• Title/Summary/Keyword: regulatory mechanism

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Candidacidal Effects of Rev (11-20) Derived from HIV-1 Rev Protein

  • Lee, Juneyoung;Lee, Dong Hwan;Lee, Dong Gun
    • Molecules and Cells
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    • v.28 no.4
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    • pp.403-406
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    • 2009
  • Rev is an essential regulatory protein for HIV-1 replication. Rev (11-20) is known as the significant region regarding the function of a nuclear entry inhibitory signal (NIS) of Rev. In this study, anticandidal effects and mechanism of action of Rev (11-20) were investigated. The result exhibited that Rev (11-20) contained candidacidal activities. To understand target site(s) of Rev (11-20), the intracellular localization of the peptide was investigated. The result showed that Rev (11-20) rapidly accumulated in the fungal cell surface. The cell wall regeneration test also indicated that Rev (11-20) exerted its anticandidal activity to fungal plasma membrane rather than cell wall. The fluorescent study using 1,6-diphenyl-1,3,5-hexatriene (DPH) further confirmed the membrane-disruption mechanism(s) of Rev (11-20). The present study suggests that Rev (11-20) possesses significant potential regarding therapeutic agents for treating fungal diseases caused by Candida species in humans.

Suppressing NF-κB/Caspase-1 Activation is a Mechanism Involved in the Anti-inflammatory Effect of Rubi Fructus in Stimulated HMC-1 Cells

  • Mi-Ok Yang;Noh-Yil Myung
    • Biomedical Science Letters
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    • v.29 no.3
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    • pp.137-143
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    • 2023
  • Inflammation plays an important role in immune system's response to tissue injury and biological stimuli. However, excessive inflammation can cause tissue damage. Therefore, the development of naturally derived anti-inflammatory agents have received broad attention. In this study, we investigated the anti-inflammatory mechanism of Rubi Fructus (RF) extract on the mast cell-mediated inflammatory response. To determine the regulatory mechanism of RF in inflammatory reaction, we evaluated the effects of RF on secretion of interleukin (IL)-8, IL-6 and tumor necrosis factor (TNF)-α and activation of nuclear factor-κB (NF-κB) and caspase-1 in activated human mast cells-1 (HMC-1). The results showed that RF attenuated IL-8, IL-6 and TNF-α secretion in a concentration-dependent manner. Moreover, RF significantly attenuated caspase-1and NF-κB activation in activated HMC-1. Conclusively, the present results provide evidence that RF may be a promising agent for anti-inflammatory therapy.

Drivers of Corporate Social Responsibility Leading to Sustainable Development

  • Sy, Maria Victoria U.
    • Industrial Engineering and Management Systems
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    • v.13 no.3
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    • pp.342-355
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    • 2014
  • Organizational dedication to corporate social responsibility (CSR) is set off by a number of driving forces, such as enhancing corporate financial performance, concern for the environment, regulatory compliance, and social equity. This article aims to ascertain the uptake of CSR among firms in the Philippines and Thailand leading to the attainment of sustainable development. The results revealed that CSR is carried out by the companies primarily to enhance their competitive advantage and legal compliance, which are deemed essential to the firms' existence. This study seeks to contribute to understanding how companies undertake their operations based on socially responsible practices so that the theoretical conceptualizations of sustainability can be developed. By determining what prods companies to pursue CSR, it will shed light on the mechanism that promotes the existence of sustainable organizations, linking it with CSR and the companies' objectives and strategies.

A System for Describing Cis-Regulatory Machinery Unit

  • Kaminuma, Tsuguchika;Takai-Igarashi, Takako;Yukawa, Masumi;Tanaka, Yoshitomo;Tanaka, Hiroshi
    • Proceedings of the Korean Society for Bioinformatics Conference
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    • 2005.09a
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    • pp.427-430
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    • 2005
  • Studies on cellular pathways and networks are now one of the most actively researched topics in all fields of biomedicine ranging from developmental biology to etiology. Many databases have been developed and quantitative simulation models have been proposed. One of the eventual goals of pathway/network studies is to integrate different types of pathway/network models and databases to simulate overall cellular responses. A bottleneck to this goal is modeling gene expression since the mechanism of this process is not yet fully unveiled. We are developing a small scale computer program called CiRMU (Cis-Regulatory Machinery Unit model) for describing, viewing, analyzing, and modeling the process of gene expression. A prototype system is being designed and implemented for analyzing functions of nuclear receptors.

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Overview of Innate Immunity in Drosophila

  • Kim, Tae-Il;Kim, Young-Joon
    • BMB Reports
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    • v.38 no.2
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    • pp.121-127
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    • 2005
  • Drosophila protects itself from infection by microbial organisms by means of its pivotal defense, the so-called innate immunity system. This is its sole defense as it lacks an adaptive immunity system such as is found in mammals. The strong conservation of innate immunity systems in organisms from Drosophila to mammals, and the ease with which Drosophila can be manipulated genetically, makes this fly a good model system for investigating the mechanisms of virulence of a number of medically important pathogens. Potentially damaging endogenous and/or exogenous challenges sensed by specific receptors initiate signals via the Toll and/or Imd signaling pathways. These in turn activate the transcription factors Dorsal, Dorsal-related immune factor (Dif) and Relish, culminating in transcription of genes involved in the production of antimicrobial peptides, melanization, phagocytosis, and the cytoskeletal rearrangement required for appropriate responses. Clarifying the regulatory interactions between the various pathways involved is very important for understanding the specificity and termination mechanism of the immune response.

The Regulatory Domain of Troponin C: To Be Flexible or Not To Be Flexible

  • Gagne, Stephane M.;Sykes, Michael T.;Sykes, Brain D.
    • Journal of the Korean Magnetic Resonance Society
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    • v.2 no.2
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    • pp.131-140
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    • 1998
  • The calcium-induced structural changes in the skeletal muscle regulatory protein troponin C (NTnC) involve a transition from a ‘closed’to an ‘open’structure with the concomitant exposure of a large hydrophobic interaction site for target proteins. Structural studies have served to define this conformational change and elucidate the mechanism of the linkage between calcium binding and the induced structural changes. There are now several structures of NTnC available from both NMR and X-ray crystallography. Comparison of the calcium bound structures reveals differences in the level of opening. We have considered the concept of a flexible open state of NTnC as a possible explanation for this apparent discrepancy. We also present simulations of the closed-to-open transition which are in agreement with the flexibility concept and with experimental energetics data.

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Oral Tolerance: Not Simple But more Complex

  • Chung, Yeonseok;Kang, Chang-Yuil
    • IMMUNE NETWORK
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    • v.3 no.3
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    • pp.169-175
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    • 2003
  • The intestinal immune system can discriminate between harmful and unharmful antigens and do not provoke productive immunity to unharmful antigen. Thus oral administration of antigen is one of classical methods for inducing antigen-specific immune tolerance in the periphery. Furthermore, oral tolerance has been investigated for the treatment of autoimmune disorders in human clinical trials. However, the detail mechanism of oral tolerance and contributing factors are not defined clearly at this time. Recent studies demonstrate unique types of immune cell that suppressing immune response, such as regulatory T cell and tolerogenic dendritic cell. This article reviews the factors involved in oral tolerance and discusses our current understanding base on the recent literatures and our works.

RNF43 and ZNRF3 in Wnt Signaling - A Master Regulator at the Membrane

  • Fiona Farnhammer;Gabriele Colozza;Jihoon Kim
    • International Journal of Stem Cells
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    • v.16 no.4
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    • pp.376-384
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    • 2023
  • The Wnt 𝛽-catenin signaling pathway is a highly conserved mechanism that plays a critical role from embryonic development and adult stem cell homeostasis. However, dysregulation of the Wnt pathway has been implicated in various diseases, including cancer. Therefore, multiple layers of regulatory mechanisms tightly control the activation and suppression of the Wnt signal. The E3 ubiquitin ligases RNF43 and ZNRF3, which are known negative regulators of the Wnt pathway, are critical component of Wnt signaling regulation. These E3 ubiquitin ligases control Wnt signaling by targeting the Wnt receptor Frizzled to induce ubiquitination-mediated endo-lysosomal degradation, thus controlling the activation of the Wnt signaling pathway. We also discuss the regulatory mechanisms, interactors, and evolution of RNF43 and ZNRF3. This review article summarizes recent findings on RNF43 and ZNRF3 and their potential implications for the development of therapeutic strategies to target the Wnt signaling pathway in various diseases, including cancer.

MicroRNAs regulate granulosa cells apoptosis and follicular development - A review

  • Gong, Zhuandi;Yang, Juan;Bai, Shengju;Wei, Suocheng
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.11
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    • pp.1714-1724
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    • 2020
  • Objective: MicroRNAs (miRNAs) are the most abundant small RNAs. Approximately 2,000 annotated miRNAs genes have been found to be differentially expressed in ovarian follicles during the follicular development (FD). Many miRNAs exert their regulatory effects on the apoptosis of follicular granulosa cells (FGCs) and FD. However, accurate roles and mechanism of miRNAs regulating apoptosis of FGCs remain undetermined. Methods: In this review, we summarized the regulatory role of each miRNA or miRNA cluster on FGCs apoptosis and FD on the bases of 41 academic articles retrieved from PubMed and web of science and other databases. Results: Total of 30 miRNAs and 4 miRNAs clusters in 41 articles were reviewed and summarized in the present article. Twenty nine documents indicated explicitly that 24 miRNAs and miRNAs clusters in 29 articles promoted or induced FGCs apoptosis through their distinctive target genes. The remaining 10 miRNAs and miRNAs of 12 articles inhibited FGCs apoptosis. MiRNAs exerted modulation actions by at least 77 signal pathways during FGCs apoptosis and FD. Conclusion: We concluded that miRNAs or miRNAs clusters could modulate the apoptosis of GCs (including follicular GCs, mural GCs and cumulus cells) by targeting their specific genes. A great majority of miRNAs show a promoting role on apoptosis of FGCs in mammals. But the accurate mechanism of miRNAs and miRNA clusters has not been well understood. It is necessary to ascertain clearly the role and mechanism of each miRNA or miRNA cluster in the future. Understanding precise functions and mechanisms of miRNAs in FGCs apoptosis and FD will be beneficial in developing new diagnostic and treatment strategies for treating infertility and ovarian diseases in humans and animals.

Numerical Analysis on Feedback Mechanism of Supersonic Impinging Jet using LES (LES를 이용한 초음속 충돌제트의 피드백 메커니즘에 대한 수치해석 연구)

  • Oh, Se-Hong;Choi, Dae Kyung;Kim, Won Tae;Chang, Yoon-Suk;Choi, Choengryul
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.13 no.2
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    • pp.51-59
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    • 2017
  • Steam jets ejected from a rupture zone of high energy pipes may cause damage to adjacent structures. This event could lead to more serious accidents in nuclear power plants. Therefore, to prevent serious accidents, high energy pipes of nuclear power plants are designed according to the ANSI / ANS 58.2 technical standard. However, the US Nuclear Regulatory Commission (USNRC) has recently pointed out non-conservatism in existing high energy pipe fracture evaluation methods, and required the assessment of the unsteady load of the jet caused by a potential feedback mechanism as well as the impact range of steam jet, the jet impact loads and the blast wave effects at the initial breakage stage. The potential feedback mechanism refers to a phenomenon in which a vortex formed by impingement jets amplifies vortex itself and induces jet vibration in a shear layer. In this study, CFD methodology using the LES turbulence model is established and numerical analysis is carried out to evaluate the dynamic behavior of impingement jets and the potential feedback mechanism during jet impingement. Obtained results have been compared with an empirical correlation and experiment.