• Title/Summary/Keyword: signaling chemical

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Solution Structure of the Cytoplasmic Domain of Syndecan-3 by Two-dimensional NMR Spectroscopy

  • Yeo, In-Young;Koo, Bon-Kyung;Oh, Eok-Soo;Han, Inn-Oc;Lee, Weon-Tae
    • Bulletin of the Korean Chemical Society
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    • v.29 no.5
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    • pp.1013-1017
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    • 2008
  • Syndecan-3 is a cell-surface heparan sulfate proteoglycan, which performs a variety of functions during cell adhension process. It is also a coreceptor for growth factor, mediating cell-cell and cell-matrix interaction. Syndecan-3 contains a cytoplasmic domain potentially associated with the cytoskeleton. Syndecan-3 is specifically expressed in neuron cell and has related to neuron cell differentiation and development of actin filament in cell migration. Syndecans each have a unique, central, and variable (V) region in their cytoplasmic domains. And that region of syndecan-3 may modulate the interactions of the conserved C1 regions of the cytoplasmic domains by tyrosine phosphorylation. Cytoplasmic domain of syndecan-3 has been synthesized for NMR structural studies. The solution structure of syndecan-3 cytoplasmic domain has been determined by two-dimensional NMR spectroscopy and simulated-annealing calculation. The cytoplasmic domain of the syndecan proteins has a tendency to form a dimmer conformation with a central cavity, however, that of syndecan-3 demonstrated a monomer conformation with a flexible region near C-terminus. The structural information might add knowledge about the structure-function relationships among syndecan proteins.

In vitro Interaction of Recombinantly Expressed Kringle 5 (rK5) with Ras Guanine Nucleotide Dissociation Stimulator-like Factor (Rgl2)

  • Lee, Jung-Whoi;Kim, Sun-Hee;Park, Yong-Sung;Woo, Je-Wan;Lim, Dong-Yeol;Lee, Kyung-Hee
    • Bulletin of the Korean Chemical Society
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    • v.25 no.12
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    • pp.1863-1868
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    • 2004
  • Kringle 5 (K5), located outside of angiostain (K1-4) in human plasminogen, displays more potent antiangiogenic activity on endothelial cell proliferation than angiostatin itself. Using a yeast two-hybrid system in vivo, we have recently identified Rgl2 (guanine nucleotide dissociation stimulator (RalGDS)-like factor 2) as a binding protein of human K5. In order to confirm in vitro protein interaction between K5 and Rgl2, we developed bacterial recombinant expression systems for them. K5 and Rgl2 proteins were expressed in high yields and purified into pure forms with His tags and GST fusion, respectively. GST-pull down experiments clearly demonstrated that K5 interacts specifically with Rgl2 in vitro. These results indicate that Rgl2 functions as a receptor protein for K5 in vitro as well as in vivo, leading to anti-angiogenesis through regulating Ras signaling pathways.

Generation of novel hyaluronic acid biomaterials for study of pain in third molar intervention: a review

  • Shuborna, Nadia Sultana;Chaiyasamut, Teeranut;Sakdajeyont, Watus;Vorakulpipat, Chakorn;Rojvanakarn, Manus;Wongsirichat, Natthamet
    • Journal of Dental Anesthesia and Pain Medicine
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    • v.19 no.1
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    • pp.11-19
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    • 2019
  • Hyaluronic acid (HA) has long been studied in diverse applications. It is a naturally occurring linear polysaccharide in a family of unbranched glycosaminoglycans, which consists of repeating di-saccharide units of N-acetyl-D-glucosamine and D-glucuronic acid. It is almost ubiquitous in humans and other vertebrates, where it participates in many key processes, including cell signaling, tissue regeneration, wound healing, morphogenesis, matrix organization, and pathobiology. HA is biocompatible, biodegradable, muco-adhesive, hygroscopic, and viscoelastic. These unique physico-chemical properties have been exploited for several medicinal purposes, including recent uses in the adjuvant treatment for chronic inflammatory disease and to reduce pain and accelerate healing after third molar intervention. This review focuses on the post-operative effect of HA after third molar intervention along with its various physio-chemical, biochemical, and pharmaco-therapeutic uses.

Red ginseng (Panax ginseng Meyer) oil: A comprehensive review of extraction technologies, chemical composition, health benefits, molecular mechanisms, and safety

  • Truong, Van-Long;Jeong, Woo-Sik
    • Journal of Ginseng Research
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    • v.46 no.2
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    • pp.214-224
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    • 2022
  • Red ginseng oil (RGO), rather than the conventional aqueous extract of red ginseng, has been receiving much attention due to accumulating evidence of its functional and pharmacological potential. In this review, we describe the key extraction technologies, chemical composition, potential health benefits, and safety of RGO. This review emphasizes the proposed molecular mechanisms by which RGO is involved in various bioactivities. RGO is mainly produced using organic solvents or supercritical fluid extraction, with the choice of method greatly affecting the yield and quality of the end products. RGO contains a high unsaturated fatty acid levels along with considerable amounts of lipophilic components such as phytosterols, tocopherols, and polyacetylenes. The beneficial health properties of RGO include cellular defense, antioxidation, anti-inflammation, anti-apoptosis, chemoprevention, hair growth promotion, and skin health improvement. We propose several molecular mechanisms and signaling pathways that underlie the bioactivity of RGO. In addition, RGO is regarded as safe and nontoxic. Further studies on RGO must focus on a deeper understanding of the underlying molecular mechanisms, composition-functionality relationship, and verification of the bioactivities of RGO in clinical models. This review may provide useful information in the development of RGO-based products in nutraceuticals, functional foods, and functional cosmetics.

Improved Ultrastructural Preservation of Retinal Cells in Drosophila melanogaster (초고압동결장치를 이용한 초파리 레티나 세포의 향상된 미세구조)

  • Mun, Ji-Young;Park, Se-Jin;Han, Sung-Sik
    • Applied Microscopy
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    • v.37 no.3
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    • pp.175-183
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    • 2007
  • The Drosophila retinal cell is widely used to study cell development and cell signaling processes. In the past decades, conventional chemical fixation had been used to study the structure of retinal cells in Droscphila. Rapid freezing methods are superior to chemical fixation methods due to their fixation speed. Some Drosophila tissues, such as the eyes, should not be freezed due to their surrounding cuticle layer. Therefore, in the case of the Drosophila retina, the benefits of high pressure freezing and freeze substitution (HPF-FS) had not been verified. In this study, a retinal cell from Drosophila melanogaster had been studied by using the HPF-FS method. Compared to chemical fixation, the preservation of the cytoplasm in the HPF-FS sample was improved on the whole. The HPF-FS cell membranes were smoother than that of chemical fixation. In addition, HPF-FS preserved the mitochondria structures very well. These results of the present study suggest that HPF-FS is superior to other fixation methods for the preservation of the retinal cell structure.

Development of Inhibitors against TraR Quorum-Sensing System in Agrobacterium tumefaciens by Molecular Modeling of the Ligand-Receptor Interaction

  • Kim, Cheoljin;Kim, Jaeeun;Park, Hyung-Yeon;Park, Hee-Jin;Kim, Chan Kyung;Yoon, Jeyong;Lee, Joon-Hee
    • Molecules and Cells
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    • v.28 no.5
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    • pp.447-453
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    • 2009
  • The quorum sensing (QS) inhibitors that antagonize TraR, a receptor protein for N-3-oxo-octanoyl-L-homoserine lactones (3-oxo-C8-HSL), a QS signal of Agrobacterium tumefaciens were developed. The structural analogues of 3-oxo-C8-HSL were designed by in silico molecular modeling using SYBYL packages, and synthesized by the solid phase organic synthesis (SPOS) method, where the carboxamide bond of 3-oxo-C8-HSL was replaced with a nicotinamide or a sulfonamide bond to make derivatives of N-nicotinyl-L-homoserine lactones or N-sulfonyl-L-homoserine lactones. The in vivo inhibitory activities of these compounds against QS signaling were assayed using reporter systems and compared with the estimated binding energies from the modeling study. This comparison showed fairly good correlation, suggesting that the in silico interpretation of ligand-receptor structures can be a valuable tool for the pre-design of better competitive inhibitors. In addition, these inhibitors also showed anti-biofilm activities against Pseudomonas aeruginosa.

Anticancer Activity of Acanthopanax trifoliatus (L) Merr Extracts is Associated with Inhibition of NF-κB Activity and Decreased Erk1/2 and Akt Phosphorylation

  • Wang, Hua-Qian;Li, Dong-Li;Lu, Yu-Jing;Cui, Xiao-Xing;Zhou, Xiao-Fen;Lin, Wei-Ping;Conney, Allan H.;Zhang, Kun;Du, Zhi-Yun;Zheng, Xi
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.21
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    • pp.9341-9346
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    • 2014
  • Acanthopanax trifoliatus (L) Merr (AT) is commonly used as an herbal medicine and edible plant in some areas of China and other Asian countries. AT is thought to have anticancer effects, but potential mechanisms remain unknown. To assess the anticancer properties of AT, we exposed prostate cancer cells to AT extracts and assessed cell proliferation and signaling pathways. An ethanol extract of AT was suspended in water followed by sequential extraction with petroleum ether, ethyl acetate and n-butanol. PC-3 cells were treated with different concentrations of each extract and cell viability was determined by the MTT and trypan blue exclusion assays. The ethyl acetate extract of the ethanol extract had a stronger inhibitory effect on growth and a stronger stimulatory effect on apoptosis than any of the other extracts. Mechanistic studies demonstrated that the ethyl acetate extract suppressed the transcriptional activity of NF-${\kappa}B$, increased the level of caspase-3, and decreased the levels of phospho-Erk1/2 and phospho-Akt. This is the first report on the anticancer activity of AT in cultured human prostate cancer cells. The results suggest that AT can provide a plant-based medicine for the treatment or prevention of prostate cancer.

Regulation of Class II Bacteriocin Production by Cell-Cell Signaling

  • Quadri, Luis E.N.
    • Journal of Microbiology
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    • v.41 no.3
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    • pp.175-182
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    • 2003
  • Production of ribosomally synthesized antimicrobial peptides usually referred to as bacteriocins is an inducible trait in several gram positive bacteria, particularly in those belonging to the group of lactic acid bacteria. In many of these organisms, production of bacteriocins is inducible and induction requires secretion and extracellular accumulation of peptides that act as chemical messengers and trigger bacteriocin production. These inducer peptides are often referred to as autoinducers and are believed to permit a quorum sensing-based regulation of bacteriocin production. Notably, the peptides acting as autoinducers are dedicated peptides with or without antimicrobial activity or the bacteriocins themselves. The autoinducer-dependent induction of bacteriocin production requires histidine protein kinases and response regulator proteins of two-component signal transduction systems. The current working model for the regulation of class II bacteriocin production in lactic acid bacteria and the most relevant direct and indirect pieces of evidence supporting the model are discussed in this minireview.

Neurogenic pathways in remote ischemic preconditioning induced cardioprotection: Evidences and possible mechanisms

  • Aulakh, Amritpal Singh;Randhawa, Puneet Kaur;Singh, Nirmal;Jaggi, Amteshwar Singh
    • The Korean Journal of Physiology and Pharmacology
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    • v.21 no.2
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    • pp.145-152
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    • 2017
  • Remote ischemic preconditioning (RIPC) is an intrinsic phenomenon whereby 3~4 consecutive ischemia-reperfusion cycles to a remote tissue (non-cardiac) increases the tolerance of the myocardium to sustained ischemia-reperfusion induced injury. Remote ischemic preconditioning induces the local release of chemical mediators which activate the sensory nerve endings to convey signals to the brain. The latter consequently stimulates the efferent nerve endings innervating the myocardium to induce cardioprotection. Indeed, RIPC-induced cardioprotective effects are reliant on the presence of intact neuronal pathways, which has been confirmed using nerve resection of nerves including femoral nerve, vagus nerve, and sciatic nerve. The involvement of neurogenic signaling has been further substantiated using various pharmacological modulators including hexamethonium and trimetaphan. The present review focuses on the potential involvement of neurogenic pathways in mediating remote ischemic preconditioning-induced cardioprotection.

Potential roles of reactive oxygen species derived from chemical substances involved in cancer development in the female reproductive system

  • Kim, Soo-Min;Hwang, Kyung-A;Choi, Kyung-Chul
    • BMB Reports
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    • v.51 no.11
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    • pp.557-562
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    • 2018
  • Reactive oxygen species (ROS) are major sources of cellular oxidative stress. Specifically, cancer cells harbor genetic alterations that promote a continuous and elevated production of ROS. While such oxidative stress conditions could be harmful to normal cells, they facilitate cancer cell growth in multiple ways by causing DNA damage and genomic instability, and ultimately by reprogramming cancer cell metabolism. This review provides up to date findings regarding the roles of ROS generation induced by diverse biological molecules and chemicals in representative women's cancer. Specifically, we describe the cellular signaling pathways that regulate direct or indirect interactions between ROS homeostasis and metabolism within female genital cancer cells.