• 제목/요약/키워드: Cell Sorting

검색결과 136건 처리시간 0.032초

Efficient Calculation of Distance Fields Using Cell Subdivision (셀 분할을 이용한 거리장의 효율적 계산)

  • Yoo, Dong-Jin
    • Journal of the Korean Society for Precision Engineering
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    • 제25권3호
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    • pp.147-156
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    • 2008
  • A new approach based on cone prism intersection method combined with sorting algorithm is proposed for the fast and robust signed distance field computation. In the method, the space bounding the geometric model composed of triangular net is divided into multiple smaller cells. For the efficient calculation of distance fields, valid points among the triangular net which will generate minimum distances with current cell are selected by checking the intersection between current cell and cone prism generated at each point. The method is simple to implement and able to achieve an order of magnitude improvement in the computation time as compared to earlier approaches. Further the method is robust in handling the traditional sign problems. The validity of the suggested method was demonstrated by providing numerous examples including Boolean operation, shape deformation and morphing of complex geometric models.

MHC Multimer: A Molecular Toolbox for Immunologists

  • Chang, Jun
    • Molecules and Cells
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    • 제44권5호
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    • pp.328-334
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    • 2021
  • The advent of the major histocompatibility complex (MHC) multimer technology has led to a breakthrough in the quantification and analysis of antigen-specific T cells. In particular, this technology has dramatically advanced the measurement and analysis of CD8 T cells and is being applied more widely. In addition, the scope of application of MHC multimer technology is gradually expanding to other T cells such as CD4 T cells, natural killer T cells, and mucosal-associated invariant T cells. MHC multimer technology acts by complementing the T-cell receptor-MHC/peptide complex affinity, which is relatively low compared to antigen-antibody affinity, through a multivalent interaction. The application of MHC multimer technology has expanded to include various functions such as quantification and analysis of antigen-specific T cells, cell sorting, depletion, stimulation to replace antigen-presenting cells, and single-cell classification through DNA barcodes. This review aims to provide the latest knowledge of MHC multimer technology, which is constantly evolving, broaden understanding of this technology, and promote its widespread use.

Cytoprotective effect of rhamnetin on miconazole-induced H9c2 cell damage

  • Lee, Kang Pa;Kim, Jai-Eun;Park, Won-Hwan
    • Nutrition Research and Practice
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    • 제9권6호
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    • pp.586-591
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    • 2015
  • BACKGROUND/OBJECTIVES: Reactive oxygen species (ROS) formation is closely related to miconazole-induced heart dysfunction. Although rhamnetin has antioxidant effects, it remained unknown whether it can protect against miconazole-induced cardiomyocyte apoptosis. Thus, we investigated the effects of rhamnetin on miconazole-stimulated H9c2 cell apoptosis. MATERIALS/METHODS: Cell morphology was observed by inverted microscope and cell viability was determined using a WelCount$^{TM}$ cell proliferation assay kit. Miconazole-induced ROS production was evaluated by fluorescence-activated cell sorting with 6-carboxy-2',7'-dichlorofluoroscein diacetate ($H_2DCF$-DA) stain. Immunoblot analysis was used to determine apurinic/apyrimidinic endonuclease 1 (APE/Ref-1) and cleaved cysteine-aspartic protease (caspase) 3 expression. NADPH oxidase levels were measured using real-time polymerase chain reaction. RESULTS: Miconazole (3 and $10{\mu}M$) induced abnormal morphological changes and cell death in H9c2 cells. Rhamnetin enhanced the viability of miconazole ($3{\mu}M$)-treated cells in a dose-dependent manner. Rhamnetin (1 and $3{\mu}M$) treatment downregulated cleaved caspase 3 and upregulated APE/Ref-1 expression in miconazole-stimulated cells. Additionally, rhamnetin significantly reduced ROS generation. CONCLUSIONS: Our data suggest that rhamnetin may have cytoprotective effects in miconazole-stimulated H9c2 cardiomyocytes via ROS inhibition. This effect most likely occurs through the upregulation of APE/Ref-1 and attenuation of hydrogen peroxide levels.

Anti-Fibrotic Effects of DL-Glyceraldehyde in Hepatic Stellate Cells via Activation of ERK-JNK-Caspase-3 Signaling Axis

  • Md. Samsuzzaman;Sun Yeou Kim
    • Biomolecules & Therapeutics
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    • 제31권4호
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    • pp.425-433
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    • 2023
  • During liver injury, hepatic stellate cells can differentiate into myofibroblast-like structures, which are more susceptible to proliferation, migration, and extracellular matrix generation, leading to liver fibrosis. Anaerobic glycolysis is associated with activated stellate cells and glyceraldehyde (GA) is an inhibitor of glucose metabolism. Therefore, this study aimed to investigate the anti-fibrotic effects of GA in human stellate LX-2 cells. In this study, we used cell viability, morphological analysis, fluorescence-activated cell sorting (FACS), western blotting, and qRT-PCR techniques to elucidate the molecular mechanism underlying the anti-fibrotic effects of GA in LX-2 cells. The results showed that GA significantly reduced cell density and inhibited cell proliferation and lactate levels in LX-2 cells but not in Hep-G2 cells. We found that GA prominently increased the activation of caspase-3/9 for apoptosis induction, and a pan-caspase inhibitor, Z-VAD-fmk, attenuated the cell death and apoptosis effects of GA, suggesting caspase-dependent cell death. Moreover, GA strongly elevated reactive oxygen species (ROS) production and notably increased the phosphorylation of ERK and JNK. Interestingly, it dramatically reduced α-SMA and collagen type I protein and mRNA expression levels in LX-2 cells. Thus, inhibition of ERK and JNK activation significantly rescued GA-induced cell growth suppression and apoptosis in LX-2 cells. Collectively, the current study provides important information demonstrating the anti-fibrotic effects of GA, a glycolytic metabolite, and demonstrates the therapeutic potency of metabolic factors in liver fibrosis.

Ectopic Expression of Mitochondria Endonuclease Pnu1p from Schizosaccharomyces pombe Induces Cell Death of the Yeast

  • Oda, Kaoru;Kawasaki, Nami;Fukuyama, Masashi;Ikeda, Shogo
    • BMB Reports
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    • 제40권6호
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    • pp.1095-1099
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    • 2007
  • Endonuclease G (EndoG) is a mitochondrial non-specific nuclease that is highly conserved among the eukaryotes. Although the precise role of EndoG in mitochondria is not yet known, the enzyme is released from the mitochondria and digests nuclear DNA during apoptosis in mammalian cells. Schizosaccharomyces pombe has an EndoG homolog Pnu1p (previously named SpNuc1) that is produced as a precursor protein with a mitochondrial targeting sequence. During the sorting into mitochondria the signal sequence is cleaved to yield the functionally active endonuclease. From the analogy to EndoG, active extramitochondrial Pnu1p may trigger cell killing by degrading nuclear DNA. Here, we tested this possibility by expressing a truncated Pnu1p lacking the signal sequence in the extramitochondrial region of pnu1-deleted cells. The truncated Pnu1p was localized in the cytosol and nuclei of yeast cells. And ectopic expression of active Pnu1p led to cell death with fragmentation of nuclear DNA. This suggests that the Pnu1p is possibly involved in a certain type of yeast cell death via DNA fragmentation. Although expression of human Bak in S. pombe was lethal, Pnu1p nuclease is not necessary for hBak-induced cell death.

Immunomodulatory Effects of Hominis Placenta Extract Injection into an Acupuncture Point on the Experimental Subcutaneous Tumor Model of Mice

  • Lee, Soo-Jin
    • Journal of Physiology & Pathology in Korean Medicine
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    • 제20권5호
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    • pp.1285-1289
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    • 2006
  • Hominis placenta (HP) has been used as an agent for promoting physiological function in traditional asian medicine. The present study was peformed to investigate whether HP acupuncture treatment in an experimental tumor mice model inhibit tumor growth through immunomodulatory effects. Mice were inoculated subcutaneously with colon26-L5 cells on the back. Three days after tumor inoculation, HP herbal acupuncture treatment was conducted on BL18 acupoint every other day for three weeks. HP Herbal acupuncture treatment significantly suppressed the primary tumor growth and prolonged survival rate. To evaluate immunomodulatory effect of HP acupuncture, splenocytes proliferation assay, fluorescence-activated cell sorting (FACS) and ELISA for IFN- ${\gamma}$, and IL-4 cytokine level. HP herbal acupuncture enhanced the mitogenic activity of Balb/c whole splenocytes induced by various mitogenic stimuli and increased immune cell population such as T cell, B cell, Th cell, Tc cell and Macrophages. HP herbal acupuncture caused a marked increase of production of Th1 cytokine (IFN- ${\gamma}$ ,) and decrease of production of Th2 cytokine (IL-4). These results indicated that HP herbal acupuncture suppresses tumor growth through a mechanism leading to a Th1 dominant immune state.

Development of Simple Density Measurement System for Watermelons (수박 밀도의 간편 계측시스템 개발)

  • 최규홍;이강진;최동수;김기영;손재룡
    • Journal of Biosystems Engineering
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    • 제29권2호
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    • pp.167-174
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    • 2004
  • Density is a physical property which contains information relating to the internal quality of fruits and vegetables, and can be used as an index for nondestructive quality evaluation. Density sorting has been employed by farmers for some agricultural products since ancient times. In this study, an automatic density measuring system based on the platform scale or water displacement method was developed for density sorting of watermelon. It consisted of water tan, load cell, net tray, electric motor, limit switch, control system and its program. The resolution of density was 0.001 g/㎤. In order to calibrate and evaluate the accuracy, the density was measured using a balloon kept in cold water. It showed 1.002 g/㎤ which almost correspond to real density of water. Test results with 6 watermelons and 3 replications showed that the standard deviations of the dens were 0.001∼0.004 g/㎤. The relationship between density and internal quality of watermelon was investigated using the system. The densities of hollow watermelons were less than 0.950 g/㎤, it was apparent that the density of the watermelon was related to the degree of hollowness. But the soluble solid contents and internal defects could not be estimated from the density.

Anti-cancer and anti-inflammatory effects of convergence of ginsenoside Rh2, compound K isolated from amplified red ginseng (증폭시킨 홍삼으로부터 분리한 ginsenoside Rh2, compound K의 융복합적 항암 및 항염효과)

  • Kim, Young-Ho;Kim, Jong-Du
    • Journal of Digital Convergence
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    • 제15권11호
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    • pp.285-295
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    • 2017
  • This study aims to provide basic data on useful functional ingredients in red ginseng by studying the anti-inflammatory and anti-cancer effects of convergence of ginsenoside Rh2(Rh2) and compound K(CK) isolated from amplified red ginseng. Therefore we examined cytotoxicity in Hep3B, activity of IL-6 induced STAT3 luciferase and survival concentration of cells in B16F10 and HaCa T. According to the experimental results, when the Rh2 and CK mixture were 10 ug/ml, there was no cytotoxicity in Hep3B cells and the anti-inflammatory effect of IL-6 reduction ratio was 102%. In addition, Rh2 and CK mixture were observed to be toxic in melanoma cell line B16F10 and HaCa T (human keratinocyte) at 50 uM. FACS(fluorescence activated cell sorting) analysis showed that annexin V was not expressed and melanoma cells and keratinocyte were desorbed and killed. It can be assumed that the mechanism of killing through this phenomenon is due to the cell death of anoikis-type, and it is necessary to study the changes of cell adhesion proteins in the future in order to clarify the cell death signal system.

Modulation of Pituitary Somatostatin Receptor Subtype (sst1-5) mRNA Levels by Growth Hormone (GH)-Releasing Hormone in Purified Somatotropes

  • Park, Seung-Joon;Park, Hee-Soon;Lee, Mi-Na;Sohn, Sook-Jin;Kim, Eun-Hee;Jung, Jee-Chang;Frohman, Lawrence A.;Kineman, Rhonda D.
    • The Korean Journal of Physiology and Pharmacology
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    • 제7권2호
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    • pp.79-84
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    • 2003
  • We have previously reported that expression of the somatostatin receptor subtypes, sst1-5, is differentially regulated by growth hormone (GH)-releasing hormone (GHRH) and forskolin (FSK), in vitro. GHRH binds to membrane receptors selectively located on pituitary somatotropes, activates adenylyl cyclase (AC) and increases sst1 and sst2 and decreases sst5 mRNA levels, without significantly altering the expression of sst3 and sst4. In contrast FSK directly activates AC in all pituitary cell types and increases sst1 and sst2 mRNA levels and decreases sst3, sst4 and sst5 expression. Two explanations could account for these differential effects: 1) GHRH inhibits sst3 and sst4 expression in somatotropes, but this inhibitory effect is masked by expression of these receptors in unresponsive pituitary cell types, and 2) FSK inhibits sst3 and sst4 expression levels in pituitary cell types other than somatotropes. To differentiate between these two possibilities, somatotropes were sequentially labeled with monkey anti-rat GH antiserum, biotinylated goat anti-human IgG, and streptavidin-PE and subsequently purified by fluorescent-activated cell sorting (FACS). The resultant cell population consisted of 95% somatotropes, as determined by GH immunohistochemistry using a primary GH antiserum different from that used for FACS sorting. Purified somatotropes were cultured for 3 days and treated for 4 h with vehicle, GHRH (10 nM) or FSK ($10{\mu}M$). Total RNA was isolated by column extraction and specific receptor mRNA levels were determined by semi-quantitative multiplex RT-PCR. Under basal conditions, the relative expression levels of the various somatostatin receptor subtypes were sst2>sst5>sst3=sst1> sst4. GHRH treatment increased sst1 and sst2 mRNA levels and decreased sst3, sst4 and sst5 mRNA levels in purified somatotropes, comparable to the effects of FSK on purified somatotropes and mixed pituitary cell cultures. Taken together, these results demonstrate that GHRH acutely modulates the expression of all somatostatin receptor subtypes within GH-producing cells and its actions are likely mediated by activation of AC.

Over Expression of BCL2 and Low Expression of Caspase 8 Related to TRAIL Resistance in Brain Cancer Stem Cells

  • Qi, Ling;Ren, Kuang;Fang, Fang;Zhao, Dong-Hai;Yang, Ning-Jiang;Li, Yan
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권12호
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    • pp.4849-4852
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    • 2015
  • Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been investigated as an effective agent to treat various cancers. Cancer stem cells are resistant to TRAIL treatment, but the mechanism of TRAIL resistance remains unknown. In this study, brain cancer stem cells were isolated by CD133 magnetic sorting, and the number of CD133 positive cells detected by flow cytometry. The self-renewing capacity of brain cancer stem cells was examined by a neurosphere formation assay, and the percentage of cell death after TRAIL treatment was examined by an MTS assay. Expression of DR5, FADD, caspase 8 and BCL2 proteins was detected by western blot. The amount of CD133 positive cells was enriched to 71% after CD133 magnetic sorting. Brain cancer stem cell neurosphere formation was significantly increased after TRAIL treatment. TRAIL treatment also reduced the amount of viable cells and this decrease was inhibited by a caspase 8 inhibitor or by the pan-caspase inhibitor z-VAD (P<0.05). Brain cancer stem cells expressed lower levels caspase 8 protein and higher levels of BCL2 protein when compared with CD133 negative cells (P<0.05). Our data suggest that TRAIL resistance is related to overexpression of BCL2 and low expression of caspase 8 which limit activation of caspase 8 in brain cancer stem cells.