• Korean Journal of Microbiology
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• v.45 no.3
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• pp.246-250
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• 2009

Retroviruses enter host cells by membrane fusion between the viral Env proteins on the virus membrane and a virus receptor on the cellular membrane. The envelope protein of the ecotropic Moloney murine leukemia virus is synthesized as a gp85 precursor and is proteolytically cleaved into an extracellular surface unit (SU) and the transmembrane protein (TM). The cytoplasmic tail (16 amino acid; R peptide) of the TM protein is further cleaved by the viral protease during virion maturation. Unlike the wild type Env protrin bearing the R peptide, R peptide-truncated Envelope induces syncytia in susceptible cells. To understand the mechanism of R peptidetruncated Env in syncytium formation, R peptide-truncated Env expressing full-length molecular clone containing EGFP in PRR (proline rich region) of Env was constructed. This molecular clone induced syncytia in transfected NIH3T3 cells, fluorescence was detected in the cytoplasm and at the plasma membrane, while the nuclei did not stain and appeared black by fluorescence microscopy. Interestingly, virions with truncated envelope produced from transfected NIH3T3 cells induced syncytia in NIH3T3 cells, but fluorescence was not detected in the same infected cells. It is believed that cell-free viruses direct the fusion of neighboring cells without infection. Our data suggests that use of EGFP-tagged envelope for monitoring syncytium is a sensitive and convenient method. We also found that virion incorporated the R peptide-truncated Env is able to induce the formation of syncytia by fusion from without.

• Journal of Life Science
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• v.21 no.12
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• pp.1752-1760
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• 2011

In this study, the effect of the Opuntiahumifusa extracts on proliferation, alkaline phosphatase (ALP) activity, collagen synthesis and ROS level of a cell was investigated using an osteoblast. Opuntiahumifusawas separated intoOpuntiahumifusapeel (OH-P), seed (OH-Se) and stem (OH-St).These were subjected to extraction by using hot water and ethanol. The proliferation of the MC3T3-E1 osteoblastic cells that were treated with OH-Se water extract were increased by approximately 120%. Regarding the effects of OH-Se on ALP activity, the $50{\mu}g/ml$ ethanol extract group showed the highest activity. The synthesis of collagen increased significantly in response to treatment with OH-Se water extract. The ROS scavenging effects of Opuntiahumifusawere investigated for involvement of oxidativedamage, cell culture and staining. Also, when OH-Se water extract $100{\mu}g/ml$ was added, the ROS level decreased by 54%. These results indicate that Opuntiahumifusa extracts have an anabolic effect on bone through the promotion of osteoblastic differentiation, suggesting that it could be used for the treatment of common metabolic bone diseases.

• Journal of Korean Ophthalmic Optics Society
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• v.6 no.2
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• pp.149-153
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• 2001

This study was performed to examine the cytotoxicity and antimicrobial activity of synthetic or natural preservative. Fibroblast cells L929 were used for cytotoxicity test and Pseudomonas aeruginosa ATCC27853, Staphylococcus aureus ATCC25923, Escherichia coli ATCC25922, Trichoderma reesei ATCC6967 were used for antibacterial and antifungal activities. Benzalkonium chloride(BAC) as a synthetic preservative and chitosan as a natural preservative were used for this study. Minimum inhibitory concentration(MIC) of BAC was 0.1~0.01% for P. aeruginosa and 0.001~0.0001% for S. aureus and 0.1~0.01% for T. reesei, MIC of chitosan was 2% for P. aeruginosa and 1I % for S. aureus. This study suggest that chitosan might be useful as an eyedrop.

• Journal of Life Science
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• v.22 no.5
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• pp.697-701
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• 2012

Activated protein C (APC) has an anticoagulant effect and a non-hemostatic effect such as regulation of cell metastasis and modulation of inflammation. In this study, we investigated whether APC could modulate apoptosis in cancer cells. Tumor necrosis factor (TNF)-${\alpha}$, cyclohexamide, and FAS markedly induced apoptosis in human renal carcinoma Caki cells. When Caki cells were pretreated with APC, the percentage of death receptor-induced apoptosis did not change. Furthermore, we checked the effect of APC on tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis in human glioma T98G and human breast carcinoma MDA231 cells. APC also had no effect on TRAIL-induced apoptosis in both cell lines. However, pretreatment with APC inhibited combination treatment (kahweol plus TRAIL and kahweol plus melatonin)-induced apoptosis and PARP cleavage in Caki cells. Taken together, our results suggest that APC can modulate anti-cancer therapeutic efficiency.

• Microbiology and Biotechnology Letters
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• v.41 no.3
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• pp.379-382
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• 2013

In order to investigate the anticancer activity of an anti-yeast substance (AYS), a proteoglycan produced by Rhanella aquatilis AY2000, the cytotoxicity of the AYS against cancer cells was determined in vitro. The AYS was not cytotoxic to the human Jurkat T cell or the mouse sarcoma 180 cell, but was cytotoxic to the human colon cancer TH20 cell. The AYS was increasingly cytotoxic against human colon cancer cells in a dose-dependent manner at range from 62.5 to 500 ${\mu}g/ml$. Anticancer activity by combination of the AYS and an anticancer agent was also determined. The anticancer agent combined with the AYS was shown to possess greater synergistic anticancer activity against human colon cancer cells, as compared with the anticancer agent alone.

• Journal of Digital Convergence
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• v.19 no.5
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• pp.207-214
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• 2021

Humans are environmentally exposed to various electromagnetic fields, but the evaluation of the harmfulness of electromagnetic field and the development of a system therefor are still incomplete. We aimed to develop a system for evaluating biohazard against electromagnetic fields, and to determine biohazard through the system. An extremely-low frequency magnetic field generator was designed and manufactured, and the output reliability of the device was verified. Using this device, the effect on the formation of cellular stress-granules and the cell cycle progression of cells exposed to high magnetic fields of 6 mT and 60 Hz was confirmed. As a result, exposure to high magnetic fields of 6 hr, 12 hr and 36 hr did not affect the formation of cell stress-induced granules and the cell division cycle. These results are an important basis for the determination of biohazard to the extremely-low frequency high magnetic field.

• Journal of Life Science
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• v.28 no.4
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• pp.454-464
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• 2018

Black soybeans are used as food sources as well as for traditional medicines because they contain an abundance of natural phenolic compounds. In this study, total phenolic contents (TPCs) of Korean black seed coat soybean varieties Socheongja (SCJ), Socheong 2 (SC2) and Cheongja 2 (CJ2) as well as their antioxidant capacities were investigated. Among them, TPCs were abundantly present in the order of CJ2$H_2O_2$-stimulated HaCaT human keratinocytes. Our results revealed that treatment with SCJ and SC2 prior to $H_2O_2$ exposure significantly increases the viability of HaCaT cells, indicating that the exposure of HaCaT cells to SCJ and SC2 conferred a protective effect against oxidative stress. SCJ and SC2 also effectively inhibited $H_2O_2$-induced apoptotic cell death through the blocking of mitochondrial dysfunction. SCJ and SC2 also attenuated the phosphorylation of Histone H2AX. Furthermore, they effectively induced the levels of thioredoxin reductase (TrxR) 1, a potent antioxidant enzyme, which is associated with the induction of nuclear transcription factor erythroid-2-like factor 2 (Nrf2); however, the protective effects of SCJ and SC2 were significantly reversed by Auranofin, a TrxR inhibitor. These results indicate that they have protective activity through the blocking of cellular damage related to oxidative stress via the Nrf2 signaling pathway. In conclusion, our study indicated that SCJ and SC2 might potentially serve as novel agents for the treatment and prevention of skin disorders caused by oxidative stress.

• Journal of Applied Biological Chemistry
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• v.63 no.3
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• pp.211-219
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• 2020

Quercetin is a polyphenol compound with excellent antioxidant and anti-inflammatory activity. However, little has been reported about the efficacy of quercetin to control psoriasis. Thus, we aimed to investigate the effect of quercetin to regulate psoriatic dermatitis with HaCaT cell lines activated by TNF-α and IL-17A, which are in vitro psoriasis skin models. When quercetin was treated with TNF-α-activated HaCaT cell line, inflammatory cytokine expressions such as IL-1α, IL-1β and IL-6 were reduced by 49.1±7.14, 42.8±8.16, and 34.5±2.52%, respectively. In addition, mRNA expression levels of IL-8 and CCL20 the chemokines that attract immune cells such as Th17 cells and dendritic cells to the inflammatory reaction site, were also reduced by 38.4±5.83 and 52.9±4.59% compared to the TNF-α treatment group. The expression of proteins KRT6A and KRT16, which was nonspecifically increased in psoriatic skin was also significantly suppressed. Moreover, phosphorylation of IκBα and STAT3 proteins activated by TNF-α was also significantly inhibited. After stimulating the HaCaT with IL-17A, known as another psoriasis-inducing cytokine, it was observed that IκBα mRNA expression decreased by 55.8±5.28%, and STAT3 phosphorylation was downregulated by 36.3±6.81%. Finally, after co-activation by TNF-α/IL-17A, quercetin inhibited all of IL-1α, IL-1β, IL-6, TNF-α and CCL20 gene expression. The above results strongly suggest that quercetin is a material that has not only anti-oxidant and anti-inflammatory activities, but also has an activity in improving psoriasis.

• The Journal of Internal Korean Medicine
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• v.22 no.2
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• pp.183-191
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• 2001

신경교세포에서 황금추출물이 반응성 산소기에 의한 세포 사망을 방지할 수 있는지를 확인하기 위하여 사람의 glioama 세포주인 A172 세포를 사용하여 $H_2O_2$의 독성작용에 대한 영향을 조사하였다. 세포 사망 정도는 tryptan blue exclusion과 MTT reduction assay로 평가하였다. $H_2O_2$는 세포 사망을 유도하였으며 또한 세포내 ATP 함량을 감소시켰으며, 이러한 효과는 황금 추출물에 의해 방지되었으며 그 효과는 농도 의존적으로 나타났다. $H_2O_2$에 의한 세포 사망은 잘 알려진 flavonoid인 quercetin과 철착염제인 phenanthroline에 의해 방지되었으나, 항산화제인 DPPD나 Trolox에 의해서는 영향을 받지 않았다. $H_2O_2$는 poly (ADP-ribose) polymerase를 활성화시켰으며, 이러한 효과는 황금, quercetin 및 phenanthroline에 의해 억제되었다. 황금 추출물은 유기산화제인 t-buthyhydroperoxide 및 중금속인 수은에 의한 세포 사망을 방지하였다. 이러한 실험 결과는 황금 추출물이 $H_2O_2$에 의한 세포 사망을 방지하며 그 효과는 황금의 flavonoid 성분이 철과 결합하여 $H_2O_2$로부터 hydroxy radical의 생성을 억제함으로써 나타나는 것으로 추측된다.

• Environmental Mutagens and Carcinogens
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• v.10 no.2
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• pp.135-145
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• 1990

Silver-binding nucleolar organizer regions (Ag-NORs)염색법을 이용하여 in vivo 및 in vitro에서 발암과정과 관련된 세포증식능을 검토하였다. A/J마우스에 benzo (a) pyrene을 투여하여 유발된 폐선종, 폐선암 및 Sprague-Dawley랫트에 dimethylbenz (a) anthracene투여에 의해 발생된 유선의 선암세포에서 Ag-NORs의 염색상태를 정상 조직과 비교하여 또한 정상마우스 섬유모세포인 NIH3T3에서의 Ag-NORs의 수 및 DNA 증식 억제물질인 caffeine에 의한 변화를 관찰하였다. 은친화성 NOR과련 단백질은 핵내 흑색의 반점으로 나타났으며 정상 폐조직의 세포당 Ag-NORs 수치는 0.87+0.01였으며 양성종양인 폐선종세포 및 악성종양인 폐선암세포에서는 각각 2.33+0.02, 2.56+0.45 정상 유선조직의 세포당 Ag-NORs수치는 1.21+0.16였으며 악성종양인 선암세포는 3.91+0.11로써 종양성 병변에서 유의한 증가를 보였다 (P<0.005).