• Title/Summary/Keyword: Cellular pathway

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Effect of Atractylodis Rhizoma Alba on Osteoclast Formation (백출의 파골세포 분화에 미치는 영향)

  • Park, Sung-Tae;Lee, Myeung-Su;Jeon, Byung-Hun;Park, Kie-In;Oh, Jae-Min
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.25 no.1
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    • pp.109-114
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    • 2011
  • Atractylodis Rhizoma Alba is commonly used herbal medicine and it has been known that has immuno-regualtory effects and anti-cancer effects. The inhibition of osteoclastogenesis is essential for the prevention and treatment of osteoporosis. The aim of this study was to evaluate the effects of Atractylodis Rhizoma Alba on osteoclast differentiation in vitro and on resorbing activity of osteoclast. Osteoclast formation was evaluated in bone marrow cells (BMC) in the presence or absence of Atractylodis Rhizoma Alba. The expression of c-fos, tartrate-resistant acid phosphatase (TRAP), OSCAR, DC-STAMP, cathepsin K, MafB and NFATc1 mRNA in osteoclast precursor were assessed by RT-PCR. The levels of TNF receptor-associated factor-6 (TRAF-6), c-fos and NFATc1 protein were assessed by Western blot analysis. Also the correlation with MAPKs and NF-${\kappa}B$ pathways were measured by using Western blot analysis. With bone resorption study, I tried to evaluate the inhibitory effects of Atractylodis Rhizoma Alba on mature osteoclast function. Atractylodis Rhizoma Alba inhibited the RANKL induced osteoclastic differentiation from bone marrow macrophage in a dose dependant manner without cellular toxicity. Gene expression of c-fos and NFATc1 was significantly down regulated with Atractylodis Rhizoma Alba treatment. Atractylodis Rhizoma Alba markedly inhibited the RANKL-induced osteoclastogenesis through suppression of nuclear factor kappa b (NF-${\kappa}B$) pathway, down stream pathway of p38, ERK and JNK pathway. Taken together, I concluded that Atractylodis Rhizoma Alba have beneficial effect on osteoporosis by inhibition of osteoclast differentiation and by inhibition of functioning osteoclast. Thus I expect that Atractylodis Rhizoma Alba could be a treatment option for osteoporosis.

Role of Nitric Oxide in Pepsinogen Secretion from Rat Gastric Chief Cells

  • Sung, Dae-Suk;Seo, Dong-Wan;Choi, Don-Woong;Ahn, Seong-Hoon;Hong, Sung-Youl;Lee, Hoi-Young;Han, Jeung-Whan;Lee, Hyang-Woo
    • Biomolecules & Therapeutics
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    • v.7 no.2
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    • pp.105-111
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    • 1999
  • Nitric oxide (NO), a cellular messenger synthesized from L-arginine by NO synthase (NOS, EC.1.14.13.39), is considered to be a regulator of gastric secretion. In the present study, the role of NO in the regulation of exocrine secretion was investigated in rat gastric chief cells. Treatment of chief cells with carba-chol resulted in an increase in the arginine conversion to citrulline, the amount of $NO_{x}$, the release of pepsine-gen, and the level of cGMP Especially, carbachol-stimulated increase of arginine to citrulline transformation, the amount of $NO_{x}$, cGMP level and the release of pepsinogen were partially reduced by the natural NOS inhibitor, $N^{G}$-monomethyl-L-arginine (MMA) and $N^{G}$, $N^{G}$-dimethyl-L-arginine (DMA). Furthermore, MMA- and DMA-induced decrease of pepsinogen secretion showed dose-dependent patters. Activation of NOS is one of the early events in receptor-mediated cascade of reactions in gastric chief cells and NO, not completely, but partially mediates gastric secretion. Agonist-stimulated pepsinogen secretion in chief cells has been considered to be mediated in adenosine 3',5'-cyclic monophosphate pathway and/or guanosine 3', 5'-cyclic monophosphate (cGMP) pathway. Taken together, the above results suggest that partial decrease of exocrine secretion following treatment of NOS inhibitor may result from the inactivation of NOS and subsequent guano- late cyclase, and NO/cGMP pathway may play a pivotal role in exocrine secretion.

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P53 transcription-independent activity mediates selenite-induced acute promyelocytic leukemia NB4 cell apoptosis

  • Guan, Liying;Huang, Fang;Li, Zhushi;Han, Bingshe;Jiang, Qian;Ren, Yun;Yang, Yang;Xu, Caimin
    • BMB Reports
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    • v.41 no.10
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    • pp.745-750
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    • 2008
  • Selenium, an essential trace element possessing anti-carcinogenic properties, can induce apoptosis in cancer cells. We have previously shown that sodium selenite can induce apoptosis by activating the mitochondrial apoptosis pathway in NB4 cells. However, the detailed mechanism remains unclear. Presently, we demonstrate that p53 contributes to apoptosis by directing signaling at the mitochondria. Immunofluorescent and Western blot procedures revealed selenite-induced p53 translocation to mitochondria. Inhibition of p53 blocked accumulation of reactive oxygen species (ROS) and loss of mitochondrial membrane potential, suggesting that mitochondrial p53 acts as an upstream signal of ROS and activates the mitochondrial apoptosis pathway. Selenite also disrupted cellular calcium ion homeostasis in a ROS-dependent manner and increased mitochondrial calcium ion concentration. p38 kinase mediated phosphorylation and mitochondrial translocation of p53. Taken together, these results indicate that p53 involves selenite-induced NB4 cell apoptosis by translocation to mitochondria and activation mitochondrial apoptosis pathway in a transcription-independent manner.

Ethyl Acetate Fraction from Petasites japonicus Attenuates Oxidative Stress through Regulation of Nuclear Factor E2-Related Factor-2 Signal Pathway in LLC-PK1 Cells (머위 에틸아세테이트 분획물의 LLC-PK1 세포에서의 Nrf-2 매개 항산화 효과)

  • Kim, Ji Hyun;Lee, Jaemin;Lee, Sanghyun;Cho, Eun Ju
    • Korean Journal of Pharmacognosy
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    • v.47 no.1
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    • pp.55-61
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    • 2016
  • Antioxidant effects and nuclear factor E2-related factor-2 (Nrf-2) signal pathway of methanol extract and 4 fractions [n-hexane, methylene chloride, ethyl acetate (EtOAc), and n-butanol fractions] from Petasites japonicus were investigated. The EtOAc fraction showed highest polyphenol and flavonoid contents among other fractions. In addition, EtOAc fraction showed stronger scavenging activity against superoxide anion radical than other fractions. Furthermore, we investigated antioxidants effects of the EtOAc fraction under cellular system using $LLC-PK_1$ cells. The EtOAc fraction dose-dependently increased the antioxidant protein expressions of heme oxygenase 1 (HO-1) and thioredoxin reductase 1 (TrxR1) known to be involved in oxidative stress, through activation of Nrf-2. The treatment of EtOAc fraction ($100{\mu}g/mL$) led to the elevation of the high expression of Nrf-2-dependent factor such as HO-1 and TrxR1. These results indicated that the EtOAc fraction of P. japonicus showed high antioxidant activity by regulation of Nrf-2 signaling pathway.

Effects of Bisphosphonates on Glucose Transport in a Conditionally Immortalized Rat Retinal Capillary Endothelial Cell Line (TR-iBRB Cells)

  • Lee, Na-Young;Park, Hyun-Joo;Kang, Young-Sook
    • Biomolecules & Therapeutics
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    • v.24 no.1
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    • pp.94-98
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    • 2016
  • The objective of the present study was to elucidate the effect of bisphosphonates, anti-osteoporosis agents, on glucose uptake in retinal capillary endothelial cells under normal and high glucose conditions. The change of glucose uptake by pre-treatment of bisphosphonates at the inner blood-retinal barrier (iBRB) was determined by measuring cellular uptake of $[^3H]3$-O-methyl glucose (3-OMG) using a conditionally immortalized rat retinal capillary endothelial cell line (TR-iBRB cells) under normal and high glucose conditions. $[^3H]3$-OMG uptake was inhibited by simultaneous treatment of unlabeled D-glucose and 3-OMG as well as glucose transport inhibitor, cytochalasin B. On the other hand, simultaneous treatment of alendronate or pamidronate had no significant inhibitory effect on $[^3H]3$-OMG uptake by TR-iBRB cells. Under high glucose condition of TR-iBRB cells, $[^3H]3$-OMG uptake was increased at 48 h. However, $[^3H]3$-OMG uptake was decreased significantly by pre-treatment of alendronate or pamidronate compared with the values for normal and high glucose conditions. Moreover, geranylgeraniol (GGOH), a mevalonate pathway intermediate, increased the uptake of $[^3H]3$-OMG reduced by bisphosphonates pre-treatment. But, pre-treatment of histamine did not show significant inhibition of $[^3H]3$-OMG uptake. The glucose uptake may be down regulated by inhibiting the mevalonate pathway with pre-treatment of bisphosphonates in TR-iBRB cells at high glucose condition.

$p19^{ras}$ Accelerates $p73{\beta}$-mediated Apoptosis through a Caspase-3 Dependent Pathway

  • Jang, Sang-Min;Kim, Jung-Woong;Choi, Kyung-Hee
    • Animal cells and systems
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    • v.13 no.4
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    • pp.399-403
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    • 2009
  • $p19^{ras}$ is an alternative splicing variant of the proto-oncogene c-H-ras pre-mRNA of $p21^{ras}$. In contrast to $p21^{ras}$, $p19^{ras}$ does not have a C-terminal CAAX motif that targets the plasma membrane and is localized to both the cytoplasm and nucleus. We found that $p19^{ras}$ activated the transcriptional activity of $p73{\beta}$ through protein-protein interactions in the nucleus. p73 is known to play an important role in cellular damage responses such as apoptosis. Although p73 is a structural and functional homologue of p53, p73-mediated apoptosis has not yet been clearly elucidated. In this study, we demonstrate that the interaction between $p19^{ras}$ and $p73{\beta}$ accelerated $p73{\beta}$-induced apoptosis through a caspase-3 dependent pathway. Treatment with DEVD-CHO, a caspase inhibitor, also strengthened $p73{\beta}$-mediated apoptosis through a caspase-3 dependent pathway. Furthermore, the enhanced transcriptional activity of endogenous $p73{\beta}$ by treatment with Taxol was amplified by $p19^{ras}$ overexpression, which markedly increased caspase-3 dependent apoptosis in the p53-null SAOS2 cancer cell line. Our findings indicate a functional linkage between $p19^{ras}$ and p73 in caspase-3 mediated apoptosis of cancer cells.

PCNA Modifications for Regulation of Post-Replication Repair Pathways

  • Lee, Kyoo-young;Myung, Kyungjae
    • Molecules and Cells
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    • v.26 no.1
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    • pp.5-11
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    • 2008
  • Stalled DNA replication forks activate specific DNA repair mechanism called post-replication repair (PRR) pathways that simply bypass DNA damage. The bypassing of DNA damage by PRR prevents prolonged stalling of DNA replication that could result in double strand breaks (DSBs). Proliferating cell nuclear antigen (PCNA) functions to initiate and choose different bypassing pathways of PRR. In yeast, DNA replication forks stalled by DNA damage induces monoubiquitination of PCNA at K164, which is catalyzed by Rad6/Rad18 complex. PCNA monoubiquitination triggers the replacement of replicative polymerase with special translesion synthesis (TLS) polymerases that are able to replicate past DNA lesions. The PCNA interaction motif and/or the ubiquitin binding motif in most TLS polymerases seem to be important for the regulation of TLS. The TLS pathway is usually error-prone because TLS polymerases have low fidelity and no proofreading activity. PCNA can also be further polyubiquitinated by Ubc13/ Mms2/Rad5 complex, which adds an ubiquitin chain onto monoubiquitinated K164 of PCNA. PCNA polyubiquitination directs a different PRR pathway known as error-free damage avoidance, which uses the newly synthesized sister chromatid as a template to bypass DNA damage presumably through template switching mechanism. Mammalian homologues of all of the yeast PRR proteins have been identified, thus PRR is well conserved throughout evolution. Mutations of some PRR genes are associated with a higher risk for cancers in mice and human patients, strongly supporting the importance of PRR as a tumor suppressor pathway.

Quantitative Proteogenomics and the Reconstruction of the Metabolic Pathway in Lactobacillus mucosae LM1

  • Pajarillo, Edward Alain B.;Kim, Sang Hoon;Lee, Ji-Yoon;Valeriano, Valerie Diane V.;Kang, Dae-Kyung
    • Food Science of Animal Resources
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    • v.35 no.5
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    • pp.692-702
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    • 2015
  • Lactobacillus mucosae is a natural resident of the gastrointestinal tract of humans and animals and a potential probiotic bacterium. To understand the global protein expression profile and metabolic features of L. mucosae LM1 in the early stationary phase, the QExactiveTM Hybrid Quadrupole-Orbitrap Mass Spectrometer was used. Characterization of the intracellular proteome identified 842 proteins, accounting for approximately 35% of the 2,404 protein-coding sequences in the complete genome of L. mucosae LM1. Proteome quantification using QExactiveTM Orbitrap MS detected 19 highly abundant proteins (> 1.0% of the intracellular proteome), including CysK (cysteine synthase, 5.41%) and EF-Tu (elongation factor Tu, 4.91%), which are involved in cell survival against environmental stresses. Metabolic pathway annotation of LM1 proteome using the Kyoto Encyclopedia of Genes and Genomes (KEGG) database showed that half of the proteins expressed are important for basic metabolic and biosynthetic processes, and the other half might be structurally important or involved in basic cellular processes. In addition, glycogen biosynthesis was activated in the early stationary phase, which is important for energy storage and maintenance. The proteogenomic data presented in this study provide a suitable reference to understand the protein expression pattern of lactobacilli in standard conditions

Ginsenoside Rh2 epigenetically regulates cell-mediated immune pathway to inhibit proliferation of MCF-7 breast cancer cells

  • Lee, Hyunkyung;Lee, Seungyeon;Jeong, Dawoon;Kim, Sun Jung
    • Journal of Ginseng Research
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    • v.42 no.4
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    • pp.455-462
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    • 2018
  • Background: Ginsenoside Rh2 has been known to enhance the activity of immune cells, as well as to inhibit the growth of tumor cells. Although the repertoire of genes regulated by Rh2 is well-known in many cancer cells, the epigenetic regulation has yet to be determined, especially for comprehensive approaches to detect methylation changes. Methods: The effect of Rh2 on genome-wide DNA methylation changes in breast cancer cells was examined by treating cultured MCF-7 with Rh2. Pyrosequencing analysis was carried out to measure the methylation level of a global methylation marker, LINE1. Genome-wide methylation analysis was carried out to identify epigenetically regulated genes and to elucidate the most prominent signaling pathway affected by Rh2. Apoptosis and proliferation were monitored to examine the cellular effect of Rh2. Results: LINE1 showed induction of hypomethylation at specific CpGs by 1.6-9.1% (p < 0.05). Genome-wide methylation analysis identified the "cell-mediated immune response"-related pathway as the top network. Cell proliferation of MCF-7 was retarded by Rh2 in a dose-dependent manner. Hypermethylated genes such as CASP1, INSL5, and OR52A1 showed downregulation in the Rh2-treated MCF-7, while hypomethylated genes such as CLINT1, ST3GAL4, and C1orf198 showed upregulation. Notably, a higher survival rate was associated with lower expression of INSL5 and OR52A1 in breast cancer patients, while with higher expression of CLINT1. Conclusion: The results indicate that Rh2 induces epigenetic methylation changes in genes involved in immune response and tumorigenesis, thereby contributing to enhanced immunogenicity and inhibiting the growth of cancer cells.

Oleanolic acid 3-acetate, a minor element of ginsenosides, induces apoptotic cell death in ovarian carcinoma and endometrial carcinoma cells via the involvement of a reactive oxygen species-independent mitochondrial pathway

  • Jo, Hantae;Oh, Jeong-Hyun;Park, Dong-Wook;Lee, Changho;Min, Churl K.
    • Journal of Ginseng Research
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    • v.44 no.1
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    • pp.96-104
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    • 2020
  • Objectives: Oleanolic acid, a minor element of ginsenosides, and its derivatives have been shown to have cytotoxicity against some tumor cells. The impact of cytotoxic effect of oleanolic acid 3-acetate on ovarian cancer SKOV3 cells and endometrial cancer HEC-1A cells were examined both in vivo and in vitro to explore the underlying mechanisms. Methods: Cytotoxic effects of oleanolic acid 3-acetate were assessed by cell viability, phosphatidylserine exposure on the cell surface, mitochondrial release of cytochrome C, nuclear translocation of apoptosis-inducing factor, depolarization of mitochondrial transmembrane potential (∆Ψm), and generation of reactive oxygen species (ROS). In vivo inhibition of tumor growth was also assessed with xenografts in immunocompromised mice. Results: Oleanolic acid 3-acetate exhibited potent cytotoxicity toward SKOV3 and HEC-1A cells by decreasing cell viability in a concentration-dependent manner. Importantly, oleanolic acid 3-acetate effectively suppressed the growth of SKOV3 cell tumor xenografts in immunocompromised mice. Furthermore, oleanolic acid 3-acetate induced apoptotic cell death as revealed by loss of ∆Ψm, release of cytochrome c, and nuclear translocation of apoptosis-inducing factor with a concomitant activation of many proapoptotic cellular components including poly(ADP-ribose) polymerase, Bcl-2, and caspases-8, caspase-3, and caspase-7. Oleanolic acid 3-acetate, however, caused a decrease in ROS production, suggesting the involvement of an ROS-independent pathway in oleanolic acid 3-acetate-induced apoptosis in SKOV3 and HEC-1A cells. Conclusion: These findings support the notion that oleanolic acid 3-acetate could be used as a potent anticancer supplementary agent against ovarian and endometrial cancer. Oleanolic acid 3-acetate exerts its proapoptotic effects through a rather unique molecular mechanism that involves an unconventional ROS-independent but mitochondria-mediated pathway.