• Title/Summary/Keyword: signal pathways

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Anti-inflammatory Effects of Cheongnoimyungshin-hwan in Microglia Cells (미세아교세포의 염증반응에 미치는 청뇌명신환의 영향)

  • Im, Yong-Gyun;Choi, Yung-Hyun;Hwang, Won-Deok
    • Journal of Oriental Neuropsychiatry
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    • v.25 no.4
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    • pp.423-434
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    • 2014
  • Objectives: Activated microglia cells play an important role in inflammatory responses in the central nervous system (CNS) which are involved in neurodegenerative diseases. We attempted to determine the anti-inflammatory effects of Cheongnoimyungshin-hwan (CNMSH) in microglia cells. Methods: We examined the effect of CNMSH on the inflammatory responses in BV2 microglia cells induced by lipopolysaccharide (LPS) and explored the mechanism underlying the action of CNMSH. Results: BV2 cells treated with LPS showed an up-regulation of nitric oxide (NO), prostaglandin $PGE_2(PGE_2)$ and interleukin $1{\beta}(IL-1{\beta})$ release, whereas CNMSH suppressed this up-regulation. CNMSH inhibited the induction of COX-2, iNOS and $IL-1{\beta}$ proteins in LPS-treated BV2 cells and blocked the LPS-induced phosphorylation and nuclear translocation of nuclear factor ${\kappa}B(NF-{\kappa}B$). Furthermore, CNMSH attenuated the LPS-induced phosphorylation of extracellular signal-regulated kinase and p38 mitogen activated protein kinase (MAPK), as well as the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway, but did not inhibit the LPS-induced phosphorylation of c-Jun amino terminal kinase. Conclusions: These results suggest that the inhibitory effect of CNMSH on the LPS-induced production of inflammatory mediators and cytokines in BV2 cells is associated with the suppression of the $NF-{\kappa}B$ and PI3KAkt signaling pathways.

Self-Sufficient Catalytic System of Human Cytochrome P450 4A11 and NADPH-P450 Reductase

  • Han, Song-Hee;Eun, Chang-Yong;Han, Jung-Soo;Chun, Young-Jin;Kim, Dong-Hyun;Yun, Chul-Ho;Kim, Dong-Hak
    • Biomolecules & Therapeutics
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    • v.17 no.2
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    • pp.156-161
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    • 2009
  • The human cytochrome P450 4A11 is the major monooxygenase to oxidize the fatty acids and arachidonic acid. The production of 20-hydroxyeicosatetraenoic acid by P450 4A11 has been implicated in the regulation of vascular tone and blood pressure. Oxidation reaction by P450 4A11 requires its reduction partners, NADPH-P450 reductase (NPR). We report the functional expression in Escherichia coli of bicistronic constructs consisting of P450 4A11 encoded by the first cistron and the electron donor protein, NPR by the second. Typical P450 expression levels of wild type and several N-terminal modified mutants was observed in culture media and prepared membrane fractions. The expression of functional NPR in the constructed P450 4A11: NPR bicistronic system was clearly verified by reduction of nitroblue tetrazolium. Membrane preparation containing P450 4A11 and NPR efficiently oxidized lauric acid mainly to $\omega$-hydroxylauric acid. Bicistronic coexpression of P450 4A11 and NPR in E. coli cells can be extended toward identification of novel drug metabolites or therapeutic agents involved in P450 4A11 dependent signal pathways.

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.

Transcriptome profiling and identification of functional genes involved in H2S response in grapevine tissue cultured plantlets

  • Ma, Qian;Yang, Jingli
    • Genes and Genomics
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    • v.40 no.12
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    • pp.1287-1300
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    • 2018
  • Hydrogen sulfide ($H_2S$), a small bioactive gas, has been proved functioning in plant growth and development as well as alleviation of abiotic stresses, which including promoting seed germination, accelerating embryonic root growth, regulating flower senescence, inducing stomatal closure, and defending drought, heat, heavy metals and osmotic stresses etc. However, the molecular functioning mechanism of $H_2S$ was still unclear. The primary objective of this research was to analyze the transcriptional differences and functional genes involved in the $H_2S$ responses. In details, 4-week-old plantlets in tissue culture of grapevine (Vitis vinifera L.) cultivar 'Zuoyouhong' were sprayed with 0.1 mM NaHS for 12 h, and then transcriptome sequencing and qRT-PCR analysis were used to study the transcriptional differences and functional genes involved in the $H_2S$ responses. Our results indicated that 650 genes were differentially expressed after $H_2S$ treatment, in which 224 genes were up-regulated and 426 genes were down-regulated. The GO enrichment analysis and KEGG enrichment analysis results indicated that the up-regulated genes after $H_2S$ treatment focused on carbon metabolism, biosynthesis of amino acids, and glycolysis/gluconeogenesis, and the down-regulated genes were mainly in metabolic pathways, biosynthesis of secondary metabolites, and plant hormone signal transduction. Analyzing the transcription factor coding genes in details, it was indicated that 10 AP2/EREBPs, 5 NACs, 3 WRKYs, 3 MYBs, and 2 bHLHs etc. transcription factor coding genes were up-regulated, while 4 MYBs, 3 OFPs, 3 bHLHs, 2 AP2/EREBPs, 2 HBs etc. transcription factor coding genes were down-regulated. Taken together, $H_2S$ increased the productions in secondary metabolites and a variety of defensive compounds to improve plant development and abiotic resistance, and extend fruits postharvest shelf life by regulating the expression of AP2/EREBPs, WRKYs, MYBs, CABs, GRIP22, FERRITINs, TPSs, UGTs, and GHs etc.

Different effects of prolonged β-adrenergic stimulation on heart and cerebral artery

  • Shin, Eunji;Ko, Kyung Soo;Rhee, Byoung Doo;Han, Jin;Kim, Nari
    • Integrative Medicine Research
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    • v.3 no.4
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    • pp.204-210
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    • 2014
  • The aim of this review was to understand the effects of ${\beta}$-adrenergic stimulation on oxidative stress, structural remodeling, and functional alterations in the heart and cerebral artery. Diverse stimuli activate the sympathetic nervous system, leading to increased levels of catecholamines. Long-term overstimulation of the ${\beta}$-adrenergic receptor (${\beta}AR$) in response to catecholamines causes cardiovascular diseases, including cardiac hypertrophy, stroke, coronary artery disease, and heartfailure. Although catecholamines have identical sites of action in the heart and cerebral artery, the structural and functional modifications differentially activate intracellular signaling cascades. ${\beta}AR$-stimulation can increase oxidative stress in the heart and cerebral artery, but has also been shown to induce different cytoskeletal and functional modifications by modulating various components of the ${\beta}AR$ signal transduction pathways. Stimulation of ${\beta}AR$ leads to cardiac dysfunction due to an overload of intracellular $Ca^{2+}$ in cardiomyocytes. However, this stimulation induces vascular dysfunction through disruption of actin cytoskeleton in vascular smooth muscle cells. Many studies have shown that excessive concentrations of catecholamines during stressful conditions can produce coronary spasms or arrhythmias by inducing $Ca^{2+}$-handling abnormalities and impairing energy production in mitochondria, In this article, we highlight the different fates caused by excessive oxidative stress and disruptions in the cytoskeletal proteome network in the heart and the cerebral artery in responsed to prolonged ${\beta}AR$-stimulation.

Bioconversion of Gentiana scabra Bunge increases the anti-inflammatory effect in RAW 264.7 cells via MAP kinases and NF-κB pathway

  • Kim, Min-A;Lee, Han-Saem;Chon, So-Hyun;Park, Jeong-Eun;Lim, Yu-Mi;Kim, Eun-Jeong;Son, Eun-Kyung;Kim, Sang-Jun;So, Jai-Hyun
    • Journal of Applied Biological Chemistry
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    • v.62 no.1
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    • pp.39-50
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    • 2019
  • Mitogen-activated protein (MAP) kinases play an important role in cell growth and differentiation, as well as the modulation of proinflammatory cytokines. The objective of this study was to examine the increase in the anti-inflammatory effect of Gentiana scabra Bunge (GSB), due to bioconversion with the Aspergillus kawachii crude enzyme, via inhibition of the $NF-{\kappa}B$ signaling and MAP kinase pathways in RAW 264.7 cells. The expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 in RAW 264.7 cells treated with the GSB ethyl acetate fraction bioconverted with A. kawachii crude enzyme (GE-BA), was dramatically suppressed as compared to GSB ethyl acetate fraction non-bioconverted with the A. kawachii crude enzyme (GE-UA). The phosphorylation of p38, extracellular signal-regulated kinases, and inhibitory ${\kappa}B$ in RAW 264.7 cells treated with GE-BA was further suppressed, as compared to exposure to GE-UA. Moreover, the mRNA expression of interleukin 6, interleukin 1-beta, and tumor necrosis $factor-{\alpha}$ was further suppressed by GE-BA, compared to GE-UA. Similarly, anti-oxidant activities, such as 2,2-diphenyl-1-picrylhydrazyl hydrate and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging activity, of GE-BA were further increased compared to GE-UA. These observations demonstrate that the anti-oxidant and anti-inflammatory activities of GSB ethyl acetate fraction increases as a result from bioconversion with the A. kawachii crude enzyme.

7,8,4'-Trihydroxyisoflavone, a Metabolized Product of Daidzein, Attenuates 6-Hydroxydopamine-Induced Neurotoxicity in SH-SY5Y Cells

  • Ko, Yong-Hyun;Kim, Seon-Kyung;Kwon, Seung-Hwan;Seo, Jee-Yeon;Lee, Bo-Ram;Kim, Young-Jung;Hur, Kwang-Hyun;Kim, Sun Yeou;Lee, Seok-Yong;Jang, Choon-Gon
    • Biomolecules & Therapeutics
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    • v.27 no.4
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    • pp.363-372
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    • 2019
  • Daidzein isolated from soybean (Glycine max) has been widely studied for its antioxidant and anti-inflammatory activities. However, the protective effects of 7,8,4'-trihydroxyisoflavone (THIF), a major metabolite of daidzein, on 6-hydroxydopamine (OHDA)-induced neurotoxicity are not well understood. In the current study, 7,8,4'-THIF significantly inhibited neuronal cell death and lactate dehydrogenase (LDH) release induced by 6-OHDA in SH-SY5Y cells, which were used as an in vitro model of Parkinson's disease (PD). Moreover, pretreatment with 7,8,4'-THIF significantly increased the levels of superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) and decreased malondialdehyde (MDA) activity in 6-OHDA-induced SH-SY5Y cells. In addition, 7,8,4'-THIF significantly recovered 6-OHDA-induced cleaved caspase-3, cleaved caspase-9, cleaved poly-ADP-ribose polymerase (PARP), increased Bax, and decreased Bcl-2 levels. Additionally, 7,8,4'-THIF significantly restored the expression levels of phosphorylated c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase 1/2 (ERK 1/2), phosphatidylinositol 3-kinases (PI3K)/Akt, and glycogen synthase kinase-3 beta ($GSK-3{\beta}$) in 6-OHDA-induced SH-SY5Y cells. Further, 7,8,4'-THIF significantly increased the reduced tyrosine hydroxylase (TH) level induced by 6-OHDA in SH-SY5Y cells. Collectively, these results suggest that 7,8,4'-THIF protects against 6-OHDA-induced neuronal cell death in cellular PD models. Also, these effects are mediated partly by inhibiting activation of the MAPK and PI3K/Akt/$GSK-3{\beta}$ pathways.

Neuroprotective Effect of Astersaponin I against Parkinson's Disease through Autophagy Induction

  • Zhang, Lijun;Park, Jeoung Yun;Zhao, Dong;Kwon, Hak Cheol;Yang, Hyun Ok
    • Biomolecules & Therapeutics
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    • v.29 no.6
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    • pp.615-629
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    • 2021
  • An active compound, triterpene saponin, astersaponin I (AKNS-2) was isolated from Aster koraiensis Nakai (AKNS) and the autophagy activation and neuroprotective effect was investigated on in vitro and in vivo Parkinson's disease (PD) models. The autophagy-regulating effect of AKNS-2 was monitored by analyzing the expression of autophagy-related protein markers in SH-SY5Y cells using Western blot and fluorescent protein quenching assays. The neuroprotection of AKNS-2 was tested by using a 1-methyl-4-phenyl-2,3-dihydropyridium ion (MPP+)-induced in vitro PD model in SH-SY5Y cells and an MPTP-induced in vivo PD model in mice. The compound-treated SH-SY5Y cells not only showed enhanced microtubule-associated protein 1A/1B-light chain 3-II (LC3-II) and decreased sequestosome 1 (p62) expression but also showed increased phosphorylated extracellular signal-regulated kinases (p-Erk), phosphorylated AMP-activated protein kinase (p-AMPK) and phosphorylated unc-51-like kinase (p-ULK) and decreased phosphorylated mammalian target of rapamycin (p-mTOR) expression. AKNS-2-activated autophagy could be inhibited by the Erk inhibitor U0126 and by AMPK siRNA. In the MPP+-induced in vitro PD model, AKNS-2 reversed the reduced cell viability and tyrosine hydroxylase (TH) levels and reduced the induced α-synuclein level. In an MPTP-induced in vivo PD model, AKNS-2 improved mice behavioral performance, and it restored dopamine synthesis and TH and α-synuclein expression in mouse brain tissues. Consistently, AKNS-2 also modulated the expressions of autophagy related markers in mouse brain tissue. Thus, AKNS-2 upregulates autophagy by activating the Erk/mTOR and AMPK/mTOR pathways. AKNS-2 exerts its neuroprotective effect through autophagy activation and may serve as a potential candidate for PD therapy.

Characterization of Phytophthora capsici effector genes and their functional repertoire

  • Arif, Saima;Lim, Gi Taek;Kim, Sun Ha;Oh, Sang-Keun
    • Korean Journal of Agricultural Science
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    • v.48 no.3
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    • pp.643-654
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    • 2021
  • Phytophthora capsici is one of the most destructive hemibiotrophic pathogens; it can cause blight in chili peppers, and secrete various effector proteins to infect the plants. These effectors contain an N-terminal conserved RXLR motif. Here, we generated full-length RXLR effector coding genes using primer pairs, and cloned them into the pGR106 vector for in planta expression. Two of these genes, PcREK6 and PcREK41 (P. capsici RXLR effector from the Korea isolate), were further characterized. PcREK6 and PcREK41 genes showed that they encode effector proteins with a general modular structure, including the N-terminal conserved RXLR-DEER motif and signal peptide sequences. PcREK6 and PcREK41 expressions were strongly induced when the chili pepper plants (Capsicum annuum) were challenged with P. capsici. These results provide molecular evidence to elucidate the virulence or avirulence factors in chili pepper. Our results also showed that two effectors induce hypersensitive response (HR) cell death when expressed in chili leaves. Cell death suppression assays in Nicotiana benthamiana revealed that most effectors could not suppress programmed cell death (PCD) triggered by Bcl-associated X (BAX) or Phytophthora infestans elicitin (INF1). However, PcREK6 fully suppressed PCD triggered by BAX, while PcREK41 partially suppressed PCD triggered by INF1 elicitin. These results suggest that PcREK effectors from P. capsici interact with putative resistance (R) proteins in planta, and different effectors may target different pathways in a plant cell to suppress pattern-triggered immunity (PTI) or effector-triggered immunity (ETI).

L-ascorbic acid induces apoptosis in human laryngeal epidermoid Hep-2 cells by modulating the nuclear factor kappa-light-chain-enhancer of activated B cells/mitogen-activated protein kinase/Akt signaling pathway

  • Park, Jung-Sun;Kim, Yoon-Jung;Park, Sam Young;Chung, Kyung-Yi;Oh, Sang-Jin;Kim, Won-Jae;Jung, Ji-Yeon
    • International Journal of Oral Biology
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    • v.45 no.4
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    • pp.169-178
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    • 2020
  • L-ascorbic acid (L-AA; vitamin C) induces apoptosis in cancer cells. This study aimed to elucidate the molecular mechanisms of L-AA-induced apoptosis in human laryngeal epidermoid carcinoma Hep-2 cells. L-AA suppressed the viability of Hep-2 cells and induced apoptosis, as shown by the cleavage and condensation of nuclear chromatin and increased number of Annexin V-positive cells. L-AA decreased Bcl-2 protein expression but upregulated Bax protein levels. In addition, cytochrome c release from the mitochondria into the cytosol and activation of caspase-9, -8, and -3 were enhanced by L-AA treatment. Furthermore, apoptosis-inducing factor (AIF) and endonuclease G (EndoG) were translocated into the nucleus during apoptosis of L-AA-treated Hep-2 cells. L-AA effectively inhibited the constitutive nuclear factor-κB (NF-κB) activation and attenuated the nuclear expression of the p65 subunit of NF-κB. Interestingly, L-AA treatment of Hep-2 cells markedly activated Akt and mitogen-activated protein kinase (MAPK; extracellular signal-regulated kinase 1/2, p38, and c-Jun N-terminal kinase [JNK]) and and LY294002 (Akt inhibitor), SB203580 (p38 inhibitor) or SP600125 (a JNK inhibitor) decreased the levels of Annexin V-positive cells. These results suggested that L-AA induces the apoptosis of Hep-2 cells via the nuclear translocation of AIF and EndoG by modulating the Bcl-2 family and MAPK/Akt signaling pathways.