• Title/Summary/Keyword: Regulatory mechanisms

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Extracellular Signal-Regulated Kinase Is a Major Enzyme in Korean Mistletoe Lectin-Mediated Regulation of Macrophage Functions

  • Byeon, Se-Eun;Lee, Jae-Hwi;Yu, Tao;Kwon, Moo-Sik;Hong, Sung-Youl;Cho, Jae-Youl
    • Biomolecules & Therapeutics
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    • v.17 no.3
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    • pp.293-298
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    • 2009
  • Korean mistletoe lectin (KML) is the major component found in Viscum album var. (coloratum), displaying anti-cancer and immunostimulating activities. Even though it has been shown to boost host immune defense mechanisms, the regulatory roles of KML on the functional activation of macrophages have not been fully elucidated. In this study, regulatory mechanism of KML on macrophage-mediated immune responses was examined in terms of KML-mediated signaling event. KML clearly induced mRNA expression of tumor necrosis factor (TNF)-$\alpha$, the generation of reactive oxygen species (ROS) and phagocytic uptake in RAW264.7 cells. All of these events were strongly suppressed by U0126, whereas TNF-$\alpha$ mRNA was not diminished by SB203580 and SP600125, indicating ERK as a central enzyme managing KML-induced up-regulation of macrophage functions. Indeed, KML strongly induced the phosphorylation of ERK in a time-dependent manner without altering its total level. Therefore, these data suggest that ERK may be a major signaling enzyme with regulatory property toward various KML-mediated macrophage responses.

Induction of Regulatory Dendritic Cells by Lactobacillus paracasei L9 Prevents Allergic Sensitization to Bovine β-Lactoglobulin in Mice

  • Yang, Jing;Ren, Fazheng;Zhang, Hao;Jiang, Lu;Hao, Yanling;Luo, Xugang
    • Journal of Microbiology and Biotechnology
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    • v.25 no.10
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    • pp.1687-1696
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    • 2015
  • Supplementation with probiotics can protect against the development of food allergies by modulating the host immune response; however, the mechanisms are not fully understood. The objective of this study was to investigate the allergy-reducing effects of regulatory dendritic cells (regDCs) induced by Lactobacillus paracasei L9 (L9) in β-lactoglobulin (BLG)-sensitized mice. The L9 supplement suppressed the aberrant balance of Th1/Th2 responses to BLG in mice, via upregulation of the CD4+CD25+Foxp3+Treg cell responses. The amount of CD4+CD25+Foxp3+Treg cells in mesenteric lymph nodes increased by 51.85%. Furthermore, administration of L9 significantly induced the expression of CD103 and reduced the maturation status of DCs in mesenteric lymph nodes, Peyer's patches, and spleen. Bone marrow-derived dendritic cells (BM-DCs) were activated by L9 in vitro, with an approximate 1.31-fold and 19.57-fold increase in expression of CD103 in CD11c+DCs and the level of IL-10 production, respectively, while the expression of CD86 did not change significantly. These data demonstrate that L9 reduced the BLG allergic sensitization, likely through regDCs mediated active suppression.

Celastrol suppresses expression of adhesion molecules and chemokines by inhibiting JNK-STAT1/NF-κB activation in poly(I:C)-stimulated astrocytes

  • An, Soo Yeon;Youn, Gi Soo;Kim, Hyejin;Choi, Soo Young;Park, Jinseu
    • BMB Reports
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    • v.50 no.1
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    • pp.25-30
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    • 2017
  • In the central nervous system, viral infection can induce inflammation by up-regulating pro-inflammatory mediators that contribute to enhanced infiltration of immune cells into the central nervous areas. Celastrol is known to exert various regulatory functions, including anti-microbial activities. In this study, we investigated the regulatory effects and the mechanisms of action of celastrol against astrocytes activated with polyinosinic-polycytidylic acid (poly(I:C)), a synthetic dsRNA, as a model of pro-inflammatory mediated responses. Celastrol significantly inhibited poly(I:C)-induced expression of adhesion molecules, such as ICAM-1/VCAM-1, and chemokines, such as CCL2, CXCL8, and CXCL10, in CRT-MG human astroglioma cells. In addition, celastrol significantly suppressed poly(I:C)-induced activation of JNK MAPK and STAT1 signaling pathways. Furthermore, celastrol significantly suppressed poly(I:C)-induced activation of the $NF-{\kappa}B$ signaling pathway. These results suggest that celastrol may exert its regulatory activity by inhibiting poly(I:C)-induced expression of pro-inflammatory mediators by suppressing activation of JNK MAPK-STAT1/$NF-{\kappa}B$ in astrocytes.

Subcloning and DNA Sequencing of the Phenol Regulatory Genes in Ralstonia eutropha JMP134 (Ralstonia eutropha JMP134에서 페놀분해에 관여하는 조절유전자의 Subcloning 및 염기서열 분석)

  • ;Subramanian Chitra
    • Korean Journal of Microbiology
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    • v.38 no.4
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    • pp.260-266
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    • 2002
  • In this study, chromosomal DNA fragment related to the regulation of phenol metabolism in Ralstonia eutropha JMP 134 was cloned and sequenced. The result has shown that two open reading frames (ORF1 and ORF2) exist on this regulatory region. ORF1, which initiates from 454 bp downstream of the stop codon of the phenol hydroxylase genes, was found to be composed of 501 amino acids. ORF2, whose start codon is overlapped with the stop codon of ORFl, was found to contain 232 amino acids. The comparison of amino acid sequences with other proteins has revealed that ORF1 belongs to the family of NtrC transcriptional activator, whereas ORF2 shares high homology with the family of GntR protein, which is known to be a negative regulator. ORF1 and ORF2 were designated as a putative positive regulator, phlR2 and a negative regulator phlA, respectively. Possible regulatory mechanisms of phenol metabolism in this strain was discussed.

Ginsenoside Rc from Panax ginseng exerts anti-inflammatory activity by targeting TANK-binding kinase 1/interferon regulatory factor-3 and p38/ATF-2

  • Yu, Tao;Yang, Yanyan;Kwak, Yi-Seong;Song, Gwan Gyu;Kim, Mi-Yeon;Rhee, Man Hee;Cho, Jae Youl
    • Journal of Ginseng Research
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    • v.41 no.2
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    • pp.127-133
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    • 2017
  • Background: Ginsenoside Rc (G-Rc) is one of the major protopanaxadiol-type saponins isolated from Panax ginseng, a well-known medicinal herb with many beneficial properties including anticancer, anti-inflammatory, antiobesity, and antidiabetic effects. In this study, we investigated the effects of G-Rc on inflammatory responses in vitro and examined the mechanisms of these effects. Methods: The in vitro inflammation system used lipopolysaccharide-treated macrophages, tumor necrosis $factor-{\alpha}/interferon-{\gamma}-treated$ synovial cells, and HEK293 cells transfected with various inducers of inflammation. Results: G-Rc significantly inhibited the expression of macrophage-derived cytokines, such as tumor necrosis $factor-{\alpha}$ and $interleukin-1{\beta}$. G-Rc also markedly suppressed the activation of TANK-binding kinase $1/I{\kappa}B$ kinase ${\varepsilon}/interferon$ regulatory factor-3 and p38/ATF-2 signaling in activated RAW264.7 macrophages, human synovial cells, and HEK293 cells. Conclusion: G-Rc exerts its anti-inflammatory actions by suppressing TANK-binding kinase $1/I{\kappa}B$ kinase ${\varepsilon}/interferon$ regulatory factor-3 and p38/ATF-2 signaling.

A Comparative Study on the Components & Characteristics of the Public Private Partnership Mechanism on Science & Technology Innovation Policy (국가과학기술혁신 민.관협력 메카니즘의 구성요소에 대한 비교연구: 4개국 사례를 중심으로)

  • Park, Yong-Sung
    • Journal of Korea Technology Innovation Society
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    • v.11 no.2
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    • pp.194-218
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    • 2008
  • The public-private partnership concept can encompass a broad range of cooperative relations and a broad variety of programmes in terns of size, objectives and design. This paper aims to analyze the components of public-private partnership mechanisms in the context of science and technology innovation policy. The research methodologies are based on semi-structured interviews with policy makers in four countries with six PPP programme : the France, the Netherlands, the Australia and Austria. It also attempts to understanding of the components that explain the increase of collaboration between national innovation system and PPPs. The taxonomy and essential components of PPPs were identified : mission-oriented PP/Ps, market-Oriented PP/Ps, cluster-oriented PP/Ps, and ISRs-Oriented PP/Ps. The taxonomy of regulatory regime can be a reference point for identifying the relative status of Korea's PPPs.

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The Regulation Mechanisms of Kinesin Motor Proteins (Kinesin 모터 단백질의 조절 기전)

  • Park, Sang Jun;Seog, Joung-Su;Moon, Il Soo;Seog, Dae-Hyun
    • Journal of Life Science
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    • v.27 no.7
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    • pp.840-848
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    • 2017
  • Proper intracellular transport is essential for normal cell function. Intracellular transport is mediated by microtubule-dependent molecular motor proteins, as well as kinesin and cytoplasmic dynein, which move their cargo along long, microtubule tracks in cells. Kinesins are ATP-dependent plus-end-directed motor proteins in the intracellular transport of organelles, vesicles, RNA complexes, and protein complexes. The mislocalization of these different types of cargo has been linked to cell dysfunction and degeneration. The cargo transport of kinesins can be described by the following steps: binding to the appropriate cargo and/or adaptor proteins, activation of the kinesin's motility and movement along the microtubule, and the release of the cargo at the correct destination. Recently, several studies have revealed the mechanisms for the regulation of kinesin motor activity, including cargo loading and unloading. Intracellular cargo transport is also modulated by adaptor proteins, which link the kinesins to their cargo. The regulatory proteins, which include protein kinases and phosphatases, regulate kinesin motor activity directly through the phosphorylation or dephosphorylation of kinesins and indirectly through the modification of adaptor proteins, such as c-Jun NH-terminal kinase-interacting proteins, or of the microtubule network. These findings lay the groundwork for understanding how kinesins are differentially engaged in intracellular cargo transport. In addition, understanding the regulatory mechanisms of each kinesin is an area of key interest within cell biology and neurophysiology. In this study, we reviewed kinesins' regulation proteins and discuss how their regulation affects cargo recognition and transport.

The Biological Functions of Plant Long Noncoding RNAs (식물의 긴비암호화 RNA들의 생물학적 기능)

  • Kim, Jee Hye;Heo, Jae Bok
    • Journal of Life Science
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    • v.26 no.9
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    • pp.1097-1104
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    • 2016
  • With the development of next generation sequencing (NGS), large numbers of transcriptional molecules have been discovered. Most transcripts are non -coding RNAs (ncRNAs). Among them, long non-coding RNAs (lncRNAs) with more than 200 nucleotides represent functional RNA molecule that will not be translated into protein. In plants, lncRNAs are transcribed by RNA polymerase II (Pol II) or Pol III, Pol VI and Pol V. After transcription of these lncRNAs, more RNA processing mechanisms such as splicing and polyadenylation occurs. The expression of plant lncRNAs is very low and is tissue specific. However, these lncRNAs are strongly induced by specific external stimuli. Because different external stimuli including environmental stresses induce a large number of plant lncRNAs, these lncRNAs have been gradually considered as new regulatory factors of various biological and development processes such as epigenetic repression, chromatin modification, target mimicry, photomorphogenesis, protein relocalization, environmental stress response, pathogen infection in plants. Moreover, some lncRNAs act as precursor of short RNAs. Although a large number of lncRNAs have been predicted and identified in plants, our current understanding of the biological function of these lncRNAs is still limited and their detailed regulatory mechanisms should be elucidated continuously. Here, we reviewed the biogenesis and regulation mechanisms of lncRNAs and summarized the molecular functions unraveled in plants.

Regulation of Fumonisin Biosynthesis in Fusarium verticillioides-Maize System

  • Sagaram Uma Shankar;Kolomiets Mike;Shim Won-Bo
    • The Plant Pathology Journal
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    • v.22 no.3
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    • pp.203-210
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    • 2006
  • Fumonisins are a group of mycotoxins produced by a pathogen Fusarium verticillioides in infected maize kernels. Consumption of fumonisin-contaminated maize has been implicated in a number of animal and human illnesses, including esophageal cancer and neural tube defects. Since the initial discovery, chemistry, toxicology, and biology of fumonisins as well as the maize-Fusarium pathosystem have been extensively studied. Furthermore, in the past decade, significant progress has been made in terms of understanding the molecular biology of toxin biosynthetic genes. However, there is a critical gap in our understanding of the regulatory mechanisms involved in fumonisin biosynthesis. Here, we review and discuss our current knowledge about the molecular mechanisms by which fumonisin biosynthesis is regulated in F. verticillioides. In addition, we discuss the impact of maize kernel environment, particularly sugar and lipid molecules, on fumonisin biosynthesis.

Impact of Corporate Governance Mechanisms on Corporate Social Responsibility Disclosure of Publicly-Listed Banks in Bangladesh

  • JAHID, Md. Abu;RASHID, Md. Harun Ur;HOSSAIN, Syed Zabid;HARYONO, Siswoyo;JATMIKO, Bambang
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.6
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    • pp.61-71
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    • 2020
  • The study examines the impact of corporate governance mechanisms, such as board characteristics on corporate social responsibility disclosure (CSRD). The data on CSRD items and board characteristics have been collected by content analysis of the annual reports of 30 publicly-listed banks in Bangladesh covering six years, from 2013 to 2018. More specifically, the directors' report, the chairman's statement, notes to the financial statement and CSR disclosure reports included in annual reports were used to collect the CSRD data. The empirical analysis applies the ordinary least square and the generalized method of moments. The results of the study have revealed that board size, board independence, female board member, and foreign directors have a significant positive impact on CSRD. By contrast, political directors and audit committee size have a negative impact on CSRD. Interestingly, accounting experts on boards ensure more CSRD as they curb the influence of politicians on the board. Thus, it is better to increase accounting experts and decrease politicians on the board. These findings provide valuable insights into the process of forming a suitable CSR policy by connecting the efforts of the board, government, and regulatory bodies to enhance the performance of banks to CSR as well as to CSRD.