• Title/Summary/Keyword: ERK activation

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Growth Inhibitory Activity of Honokiol through Cell-cycle Arrest, Apoptosis and Suppression of Akt/mTOR Signaling in Human Hepatocellular Carcinoma Cells

  • Hong, Ji-Young;Park, Hyen Joo;Bae, KiHwan;Kang, Sam Sik;Lee, Sang Kook
    • Natural Product Sciences
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    • v.19 no.2
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    • pp.155-159
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    • 2013
  • Honokiol, a naturally occurring neolignan mainly found in Magnolia species, has exhibited a potential anti-proliferative activity in human cancer cells. However, the growth inhibitory activity against hepatocellular carcinoma cells and the underlying molecular mechanisms has been poorly determined. The present study was designed to examine the anti-proliferative effect of honokiol in SK-HEP-1 human hepatocellular cancer cells. Honokiol exerted anti-proliferative activity with cell-cycle arrest at the G0/G1 phase and sequential induction of apoptotic cell death. The cell-cycle arrest was well correlated with the down-regulation of checkpoint proteins including cyclin D1, cyclin A, cyclin E, CDK4, PCNA, retinoblastoma protein (Rb), and c-Myc. The increase of sub-G1 peak by the higher concentration of honokiol ($75{\mu}M$) was closely related to the induction of apoptosis, which was evidenced by decreased expression of Bcl-2, Bid, and caspase-9. Hohokiol was also found to attenuate the activation of signaling proteins in the Akt/mTOR and ERK pathways. These findings suggest that the anti-proliferative effect of honokiol was associated in part with the induction of cell-cycle arrest, apoptosis, and dow-nregulation of Akt/mTOR signaling pathways in human hepatocellular cancer cells.

Cytoprotective Mechanism of Cyanidin and Delphinidin against Oxidative Stress-Induced Tenofibroblast Death

  • Nam, Dae Cheol;Hah, Young Sool;Nam, Jung Been;Kim, Ra Jeong;Park, Hyung Bin
    • Biomolecules & Therapeutics
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    • v.24 no.4
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    • pp.426-432
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    • 2016
  • Age-related rotator cuff tendon degeneration is related to tenofibroblast apoptosis. Anthocyanins reduce oxidative stress-induced apoptotic cell death in tenofibroblasts. The current study investigated the presence of cell protective effects in cyanidin and delphinidin, the most common aglycon forms of anthocyanins. We determined whether these anthocyanidins have antiapoptotic and antinecrotic effects in tenofibroblasts exposed to $H_2O_2$, and evaluated their biomolecular mechanisms. Both cyanidin and delphinidin inhibited $H_2O_2$-induced apoptosis in a dose-dependent manner. However, at concentrations of $100{\mu}g/ml$ or greater, delphinidin showed cytotoxicity against tenofibroblasts and a decreased antinecrotic effect. Cyanidin and delphinidin both showed inhibitory effects on the $H_2O_2$-induced increase in intracellular ROS formation and the activation of ERK1/2 and JNK. In conclusion, both cyanidin and delphinidin have cytoprotective effects on cultured tenofibroblasts exposed to $H_2O_2$. These results suggest that cyanidin and delphinidin are both beneficial for the treatment of oxidative stress-mediated tenofibroblast cell death, but their working concentrations are different.

Amphetamine-induced ERM Proteins Phosphorylation Is through $PKC{\beta}$ Activation in PC12 Cells

  • Jeong, Ha-Jin;Kim, Jeong-Hoon;Jeon, Song-Hee
    • The Korean Journal of Physiology and Pharmacology
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    • v.15 no.4
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    • pp.245-249
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    • 2011
  • Amphetamine, a synthetic psychostimulant, is transported by the dopamine transporter (DAT) to the cytosol and increases the exchange of extracellular amphetamine by intracellular dopamine. Recently, we reported that the phosphorylation levels of ezrin-radixin-moesin (ERM) proteins are regulated by psychostimulant drugs in the nucleus accumbens, a brain area important for drug addiction. However, the significance of ERM proteins phosphorylation in response to drugs of abuse has not been fully investigated. In this study, using PC12 cells as an in vitro cell model, we showed that amphetamine increases ERM proteins phosphorylation and protein kinase C (PKC) ${\beta}$ inhibitor, but not extracellular signal-regulated kinase (ERK) or phosphatidylinositol 3-kinases (PI3K) inhibitors, abolished this effect. Further, we observed that DAT inhibitor suppressed amphetamine-induced ERM proteins phosphorylation in PC12 cells. These results suggest that $PKC{\beta}$-induced DAT regulation may be involved in amphetmaine-induced ERM proteins phosphorylation.

Neuroprotective Effect of Wogonin: Potential Roles of Inflammatory Cytokines

  • Piao, Hua-Zi;Jin, Shun-Ai;Chun, Hyang-Sook;Lee, Jae-Chul;Kim, Won-Ki
    • Archives of Pharmacal Research
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    • v.27 no.9
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    • pp.930-936
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    • 2004
  • Wogonin (5,7-dihydroxy-8-methoxyflavone), an active component originated from the root of Scutellaria baicalensis Georgi, has been reported to possess antioxidant and anti-inflamma-tory properties. In this study, we investigated the neuroprotective effect of wogonin in a focal cerebral ischemia rat model. Wogonin markedly reduced the infarct volume after 2 h middle cerebral artery occlusion followed by 22 h reperfusion. Wogonin decreased the production of nitric oxide and inflammatory cytokines such as TNF-$\alpha$ and IL-6 in lipopolisaccharide-stimu-lated microglial cells. While wogonin reduced the activity of NF-$textsc{k}$B, it did not change the activ-ity of mitogen-activated protein kinases family members, p38, ERK and JNK. The lipopolisaccharide-stimulated production of NO and cytokines was significantly blocked by vari-ous kinds of NF-$textsc{k}$B inhibitors such as N-acetyl cysteine, pyrrolidinedithiocarbamate and MG-132. The data may indicate that wogonin has neuroprotective effect by preventing the over-activation of microglial cells, possibly by inactivating NF-$textsc{k}$B signaling pathway

Anti-inflammatory effect of extract of Pulsatilla koreana $N_{AKAI}$ in LPS-stimulated Murine peritoneal macrophage (LPS 로 활성화된 복강 대식세포에서 백두옹 추출물의 항염증 효과)

  • Park, Sung-Joo;Song, Ho-Joon
    • The Korea Journal of Herbology
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    • v.22 no.1
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    • pp.111-117
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    • 2007
  • Objectives : The purpose of this study was to investigate the anti-inflammatory effects of extract from Pulsatilla koreana $N_{AKAI}$ (PK) on the peritoneal macrophage. Methods : To evaluate of anti-inflammatory of PK, we examined cytokines and NO production in lipopolysacchride (LPS)-induced macrophages. Furthermore, we examined molecular mechanism using western blot. Results : 1.Extract from PK reduced LPS-induced NO, tumor necrosis factor-a ($TNF-{\alpha}$), interleukin (IL)-6 and IL-12 production in peritoneal macrophages. 2.Extract from PK itself does not have any cytotoxic effect. PK inhibited the activation of extracelluar signal-regulated kinase(ERK 1/2) but not another mitogen-activated protein kinases (MAPKs) such as p38, c-Jun NH2-terminal kinase (JNK) and the degradation of inhibitory kappa B a ($I_{k}B_{a}$) does not any effect in the LPS-stimulated peritoneal macrophages. Conclusion : PK down-regulated LPS-induced NO and cytokines production, which may be provide a clinical basis for anti-inflammatory properties of PK.

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Antioxidant Effect of Homogentisic Acid on Hydrogen Peroxide Induced Oxidative Stress in Human Lung Fibroblast Cells

  • Kang, Kyoung-Ah;Chae, Sung-Wook;Lee, Kyoung-Hwa;Zhang, Rui;Jung, Myung-Sun;You, Ho-Jin;Kim, Jin-Sook;Hyun, Jin-Won
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.10 no.6
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    • pp.556-563
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    • 2005
  • Homogentisic acid was found to scavenge intracellular reactive oxygen species (ROS), and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and thus prevented lipid peroxidation in human fibroblast (Wl 38) cells. The radical scavenging activity of homogentisic acid was found to protect Wl 38 cells against hydrogen peroxide $(H_2O_2)$ induced oxidative stress, via the activation of extracellular signal regulated kinase (ERK) protein. Homogentisic acid increased the activity of catalase. Hence, from the present study, it is suggested that homogentisic acid protects Wl 38 cells against $H_2O_2$ damage by enhancing the intracellular antioxidative activity.

Effects of Low Dose Gamma Irradiation on the Inflammatory Response in Spleen Cells (저선량 감마선 노출에 의한 비장세포의 염증 유발 작용에 대한 연구)

  • Sohn, Eun-Hwa
    • KSBB Journal
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    • v.28 no.6
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    • pp.415-422
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    • 2013
  • Gamma irradiation (${\gamma}IR$) is widely used for radiotherapy as a treatment of cancer cells although it has a risk to damage normal cells. Inflammation is regarded as one of side effects of ${\gamma}IR$ while the effect of low dose of ${\gamma}IR$ on inflammation has not been researched well. Here, we investigated the inflammatory responses of low dose of ${\gamma}IR$ on murine spleen cells. It was evaluated if ${\gamma}IR$ affected the mitogen-induced lymphocyte proliferation, the regulation of various inflammatory cytokines (IFN-${\gamma}$, IL-2, IL-17, IL-4, IL-10), and the involvement of Ikaros and MAPK/NF-${\kappa}B$ medicated mechanism. Exposure of $^{137}Cs-{\gamma}IR$ below 2 Gy decreased the lymphocytes proliferative response to mitogens (LPS, ConA) except at the lowest dose, 0.05 Gy. IL-17, IL-2 and IL-4 mRNA increased at 0.5 and 2 Gy, but not altered at 0.05 Gy. IL-10, anti-inflammatory cytokine, increased only at 0.05 Gy. In regard to intracellular signaling, p-JNK, p-p38 and p-$I{\kappa}B{\alpha}$ were not changed, whereas the activation of ERK and Ikaros increased at the lowest dose. These results suggest that exposure of ${\gamma}IR$ less than 0.5 Gy (or below 0.05 Gy) has beneficial effects as a radiation hormesis on immune function.

Antimicrobial peptide scolopendrasin VII, derived from the centipede Scolopendra subspinipes mutilans, stimulates macrophage chemotaxis via formyl peptide receptor 1

  • Park, Yoo Jung;Lee, Ha Young;Jung, Young Su;Park, Joon Seong;Hwang, Jae Sam;Bae, Yoe-Sik
    • BMB Reports
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    • v.48 no.8
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    • pp.479-484
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    • 2015
  • In this study, we report that one of the antimicrobial peptides scolopendrasin VII, derived from Scolopendra subspinipes mutilans, stimulates actin polymerization and the subsequent chemotactic migration of macrophages through the activation of ERK and protein kinase B (Akt) activity. The scolopendrasin VII-induced chemotactic migration of macrophages is inhibited by the formyl peptide receptor 1 (FPR1) antagonist cyclosporine H. We also found that scolopendrasin VII stimulate the chemotactic migration of FPR1-transfected RBL-2H3 cells, but not that of vector-transfected cells; moreover, scolopendrasin VII directly binds to FPR1. Our findings therefore suggest that the antimicrobial peptide scolopendrasin VII, derived from Scolopendra subspinipes mutilans, stimulates macrophages, resulting in chemotactic migration via FPR1 signaling, and the peptide can be useful in the study of FPR1-related biological responses. [BMB Reports 2015; 48(8): 479-484]

YAC tripeptide of epidermal growth factor promotes the proliferation of HaCaT keratinocytes through activation of EGFR

  • Yoo, Yeon Ho;Kim, Yu Ri;Kim, Min Seo;Lee, Kyoung-Jin;Park, Kyeong Han;Hahn, Jang-Hee
    • BMB Reports
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    • v.47 no.10
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    • pp.581-586
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    • 2014
  • Epidermal growth factor (EGF) is known to play key roles in skin regeneration and wound-healing. Here, we demonstrate that Pep2-YAC, a tripeptide covering residues 29-31 in the B loop of EGF, promotes the proliferation of HaCaT keratinocytes with activity comparable to EGF. The treatment of HaCaT cells with Pep2-YAC induced phosphorylation, internalization, and degradation of EGFR and organization of signaling complexes, which consist of Grb2, Gab1, SHP2, and PI3K. In addition, it stimulated the phosphorylation of ERK1/2 at Thr 202/Tyr 204 and of Akt1 at Ser 473 and the nuclear translocation of EGFR, STAT3, c-Jun, and c-Fos. These results suggest that Pep2-YAC may be useful as a therapeutic agent for skin regeneration and wound-healing as an EGFR agonist.

The Effect of Poria cocos Extract to Inhibit Enterovirus Replication (적복령 추출물의 심근염 유발 엔테로바이러스 증식 억제 효과)

  • Han, Jae-Young;Kim, Jin Hee;Lim, Byung-Kwan
    • Korean Journal of Pharmacognosy
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    • v.47 no.2
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    • pp.137-142
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    • 2016
  • Enterovirus is a common cause of several severe diseases such as myocarditis, hand-foot-mouth disease, and meningitis in children and adult. There are many try to develop new antiviral drug for direct treatment in virus infection. However, synthetic chemical antiviral drug is not working. To overcome this limitation, we examined plant extracts. The antiviral effect of plant extracts was screened by HeLa cell survival assay in coxsackievirus B3 (CVB3) infection. We observed a strong antiviral effect of Poria cocos extract in a dose-dependent manner (1 mg/ml~0.01 mg/ml). P. cocos extract (1 mg/ml) treatment was dramatically decreased virus protease 2A induced eIF4G-I cleavage and virus capsid protein VP1 production. CVB3 positive and negative strand RNA amplification were significantly reduced in P. cocos extract treatment. P. cocos extract completely blocked early time activation of ERK and AKT activity in CVB3 infection. Taken together these data indicate that the treatment of P. cocos extract strongly inhibit CVB3 replication. Poria cocos extract may possible to developed as a therapeutic agent for enterovirus.