• Journal of Life Science
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• v.26 no.12
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• pp.1383-1391
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• 2016

Anti-estrogen drugs such as tamoxifen have been used for treating patients with ER-positive, early breast cancer. However, resistance to anti-estrogen treatment is inevitable in most patients. Breast cancer anti-estrogen resistance-3 (BCAR3) has been identified as the protein responsible for the induction of tamoxifen resistance in estrogen-dependent human breast cancer. We have previously reported that BCAR3 regulates the cell cycle progression and the signaling pathway of EGF and insulin leading to DNA synthesis. In this study, we investigated the functional role of BCAR3 in regulating c-Jun transcription in non-tumorigenic human breast epithelial MCF-12A cells. A transient transfection of BCAR3 increased both the mRNA and protein of c-Jun expression, and stable expression of BCAR3 increased c-Jun protein expression. The overexpression of BCAR3 directly activated the promoter of c-jun, AP-1, and SRE but not that of $NF-{\kappa}B$. Furthermore, single-cell microinjection of BCAR3 expression plasmid in the cell cycle-arrested MCF-12A cells induced c-Jun protein expression, and co-injection of dominant negative mutants of Ras, Rac, and Rho suppressed the transcriptional activity of c-Jun in the presence of BCAR3. Furthermore, stable expression of BCAR3 increased the proliferation of MCF-12A cells. The microinjection of inhibitory materials such as anti-BCAR3 antibody and siRNA BCAR3 inhibited EGF-induced c-Jun expression but did not affect IGF-1 induced upregulation of c-Jun. Taken together, we propose that BCAR3 plays a crucial role in c-Jun protein expression and cell proliferation and that small GTPases (e.g., Ras, Rac, and Rho) are required for the BCAR3-mediated activation of c-Jun expression.

• Journal of Life Science
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• v.30 no.2
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• pp.211-220
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• 2020

The activity of CAR can be regulated not only by ligand binding but also by phosphorylation of regulatory factors involved in extracellular signaling pathways, cross-talk interactions with transcription factors, and the recruitment, degradation, and expression of coactivators and corepressors. This regulation of CAR activity can in turn have effects on the control of diverse physiological homeostasis, including xenobiotic and energy metabolism, cellular proliferation, and apoptosis. CAR is phosphorylated by the ERK1/2 signaling pathway, which causes formation of a complex with Hsp-90 and CCRP, leading to its cytoplasmic retention, whereas phenobarbital inhibits ERK1/2, which causes dephosphorylation of the downstream signaling molecules, leading to the recruitment to CAR of the activated RACK-1/PP2A components for the dephosphorylation, nuclear translocation, and the transcriptional activation of CAR. Activated CAR cross-talks with FoxO1 to induce inhibition of its transcriptional activity and with PGC-1α to induce protein degradation by ubiquitination, resulting in the transcriptional suppression of PEPCK and G6Pase involved in gluconeogenesis. Regulation by CAR of lipid synthesis and oxidation is achieved by its functional cross-talks, respectively, with PPARγ through the degradation of PGC-1α to inhibit expression of the lipogenic genes and with PPARα through either the suppression of CPT-1 expression or the interaction with PGC-1α each to induce tissue-specific inhibition or stimulation of β-oxidation. Whereas CAR stimulates cellular proliferation by suppressing p21 expression through the inhibition of FoxO1 transcriptional activity and inducing cyclin D1 expression, it suppresses apoptosis by inhibiting the activities of MKK7 and JNK-1 through the expression of GADD45B. In conclusion, CAR is involved in the maintenance of homeostasis by regulating not only xenobiotic metabolism but also energy metabolism, cellular proliferation, and apoptosis through diverse cross-talk interactions with extracellular signaling pathways and intracellular regulatory factors.

• Applied Microscopy
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• v.35 no.3
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• pp.165-176
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• 2005

Studies on molecular plasticity of Bermann glia (BG) after harmaline-induced Purkinje cell (PC) degeneration in the rat cerebellum. The intimate structural relationship between BG and PC, evidenced by the sheathing of the PC dendrites by veil-like process from the BG has been suggestive of the close functional relationship between these two cell types. However, little is known about metabolic couplings between these cells. This study designed to investigate molecular plasticity of BG in the rat cerebellum in which PCs were chemically ablated by harmaline treatment. Immunohistochemical examination reveals that harmaline induced PC degeneration causes a marked glial reaction in the cerebellum with activated BG and microglia aligned in parasagittal stripes within the vermis. In these strips, activated BG were associated with upregulaion of metallotheionein, while GLAST and was down regulated, as compared with nearby intact area where both BG are in contact with PCs. The data from this study demonstrate that BG can change their phenotypic expression when BG loose their contact with PCs. It is conceivable that activated BG may upregulate structural proteins, metallothionein expression to use for their proliferation and hypertrophy; metallothionein expression to cope with oxidative stress induced by PC degeneration and microglial activation. On the contrary, BG may down regulated expression of GLAST because sustained loss of contact with PCs would eliminate the necessity for the cellular machinery involved glutamate metabolism. In conclusion, BG might respond man to death of PCs by undergoing a change in metabolic state. It seems possible that signaling molecules released from PCs regulates the phenotype expression of BG. Also ultrastructures in the organelles of normal PC and BG are distinguished by mitochondrial appearance, and distributed vesicles at the synaptic area in the cytoplasm.

• Tuberculosis and Respiratory Diseases
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• v.58 no.1
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• pp.43-53
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• 2005

Emphysema is characterized by air space enlargement and alveolar destruction. The mechanism responsible for the development of emphysema was thought to be protease/antiprotease imbalance and oxidative stress. A very recent study shows that alveolar cell apoptosis causes lung destruction and emphysematous changes. Thus, this study was performed to support the evidence for the role of apoptosis in the development of emphysema by characterizing cigarette smoke extract (CSE)-induced apoptosis in A549 (type II pneumocyte) lung epithelial cells. CSE induced apoptosis at low concentration (10% or less) and both apoptosis and necrosis at high concentration (20%). Apoptosis was demonstrated by DNA fragmentation using FACScan for subG1 fraction. Discrimination between apoptosis and necrosis was done by morphologic analysis using fluorescent microscopy with Hoecst 33342/propium iodide double staing and electron microscopy. Cytochrome c release was confirmed by using immunofluorescence with monoclonal anti-cytochrome c antibody. However, CSE-induced cell death did not show the activation of caspase 3 and was not blocked by caspase inhibitors. This suggests that CSE-induced apoptosis might be caspase-independent apoptosis. CSE-induced cell death was near completely blocked by N-acetylcystein and bcl-2 overexpression protected CSE-induced cell death. This results suggests that CSE might induce apoptosis through intracellular oxidative stress. CSE also activated p53 and functional knock-out of p53 using stable overexpression of HPV-E6 protein inhibited CSE-induced cell death. The characterization of CSE-induced cell death in lung epithelial cells could support the role of lung cell apoptosis in the pathogenesis of emphysema.

• Journal of Ginseng Research
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• v.30 no.3
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• pp.117-127
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• 2006

Ginseng is a medicinal herb widely used in Asian countries. Dendritic cells(DCs) play a pivotal role in the initiation of T cell-mediated immune responses, making them an attractive cellular adjuvant for use in cancer vaccines. In this study, we examined the effects of Red-ginseng(water extract, edible and fermented ethyl alcohol extract, crude saponin) on the DCs phenotypic and functional maturation. Immature DCs were cultured in the presence of GM-CSF and IL-4, and the generated immature DCs were stimulated by water extract, edible and fermented ethyl alcohol extract, crude saponin and LPS, respectively, for 24hours. The expression of surface co-stimulatory molecules, including MHC(major histocompatibility complex) class II, CD40, CD80 and CD86, was increased on DCs that were stimulated with crude saponin, but antigen-uptake capacity was decreased. The antigen-presenting capacity of Red-ginseng extracts-treated DCs as analyzed by allogeneic T cells proliferation and IL-2, $IFN-{\gamma}$ production was increased. Furthermore, $CD4^+$ and $CD8^+$ syngeneic T cell(OVA-specific) proliferation and $IFN-{\gamma}$ production was significantly increased. However, $CD4^+$ syngeneic T cell secreted higher levels of IL-2 in responding but not $CD8^+$ syngeneic T cell. These results indicate the immunomodulatory properties of Red-ginseng extracts, which might be therapeutically useful in the control of cancers and immunodeficient diseases through the up-regulation of DCs maturation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.11
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• pp.1700-1707
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• 2015

The effects of drying temperature on drying characteristics of soybeans with different grain sizes [6.0 (S), 7.5 (M), and 9.0 mm (L) (${\pm}0.2$)] with 25.0% (${\pm}0.8$) initial moisture content were studied. Drying temperatures varied at 25, 35, and $45^{\circ}C$, with a constant air velocity (13.2 m/s). Thin-layer drying models were applied to describe the drying process of soybeans. The Midilli-Kucuk model showed the best fit ($R^2$ >0.99). Based on the model parameters, drying time to achieve the target moisture content (10%) was successfully estimated. Drying time was strongly dependent on the size of soybeans and the drying temperature. The effective moisture diffusivity ($D_{eff}$) was estimated by the diffusion model based on Fick's second law. $D_{eff}$ values increased as grain size and drying temperature increased due to the combined effect of high temperatures and high drying rates, which promote compact tissue. Deff values of S, M, and L estimated were in the range of $0.83{\times}10^{-10}$ to $1.51{\times}10^{-10}m^2/s$, $1.17{\times}10^{-10}$ to $2.17{\times}10^{-10}m^2/s$, and $1.53{\times}10^{-10}$ to $2.95{\times}10^{-10}m^2/s$, respectively, whereas activation energy ($E_a$) based on drying temperature showed no significant differences in the size of soybeans.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.5
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• pp.537-544
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• 2017

In this study, the anti-inflammatory effect of Polyopes affinis ethanol extract (PAEE) was investigated using LPS-stimulated RAW 264.7 cells and a croton oil-induced ICR mice model. Treatment with PAEE significantly reduced production of nitric oxide (NO) and pro-inflammatory cytokines [interleukin (IL)-6, tumor necrosis factor $(TNF)-{\alpha}$, and $IL-1{\beta}$] in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. PAEE treatment also reduced expression of inducible NO synthase, cyclooxygenase-2, nuclear $factor-{\kappa}B$, and mitogen-activated protein kinases in LPS-stimulated RAW 264.7 cells. In the croton oil-induced ear edema test, application of PAEE (10~250 mg/kg body weight) reduced ear edema in a dose-dependent manner, and PAEE treatment at 50 mg/kg body weight showed similar inhibitory effects compared with prednisolone (10 mg/kg body weight). Histological analysis revealed reduced dermal thickness and lower number of infiltrated mast cells. These results suggest that PAEE might be used as a promising anti-inflammatory agent for inhibition of LPS-induced inflammation and ear edema formation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.3
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• pp.269-275
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• 2008

The avocado is a widely grown and consumed fruit that is high in nutrients and low in calories, sodium, and fats. In this study, antioxidant activities and induction of apoptosis by methanol extracts from sarcocarp, seed and peel of avocado were investigated in vitro. Contents of total polyphenols in methanol extracts from sarcocarp, seed and peel were 13.89, 137.12 and $223.45{\mu}g/mg$ respectively. Radical-scavenging activities of the methanol extracts were examined by using ${\alpha},{\alpha}$-diphenyl-${\beta}$-picrylhydrazyl (DPPH) radicals and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) assay. The methanol extracts from the peel of avocado showed higher scavenging activities against DPPH, ABTS than those from sarcocarp and seed. Apoptosis in MDA-MB-231 cells mediated by the methanol extracts of avocado was associated with the increase of activation of caspase-3 and caspase-3 target protein, PARP. Therefore, with more researches on identification and action mechanism of active compounds, the methanol extracts from peel and seed of avocado is expected to be a natural source for the developments of functional food and medical agents to prevent human breast cancer.

• Tuberculosis and Respiratory Diseases
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• v.44 no.3
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• pp.583-591
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• 1997

The functional derangement of skeletal muscles which may be attributed to chronic hypoxia has been accepted as a possible mechanism of exercise impairment in patients with chronic obstructive pulmonary disease (COPD). The metabolic changes in skeletal muscle in patients with COPD are characterized by impaired oxidative phosphorylation, early activation of anaerobic glycolysis and excessive lactate and hydrogen ion production with exercise. But the cause of exercise limitation in patients with chronic lung disease without hypoxia has not been known. In order to evaluate the change in the skeletal muscle metabolism as a possible cause of the exercise limitation in chronic lung disease patients without hypoxia, we compared the muscular metabolic data of seven male patients which had been derived from noninvasive $^{31}P$ magnetic resonance spectroscopy(MRS) with those of five age-matched normal male control persons. $^{31}P$ MRS was studied during the sustained isometric contraction of the dominant forearm flexor muscles up to the exhaustion state and the recovery period. Maximal voluntary contraction(MVC) force of the muscle was measured before the isometric exercise, and the 30% of MVC force was constantly loaded to each patient during the isometric exercise. There were no differences of intracellular pH (pHi) and inorganic phosphate/phosphocreatine(Pi/PCr) at baseline, exhaustion state and recovery period between two groups. But pHi during the exercise was lower in patients group than the control group (p < 0.05). Pi/PCr during the exercise did not show significant difference between two groups. These results suggest that the exercise limitation in chronic lung disease patients without hypoxia also could be attributed to the abnormalities in the skeletal muscle metabolism.

• Journal of Life Science
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• v.13 no.3
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• pp.314-323
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• 2003

The purpose of this study was to examine the effects of xenobiotic nuclear receptors, CAR, SXR, and PPAR${\gamma}$ on the transcriptional activity of estrogen receptor in human breast cancer cell lines and compare with those in human hepatoma cell line. Two different breast cancer cell lines, MCF-7 and MDA-MB-231 were cultured and effects of CAR, SXR, and PPAR${\gamma}$ on the ER-mediated transcriptional activation of synthetic (4ERE)-tk-luciferase reporter gene were analyzed. Consistent with the previous report, CAR significantly inhibited ER-mediated transactivation and SXR repressed modestly whereas the PPAR${\gamma}$ did not repress the ER-mediated transactivation. However, in breast cancer cells neither of the xenobiotic receptors repressed the ER-mediated transactivation. Instead, they tend to increase the transactivation depending on the cell type and xenobiotic nuclear receptors. In MCF-7, SXR but neither CAR nor PPAR${\gamma}$ slightly increased ER-mediated transactivation whereas in MDA-MB-231, CAR and PPAR${\gamma}$ but not SXR tend to increase the transactivation of the reporter gene. These results indicate that the effects of ER cross-talk by the CAR, SXR, and PPAR${\gamma}$ , are different in breast cancer cells from hepatoma cells. In conclusion, the transcriptional regulation by estrogen can involve different cross-talk interaction between estrogen receptor and xenobiotic nuclear receptors depending on the estrogen target cells.