• Bulletin of the Korean Chemical Society
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• v.35 no.10
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• pp.2985-2989
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• 2014

Autophagy is a self-digestion process in which intracellular structures are degraded in response to stress. Notably, prolonged autophagy leads to cell death. In this study, we investigated whether CX-4945, an orally available protein kinase 2 (CK2) inhibitor, induces autophagic cell death in human cervical cancer-derived HeLa cells and in human prostate cancer-derived LNCaP cells. CX-4945 treatment of both cell lines resulted in the formation of autophagosomes, in the conversion of microtubule-associated protein 1 light chain 3 (LC3), and in down-regulation of the Akt-mammalian target of rapamycin (mTOR)-p70 ribosomal protein S6 kinase (S6K) signaling cascade. Thus, pharmacologic inhibition of CK2 by CX-4945 induced autophagic cell death in human cancer cells by down-regulating Akt-mTOR-S6K. These results suggest that autophagy-inducing agents have potential as anti-cancer drugs.

• The Journal of Korean Physical Therapy
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• v.17 no.3
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• pp.391-401
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• 2005

The purpose of this study was to investigate the effect of electrical stimulation(EST) on MAP2(Microtubule Associated Protein 2) expression in cerebral cortex following sciatic nerve crush injury in rats. Twelve Sprague-Dawley adult female rats, six for control and six for experimental, were anesthetized and their sciatic nerves were crushed. The electrical stimulation (EST) was applicated with 3 Hz for 10 minuties in a day for muscles innervated sciatic nerve. The MAP2 expression in cerebral cortex was identified from immunohistochemistry against MAP2. The result of this study were as follow: 1) In control group, MAP2 immunoreactive neurons were observed but there no significant increase for 3 days. 2) MAP2 immunoreactive neurons were increased markably in experimental group than control group. 3) MAP2 immunoreactive neurons were increased markably after applicating with EST in sciatic nerve crush injury induced group from 2nd day. This study showed that the application of EST for muscles after sciatic nerve crushed injury made MAP2 immunoreactive neurons in the cerebral cortex increased. Therefore, the electrical stimulation on the peripheral site, denervated muscle, may facilitate MAP2 expression in the cerebral cortex.

• Molecules and Cells
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• v.43 no.8
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• pp.705-717
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• 2020

While the growth factors like insulin initiate a signaling cascade to induce conformational changes in the mechanistic target of rapamycin complex 1 (mTORC1), amino acids cause the complex to localize to the site of activation, the lysosome. The precise mechanism of how mTORC1 moves in and out of the lysosome is yet to be elucidated in detail. Here we report that microtubules and the motor protein KIF11 are required for the proper dissociation of mTORC1 from the lysosome upon amino acid scarcity. When microtubules are disrupted or KIF11 is knocked down, we observe that mTORC1 localizes to the lysosome even in the amino acid-starved situation where it should be dispersed in the cytosol, causing an elevated mTORC1 activity. Moreover, in the mechanistic perspective, we discover that mTORC1 interacts with KIF11 on the motor domain of KIF11, enabling the complex to move out of the lysosome along microtubules. Our results suggest not only a novel way of the regulation regarding amino acid availability for mTORC1, but also a new role of KIF11 and microtubules in mTOR signaling.

• Fisheries and Aquatic Sciences
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• v.9 no.1
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• pp.1-6
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• 2006

Mature spermatozoa of dark chub Zacco temmincki (Temminck and Schlegel), were examined under a scanning electron microscope (SEM) and a transmission electron microscope (TEM). The spermatozoa have a spherical, homogeneously electron-dense nucleus with an axial nuclear fossa containing two laterally oriented centrioles. The centrioles, which are arranged at about a $120^{\circ}$ angle to each other, have the 9+2 microtubule structure typical of flagella. The mature spermatozoon is of the primitive anacrosomal aquasperm type. The nuclear envelope is strongly undulated and contains nuclear vacuoles of different sizes and positions. The midpiece contains six or more mitochondria and encircles the basal body of the flagellum with an axoneme covered by the plasma membrane. Cytoplasmic vesicles lie between the axonemal doublets and the plasma membrane, and encircle the anterior part of the tail. The plasma membrane of the flagellum extends laterally and forms a pair of side fins. The species showed minor differences in number and structure of mitochondria, the angle between centrioles, and total length and occurrence of the fins. These characters, especially the side fins, appear to be apomorphic and useful for determining phylogenetic relationships at the genus or family level.

• Korean Journal of Microbiology
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• v.17 no.1
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• pp.1-15
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• 1979

Mycoplasma pneumoniae strain CL-s attached to broth-covered surfaces was examined sequentially during growth from single cells for morphologic and ultrastructural changes using several different electron microscopic techniques. Changes in morphology revealed both round and spindle shapes and observation of cell transitions suggested some type of morphological cycle. The round to-ovoid cells observed in the early stages of growth appeared to be viable, and morphologically and ultrastructurally different from the spherical fors which were produced during the latter stage of growth. The spindle segments were detected appeared to be structurally the same as the terminal cored structure seen in thin sections and may be a growing point or an attachment site of the cell. A tubular structure was observed in the core of the terminal structure and a microtubule-like element appeared to bridge between some spindle segments. A matrix sunstance was observed around single cells as well in the intercellular space of the colonies prepared by critical point metrical triple-layered cytoplasmic mermbranes, surfaces, of which appeared to be structurally different each other, were observed in young cells, whereas symmetrical and thicker membranes were seen in older cells. Small bodies were found in 4d or older cultures and did not appear to contain any internal structures or an easily detectable unit membrane.

• Journal of Periodontal and Implant Science
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• v.35 no.4
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• pp.1081-1095
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• 2005

본 연구는 치주질환 주요 병인균주 중의 하나인 Porphyromonas gingivalis의 세균내독소가 마우스 대식 세포주인 RAW264.7 세포에서의 nitric oxide의 생성과 iNOS의 발현에 미치는 영향을 분석하고 그 기전을 규명하기 위해 수행되었다. Butanol추출법과 phenol-water법에 의해 P. gingivalis 381로부터 세균내독소를 추출하였으며, NO의 생성은 배양 상층액 내의 nitrite 농도를 측정하여 결정하였다. 또한, iNOS의 western blot 분석과 reverse transcription (RT)-PCR 산물의 분석을 수행하였다. P. gingivalis의 세균내독소는 부가적인 자극이 없는 상태에서도 iNOS의 발현과 NO 생성을 유발하였으며, NF- ${\kappa}B$, microtubule polymerization, protein tyrosine kinase, 그리고 protein kinase C 등이 P. gingivalis 세균내독소에 의한 NO 생성에 간여하는 것으로 여겨진다. 또한, P. gingivalis 세균내독소에 의한 NO 생성에는 L-arginine이 요구되었다. P. gingivalis 세균내독소에 의한 NO 생성은 염증성 치주질환의 발병과 진행에 있어 중요한 역할을 하는 것으로 여겨진다.

• Korean Journal of Veterinary Research
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• v.60 no.2
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• pp.79-83
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• 2020

Fenbendazole (FBZ) is a benzimidazole anthelmintic that has been widely used in treatments for gastrointestinal parasites including pinworms and roundworms in animals. Recently, some studies demonstrated that FBZ has anti-cancer effects related to disruption of microtubule polymerization. In this study, we investigated whether FBZ has anti-cancer activity in HL-60 cells, a human leukemia cell line, and assessed its relationship with the production of reactive oxygen species (ROS). FBZ treatment at 0.25-1 μM significantly decreased the metabolic activity of HL-60 cells. The mitochondrial membrane potential of FBZ-treated HL-60 cells decreased in a concentration-dependent manner. Apoptosis analysis using annexin V-FITC/propidium iodide staining demonstrated that 1 μM FBZ increased the percentages of cells in apoptosis and necrosis. In addition, Hoechst 33342 staining showed the presence of broken nuclei in HL-60 cells treated with 0.5 and 1 μM FBZ. To investigate the anti-cancer mechanism of FBZ, HL-60 cells were treated with FBZ in the absence or presence of N-acetyl cysteine (NAC), an inhibitor of ROS production. NAC significantly recovered the decreased metabolic activity of HL-60 induced by 0.5 and 1 μM FBZ treatments. This study provides evidence that FBZ has anti-cancer activity in HL-60 cells provided, in part, via ROS production.

• Journal of Environmental Health Sciences
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• v.26 no.4
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• pp.88-96
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• 2000

The aim of the current study was to evaluate the transport system in EMT-6 cell for the uptake of the methylmercury(MeHg). Several inhibitors ere used to test used to test which potential transport system might be involoved in MeHg uptake. Probenecid was used to test the organic transport system, valinomycin for testing the effect of the membrane potential, cytochalasin B for testing the facilitated diffusive D-glucose transport system and colchicine for testing the microtubule system. Ouabain for evaluating active transport system, 4',4-diisothiocyano-2',2-stilbenedisulfonic acid(DIDS) the Cl- ion transport system and verapamil for the $Ca^{2+}$ transprot system. Significantly, MeHg decreased the synthesis of nitric oxcide(NO) and intracellular ATP in ENT-6 cells. In the condition of ouabain containing with MeHg decreased the production of NO and intracelluar ATP. In the treatment of inhibitors, ouabain showed protective effect against cytotoxicity of MeHg but ather inhibitors not showed protective effects. The protective effects of ouabain against the cytotoxicity of MeHg deoended on the concentration of added ouabain to the culture medium for MET-6 cells. These result showed that the uptake of MeHg might be involved in the active transport system. Active transports system seems to share similarities with the transport systems for the uptake of MeHg when using MeHg and MeHg-glutathione complex.x.

• Journal of Embryo Transfer
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• v.32 no.3
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• pp.105-109
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• 2017

Autophagy is an intracellular degradation and recycling system. Oocyte maturation is dynamic process, in which various proteins should be synthesized and degraded. In our previous study, we reported the loci of autophagosome and dynamics of autophagic activity in porcine oocytes during in vitro maturation. In this study, we verified loci of autophagosome in porcine follicular cumulus-oocyte complex by detection of microtubule-associated protein 1A/1B-light chain 3 (LC3) which is the reliable marker of autophagosome. Porcine ovary including various sizes of follicles was fixed within 1 hour after collection from slaughterhouse. After fixation, immunohistochemistry was conducted on sliced ovary tissue containing various sizes of follicles by using LC3 antibody. As a result, LC3 signal was clearly detected in both cumulus and oocytes of various sizes of follicles. We also found ring shaped signal which represent autophagosome near oocyte membrane. Most of the signals in oocytes were localized nearby cellular membrane while evenly dispersed in cumulus cells. Therefore, this result suggests that autophagy occurs in porcine COCs (cumulus-oocyte complexes) at follicular stage.

• Journal of Microbiology and Biotechnology
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• v.11 no.5
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• pp.876-879
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• 2001

${\gamma}$ -Tubulin is an essential component involved in microtubule nucleation. The present work examined whether the fast proliferation of cancer cells can be retarded by the depletion of ${\gamma}$ -tubulin expression. Two different gastric cancer cell lines and one control cell line were treated with antisence oligonucleotides complementary to the messenger RNA of ${\gamma}$ -tubulin. The$[^3H]$ -thymidine incorporation in the two gastric cancer cell lines, SNU-1 and SNU-216, was dramatically reducd by treatment with the ${\gamma}$ -tubulin antisense oligonucleotides in a dosage-dependent manner. In contrast, the control cell line, NIH/3T3, showed no significant effect from the antisense oligonucleotides even at a high concentration. The ablation of ${\gamma}$ -tubulin expression in the tumor cells resulted in an altered DNA synthesis during mitosis and it decreased the cell progression. Accordingly, the use of antisense oligonucleotides may be an effective way of inhibiting the proliferation of human gastric cancers.