• Journal of Animal Science and Technology
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• v.46 no.4
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• pp.563-570
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• 2004

The insulin-like growth factor(IGF) system, consisting of IGFs-I and -II ligands and their receptors and six IGF-binding proteins(IGFBPs), plays an important role in survival, proliferation and differentiation of a variety of cell types. Lithium is a known modulator of survival and proliferation of many cell types in vitro. The present study was undertaken to investigate the relationship between LiCI-induced changes in cell survival and growth and the expression of the IGF system components in C6 rat glioma cell line which, besides IGF-I and its receptor, is known to express IGFBP-3 as its major IGF carrier. When C6 cells were cultured for 24h in the absence or presence of 2mM or 5mM LiCl in a 10% serwn-containing medium, the viability and the number of cells were not affected by added lithium. In 72-h culture, however, C6 cells clearly exhibited a dose-dependent response to added LiCl. The cells cultured for 72h in the presence of 0, 2mM and 5mM LiCl exhibited a typical mitotic, a growth-arrested and an apoptotic appearances, respectively. Moreover, the apoptotic cells were accompanied by reduced expression of IGF-I, IGF-I receptor and IGFBP-3 as examined by semi-quantitative reverse transcription-polymerase chain reaction. Interestingly, blockade of IGFBP-3 mRNA translation by addition of 101${\mu}M$ IGFBP-3 anti-sense oligodeoxyribonucleotide in serum-free, 24-h culture resulted in a decrease in the number of cells as well as relative abundance of the target mRNA. In summary, results suggest that the cytotoxic effect of lithium in C6 cell is likely to be mediated, in part, by suppression by this agent of the expression of the IGF system components. In this regard, IGFBP-3 may play at least a 'permissive' role in normal proliferation of this cell.

• Restorative Dentistry and Endodontics
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• v.34 no.6
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• pp.491-499
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• 2009

This study examined the influence of the storage methods on the viability of oral epithelial cells using conventional cell freezing storage, slow freezing preservation, rapid freezing preservation, and slow freezing preservation with a pressure of 2 Mpa or 3 Mpa. The cell viability was evaluated by cell counting, WST-1 and the clonogenic capacity after 6 days of freezing storage. After 6 days, the frozen cells were thawed rapidly, and the cell counting. WST-1, and clonogenic capacity values were measured and compared. 1. The results from cell counting demonstrated that conventional cryopreservation, slow freezing under a 2 Mpa pressure and slow freezing under a 3 Mpa pressure showed significantly higher values than slow freezing preservation and rapid freezing preservation (p < 0.05). 2. The results from the optical density by WST-1 demonstrated that slow freezing under a 2 Mpa pressure showed significantly higher values than slow freezing preservation and rapid freezing preservation (p<0.05). 3. The clonogenic capacity demonstrated that slow freezing under a 2 Mpa pressure showed significantly higher values than slow freezing preservation and rapid freezing preservation (p < 0.05).

• The Korean Journal of Physiology and Pharmacology
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• v.6 no.5
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• pp.235-239
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• 2002

It has been reported that lovastatin induced cell death and suppressed proliferation in various cell lines. In this study, we examined whether the cytotoxic effects of lovastatin could be prevented by Bcl-2 or $Bcl-_{XL}$ in C6 glial cells. Overexpression of human Bcl-2 or $Bcl-_{XL}$ prevented lovastatin $(25{\mu}M)-induced$ changes such as DNA fragmentation, chromatin condensation, disruption of cell membrane, and cleavage of poly (ADP-ribose) polymerase. Lovastatin-induced inhibition of cell proliferation was unaffected by Bcl-2 or $Bcl-_{XL}$ overexpression. These results suggest that Bcl-2 and $Bcl-_{XL}$ can prevent lovastatin-induced apoptosis in C6 glial cells, though the inhibition of proliferation remains unaffected by these proteins.

• Journal of the Korean Society of Radiology
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• v.14 no.2
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• pp.85-95
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• 2020

The filtration characteristics of H₂O-C₆H₁₂O₆ solution at cell membrane model in renal tubule which irradiated by high energy x-ray(linac 6MV) was investigated. The cell membrane model used in this experiment was a polysulfonated copolymerized membrane of m-phenylene-diamine(MPD) and trimesoyl chloride(TMC)-hexane. They were used to two cell membrane models(CM-1, CM-2). The cell membrane model composed of 0.5 wt% TMC-hexane solution(CM-2) had higher permeate flux(Jv) and rejection coefficient(R) than composed of 0.1 wt% TMC-hexane solution(CM-1). The permeate flux(Jv) and rejection coefficient(R) of H₂O-C₆H₁₂O₆ solution in two cell membrane models(CM-1, CM-2) were increased with increase of pressure drop and effective pressure difference. In this experiment range(pressure 1.5-4 MPa, temperature 36.5 ℃), permeate flux(Jv) of H₂O solvent in irradiated membrane was found to be decreased about 20-30 times than non-irradiated membrane, permeate flux(Jv) and rejection coefficient(R) of H₂O-C₆H₁₂O₆ solution in irradiated membrane was found to be decreased about 2-13 times, about 4-6 times than non-irradiated membrane, respectively. The concentration increase of H₂O-C₆H₁₂O₆ solution at cell membrane model significantly was increased at rejection coefficient(R), was decreased at permeate flux(Jv). As the filtration of H₂O-C₆H₁₂O₆ solution in cell membrane model were abnormal, cell damages were appeared at cell.

• Journal of Physiology & Pathology in Korean Medicine
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• v.24 no.6
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• pp.1004-1011
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• 2010

This study was designed to evaluate the protective effects of Dodamtanggami-bang (DDTG) on tunicamycin induced cell death by ER stress in C6 glial cells. Cell viability was measured by MTT assay and LDH release. Apoptosis was determined by caspase activity and flow cytometry in C6 glial cells. Expression of ER stress mediators including, GRP78 and CHOP proteins were measured by Western blot analysis. Tunicamycin induced the apoptosis of C6 glial cells, which was characterized as nucleic acid and caspase-3 activation, PARP cleavage, and sub-G0/G1 fraction of cell cycle increase. However, pretreatment with DDTG protected C6 glial cells from tunicamycin. Treatment with tunicamycin resulted in the increased the expression of GRP78 and CHOP protein and produced ROS generation. However, pretreatment with DDTG inhibited the ER stress pathway, including increase of the expression of GRP78, CHOP proteins in C6 glial cells treated with tunicamycin. Taken together, these data suggest that DDTG is able to protect C6 glial cells from tunicamycin with marked inhibition of ER stress.

• Biomolecules & Therapeutics
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• v.8 no.2
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• pp.140-146
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• 2000

Recently, we reported that immunostimulation of primary rat cortical astrocyte caused stimulation of glucose deprivation induced apoptotic cell death. To enhance the understanding of the mechanism of the potentiated cell death of clucose-deprived astrocyte by immunostimulation, we investigated the effect of immunostimulation on the glucose deprivation induced cell death of rat C6 glioma cells. Co-treatment of C6 glioma cells with lipopolysaccharide (LPS, $1\;{\mu}\textrm{g}/ml$) and interferon ${\gamma}(IFN{\gamma},\;100U/ml)$ is serum free condition caused marked elevationo f nitric oxide production ($>50\;{\mu}M$). In this condition, glucose deprivation caused significant release of lactate dehdrogenase (LDH) from C6 glioma cells while control cells did not show LDH release. To investigate whether elevated level of nitric oxide is responsible for the enhanced LDH release in glucose-deprived condition, C6 glioma cells were treated with 3-morphorinosydnonimine (SIN-1) and it was observed that SIN-1 caused increase in LDH release from glucose-deprived C6 glioma cells. Treatment of C6 glioma cells with $25\;{\mu}M$ of pyrrolidinedithiocarbamate (PDTC) which inhibit Nuclear factor kB (NF-kB) activation, caused complete inhibition of nitric oxide production. Treatment of C6 glioma cells with NO synthase inhibitors, $N^{G}$-nitro-L-arginine (NNA) or L-$N{\omega}$-nitro-L-arginine methyl ester (L-NAME), caused inhibition of nitric oxide production and also glucose deprivation induced cell death of cytokine-stimulated C6 glioma cells. In addition, diaminohydroxypyrimidine (DAHP, 5 mM) which inhibits the synthesis of tetrahydrobiopterine (BH4), one of essential cofactors for iNOS activity, caused complete inhibition of NO production from immunostimulated C6 glioma cells. The results from the present study suggest that immunostimulation causes potentiation of glucose deprivation induced death of C6 glioma cells which is mediated at least in part by the increased production of nitric oxide. The vulnerability of immunostimulated C6 glioma cells to hypoglycemic insults may implicate that the elevated level of cytokines in various ischemic and neurodegenerative diseases may play a role in their pathogenesis.

• The Journal of Korean Medicine
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• v.22 no.3
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• pp.63-73
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• 2001

Objectives : The objective of the current study is to determine the protective effect of Ukyium(Yougui-yin) on the apoptosis induced by zinc. Methods : Zinc is known to generate reactive oxygen species (ROS), including superoxide anion ($O_2$) and hydrogen peroxide ($H_2O_2$), which eventually contribute to cytotoxicity in a variety of cell types. We investigated the viablity of cells, $H_2O_2$ generation, chromatin condensation and nuclear fragmentation in Hoechst dye staining and $IkB-{\alpha}$ degradation in C6 glial cells of $ZnCl_2$ between pretreatment- and not pretreatment-group with Ukyium. The former methods were researched by Time- and Dose-dependent manners. Results : We demonstrated that pretreatment with Ukyium prevented zinc-induced cell death of C6 glial cells and apoptotic characteristics including chromatin condensation and nuclear fragmentation. Ukyium also prevented $H_2O_2-induced$ cell death. We further confirmed that Ukyium decreased zinc-induced generation of $H_2O_2$ and inhibited degradation of $IkB-{\alpha}$ by zinc in C6 glial ceHs. Conclusions : These data indicated that Ukyium (Yougui-yin) prevents zinc-induced apoptotic death of C6 glial cells via inhibition of ROS generation, such as $H_2O_2$ as well as inhibition of $IkB-{\alpha}$ degradation.

• Biomedical Science Letters
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• v.12 no.3
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• pp.261-265
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• 2006

Toxic effect of Hexavalent chromium $(CrO_3)$ on various cells and organs has been well recognized. However, the mechanism and degree of cytotoxicity of $CrO_3$ remain unclear. This study was performed to examine the cytotoxicity of $CrO_3$ on $C_6$ glioma cells by measuring cell viability. The XTT assay, one of the sensitive methods to determine the cell viability, was taken to examine the viability of glioma cells treated with $CrO_3$. In this study, not only decreased the number of glioma cells but morphologic changes of them were noted and cell viability decreased in a time and dose-dependent manner after treated with various concentrations of $CrO_3$ for 48hours. $IC_{90}\;and\;IC_{50}$ values in XTT assay were determined at $25{\mu}M\;and\;55{\mu}M$ $CrO_3$, respectively. These results suggest that Hexavalent chromium has a highly cytotoxic effect and has a time and dose-dependent cytotoxicity on $C_6$ glioma cells.

• The Journal of Internal Korean Medicine
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• v.31 no.1
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• pp.54-65
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• 2010

Objective : The water extract of Chungsimyeonja-eum (CSYJE) has traditionally been used in treatments of heart diseases and brain diseases in Oriental medicine. However, little is known about the mechanism by which CSYJE protects neuronal cells from injury damages. Therefore, in this study we attempted to elucidate the mechanism of the cytoprotective effect of the CSYJE extract on glutamate-induced C6 glial cell death. Methods : Cultured cells were pretreated with CSYJE and exposed to glutamate, cell damage was assessed by using MTT assay and propidium iodide (PI), probe 2',7'-dichlorofluorescein diacetate (DCF-DA) staining. Western blotting was performed using anti-procaspase-3 and anti-PARP, respectively. Result : We determined the elevated cell viability by CSYJE extract on glutamate-induced C6 glial cell death. Glutamate induced DNA fragmentation on C6 glial cells but pre-treatment with CSYJE inhibited DNA fragmentation. One of the main mediators of glutamate-induced cytotoxicity was known to generation of reactive oxygen species (ROS). Pre-treatment with CSYJE inhibited this ROS generation from glutamate-stimulated C6 glial cells. Also, we identified that the ROS-induced DCF-DA green fluorescence was reduced by CSYJE pre-treatment. The critical markers of apoptotic cell death are the cleavages of procaspase-3 protease and PARP proteins, so we checked the expression level and cleavages of procaspase-3 protease and PARP proteins. Glutamate-treated C6 glial cells showed the cleavages of procaspase-3 protease and PARP proteins and followed the reduction of expression of these proteins. Conclusion : These findings indicate that CSYJE may prevent cell death from glutamate-induced C6 glial cell death by inhibiting the ROS generation and procaspase-3 and PARP expression.

• Microbiology and Biotechnology Letters
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• v.29 no.4
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• pp.227-233
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• 2001

To maximize astaxanthin (3,3'-dihydroxy-$\beta\beta$'carotene-44'-dione) production by high density Haematococcus pluvialis cultures, various, media were examined Among tested media, \`Hong Kong Medium and Modified Bolds Basal Medium showed the best result for cell growth ( $2.0$\times$10^{ 6}$cells /mL) and for astaxanthin content per cell (9.7 mg astaxanthin mg/g cell), respectively, Maximum astasanthin concentration of 6.1mL was obtained at pH 7.5, $20^{\circ}C$~$25^{\circ}C$ Deficiencies of nitrogen source($NaNO_3$ and proteose-peptone) found to simulate astaxanthin formation Relatively low light inten- sity of $60\mu$E ($\m^2$s) was sutiable for vegetative cell growth while higher light intensity was required for higher astaxanthin accumulation.