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Gwangju, South Korea

Kim H.J.,Korea Research Institute of Chemical Technology | Kim S.H.,Korea Research Institute of Chemical Technology | Yun J.-M.,Kwangju Womens University
Evidence-based Complementary and Alternative Medicine | Year: 2012

Diabetes is characterized by a proinflammatory state, and several inflammatory processes have been associated with both type 1 and type 2 diabetes and the resulting complications. High glucose levels induce the release of proinflammatory cytokines. Fisetin, a flavonoid dietary ingredient found in the smoke tree (Cotinus coggygria), and is also widely distributed in fruits and vegetables. Fisetin is known to exert anti-inflammatory effects via inhibition of the NF- B signaling pathway. In this study, we analyzed the effects of fisetin on proinflammatory cytokine secretion and epigenetic regulation, in human monocytes cultured under hyperglycemic conditions. Human monocytic (THP-1) cells were cultured under control (14.5 mmol/L mannitol), normoglycemic (NG, 5.5 mmol/L glucose), or hyperglycemic (HG, 20 mmol/L glucose) conditions, in the absence or presence of fisetin. Fisetin was added (3-10 M) for 48 h. While the HG condition significantly induced histone acetylation, NF- B activation, and proinflammatory cytokine (IL-6 and TNF- α) release from THP-1 cells, fisetin suppressed NF- B activity and cytokine release. Fisetin treatment also significantly reduced CBP/p300 gene expression, as well as the levels of acetylation and HAT activity of the CBP/p300 protein, which is a known NF- B coactivator. These results suggest that fisetin inhibits HG-induced cytokine production in monocytes, through epigenetic changes involving NF- B. We therefore propose that fisetin supplementation be considered for diabetes prevention. © 2012 Hye Joo Kim et al. Source


Kim H.J.,Korea Research Institute of Chemical Technology | Lee W.,Korea Institute of Science and Technology | Yun J.-M.,Kwangju Womens University
Phytotherapy Research | Year: 2014

Hyperglycemia is a key feature in diabetes. Hyperglycemia has been implicated as a major contributor to several complications of diabetes. High glucose levels induce the release of proinflammatory cytokines. Luteolin is a flavone isolated from celery, green pepper, perilla leaf, and chamomile tea. Luteolin has been reported to possess antimutagenic, antitumorigenic, antioxidant, and anti-inflammatory properties. In this study, we investigated the effects of luteolin on proinflammatory cytokine secretion and its underlying epigenetic regulation in high-glucose-induced human monocytes. Human monocytic (THP-1) cells were cultured under controlled (14.5mM mannitol), normoglycemic (NG, 5.5mM glucose), or hyperglycemic (HG, 20mM glucose) conditions, in the absence or presence of luteolin. Luteolin (3-10 μM) was added for 48 h. While hyperglycemic conditions significantly induced histone acetylation, NF-κB activation, and proinflammatory cytokine (IL-6 and TNF-á) release from THP-1 cells, luteolin suppressed NF-κB activity and cytokine release. Luteolin also significantly reduced CREB-binding protein/p300 (CBP/p300) gene expression, as well as the levels of acetylation and histone acetyltransferase (HAT) activity of the CBP/p300 protein, which is a known NF-κB coactivator. These results suggest that luteolin inhibits HG-induced cytokine production in monocytes, through epigenetic changes involving NF-κB. We therefore suggest that luteolin may be a potential candidate for the treatment and prevention of diabetes and its complications. Copyright © 2014 John Wiley & Sons, Ltd. Source


Lee C.-S.,Kwangju Womens University
International Journal of Security and its Applications | Year: 2015

The demanding in construction of the stand-alone networks and interconnection between convergence devices have led an increase in research on Mobile Ad-hoc Network and the application of Mobile Ad-hoc Network has been paid much attention as a Ubiquitous computing which is growing fast in the field of computer science. With performance both as hosts and routers, easy network configuration, and fast response, mobile nodes participating in Mobile Ad-hoc Network are suitable for Embedded computing but have vulnerable points, about lack of dynamic network topology due to mobility, network scalability, passive attacks, and active attacks which make it impossible to manage continuous security authentication service. In this study, hashed AODV routing is used to protect from counterfeiting messages by malicious nodes in the course of path finding and setting, and disguising misrouted messages as different mobile nodes and inputting them into the network. © 2015 SERSC. Source


Jeon S.,Hanyang University | Oh S.,LG Innotek | Kim H.H.,Kwangju Womens University | Kim H.,Hanyang University
Electronics Letters | Year: 2012

Proposed is a novel mobile handset antenna with a double planar inverted-E (PIE) feed structure that achieves a wide impedance bandwidth. The antenna is designed by inserting two branch capacitors in the feed structure of a conventional planar inverted-F antenna. In the lower and higher frequency bands, the proposed antenna has a very wide impedance bandwidth characteristic, from 698 to 990MHz, and from 1710 to 2170MHz under a voltage standing wave ratio of 3:1 with good efficiency. © 2012 The Institution of Engineering and Technology. Source


Yun J.-M.,Kwangju Womens University | Lasalle J.M.,University of California at Davis | Gong Q.,qzgong@ucdavis.edu
Human molecular genetics | Year: 2014

During postnatal development, neuronal activity controls the remodeling of initially imprecise neuronal connections through the regulation of gene expression. MeCP2 binds to methylated DNA and modulates gene expression during neuronal development and MECP2 mutation causes the autistic disorder Rett syndrome. To investigate a role for MeCP2 in neuronal circuit refinement and to identify activity-dependent MeCP2 transcription regulations, we leveraged the precise organization and accessibility of olfactory sensory axons to manipulation of neuronal activity through odorant exposure in vivo. We demonstrate that olfactory sensory axons failed to develop complete convergence when Mecp2 is deficient in olfactory sensory neurons (OSNs) in an otherwise wild-type animal. Furthermore, we demonstrate that expression of selected adhesion genes was elevated in Mecp2-deficient glomeruli, while acute odor stimulation in control mice resulted in significantly reduced MeCP2 binding to these gene loci, correlating with increased expression. Thus, MeCP2 is required for both circuitry refinement and activity-dependent transcriptional responses in OSNs. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com. Source

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