• Title/Summary/Keyword: Potential-induced degradation

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Hepatoprotective effect of Ikwiseungyang-tang via Nrf2 activation (Nrf2 활성화를 통한 익위승양탕(益胃升陽湯)의 간세포 보호 효과)

  • Jin, Hyo Jeong;Park, Sang Mi;Kim, Eun Ok;Kim, Sang Chan
    • Herbal Formula Science
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    • v.29 no.4
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    • pp.167-179
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    • 2021
  • Objectives : Oxidative stress is a important cause of liver disease, and regulation of oxidative stress is essential to maintain the normal metabolic function of the liver. Until a recent date, there has been no studies on the hepatoprotective effect of Ikwiseungyang-tang (IWSYT). Therefore, this study aims to demonstrate the hepatoprotective effect of IWSYT and its related molecular mechanisms on arachidonic acid (AA) + iron induced oxidative stress model in HepG2 cells. Methods : To determine the cytoprotective effect of IWSYT against AA + iron-induced oxidative stress, cell viability, apoptosis-related proteins, intracellular reactive oxygen species (ROS), GSH, and mitochondrial membrane potential (MMP) were measured. Nuclear factor erythroid 2-related factor 2 (Nrf2) activation was analyzed by immunoblot analysis. In addition, Nrf2 transcription activation through ARE binding was measured by reporter gene assays, and the expression of the Nrf2 target antioxidant genes were confirmed by immunoblot analysis. Results : IWSYT increased cell viability from cell death induced by AA + Iron, and inhibited apoptosis by regulating apoptosis-related proteins. Furthermore, IWSYT protected cells by inhibiting intracellular ROS production, GSH depletion, and MMP degradation. Nrf2 activation was increased by IWSYT, and Nrf2 target genes were activated by IWSYT too. Conclusions : These results suggest that IWSYT can protect hepatocytes from oxidative stress through Nrf2 activation and can be potentially applied in the prevention and treatment of liver damage.

Effect of Co-administration of Aconiti Lateralis Preparata Radix and Cinnamomi Cortex on Osteoclast Differentiation (부자와 육계 병용투여 시 파골세포 분화 억제에 미치는 영향)

  • Jung, Gi-Eun;Kim, Jung Young;Kim, Ji-Hoon;Han, Sang-Yong;Kim, Yun-Kyung
    • The Korea Journal of Herbology
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    • v.29 no.2
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    • pp.61-67
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    • 2014
  • Objectives : Aconiti Lateralis Preparata Radix (Aconitum Carmichaeli, AC) and Cinnamomi Cortex (Cinnamomi Cortex, CC) have been treated to elderly for kidney yang enhancement in Korean traditional medicine. In this study, the effects of water extract of AC and CC on RANKL (Receptor Activator for Nuclear Factor ${\kappa}B$ Ligand)-induced osteoclast differentiation were evaluated in culture system. Methods : MTT assay was used to evaluate the potential cytotoxicity of AC and CC extracts in bone macrophage marrows (BMMs) stimulated with M-CSF. TRAP (tartrate-resistant acid phosphatase) staining and TRAP activity were performed to know the inhibitory effect on osteoclast differentiation. The protein expression levels of nuclear factors such as activated T cell(NFAT)c1, c-Fos, MAPKs and ${\beta}$-actin in cell lysates treated with AC and CC extracts were analysed by western blotting. Results : AC, CC extracts and their co-administration inhibited significantly RANKL-induced osteoclast differentiation in BMMs in a dose dependent manner without toxicity. Each AC and CC extracts inhibited the phosphorylation of p38. Also, AC and CC extracts, respectively, inhibited the protein expression of c-Fos and NFATc1 more than Co-administration of AC and CC even if all treatments did. It was observed that RANKL-induced degradation of I-${\kappa}B$ is significantly suppressed by all treatments. Conclusions : Taken together, It was concluded that AC and CC have beneficial effect on osteoporosis by inhibition of osteoclast differentiation. Thus, Atractylodis AC and CC could be a treatment option for osteoporosis.

Inhibitory Effect of Sageretia theezans against the Production of Pro-Inflammatory Mediators through the Inhibition of NF-κB and MAPK, and Activation of Nrf2/HO-1 Signaling Pathways in LPS-Stimulated RAW264.7 cells

  • Kim, Ha Na;Park, Su Bin;Kim, Jeong Dong;Jeong, Hyung Jin;Jeong, Jin Boo
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2018.10a
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    • pp.98-98
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    • 2018
  • In this study, we evaluated the anti-inflammatory effect of extracts of leaves (ST-L) and branches (ST-B) from Sageretia theezans in LPS-stimulated RAW264.7 cells. ST-L and ST-B significantly inhibited the production of the pro-inflammatory mediators such as NO, iNOS, COX-2, $IL-1{\beta}$ and IL-6 in LPS-stimulated RAW264.7 cells. ST-L and ST-B blocked LPS-induced degradation of $I{\kappa}B-{\alpha}$ and nuclear accumulation of p65, which resulted to the inhibition of $NF-{\kappa}B$ activation in RAW264.7 cells. ST-L and ST-B also attenuated the phosphorylation of ERK1/2, p38 and JNK in LPS-stimulated RAW264.7 cells. In addition, ST-L and ST-B increased HO-1 expression in RAW264.7 cells, and the inhibition of HO-1 by ZnPP reduced the inhibitory effect of ST-L and ST-B against LPS-induced NO production in RAW264.7 cells. Inhibition of p38 activation and ROS elimination attenuated HO-1 expression by ST-L and ST-B, and ROS elimination inhibited p38 activation induced by ST-L and ST-B. ST-L and ST-B dramatically induced nuclear accumulation of Nrf2, but this was significantly reversed by the inhibition of p38 activation and ROS elimination. Collectively, our results suggest that ST-L and ST-B exerts potential anti-inflammatory activity by suppressing $NF-{\kappa}B$ and MAPK signaling activation, and activating HO-1 expression through the nuclear accumulation of Nrf2 via ROS-dependent p38 activation. These findings suggest that ST-L and ST-B may have great potential for the development of anti-inflammatory drug to treat acute and chronic inflammatory disorders.

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Induction of G1 Phase Cell Cycle Arrest and Apoptotic Cell Death by 5-Fluorouracil in Ewing′s Sarcoma CHP-100 Cells (CHP-100 Ewing′s 육종세포에서 5-fluorouracil에 의한 G1 arrest 유도 및 apoptosis 유발에 관한 연구)

  • Kim, Sung Ok;Choi, Yung Hyun
    • Journal of Life Science
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    • v.26 no.9
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    • pp.1015-1021
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    • 2016
  • 5-fluorouracil (5-FU), a pyrimidine analog, is a widely used anticancer drug, which works through irreversible inhibition of thymidylate synthase. In the present study, it was investigated the anti-proliferative effects and molecular mechanisms of 5-FU using Ewing's Sarcoma CHP-100 Cells. The present data indicated that treatment of 5-FU to CHP-100 cells induced a G1 phase arrest of the cell cycle in a time-dependent manner. 5-FU-induced G1 arrest was correlated with the accumulation of the hypophosphorylated form of the retinoblastoma protein (pRB) and association of pRB with the transcription factors E2F-1 and E2F-4. Although 5-FU treatment did affect the levels of cyclin-dependent kinases, the levels of cyclin A and B were markedly down-regulated as compared with the untreated control group. In addition, 5-FU-induced G1 arrest of CHP-100 cells was also associated with the induction of apoptosis, as determined by apoptotic cell morphologies, degradation of poly(ADP-ribose) polymerase and Annexin V staining. Furthermore, 5-FU induced the loss of mitochondrial membrane potential with up-regulated pro-apoptotic Bax expression, down-regulated anti-apoptotic Bcl-2 expression and cytochrome c release from mitochondria to cytosol. Collectively, the data suggest that 5-FU is effective in inducing cell growth reduction and apoptosis, in part, by reducing phosphorylation of pRB and activating mitochondrial dysfunction in CHP-100 cells.

Rg3-enriched red ginseng extracts enhance apoptosis in CoCl2-stimulated breast cancer cells by suppressing autophagy

  • Yun-Jeong Jeong;Mi-Hee Yu;Yuna Cho;Min-Young Jo;Kwon-Ho Song;Yung Hyun Choi;Taeg Kyu Kwon;Jong-Young Kwak;Young-Chae Chang
    • Journal of Ginseng Research
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    • v.48 no.1
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    • pp.31-39
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    • 2024
  • Background: Ginsenoside Rg3, a primary bioactive component of red ginseng, has anti-cancer effects. However, the effects of Rg3-enriched ginseng extract (Rg3RGE) on apoptosis and autophagy in breast cancer have not yet been investigated. In the present study, we explored the anti-tumor effects of Rg3RGE on breast cancer cells stimulated CoCl2, a mimetic of the chronic hypoxic response, and determined the operative mechanisms of action. Methods: The inhibitory mechanisms of Rg3RGE on breast cancer cells, such as apoptosis, autophagy and ROS levels, were detected both in vitro. To determine the anti-cancer effects of Rg3RGE in vivo, the cancer xenograft model was used. Results: Rg3RGE suppressed CoCl2-induced spheroid formation and cell viability in 3D culture of breast cancer cells. Rg3RGE promoted apoptosis by increasing cleaved caspase 3 and cleaved PARP and decreasing Bcl2 under the hypoxia mimetic conditions. Further, we identified that Rg3RGE promoted apoptosis by inhibiting lysosomal degradation of autophagosome contents in CoCl2-induced autophagy. We further identified that Rg3RGE-induced apoptotic cell death and autophagy inhibition was mediated by increased intracellular ROS levels. Similarly, in the in vivo xenograft model, Rg3RGE induced apoptosis and inhibited cell proliferation and autophagy. Conclusion: Rg3RGE-stimulated ROS production promotes apoptosis and inhibits protective autophagy under hypoxic conditions. Autophagosome accumulation is critical to the apoptotic effects of Rg3RGE. The in vivo findings also demonstrate that Rg3RGE inhibits breast cancer cell growth, suggesting that Rg3RGE has potential as potential as a putative breast cancer therapeutic.

Root Bark of Morus alba L. and Its Bioactive Ingredient, Ursolic Acid, Suppress the Proliferation of Multiple Myeloma Cells by Inhibiting Wnt/β-Catenin Pathway

  • Song, Geu Rim;Choi, Yoon Jung;Park, Soo Jin;Shin, Subeen;Lee, Giseong;Choi, Hui Ji;Lee, Do Yup;Song, Gyu-Yong;Oh, Sangtaek
    • Journal of Microbiology and Biotechnology
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    • v.31 no.11
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    • pp.1559-1567
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    • 2021
  • The root bark of Morus alba L. has cytotoxic activity against several types of cancer cells. However, little is known about its chemopreventive mechanisms and bioactive metabolites. In this study, we showed that M. alba L. root bark extracts (MRBE) suppressed β-catenin response transcription (CRT), which is aberrantly activated in various cancers, by promoting the degradation of β-catenin. In addition, MRBE repressed the expression of the β-catenin/T-cell factor (TCF)-dependent genes, c-myc and cyclin D1, thus inhibiting the proliferation of RPMI-8226 multiple myeloma (MM) cells. MRBE induced apoptosis in MM cells, as evidenced by the increase in the population of annexin VFITC-positive cells and caspase-3/7 activity. We identified ursolic acid in MRBE through LC/mass spectrum (MS) and observed that it also decreased intracellular β-catenin, c-myc, and cyclin D1 levels. Furthermore, it suppressed the proliferation of RPMI-8226 cells by stimulating cell cycle arrest and apoptosis. These findings suggest that MRBE and its active ingredient, ursolic acid, exert antiproliferative activity by promoting the degradation of β-catenin and may have significant chemopreventive potential against MM.

Synthesis and Characteristics of Pd/r-TiO2 Nanotube Arrays Hetrojunction Photocatalyst (Pd/r-TiO2 나노튜브 이종결합 광촉매의 합성과 특성)

  • Lee, Jong-Ho;Lee, Young-Ki;Kim, Young-Jig;Jang, Kyung-Wook;Oh, Han-Jun
    • Korean Journal of Materials Research
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    • v.32 no.1
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    • pp.14-22
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    • 2022
  • To improve light absorption ability in the visible light region and the efficiency of the charge transfer reaction, Pd nanoparticles decorated with reduced TiO2 nanotube photocatalyst were synthesized. The reduced TiO2 nanotube photocatalyst was fabricated by anodic oxidation of Ti plate, followed by an electrochemical reduction process using applied cathodic potential. For TiO2 photocatalyst electrochemically reduced using an applied voltage of -1.3 V for 10 min, 38% of Ti4+ ions on TiO2 surface were converted to Ti3+ ion. The formation of Ti3+ species leads to the decrease in the band gap energy, resulting in an increase in the light absorption ability in the visible range. To obtain better photocatalytic efficiency, Pd nanoparticles were decorated through photoreduction process on the surface of reduced TiO2 nanotube photocatalyst (r10-TNT). The Pd nanoparticles decorated with reduced TiO2 nanotube photocatalyst exhibited enhanced photocurrent response, and high efficiency and rate constant for aniline blue degradation; these were ascribed to the synergistic effect of the new electronic state of the TiO2 band gap energy induced by formation of Ti3+ species on TiO2, and by improvement of the charge transfer reaction.

N-recognins UBR1 and UBR2 as central ER stress sensors in mammals

  • Ly Thi Huong Luu Le;Seoyoung Park;Jung Hoon Lee;Yun Kyung Kim;Min Jae Lee
    • Molecules and Cells
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    • v.47 no.1
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    • pp.100001.1-100001.8
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    • 2024
  • In eukaryotes, a primary protein quality control (PQC) process involves the destruction of conformationally misfolded proteins through the ubiquitin-proteasome system. Because approximately one-third of eukaryotic proteomes fold and assemble within the endoplasmic reticulum (ER) before being sent to their destinations, the ER plays a crucial role in PQC. The specific functions and biochemical roles of several E3 ubiquitin ligases involved in ER-associated degradation in mammals, on the other hand, are mainly unknown. We identified 2 E3 ligases, ubiquitin protein ligase E3 component N-recognin 1 (UBR1) and ubiquitin protein ligase E3 component N-recognin 2 (UBR2), which are the key N-recognins in the N-degron pathway and participate in the ER stress response in mammalian cells by modulating their stability. Cells lacking UBR1 and UBR2 are hypersensitive to ER stress-induced apoptosis. Under normal circumstances, these proteins are polyubiquitinated through Lys48-specific linkages and are then degraded by the 26S proteasome. In contrast, when cells are subjected to ER stress, UBR1 and UBR2 exhibit greater stability, potentially as a cellular adaptive response to stressful conditions. Although the precise mechanisms underlying these findings require further investigation, our findings show that cytoplasmic UBR1 and UBR2 have anti-ER stress activities and contribute to global PQC in mammals. These data also reveal an additional level of complexity within the mammalian ER-associated degradation system, implicating potential involvement of the N-degron pathway.

Synthetic Chenodeoxycholic Acid Derivative HS-1200-Induced Apoptosis of Human Oral Squamous Carcinoma Cells (합성 Chenodeoxycholic Acid 유도체 HS-1200이 유도한 사람구강 편평상피암종세포 세포자멸사 연구)

  • Kim, In-Ryoung;Sohn, Hyeon-Jin;Kim, Gyoo-Cheon;Kwak, Hyun-Ho;Park, Bong-Soo;Choi, Won-Chul;Ko, Myung-Yun;Ahn, Yong-Woo
    • Journal of Oral Medicine and Pain
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    • v.32 no.3
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    • pp.251-261
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    • 2007
  • Bile acids and synthetic its derivatives induced apoptosis in various kinds of cancer cells and anticancer effects. Previous studies have been reported that the synthetic chenodeoxycholic acid (CDCA) derivatives showed apoptosis inducing activity on various cancer cells in vitro. It wasn't discovered those materials have apoptosis induced effects on YD9 human oral squamous carcinoma cells. The present study was done to examine the synthetic bile acid derivatives(HS-1199, HS-1200) induced apoptosis on YD9 cells and such these apoptosis events. We administered them in culture to YD9 cells. Tested YD9 cells showed several lines of apoptotic manifestation such as activation of caspase-3, degradation of DFF, production of poly (ADP-ribose) polymerase(PARP) cleavage(HS-1200 only), DNA degradation(HS-1200 only), nuclear condensation, inhibition of proteasome activity, reduction of mitochondrial membrane potential(HS-1200 only) and the release of cytochrome c and AIF to cytosol. Between two synthetic CDCA derivatives, HS-1200 showed stronger apoptosis-inducing effect than HS-1199. Therefore HS-1200 was demonstrated to have the most efficient antitumor effect. Taken collectively, we demonstrated that a synthetic CDCA derivative HS-1200 induced caspases-dependent apoptosis via mitochondrial pathway in human oral sqauamous carcinoma cells in vitro. Our data therefore provide the possibility that HS-1200 could be considered as a novel therapeutic strategy for human orall squamous carcinoma from its poweful apoptosis-inducing activity.

Antioxidant and Anti-hyperglycemic Activity of Polysaccharide Isolated from Dendrobium chrysotoxum Lindl

  • Zhao, Yaping;Son, Young-Ok;Kim, So-Soon;Jang, Yong-Suk;Lee, Jeong-Chae
    • BMB Reports
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    • v.40 no.5
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    • pp.670-677
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    • 2007
  • Although polysaccharide is believed to play an important role in the medicinal effect of Dendrobium chrysotoxum Lindl (DCL), its role as an antioxidant and in anti-hyperglycemic induction was not reported. In this study, polysaccharide with molecular weight of approximately 150 kDa, herein named DCLP, was isolated from the stem of DCL, and its antioxidative, hypoglycemic and immune stimulating effects were evaluated using various in vitro and in vivo assay systems. DCLP inhibited hydroxyl radicals ($^{\cdot}$OH)-mediated deoxyribose degradation by scavenging hydroxyl radicals directly as well as by chelating iron ions. DCLP also showed dose-dependent scavenging activity on superoxide anions ($O_2^{{\cdot}-}$) and offered significant protection (p < 0.001) against glucose oxidase-mediated cytotoxicity in Jurkat cells. DCLP had immune stimulating effects, as evidenced by the DCLP-mediated increases in the level of DNA synthesis, viability, and cytokine secretion in mouse lymphocytes. Moreover, oral administration of DCLP produced a significant reduction in blood glucose level in alloxan-induced diabetic mice. These findings suggest that DCLP has a potential utility in treating patients who require enhanced antioxidation, immune function and/or hypoglycemic activity.