Activation of toll-like receptor 3 attenuates alcoholic liver injury by stimulating Kupffer cells and stellate cells to produce interleukin-10 in mice

Byun, J.S.,Suh, Y.G.,Yi, H.S.,Lee, Y.S.,Jeong, W.I. Elsevier Science Publishers 2013 Journal of hepatology Vol.58 No.2

Background & Aims: The important function of toll-like receptor (TLR) 4 in Kupffer cells and hepatic stellate cells (HSCs) has been well documented in alcoholic liver injury. However, little is known about the role of TLR3. Thus, we tested whether TLR3 activation in HSCs and Kupffer cells could attenuate alcoholic liver injury in vivo, and investigated its possible mechanism in vitro. Methods: Alcoholic liver injury was achieved by feeding wild type (WT), TLR3 knockout (TLR3<SUP>-/-</SUP>) and interleukin (IL)-10<SUP>-/-</SUP> mice with high-fat diet plus binge ethanol drinking for 2weeks. To activate TLR3, polyinosinic-polycytidylic acid (poly I:C) was injected into mice. For in vitro studies, HSCs and Kupffer cells were isolated and treated with poly I:C. Results: In WT mice, poly I:C treatment reduced alcoholic liver injury and fat accumulation by suppressing nuclear factor-κB activation and sterol response element-binding protein 1c expression in the liver. In addition, freshly isolated HSCs and Kupffer cells from poly I:C-treated mice showed enhanced expression of IL-10 compared to controls. Infiltrated macrophage numbers and the expression of tumor necrosis factor-α, monocyte chemoattractant protein-1 and IL-6 on these cells were decreased after poly I:C treatment. In vitro, poly I:C treatment enhanced the expression of IL-10 via a TLR3-dependent mechanism in HSCs and Kupffer cells. Finally, the protective effects of poly I:C on alcoholic liver injury were diminished in TLR3<SUP>-/-</SUP> and IL-10<SUP>-/-</SUP> mice. Conclusions: TLR3 activation ameliorates alcoholic liver injury via the stimulation of IL-10 production in HSCs and Kupffer cells. TLR3 could be a novel therapeutic target for the treatment of alcoholic liver injury.

Effects of dextrorotatory morphinans on brain Na⁺ channels expressed in Xenopus oocytes

Lee, J.H.,Shin, E.J.,Jeong, S.M.,Lee, B.H.,Yoon, I.S.,Lee, J.H.,Choi, S.H.,Kim, Y.H.,Pyo, M.K.,Lee, S.M.,Chae, J.S.,Rhim, H.,Oh, J.W.,Kim, H.C.,Nah, S.Y. North-Holland ; Elsevier Science Ltd 2007 european journal of pharmacology Vol.564 No.1

We previously demonstrated that dextromethorphan (DM; 3-methoxy-17-methylmorphinan) analogs have neuroprotective effects. Here, we investigated the effects of DM, three of its analogs (DF, 3-methyl-17-methylmorphinan; AM, 3-allyloxy-17-methoxymorphian; and CM, 3-cyclopropyl-17-methoxymorphinan) and one of its metabolites (HM; 3-methoxymorphinan), on Na<SUP>+</SUP> channel activity. We used the two-microelectrode voltage-clamp technique to test the effects of DM, DF, AM, CM and HM on Na<SUP>+</SUP> currents (I<SUB>Na</SUB>) in Xenopus oocytes expressing cRNAs encoding rat brain Nav1.2 α and β1 or β2 subunits. In oocytes expressing Na<SUP>+</SUP> channels, DM, DF, AM and CM, but not HM, induced tonic and use-dependent inhibitions of peak I<SUB>Na</SUB> following low- and high-frequency stimulations. The order of potency for the inhibition of peak I<SUB>Na</SUB> was AM-CM > DM=DF. The DM, DF, AM and CM-induced tonic inhibitions of peak I<SUB>Na</SUB> were voltage-dependent, dose-dependent and reversible. The IC<SUB>50</SUB> values for DM, DF, AM and CM were 116.7+/-14.9, 175.8+/-16.9, 38.6+/-15.5, and 42.5+/-8.5 μM, respectively. DM and its analogs did not affect the steady-state activation and inactivation voltages. AM and CM, but not DM and DF, inhibited the plateau I<SUB>Na</SUB> more effectively than the peak I<SUB>Na</SUB> in oocytes expressing inactivation-deficient I1485Q-F1486Q-M1487Q (IFMQ3) mutant channels; the IC<SUB>50</SUB> values for AM and CM in this system were 8.4+/-1.3 and 8.7+/-1.3 μM, respectively, for the plateau I<SUB>Na</SUB> and 43.7+/-5.9 and 32.6+/-7.8 μM, respectively, for the peak I<SUB>Na</SUB>. These results collectively indicate that DM and its analogs could be novel Na<SUP>+</SUP> channel blockers acting on the resting and open states of brain Na<SUP>+</SUP> channels.

¹³¹I-labeled chitosan hydrogels for radioembolization: A preclinical study in small animals

Hwang, H.,Kim, K.I.,Kwon, J.,Kim, B.S.,Jeong, H.S.,Jang, S.J.,Oh, P.S.,Park, H.S.,Lim, S.T.,Sohn, M.H.,Jeong, H.J. Pergamon Press 2017 Nuclear medicine and biology Vol.52 No.-

<P>Advances in knowledge: Transarterial embolization is a conceivable treatment option for patients with inoperable liver cancer to mitigate the disease progression. Recently, we have developed chitosan-based hydrogel microparticles. In the present study, the hydrogel microparticles were radiolabeled with I-131 for treatment of liver cancer. Our results demonstrated that a hepatic arterial injection of I-125 -labeled Chi resulted in substantial liver accumulation, which was accompanied by virtually no extrahepatic deposition. The results of the present study also showed that administration of I-131 Chi markedly suppressed tumor growth, compared to controls and to animals receiving unlabeled Chi. I-131 -labeled chitosan hydrogel microparticles represent a new therapeutic approach for treatment of liver cancer. (C) 2017 Elsevier Inc. All rights reserved.</P>

REAL HYPERSURFACES IN COMPLEX TWO-PLANE GRASSMANNIANS WITH GENERALIZED TANAKA-WEBSTER [unknown]-PARALLEL SHAPE OPERATOR

Jeong, I.,Lee, H.,Suh, Y.J. World Scientific 2012 International journal of geometric methods in mode Vol.9 No.4

<P>In a paper due to [I. Jeong, H. Lee and Y. J. Suh, Real hypersurfaces in complex two-plane Grassmannians with generalized Tanaka-Webster parallel shape operator, Kodai Math. J. 34 (2011) 352-366] we have shown that there does not exist a hypersurface in G(2)(Cm+2) with parallel shape operator in the generalized Tanaka-Webster connection (see [N. Tanaka, On non-degenerate real hypersurfaces, graded Lie algebras and Cartan connections, Japan J. Math. 20 (1976) 131-190; S. Tanno, Variational problems on contact Riemannian manifolds, Trans. Amer. Math. Soc. 314(1) (1989) 349-379]). In this paper, we introduce a new notion of generalized Tanaka-Webster D-perpendicular to-parallel for a hypersurface M in G(2)(Cm+2), and give a characterization for a tube around a totally geodesic HPn in G(2)(Cm+2) where m = 2n.</P>

Low-cost electrospun WC/C composite nanofiber as a powerful platinum-free counter electrode for dye sensitized solar cell

Jeong, I.,Lee, J.,Vincent Joseph, K.L.,Lee, H.I.,Kim, J.K.,Yoon, S.,Lee, J. Elsevier 2014 Nano energy Vol.9 No.-

Tungsten carbide/carbon (WC/C) composite nanofibers were successfully prepared through electrospinning followed by a one-step heat treatment using in-situ carburization. The WC/C nanofibers were applied to low-cost and platinum-free counter electrodes for dye sensitized solar cells (DSSCs), and their catalytic activities were investigated and compared to platinum (Pt) CEs for triiodide/iodide (I<SUB>3</SUB><SUP>-</SUP>/I<SUP>-</SUP>) as well as organic disulfide/thiolate (T<SUB>2</SUB>/T<SUP>-</SUP>) electrolytes. When WC/C nanofibers are used as the CE catalyst in iodine electrolytes, the DSSCs exhibited a power conversion efficiency (PCE) of 7.77%, corresponding to 96% of that of Pt CEs. In the case of T<SUB>2</SUB>/T<SUP>-</SUP> redox couples, the DSSCs based on WC/C nanofibers achieved PCE of 5.85%, which is almost twice that of Pt (3.07%). The high catalytic activities of WC/C nanofibers are attributed to synergetic effects from the combination of catalytically active WC and one-dimensional (1D) conductive carbon acting as an efficient charge transport pathway. In addition, spray-coated WC/C nanofiber CE films have a three-dimensional porous network, enhancing the permeation of the electrolyte into the CE film and the diffusion of redox couples. The electrospinning process used for the synthesis of the WC/C nanofibers is facile and scalable and is therefore promising for the commercialization of DSSCs.

Ischemic brain imaging using fluorescent gold nanoprobes sensitive to reactive oxygen species

Hyun, H.,Lee, K.,Min, K.H.,Jeon, P.,Kim, K.,Jeong, S.Y.,Kwon, I.C.,Park, T.G.,Lee, M. Elsevier Science Publishers 2013 Journal of controlled release Vol.170 No.3

Fluorescein-labeled hyaluronic acids (HA) were immobilized on gold nanoparticles for reactive oxygen species (ROS) detection. The efficacy of HA immobilized gold nanoparticles (HHAuNPs) was evaluated in a stroke animal model. The stroke rat model was produced by transient middle cerebral artery occlusion (MCAO), which induced transient ischemia and reperfusion (I/R) in the brain. The increase of ROS in the I/R brain was confirmed by TBARS assay with the brain extracts. For brain imaging, HHAuNPs were injected into the rat brain 1h before transient MCAO. Five hours after the injection, the rats were sacrificed and the brains were subjected to imaging analysis. The results showed that stronger signals were detected in the I/R brains than in the normal brains. To identify the time window for effective detection of ROS, HHAuNPs were injected into the post-ischemic rat brains at various time points. The results showed that ROS level reached a maximum at 24h after the transient MCAO. Also, a live imaging study was performed with HHAuNPs in the normal and I/R animals. The results confirmed that ROS level increased in the I/R animal group with time, while the signal was decreased in the normal animal group. Together, our results suggest that HHAuNPs may be useful to monitor ROS level in the ischemic brain and to identify the infarct areas in ischemic brains for the treatment of stroke.

Genetic diversity of the VP7, VP4 and VP6 genes of Korean porcine group C rotaviruses

Jeong, Y.J.,Matthijnssens, J.,Kim, D.S.,Kim, J.Y.,Alfajaro, M.M.,Park, J.G.,Hosmillo, M.,Son, K.Y.,Soliman, M.,Baek, Y.B.,Kwon, J.,Choi, J.S.,Kang, M.I.,Cho, K.O. Elsevier Scientific Pub. Co 2015 Veterinary microbiology Vol.176 No.1

Porcine group C rotaviruses (RVCs) are considered important pathogens due to their economic impact on pig industry and may also cross the host species barrier toward humans. Unlike RVA, however, genetic and phylogenetic data on RVCs from pigs and other host species are scarce. In the present study, full-length ORF sequences of 26 VP7, 9 VP4 and 9 VP6 genes of Korean porcine RVC strains were compared with those of other known RVC strains by phylogenetic analyses and pairwise identity frequency graphs. Applying the established 85% nucleotide identity cut-off value for RVC VP7 classification, the 26 Korean porcine RVC strains belonged to the G1, G3, G6 and G7 genotypes. Although more complete RVC VP4 sequences are warranted before a definitive cut-off value could be determined, a provisional 83% nucleotide cut-off value proposed for RVC VP4 classification resulted in 7 P-genotypes, 5 of which possessed porcine RVC strains. A 90% nucleotide cut-off value for VP6 divided RVC strains into 7 I-genotypes, 5 of which had porcine RVC strains. G/P/I-genotype comparisons suggested the occurrence of rather frequent reassortment events among Korean porcine RVC strains, and strong geographical differences in the distribution of RVC G-genotypes worldwide. Our data indicate that a large genetic diversity exists among porcine RVC strains. For the final genotype determination of each gene segment, more intensified epidemiological studies on animal and human RVC strains throughout the world are needed.

Electronic and steric effects controlling efficiencies of photoaddition reactions of fullerene C₆₀ with N-α-trimethylsilyl-N-alkyl-N-benzylamines

Jeong, H.C.,Lim, S.H.,Sohn, Y.,Kim, Y.I.,Jang, H.,Cho, D.W.,Mariano, P.S. Pergamon Press ; Elsevier Science Ltd 2017 Tetrahedron letters: the international organ for t Vol.58 No.10

Single electron transfer (SET)-promoted photoaddition reactions between fullerene C<SUB>60</SUB> and both various alkyl (Me, Et, i-Pr, t-Bu)- and para-substituted (p-Me, p-OMe, p-F, p-CF<SUB>3</SUB>) arene ring containing, N-α-trimethylsilyl-N-alkyl-N-benzylamines were explored to gain information about photoproduct profiles and how the electronic and steric nature of the amine substrates influence reaction efficiencies. The results show that visible light (λ>540nm) irradiation of 10% EtOH-toluene solutions containing C<SUB>60</SUB> and N-α-trimethylsilyl-N-alkyl-N-benzylamines produce 1-aminomethyl-1,2-dihydrofullerenes as a sole photoproduct. In addition, SET-promoted photoaddition reactions of unsubstituted and para-electron donating group substituted arene ring containing N-α-trimethylsilyl-N-alkyl-N-benzylamines take place to give photoproducts more efficiently than those containing para-electron withdrawing group substituted arene rings. Moreover, although steric factors are less significant than the electronic nature of the amine substrates in governing reaction efficiencies, sterics do play a significant role in photoreactions of electron deficient amine substrates.

Modification of Schottky Barrier Properties of Ti/p-type InP Schottky Diode by Polyaniline (PANI) Organic Interlayer

P. R. Sekhar Reddy,V. Janardhanam,I. Jyothi,Shim-Hoon Yuk,V. Rajagopal Reddy,Jae-Chan Jeong,Sung-Nam Lee,Chel-Jong Choi 대한전자공학회 2016 Journal of semiconductor technology and science Vol.16 No.5

The electrical properties of Ti/p-type InP Schottky diodes with and without polyaniline (PANI) interlayer was investigated using current–voltage (I–V) and capacitance–voltage (C–V) measurements. The barrier height of Ti/p-type InP Schottky diode with PANI interlayer was higher than that of the conventional Ti/p-type InP Schottky diode, implying that the organic interlayer influenced the space-charge region of the Ti/p-type InP Schottky junction. At higher voltages, the current transport was dominated by the trap free space-charge-limited current and trap-filled space-charge-limited current in Ti/p-type InP Schottky diode without and with PANI interlayer, respectively. The domination of trap filled space-charge-limited current in Ti/p-type InP Schottky diode with PANI interlayer could be associated with the traps originated from structural defects prevailing in organic PANI interlayer.

각종 버섯류로부터 안지오텐신 전환효소 저해제의 탐색

이대형 ( I Daehyeong ),김재호 ( Kim Jae Ho ),정종천 ( Jeong Jong Cheon ),공원식 ( Gong Won Sig ),유영복 ( Yu Yeong Bog ),박정식 ( Bak Jeong Sig ),유창현 ( Yu Changhyeon ),이종수 ( Lee Jongsu ) 한국균학회 2003 韓國菌學會誌 Vol.31 No.3