• Title/Summary/Keyword: Nuclear Translocation

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Anti-Inflammatory Activity of Oligomeric Proanthocyanidins Via Inhibition of NF-κB and MAPK in LPS-Stimulated MAC-T Cells

  • Ma, Xiao;Wang, Ruihong;Yu, Shitian;Lu, Guicong;Yu, Yongxiong;Jiang, Caode
    • Journal of Microbiology and Biotechnology
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    • v.30 no.10
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    • pp.1458-1466
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    • 2020
  • Oligomeric proanthocyanidins (OPCs), classified as condensed tannins, have significant antioxidation, anti-inflammation and anti-cancer effects. This study was performed to investigate the anti-inflammatory effects of OPCs and the mechanism underlying these effects in lipopolysaccharide (LPS)-stimulated bovine mammary epithelial cells (MAC-T). Real-time PCR and ELISA assays indicated that OPC treatment at 1, 3 and 5 ㎍/ml significantly reduced the mRNA and protein, respectively, of oxidant indicators cyclooxygenase-2 (COX-2) (p < 0.05) and inducible nitric oxide synthase (iNOS) (p < 0.01) as well as inflammation cytokines interleukin (IL)-6 (p < 0.01), IL-1β (p < 0.01) and tumor necrosis factor-α (TNF-α) (p < 0.05) in LPS-induced MAC-T cells. Moreover, OPCs downregulated LPS-induced phosphorylation of p65 and inhibitor of nuclear factor kappa B (NF-κB) (IκB) in the NF-κB signaling pathway (p < 0.01), and they inhibited p65 translocation from the cytoplasm to the nucleus as revealed by immunofluorescence test and western blot. Additionally, OPCs decreased phosphorylation of p38, extracellular signal regulated kinase and c-jun NH2-terminal kinase in the MAPK signaling pathway (p < 0.01). In conclusion, the anti-inflammatory and antioxidant activities of OPCs involve NF-κB and MAPK signaling pathways, thus inhibiting expression of pro-inflammatory factors and oxidation indicators. These findings provide novel experimental evidence for the further practical application of OPCs in prevention and treatment of bovine mastitis.

Rifampicin Inhibits the LPS-induced Expression of Toll-like Receptor 2 via the Suppression of NF-${\kappa}B$ DNA-binding Activity in RAW 264.7 Cells

  • Kim, Seong-Keun;Kim, Young-Mi;Yeum, Chung-Eun;Jin, Song-Hyo;Chae, Gue-Tae;Lee, Seong-Beom
    • The Korean Journal of Physiology and Pharmacology
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    • v.13 no.6
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    • pp.475-482
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    • 2009
  • Rifampicin is a macrocyclic antibiotic which is used extensively for treatment against Mycobacterium tuberculosis and other mycobacterial infections. Recently, a number of studies have focused on the immune-regulatory effects of rifampicin. Therefore, we hypothesized that rifampicin may influence the TLR2 expression in LPS-activated RAW 264.7 cells. In this study, we determined that rifampicin suppresses LPS-induced TLR2 mRNA expression. The down-regulation of TLR2 expression coincided with decreased production of TNF-$\alpha$ Since NF-${\kappa}B$ is a major transcription factor that regulates genes for TLR2 and TNF-$\alpha$, we examined the effect of rifampicin on the LPS-induced NF-${\kappa}B$ activation. Rifampicin inhibited NF-${\kappa}B$ DNA-binding activity in LPS-activated RAW 264.7 cells, while it did not affect IKK$\alpha/\beta$ activity. However, rifampicin slightly inhibited the nuclear translocation of NF-${\kappa}B$ p65. In addition, rifampicin increased physical interaction between pregnane X receptor, a receptor for rifampicin, and NF-${\kappa}B$ p65, suggesting pregnane X receptor interferes with NF-${\kappa}B$ binding to DNA. Taken together, our results demonstrate that rifampicin inhibits LPS-induced TLR2 expression, at least in part, via the suppression of NF-${\kappa}B$ DNA-binding activity in RAW 264.7 cells. Thus, the present results suggest that the rifampicin-mediated inhibition of TLR2 via the suppression of NF-${\kappa}B$ DNA-binding activity may be a novel mechanism of the immune-suppressive effects of rifampicin.

Flavonoid Luteolin Inhibits LPS-induced Type I Interferon in Primary Macrophages (플라보노이드 루테올린의 lippopolysacharide로 유도한 type 1 interferon 억제 효과)

  • Jung, Won-Seok;Bae, Gi-Sang;Cho, Chang-Re;Park, Kyoung-Chel;Koo, Bon-Soon;Kim, Min-Sun;Ham, Kyung-Wan;Jo, Beom-Yeon;Cho, Gil-Hwan;Seo, Sang-Wan;Lee, Si-Woo;Song, Ho-Joon;Park, Sung-Joo
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.23 no.5
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    • pp.986-992
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    • 2009
  • Type I interferons (IFNs) are critical mediators of the innate immune system to defend viral infection. Interferon regulatory factor (IRF) and signal transducer and activator of transcription (STAT) play critical roles in type I IFN production in response to viral infection. Luteolin is natural polyphenolic compounds that have anti-inflammatory, cytoprotective and anti-carcinogenic effects. However, the mechanism of action and impact of luteolin on innate immunity is still unknown. In this study, we examined the effects of luteolin on the lipopolysacchride (LPS)-induced inflammatory responses. Luteolin inhibited Type I IFNs expression of mRNA and increased interleukin(IL)-10 expression of mRNA. Next, we examined the protective effects of IL-10 using IL-10 neutralizing antibody (IL-10NA). Blockade of IL-10 action didn't cause a significant reduction of Type I IFNs than LPS-induced luteolin pretreatment. Pretreatment of luteolin inhibited the level of IRF-1, and IRF-7 mRNA and the nuclear translocation of IRF-3. Also, luteolin reduced the activation of STAT - 1, 3. Theses results suggest that luteolin inhibits LPS-induced the production of Type I IFNS by both IRFs and STATs not IL-10 and may be a beneficial drug for the treatment of inflammatory disease.

SUPPRESSION OF PHORBOL ESTER-INDUCED EXPRESSION OF CYCLLOOXYGENASE-2 AND INDUCIBLE NITRIC OXIDE SYNTHASE BY SELCTED CHEMOPREVENTIVE PHYTOCHEMICALS VIA DOWN-REGULATION OF NF-$\textsc{k}$B

  • Surh, Young-Joon
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2002.05b
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    • pp.88.2-98
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    • 2002
  • A wide arry of naturally occurring substances particularly those present in dietary and medicinal plants, have been reported to possess substantial cancer chemopreventive properties. Certain phytochemicals retain strong antioxidative and anti-inflammatory properties which appear to contribute to their chemopreventive or chemoprotective activities. Inducible cyclooxygenase(COX-2) and nitric oxide synthase (iNOS) are important enzymes that mediate inflammatory processes. There is some evidence that expression of both COX-2 and iNOS is co-regulated by the eukaryotic transcription factor NF-$textsc{k}$B. Increased expression of COX-2 and/or iNOS has been associated with pathophysiology of certain types of human cancers as well as inflammatory diseases. Since inflammation is closely linked to tumor promotion, substances with potent anti-inflammatory activies are anticipated to exert chemopreventive effects on carcinogenesis, particularly in the promotion stage. An example is curcumin, a yellow pigment of turmeric (Curcuma longa L., Zingiberaceae), that strongly occurring diaryl heptanoids structurally related to curcumin have substantial anti-tumor promotional activities in two-stage mouse skin carcinogenesis. Thus, yakuchinone A [1-(4'-hydroxy-3'-methoxyphenyl)-7-phenyl-3heptanone] and yakuchinone B [1-(4'-hydroxy-3'methoxyphenyl)-7-phenylhept-1-en-3-one] present in Alpinia oxyphylla Miquel (Zingiberacease) attenuate phorbol ester-induced inflammation and papilloma formation in female ICR mice. These diarylheptanoids also suppressed phorbol ester-induced activation of epdermal ornithine decarboxylase and its mRNA expression when applied onto shaven backs of mice. Yakuchinone A and B as well as curcumin inhibited phorbol ester-induced expression of COX-2 and iNOS and their mRNA in mouse skin via inactivation of NF-$textsc{k}$B. Capsaicin, a major pungent ingredient of red pepper also attenuated phorbol ester-induced NF-$textsc{k}$B activation. Similar suppression of COX-2 and iNOS and down-regulation of NF-$textsc{k}$B activation for its DNA binding were observed with the ginsenosied Rg3 and the ethanol extract of Artemisia asiatica. We have also found that certain anti-inflammatory phytochemicals exert inhibitory effects on phorbol ester-induced COX-2 expression and NF-$textsc{k}$B activation in immortalized human breast epithelial (MCF-10A) cells in culture. One of the plausible mechanisms undelying inhibition by aforementioned phytochemicals of phorbol ester-induced NF-$textsc{k}$B activation involves interference with degragation of the inhibitory unit, I$textsc{k}$Ba, which blocks subsequent nuclear translocation of the functionally active p65 subunit of NF-$textsc{k}$B. the activation of epidermal NF-$textsc{k}$B by phorbol ester and subsequent induction of COX-2 hence appear to play an important role in intracellular signaling pathwasy leading to tumor promotion and targeted inhibition of NF-$textsc{k}$B may provide a new promising cancer chemopreventive strategy.

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4-O-Methylhonokiol Protects HaCaT Cells from TGF-β1-Induced Cell Cycle Arrest by Regulating Canonical and Non-Canonical Pathways of TGF-β Signaling

  • Kim, Sang-Cheol;Kang, Jung-Il;Hyun, Jin-Won;Kang, Ji-Hoon;Koh, Young-Sang;Kim, Young-Heui;Kim, Ki-Ho;Ko, Ji-Hee;Yoo, Eun-Sook;Kang, Hee-Kyoung
    • Biomolecules & Therapeutics
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    • v.25 no.4
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    • pp.417-426
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    • 2017
  • 4-O-methylhonokiol, a neolignan compound from Magnolia Officinalis, has been reported to have various biological activities including hair growth promoting effect. However, although transforming growth factor-${\beta}$ (TGF-${\beta}$) signal pathway has an essential role in the regression induction of hair growth, the effect of 4-O-methylhonokiol on the TGF-${\beta}$ signal pathway has not yet been elucidated. We thus examined the effect of 4-O-methylhonokiol on TGF-${\beta}$-induced canonical and noncanonical pathways in HaCaT human keratinocytes. When HaCaT cells were pretreated with 4-O-methylhonokiol, TGF-${\beta}1$-induced G1/G0 phase arrest and TGF-${\beta}1$-induced p21 expression were decreased. Moreover, 4-O-methylhonokiol inhibited nuclear translocation of Smad2/3, Smad4 and Sp1 in TGF-${\beta}1$-induced canonical pathway. We observed that ERK phosphorylation by TGF-${\beta}1$ was significantly attenuated by treatment with 4-O-methylhonokiol. 4-O-methylhonokiol inhibited TGF-${\beta}1$-induced reactive oxygen species (ROS) production and reduced the increase of NADPH oxidase 4 (NOX4) mRNA level in TGF-${\beta}1$-induced noncanonical pathway. These results indicate that 4-O-methylhonokiol could inhibit TGF-${\beta}1$-induced cell cycle arrest through inhibition of canonical and noncanonical pathways in human keratinocyte HaCaT cell and that 4-O-methylhonokiol might have protective action on TGF-${\beta}1$-induced cell cycle arrest.

Transcriptional Regulation of Human GD3 Synthase (hST8Sia I) by Fenretinide in Human Neuroblastoma SH-SY-5Y Cells (사람 신경모세포종 세포주 SH-SY5Y에서 fenretinide에 의한 GD3합성효소(hST8Sia I)의 전사조절기작)

  • Kang, Nam-Young;Kwon, Haw-Young;Lee, Young-Choon
    • Journal of Life Science
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    • v.20 no.9
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    • pp.1332-1338
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    • 2010
  • To elucidate the mechanism underlying the regulation of hST8Sia I gene expression in FenR-induced SH-SY5Y cells, we characterized the promoter region of the hST8Sia I gene. Functional analysis of the 5'-flanking region of the hST8Sia I gene showed that the -1146 to -646 region functions as the FenR-inducible promoter of hST8Sia I in SH-SY5Y cells. Site-directed mutagenesis indicated that the NF-&B binding site at -731 to -722 was crucial for the FenR-induced expression of hST8Sia I in SH-SY5Y cells. To investigate which signal transduction pathway was involved in FenR-stimulated induction of hST8Sia I in SH-SY5Y cells, we performed Western blot analysis using phospho-specific antibodies in order to measure their degree of regulatory phosphorylation. Phosphorylations of AKT and RelA (p65) subunit of NF-${\kappa}B$ were significantly elevated in cytosolic and nuclear fractions of FenR-stimulated SH-SY5Y cells, respectively, than in control or DMSO-treated SH-SY5Y cells. These results suggest that FenR induce transcriptional up-regulation of hST8Sia I gene expression through translocation of RelA (p65) subunit of NF-${\kappa}B$ to nucleus by AKT signal pathway in SH-SY5Y cells.

PKM2 Regulates Hepatocellular Carcinoma Cell Epithelial-mesenchymal Transition and Migration upon EGFR Activation

  • Fan, Fang-Tian;Shen, Cun-Si;Tao, Li;Tian, Chao;Liu, Zhao-Guo;Zhu, Zhi-Jie;Liu, Yu-Ping;Pei, Chang-Song;Wu, Hong-Yan;Zhang, Lei;Wang, Ai-Yun;Zheng, Shi-Zhong;Huang, Shi-Le;Lu, Yin
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.5
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    • pp.1961-1970
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    • 2014
  • Pyruvate kinase isozyme type M2 (PKM2) was first found in hepatocellular carcinoma (HCC), and its expression has been thought to correlate with prognosis. A large number of studies have demonstrated that epithelial-mesenchymal transition (EMT) is a crucial event in hepatocellular carcinoma (HCC) and associated metastasis, resulting in enhanced malignancy of HCC. However, the roles of PKM2 in HCC EMT and metastasis remain largely unknown. The present study aimed to determine the effects of PKM2 in EGF-induced HCC EMT and elucidate the molecular mechanisms in vitro. Our results showed that EGF promoted EMT in HCC cell lines as evidenced by altered morphology, expression of EMT-associated markers, and enhanced invasion capacity. Furthermore, the present study also revealed that nuclear translocation of PKM2, which is regulated by the ERK pathway, regulated ${\beta}$-catenin-TCF/LEF-1 transcriptional activity and associated EMT in HCC cell lines. These discoveries provide evidence of novel roles of PKM2 in the progression of HCC and potential therapeutic target for advanced cases.

Protein transduction of an antioxidant enzyme: subcellular localization of superoxide dismutase fusion protein in cells

  • Kim, Dae-Won;Kim, So-Young;Lee, Hwa;Lee, Yeum-Pyo;Lee, Min-Jung;Jeong, Min-Seop;Jang, Sang-Ho;Park, Jin-Seu;Lee, Kil-Soo;Kang, Tae-Cheon;Won, Moo-Ho;Cho, Sung-Woo;Kwon, Oh-Shin;Eum, Won-Sik;Choi, Soo-Young
    • BMB Reports
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    • v.41 no.2
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    • pp.170-175
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    • 2008
  • In protein therapy, it is important for exogenous protein to be delivered into the target subcellular localization. To transduce a therapeutic protein into its specific subcellular localization, we synthesized nuclear localization signal (NLS) and membrane translocation sequence signal (MTS) peptides and produced a genetic in-frame SOD fusion protein. The purified SOD fusion proteins were efficiently transduced into mammalian cells with enzymatic activities. Immunofluorescence and Western blot analysis revealed that the SOD fusion proteins successfully transduced into the nucleus and the cytosol in the cells. The viability of cells treated with paraquat was markedly increased by the transduced fusion proteins. Thus, our results suggest that these peptides should be useful for targeting the specific localization of therapeutic proteins in various human diseases.

Anti-inflammatory Effects of Illicium verum Hook. f. via Suppression of NFκB Pathway (NF-κB 억제를 통한 대회향(大茴香)의 항염증효능)

  • Keum, Soo Yeon;Park, Sang Mi;Jegal, Kyung Hwan;Hwangbo, Min;Cho, Il Je;Park, Chung A;Kim, Sang Chan;Jee, Seon Young
    • Herbal Formula Science
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    • v.24 no.4
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    • pp.243-257
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    • 2016
  • Objectives : Illicium verum Hook. f. has been known to possess antimicrobial, antioxidant, antifungal, anti-inflammatory, insecticidal, analgesic, sedative, convulsive activities, it has been rarely conducted to evaluate the immuno-biological activity. The present study was examined to evaluate the anti-inflammatory effects of the Illicium verum Hook. f. water extracts (IVE) in vivo and in vitro. Methods : Cell viability was measured by MTT assay. The relative levels of NO were measured with Griess reagent. iNOS, COX-2, $NF-{\kappa}B$ and target proteins were detected by immunoblot analysis, and levels of cytokines were analyzed by ELISA kit. Anti-edema effect was determined in the carrageenan (CA)-induced paw edema model in rats. Results : All dosages of IVE used in MTT assay had no significant cytotoxicity. The increases of NO production and iNOS expression were detected in LPS-treated cells compared with control. However, these increases were attenuated by treatment with IVE. Also, IVE reduced the elevated production of $TNF-{\alpha}$, $IL-1{\beta}$ and IL-6 by LPS. IVE inhibited the $p-I{\kappa}B$ and translocation of $NF-{\kappa}B$ to nuclear. Furthermore, IVE significantly inhibited the increases of hind paw swelling, skin thicknesses and inflammatory cell infiltrations induced by CA injection. Therefore, IVE will be favorably inhibited the acute edematous inflammations. Conclusion : These results provide evidences that anti-inflammatory effect of IVE is partly due to the reduction of some inflammatory mediators by suppression of $NF-{\kappa}B$ pathway.

Induction of Apoptosis by Citri Pericarpium Methanol Extract through Reactive Oxygen Species Generation in U937 Human Leukemia Cells (진피 메탄올 추출물의 활성산소종 생성을 통한 인체 백혈병 세포의 apoptosis 유발)

  • Kim, Ga Hee;Lee, Moon Hee;Han, Min Ho;Park, Cheol;Hong, Su Hyun;Choi, Yung Hyun
    • Journal of Life Science
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    • v.23 no.8
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    • pp.1057-1063
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    • 2013
  • Citri Pericarpium is one of the most commonly used traditional herbal medicines in Korea, China, and Japan. Its extracts have many properties including the treatment of indigestion and inflammatory respiratory syndromes such as bronchitis and asthma. However, the underlying molecular mechanisms of anti-cancer activity and molecular targets are not fully understood. In this work, we investigated the anti-proliferative activity of Citri Pericapium (EMCP) methanol extract on reactive oxygen species (ROS) production and the association of these effects with apoptotic cell death using U937 human leukemia cells in vitro. EMCP treatment decreased cell proliferation in a dose-dependent manner following an increase of the sub-G1 phase, the down-regulation of Bax proteins, the activation of caspases, the degradation of poly (ADP-ribose) polymerase proteins (PARP), and the induction of ROS generation. However, the quenching of ROS generation by N-acetyl-L-cysteine administration, a scavenger of ROS, reversed the EMCP-induced apoptosis effects. In addition, heme oxygenase-1 expression also recovered by inhibiting the nuclear translocation of phosphorylated NF-E2-related factor 2. Taken together, our data indicate that ROS are involved as key mediators in the early molecular events in the EMCP-induced apoptotic pathway.