem cell (mESC) culture. Small molecules inhibiting the fibroblast growth factor (FGF)/ERK pathway can preserve pluripotent cells from stimulation of differentiation. In this study, we aimed to evaluate the effect of pluripotin (SC-1), an inhibitor of the FGF/ERK pathway, on the colony formation of outgrowing presumptive mESCs. After plating the zona pellucida-free blastocyst on the feeder layer, attached cell clumps was cultured with SC-1 until the endpoint of the experiment at passage 10. In this experiment, when the number of colonies was counted at passage 3, SC-1-treated group showed 3.4 fold more mESC colonies when compared with control group. However, after passage 4, there was no stimulating effect of SC-1 on the colony formation. In conclusion, SC-1 treatment can be used to promote mESC generation by increasing the number of early mESC colonies.

Antibacterial Activity of Powdered Spice against Escherichia coli and Staphylococcus aureus (향신료 분말의 Esdcherichia coli 와 Staphylococcus aureus 에 대한 항균작용)

  • 김미림;최경호;박찬성
    • Food Science and Preservation
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    • v.7 no.1
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    • pp.124-131
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    • 2000
  • Antibacterial activities of powdered spices(garlic , ginger, cinnamon and clove) against pathogenic Escherichia coli )157:H7 and Staphyloccus auresus were investigated. Spice powder was added in was exponetial phase of each bacterial culture . Growth inhibition was determined by the absorbance at 660nm and morphological changes of the cells were observed by transmission electron microscope (TEM). Ginger powder has the highest antibacterial activity, following cinnamon , clove and garlic has the least activity.Growth of Escherichia coli O157:H7 and Staphyloccus aureus were completely inhibited within 5 hours after addition of 1 % of garlic , 0.3% of ginger or cinnamon , 0.5% of clove powder on the exponential phase of the cells. Spice untreated cells of E. coli and S. aureus, the cytoplasm was entirely surrounded by rigid cell wall and cell walls formed a smooth layer well attached to the plasma membrane. In the cells of E. coli and S. aureus treated with spice powder, cell wall and plasma membrane were lysed and severely damaged. E.coli cells growth in the presence of spice powder showed plammolysis, the loss of electron dense material, the formation of extra cellular blebs and cytoplasm burst out from the cell. S .sureus cells grown in the presence of spice powder showed swell of cell wall, the loss of electron dense material , coagulation of cell cytoplasm and formation of extra cellular blebs. Severely damaged cells of S. aureus lost whole cytoplasm and left as ghost of the cell. Spice powder stimulated autolyssi and induced cell death.

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Suppression of MCF-7 Human Breast Cancer Cell Proliferation by Globefish Takifugu obscurus Homogenate (복어(Takifugu obscurus) 균질액에 의한 MCF-7 인간 유방암세포 성장 억제 효과)

  • Kim, Junghoon;Kim, Jungho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.53 no.6
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    • pp.878-885
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    • 2020
  • Previously, we reported that globefish Takifugu obscurus homogenate suppresses the growth of human colorectal cancer cells. To extend the applications of globefish homogenate, we investigated its cytotoxic effects on human breast cancer cells. To assess the effects of globefish homogenate on growth of MCF (Michigan Cancer Foundation)-7 human breast cancer cells, cell proliferation and colony formation assays were performed using the cell counting and Crystal Violet staining methods. The 50% inhibitory concentration (IC50) of globefish homogenate on MCF-7 cell proliferation was calculated from the sigmoidal dose-response curve. The colony formation assay demonstrated that MCF-7 cells treated with globefish homogenate formed up to 80% fewer colonies than control MCF-7 cells. Treatment with globefish homogenate markedly suppressed the growth of MCF-7 cells in a dose-dependent manner. The sensitivity of the cells to globefish homogenate was determined by calculating the IC50; in this case, the IC50 was 210 ㎍/mL. Furthermore, significant downregulation of Cyclin D1 expression, along with phospho-Akt and total Akt levels, was observed in MCF-7 cells treated with globefish homogenate. This study demonstrates that treatment with globefish homogenate inhibits the proliferation of MCF-7 human breast cancer cells by downregulating the expression of phosphor-Akt, total Akt, and Cyclin D1 proteins.

PKCβ Positively Regulates RANKL-Induced Osteoclastogenesis by Inactivating GSK-3β

  • Shin, Jihye;Jang, Hyunduk;Lin, Jingjing;Lee, Soo Young
    • Molecules and Cells
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    • v.37 no.10
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    • pp.747-752
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    • 2014
  • Protein kinase C (PKC) family members phosphorylate a wide variety of protein targets and are known to be involved in diverse cellular signaling pathways. However, the role of PKC in receptor activator of NF-${\kappa}B$ ligand (RANKL) signaling has remained elusive. We now demonstrate that $PKC{\beta}$ acts as a positive regulator which inactivates glycogen synthase kinase-$3{\beta}$ (GSK-$3{\beta}$) and promotes NFATc1 induction during RANKL-induced osteoclastogenesis. Among PKCs, $PKC{\beta}$ expression is increased by RANKL. Pharmacological inhibition of $PKC{\beta}$ decreased the formation of osteoclasts which was caused by the inhibition of NFATc1 induction. Importantly, the phosphorylation of GSK-$3{\beta}$ was decreased by $PKC{\beta}$ inhibition. Likewise, down-regulation of $PKC{\beta}$ by RNA interference suppressed osteoclast differentiation, NFATc1 induction, and GSK-$3{\beta}$ phosphorylation. The administration of PKC inhibitor to the RANKL-injected mouse calvaria efficiently protected RANKL-induced bone destruction. Thus, the $PKC{\beta}$ pathway, leading to GSK-$3{\beta}$ inactivation and NFATc1 induction, has a key role in the differentiation of osteoclasts. Our results also provide a further rationale for $PKC{\beta}$'s therapeutic targeting to treat inflammation-related bone diseases.

Increase of Cellular Alkaline Phosphatase Activity by Levamisole in Kidney Cells (신장 세포에서 Levamisole의 세포내 Alkaline Phosphatase 활성 증가)

  • Hwang, Joon-Il;Kim, Jong-Hwan;Kim, Joo-Il;Lee, Kyung-Tae;Kwon, Chang-Hoo
    • Journal of Pharmaceutical Investigation
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    • v.26 no.4
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    • pp.309-314
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    • 1996
  • The purpose of this study is to explain the relationship between the pharmacological mechanism of levamisole and the cellular activity of cellular alkaline phosphatase (ALPase) in kidney cells. The results of our investigation were as follows. 1. Cellular ALPase activity in Macacus rhesus monkey kidney cells (MA 104 cells) and primary cultured rabbit kidney proximal tubular cells treated with levamisole was increased about two or three times than control. However, 50% of ALPase activity in cultured medium was inhibited by levamisole itself. 2. The proliferation of MA 104 and cultured rabbit kidney proximal tubular cells was linearly decreased in paralleled with increase of levamisole concentration $(50\;and\;500\;{mu}M)$ with MTT test. 3. In the heat stability tests, the inhibition of ALPase activity with and without levamisole at $56^{\circ}C$ in MA 104 cells showed different $IC_{50}$ values. 4. HPLC analysis of levamisole metabolites produced by cultured MA 104 cells suggested that the formation of a metabolite, that may be associated with its increase of cellular ALPase activity. Based on these results, we assumed that the increase of cellular ALPase activity by levamisole was evoked by modification of the ALPase catalytic sites.

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