• Journal of Life Science
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• v.26 no.4
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• pp.490-495
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• 2016

Brefeldin A (BFA), a lactone antibiotic isolated from the fungus Eupenicillium brefeldianum, inhibits the transport of secreted and membrane proteins from the endoplasmic reticulum (ER) to the Golgi apparatus. BFA disrupts Golgi function, the accumulation of unfolded proteins in ER, and the induction of ER stress. Prolonged ER stress induces apoptosis at least in part through the transcription factor C/EBP (CCAAT/enhancer binding protein) homologous protein (CHOP),which is activated by the unfolded protein response (UPR). In this paper, we demonstrate that BFA-induced endoplasmic reticulum stress leads to different CHOP expression in primary astrocyte cells and C6 glioma cells. BFA induced lower CHOP expression levels in primary astrocyte cells than in C6 glioma cells; however, other ER stress inducers (thapsigargin and tunicamycin) resulted in similar expression patterns in these two cell types. Interestingly, the three different ER stress inducers (BFA, thapsigargin, and tunicamycin) induced similar levels of CHOP mRNA expression in primary astrocyte cells. The ubiquitin-proteasome inhibitor MG132 also markedly up-regulated the BFA-mediated CHOP protein expression in primary astrocyte cells. BFA also induced higher proteasome activity in primary astrocyte cells than in C6 glioma cells. Taken together, our results suggest that higher proteasomal activity might down-regulate BFA-induced CHOP expression in primary astrocyte cells.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.4
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• pp.651-656
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• 2001

Ascorbic acid(AsA) is unevenly distributed throughout all body cells and fluids. Multiactivities of AsA in many biological systems and in various scientific fields were reported. In this study we aimed to clarify the inhibitory action of high concentration of AsA on the cell growth in 3T6 fibroblasts. The cells wee exposed to AsA at various concentration. It showed that 3T6 fibroblasts wee dead by the medium which contained AsA at the concentration higher than 0.5 mM. AsA caused hydrogen peroxide ($H_2O$$_2$) generation in a concentration dependent manner. These results suggested that the $H_2O$$_2$ was formed in the medium by AsA and acted as a cytotoxic gent. Moreover, it is supposed that hydroxyl radical (.OH) induced from $H_2O$$_2$also acetd as actively cytotoxic agent. This lethal effect of AsA causing the cell death was inhibited by the addition of catalase in the medium. Therefore, addition of AsA at the normal concentrations stimulate cell growth, but excess concentrations of AsA induce cell death.

• Applied Microscopy
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• v.37 no.4
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• pp.239-248
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• 2007

Alteration of temperature is one of cancer therapies. In general, severe hyperthermia(around $43^{\circ}C$) and hypothermia(around $18^{\circ}C$) trigger apoptosis through mitochondria, though the specific mechanism is still unknown. CC-t6 and GB-d1 cell lines, which were originally derived from human cholangiocarcinoma and gall bladder cancer, were established from a metastatic lymph node. To investigate the mechanism of metastatic cancer cell response to thermal stresses, hyperthermia($37^{\circ}C{\rightarrow}43^{\circ}C$) and hypothermia($37^{\circ}C{\rightarrow}17.4^{\circ}C$) were designed. Thermal stresses did not induce apoptosis but necrotic cell death. Any alterations of caspase-3, -9, cytochrome c, Bax, and Bcl-2 were not found in both hyperthermia and hypothermia exposed fells using western blot analysis. In the transmission electron microscopy, typical necrotic, but not apoptotic, changes were observed. These results suggest that temperature changes induce cell death through necrotic pathway in metastatic cancer in vitro, and it can be one of effective anticancer methods.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.1
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• pp.42-47
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• 2006

L-Ascorbic acid (AsA) is an essential nutrient for prevention of scurvy in humans, primates and guinea pigs that lack $L-gulono-\gamma-lactone$ oxidase which is required for the final step of AsA biosynthesis. AsA participates in various hydroxylation reactions involved in the biosynthesis of collagen. The purpose of this study is to clarify the role of AsA on collagen synthesis in 3T6 fibroblasts and primary cultured cells of chondrocytes. Cells were cultured in medium supplemented with catalase and AsA at various concentration. Supplement of AsA induced collagen synthesis in 3T6 fibroblasts and primary cultured cells of chondrocytes. The most remarkable induction of collagen synthesis by AsA was found in primary cultured chondrocytes. The content of collagen representing the amounts of extracellular matrix significantly increased in the cells of which growth was stimulated by AsA, while it decreased with increasing passage numbers of subculture in cells. It showed that the content of collagen decreased in the medium which contained AsA at the concentration higher than 5.0 mM. However, the contents of collagen to DNA were not different among various AsA concentrations. Supplementing with AsA resulted in enhancement of collagen formation and extracellular matrix. Therefore, there might be a Positive correlation between the activity of catalase and the AsA concentration. Moreover, it can be assumed that AsA stimulates the collagen synthesis by optimizing the cell-culture environment.

• 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.

• Development and Reproduction
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• v.8 no.1
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• pp.43-47
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• 2004

The present paper studied neurosecretory cell types and their seasonal secretory activity in the eyestalk of Palaemon macrodactylus. The samples were monthly collected in Nakdong estuary for one year. The eyestalk consisted of lamina ganglionaris, medulla externa medulla interna, and medulla terminaris. four types of neurosecretory, A-, B-, C- and D-cells are found in the eyestalk. The A-cells are located in the medulla externs. Althoush the B- and C-cells are located in the medulla interna and medulla terminalis, B-cells are predominant in medulla interna and C-cells are usually distributed in medulla terminaris. The size of D-cells are larger than other types of cells in size. The neurosecretory cells except D-cells show a remarkable change with month. The A-, B-, and C-cells are activated from March and April to July, and decreased at August.

• THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
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• v.3 no.1
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• pp.85-98
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• 1997

Oriental medicine as a candidate for effective cancer treatment recently gain positive concerns in fields of therapeutic oncology. that is why some herbal medicines have been empirically safer in toxicity than anticancer drugs used in western medicine, and to show excellent therapeutic efficacy in human trial. Thus, these effects by clinically applied-herbs have not yet fully demonstrated in experimental tumor model. This study was initiated to evaluate the antitumor effect of Insambaekhaptang as candidate of antitumor-herbal agent against B16 melanoma metastasized into C57BL/6 mice lung. In experiment to test whether Insambaekhaptang can directly kill cancer cells in vitro or not, Insambaekhaptang showed direct killing action in concentration or higher against B16 melanoma cells using MTT assay, and showed lower IC50. Another experiment to know whether Insambaekhaptang can inhibit growth and metastasis of cancer cell or not, Insambaekhaptang significantly inhibited Solid tumor by intraperiperal injected-melanoma and lung metastasis induced by intravenous injected-melanoma in inbred C57BL/6 mice. When quantitative survival time increasing, we could obtain results that increased 113% in treated by Insambaekhaptang. These results show that Insambaekhaptang can inhibit growth of B16 melanoma cells through various biological mechanisms.

• Radiation Oncology Journal
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• v.17 no.3
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• pp.223-229
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• 1999

Purpose : The expression pattern of c-jun by ionizing radiation according to cell growth state (exponential growth vs. stationary phase) and its relationship with cell cycle redistribution were investigated. Materials and Methods : The exponential growth phase (day 4) and stationary phase (day 9) cells were determined from cell growth curve according to the elapse of days in CaSki. The cells were irradiated using 6 MV X-ray with a dose of 2 Gy at a fixed dose rate of 3 Gy/min. Northern blot analysis was peformed with total cellular RNA and cell cycle distribution was analyzed using flow cytometry according to time-course after irradiation. Results : The maximum expression of c-jun occurred 1 hour after irradiation in both exponential growth and stationary phase cells. After then c-jun expression was elevated upto 6 hours in exponential growth phase cells, but the level decreased in stationary phase cells. Movements of cells from G0-G1 to S, G2-M phase after irradiation were higher in exponential growth phase than stationary phase. Conclusion : c-jun may be involved in the regulation of cellular proliferation according to the growth states after irradiation.

• Journal of Bio-Environment Control
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• v.4 no.2
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• pp.136-143
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• 1995

Using a PEG- dextran two phase partition method, plasma and intracellular membrane separated from microsomal membrane of canola (Brassica napus) leaves have been fractionated by centrifugation. $K^{+}$- ATPase specific activity in the plasma membrane (U$_2$ phase) of plants grown at $25^{\circ}C$ and 1$0^{\circ}C$ were 6.6 and 4.6 times, respectively that of the microsomal membrane. Plasma membrane had a lower cytochrome- c- oxidase specific activity than the microsomal membrane or intracellular membrane, while intracellular membrane (L$_2$ phase) had a high cytochrome-c- oxidase but little $K^{+}$- ATPase specific activity. The plasma membrane of canola grown at 1$0^{\circ}C$ had higher 18:3 to 18:2 (linolenic to linoleic acid) ratio (29.2% ) and higher degree of unsaturation than that grown at $25^{\circ}C$ The double bond index of plasma membrane from canola grown at 1$0^{\circ}C$ increased by 8.9% relative to canola grown at $25^{\circ}C$. Similar, intracellular membrane increased by 19.7% at 1$0^{\circ}C$. Canola grown at 1$0^{\circ}C$ was lower in chlorophyll contents (17.3%) than that grown at $25^{\circ}C$. These changes in fatty acid unsaturation were attributable largely to change in Cl8 fatty acid, with major changes occurring in linolenic acid (18 :3) which might have a physiological role of membrane to adaptation on low temperature.ure.

• Journal of Applied Biological Chemistry
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• v.64 no.1
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• pp.69-74
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• 2021

Chronic alcohol is responsible for oxidative stress and neurodegenerative diseases such as dementia. In the present study, we investigated the antioxidant activity and protective effects of seed of Carthamus tinctorius L. on ethanol-induced C6 glial cells. Antioxidant effect of seed of C. tinctorius L. was measured by scavenging activity of 1,1-diphenyl-2-prcrylhydrazy (DPPH), hydroxyl radical (·OH), superoxide radical, and nitric oxide. The seed of C. tinctorius L. extract showed significant radical scavenging activities in a concentration-dependent manner. In particular, it revealed strong DPPH and ·OH scavenging activity, displaying more than 80% at 500 and 100 ㎍/mL, respectively. Treatment of 500 mM ethanol to C6 glial cell led to decline of cell viability and elevation of reactive oxygen species (ROS) generation. However, seed of C. tinctorius L.-treated groups significantly increased cell viability and decreased ROS levels, compared to ethanol-induced control group. These results suggest that seed of C. tinctorius L. would have protective effect against neuronal oxidative stress induced by alcohol.