• Title/Summary/Keyword: Downregulation

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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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    • v.43 no.3
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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.

Differential Modulation of Lipopolysaccharide-Induced Inflammatory Cytokine Production by and Antioxidant Activity of Fomentariol in RAW264.7 Cells

  • Seo, Dong-Won;Yi, Young-Joo;Lee, Myeong-Seok;Yun, Bong-Sik;Lee, Sang-Myeong
    • Mycobiology
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    • v.43 no.4
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    • pp.450-457
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    • 2015
  • Medicinal mushrooms have been used worldwide to treat cancer and modulate the immune system. Over the last several years, there has been increasing interest in isolating bioactive compounds from medicinal mushrooms and evaluating their health beneficial effects. Fomes fomentarius is used in traditional oriental medicine and is known to possess antioxidant, antiinflammatory, antidiabetic, and antitumor effects. In the present study, we isolated fomentariol from Fomes fomentarius and investigated its anti-inflammatory effect in murine macrophages (RAW264.7 cells) stimulated with lipopolysaccharides. Fomentariol inhibited the production of nitric oxide and intracellular reactive oxygen species triggered by lipopolysaccharides. Interestingly, fomentariol differentially regulated cytokine production triggered by lipopolysaccharides. Fomentariol effectively suppressed the production of interleukin-$1{\beta}$ and interleukin-6 but not tumor necrosis factor-${\alpha}$. The inhibitory effect of fomentariol against nitric oxide, interleukin-$1{\beta}$, and interleukin-6 production was possibly mediated by downregulation of the extracellular signal-regulated kinase signaling pathway. Taken together, our results suggest that fomentariol differentially modulated inflammatory responses triggered by lipopolysaccharides in macrophages and is one of the bioactive compounds that mediate the physiological effects of Fomes fomentarius.

Protective Effect of Gardenia jasminoides Against Carbon Tetrachloride-Induced Acute Hepatotoxicity (사염화탄소 유도 급성 간독성 모델에서 치자의 간 보호 효과)

  • Shin, Jun-Kyu;Kim, Hyo-Yeon;Lee, Sun-Mee
    • YAKHAK HOEJI
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    • v.54 no.1
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    • pp.55-61
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    • 2010
  • Gardenia jasminoides is one of the most widely used herbal preparations for the treatment of liver disorders. This study evaluated the potential beneficial effect of G. jasminoides in a mouse model of carbon tetrachloride ($CCl_4$)-induced liver injury. The mice were treated intraperitoneally with $CCl_4$ (10 ${\mu}l$/kg). They received G. jasminoides (30, 100, 300 mg/kg) 48 h, 24 h and 2 h before and 6 h after administering $CCl_4$. The serum activities of aminotransferase and the hepatic level of malondialdehyde were significantly higher 24 h after the $CCl_4$ treatment, while the concentration of reduced glutathione was lower. These changes were attenuated by G. jasminoides. $CCl_4$ increased the level of circulating tumor necrosis factor-$\alpha$ (TNF-$\alpha$) markedly, which was reduced by G. jasminoides. The levels of hepatic inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein expression were markedly higher after the $CCl_4$ treatment. G. jasminoides diminished these alterations. $CCl_4$ increased the level of TNF-$\alpha$, iNOS and COX-2 mRNA expressions, and these increases were attenuated by G. jasminoides. These results suggest that G. jasminoides alleviates $CCl_4$-induced liver injury, and this protection is likely due to the reduced oxidative stress and the downregulation of proinflammatory mediators.

BMP-2-Enhanced Chondrogenesis Involves p38 MAPK-mediated Down-Regulation of Wnt-7a Pathway

  • Jin, Eun-Jung;Lee, Sun-Young;Choi, Young-Ae;Jung, Jae-Chang;Bang, Ok-Sun;Kang, Shin-Sung
    • Molecules and Cells
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    • v.22 no.3
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    • pp.353-359
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    • 2006
  • The bone morphogenetic protein (BMP) family has been implicated in control of cartilage development. Here, we demonstrate that BMP-2 promotes chondrogenesis by activating p38 mitogen-activated protein kinase (MAPK), which in turn downregulates $Wnt-7a/{\beta}$-catenin signaling responsible for proteasomal degradation of Sox9. Exposure of mesenchymal cells to BMP-2 resulted in upregulation of Sox9 protein and a concomitant decrease in the level of ${\beta}$-catenin protein and Wnt-7a signaling. In agreement with this, the interaction of Sox9 with ${\beta}$-catenin was inhibited in the presence of BMP-2. Inhibition of the p38 MAPK pathway using a dominant negative mutant led to sustained Wnt-7a signaling and decreased Sox9 expression, with consequent inhibition of precartilage condensation and chondrogenic differentiation. Moreover, overexpression of ${\beta}$-catenin caused degradation of Sox9 via the ubiquitin/26S proteasome pathway. Our results collectively indicate that the increase in Sox9 protein resulting from downregulation of ${\beta}$-catenin/Wnt-7a signaling is mediated by p38 MAPK during BMP-2 induced chondrogenesis in chick wing bud mesenchymal cells.

PPARα-Target Gene Expression Requires TIS21/BTG2 Gene in Liver of the C57BL/6 Mice under Fasting Condition

  • Hong, Allen Eugene;Ryu, Min Sook;Kim, Seung Jun;Hwang, Seung Yong;Lim, In Kyoung
    • Molecules and Cells
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    • v.41 no.2
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    • pp.140-149
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    • 2018
  • The $TIS21^{/BTG2/PC3}$ gene belongs to the antiproliferative gene (APRO) family and exhibits tumor suppressive activity. However, here we report that TIS21 controls lipid metabolism, rather than cell proliferation, under fasting condition. Using microarray analysis, whole gene expression changes were investigated in liver of TIS21 knockout (TIS21-KO) mice after 20 h fasting and compared with wild type (WT). Peroxisome proliferator-activated receptor alpha ($PPAR{\alpha}$) target gene expression was almost absent in contrast to increased lipid synthesis in the TIS21-KO mice compared to WT mice. Immunohistochemistry with hematoxylin and eosin staining revealed that lipid deposition was focal in the TIS21-KO liver as opposed to the diffuse and homogeneous pattern in the WT liver after 24 h starvation. In addition, cathepsin E expression was over 10 times higher in the TIS21-KO liver than that in the WT, as opposed to the significant reduction of thioltransferase in both adult and fetal livers. At present, we cannot account for the role of cathepsin E. However, downregulation of glutaredoxin 2 thioltransferase expression might affect hypoxic damage in the TIS21-KO liver. We suggest that the $TIS21^{/BTG2}$ gene might be essential to maintain energy metabolism and reducing power in the liver under fasting condition.

MiR-199a/b-5p Inhibits Lymphangiogenesis by Targeting Discoidin Domain Receptor 1 in Corneal Injury

  • Oh, Sooeun;Seo, Minkoo;Choi, Jun-Sub;Joo, Choun-Ki;Lee, Suk Kyeong
    • Molecules and Cells
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    • v.41 no.2
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    • pp.93-102
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    • 2018
  • Discoidin domain receptor 1 (DDR1) is involved in tumorigenesis and angiogenesis. However, its role in lymphangiogenesis has been unknown. Here, we tested whether downregulation of DDR1 expression by miR-199a/b can suppress lymphangiogenesis. We also aimed to identify miRNA target site(s) in the 3' untranslated region (UTR) of DDR1. Transfection with miR-199a/b-5p mimics reduced expression of DDR1 and tube formation in primary human dermal lymphatic endothelial cells, whereas miR-199a/b-5p inhibitors showed the opposite effects. Critically, injection of miR-199a/b-5p mimics suppressed DDR1 expression and lymphangiogenesis in a corneal alkali-burn rat model. The three well-conserved seed matched sites for miR-199a/b-5p in the DDR1 3'-UTR were targeted, and miRNA binding to at least two sites was required for DDR1 inhibition. Our data suggest that DDR1 promotes enhanced lymphangiogenesis during eye injury, and miR-199a/b-5p suppresses this activity by inhibiting DDR1 expression. Thus, this miRNA may be useful for the treatment of lymphangiogenesis-related eye diseases.

Capsosiphon Fulvescens Decreases Melanin Synthesis Via Downregulation of Tyrosinase and TRP-2 Expression

  • Yoo, Hyun-Ju;Jo, Mi-Gyeong;Park, Si-Jun;Mun, Yeun-Ja;Pyo, Hyeong-Bae;Lim, Kyu-Sang;Lee, Ki-Nam;Woo, Won-Hong
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.21 no.4
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    • pp.998-1003
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    • 2007
  • The green marine algae, Capsosiphon fulvescens (CF) is a food supplement cultivated in south coast of Southern Korea. The purpose of this study was to investigate the mechanism of CF-induced hypopigmentation. The present study was designed to determine the effect of CF extracton melanogenesis in B16 cells, particularly its specific effects on tyrosinase and tyrosinase-related protein 2 (TRP-2). We measured melanin contents and analyzed melanosome associated protein levels using Western blot and Reverse transcription-polymerase chian reaction (RT-PCR) analysis. CF extract markedly inhibited melanin synthesis and tyrosinase activity. In addition, cellular dendricity was slightly decreased by CF extract. In further experiments, CF extract significantly reduced the protein levels of tyrosinase and TRP-2 in B16 cells. RT-PCR analysis revealed that tyrosinase and TRP-2 mRNA levels were unaffected by CF treatment. Therefore, these results suggest that hypopigmentary effect of CF was due to post-translational degradationof tyrosinase and TRP-2.

Effect of PRX-1 Downregulation in the Type 1 Diabetes Microenvironment

  • Yoo, Jong-Sun;Lee, Yun-Jung;Hyung, Kyeong Eun;Yoon, Joo Won;Lee, Ik Hee;Park, So-Young;Hwang, Kwang Woo
    • The Korean Journal of Physiology and Pharmacology
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    • v.16 no.6
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    • pp.463-468
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    • 2012
  • Type 1 diabetes (T1D) is caused by dysregulation of the immune system in the pancreatic islets, which eventually leads to insulin-producing pancreatic ${\beta}$-cell death and destabilization of glucose homeostasis. One of the major characteristics of T1D pathogenesis is the production of inflammatory mediators by macrophages that result in destruction or damage of pancreatic ${\beta}$-cells. In this study the inflammatory microenvironment of T1D was simulated with RAW264.7 cells and MIN6 cells, acting as macrophages and pancreatic ${\beta}$-cells respectably. In this setting, peroxiredoxin-1, an anti-oxidant enzyme was knocked down to observe its functions in the pathogenesis of T1D. RAW264.7 cells were primed with lipopolysaccharide and co-cultured with MIN6 cells while PRX-1 was knocked down in one or both cell types. Our results suggest that hindrance of PRX-1 activity or the deficiency of this enzyme in inflammatory conditions negatively affects pancreatic ${\beta}$-cell survival. The observed decrease in viability of MIN6 cells seems to be caused by nitric oxide production. Additionally, it seems that PRX-1 affects previously reported protective activity of IL-6 in pancreatic ${\beta}$ cells as well. These results signify new, undiscovered roles for PRX-1 in inflammatory conditions and may contribute toward our understanding of autoimmunity.

Role of MAPK Signaling Pathways in Regulating the Hydrophobin Cryparin in the Chestnut Blight Fungus Cryphonectria parasitica

  • So, Kum-Kang;Kim, Dae-Hyuk
    • Mycobiology
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    • v.45 no.4
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    • pp.362-369
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    • 2017
  • We assessed the regulation of cryparin, a class II hydrophobin, using three representative mitogen-activated protein kinase (MAPK) pathways in Cryphonectria parasitica. Mutation of the CpSlt2 gene, an ortholog of yeast SLT2 in the cell wall integrity (CWI) pathway, resulted in a dramatic decrease in cryparin production. Similarly, a mutant of the CpBck1 gene, a MAP kinase kinase kinase gene in the CWI pathway, showed decreased cryparin production. Additionally, mutation of the cpmk1 gene, an ortholog of yeast HOG1, showed decreased cryparin production. However, mutation of the cpmk2 gene, an ortholog of yeast Kss1/Fus3, showed increased cryparin production. The easy-wet phenotype and accumulation of the cryparin transcript in corresponding mutants were consistent with the cryparin production results. In silico analysis of the promoter region of the cryparin gene revealed the presence of binding motifs related to downstream transcription factors of CWI, HOG1, and pheromone responsive pathways including MADS-box- and Ste12-binding domains. Real-time reverse transcriptase PCR analyses indicated that both CpRlm1, an ortholog of yeast RLM1 in the CWI pathway, and cpst12, an ortholog of yeast STE12 in the mating pathway, showed significantly reduced transcription levels in the mutant strains showing lower cryparin production in C. prasitica. However, the transcription of CpMcm1, an ortholog of yeast MCM1, did not correlate with that of the mutant strains showing downregulation of cryparin. These results indicate that three representative MAPK pathways played a role in regulating cryparin production. However, regulation varied depending on the MAPK pathways: the CWI and HOG1 pathways were stimulatory, whereas the pheromone-responsive MAPK was repressive.

The Early Induction of Suppressor of Cytokine Signaling 1 and the Downregulation of Toll-like Receptors 7 and 9 Induce Tolerance in Costimulated Macrophages

  • Lee, Hyo-Ji;Kim, Keun-Cheol;Han, Jeong A;Choi, Sun Shim;Jung, Yu-Jin
    • Molecules and Cells
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    • v.38 no.1
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    • pp.26-32
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    • 2015
  • Toll-like receptors (TLR) 7 and 9 transduce a cellular signal through the MyD88-dependent pathway and induce the production of inflammatory mediators against microbial nucleotide components. The repeated stimulation of TLR4 leads to endotoxin tolerance, but the molecular mechanisms of tolerance induced through the costimulation of individual TLR has not yet been established, although endosomal TLRs share signaling pathways with TLR4. In the present study, mouse macrophages were simultaneously stimulated with the TLR7 agonist, gardiquimod (GDQ), and the TLR9 agonist, CpG ODN 1826, to examine the mechanism and effector functions of macrophage tolerance. Compared with individual stimulation, the costimulation of both TLRs reduced the secretion of TNF-${\alpha}$ and IL-6 through the delayed activation of the NF-${\kappa}B$ pathway; notably, IL-10 remained unchanged in costimulated macrophages. This tolerance reflected the early induction of suppressor of cytokine signaling-1 (SOCS-1), according to the detection of elevated TNF-${\alpha}$ secretion and restored NF-${\kappa}B$ signaling in response to the siRNA-mediated abrogation of SOCS-1 signaling. In addition, the restimulation of each TLRs using the same ligand significantly reduced the expression of both TLRs in endosomes. These findings revealed that the costimulation of TLR7 and TLR9 induced macrophage tolerance via SOCS-1, and the restimulation of each receptor or both TLR7 and TLR9 downregulated TLR expression through a negative feedback mechanisms that protects the host from excessive inflammatory responses. Moreover, the insufficient and impaired immune response in chronic viral infection might also reflect the repeated and simultaneous stimulation of those endosomal TLRs.