• 제목/요약/키워드: STAT6 phosphorylation

검색결과 47건 처리시간 0.034초

Hydroxyzine Induces Cell Death in Triple-Negative Breast Cancer Cells via Mitochondrial Superoxide and Modulation of Jak2/STAT3 Signaling

  • Shakya, Rajina;Park, Gyu Hwan;Joo, Sang Hoon;Shim, Jung-Hyun;Choi, Joon-Seok
    • Biomolecules & Therapeutics
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    • 제30권6호
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    • pp.585-592
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    • 2022
  • Treatment of triple-negative breast cancer (TNBC) has been limited due to the lack of molecular targets. In this study, we evaluated the cytotoxicity of hydroxyzine, a histamine H1 receptor antagonist in human triple-negative breast cancer BT-20 and HCC-70 cells. Hydroxyzine inhibited the growth of cells in dose- and time-dependent manners. The annexin V/propidium iodide double staining assay showed that hydroxyzine induced apoptosis. The hydroxyzine-induced apoptosis was accompanied down-regulation of cyclins and CDKs, as well as the generation of reactive oxygen species (ROS) without cell cycle arrest. The effect of hydroxyzine on the induction of ROS and apoptosis on TNBC cells was prevented by pre-treatment with ROS scavengers, N-acetyl cysteine or Mito-TEMPO, a mitochondria-targeted antioxidant, indicating that an increase in the generation of ROS mediated the apoptosis induced by hydroxyzine. Western blot analysis showed that hydroxyzine-induced apoptosis was through down-regulation of the phosphorylation of JAK2 and STAT3 by hydroxyzine treatment. In addition, hydroxyzine induced the phosphorylation of JNK and p38 MAPK. Our results indicate that hydroxyzine induced apoptosis via mitochondrial superoxide generation and the suppression of JAK2/STAT3 signaling.

Isoegomaketone Ameliorates Atopic Dermatitis via MAPK and STAT Pathway-based Pro-Inflammatory Cytokine Regulation

  • ChangHyun Jin;Ye-Ram Kim;JaeYoung Shin;ByoungOk Cho;Ah-Reum Han
    • 방사선산업학회지
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    • 제17권4호
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    • pp.489-499
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    • 2023
  • Isoegomaketone(IK), isolated from the radiation-induced mutant cultivar of Perilla frutescens var. crispa, is a major phytochemical compound that has attracted attention in pharmacological research. In this study, we demonstrated that IK exerts anti-inflammatory and protective effects on human mast cells and in an atopic dermatitis mouse model. IK inhibited tumor necrosis factor-α(TNF-α), interleukin-6 (IL-6), and IL-8 expression in human mast cells (HMC-1) stimulated with phorbol myristate acetate(PMA) and calcium ionophore A23187 (PMACI). IK significantly reduced the PMACI-induced phosphorylation of ERK and JNK, but not p38. IK also inhibited the PMACI-induced phosphorylation of STAT1 and STAT3. Oral administration of IK in atopic dermatitis mouse model ameliorated skin inflammation severity, as measured by skin thickness and pro-inflammatory cytokine levels such as TNF-α, IL-8, IL-4, and IL-13. These results might suggest that IK is a potent therapeutic agent against skin inflammation and atopic dermatitis.

Janus Kinase 2 Inhibitor AG490 Inhibits the STAT3 Signaling Pathway by Suppressing Protein Translation of gp130

  • Seo, In-Ae;Lee, Hyun-Kyoung;Shin, Yoon-Kyung;Lee, Sang-Hwa;Seo, Su-Yeong;Park, Ji-Wook;Park, Hwan-Tae
    • The Korean Journal of Physiology and Pharmacology
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    • 제13권2호
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    • pp.131-138
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    • 2009
  • The binding of interleukin-6 (IL-6) cytokine family ligands to the gp130 receptor complex activates the Janus kinase (JAK)/ signal transducer and activator of transcription 3 (STAT3) signal transduction pathway, where STA T3 plays an important role in cell survival and tumorigenesis. Constitutive activation of STAT3 has been frequently observed in many cancer tissues, and thus, blocking of the gp130 signaling pathway, at the JAK level, might be a useful therapeutic approach for the suppression of STAT3 activity, as anticancer therapy. AG490 is a tyrphostin tyrosine kinase inhibitor that has been extensively used for inhibiting JAK2 in vitro and in vivo. In this study, we demonstrate a novel mechanism associated with AG490 that inhibits the JAK/STAT3 pathway. AG490 induced downregulation of gp130, a common receptor for the IL-6 cytokine family compounds, but not JAK2 or STAT3, within three hours of exposure. The downregulation of gp130 was not caused by enhanced degradation of gp130 or by inhibition of mRNA transcription. It most likely occurred by translation inhibition of gp130 in association with phosphorylation of the eukaryotic initiation factor-2 a. The inhibition of protein synthesis of gp130 by AG490 led to immediate loss of mature gp130 in cell membranes, due to its short half-life, thereby resulting in reduction in the STAT3 response to IL-6. Taken together, these results suggest that AG490 blocks the STAT3 activation pathway via a novel pathway.

Curcumin suppresses the production of interleukin-6 in Prevotella intermedia lipopolysaccharide-activated RAW 264.7 cells

  • Kim, Sung-Jo
    • Journal of Periodontal and Implant Science
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    • 제41권3호
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    • pp.157-163
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    • 2011
  • Purpose: Curcumin is known to exert numerous biological effects including anti-inflammatory activity. In this study, we investigated the effects of curcumin on the production of interleukin-6 (IL-6) by murine macrophage-like RAW 264.7 cells stimulated with lipopolysaccharide (LPS) from Prevotella intermedia, a major cause of inflammatory periodontal disease, and sought to determine the underlying mechanisms of action. Methods: LPS was prepared from lyophilized P. intermedia ATCC 25611 cells by the standard hot phenol-water method. Culture supernatants were collected and assayed for IL-6. We used real-time polymerase chain reaction to detect IL-6 mRNA expression. $I{\kappa}B-{\alpha}$ degradation, nuclear translocation of NF-${\kappa}B$ subunits, and STAT1 phosphorylation were characterized via immunoblotting. DNA-binding of NF-${\kappa}B$ was also analyzed. Results: Curcumin strongly suppressed the production of IL-6 at both gene transcription and translation levels in P. intermedia LPS-activated RAW 264.7 cells. Curcumin did not inhibit the degradation of $I{\kappa}B-{\alpha}$ induced by P. intermedia LPS. Curcumin blocked NF-${\kappa}B$ signaling through the inhibition of nuclear translocation of NF-${\kappa}B$ p50 subunit. Curcumin also attenuated DNA binding activity of p50 and p65 subunits and suppressed STAT1 phosphorylation. Conclusions: Although further study is required to explore the detailed mechanism of action, curcumin may contribute to blockade of the host-destructive processes mediated by IL-6 and appears to have potential therapeutic values in the treatment of inflammatory periodontal disease.

Gamma Irradiation-reduced IFN-γ Expression, STAT1 Signals, and Cell-mediated Immunity

  • Han, Seon-Kyu;Song, Jie-Young;Yun, Yeon-Sook;Yi, Seh-Yoon
    • BMB Reports
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    • 제35권6호
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    • pp.583-589
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    • 2002
  • The signal transducer and activator of transcription (STAT)1 is a cytoplasmic-transcription factor that is phosphorylated by Janus kinases (Jak) in response to interferon $\gamma$ (IFN-$\gamma$). The phosphorylated STAT1 translocates to the nucleus, where it turns on specific sets of IFN-$\gamma$-inducible genes, such as the interferon regulatory factor (IRF)-1. We show here that gamma irradiation reduces the IFN-$\gamma$ mRNA expression. The inhibition of the STAT1 phosphorylation and the IRF-1 expression by gamma irradiation was also observed. In contrast, the mRNA levels of IL-5 and transcription factor GATA-3 were slightly induced by gamma irradiation when compared to the non-irradiated sample. Furthermore, we detected the inhibition of cell-mediated immunity by gamma irradiation in the allogenic-mixed lymphocytes' reaction (MLR). These results postulate that gamma irradiation induces the polarized-Th2 response and interferes with STAT1 signals, thereby causing the immunosuppression of the Th1 response.

과산화수소 자극으로 활성화된 C6 성상교세포에 대한 맥문동추출물의 조절 효능 연구 (A Study on the Effect of Liriopis tuber water extract on Hydrogen Peroxide-stimulated C6 Astrocyte Cells)

  • 박기호;강석용;정효원;박용기
    • 대한본초학회지
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    • 제35권4호
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    • pp.9-16
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    • 2020
  • Objective : To identify the effects of the water extract of Liriope platyphylla tuber (Liriopis tuber, LT) on the activation of astocytes, we investigated the regulatory effects of LT extract on H2O2-induced oxidative damage in C6 rat astrocytes. Methods : LT extract was extracted with boiling water. C6 cell line were treated with LT extract at 1, 2, and 3 mg/㎖ or without for 30 min and then stimulated with H2O2 at 5 ㎛ for 24 hr. The cell viability was measured by MTT assay. The expression of glial fibrillary acidic protein (GFAP), signal transducer and activator of transcription 3 (STAT3), phospho-STAT3 (pSTAT3), cyclooxygenase (COX-2), Nuclear factor-κB (NF-κB), superoxide dismutase 2 (SOD2), heme oxygenase-1 (HO-1), catalase, Akt, phospho-Akt (p-Akt) phosphoinositide 3-kinases (PI3K), and protein kinase C alpha (PKCα) proteins were determined by Western blot, respectively. GFAP expression was also observed with immunocytochemistry under a fluorescence microscope. Results : LT extract induced cell proliferation in H2O2-stimulated C6 cells. LT extract significantly inhibited the expression of GFAP, NF-κB and COX-2 and increased the expression of HO-1 and the phosphorylation of STAT3 in H2O2-stimulated C6 cells. LT extract also significantly increased the phosphorylation of Akt and decreased the expression of PKCα in a dose-dependent manner in H2O2-stimulated C6 cells. Conclusions : LT extract can regulate H2O2-induced activation of astrocytes through inhibiting the expression of NF-κB, COX-2 and regulating Akt / HO-1, STAT3 or PKCα signaling pathway.

당지질로 유도한 염증반응에서 Piceatannol의 항염증 기전 연구 (Mechanism Underlying the Anti-Inflammatory Action of Piceatannol Induced by Lipopolysaccharide)

  • 조한진;심재훈;소홍섭;윤정한
    • 한국식품영양과학회지
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    • 제41권9호
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    • pp.1226-1234
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    • 2012
  • 본 연구에서는 염증반응을 조절하는 다양한 신호전달체계를 중심으로 분자생물학적 방법을 통해 piceatannol의 항염증 기전을 규명하였다. LPS로 염증반응을 유도한 Raw 264.7 대식세포에서 piceatannol은 iNOS의 발현 억제를 통해 NO의 생성을 감소시키고 염증성 사이토카인(TNF-${\alpha}$, IL-6, IL-$1{\beta}$)의 생성을 감소시켰다. 염증반응을 조절하는 신호전달체계 중 piceatannol은 LPS에 의해 유도된 $I{\kappa}B$의 분해와 p65의 핵으로의 이동을 억제하고, LPS에 의해 유도된 SAPK/JNK의 인산화를 억제하였다. 또한 piceatannol은 LPS와 IL-6(LPS에 의해 증가됨)에 의한 STAT3의 활성화를 억제하였다. 뿐만 아니라 piceatannol은 Nrf2의 핵 내 축적을 야기하고 ARE의 transcriptional activity를 증가시켜 HO-1의 발현을 증가시켰다. 본 연구의 결과, piceatannol은 NF-${\kappa}B$와 AP-1, STAT3 신호전달의 억제를 통해, 그리고 HO-1의 발현 증가를 통해 항염증 효과를 나타내었다(Fig. 8).

전립선 암세포에서 delphinidin에 의한 HIF-1α와 STAT3 억제를 통한 혈관내피 성장 인자 발현 저해 효과 (Delphinidin Suppresses Angiogenesis via the Inhibition of HIF-1α and STAT3 Expressions in PC3M Cells)

  • 김문현;김미현;박영자;장영채;박윤엽;송현욱
    • 한국식품과학회지
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    • 제48권1호
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    • pp.66-71
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    • 2016
  • 델피니딘은 양전하를 뛰는 diphenylpropane의 polyphenolic ring 구조를 가진 주요한 안토시아닌 색소 중에 하나이다. 최근 연구에서 델피니딘은 항산화, 항염증 뿐만 아니라 항암 효능을 가진다고 보고되었다. 본 연구에서는 전립샘 암에서 종양의 성장과 신생혈관생성에 관련된 중요한 인자인 VEGF 발현에 대한 델피니딘의 억제 효과를 조사하였다. RT-PCR을 통해 델피니딘을 처리한 PC3M 전립샘 암세포 세포에서 EGF로 유도한 VEGF mRNA 발현 수준이 감소됨을 확인하였다. 또한 델피니딘은 VEGF의 전사인자인 HIF-$1{\alpha}$와 STAT3가 세포 핵으로 전위되는 것을 효과적으로 억제하였다. 한편 luciferase assay을 통해 HRE-promoter 활성을 확인해 본 결과, 델피니딘이 HIF-$1{\alpha}$의 전사 활성을 억제시켜 VEGF 발현을 감소시키는 것을 알 수 있었다. 그리고 델피니딘은 EGFR의 발현에는 영향을 미치지 않고, Akt, p70S6K, 4EBP1의 인산화를 특이적으로 억제하는 것으로 나타났다. 결론적으로 델피니딘이 HIF-$1{\alpha}$와 STAT3, VEGF 발현을 억제를 통하여 암세포 증식억제와 신생혈관형성을 억제하는 역할을 새롭게 확인하였다.

Methyl 9-Oxo-(10E,12E)-octadecadienoate Isolated from Fomes fomentarius Attenuates Lipopolysaccharide-Induced Inflammatory Response by Blocking Phosphorylation of STAT3 in Murine Macrophages

  • Choe, Ji-Hyun;Yi, Young-Joo;Lee, Myeong-Seok;Seo, Dong-Won;Yun, Bong-Sik;Lee, Sang-Myeong
    • Mycobiology
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    • 제43권3호
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    • pp.319-326
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    • 2015
  • Fomes fomentarius is a fungus of the Polyporaceae family and is used in traditional oriental therapies. Although the anti-inflammatory activities of this species have been previously reported, the identity of the bioactive compounds responsible for this activity remains unknown. Here, we investigated whether methyl 9-oxo-(10E,12E)-octadecadienoate (FF-8) purified from F. fomentarius exerts anti-inflammatory activity in murine macrophages stimulated with lipopolysaccharide (LPS). FF-8 suppressed secretion of nitric oxide (NO) and prostaglandin $E_2$ through downregulation of inducible NO synthase and cyclooxygenase-2 expression induced by LPS. In addition, pretreatment of cells with FF-8 led to a reduction in levels of secreted inflammatory cytokines such as tumor necrosis factor-${\alpha}$ and interleukin-6 in macrophages stimulated with LPS. Conversely, FF-8 did not affect nuclear factor ${\kappa}B$, p38, c-Jun NH2-terminal kinase, and extracellular signal-regulated kinase pathways. Instead, FF-8 specifically interfered with signal transducer and activator of transcription 3 (STAT3) phosphorylation induced by LPS. Collectively, this study demonstrated that FF-8 purified from F. fomentarius suppresses inflammatory responses in macrophages stimulated with LPS by inhibiting STAT3 activation. Further studies will be required to elucidate the anti-inflammatory effect of FF-8 in vivo.

1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol (EC-18) Modulates Th2 Immunity through Attenuation of IL-4 Expression

  • Yoon, Sun Young;Kang, Ho Bum;Ko, Young-Eun;Shin, Su-Hyun;Kim, Young-Jun;Sohn, Ki-Young;Han, Yong-Hae;Chong, Saeho;Kim, Jae Wha
    • IMMUNE NETWORK
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    • 제15권2호
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    • pp.100-109
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    • 2015
  • Controlling balance between T-helper type 1 (Th1) and T-helper type 2 (Th2) plays a pivotal role in maintaining the biological rhythm of Th1/Th2 and circumventing diseases caused by Th1/Th2 imbalance. Interleukin 4 (IL-4) is a Th2-type cytokine and often associated with hypersensitivity-related diseases such as atopic dermatitis and allergies when overexpressed. In this study, we have tried to elucidate the function of 1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol (EC-18) as an essential modulator of Th1/Th2 balance. EC-18 has showed an inhibitory effect on the production of IL-4 in a dose-dependent manner. RT-PCR analysis has proved EC-18 affect the transcription of IL-4. By analyzing the phosphorylation status of Signal transducer and activator of transcription 6 (STAT6), which is a transcriptional activator of IL-4 expression, we discovered that EC-18 induced the decrease of STAT6 activity in several stimulated cell lines, which was also showed in STAT6 reporter analysis. Co-treatment of EC-18 significantly weakened atopy-like phenotypes in mice treated with an allergen. Collectively, our results suggest that EC-18 is a potent Th2 modulating factor by regulating the transcription of IL-4 via STAT6 modulation, and could be developed for immune-modulatory therapeutics.