Sunil Kim
Hanyang University
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Featured researches published by Sunil Kim.
Infection and Immunity | 2010
Young Mee Yoon; Jin Young Lee; Doyoung Yoo; Young-Suk Sim; Young-Jeon Kim; Yu-Kyoung Oh; Ju Seop Kang; Sunil Kim; Joo Sung Kim; Jung Mogg Kim
ABSTRACT Enterotoxigenic Bacteroides fragilis (ETBF) produces an approximately 20-kDa heat-labile enterotoxin (BFT) that plays an essential role in mucosal inflammation. Although spontaneous disappearance of ETBF infection is common, little information is available on regulated expression of antibacterial factors in response to BFT stimulation. This study investigates the role of BFT in human β-defensin 2 (hBD-2) induction from intestinal epithelial cells. Stimulation of HT-29 and Caco-2 intestinal epithelial cell lines with BFT resulted in the induction of hBD-2. Activation of a reporter gene for hBD-2 was dependent on the presence of NF-κB binding sites. In contrast, suppression of AP-1 did not affect hBD-2 expression in BFT-stimulated cells. Inhibition of p38 mitogen-activated protein kinase (MAPK) using SB203580 and small interfering RNA (siRNA) transfection resulted in a significant reduction in BFT-induced IκB kinase (IKK)/NF-κB activation and hBD-2 expression. Our results suggest that a pathway including p38 MAPK, IKK, and NF-κB activation is required for hBD-2 induction in intestinal epithelial cells exposed to BFT, and may be involved in the host defense following infection with ETBF.
Laboratory Investigation | 2009
Jung Mogg Kim; Hyoun Woo Kang; Mi Yeon Cha; Doyoung Yoo; Nayoung Kim; In-Kyoung Kim; Jeounghun Ku; Sunil Kim; Sang-Ho Ma; Hyun Chae Jung; In Sung Song; Joo Sung Kim
We already showed that the plant sterol guggulsterone has been reported to inhibit nuclear factor-κB (NF-κB) signaling in intestinal epithelial cells (IECs) and to attenuate dextran sulfate sodium (DSS)-induced colitis. This study investigates the anti-inflammatory effects of novel guggulsterone derivatives on IEC and preventive and therapeutic murine models of DSS-induced colitis. Novel guggulsterone derivates with high lipophilicity were designed and four derivates, including GG-46, GG-50B, GG-52, and GG-53, were synthesized. Two guggulsterone derivatives, GG-50B and GG-52, significantly inhibited the activated NF-κB signals and the upregulated expression of interleukin-8 (IL-8) in COLO 205 cells stimulated with tumor necrosis factor-α (TNF-α). Pretreatment with GG-50B and GG-52 attenuated the increased IκB kinase (IKK) and IκBα phsophorylation induced by TNF-α. In preventive and therapeutic models of murine colitis, administration of GG-52 significantly reduced the severity of DSS-induced colitis, as assessed by disease activity index, colon length, and histology. In contrast, GG-50B did not show a significant reduction in the colitis severity. Moreover, the efficacy on attenuating colitis by GG-52 was comparable to that by sulfasalazine or prednisolone. These results indicate that the novel guggulsterone derivative GG-52 blocks NF-κB activation in IEC and ameliorates DSS-induced acute murine colitis, which suggests that GG-52 is a potential therapeutic agent for the treatment of inflammatory bowel diseases.
International Journal of Clinical and Experimental Hypnosis | 2007
Jun-Seok Lee; David Spiegel; Saebyul Kim; Jang-Han Lee; Sunil Kim; Byung-Hwan Yang; Joonho Choi; Yong-Chul Kho; Jung-Hyun Nam
Fractal analysis was applied to study the trends of EEG signals in the hypnotic condition. The subjects were 19 psychiatric outpatients. Hypnotizability was measured with the Hypnotic Induction Profile (HIP). Fifty-four sets of EEG data were analyzed by detrended fluctuation analysis (DFA), a well-established fractal analysis technique. The scaling exponents, which are the results of fractal analysis, are reduced toward white noise during the hypnotic condition, which differentiates the hypnotic condition from the waking condition. Further, the decrease in the scaling exponents during hypnosis was solely associated with the eye-roll sign within specific cortical areas (F3, C4, and O1/2) closely related to eye movements and attention. In conclusion, the present study has found that the application of the fractal analysis technique can demonstrate the electrophysiological correlations with hypnotic influence on cerebral activity.
Clinical and Experimental Immunology | 2009
Jung-Mogg Kim; D.H. Lee; J. Kim; Jin-Seok Lee; Hye-Yeon Park; Y.-J. Kim; Yu-Kyoung Oh; Hyun-Do Jung; Sunil Kim
Enterotoxin produced by enterotoxigenic Bacteroides fragilis (BFT) has been associated with mucosal inflammation and diarrhoeal diseases. In this study, the anti‐inflammatory molecular mechanism of 5,7‐dihydroxy‐3,4,6‐trimethoxyflavone (eupatilin) was characterized in an HT‐29 intestinal epithelial cell line stimulated with BFT. Pre‐treatment of HT‐29 cells with eupatilin decreased the production significantly of both interleukin (IL)‐8 and prostaglandin E2 induced by BFT in a dose‐dependent manner. BFT‐activated nuclear factor‐kappaB (NF‐κB) signals in HT‐29 cells and pretreatment with eupatilin suppressed NF‐κB activation that resulted in the significant inhibition of IL‐8 and cyclo‐oxygenase‐2 expression. BFT‐induced phosphorylation of both IκBα and IκB kinase (IKK) signals was prevented in eupatilin‐pretreated HT‐29 cells. Transfection of siRNA for IKK‐α and IKK‐β decreased the production of IL‐8 and prostaglandin E2; however, the transfection of IKK‐β siRNA showed a more significant reduction of BFT‐induced IκBα phosphorylation compared with that of IKK‐α siRNA. In addition, herbimycin A, a specific inhibitor of heat shock protein 90 (Hsp90), decreased the BFT‐induced activation of IKK and NF‐κB, suggesting that Hsp90 is associated with a pathway of IKK‐NF‐κB‐IL‐8/cyclo‐oxygenase‐2 gene signalling. Furthermore, eupatilin dissociated the complex between Hsp90 and IKK‐γ in BFT‐stimulated HT‐29 cells. These results suggest that eupatilin can suppress the NF‐κB signalling pathway by targeting the Hsp90‐IKK‐γ complex in intestinal epithelial cells and may attenuate BFT‐induced inflammatory responses.
European Journal of Immunology | 2010
Jung Mogg Kim; Joo Sung Kim; Jin Young Lee; Young-Suk Sim; Young-Jeon Kim; Yu-Kyoung Oh; Ho Joo Yoon; Ju Seop Kang; Jeehee Youn; Nayoung Kim; Hyun Chae Jung; Sunil Kim
Although Helicobacter pylori infections of the gastric mucosa are characterized by the infiltration of inflammatory cells such as eosinophils, the responses of eosinophils to H. pylori vacuolating cytotoxin (VacA) have not been fully elucidated. This study investigates the role of VacA in the apoptosis of human eosinophils. We treated human eosinophils with purified H. pylori VacA and observed that induction of apoptosis is a relatively late event. Expression of cellular inhibitor of apoptosis protein (c‐IAP)‐2 was upregulated during the early period of VacA stimulation, and transfection with c‐IAP2 siRNA augmented apoptotic cell death. VacA caused the translocation of cytoplasmic Bax to the mitochondria and increased cytochrome c release from mitochondria in eosinophils. Transfection of an EoL‐1 eosinophil cell line with Bax siRNA decreased the release of cytochrome c and DNA fragmentation. Furthermore, apoptosis facilitated by Bax and cytochrome c was primarily regulated by p38 MAPK in VacA‐treated eosinophils. These results suggest that the exposure of human eosinophils to H. pylori VacA induces the early upregulation of c‐IAP2 and a relatively late apoptotic response, with the apoptosis progressing through a sequential pathway that includes p38 MAPK activation, Bax translocation, and cytochrome c release.
Journal of Pharmaceutical Investigation | 2010
Sang Myoung Noh; Da-Eui Park; Saewon Im; Sunil Kim; Young Bong Kim; Yu-Kyoung Oh
We aimed to evaluate the effect of temperature, pH, and light conditions on the stability of porcine placental extract (PPE)-loaded liposomes with different surface charges. The size distribution profiles and in vitro release patterns were investigated by dynamic light scattering method and spectrophotometry. The stability of PPE-loaded liposomes was affected by the surface charges of the liposomes. As compared to neutral and anionic liposomes, cationic liposome formulations showed significantly lower physical stability. At the test storage conditions of different temperatures and pHs, the mean sizes of cationic PPE-loaded liposomes substantially increased. In contrast, neutral and anionic liposomes did not reveal significant changes in mean sizes upon various storage conditions. The neutral and anionic liposomes showed no significant differences in the release profiles of PPE after storage at various temperatures and pHs. Our results indicate that anionic and neutral liposome compositions might be more suitable for the formulations of PPE providing the higher stability.
Arthroscopy | 2001
Tae-Soo Park; Dong-Woo Park; Sunil Kim; Tae-Hyoung Kweon
electronic imaging | 2017
Wontaek Seo; Hoon Song; Jungkwuen An; Juwon Seo; Gee-young Sung; Yun-Tae Kim; Chil-Sung Choi; Sunil Kim; Ho-Jung Kim; Yongkyu Kim; Young Keun Kim; Yunhee Kim; Hong-Seok Lee; Sungwoo Hwang
SID Symposium Digest of Technical Papers | 2018
Jungkwuen An; Bongsu Shin; Chang-Kun Lee; Chil-Sung Choi; Chorong Yoo; Gee-young Sung; Ho-Jung Kim; Hoon Song; Jaeseung Chung; Juwon Seo; Kanghee Won; Sunghoon Lee; Sunil Kim; Wontaek Seo; Yongkyu Kim; Young Ok Kim; Yun-Tae Kim; Hong-Seok Lee; Duck-Hyung Lee
Applied Optics | 2018
Young Keun Kim; Kanghee Won; Yunhee Kim; Jungkuen An; Hoon Song; Sunil Kim; Chil-Sung Choi; Hong-Seok Lee