• 제목/요약/키워드: Network biology

검색결과 509건 처리시간 0.023초

시스템 생리학에 기반한 한열 변증의 이해 (Understanding Cold and Hot Pattern Classification Based on Systems Biology)

  • 이수진
    • 동의생리병리학회지
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    • 제30권6호
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    • pp.376-384
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    • 2016
  • Systems biology is an emerging field aiming at a systems level understanding of living organisms and focusing on the characteristics of the whole network of them. The emergence of systems biology is partly because of the availability of huge amounts of data on organisms and the extensive support of computational technologies as the tools for understanding complex biological systems. The scientific understanding of Korean medicine has been obstructed because of the lack of proper methods examining the complex nature and the unique property of it. However, systems biology could give a chance understanding Korean medicine objectively and scientifically. Pattern classification is a unique tool of Korean medicine to diagnose and treat patients and systems biology would give a useful tool to interpret pattern classification. Various omics technologies has been used to explain the relations between pattern classification and biological factors and then many characteristics of pattern classification in various diseases have been discovered. Therefore, pattern classification could be a bridge to understand the features and differences of western medicine and Korean medicine and it could be a basis to develop pattern-based personalized medicine.

Regulatory Mutations for Anaerobic Inducible Gene Expression in Salmonella typhimurium

  • Soo, Bang;Lee, Yun-Joung;Koh, Sang-Kyun;An, Chung-Sun;Lee, Yung-Nok;Park, Yong-Keun
    • 미생물학회지
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    • 제30권5호
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    • pp.347-354
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    • 1992
  • New regulatory, loci which participate in the regulation of anaerobic inducible gene expression in Salmonella typhimurium were identified. We observed the regulatory network of new regulator mutations to various anaerobic inducible gene (1). Some anaerobic inducible lac fusions were also induced at low pH condition which was severe environment to withstand for its virulence at the place like phagolysosome. Sic oxygen-regulated regulatory mutants (oxr) isolated by Tn10 mutagenesis were divided into two groups. Five of them were found to show negative effect on the regulation of anaerobic gene expression, while on e showed positive effect on the regulation. Genetic loci of four oxr were identified with 54 Mud-P22 lysogens covering the whole chromosome of S. typhimurium, in the nearby region of map unit 87 min (oxr101), 63 min (oxr104), 97 min (oxr 105), and 57 min (oxr 106), respectively. Two oxr mutants were subjected to two-dimensional polyacrylamide electrophoretic analysis of anaerobic inducible proteins for searching the control circuitry of our oxr mutants.

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Enhanced Expression of High-affinity Iron Transporters via H-ferritin Production in Yeast

  • Kim, Kyung-Suk;Chang, Yu-Jung;Chung, Yun-Jo;Park, Chung-Ung;Seo, Hyang-Yim
    • BMB Reports
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    • 제40권1호
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    • pp.82-87
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    • 2007
  • Our heterologous expression system of the human ferritin H-chain gene (hfH) allowed us to characterize the cellular effects of ferritin in yeasts. The recombinant Saccharomyces cerevisiae (YGH2) evidenced impaired growth as compared to the control, which was correlated with ferritin expression and with the formation of core minerals. Growth was recovered via the administration of iron supplements. The modification of cellular iron metabolism, which involved the increased expression of high-affinity iron transport genes (FET3 and FTR1), was detected via Northern blot analysis. The findings may provide some evidence of cytosolic iron deficiency, as the genes were expressed transcriptionally under iron-deficient conditions. According to our results examining reactive oxygen species (ROS) generation via the fluorescence method, the ROS levels in YGH2 were decreased compared to the control. It suggests that the expression of active H-ferritins reduced the content of free iron in yeast. Therefore, present results may provide new insights into the regulatory network and pathways inherent to iron depletion conditions.

Modulation of Kex2p Cleavage Site for In Vitro Processing of Recombinant Proteins Produced by Saccharomyces cerevisiae

  • Mi-Jin Kim;Se-Lin Park;Seung Hwa Kim;Hyun-Joo Park;Bong Hyun Sung;Jung-Hoon Sohn;Jung-Hoon Bae
    • Journal of Microbiology and Biotechnology
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    • 제33권11호
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    • pp.1513-1520
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    • 2023
  • Kex2 protease (Kex2p) is a membrane-bound serine protease responsible for the proteolytic maturation of various secretory proteins by cleaving after dibasic residues in the late Golgi network. In this study, we present an application of Kex2p as an alternative endoprotease for the in vitro processing of recombinant fusion proteins produced by the yeast Saccharomyces cerevisiae. The proteins were expressed with a fusion partner connected by a Kex2p cleavage sequence for enhanced expression and easy purification. To avoid in vivo processing of fusion proteins by Kex2p during secretion and to guarantee efficient removal of the fusion partners by in vitro Kex2p processing, P1', P2', P4, and P3 sites of Kex2p cleavage sites were elaborately manipulated. The general use of Kex2p in recombinant protein production was confirmed using several recombinant proteins.

Streptozotocin, an O-GlcNAcase Inhibitor, Stimulates $TNF\alpha -Induced$ Cell Death

  • Yang Won-Ho;Ju Jung-Won;Cho Jin Won
    • 한국미생물학회:학술대회논문집
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    • 한국미생물학회 2004년도 International Meeting of the Microbiological Society of Korea
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    • pp.65-67
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    • 2004
  • O-GlcNAcylation of p53 has been already identified and reported, but the function of O-GlcNAc on p53 has not been studied well. In this report, the general function of O-GlcNAc modification on p53 has been investigated using mouse fibroblast cell, L929. When streptozotocin (STZ), a non-competitive O-GlcNAcase inhibitor was treated to L929, O-GlcNAc modification level was dramatically increased on nucleocytoplasmic proteins, including p53. Because it has been already reported that $TNF\alpha$ induced the production of p53 in L929, $TNF\alpha$ was treated to obtain more p53. Approximately two times more amount of p53 was found from the cells treated STZ and $TNF\alpha$ simultaneously compared to the cell treated $TNF\alpha$ alone. The p53 increment in the presence of STZ was not caused by the induction of p53 gene expression. When new production of p53 induced by the $TNF\alpha$ was inhibited by the treatment of cycloheximide, O-GlcNAc modification decreased and phosphorylation increased on pre-existing p53 after $TNF\alpha$ treatment. But in the presence of STZ and $TNF\alpha$ at the same time, more O-GlcNAcylation occurred on p53, The level of ubiquitination on p53 was also reduced in the presence of STZ. Approximately three times less amount of Mdm2 bound to this hyperglycosylated p53. From this result it might be concluded that treatment of STZ to inhibit O-GlcNAcase increased O-GlcNAc modification level on p53 and the increment of O-GlcNAc modification stabilized p53 from ubiquitin proteolysis system.

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Network Analyses of Gene Expression following Fascin Knockdown in Esophageal Squamous Cell Carcinoma Cells

  • Du, Ze-Peng;Wu, Bing-Li;Xie, Jian-Jun;Lin, Xuan-Hao;Qiu, Xiao-Yang;Zhan, Xiao-Fen;Wang, Shao-Hong;Shen, Jin-Hui;Li, En-Min;Xu, Li-Yan
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권13호
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    • pp.5445-5451
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    • 2015
  • Fascin-1 (FSCN1) is an actin-bundling protein that induces cell membrane protrusions, increases cell motility, and is overexpressed in various human epithelial cancers, including esophageal squamous cell carcinoma (ESCC). We analyzed various protein-protein interactions (PPI) of differentially-expressed genes (DEGs), in fascin knockdown ESCC cells, to explore the role of fascin overexpression. The node-degree distributions indicated these PPI sub-networks to be characterized as scale-free. Subcellular localization analysis revealed DEGs to interact with other proteins directly or indirectly, distributed in multiple layers of extracellular membrane-cytoskeleton/ cytoplasm-nucleus. The functional annotation map revealed hundreds of significant gene ontology (GO) terms, especially those associated with cytoskeleton organization of FSCN1. The Random Walk with Restart algorithm was applied to identify the prioritizations of these DEGs when considering their relationship with FSCN1. These analyses based on PPI network have greatly expanded our comprehension of the mRNA expression profile following fascin knockdown to future examine the roles and mechanisms of fascin action.

Interacting network of Hippo, Wnt/β-catenin and Notch signaling represses liver tumor formation

  • Kim, Wantae;Khan, Sanjoy Kumar;Yang, Yingzi
    • BMB Reports
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    • 제50권1호
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    • pp.1-2
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    • 2017
  • Acquiring a selective growth advantage by breaking the proliferation barrier established by gatekeeper genes is a centrally important event in tumor formation. Removal of the mammalian Hippo kinase Mst1 and Mst2 in hepatocytes leads to rapid hepatocellular carcinoma (HCC) formation, indicating that the Hippo signaling pathway is a critical gatekeeper that restrains abnormal growth in hepatocytes. By rigorous genetic approaches, we identified an interacting network of the Hippo, Wnt/${\beta}$-catenin and Notch signaling pathways that control organ size and HCC development. We found that in hepatocytes, the loss of Mst1/2 leads to the activation of Notch signaling, which forms a positive feedback loop with Yap/Taz (transcription factors controlled by Mst1/2). This positive feedback loop results in severe liver enlargement and rapid HCC formation. Blocking the Yap/Taz-Notch positive feedback loop by Notch inhibition in vivo significantly reduced the Yap/Taz activities, hepatocyte proliferation and tumor formation. Furthermore, we uncovered a surprising inhibitory role of Wnt/${\beta}$-catenin signaling to Yap/Taz activities, which are important in tumor initiation. Genetic removal of ${\beta}$-catenin in the liver of the Mst1/2 mutants significantly accelerates tumoriogenesis. Therefore, Wnt/${\beta}$-catenin signaling, known for its oncogenic property, exerts an unexpected function in restricting Yap/Taz and Notch activities in HCC initiation. The molecular interplay between the three signaling pathways identified in our study provides new insights in developing novel therapeutic strategies to treat liver tumors.

1,3-Dibenzyl-5-Fluorouracil Prevents Ovariectomy-Induced Bone Loss by Suppressing Osteoclast Differentiation

  • Hyoeun Jeon;Jungeun Yu;Jung Me Hwang;Hye-Won Park;Jiyeon Yu;Zee-Won Lee;Taesoo Kim;Jaerang Rho
    • IMMUNE NETWORK
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    • 제22권5호
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    • pp.43.1-43.12
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    • 2022
  • Osteoclasts (OCs) are clinically important cells that resorb bone matrix. Accelerated bone destruction by OCs is closely linked to the development of metabolic bone diseases. In this study, we screened novel chemical inhibitors targeting OC differentiation to identify drug candidates for metabolic bone diseases. We identified that 1,3-dibenzyl-5-fluorouracil, also named OCI-101, is a novel inhibitor of osteoclastogenesis. The formation of multinucleated OCs is reduced by treatment with OCI-101 in a dose-dependent manner. OCI-101 inhibited the expression of OC markers via downregulation of receptor activator of NF-κB ligand and M-CSF signaling pathways. Finally, we showed that OCI-101 prevents ovariectomy-induced bone loss by suppressing OC differentiation in mice. Hence, these results demonstrated that OCI-101 is a good drug candidate for treating metabolic bone diseases.

Pathway Crosstalk Analysis Based on Protein-protein Network Analysis in Ovarian Cancer

  • Pan, Xiao-Hua
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권8호
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    • pp.3905-3909
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    • 2012
  • Ovarian cancer is the fifth leading cause of cancer death in women aged 35 to 74 years. Although there are several popular hypothesis of ovarian cancer pathogenesis, the genetic mechanisms are far from being clear. Recently, systems biology approaches such as network-based methods have been successfully applied to elucidate the mechanisms of diseases. In this study, we constructed a crosstalk network among ovarian cancer related pathways by integrating protein-protein interactions and KEGG pathway information. Several significant pathways were identified to crosstalk with each other in ovarian cancer, such as the chemokine, Notch, Wnt and NOD-like receptor signaling pathways. Results from these studies will provide the groundwork for a combination therapy approach targeting multiple pathways which will likely be more effective than targeting one pathway alone.