• 대한의생명과학회지
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• 제20권2호
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• pp.56-61
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• 2014

This study attempted to confirm the antioxidative potential of luteolin against tert-butyl hydroperoxide (t-BHP) induced oxidative damage and to investigate its molecular mechanism related to glutathione (GSH)-dependent enzymes in HepG2 cells. Treatment with luteolin resulted in attenuation of t-BHP induced generation of reactive oxygen species (ROS) and oxidative stress-mediated cell death. In addition, accelerated expression of GSH-dependent antioxidative enzymes, glutathione peroxidase (GPx) and glutathione reductase (GR), and heme oxygenase (HO)-1, as well as strengthened GSH content was induced by treatment with luteolin, which was in accordance with increased nuclear translocation of nuclear factor-erythroid 2 p45-related factor 2 (Nrf2), a transcription factor for phase 2 enzymes, in a dose-dependent manner. These results suggest that the cytoprotective potential of luteolin against oxidative damage can be attributed to fortified GSH-mediated antioxidative pathway and HO-1 expression through regulation of Nrf2 in HepG2 cells.

• Tuberculosis and Respiratory Diseases
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• 제71권2호
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• pp.88-96
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• 2011

Background: It is known that cigarette smoke (CS) causes cell death. Apoptotic cell death is involved in the pathogenesis of CS-related lung diseases. Some members of the protein kinase C (PKC) family have roles in cigarette smoke extract (CSE)-induced apoptosis. This study was conducted to investigate the role of PKC epsilon in CSE-induced apoptosis in human lung fibroblast cell line, MRC-5. Methods: Lactate dehydrogenase release was measured using a cytotoxicity detection kit. The MTT assay was used to measure cell viability. Western immunoblot, Hoechst 33342 staining and flow cytometry were used to demonstrate the effect of $PKC{\varepsilon}$. Caspase-3 and caspase-8 activities were determined using a colorimetric assay. To examine $PKC{\varepsilon}$ activation, Western blotting was performed using both fractions of membrane and cytosol. Results: We showed that CSE activated $PKC{\varepsilon}$ by demonstrating increased expression of $PKC{\varepsilon}$ in the plasma membrane fraction. Pre-treatment of $PKC{\varepsilon}$ peptide inhibitor attenuated CSE-induced apoptotic cell death, as demonstrated by the MTT assay (13.03% of control, 85.66% of CSE-treatment, and 53.73% of $PKC{\varepsilon}$ peptide inhibitor-pre-treatment, respectively), Hoechst 33342 staining, and flow cytometry (85.64% of CSE-treatment, 53.73% of $PKC{\varepsilon}$ peptide inhibitor-pre-treatment). Pre-treatment of $PKC{\varepsilon}$ peptide inhibitor reduced caspase-3 expression and attenuated caspase-3, caspase-8 activity compared with CSE treatment alone. Conclusion: $PKC{\varepsilon}$ seem to have pro-apoptotic function and exerts its function through the extrinsic apoptotic pathway in CSE-exposed MRC-5 cells. This study suggests that $PKC{\varepsilon}$ inhibition may be a therapeutic strategy in CS-related lung disease such as chronic obstructive pulmonary disease.

• Journal of Preventive Medicine and Public Health
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• 제51권4호
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• pp.205-212
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• 2018

Objectives: The main purpose of this study was to quantify the risk of mortality linked to various regimens of hypertonic peritoneal dialysis (PD) solution. Methods: A retrospective cohort study of patients using home-based PD was carried out. The prescribed regimen of glucose-based PD solution for all patients, determined on the basis of their individual conditions, was extracted from their medical chart records. The primary outcome was death. The treatment regimens were categorized into 3 groups according to the type of PD solution used: original PD (1.5% glucose), shuffle PD (1.5 and 2.5% glucose), and serialized PD (2.5 and 4.5% glucose). Multivariate analysis (using the Weibull model) was applied to comprehensively examine survival probabilities related to the explanatory variable, while adjusting for other potential confounders. Results: Of 300 consecutive patients, 38% died over a median follow-up time of 30 months (interquartile range: 15-46 months). Multivariate analysis showed that a treatment regimen with continued higher-strength PD solution (serialized PD) resulted in a lower survival rate than when the conventional strength solution was used (adjusted hazard ratio, 2.6; 95% confidence interval, 1.6 to 4.6, p<0.01). Five interrelated risk factors (age, length of time on PD, hemoglobin levels, albumin levels, and oliguria) were significant predictors contributing to the outcome. Conclusions: Frequent exposure to high levels of glucose PD solution significantly contributed to a 2-fold higher rate of death, especially when hypertonic glucose was prescribed continuously.

• BMB Reports
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• 제55권3호
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• pp.148-153
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• 2022

Etoposide is a chemotherapeutic medication used to treat various types of cancer, including breast cancer. It is established that pulsed electromagnetic field (PEMF) therapy can enhance the effects of anti-cancer chemotherapeutic agents. In this study, we investigated whether PEMFs influence the anti-cancer effects of etoposide in MCF-7 cells and determined the signal pathways affected by PEMFs. We observed that co-treatment with etoposide and PEMFs led to a decrease in viable cells compared with cells solely treated with etoposide. PEMFs elevated the etoposide-induced PARP cleavage and caspase-7/9 activation and enhanced the etoposide-induced down-regulation of survivin and up-regulation of Bax. PEMF also increased the etoposide-induced activation of DNA damage-related molecules. In addition, the reactive oxygen species (ROS) level was slightly elevated during etoposide treatment and significantly increased during co-treatment with etoposide and PEMF. Moreover, treatment with ROS scavenger restored the PEMF-induced decrease in cell viability in etoposide-treated MCF-7 cells. These results combined indicate that PEMFs enhance etoposide-induced cell death by increasing ROS induction-DNA damage-caspase-dependent apoptosis.

• 한방재활의학과학회지
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• 제18권2호
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• pp.33-43
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• 2008

Objectives : Sunghyangjungki-san(Xingxiangzhengqi-san) is a herb decoction prescribed frequently for stroke patients. The present study investigated neuroprotective effects of Sunghyangjungki-san(Xingxiangzhengqi-san) against the ischemic damage of the rat brain. Neuronal cell death under the cerebral ischemia is distinguished with the delayed cell death through apoptosis. Consequently, the effects of Sunghyangjungki-san(Xingxiangzhengqi-san) was evaluated with Bax and Bcl-2 expressions as apoptosis related factors in the brain tissues. Methods : The ischemic damage was induced by the middle cerebral artery occlusion(MCAO) method in Sprague-Dawley rats. Water extract of Sunghyangjungki-san(Xingxiangzhengqi-san) was treated for 5 days after the MCAO. Neurological scores and infarct size with TTC were measured. Bax and Bcl-2 expressions in the brain tissues were observed with immunohistochemistry. Results : Sunghyangjungki-san(Xingxiangzhengqi-san) treatment improved neurological score significantly at 5 days after the MCAO. Sunghyangjungki-san(Xingxiangzhengqi-san) treatment decreased infarct size by the MCAO, but it was not significant statistically. Sunghyangjungki-san(Xingxiangzhengqi-san) treatment attenuated Bax positive neurons significantly in the cerebral penumbra and the caudate putamen. Bcl-2 positive neurons were increased, but not significant. Sunghyangjungki-san(Xingxiangzhengqi-san) treatment increased Bcl-2/Bax expression ratios significantly in the cerebral penumbra and the caudate putamen. Conclusions : These results suggest that Sunghyangjungki-san(Xingxiangzhengqi-san) has a neuroprotective effect on the stroke with modulation of apoptosis related factors.

• Animal cells and systems
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• 제15권1호
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• pp.9-17
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• 2011

Colorectal cancer is the third leading cause of cancer-related death in Western countries. Chemotherapeutic agents with different mechanisms of action have shown an increase in cure rates. In the present study, we investigated the effect of a combination of low concentration of paclitaxel (taxol, 5 nM) and topoisomerase 1 inhibitor camptothecin (CPT) on HCT116 colon cancer cells. Although the viability of cells treated with taxol alone was similar to that of control cells, sequential treatment with taxol and CPT exhibited high cytotoxicity. However, the opposite sequence of treatment did not exert cytotoxic effects on HCT116 cells. This enhanced cytotoxicity of the sequential combination therapy was the result of mitotic arrest, which increased the level of $p21^{Cip1/WAF1}$ through the p38 mitogen-activated protein kinase (MAPK) pathway. Knockdown by $p21^{Cip1/WAF1}$ siRNA or treatment with a p38 inhibitor reduced the viability of cells sequentially exposed to taxol and CPT. Taken together, a low taxol concentration in combination with CPT induced mitotic arrest in HCT116 cells, leading to synergistic cell death through enhanced expression of $p21^{Cip1/WAF1}$ and p38 MAPK pathway. Therefore, taxol could playa role as a sensitizer of CPT in colon cancer cells.

• Korean Circulation Journal
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• 제48권12호
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• pp.1135-1144
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• 2018

Background and Objectives: Mitochondria play a key role in the pathophysiology of heart failure and mitochondrial permeability transition pore (MPTP) play a critical role in cell death and a critical target for cardioprotection. The aim of this study was to evaluate the protective effects of cyclosporine A (CsA), one of MPTP blockers, and morphological changes of mitochondria and MPTP related proteins in monocrotaline (MCT) induced pulmonary arterial hypertension (PAH). Methods: Eight weeks old Sprague-Dawley rats were randomized to control, MCT (60 mg/kg) and MCT plus CsA (10 mg/kg/day) treatment groups. Four weeks later, right ventricular hypertrophy (RVH) and morphological changes of right ventricle (RV) were done. Western blot and reverse transcription polymerase chain reaction (RT-PCR) for MPTP related protein were performed. Results: In electron microscopy, CsA treatment prevented MCT-induced mitochondrial disruption of RV. RVH was significantly increased in MCT group compared to that of the controls but RVH was more increased with CsA treatment. Thickened medial wall thickness of pulmonary arteriole in PAH was not changed after CsA treatment. In western blot, caspase-3 was significantly increased in MCT group, and was attenuated in CsA treatment. There were no significant differences in voltage-dependent anion channel, adenine nucleotide translocator 1 and cyclophilin D expression in western blot and RT-PCR between the 3 groups. Conclusions: CsA reduces MCT induced RV mitochondrial damage. Although, MPTP blocking does not reverse pulmonary pathology, it may reduce RV dysfunction in PAH. The results suggest that it could serve as an adjunctive therapy to PAH treatment.

• 기본간호학회지
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• 제26권3호
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• pp.197-209
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• 2019

Purpose: This study was done to examine good death awareness, attitudes toward advance directives (ADs), and preference for care near the end-of-life (PCEOL) of hospitalized elders in long-term care hospitals. Relevant characteristics were investigated as well as correlation of the variables. Methods: This descriptive research study involved 161 hospitalized elderly patients in long-term care hospitals. A self-report questionnaire was used to measure Good Death Scale, ADs Survey, PCEOL Scale, and general characteristics. Collected data were analyzed using descriptive statistics, t-test, ANOVA, and Pearson correlation with SPSS/WIN 23.0. Results: In terms of good death awareness, a significant difference was observed; in according to age (F=3.35, p=.037), payer of treatment costs (F=3.98, p=.021), mobility (F=3.97, p=.021), heard discussion about ADs (t=-3.89, p<.001), and willing to complete ADs (t=2.12, p=.036). As far as attitudes toward ADs, the participants presented significant difference depending on religion (t=2.38, p=.018), average monthly income (F=3.91, p=.022), duration of hospital admission (F=5.33, p=.006), person to discuss ADs (t=-2.76, p=.006). On PCEOL, there was a significant difference, depending on religion (t=-3.59, p<.001) and perceived health status (F=3.93, p=.022). Finally, as for how the variables were related to each other, good death awareness and attitudes toward ADs had a weak positive correlation with PCEOL. Conclusion: To help seniors staying in nursing homes face a good death and enjoy autonomy, there should be educational and support systems that reflect each individual's sociodemographic characteristics so that the seniors can choose what kind of care they want to receive near the end-of-life.

• IMMUNE NETWORK
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• 제16권1호
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• pp.75-84
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• 2016

Cancer is one of the leading causes of morbidity and mortality worldwide; therefore there is a need to discover new therapeutic modules with improved efficacy and safety. Immune-(cell) therapy is a promising therapeutic strategy for the treatment of intractable cancers. The effectiveness of certain chemotherapeutics in inducing immunogenic tumor cell death thus promoting cancer eradication has been reported. Ginsenoside Rg3 is a ginseng saponin that has antitumor and immunomodulatory activity. In this study, we treated tumor cells with Rg3 to verify the significance of inducing immunogenic tumor cell death in antitumor therapy, especially in DC-based immunotherapy. Rg3 killed the both immunogenic (B16F10 melanoma cells) and non-immunogenic (LLC: Lewis Lung Carcinoma cells) tumor cells by inducing apoptosis. Surface expression of immunogenic death markers including calreticulin and heat shock proteins and the transcription of relevant genes were increased in the Rg3-dying tumor. Increased calreticulin expression was directly related to the uptake of dying tumor cells by dendritic cells (DCs): the proportion of CRT⁺CD11c⁺cells was increased in the Rg3-treated group. Interestingly, tumor cells dying by immunogenic cell death secreted IFN-γ, an effector molecule for antitumor activity in T cells. Along with the Rg3-induced suppression of pro-angiogenic (TNF-α) and immunosuppressive cytokine (TGF-β) secretion, IFN-γ production from the Rg3-treated tumor cells may also indicate Rg3 as an effective anticancer immunotherapeutic strategy. The data clearly suggests that Rg3-induced immunogenic tumor cell death due its cytotoxic effect and its ability to induce DC function. This indicates that Rg3 may be an effective immunotherapeutic strategy.

• 한국식품영양학회지
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• 제21권4호
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• pp.416-424
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• 2008

In an effort to elucidate the differential actions of blueberry(BB) in both normal and cancer cells, we utilized human breast cell lines to assess the accumulation of radical oxygen species(ROS) and ROS-associated apoptosis in both human normal breast epithelial(MCF10A) and breast cancer(MCF7) cells. BB extract was added to the cultures at a final concentration of $20{\mu}g/m{\ell}$ for 0(control), 6, 12, and 24 hr intervals. The MCF10A cells evidenced no marked ROS accumulation in the presence of BB, whereas the MCF7 cells evidenced clear ROS accumulation upon BB treatment from 12 hours forward. The number of dying or dead cells did not increase in the BB-treated MCF10A cell groups, whereas that number increased profoundly from 12 hr forward. Furthermore, the expression levels of certain stress-related, and pro- and antiapoptotic gene products evidenced differential responses to BB treatment between the MCF10A and MCF7 cell groups. These results indicate that the components of BB extract differentiate cancer cells by not preventing ROS accumulation within cells and by inducing ROS-associated cell death in cancer cells. However, no marked ROS accumulation or induction of cell death was noted in the normal breast epithelial cells. The fact that BB extract exerted a differential effect on cancer cells opens further directions of research regarding the specific components that exert the differential BB-mediated effects in the selective prevention of normal cells and therapy for cancer tissues in the physiological body.