• 제목/요약/키워드: defense signaling

검색결과 196건 처리시간 0.026초

Oleanolic acid regulates NF-κB signaling by suppressing MafK expression in RAW 264.7 cells

  • Hwang, Yu-Jin;Song, Jaewhan;Kim, Haeng-Ran;Hwang, Kyung-A
    • BMB Reports
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    • 제47권9호
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    • pp.524-529
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    • 2014
  • Oxidative stress and inflammation are common to many pathological conditions. Defense mechanisms protect cells from oxidative stress, but can become over-activated following injury and inflammation. NF-${\kappa}B$ and Nrf2 transcription factors regulate proinflammatory and antioxidant gene expression, respectively. Studies have shown that many natural dietary compounds regulate NF-${\kappa}B$ and Nrf2, preventing inflammation and oxidative stress. Here, we report major compounds of Prunella vulgaris var. lilacina such as rosmarinic acid, oleanolic acid, ursolic acid and caffeic acid as a potential therapeutic for oxidative stress and inflammation. The major compounds exhibited high anti-inflammatory activity, inhibiting NO, PGE2 production, NF-${\kappa}B$ expression and activating Nrf2 expression. In addition, we examined the effect of major compounds on MafK expression. Among the compounds, oleanolic acid significantly decreased MafK expression and MafK-mediated p65 acetylation. These findings suggest that oleanolic acid as NF-${\kappa}B$ inhibitors can potentially be used in therapeutic applications for the treatment of oxidative stress-induced diseases.

한약재-식물성천연화학물질의 항산화 효능 및 기전 (Anti-Oxidant Efficiency and Memchanisms of Phytochemicals from Traditional Herbal Medicine)

  • 김종봉
    • 대한예방한의학회지
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    • 제12권1호
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    • pp.103-118
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    • 2008
  • Antioxidants are compounds that protect cells against the damaging effects of reactive oxygen species (ROS). Some ROS, such as superoxide and hydrogen peroxide, are normally produced in cells as by-products of biochemical reactions or as signaling molecules. When ROS-generating reactions are activated excessively, pathological quantities of ROS are released to create an imbalance between antioxidants and ROS, called as oxidative stress. Oxidative stress, which may result in cellular damage, has been linked to cardiovascular disease, diabetes, cancer, and other degenerative conditions. In humans the first line of antioxidant defence are the antioxidant enzymes, especially SOD, glutathione peroxidase (GPX), and to a lesser extent catalase, as well as the tripeptide glutathione(GSH). These enzymes will help destroy ROS(reactive oxygen species) such as hydroxyl radical, $H_2O_2$ and lipid peroxides, while GSH protects against oxidized protein. Many herbal medicines possess antioxidant properties. Herbal antioxidants may protect against these diseases by contributing to the total antioxidant defense system of the human body. Here, many herbal medicines including Ginseng, Licorice, Ligusticum Chuanxiong, Ginkgo biloba and many others was reviewed in terms of anti-oxidant efficiency related to their components.

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Roles of Oxidative Stress in the Development and Progression of Breast Cancer

  • Nourazarian, Ali Reza;Kangari, Parisa;Salmaninejad, Arash
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권12호
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    • pp.4745-4751
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    • 2014
  • Oxidative stress is caused by an imbalance in the redox status of the body. In such a state, increase of free radicals in the body can lead to tissue damage. One of the most important species of free radicals is reactive oxygen species (ROS) produced by various metabolic pathways, including aerobic metabolism in the mitochondrial respiratory chain. It plays a critical role in the initiation and progression of various types of cancers. ROS affects different signaling pathways, including growth factors and mitogenic pathways, and controls many cellular processes, including cell proliferation, and thus stimulates the uncontrolled growth of cells which encourages the development of tumors and begins the process of carcinogenesis. Increased oxidative stress caused by reactive species can reduce the body's antioxidant defense against angiogenesis and metastasis in cancer cells. These processes are main factors in the development of cancer. Bimolecular reactions cause free radicals in which create such compounds as malondialdehyde (MDA) and hydroxyguanosine. These substances can be used as indicators of cancer. In this review, free radicals as oxidizing agents, antioxidants as the immune system, and the role of oxidative stress in cancer, particularly breast cancer, have been investigated in the hope that better identification of the factors involved in the occurrence and spread of cancer will improve the identification of treatment goals.

Oak Wood Vinegar Suppresses the Expression of Cyclooxygenase-2 Induced by TLR4 Agonist

  • Yun, Sae-Mi;Park, Se-Jeong;Lee, A-Neum;Ahn, Sang-Il;Youn, Hyung-Sun
    • 대한의생명과학회지
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    • 제15권3호
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    • pp.257-260
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    • 2009
  • Toll-like receptors (TLRs) recognize molecular structures derived from microbes including bacteria, viruses, yeast, and fungi. TLRs have emerged as a major signaling component of the mammalian host defense. TLR4 is a member of the Toll family that senses lipopolysaccharide (LPS), a cell wall component of gram negative bacteria. LPS recognition by TLR4 requires an additional accessory molecule, MD-2. LPS induces the activation of NF-${\kappa}B$ and IRF3 through MyD88 or TRIF-dependent pathways. The activation of NF-${\kappa}B$ leads to the induction of inflammatory gene products including cytokines and cyclooxygenase-2 (COX-2). This study was carried out to investigate the anti-inflammatory effects of oak wood vinegar. Oak wood vinegar inhibits the NF-${\kappa}B$ activation and COX-2 expression induced by LPS. These results provide new ideas to understand the mechanism of oak wood vinegar for its anti-bacterial and anti-inflammatory activities.

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Genome Wide Expression Profile of Agrimonia pilosa in LPS-stimulated BV-2 Microglial Cells

  • Sohn, Sung-Hwa;Ko, Eun-Jung;Kim, Sung-Hoon;Kim, Yang-Seok;Shin, Min-Kyu;Hong, Moo-Chang;Bae, Hyun-Su
    • Molecular & Cellular Toxicology
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    • 제5권1호
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    • pp.1-6
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    • 2009
  • Microglial cells constitute the first line of defense against infection and injury in the brain. This study was conducted to evaluate the protective mechanisms of Agrimonia pilosa (AP) on LPS-induced activation of BV-2 microglial cells. The effects of AP on gene expression profiles in activated BV-2 microglial cells were evaluated using microarray analysis. BV-2 microglial cells were cultured in a 100 mm dish ($1{\times}10^7/mL$) for 24 hr and then pretreated with 1 g/mL AP or left untreated for 30 min. Next, 1 g/mL LPS was added to the samples and the cells were reincubated at $37^{\circ}C$ for 30 min, 3 hr and 6 hr. The gene expression profiles of the BV-2 microglial cells varied depending on the AP. The microarray analysis revealed that MAPK signaling pathway-related genes were down-regulated and IL10 gene was up-regulated in AP-treated BV-2 microglial cells. AP can affect the inflammatory response and MAPK pathway in BV-2 microglial cells.

Invisible Signals from the Underground: Bacterial Volatiles Elicit Plant Growth Promotion and Induce Systemic Resistance

  • Ryu, Choong-Min;Farag, Mohammed A.;Pare, Paul. W.;Kloepper, Joseph W.
    • The Plant Pathology Journal
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    • 제21권1호
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    • pp.7-12
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    • 2005
  • Plant growth-promoting rhizobacteria (PGPR) are a wide range of root-colonizing bacteria with the capacity to enhance plant growth and control plant pathogens. Here we review recent progress that indicate some PGPR strains release a blend of volatile organic compounds (VOCs) that promote growth in Arabidopsis seedlings and induce resistance against Erwinia carotovora subsp. carotovora. In particular, the volatile components 2,3-butanediol and acetoin released exclusively from the PGPR strains triggered the greatest level of growth promotion and induced systemic resistance. Pharmacological applications of 2,3-butanediol promoted the plant growth and induced resistance, while bacterial mutants blocked in 2,3-butanediol and acetoin synthesis was devoid of growth-promotion and induced resistance capacities. The results suggested that the bacterial VOCs play a critical role in the plant growth promotion and induced resistance by PGPR. Using transgenic and mutant lines of Arabidopsis, we provide evidences that the signal pathway activated by volatiles from one PGPR strain is dependent on cyto-kinin activation for growth promotion and dependent on an ethylene-signaling pathway for induced pathogen resistance. This discovery provides new insight into the role of bacterial VOCs as initiators of both plant growth promotion and defense responses in plants.

Caffeine-induced food-avoidance behavior is mediated by neuroendocrine signals in Caenorhabditis elegans

  • Min, Hyemin;Youn, Esther;Kawasaki, Ichiro;Shim, Yhong-Hee
    • BMB Reports
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    • 제50권1호
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    • pp.31-36
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    • 2017
  • High-dose caffeine uptake is a developmental stressor and causes food-avoidance behavior (aversion phenotype) in C. elegans, but its mode of action is largely unknown. In this study, we investigated the molecular basis of the caffeine-induced aversion behavior in C. elegans. We found that aversion phenotype induced by 30 mM caffeine was mediated by JNK/MAPK pathway, serotonergic and dopaminergic neuroendocrine signals. In this process, the dopaminergic signaling appears to be the major pathway because the reduced aversion behavior in cat-2 mutants and mutants of JNK/MAPK pathway genes was significantly recovered by pretreatment with dopamine. RNAi depletion of hsp-16.2, a cytosolic chaperone, and cyp-35A family reduced the aversion phenotype, which was further reduced in cat-2 mutants, suggesting that dopaminergic signal is indeed dominantly required for the caffeine-induced food aversion. Our findings suggest that aversion behavior is a defense mechanism for worms to survive under the high-dose caffeine conditions.

Proteomic Analysis of the Oxidative Stress Response Induced by Low-Dose Hydrogen Peroxide in Bacillus anthracis

  • Kim, Sang Hoon;Kim, Se Kye;Jung, Kyoung Hwa;Kim, Yun Ki;Hwang, Hyun Chul;Ryu, Sam Gon;Chai, Young Gyu
    • Journal of Microbiology and Biotechnology
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    • 제23권6호
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    • pp.750-758
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    • 2013
  • Anthrax is a bacterial disease caused by the aerobic spore-forming bacterium Bacillus anthracis, which is an important pathogen owing to its ability to be used as a terror agent. B. anthracis spores can escape phagocytosis and initiate the germination process even in antimicrobial conditions, such as oxidative stress. To analyze the oxidative stress response in B. anthracis and thereby learn how to prevent antimicrobial resistance, we performed protein expression profiling of B. anthracis strain HY1 treated with 0.3 mM hydrogen peroxide using a comparative proteomics-based approach. The results showed a total of 60 differentially expressed proteins; among them, 17 showed differences in expression over time. We observed time-dependent changes in the production of metabolic and repair/protection signaling proteins. These results will be useful for uncovering the metabolic pathways and protection mechanisms of the oxidative response in B. anthracis.

Touch-induced gene (IbTCH1) from sweet potato [Ipomoea batatas (L.) Lam.]: molecular cloning and functional analysis

  • Seo, Sang-Gyu;Kim, Ji-Seong;Kang, Seung-Won;Shin, Mi-Rae;Yang, You-Sun;Lee, Gung-Pyo;Hong, Jin-Sung;Kim, Sun-Hyung
    • Plant Biotechnology Reports
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    • 제2권4호
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    • pp.253-258
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    • 2008
  • The cDNA of the touch-induced genes (TCH) of the sweet potato [Ipomoea batatas (L.) Lam.] has been cloned and analyzed. IbTCH1, which exists as at least two-copy genes in the genome of the sweet potato, encodes for 148-amino acid polypeptides, and harbors four conversed $Ca^{2+}-binding$ motif EF-hands. IbTCH1 was shown to be expressed in the flower, leaf, thick pigmented root, and particularly in the white fibrous root, but expressed only weakly in the petiole. IbTCH1 is upregulated upon exposure to environmental stresses, dehydration, and jasmonic acid. Furthermore, IbTCH1 is developmentally regulated in the leaf and root. These results strongly indicate that the gene performs functions in both plant development and in defense/stress-signaling pathways.

Application of Jasmonic Acid Followed by Salicylic Acid Inhibits Cucumber mosaic virus Replication

  • Luo, Ying;Shang, Jing;Zhao, Pingping;Xi, Dehui;Yuan, Shu;Lin, Honghui
    • The Plant Pathology Journal
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    • 제27권1호
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    • pp.53-58
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    • 2011
  • Systemic acquired resistance is a form of inducible resistance that is triggered in systemic healthy tissues of local-infected plants. Several candidate signaling molecules emerged in the past two years, including the methylated derivatives of well-known defense hormones salicylic acid (SA) and jasmonic acid (JA). In our present study, the symptom on Cucumber mosaic virus (CMV) infected Arabidopsis leaves in 0.1 mM SA or 0.06 mM JA pre-treated plants was lighter (less reactive oxygen species accumulation and less oxidative damages) than that of the control group. JA followed by SA (JA${\rightarrow}$SA) had the highest inhibitory efficiency to CMV replication, higher than JA and SA simultaneous co-pretreatment (JA+SA), and higher than a JA or a SA single pretreatment. The crosstalk between the two hormones was further investigated at the transcriptional levels of pathogenesis-related genes. The time-course measurement showed JA might play a more important role in the interaction between JA and SA.