• Applied Biological Chemistry
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• 제34권3호
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• pp.231-234
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• 1991

동물세포에 미치는 웅담의 영향을 조사하기 위해서 원숭이 kidney cell 유래의 COS-7 cell과 hybridoma cell(murine myeloma cell과 rat의 spleen cell을 융합)을 가지고 이들 세포의 생육과 단백질 발현기작에 미치는 영향을 조사했다. COS-7 cell과 hybridoma cell을 웅담이 첨가된 10% FCS DMEM complete medium에서 78시간 배양한 결과 COS-7 cell에는 거의 영향을 미치지 않았으나 myeloma cell과 spleen cell과의 융합세포는 48시간내에 거의 모든 세포가 사멸됐다. 또한 cDNA를 COS-7 cell에 transfection에서 발현되는 단백질양을 조사한바 웅담이 첨가된 배지에서의 단백질 생산량이 첨가되지 않은 배지에서 보다 $30{\sim}40%$ 감소되었다.

• Preventive Nutrition and Food Science
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• 제12권1호
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• pp.7-10
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• 2007

Theaflavins (TF) and thearubigins (TR) were separated from Korean microbially fermented tea leaves. Contents of TF (74.4 $\mu$M/g) and TR (37.2%) were higher than reported for black tea fermented by oxidase. Antioxidant activities of TF, TR and EGCG were analyzed and protective effects of COS-7 cells against copper and cadmium-induced toxicity were investigated. TF and TR exhibited good inhibition rates of about 85$\sim$90% for antioxidant and scavenging activities of free radicals and protected COS-7 cells against apoptosis or damage caused by stress, such as cadmium and copper-oxidative injury, free radicals etc. These results indicate that TF, TR and EGCG have antioxidant and scavenging activities against free radicals and protect COS-7 cells from Cu, Cd induced injury.

• Journal of Dental Anesthesia and Pain Medicine
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• 제16권3호
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• pp.175-184
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• 2016

Background: This study investigated the effect of remifentanil pretreatment on Cos-7 cells exposed to oxidative stress, and the influence of remifentanil on intracellular autophagy and apoptotic cell death. Methods: Cells were divided into 4 groups: (1) Control: non-pretreated cells were incubated in normoxia (5% $CO_2$, 21% $O_2$, and 74% $N_2$). (2) $H_2O_2$: non-pretreated cells were exposed to $H_2O_2$ for 24 h. (3) RPC+$H_2O_2$: cells pretreated with remifentanil were exposed to $H_2O_2$ for 24 h. (4) 3-MA+RPC+$H_2O_2$: cells pretreated with 3-Methyladenine (3-MA) and remifentanil were exposed to $H_2O_2$ for 24 h. We determined the cell viability of each group using an MTT assay. Hoechst staining and FACS analysis of Cos-7 cells were performed to observe the effect of remifentanil on apoptosis. Autophagy activation was determined by fluorescence microscopy, MDC staining, and AO staining. The expression of autophagy-related proteins was observed using western blotting. Results: Remifentanil pretreatment increased the viability of Cos-7 cells exposed to oxidative stress. Hoechst staining and FACS analysis revealed that oxidative stress-dependent apoptosis was suppressed by the pretreatment. Additionally, fluorescence microscopy showed that remifentanil pretreatment led to autophagy-induction in Cos-7 cells, and the expression of autophagy-related proteins was increased in the RPC+$H_2O_2$ group. Conclusions: The study showed that remifentanil pretreatment stimulated autophagy and increased viability in an oxidative stress model of Cos-7 cells. Therefore, we suggest that apoptosis was activated upon oxidative stress, and remifentanil preconditioning increased the survival rate of the cells by activating autophagy.

• 대한치과마취과학회지
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• 제14권1호
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• pp.49-56
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• 2014

Background: Propofol (2.6-diisopropylphenol) is a widely used intravenous anesthetic agent for the induction and maintenance of anesthesia during surgeries and sedation for ICU patients. Propofol has a structural similarity to the endogenous antioxidant vitamin E and exhibits antioxidant activities.13) However, the mechanism of propofol on hypoxia/reoxygenation (H/R) injury has yet to be fully elucidated. We investigated how P-PostC influences the autophagy and cell death, a cellular damage occurring during the H/R injury. Methods: The groups were randomly divided into the following groups: Control: cells were incubated in normoxia (5% CO2, 21% O2, and 74% N2) without propofol treatment. H/R: cells were exposed to 24 h of hypoxia (5% CO2, 1% O2, and 94% N2) followed by 12 h of reoxygenation (5% CO2, 21% O2, and 74% N2). H/R + P-PostC: cells post-treated with propofol were exposed to 24 h of hypoxia followed by 12 h of reoxygenation. 3-MA + P-PostC: cells pretreated with 3-MA and post-treated propofol were exposed to 24 h of hypoxia followed by 12 h of reoxygenation Results: The results of our present study provides a new direction of research on mechanisms of propofol-mediated cytoprotection. There are three principal findings of these studies. First, the application of P-PostC at the onset of reoxygenation after hypoxia significantly increased COS-7 cell viability. Second, the cellular protective effect of P-PostC in H/R induced COS-7 cells was probably related to activation of intra-cellular autophagy. And third, the autophagy pathway inhibitor 3-MA blocked the protective effect of P-PostC on cell viability, suggesting a key role of autophagy in cellular protective effect of P-PostC. Conclusions: These data provided evidence that P-PostC reduced cell death in H/R model of COS-7 cells, which was in agreement with the protection by P-PostC demonstrated in isolated COS-7 cells exposed to H/R injury. Although the this study could not represent the protection by P-PostC in vivo, the data demonstrate another model in which endogenous mechanisms evoked by P-PostC protected the COS-7 cells exposed to H/R injury from cell death.

• Molecules and Cells
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• 제22권1호
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• pp.113-118
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• 2006

Thioredoxin reductase (TrxR), a component of the redox control system involving thioredoxin (Trx), is implicated in defense against oxidative stress, control of cell growth and proliferation, and regulation of apoptosis. In the present study a stable transfectant was made by introducing the vector pcDNA3.0 harboring the fission yeast TrxR gene into COS-7 African green monkey kidney fibroblast cells. The exogenous TrxR gene led to an increase in TrxR activity of up to 3.2-fold but did not affect glutathione (GSH) content, or glutaredoxin and caspase-3 activities. Levels of reactive oxygen species (ROS), but not those of nitric oxide (NO), were reduced. Conversely, 1-chloro-2,4-dinitrobezene (CDNB), an irreversible inhibitor of mammalian TrxR, enhanced ROS levels in the COS-7 cells. After treatment with hydrogen peroxide, the level of intracellular ROS was lower in the transfectants than in the vector control cells. These results confirm that TrxR is a crucial determinant of the level of cellular ROS during oxidative stress as well as in the normal state.

• Applied Microscopy
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• 제43권3호
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• pp.117-121
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• 2013

Mitochondrion is an important intracellular organelle controlling energy production essential for cell survival. In addition, it is closely related to cellular apoptosis and necrosis. Linear, branched, circular, and ball-shaped mitochondria have been reported. Recent research suggests that mitochondrial morphology may reflect functional status of the cell. In this study, we investigated the density and ratio of the each morphological categories of mitochondria in a few normal cultured cells; astrocyte, HeLa and COS7 cells, of which metabolic activities are different, with high voltage electron microscopy. The absolute number and relative number per unit area of mitochondria was largest in astrocyte. But, the proportion of different mitochondrial shape was similar among cells. These results shows the numerical profiles but not morphological profiles of mitochondria are related to the metabolic activity of each cell line.

• Journal of Dental Anesthesia and Pain Medicine
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• 제17권1호
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• pp.37-46
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• 2017

Background: In oxidative stress, reactive oxygen species (ROS) production contributes to cellular dysfunction and initiates the apoptotic cascade. Autophagy is considered the mechanism that decreases ROS concentration and oxidative damage. Propofol shows antioxidant properties, but the mechanisms underlying the effect of propofol preconditioning (PPC) on oxidative injury remain unclear. Therefore, we investigated whether PPC protects against cell damage from hydrogen peroxide ($H_2O_2$)-induced oxidative stress and influences cellular autophagy. Method: COS-7 cells were randomly divided into the following groups: control, cells were incubated in normoxia (5% $CO_2$, 21% $O_2$, and 74% $N_2$) for 24 h without propofol; $H_2O_2$, cells were exposed to $H_2O_2$ ($400{\mu}M$) for 2 h; $PPC+H_2O_2$, cells pretreated with propofol were exposed to $H_2O_2$; and 3-methyladenine $(3-MA)+PPC+H_2O_2$, cells pretreated with 3-MA (1 mM) for 1 h and propofol were exposed to $H_2O_2$. Cell viability was determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide thiazolyl blue (MTT) reduction. Apoptosis was determined using Hoechst 33342 staining and fluorescence microscopy. The relationship between PPC and autophagy was detected using western blot analysis. Results: Cell viability decreased more significantly in the $H_2O_2$ group than in the control group, but it was improved by PPC ($100{\mu}M$). Pretreatment with propofol effectively decreased $H_2O_2$-induced COS-7 cell apoptosis. However, pretreatment with 3-MA inhibited the protective effect of propofol during apoptosis. Western blot analysis showed that the level of autophagy-related proteins was higher in the $PPC+H_2O_2$ group than that in the $H_2O_2$ group. Conclusion: PPC has a protective effect on $H_2O_2$-induced COS-7 cell apoptosis, which is mediated by autophagy activation.

• Journal of Pharmaceutical Investigation
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• 제25권2호
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• pp.137-143
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• 1995

The peptide transporter can be utilized for improving the bioavailability of compounds that are poorly absorbed. Characterization of the dipeptide uptake into the human intestinal epithelial cells, HT-29 was investigated. The uptake of tritiated glycylsarcosine $([^3H]-Gly-Sar,\;0.1\;{\mu}Ci/ml)$ was measured in confluent or subconfluent HT-29, Caco-2, and Cos-7 cells. Uptake medium was the Dulbecco's Modified Eagle's Media (DMEM) adjusted to pH 6.0. Both HT-29 and Caco-2 cells expressed the dipeptide transporter significantly (p<0.005) but Cos-7 did not. Certain portions of passive uptake were observed in all three cell lines. Uptake of Gly-Sar was largest at 7 days after plating HT-29 cells with significant inhibition with 25 mM cold Gly-Sar (p<0.05). but expression ratio of the dipeptide transporter was 0.7, suggesting lower expression. The effect of pH on Gly-Sar uptake was not significant in the range of pH 6 to 8. Gly-Sar uptake was also inhibited with 50 mM carnosine, 25 mM Gly-Sar, and 35 mM cephalexin significantly (p<0.05). From above results the dipeptide transporter was expressed well in HT-29 cells and was similar to that in the small intestine, suggesting that large amounts of mRNA of the transporter from the cells can be obtained.

• Toxicological Research
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• 제27권1호
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• pp.25-29
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• 2011

The cytochrome P450 (P450, CYP) are the superfamily of heme-containing monooxygenase enzymes, found throughout all nature including mammals, plants, and microorganisms. Mammalian P450 enzymes are involved in oxidative metabolism of a wide range of endo- and exogenous chemicals. Especially P450s involved in drug metabolisms are important for drug efficacy and polymorphisms of P450s in individuals reflect differences of drug responses between people. To study the functional differences of CYP2A6, CYP2D6, and CYP4A11 variants, we cloned the four CYP2A6, three CYP2D6, and three CYP4A11 variants, which were found in Korean populations, in mammalian expression vector pcDNA by PCR and examined their expressions in COS-7 mammalian cells using immunoblots using P450 specific polyclonal antibodies. Three of four CYP2A6, two of three CYP4A11, and two of three CYP2D6 variants showed expressions in COS-7 cells but the relative levels of expressions are remarkably different in those of each variants. Our findings may help to study and explain the differences between functions of CYP variants and drug responses in Korean populations.

• 한국식품영양과학회지
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• 제33권2호
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• pp.236-243
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• 2004

양식넙치의 세균성 질병의 원인균주인 Vibrio sp., Edwardsiella tarda 및 Streptococcus sp.를 제주산 양식 넙치로부터 직접 분리하였으며, 이들 세균에 대하여 키토산 및 분자량 크기에 따라 분획된 3종류의 키토산올리고당(HMW-COS, MMW-COS, LMW-COS)의 항균활성을 검토하였다. 키토산과 HMW-COS는 모든 세균에 대한 항균활성이 우수하였으며, 특히 Vibrio sp.과 Sfreptococcus sp.에 대해서 높은 항균활성을 나타내었다. 이들에 대한 결과는 키토산의 항균활성은 분자량에 따라 크게 의존한다는 사실을 보여주었다 E.tarda에 대한 키토산 및 HMW-COS의 항균활성은 처리시간을 증가시킴으로써 항균활성이 증가함을 보였으며, 이들의 항균기 작을 조사하기 위 한 SEM의 관찰에서, 세균들은 키토산에 의해 응집되어 서로 엉켜있는 형태를 보여주고 있었다. 이러한 현상은 키토산 및 HMW-COS가 세균의 증식을 명확하게 억제하고 있음을 보여주는 증거라 할 수 있다. 이것은 지금까지 여러 보고에서 밝혀진 키토산의 항균활성 메카니즘과 일치하는 것이라 판단된다.