• 제목/요약/키워드: Cell biology

검색결과 7,158건 처리시간 0.03초

Comparison of the Virulence-Associated Phenotypes of Five Species of Acinetobacter baumannii Complex

  • Na, In Young;Chung, Eun Seon;Jung, Chang-Yun;Kim, Dae Hun;Shin, Juyoun;Kang, KyeongJin;Kim, Seong-Tae;Ko, Kwan Soo
    • Journal of Microbiology and Biotechnology
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    • 제26권1호
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    • pp.171-179
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    • 2016
  • In this study, we compared the virulence-associated factors of Acinetobacter baumannii complex species. Sixty-three isolates of five A. baumannii complex species, including 19 A. baumannii, 15 A. nosocomialis, 13 A. seifertii, 13 A. pittii, and 3 A. calcoaceticus isolates, were included in this study. For all isolates, biofilm formation, A549 cell adherence, resistance to normal human serum, and motility were evaluated. A. baumannii complex isolates showed diversity in biofilm formation, A549 cell adherence, and serum resistance, and no strong positive relationships among these virulence characteristics. However, A. seifertii showed relatively consistent virulence-associated phenotypes. In addition, A. baumannii clone ST110 exhibited consistently high virulence-associated phenotypes. Motility was observed in seven isolates, and all four A. baumannii ST110 isolates showed twitching motility. Although some inconsistencies in virulence-associated phenotypes were seen, high virulence characteristics were observed in A. seifertii, which has been mainly reported in Korea and shows high rates of colistin resistance.

Purification and Characterization of Hrp1, a Homolog of Mouse CHD1 from the Fission Yeast Schizosaccharomyces pombe

  • Yong Hwan Jin;Eung Jae Yoo;Yeun Kyu Jang;Seung Hae Kim;Chee-Gun Lee;Rho Hyun Seong;Seung Hwan Hong;Sang Dai Park
    • Animal cells and systems
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    • 제2권4호
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    • pp.539-543
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    • 1998
  • Hrp1, of Schizosaccharomyces pombe, is a new member of the SW12/SNF2 protein family that contains a chromodomain and a DNA binding domain as well as ATPase/7 helicase domains. This configuration suggests that Hrp1 could be a homolog of mouse CHD1, which is thought to function in altering the chromatin structure to facilitate gene expression. To understand the enzymatic nature of Hrp1 we purified the 6-Histidine-tagged Hrp1 protein (6$\times$His-Hrp1) to homogeneity from a S. pombe Hrp1-overexpressing strain and hen examined its biochemical properties. We demonstrate that the purified 6$\times$His-Hrp1 protein exhibited a DNA-binding activity with a moderate preference to the (A+T)-rich tract in double-stranded NA via a minor groove interaction. However, we failed to detect any intrinsic DNA helicase activity from the purified Hrp1 like other SW12/SNF2 proteins. These observations suggest that the DNA binding activities of Hrp1 may be involved in the remodeling of the chromatin structure with DNA-dependent ATPase. We propose that Hrp1 may function in heterochromatins as other proteins with a chromo- or ATPase/helicase domain and play an important role in the determination of chromatin architecture.

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Immortalization of Rabbit Corneal Fibroblasts by Overexpression of Simian Virus 40 Large T antigen

  • Cho, Seung-Ju;Park, Yuk-Pheel;Lim, Heon-Man;Kim, Jae-Chan;Yang, Eun-Kyung;Park, Jung-Keug;Yoon, Do-Young;Lee, Hee-Gu
    • 대한의생명과학회지
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    • 제10권2호
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    • pp.85-92
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    • 2004
  • Immortalization of primary corneal cells has influence on pharmacy, medical and biological fields. Especially, investigation of immortalization mechanism using viral oncoproteins is useful for medical treatments, and these cell lines will be useful materials for toxic test of medical supplies and cell biological experiments. Rabbit corneal fibroblasts in culture undergo a finite number of divisions before they reach a terminally non-proliferating state known as replicative senescence. Therefore, we attempted to induce immortalization of rabbit corneal fibroblasts with SV 40 large T antigen. As a result of experiment, expression of SV 40 large T antigen was confirmed, and expression of proteins related to cell cycle repressor was decreased in the transfection group compared with non-transfection group. According to the results of cell cycle phase distribution test, SV 40 large T antigen-transfected cells had obtained higher proliferation rate than primary cells. It was confirmed that during induction of immortalization, SV 40 large T antigen was not able to increase telomerase activity. In conclusion, we made a rabbit corneal fibroblast cell line with SV40 large T antigen. This cell line will be useful for further studies of mammalian fibroblast biology, particularly with regard to angiogenesis and malignant transformation. In addition, this cell line offers opportunity for testing potential therapeutics and can be used for toxicity tests of materials or cosmetics. In the future, our cell line can potentially be utilized in a wide range of biology related fields.

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Establishment and Characterization of Permanent Cell Lines from Oryzias dancena Embryos

  • Lee, Dongwook;Kim, Min Sung;Nam, Yoon Kwon;Kim, Dong Soo;Gong, Seung Pyo
    • Fisheries and Aquatic Sciences
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    • 제16권3호
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    • pp.177-185
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    • 2013
  • The development of species-specific fish cell lines has become a valuable tool for biological research. In recent years, marine medaka Oryzias dancena has been recognized as a good experimental model fish but there are no reports of establishment of cell lines from this fish. In this study, two cell lines from O. dancena blastula embryos were established from 41 total trials (4.9%). The two cell lines displayed typical in vitro morphology and have been cultured for >121 passages, which corresponds to 293 days. The doubling times of the cell lines were 29.84 and 28.59 h, respectively, and both possessed the potential to expand in a clonal manner, albeit with significant differences between the two cell lines. The absence of any of the four main medium supplements; i.e., fish serum, fetal bovine serum, basic fibroblast growth factor, and medaka embryo extract, significantly inhibited growth. The proportion of cells possessing normal chromosome number was 45% and 46.7% of the cell lines, respectively. Taken together, two cell lines that proliferate continuously were established from marine medaka and these cell lines may provide a basic tool for characterizing the unique features of this fish species.

P42 Ebp1 functions as a tumor suppressor in non-small cell lung cancer

  • Ko, Hyo Rim;Nguyen, Truong L.X.;Kim, Chung Kwon;Park, Youngbin;Lee, Kyung-Hoon;Ahn, Jee-Yin
    • BMB Reports
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    • 제48권3호
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    • pp.159-165
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    • 2015
  • Although the short isoform of ErbB3-binding protein 1 (Ebp1), p42 has been considered to be a potent tumor suppressor in a number of human cancers, whether p42 suppresses tumorigenesis of lung cancer cells has never been clarified. In the current study we investigated the tumor suppressor role of p42 in non-small cell lung cancer cells. Our data suggest that the expression level of p42 is inversely correlated with the cancerous properties of NSCLC cells and that ectopic expression of p42 is sufficient to inhibit cell proliferation, anchorage-independent growth, and invasion as well as tumor growth in vivo. Interestingly, p42 suppresses Akt activation and overexpression of a constitutively active form of Akt restores the tumorigenic activity of A549 cells that is ablated by exogenous p42 expression. Thus, we propose that p42 Ebp1 functions as a potent tumor suppressor of NSCLC through interruption of Akt signaling.

Protective effect of Oxya chinensis sinuosa methanol extract on UVB-induced damage in human retinal pigment epithelial cells

  • Hyun Jung Lim;Sohyun Park;Joon Ha Lee;In-Woo Kim;HaeYong Kweon;Minchul Seo
    • International Journal of Industrial Entomology and Biomaterials
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    • 제47권2호
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    • pp.90-98
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    • 2023
  • The human eye, constantly exposed to solar radiation, can be damaged by UV radiation. In particular, ultraviolet B (UVB)-induced damage plays an important role in retinal degeneration and cell aging. In this study, we investigated the protective effects of the methanol extract of Oxya chinensis sinuosa (OCM), an edible insect known for its high protein content (64.2%), and various pharmacological effects, on human retinal pigment epithelial cells. ARPE-19 cells were treated with OCM and subsequently UVB irradiated. Our results showed that OCM effectively attenuates UVB-induced cell damage by reducing MAPK phosphorylation (JNK and p38 MAPK). Additionally, OCM increased the phosphorylation of Akt, and cell cycle regulators, including p21 and p27, in a dose-dependent manner. Moreover, OCM treatment increased ARPE-19 cell proliferation by activating the S6K1/S6 pathway. This study suggests that OCM prevents UVB-induced retinal cell damage by increasing cell proliferation via ROS reduction, suggesting its potential as a functional therapeutic superfood against retinal cell damage.

Long-Term Priming by Three Small Molecules Is a Promising Strategy for Enhancing Late Endothelial Progenitor Cell Bioactivities

  • Kim, Yeon-Ju;Ji, Seung Taek;Kim, Da Yeon;Jung, Seok Yun;Kang, Songhwa;Park, Ji Hye;Jang, Woong Bi;Yun, Jisoo;Ha, Jongseong;Lee, Dong Hyung;Kwon, Sang-Mo
    • Molecules and Cells
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    • 제41권6호
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    • pp.582-590
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    • 2018
  • Endothelial progenitor cells (EPCs) and outgrowth endothelial cells (OECs) play a pivotal role in vascular regeneration in ischemic tissues; however, their therapeutic application in clinical settings is limited due to the low quality and quantity of patient-derived circulating EPCs. To solve this problem, we evaluated whether three priming small molecules (tauroursodeoxycholic acid, fucoidan, and oleuropein) could enhance the angiogenic potential of EPCs. Such enhancement would promote the cellular bioactivities and help to develop functionally improved EPC therapeutics for ischemic diseases by accelerating the priming effect of the defined physiological molecules. We found that preconditioning of each of the three small molecules significantly induced the differentiation potential of $CD34^+$ stem cells into EPC lineage cells. Notably, long-term priming of OECs with the three chemical cocktail (OEC-3C) increased the proliferation potential of EPCs via ERK activation. The migration, invasion, and tube-forming capacities were also significantly enhanced in OEC-3Cs compared with unprimed OECs. Further, the cell survival ratio was dramatically increased in OEC-3Cs against $H_2O_2$-induced oxidative stress via the augmented expression of Bcl-2, a pro-survival protein. In conclusion, we identified three small molecules for enhancing the bioactivities of ex vivo-expanded OECs for vascular repair. Long-term 3C priming might be a promising methodology for EPC-based therapy against ischemic diseases.

Dronedarone hydrochloride enhances the bioactivity of endothelial progenitor cells via regulation of the AKT signaling pathway

  • Zhang, Jian;Le, Thi Hong Van;Rethineswaran, Vinoth Kumar;Kim, Yeon-Ju;Jang, Woong Bi;Ji, Seung Taek;Ly, Thanh Truong Giang;Ha, Jong Seong;Yun, Jisoo;Cheong, Jae Hun;Jung, Jinsup;Kwon, Sang-Mo
    • The Korean Journal of Physiology and Pharmacology
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    • 제25권5호
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    • pp.459-466
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    • 2021
  • Cardiovascular disease (CVD) and its complications are the leading cause of morbidity and mortality in the world. Because of the side effects and incomplete recovery from current therapy, stem cell therapy emerges as a potential therapy for CVD treatment, and endothelial progenitor cell (EPC) is one of the key stem cells used for therapeutic applications. The effect of this therapy required the expansion of EPC function. To enhance the EPC activation, proliferation, and angiogenesis using dronedarone hydrochloride (DH) is the purpose of this study. DH received approval for atrial fibrillation treatment and its cardiovascular protective effects were already reported. In this study, DH significantly increased EPC proliferation, tube formation, migration, and maintained EPCs surface marker expression. In addition, DH treatment up-regulated the phosphorylation of AKT and reduced the reactive oxygen species production. In summary, the cell priming by DH considerably improved the functional activity of EPCs, and the use of which might be a novel strategy for CVD treatment.