• Title/Summary/Keyword: Stat1

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Tyrphostin ErbB2 Inhibitors AG825 and AG879 Have Non-specific Suppressive Effects on gp130/ STAT3 Signaling

  • Lee, Hyun-Kyoung;Seo, In-Ae;Lee, Sang-Hwa;Seo, Su-Young;Kim, Kyung-Sup;Park, Hwan-Tae
    • The Korean Journal of Physiology and Pharmacology
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    • v.12 no.5
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    • pp.281-286
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    • 2008
  • Although the interaction between gp130 and the ErbB family has frequently been shown in cancer cells, the mechanism of this interaction remains unclear and controversial. In the present study, we found that specific tyrphostin inhibitors of ErbB2 (AG825 and AG879), but not ErbB1 inhibitor (AG1478), suppressed IL-6-induced tyrosine phosphorylation of STAT3 in schwannoma cells. However, biochemical evidence for transactivation of ErbB2 by IL-6 was not observed. Additionally, the inhibition of ErbB2 expression, with either a specific RNAi or transfection of an ErbB2 mutant lacking the intracellular domain did not inhibit the IL-6-induced tyrosine phosphorylation of STAT3. Thus, it seems that tyrphostins, which are known as specific inhibitors of the ErbB2 kinase, may have non-specific suppressive effects on the IL-6/STAT3 pathway.

Ceramium boydenii, a Red Alga, Inhibits MDC/CCL22 Production Via Suppression of STAT1 Activation in HaCaT Keratinocyte (HaCaT 각질형성세포에서 홍조류인 단박(Ceramium boydenii)의 STAT1 활성 억제를 통한 MDC/CCL22 생성 억제 효과)

  • Kang, Na-Jin;Kang, Gyeung-Jin;Han, Sang-Chul;Hyun, Eun-A;Koo, Dong-Hwan;Koh, Young-Sang;Ko, Mi-Hee;Hyun, Jin Won;Kang, Hee-Kyoung;Yoo, Eun-Sook
    • Korean Journal of Pharmacognosy
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    • v.44 no.2
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    • pp.154-160
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    • 2013
  • Ceramium boydenii belongs to euphorbia humitusa of red algae, and is distributed along the coast of Jeju island. This study was conducted to examine the anti-inflammatory effect and action mechanism of C. boydenii in the human keratinocyte cell line HaCaT. The 80% EtOH extract of C. boydenii inhibits the production of MDC (macrophage derived chemokine), an inflammatory chemokine, induced by IFN-${\gamma}$ and TNF-${\alpha}$ in a concentration dependent manner. It also suppressed the phosphorylation and nuclear translocation of STAT1, a key transcription factor in IFN-${\gamma}$ and TNF-${\alpha}$ signaling pathway, at the effective concentrations. These results suggest that C. boydenii demonstrates the anti-inflammatory activity via the suppression of STAT1 activation and has the significant value as an anti-inflammatory source.

Enhancing effect of Canavalia gladiata DC semen on the hematopoietic expansion and function of stem cells (도두(刀豆)의 조혈증진 작용에 관한 연구)

  • Kim, Seung-Hyung;Kim, Kun-Hoae;Chi, Gyeong-Yup;Cho, In-Sik;Kim, Han-Young;Lee, Young-Cheol
    • The Korea Journal of Herbology
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    • v.27 no.4
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    • pp.9-16
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    • 2012
  • Objective : Canavalia gladiata DC semen (CGS) have been used to improve hematopoietic activity. In the current study, we investigated whether CGS regulate hemato-potentiating function using hematopoietic stem cells (HSCs) as a testing system. Methods : HSCs isolated from femur in mice with leukopenia and thrombocytopenia induced induced by CTX. Then, Real-time PCR was performed to measure the mRNA expression and hematopoietic related gene (EPO, IL-3, SCF, c-kit, GM-CSF), the phoaphorylation of GATA-1 and STAT-5a/b were observed by ELISA method, and the number of granulocyte erythrocyte monocyte macrophage colony-forming units (CFU-GEMM) and erythroid burst forming units (BFU-E), semisolid clonogenic assay was performed. Result : When HSCs were treated with CGS, the expression of hematopoietic related genes (EPO, IL-3, SCF, c-kit, and GM-CSF) were significantly increased at the levels of mRNA as well as production in HSCs. Additionally, CGS enhanced phosphorylation of STAT-1 and signal transducer and activator of transcription-5a/b (STAT-5a/b) in HSCs. Furthermore, CGS significantly enhanced the growth rate of granulocyte erythrocyte monocyte macrophage colony-forming units (CFU-GEMM) and erythroid burst forming units (BFU-E) in vitro. Conclusion : These result suggest that CGS has hematopoietic enhancement via hematopoietic cytokine-mediated GATA-1/STAT-5a/b pathway.

Studies on the regulation of Hematopoietic enhancement of Brassica campestris var narinosa., Canavalia gladiata DC semen and their combinational prescription via Jak2/STAT5/GATA1 Pathway in Sca-1+ hematopoietic stem cells (Sca-1+골수조혈세포에서 JAK2/STAT5/GATA-1 신호전달 경로를 통한 다채, 도두 그리고 두 조합물에 의한 조혈증진 조절에 관한 연구)

  • Kim, Kunhoae;Kim, Seung-Hyung;Cho, In-Sik;Kim, Han-Young;Kim, Dong-Seon;Lee, Young-Cheol
    • The Korea Journal of Herbology
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    • v.28 no.4
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    • pp.7-16
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    • 2013
  • Objectives : Brassica campestris var narinosa (BCN), Canavalia gladiata DC semen (CGD) and their combinational prescription (BCN+CGD) have been use to demonstrate to regulate hematopoiesis. In the current study, we investigated whether Brassica campestris var narinosa, Canavalia gladiata DC semen and their combinational prescription is related to hemato-potentiating function using Sca-$1^+$ hematopoietic stem cells (Sca-$1^+HSCs$) as a testing system. Methods : Sca-$1^+HSCs$ isolated from femur in C57bl/6 mice with leukopenia and thrombocytopenia induced by cyclophosphamide (CTX). Then, Real-time PCR was performed to measure the mRNA expression, ELISA and haematopoiesis-related gene (EPO, TPO, IL-3, SCF, c-kit, GM-CSF), the phosphorylation of JAK2, GATA-1 and STAT-5a/b were observed by western blot, and the numbers of $CD117^+/Sca-1^+$ cell and the number of granulocyte erythrocyte monocyte macrophage colony-forming units (CFU-GEMM) and erythroid burst forming units (BFU-E), semisolid clonogenic assay was performed. Result : When Sca-$1^+HSCs$ were treated with Brassica campestris var narinosa, Canavalia gladiata DC semen and their combinational prescription with rIL-3/rSCF, the expression of haematopoiesis-related (EPO, TPO, IL-3, SCF, c-kit, and GM-CSF) were significantly increased at the levels of mRNA as well as production in Sca-$1^+HSCs$. Additionally, CGS enhanced phosphorylation of JAK2, GATA-1, and signal transducer and activator of transcription-5a/b (STAT-5a/b) in Sca-$1^+HSCs$. Furthermore, their combinational prescription (BCN+CGD) significantly enhanced the growth rate of granulocyte erythrocyte monocyte macrophage colony-forming units (CFU-GEMM) and erythroid burst forming units (BFU-E) in vitro. Conclusion : These result suggest that Brassica campestris var narinosa (BCN) and Canavalia gladiata DC have hematopoietic enhancement via hematopoietic cytokine-mediated JAK2/GATA-1/STAT-5a/b pathway, and their combinational prescription (BCN+CGD) has superior hematopoietic enhancement to those of individual extracts.

The Effects of Injinchunggantang on Interferon Signaling Pathway of HepG2 Cells (인진청간탕(茵蔯淸肝湯)이 HepG2 cell의 인터페론 신호전달계에 미치는 영향)

  • Yi, Jong-Hoon;Kim, Young-Chul;Lee, Jang-Hoon;Woo, Hong-Jung
    • The Journal of Internal Korean Medicine
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    • v.26 no.1
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    • pp.74-92
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    • 2005
  • Objectives/Methods : To analyze the effect of Injinchunggantang(IJCGT) to Interferon-${\alpha}/{\beta}$ signal transmission system in HepG2 cells, HepG2 Cell were treated with IJCGT. Also, revelation of MxA, 2'5'-OAS mRNA leaded by Interferon-${\alpha}/{\beta}$ and revelation and activation of Jak1, TYK1, and STAT 1, all main signal transmission factors, were analyzed. Results : The analysis resulted in the following 1. With interferon ${\alpha}/{\beta}$ there was no affect cell propagation of Hep G2 cells. With IJCGT alone, cell propagation of HepG2 was promoted, and cell propagation control function was recovered. 2. With interferon ${\alpha}/{\beta}$ cell death was unaffected. With IJCGT apoptosis of HepG2 cell was restrained, and the cell's reaction to interferon was unaffected. 3. With interferon ${\alpha}/{\beta}$ treatment mRNA revelation of MxA and 2'5'-OAS was induced. When HepG2 cells were injected with IJCGT without interferon ${\alpha}/{\beta}$ treatment, mRNA revelation of MxA and 2'5'-OAS increased in proportion to the treatment density. With pre-treatment of IJCGT, leaded with interferon ${\alpha}/{\beta}$, promoted revelation of MxA, 2'5' -OAS mRNA. 4. Though mRNA revelation of lakl, TYK1 and STAT1 was unaffected with IJCGT, activation of STAT1 was promoted with an increase of phosphorylation of STAT1 protein. With pre-treatment of IJCGT, Jak1, TYK2, STAT1 phosphorylation, leaded with interferon, strengthened. 5. TNF-a, IL-1b and LPS present, revelation of MxA and 2'5'-OAS mRNA leaded by interferon was restrained when HepG2 cells were treated with IJCGT, and the interferon signal transmission system restraint action leaded by inflammatory cytokines was moderated. Conclusion : These results support a role for IJGCT in promotion of anti-virus action through maintainance of the liver's sensibility toward interferon. A clinical study of an interferon treated patient treated also with IJGCT is needed to determine its efficacy.

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Prunus Yedoensis Inhibits the Inflammatory Chemokines, MDC and TARC, by Regulating the STAT1-Signaling Pathway in IFN-γ-stimulated HaCaT Human Keratinocytes

  • Kang, Gyeoung-Jin;Lee, Hye-Ja;Yoon, Weon-Jong;Yang, Eun-Jin;Park, Sun-Son;Kang, Hee-Kyoung;Park, Myung-Hwan;Yoo, Eun-Sook
    • Biomolecules & Therapeutics
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    • v.16 no.4
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    • pp.394-402
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    • 2008
  • Atopic dermatitis (AD) is an inflammatory skin disease commonly characterized by infiltration of inflammatory cells into skin lesions. Keratinocytes produce many chemokines that are involved in the pathogenesis of skin disorders. In particular, macrophage-derived chemokine (MDC/CCL22) and thymus and activationregulated chemokine (TARC/CCL17) are Th2-type cytokines. Serum MDC and TARC levels are increased in AD patients. In this study, we investigated the anti-inflammatory effect and mechanism of action of the active fraction from Prunus yedoensis bark. We evaluated their inhibitory effects on the AD-like inflammatory markers (MDC and TARC) and JAK-STAT pathway (STAT1) in HaCaT keratinocytes. The EtOAc fraction of the crude extract (80% EtOH) and the E5 sub-fraction potently inhibited the induction of MDC and TARC mRNA and protein at 50 ${\mu}g$/mL in HaCaT cells. In addition, the E5 sub-fraction inhibited the phosphorylation of STAT1 protein associated with IFN-$\gamma$ signaling transduction in a dose-dependent manner. Thus, P. yedoensis may have antiatopic activity by suppressing the inflammatory chemokines (MDC and TARC).

Histone Deacetylation Is Involved in Activation of CXCL10 Upon IFNγ Stimulation

  • Guo, Jin-Jun;Li, Qing-ling;Zhang, Jun;Huang, Ai-Long
    • Molecules and Cells
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    • v.22 no.2
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    • pp.163-167
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    • 2006
  • Histone deacetylase (HDAC) activity is commonly associated with transcriptional repression. However, there is also evidence for a function in transcriptional activation. Previous studies have demonstrated a fundamental role of deacetylase activity in $IFN{\alpha}$-responsive gene transcription. In the case of type II IFN ($IFN{\gamma}$) results are controversial: some genes require HDAC activity, while transcription of others is repressed by HDAC. To investigate the effect of HDAC on transcription of an $IFN{\gamma}$-activated gene, real-time PCR was used to measure CXCL10 mRNA in Hela cells stimulated with $IFN{\gamma}$ in the presence or absence of the HDAC inhibitor TSA. Chromatin imunoprecipitation combined with real-time PCR was used to check acetylation of histone H4 and recruitment of the STAT1 complex to the ISRE locus of the CXCL10 gene. Activation of CXCL10 transcription in response to $IFN{\gamma}$ was paralleled by a decrease in histone H4 acetylation and an increase in recruitment of the STAT1 complex to the CXCL10 ISRE locus. The transcription of CXCL10 and histone H4 deacetylation were blocked by TSA, but the latter had no obvious affect on recruitment of the STAT1 complex. Our data indicate that $IFN{\gamma}$ and STAT-dependent gene transcription requires the participation of HDAC, as does the $IFN{\alpha}$-STAT pathway.

Hwanggeumchal Sorghum Extracts Suppresses Tumor Growth via Inhibitions of IGF-1R, STAT Family and Jak/STAT Signaling Expression for Human MDA-MB 231 Breast Cancer Cells (인간 유방암세포 MDA-MB 231에 대한 황금찰수수 추출물의 IGF-1R, STAT Family, Jak/STAT Signaling 발현의 억제를 통한 종양 성장의 억제 효과 연구)

  • Park, Jin-Hee;Yeo, Min-A;Kim, Sun-Jin;Kwon, Jung-Woong;Song, Sung-Hyun;Yong, Soo-Jung;Jang, Mi-So;Kim, Myong-Jo;Park, Dong-Sik;Song, Hong-Keun;Ahn, Jong-Guk;Yang, Young-Mok;Chung, Ill-Min
    • 한국약용작물학회:학술대회논문집
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    • 2010.10a
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    • pp.495-496
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    • 2010
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Porphyromonas gingivalis lipopolysaccharide stimulates vascular smooth muscle cell migration through signal transducer and activator of transcription 3-mediated matrix metalloproteinase-9 expression

  • Kim, Yeon;Park, Joo-Yeon;Park, Hyun-Joo;Kim, Mi-Kyoung;Kim, Yong-Il;Bae, Soo-Kyung;Kim, Hyung Joon;Bae, Moon-Kyoung
    • International Journal of Oral Biology
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    • v.44 no.1
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    • pp.20-26
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    • 2019
  • Periodontal diseases have been associated with the development of cardiovascular diseases. Accumulating evidences have indicated that Porphyromonas gingivalis, a major periodontopathic pathogen, plays a critical role in the pathogenesis of atherosclerosis. In the present study, we demonstrated that P. gingivalis lipopolysaccharide (LPS) increases the mRNA and protein expression of matrix metalloproteinase-9 (MMP-9) in rat vascular smooth muscle cells. We showed that the MMP-9 expression induced by P. gingivalis LPS is mediated by the activation of signal transducer and activator of transcription 3 (STAT3) in vascular smooth muscle cells. Furthermore, the inhibition of STAT3 activity reduced P. gingivalis LPS-induced migration of vascular smooth muscle cells. Overall, our findings indicate that P. gingivalis LPS stimulates the migration of vascular smooth muscle cells via STAT3-mediated MMP-9 expression.

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

  • Cho, Han-Jin;Shim, Jae-Hoon;So, Hong-Seob;YoonPark, Jung-Han
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.41 no.9
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    • pp.1226-1234
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    • 2012
  • 3,4,3',5'-Tetrahydroxy-trans-stilbene (piceatannol) is a derivative of resveratrol with a variety of biological activities, including anti-inflammatory, anti-proliferative, and anti-cancer activities. We assessed the mechanisms by which piceatannol inhibits inflammatory responses using lipopolysaccharide (LPS)-treated Raw264.7 murine macrophages. Piceatannol (0~10 ${\mu}mol/L$) decreased LPS-induced release of nitric oxide, tumor necrosis factor (TNF)-${\alpha}$, interleukin (IL)-6, IL-$1{\beta}$, and inhibited LPS-induced protein expression of inducible nitric oxide synthase (iNOS). Activation of nuclear factor-kappaB (NF-${\kappa}B$), activator protein (AP)-1, and signal transducer and activator of transcription 3 (STAT3) are crucial steps during an inflammatory response. Piceatannol prevented LPS-induced degradation of inhibitor of ${\kappa}B$ ($I{\kappa}B$), translocation of p65 to the nucleus, and phosphorylation of stress-activated protein kinase/c-Jun NH2-terminal kinase (SAPK/JNK). Additionally, piceatannol inhibited LPS-induced phosphorylation of STAT3 and IL-6-induced translocation of STAT3 to the nucleus. Furthermore, piceatannol increased the protein and mRNA levels of hemeoxygenase (HO)-1, the rate-limiting enzyme of heme catabolism that plays a critical role in mediating antioxidant and anti-inflammatory effects. Piceatannol further induced antioxidant response elements (ARE)-driven luciferase activity in Raw264.7 cells transfected with an ARE-luciferase reporter construct containing the enhancer 2 and minimal promoter region of HO-1. These results suggest that piceatannol exerts anti-inflammatory effects via the down-regulation of iNOS expression and up-regulation of HO-1 expression.