• Title/Summary/Keyword: fragmentation mechanism

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Effect of Sopung-tang on Glutamate-Induced Apoptosis in C6 Glial Cells (소풍탕(疎風湯)이 Glutamate에 의한 C6 Glial Cell의 Apoptosis에 미치는 영향)

  • Jeong, Seung-Won;Choi, Chul-Won;Kim, Bong-Sang;Moon, Byung-Soon
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.22 no.6
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    • pp.1423-1430
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    • 2008
  • The water extract of Sopung-tang(SPT) has been traditionally used for treatment of psycologic disease and brain damage in oriental medicine. However, little is known about the mechanism by which the water extract of SPT rescues cells from these disease. Therefore, this study was designed to investigate the effect of SPT on the glutamate-induced toxicity of rat C6 glial cells. SPT have protective effects in glutamate-induced toxicity, which was revealed as apoptosis characterized by chromatic condensation and fragmentation and the loss of mitochondrial membrane potential in C6 glial cells. Also, SPT have inhibited the active form of caspase-3 and PARP and significantly protected the apoptotic phenomena by glutamate toxicity in C6 glial cells. However, SPT significantly recovered the depletion of GSH and inhibited the generation of ROS by glutamate in C6 glial cells. In addition, both SPT and antioxidants such as GSH and NAC protected the glutamate-induced cytotoxicity in C6 glial cells, indicating that SPT possibly have antioxidative effect. Specially, SPT were showed transcriptional factor significantly increased the activation of NF-${\kappa}B$ using the analysis of NF-${\kappa}B$ luciferase reporter system in C6 glial cells. These NF-${\kappa}B$ activation protected cells from glutamate-induced toxicity to generate the heme oxygenase-1(HO-1). Taken together, we suggest that SPT have protective effects in glutamate-induced toxicity via a antioxidative mechanism.

Block based Smart Carving System for Forgery Analysis and Fragmented File Identification

  • Lee, Hanseong;Lee, Hyung-Woo
    • Journal of Internet Computing and Services
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    • v.21 no.3
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    • pp.93-102
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    • 2020
  • In order for data obtained through all stages of digital crime investigation to be recognized as evidence capability, it must satisfy legal / technical requirements. In this paper, we propose a mechanism and implement software to provide digital forensic evidence by automatically recovering files by scanning / inspecting the unallocated area inside the storage disk block without relying on information provided by the file system. The proposed technique checks / analyzes the RAW disk data of the system under analysis in 512-byte block units based on information on the storage format / file structure of various files stored on the disk without referring to the file system-related information provided by the operating system. The file carving process was implemented, and a smart carving mechanism was proposed to intelligently restore deleted or damaged files in the storage device. As a result, we have provided a block based smart carving method to intelligently identify fragmented and damaged files in storage efficiently for forgery analysis on digital forensic investigation.

Study on Apoptosis-Inducing Effects and Mechanism of Radix Paeoniae Alba Extract in DU145 Human Prostate Cancer Cell (백작약 추출물의 전립선 암세포 고사 유도 효과 및 기전 연구)

  • Kwon Kang Beom;Kim Eun Kyung;Kim Kyoung Jong;Kang Gil Seong;Kim Young Sun;Kim In Kyu;Kim In Seob;Kim In Soo;Lee Su Kyung;Seo Eun A;Ryu Do Gon
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.18 no.6
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    • pp.1617-1621
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    • 2004
  • The aim of this study was to investigate the apoptotic effect and its mechanism on Radix Paeoniae Alba Extract(RPAE) in DU145 human prostate cancer cell line. RPAE induced apoptosis in a dose-dependent manner in DU145 cells as confirmed by both discontinuous DNA fragmentation using Hoechst33342 staining and poly-(ADP-ribose) polymerase(PARP) cleavage, which are apoptotic signs. To clarify the mechanisms on RPAE-induced apoptosis, we examined the p50(NF-κB subunit), IκBα, PTEN and Par-4 protein expression using Western blotting. Treatment with RPAE resulted in the decrease of p50 expression by IκBα increase, which resulted in Par-4 increase and bcl-2 decrease in DU145 cells. These results suggest that apoptosis of DU145 cells by RPAE involved decreases of NF-κB activation and bcl-2 expression, increase of Par-4 protein expression.

Effects of Daechilgi-tang on Glutamate-induced Apoptosis in C6 Glial Cells (대칠기탕(大七氣湯)이 Glutamate에 의한 C6 Glial 세포의 Apoptosis에 미치는 영향)

  • Kim, Hye-Yoon;Ko, Seok-Jae;Bang, Chang-Ho;Shin, Sun-Ho;Lee, John Dong-Yeop;Lee, In
    • The Journal of Internal Korean Medicine
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    • v.31 no.4
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    • pp.693-705
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    • 2010
  • Objectives : The water extract of Daechilgi-tang(DCGT) has traditionally been used for treatment of qi stagnation(氣滯), which is considered to be one of the important causes of neuronal disease in oriental medicine. However, little is known about the mechanism by which DCGT protects neuronal cells from brain cell damages. Methods and Results : The author tested the mechanism of the cytoprotective effect of DCGT on glutamate -stimulated rat C6 glial cells. DCGT significantly protected C6 glial cells from glutamate in MTT assay. Pre-treatment of C6 glial cells with DCGT markedly inhibited the DNA fragmentation of C6 cells induced by glutamate. Glutamate increased the generation of reactive oxygen species(ROS) and intracellular calcium level in C6 glial cells. However, pre-treatment with DCGT markedly suppressed the increase of ROS generation and intracellular calcium accumulation induced by glutamate. Among apoptosis signaling mediators, DCGT markedly increased the expression level of Bcl2 in glutamate-treated cells. It also inhibited the cleavage of caspase-3 and PARP proteins by glutamate in C6 glial cells. Conclusions : These results suggest that DCGT protects brain cells from glutamate cytotoxicity through inhibition of ROS generation and activation of apoptosis signaling pathway as well as induction of the anti-oxidant system.

Enhancement of Arsenic Trioxide ($As_2O_3$)-Mediated Apoptosis Using Berberine in Human Neuroblastoma SH-SY5Y Cells

  • Kim, Dae-Won;Ahan, Song-Ho;Kim, Tae-Young
    • Journal of Korean Neurosurgical Society
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    • v.42 no.5
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    • pp.392-399
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    • 2007
  • Objective : Arsenic trioxide ($As_2O_3$) has been used as an anticancer agent in traditional Chinese medicine for thousand years and berberine is an isoquinoline alkaloid present that has indicated significant antimicrobial activity. We have examined the combined anticancer effects of $As_2O_3$ and berberine against the human neuroblastoma (HNB) SH-SY5Y cells in vitro, and to elucidate underlying molecular mechanism. Methods : HNB SH-SY5Y cells were treated with $2\;{\mu}M\;As_2O_3$ and $75\;{\mu}g/ml$ berberine, and their survival, cell death mechanism as well as synergistic cytotoxic effects were estimated by using MTT assay, DAPI staining, agarose gel electrophoresis, flow cytometric analysis, and western blot analysis. Results : The combined treatment of two drugs also markedly decreased cell viability. The cytotoxic effects of two drugs were revealed as apoptosis characterized by chromatin condensation, DNA fragmentation, and the loss of mitochondrial membrane potential. The apoptotic cytotoxicity was accompanied by activation of caspase-3 protease as well as decreased the expression of Bcl-2, Bid, and Bcl-x/L. In addition, the cells treated with combination of two drugs also showed significantly increased intracellular reactive oxygen species levels and lipid peroxidation compared to cells $As_2O_3$or berberine only. Conclusion : Combined treatment of $As_2O_3$ with berberine induced activation of apoptotic signaling pathways in HNB SH-SY5Y cells. These results suggest that the possibility of the combined treatment of two chemotherapeutic agents with low concentration improving cytotoxic effect for cancer cells with minimal side effects.

Alzheimer's Disease and Apoptosis

  • Kim, Young-Hoon;Kim, Hye-Sun;Park, Cheol-Hyoung;Jeong, Sung-Jin;Kim, Young-Kyung;Kim, Sun-Hee;Lee, Sang-Kyeng;Suh, Yoo-Hun;Kim, Sung Su
    • Korean Journal of Biological Psychiatry
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    • v.5 no.1
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    • pp.66-70
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    • 1998
  • Apoptosis is a form of cell death in which the cells shrink and exhibit nuclear chromatin condensation and DNA fragmentation, and yet maintain membrane integrity. Many lines of evidence have shown that brain neurons are vulnerable to degeneration by apoptosis. Also it has been suggested that apoptosis is one of the mechanism contributing neuronal loss in Alzheimer's disease(AD), since the conditions in the disease($A{\beta}$ peptide, oxidative stress, low energy metabolism) are the inducers that activate apoptosis. Indeed some neurons in vulnerable regions of the AD brain show DNA damage, chromatin condensation, and apoptic bodies. Consistently, mutations in AD causative genes(Amyloid precursor protein, Presenilin-1 and Presenilin- 2) increase $A{\beta}$ $peptide_{1-42}(A{\beta}_{1-42})$ and sensitize neuronal cell to apoposis. However, several lines of evidence have shown that the location of neuronal loss and $A{\beta}$ peptide deposition is not correlated in AD brain and transgenic mice brain over-expressing $A{\beta}_{1-42}$. Taken together, these data may indicated that $A{\beta}$ peptide(and other causative factors of AD) can interact with other cellular insults or risk factors to exacerbate pathological mechansim of AD through apoptosis. Thus, this review discusses possible role and mechanism of apoptosis in AD.

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Effects of Takrisodokyeum Water Extracts on LNCaP Prostate Cancer Cells

  • Park, Kwan-Woo;Kim, Song-Baeg;Choi, Chang-Min;Ryu, Do-Gon;Kwon, Kang-Beom
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.23 no.5
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    • pp.1154-1160
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    • 2009
  • Androgen receptors (AR) play a crucial role in the development and progression of prostate cancer. Many studies have suggested that prostate cancer cell proliferation is inhibited by AR downregulation, and it has been reported that Takrisodokyeum (TRSDY) induced apoptotic cell death and suppressed tumorigenesis in human leukemia cells. Therefore, this study was conducted to elucidate the mechanism by which TRSDY affects cell growth and AR expression in androgen-dependent prostate cancer cells (LNCaP cells). We investigated the proliferation and apoptosis of LNCaP cells using MTT and DNA fragmentation assays. In addition, we used western blot analysis to assess the effects of TRSDY on the expression of the AR target gene, prostate-specific antigen (PSA). Furthermore, the mechanism of AR downregulation by TRSDY was investigated using EMSA to analyze the binding activity of AR to androgen response elements (ARE). TRSDY significantly suppressed proliferation and induced apoptosis in LNCaP cells. In addition, TRSDY-induced apoptotic cell death was accompanied by activation of caspase-3 and cleavage of its substrate, poly(ADP-ribose) polymerase. TRSDY also inhibited the constitutively expressed- or 5a-dihydrotestosterone (DHT)-induced AR/PSA protein levels. However, these effects were mediated by inhibition of the binding of AR to ARE. TRSDY-mediated AR/PSA downregulation contributes to the inhibition of cell proliferation and the induction of apoptosis in LNCaP human prostate cancer cells. Our findings suggest that TRSDY may be used as a chemopreventive or chemotherapeutic agent for the treatment of prostate cancer.

G0/G1 Cell Cycle Arrest and Activation of Caspases in Honokiol-mediated Growth Inhibition of Human Gastric Cancer Cells

  • Kang, You-Jin;Chung, Hwa-Jin;Min, Hye-Young;Song, Ja-Young;Park, Hyen-Joo;Youn, Ui-Joung;Bae, Ki-Hwan;Kim, Yeong-Shik;Lee, Sang-Kook
    • Natural Product Sciences
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    • v.18 no.1
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    • pp.16-21
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    • 2012
  • Honokiol, a naturally occurring neolignan mainly found in Magnolia species, has been shown to have the anti-angiogenic, anti-invasive and cancer chemopreventive activities, but the molecular mechanism of actions has not been fully elucidated yet. In the present study, we investigated the effect of honokiol on the growth inhibitory activity in cultured SNU-638 human gastric cancer cells. We found that honokiol exerted potent antiproliferative activity against SNU-638 cells. Honokiol also arrested the cell cycle progression at the G0/G1 phase and induced the apoptotic cell death in a concentration-dependent manner. The cell cycle arrest was well correlated with the downregulation of Rb, cyclin D1, cyclin A, cyclin E, and CDK4 expression, and the induction of cyclin-dependent kinase inhibitor p27. The increase of sub-G1 peak by honokiol was closely related to the induction of apoptosis, which was evidenced by the induction of DNA fragmentation, the cleavage of poly(ADPribose) polymerase, and the sequential activation of caspase cascade. These findings suggest the cell cycle arrest and induction of apoptosis might be one possible mechanism of actions for the anti-proliferative activity of honokiol in human gastric cancer cell.

Effects of Samul-tang on Nitric Oxide Induced-cytotoxicity in C6 Glial Cell (Nitric Oxide에 의해 유발된 C6 glial 세포독성(細胞毒性)에 대한 사물탕(四物湯)의 방어효과(防禦效果))

  • Kim, Do-Hwan;Kim, Seung-Mo;Cho, Han-Gook;Cha, Yong-Seok;Heo, Yun;Cho, Kwang-Ho;Moon, Byung-Soon
    • The Journal of Internal Korean Medicine
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    • v.21 no.4
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    • pp.535-542
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    • 2000
  • The water extracts of Samul-tang(SMT) has been used for treatment of ischemic brain damage in Oriental traditional medicine. However, little is known about the mechanism by which the water extracts of SMT rescues brain cells from ischemic damages. To elucidate the protective mechanism on ischemic induced cytotoxicity, I investigate the regulation of LPS and PMA induced iNOS expression in C6 glial cells. LPS and PMA treatment for 72 h in C6 glial cells markedly induce nitric oxide(NO), but treatment of the cells with the water extracts of SMT decrease. dose dependently nitrite formation. In addition, LPS and PMA treatment for 72 h induce severe cell death and LDH release in C6 glial cells. However treatment of the cells with the water extracts of SMT dose not induce significant changes compare to control cells. Furthermore, the protective effects of the water extracts of SMT is mimicked by treatment of $N^{G}MMA$, a specific inhibitor of NOS. LPS and PMA induced iNOS activation in C6 glial cells cause chromosomal condensation and fragmentation of nuclei by caspase activation. The treatment of the cells with the water extracts of SMT may suppress apoptosis via caspase inhibition by regulation of iNOS expression. Taken together, I suggest that the protective effects of the water extracts of SMT against ischemic brain damages may be mediated by regulation of iNOS during ischemic condition.

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Ethanol-eluted Extract of Rhus verniciflua Stokes Inhibits Cell Growth and Induces Apoptosis in Human Lymphoma Cells

  • Lee, Jeong-Chae;Kim, Ju;Jang, Yong-Suk
    • BMB Reports
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    • v.36 no.4
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    • pp.337-343
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    • 2003
  • Rhus verniciflua Stokes (RVS) has been used as a traditional herbal medicine. Several earlier studies indicated that an ethanol extract of RVS has both anti-oxidant and anti-tumor properties, although the mechanism for the activity remains to be elucidated. In this report, we prepared a highly purified ethanol extract from RVS, named REEE-1 ($\underline{R}$hus $\underline{e}$thanol $\underline{e}$luted $\underline{e}$xtract-1), and investigated the mechanism involved in its growth-inhibitory effect on the human B and T lymphoma cell lines, BJAB and Jurkat, respectively. Results from tritium uptake proliferation assays showed that the proliferative capacities of both BJAB and Jurkat cells were strongly suppressed in the presence of REEE-1. This was further confirmed through trypan blue exclusion experiments that revealed a dose-dependent decrease in viable cell numbers after REEE-1 treatment. REEE-1-mediated suppression of cell growth was verified to be apoptotic, based on the increase in DNA fragmentation, low fluorescence intensity in nuclei after propidium iodide staining, and the appearance of DNA laddering. In particular, REEE-1 exerted its anti-oxidant activity through the inhibition of hydroxyl radical-mediated degradation by iron ion chelation rather than direct scavenging of hydroxyl radicals. Furthermore, REEE-1 was revealed to be a potential scavenger of superoxide anions. Collectively, our findings suggest that REEE-1 is a natural anti-oxidant that could be used as a cancer chemo-preventive and therapeutic agent.