• Title/Summary/Keyword: ERK activation

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LPS Increases 5-LO Expression on Monocytes via an Activation of Akt-Sp1/NF-${\kappa}B$ Pathways

  • Lee, Seung Jin;Seo, Kyo Won;Kim, Chi Dae
    • The Korean Journal of Physiology and Pharmacology
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    • v.19 no.3
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    • pp.263-268
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    • 2015
  • 5-Lipoxygenase (5-LO) plays a pivotal role in the progression of atherosclerosis. Therefore, this study investigated the molecular mechanisms involved in 5-LO expression on monocytes induced by LPS. Stimulation of THP-1 monocytes with LPS ($0{\sim}3{\mu}g/ml$) increased 5-LO promoter activity and 5-LO protein expression in a concentration-dependent manner. LPS-induced 5-LO expression was blocked by pharmacological inhibition of the Akt pathway, but not by inhibitors of MAPK pathways including the ERK, JNK, and p38 MAPK pathways. In line with these results, LPS increased the phosphorylation of Akt, suggesting a role for the Akt pathway in LPS-induced 5-LO expression. In a promoter activity assay conducted to identify transcription factors, both Sp1 and NF-${\kappa}B$ were found to play central roles in 5-LO expression in LPS-treated monocytes. The LPS-enhanced activities of Sp1 and NF-${\kappa}B$ were attenuated by an Akt inhibitor. Moreover, the LPS-enhanced phosphorylation of Akt was significantly attenuated in cells pretreated with an anti-TLR4 antibody. Taken together, 5-LO expression in LPS-stimulated monocytes is regulated at the transcriptional level via TLR4/Akt-mediated activations of Sp1 and NF-${\kappa}B$ pathways in monocytes.

Mycobacterial Heparin-binding Hemagglutinin Antigen Activates Inflammatory Responses through PI3-K/Akt, NF-${\kappa}B$, and MAPK Pathways

  • Kim, Ki-Hye;Yang, Chul-Su;Shin, A-Rum;Jeon, So-Ra;Park, Jeong-Kyu;Kim, Hwa-Jung;Jo, Eun-Kyeong
    • IMMUNE NETWORK
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    • v.11 no.2
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    • pp.123-133
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    • 2011
  • Background: Mycobacterium tuberculosis (Mtb) heparin binding hemagglutinin (HBHA) is an Ag known to evoke effective host immune responses during tuberculosis infection. However, the molecular basis of the host immune response to HBHA has not been fully characterized. In this study, we examined the molecular mechanisms by which HBHA can induce the expression of proinflammatory cytokines in macrophages. Methods: HBHA-induced mRNA and protein levels of proinflammatory cytokines were determined in bone marrow-derived macrophages (BMDMs) using RT-PCR and ELISA analysis. The roles of intracellular signaling pathways for NF-${\kappa}B$, PI3-K/Akt, and MAPKs were investigated in macrophage proinflammatory responses after stimulation with HBHA. Results: HBHA robustly activated the expression of mRNA and protein of both TNF-${\alpha}$ and IL-6, and induced phosphorylation of NF-${\kappa}B$, Akt, and MAPKs in BMDMs. Both TNF-${\alpha}$ and IL-6 production by HBHA was regulated by the NF-${\kappa}B$, PI3-K, and MAPK pathways. Furthermore, PI3-K activity was required for the HBHA-induced activation of ERK1/2 and p38 MAPK, but not JNK, pathways. Conclusion: These data suggest that mycobacterial HBHA significantly induces proinflammatory responses through crosstalk between the PI3-K and MAPK pathways in macrophages.

Synergistic Effect of Interleukin-18 on the Expression of Lipopolysaccharide-Induced IP-10 (CXCL-10) mRNA in Mouse Peritoneal Macrophages

  • Kim, Hyo-Young;Kim, Jae-Ryong;Kim, Hee-Sun
    • Journal of Microbiology and Biotechnology
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    • v.16 no.10
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    • pp.1605-1612
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    • 2006
  • Interleukin (IL)-18, a member of the family of IL-l cytokine, is one of the principal inducers of $interferon-{\gamma}(IFN-{\gamma})$ in T lymphocytes and natural killer cells. The objective of the present study was to evaluate the effect of IL-18 on the expression of chemokine IP-10 (CXCL-10) mRNA in mouse peritoneal macrophages. IL-18 had very weak direct effect or synergistic effect with IL-12 on the expression of IP-10 mRNA in C57BL/6 mouse peritoneal macrophages. However, IL-18 pretreatment was found to playa cooperative role in the expression of lipopolysaccharide (LPS)-induced IP-10 mRNA. For the expression of LPS-induced IP-10 mRNA, the synergistic effect was detected after 16 h of IL-18 pretreatment prior to LPS stimulation. The expression level of CD14 in cells stimulated with LPS was not changed by IL-18 pretreatment, and the level of $IFN-{\gamma}$ production during IL-18 pretreatment plus LPS stimulation was barely discernible ($0.36{\pm}0.31pg/ml$). Namely, the synergistic effect of IL-18 pretreatment was not related to a change of LPS receptor, CD14 expression, and the production of $IFN-{\gamma}$ by the interaction between IL-18 and LPS. The synergistic effect of IL-18 pretreatment on the expression of LPS-induced IP-10 was related to not NF-kB but AP-1 activation, and associated with the extracellular signal-regulated kinase (ERK) pathway, one of the mitogen-activated protein kinase signaling pathways. These results provide useful information that may elucidate the mechanisms underlying the effect of IL-18 on the expression of IP-10 mRNA.

The Effects of Ionized Maifanite on Skin Damages of Nc/Nga Mice after Atopic Dermatitis Elicitation (이온화된 맥반석이 아토피 피부염 유발 Nc/Nga mice의 피부손상 및 염증 완화에 미치는 영향)

  • Kim, Jong-Chae;Hong, Seung-Ug
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.30 no.1
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    • pp.29-42
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    • 2017
  • Objectives : Atopic dermatitis accompanies with severe pruritus and collapse of skin barrier, inflammation. Maifanite could be used as an ointment for skin disease. However, there have been few studies about maifanite uses for atopic dermatitis. We report the anti-inflammatory and promoting skin recovery effects of ionized maifanite on damaged skin barrier with experimentally elicited atopic dermatitis. Methods : Nc/Nga mice were divided into 3 groups: control group(CON), atopic dermatitis elicited group(AE group), ionized maifanite treated group after atopic dermatitis elicitation(MT group). After 5% SDS was applied D. pteronyssinus crude extract also applied for 3 weeks to elicit atopic dermatitis-like skin disease. MT group was treated for 3 weeks with ionized maifanite. Ionized maifanite was applied once a day and voluntarily administrated. AE group and control group were treated with normal saline in the same way. Results : In MT group, skin lesions like eczema were more improved than AE group. p-ERK1/2 positive reaction was reduced in MT group. MMP-9 and substance P positive reaction at dermal papillae was also reduced in MT group. With skin angiogram, capillary vessel decreased in MT group. Also, IL-4 positive reaction cell and STAT-6 positive reaction cell reduced more in MT group than in AE group. $NF-{\kappa}B$ p65 positive reaction cell and iNOS positive reaction cell also declined more in MT group than in AE group. Conclusions : It is supposed that ionized maifanite has anti-inflammatory effects on NC/Nga mice's atopic dermatitis with suppressing IL-4 production and Th2 cell differentiation, and controlling $NF-{\kappa}B$ activation.

Anti-inflammatory Effects of Gagamsoyosan (가감조요산(加減造遙散)의 항염(抗炎) 및 면역반응(免疫反應)에 대한 연구(硏究))

  • Kim, Joo-Yeon;Lee, Soon-Yee;Cho, Han-Baek;Kim, Song-Baeg;Choe, Chang-Min
    • The Journal of Korean Obstetrics and Gynecology
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    • v.21 no.4
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    • pp.17-35
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    • 2008
  • Purpose: It is the purpose of this study to investigate the anti-inflammatory effects of water extract from Gagamsoyosan(GGSYS) on the peritoneal macrophage. Methods: To evaluate anti-inflammatory effects of GGSYS. inflammatory cytokines were measured in lipopolysaccharide(LPS) -stimulated macrophages. Furthermore. the western blot has been done to look into the molecular mechanism. Results: GGSYS did not have any cytotoxicity in the peritoneal macrophages and suppressed production of LPS-induced NO. tumor necrosis factor-alpha (TNF-$\alpha$). interleukin(IL)-1$\beta$. IL-6. IL-12. GGSYS inhibited the activation of extracelluar signal-regulated kinase (ERK1/2). c-Jun N-terminal kinase(JNK), p38 kinase and the degradation of inhibitory kappa B-alpha($I_{k}B-\alpha$) in the LPS-stimulated peritoneal macro phages. GGSYS inhibited LPS-induced endotoxin shock and the production of TNF-$\alpha$. IL-l$\beta$. IL-6 in serum from LPS-stimulated mice. Conclusion: These results suggest that GGSYS may have the anti-inflammatory effect which can inhibit the production of NO and inflammatory cytokines. GGSYS is expected to protect against inflammatory diseases.

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Suppression of Protein Kinase C and Nuclear Oncogene Expression as Possible Action Mechanisms of Cancer Chemoprevention by Curcumin

  • Lin, Jen-Kun
    • Archives of Pharmacal Research
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    • v.27 no.7
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    • pp.683-692
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    • 2004
  • Curcumin (diferuloylmethane) is a major naturally-occurring polyphenol of Curcuma species, which is commonly used as a yellow coloring and flavoring agent in foods. Curcumin has shown anti-carcinogenic activity in animal models. Curcumin possesses anti-inflammatory activity and is a potent inhibitor of reactive oxygen-generating enzymes such as lipoxygenase/cyclooxygenase, xanthine dehydrogenase/oxidase and inducible nitric oxide synthase; and an effective inducer of heme oxygenase-1. Curcumin is also a potent inhibitor of protein kinase C(PKC), EGF(Epidermal growth factor)-receptor tyrosine kinase and LĸB kinase. Subsequently, curcumin inhibits the activation of NF(nucleor factor)KB and the expressions of oncogenes including c-jun, c-fos, c-myc, NIK, MAPKs, ERK, ELK, PI3K, Akt, CDKs and iNOS. It is proposed that curcumin may suppress tumor promotion through blocking signal transduction path-ways in the target cells. The oxidant tumor promoter TPA activates PKC by reacting with zinc thiolates present within the regulatory domain, while the oxidized form of cancer chemopreventive agent such as curcumin can inactivate PKC by oxidizing the vicinal thiols present within the catalytic domain. Recent studies indicated that proteasome-mediated degradation of cell proteins playa pivotal role in the regulation of several basic cellular processes including differentiation, proliferation, cell cycling, and apoptosis. It has been demonstrated that curcumin-induced apoptosis is mediated through the impairment of ubiquitin-proteasome pathway. Curcumin was first biotransformed to dihydrocurcumin and tetrahydrocurcumin and that these compounds subsequently were converted to monoglucuronide conjugates. These results suggest that curcumin-glucuronide, dihydrocurcumin-glucuronide, tetrahydrocurcumin-glucuronide and tetrahydrocurcumin are the major metabolites of curcumin in mice, rats and humans.

Deoxypodophyllotoxin Inhibits Cell Growth and Induces Apoptosis by Blocking EGFR and MET in Gefitinib-Resistant Non-Small Cell Lung Cancer

  • Kim, Han Sol;Oh, Ha-Na;Kwak, Ah-Won;Kim, Eunae;Lee, Mee-Hyun;Seo, Ji-Hye;Cho, Seung-Sik;Yoon, Goo;Chae, Jung-Il;Shim, Jung-Hyun
    • Journal of Microbiology and Biotechnology
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    • v.31 no.4
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    • pp.559-569
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    • 2021
  • As one of the major types of lung cancer, non-small cell lung cancer (NSCLC) accounts for the majority of cancer-related deaths worldwide. Treatments for NSCLC includes surgery, chemotherapy, and targeted therapy. Among the targeted therapies, resistance to inhibitors of the epidermal growth factor receptor (EGFR) is common and remains a problem to be solved. MET (hepatocyte growth factor receptor) amplification is one of the major causes of EGFR-tyrosine kinase inhibitor (TKI) resistance. Therefore, there exists a need to find new and more efficacious therapies. Deoxypodophyllotoxin (DPT) extracted from Anthriscus sylvestris roots exhibits various pharmacological activities including anti-inflammation and anti-cancer effects. In this study we sought to determine the anti-cancer effects of DPT on HCC827GR cells, which are resistant to gefitinib (EGFR-TKI) due to regulation of EGFR and MET and their related signaling pathways. To identify the direct binding of DPT to EGFR and MET, we performed pull-down, ATP-binding, and kinase assays. DPT exhibited competitive binding with ATP against the network kinases EGFR and MET and reduced their activities. Also, DPT suppressed the expression of p-EGFR and p-MET as well as their downstreat proteins p-ErbB3, p-AKT, and p-ERK. The treatment of HCC827GR cells with DPT induced high ROS generation that led to endoplasmic-reticulum stress. Accordingly, loss of mitochondrial membrane potential and apoptosis by multi-caspase activation were observed. In conclusion, these results demonstrate the apoptotic effects of DPT on HCC827GR cells and signify the potential of DPT to serve as an adjuvant anti-cancer drug by simultaneously inhibiting EGFR and MET.

Rodgersia podophylla Leaves Suppress Inflammatory mediators through activation of Nrf2/HO-1 signaling, and inhibition of LPS-induced NF-κB and MAPKs signaling in RAW264.7 cells

  • Kim, Ha Na;Kim, Jeong Dong;Park, Su Bin;Jeong, Jin Boo
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2019.04a
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    • pp.94-94
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    • 2019
  • In this study, we elucidated the anti-inflammatory mechanisms of leaves extracts from Rodgersia podophylla (RPL) in RAW264.7 cells. RP-L significantly inhibited the production of the proinflammatory mediators such as NO, iNOS, IL-$1{\beta}$ and IL-6 in LPS-stimulated RAW264.7 cells. RPL increased HO-1 expression in RAW264.7 cells, and the inhibition of HO-1 by ZnPP reduced the inhibitory effect of RPL against LPS-induced NO production in RAW264.7 cells. Inhibition of p38, ROS and $GSK3{\beta}$ attenuated RPL-mediated HO-1 expression. Inhibition of ROS inhibited p38 phosphorylation and $GSK3{\beta}$ expression induced by RPL. In addition, inhibition of $GSK3{\beta}$ blocked RPL-mediated p38 phosphorylation. RPL induced nuclear accumulation of Nrf2, and Inhibition of p38, ROS and $GSK3{\beta}$ abolished RPL-mediated nuclear accumulation of Nrf2. Furthermore, RPL blocked LPS-induced degradation of $I{\kappa}B-{\alpha}$ and nuclear accumulation of p65. RP-L also attenuated LPS-induced phosphorylation of ERK1/2 and p38. Our results suggest that RPL exerts potential antiinflammatory activity by activating ROS/$GSK3{\beta}$/p38/Nrf2/HO-1 signaling and inhibiting NF-${\kappa}B$ and MAPK signaling in RAW264.7 cells. These findings suggest that RPL may have great potential for the development of anti-inflammatory drug.

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Anti-Inflammatory Activity of Acacia Honey through Inhibition of NF-κB and MAPK/ATF2 Signaling Pathway in LPS-Stimulated RAW264.7 Cells

  • Kim, Ha Na;Son, Kun Ho;Jeong, Hyung Jin;Park, Su Bin;Kim, Jeong Dong;Jeong, Jin Boo
    • Korean Journal of Plant Resources
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    • v.31 no.6
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    • pp.612-621
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    • 2018
  • Honey used as conventional medicine has various pharmacological properties. In the honey and anti-inflammatory effect, Gelam honey and Manuka honey has been reported to exert anti-inflammatory activity. However, the anti-inflammatory effect and potential mechanisms of acacia honey (AH) are not well understood. In this study, we investigated anti-inflammatory activity and mechanism of action of AH in LPS-stimulated RAW264.7 cells. AH attenuated NO production through inhibition of iNOS expression in LPS-stimulated RAW264.7 cells. AH also decreased the expressions of $IL-1{\beta}$, IL-6 and $TNF-{\alpha}$ as pro-inflammatory cytokines, and MCP-1 expression as a pro-inflammatory chemokine. In the elucidation of the molecular mechanisms, AH decreased LPS-mediated $I{\kappa}B$-${\alpha}$ degradation and subsequent nuclear accumulation of p65, which resulted in the inhibition of $NF-{\kappa}B$ activation in RAW264.7 cells. AH dose-dependently suppressed LPS-mediated phosphorylation of ERK1/2 and p38 in RAW264.7 cells. In addition, AH significantly inhibited ATF2 phosphorylation and nuclear accumulation of ATF2 in LPS-stimulated RAW264.7 cells. These results suggest that AH has an anti-inflammatory effect, inhibiting the production of pro-inflammatory mediators such as NO, iNOS, $TNF-{\alpha}$, IL-6, $IL-1{\beta}$ and MCP-1 via interruption of the $NF-{\kappa}B$ and MAPK/ATF2 signaling pathways.

Effect of Orostachys japonicus on Apoptosis and Autophagy in Human monocytic leukemia Cell line THP-1 via Inhibition of NF-κB and Phosphorylation of p38 MAPK (와송이 인간 백혈병 세포주 THP-1에서 NF-κB 활성 억제와 p38 활성을 통해 세포사멸과 자가포식에 미치는 영향)

  • Joo, Seonghee;Jang, Eungyeong;Kim, Youngchul
    • The Journal of Korean Medicine
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    • v.40 no.2
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    • pp.35-50
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    • 2019
  • Objectives: Orostachys japonicas (O. japonicus) has been known for its anti-tumor effect. In the present study, it was investigated whether O. japonicus EtOH extracts could induce apoptosis and autophagy which are part of the main mechanism related to anti-tumor effect in THP-1 cells. Methods: Cells were treated with various concentrations of O. japonicus EtOH extracts ($0-300{\mu}g/ml$) for 24, 48, and 72h. Cell viability was evaluated by MTS/PMS assay and apoptosis rate was examined by flow cytometry and ELISA assay. The mRNA expression of apoptosis-related genes (Bcl-2, Mcl-1, Survivin, Bax) and autophagy-related gene (mTOR) was evaluated using real-time PCR. The protein expression of Caspase-3, Akt, LC3 II, Beclin-1, Atg5, $NF-{\kappa}B$, p38, ERK was evaluated using western blot analysis. Results: O. japonicus EtOH extracts inhibited cell proliferation and apoptosis rate was increased in both flow cytometry and ELISA assay. Bcl-2, Mcl-1, Survivin (anti-apoptosis factors) mRNA expressions were decreased and Bax (pro-apoptosis factor) mRNA level was increased. mTOR mRNA expressions was decreased and LC3 II protein expressions was increased. Activation of $NF-{\kappa}B$ was decreased and phosphorylation of p38 was increased. Conclusion: O. japonicus is regarded to inhibit cell proliferation, to induce apoptosis and to regulate autophagy-related genes in THP-1 cells via $NF-{\kappa}B$ and p38 MAPK signaling pathway. This suggests O. japonicus could be an effective herb in treating acute myeloid leukemia.