• Title/Summary/Keyword: $S_{N}2$ pathway

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MicroRNA expression profiling in the lungs of genetically different Ri chicken lines against the highly pathogenic avian influenza H5N1 virus

  • Sooyeon Lee;Suyeon Kang;Jubi Heo;Yeojin Hong;Thi Hao Vu;Anh Duc Truong;Hyun S Lillehoj;Yeong Ho Hong
    • Journal of Animal Science and Technology
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    • v.65 no.4
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    • pp.838-855
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    • 2023
  • The highly pathogenic avian influenza (HPAI) virus triggers infectious diseases, resulting in pulmonary damage and high mortality in domestic poultry worldwide. This study aimed to analyze miRNA expression profiles after infection with the HPAI H5N1 virus in resistant and susceptible lines of Ri chickens.For this purpose, resistant and susceptible lines of Vietnamese Ri chicken were used based on the A/G allele of Mx and BF2 genes. These genes are responsible for innate antiviral activity and were selected to determine differentially expressed (DE) miRNAs in HPAI-infected chicken lines using small RNA sequencing. A total of 44 miRNAs were DE after 3 days of infection with the H5N1 virus. Computational program analysis indicated the candidate target genes for DE miRNAs to possess significant functions related to cytokines, chemokines, MAPK signaling pathway, ErBb signaling pathway, and Wnt signaling pathway. Several DE miRNA-mRNA matches were suggested to play crucial roles in mediating immune functions against viral evasion. These results revealed the potential regulatory roles of miRNAs in the immune response of the two Ri chicken lines against HPAI H5N1 virus infection in the lungs.

The Effect of Carbon Monoxide on L-type Calcium Channel Currents in Human Intestinal Smooth Muscle Cells

  • Lim, In-Ja
    • The Korean Journal of Physiology and Pharmacology
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    • v.7 no.6
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    • pp.357-362
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    • 2003
  • Carbon monoxide (CO) is low molecular weight oxide gas that is endogenously produced under physiological conditions and interacts with another gas, nitric oxide (NO), to act as a gastrointestinal messenger. The aim of this study was to determine the effects of exogenous CO on L-type calcium channel currents of human jejunal circular smooth muscle cells. Cells were voltage clamped with 10 mM barium ($Ba^{2+}$) as the charge carrier, and CO was directly applied into the bath to avoid perfusion induced effects on the recorded currents. 0.2% CO was increased barium current ($I_{Ba}$) by $15{\pm}2$% ($mean{\pm}S.E.$, p<0.01, n=11) in the cells. To determine if the effects of CO on barium current were mediated through the cGMP pathway, cells were pretreated with 1-H-[1,2,4]oxadiazolo[4,3,-a]quinoxalin-1-one (ODQ, $10{mu}M$), a soluble guanylyl cyclase inhibitor, and exogenous CO (0.2%) had no effect on barium currents in the presence of ODQ ($2{\pm}1$% increase, n=6, p>0.05). CO mediates inhibitory neurotransmission through the nitric oxide pathway. Therefore, to determine if the effects of CO on L-calcium channels were also mediated through NO, cells were incubated with $N^G-nitro-L-arginine$ (L-NNA, 1 mM), a nitric oxide synthase inhibitor. After L-NNA pretreatment, 0.2 % CO did not increase barium current ($4{\pm}2$% increase, n=6, p>0.05). NO donor, SNAP ($20{\mu}M$) increased barium current by $13{\pm}2$% (n=6, p<0.05) in human jejunal smooth muscle cells. These data suggest that CO activates L-type calcium channels through NO/cGMP dependant mechanism.

Correlation of the Rates of Solvolyses of 4-Methylthiophene-2-carbonyl Chloride Using the Extended Grunwald-Winstein Equation

  • Choi, Ho-June;Koo, In-Sun
    • Bulletin of the Korean Chemical Society
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    • v.33 no.2
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    • pp.499-504
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    • 2012
  • The specific rates of sovolysis of 4-methylthiophene-2-carbonyl chloride (1) have been determined in 26 pure and binary solvents at $25.0^{\circ}C$. Product selectivities are reported for solvolyses of 1 in aqueous ethanol and methanol binary mixtures. Comparison of the specific rates of solvolyses of 1 with those for p-methoxybenzoyl chloride (2) in terms of linear free energy relationships (LFER) are helpful in mechanistic considerations, as is also treatment in terms of the extended Grunwald-Winstein equation. It is proposed that the solvolyses of 1 in binary aqueous solvent mixtures proceed through an SN1 and/or ionization (I) pathway rather than through an associative $S_N2$ and/or addition-elimination (A-E) pathway.

A Chemical Reactor Modeling for Prediction of NO Formation of Methane-Air Lean Premixed Combustion in Jet Stirred Reactor (제트 혼합 반응기 내 희박 예혼합 메탄-공기 연소의 NO 생성 예측을 위한 화학 반응기 모델링)

  • Lee, Bo-Rahm;Park, Jung-Kyu;Lee, Do-Yong;Lee, Min-Chul;Park, Won-Shik
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.34 no.4
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    • pp.365-373
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    • 2010
  • A chemical reactor model (CRM) was developed for a jet stirred reactor (JSR) to predict the emission of exhaust such as NOx. In this study, a two-PSR model was chosen as the chemical reactor model for the JSR. The predictions of NO formation in lean premixed methane-air combustion in the JSR were carried out by using CHEMKIN and GRI 3.0 methane-air combustion mechanism which include the four NO formation mechanisms. The calculated results were compared with Rutar's experimental data for the validation of the model. The effects of important parameters on NO formation and the contributions of the four NO pathways were investigated. In the flame region, the major pathway is the prompt mechanism, and in the post flame region, the major pathway is the Zelodovich mechanism. Under the lean premixed condition, the N2O mechanism is the important pathway in both flame and postflame regions.

Rate and Product Studies of 1-Adamantylmethyl Haloformates Under Solvolytic Conditions

  • Park, Kyoung-Ho;Lee, Yelin;Lee, Yong-Woo;Kyong, Jin Burm;Kevill, Dennis N.
    • Bulletin of the Korean Chemical Society
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    • v.33 no.11
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    • pp.3657-3664
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    • 2012
  • Reactions of 1-adamantylmethyl chloroformate ($1-AdCH_2OCOCl$, 1) and 1-adamantylmethyl fluoroformate ($1-AdCH_2OCOF$, 2) in hydroxylic solvents have been studied. Application of the extended Grunwald-Winstein (G-W) equation to solvolyses of 1 in a variety of pure and binary solvents indicates an addition-elimination pathway in the majority of the solvents except an ionization pathway in the solvents of relatively low nucleophilcity and high ionizing power. The solvolyses of 2 show an addition-elimination pathway in all of the mixed solvents. The leaving group effects ($k_F/k_{Cl}$), the kinetic solvent isotope effects (KSIEs, $k_{MeOH}/k_{MeOD}$), and the enthalpy and entropy of activation for the solvolyses of 1 and 2 were also calculated. The selectivity values (S) for each solvent composition are reported and discussed. These observations are compared with those previously reported for other alkyl haloformate esters.

Activation of MKK6 induces invasive and migrative phenotypes in MCF10A human breast epithelial cells

  • Song, Hyun;Moon, A-Ree
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.170.2-170.2
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    • 2003
  • Ras expression has been suggested as a marker for tumor aggressiveness of breast cancer, including the degrees of invasion and tumor recurrence. We previously showed that p38 MAPK is a key signaling molecule differentially regulated by H-ras and N-ras, leading to H-ras-specific cell invasive and migrative phenotypes in human breast epithelial cells (Cancer Res: 63, 5454-5461, 2003). In this study, we further investigated the role of p38 MARK pathway in the induction of metastatic potential in MCF10A cells as a "gain of function" study. (omitted)

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Sphingosine 1-Phosphate-induced Signal Transduction in Cat Esophagus Smooth Muscle Cells

  • Song, Hyun Ju;Choi, Tai Sik;Chung, Fa Yong;Park, Sun Young;Ryu, Jung Soo;Woo, Jae Gwang;Min, Young Sil;Shin, Chang Yell;Sohn, Uy Dong
    • Molecules and Cells
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    • v.21 no.1
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    • pp.42-51
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    • 2006
  • We investigated the mechanism of contraction induced by S1P in esophageal smooth muscle cells. Western blot analysis demonstrated that $S1P_1$, $S1P_2$, $S1P_3$, and $S1P_5$ receptors existed in the cat esophagus. Only penetration of EDG-5 ($S1P_2$) antibody into permeabilized cells inhibited S1P-induced contraction. Pertussis toxin (PTX) also inhibited contraction, suggesting that it was mediated by $S1P_2$ receptors coupled to a PTXsensitive $G_i$ protein. Specific antibodies to $G_{i2}$, $G_q$ and $G_{\beta}$ inhibited contraction, implying that the S1P-induced contraction depends on PTX-insensitive $G_q$ and $G_{\beta}$ dimers as well as the PTX-sensitive $G_{i2}$. Contraction was not affected by the phospholipase $A_2$ inhibitor DEDA, or the PLD inhibitor ${\rho}$-chloromercuribenzoate, but it was abolished by the PLC inhibitor U73122. Incubation of permeabilized cells with $PLC{\beta}3$ antibody also inhibited contraction. Contraction involved the activation of a PKC pathway since it was affected by GF109203X and chelerythrine. Since $PKC{\varepsilon}$ antibody inhibited contraction, $PKC{\varepsilon}$ may be required. Preincubation of the muscle cells with the MEK inhibitor PD98059 blocked S1P-induced contraction, but the p38 MAP kinase inhibitor SB202190 did not. In addition, co-treatment of cells with GF 109203X and PD98059 did not have a synergistic effect, suggesting that these two kinases are involved in the same signaling pathway. Our data suggest that S1P-induced contraction in esophageal smooth muscle cells is mediated by $S1P_2$ receptors coupled to PTX-sensitive $G_{i2}$ proteins, and PTX-insensitive $G_q$ and $G_{\beta}$ proteins, and that the resulting activation of the $PLC{\beta}3$ and $PKC{\varepsilon}$ pathway leads to activation of a p44/p42 MAPK pathway.

Sec-O-glucosylhamaudol mitigates inflammatory processes and autophagy via p38/JNK MAPK signaling in a rat neuropathic pain model

  • Oh, Seon Hee;Kim, Suk Whee;Kim, Dong Joon;Kim, Sang Hun;Lim, Kyung Joon;Lee, Kichang;Jung, Ki Tae
    • The Korean Journal of Pain
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    • v.34 no.4
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    • pp.405-416
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    • 2021
  • Background: This study investigated the effect of intrathecal Sec-O-glucosylhamaudol (SOG) on the p38/c-Jun N-terminal kinase (JNK) signaling pathways, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)-related inflammatory responses, and autophagy in a spinal nerve ligation (SNL)-induced neuropathic pain model. Methods: The continuous administration of intrathecal SOG via an osmotic pump was performed on male Sprague-Dawley rats (n = 50) with SNL-induced neuropathic pain. Rats were randomized into four groups after the 7th day following SNL and treated for 2 weeks as follows (each n = 10): Group S, sham-operated; Group D, 70% dimethylsulfoxide; Group SOG96, SOG at 96 ㎍/day; and Group SOG192, SOG at 192 ㎍/day. The paw withdrawal threshold (PWT) test was performed to assess neuropathic pain. Western blotting of the spinal cord (L5) was performed to measure changes in the expression of signaling pathway components, cytokines, and autophagy. Additional studies with naloxone challenge (n = 10) and cells were carried out to evaluate the potential mechanisms underlying the effects of SOG. Results: Continuous intrathecal SOG administration increased the PWT with p38/JNK mitogen-activated protein kinase (MAPK) pathway and NF-κB signaling pathway inhibition, which induced a reduction in proinflammatory cytokines with the concomitant downregulation of autophagy. Conclusions: SOG alleviates mechanical allodynia, and its mechanism is thought to be related to the regulation of p38/JNK MAPK and NF-κB signaling pathways, associated with autophagy during neuroinflammatory processes after SNL.

Effect of $N^G$-nitro-L-arginine methyl ester and Methylene Blue on the Endotoxin-induced Vascular Hyporesponsiveness (세균 내독소 유발 혈관 저반응성에 대한 $N^G$-nitro-L-arginine methyl ester와 Methylene blue의 영향)

  • Choi, Hyoung-Chul;Ha, Jeoung-Hee;Lee, Kwang-Youn;Kim, Won-Joon;Sohn, Uy-Dong
    • Journal of Yeungnam Medical Science
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    • v.14 no.2
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    • pp.337-349
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    • 1997
  • This study was undertaken to examine the intensity of involvement of inducible nitric oxide synthase (iNOS) and cyclic GMP signal transduction pathway as one of the mechanisms of vaso-relaxative action of bacterial lipopolysaccharide (LPS) on the canine femoral artery strips. Canine femoral arteries were isolated and spiral strips of 10 mm long and 2 mm wide were made in the Tyrode solution of $0-4^{\circ}C$. The strips were prepared for isometric myography in Biancani's isolated muscle chamber containing 1 ml of Tyrode solution, which was maintained with pH 7.4 by aeration with 95% $O_2$/5% $CO_2$ at $37^{\circ}C$ and nitric oxide (NO) production was measured simulltaneously with isolated nitric oxide meter. LPS induced NO production, suppressed the phenylephrine (PE) induced contraction and enhanced the acetylcholine (ACh) induced relaxation. $N^G$-nitro-L-arginine methyl ester (L-NAME), an NOS inhibitor, methylene blue, a guanylyl cyclase inhibitor, potentiated PE induced contraction and suppressed ACh induced relaxation on the LPS treated strips. The inhibitory potency of methylene blue for LPS induced vascular hyporesponsiveness was stronger than that of L-NAME. These results suggest that in canine femoral artery, both iNOS and cyclic GMP signal trnasduction pathway are related with LPS induced vascular hyporeponsiveness, but in minor with iNOS and in major with cyclic GMP signal trnasduction pathway.

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Sanguinarine Induces Apoptosis in Human Hepatocellular Carcinoma HepG2 Cells through the Generation of ROS and Modulation of Akt/ERK Signaling Pathways (HepG2 인체 간암세포의 ROS 생성 및 ERK/Akt 신호전달 경로 조절을 통한 sanguinarine의 apoptosis 유도)

  • Hwang, Ju Yeong;Cho, Yung Hyun
    • Journal of Life Science
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    • v.25 no.9
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    • pp.984-992
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    • 2015
  • Sanguinarine is a benzophenanthridine alkaloid originally isolated from the roots of Sanguinaria canadensis. It has multiple biological activities (e.g., antioxidant and antiproliferative) and immune-enhancing potential. In this study, we explored the proapoptotic properties and modes of action of sanguinarine in human hepatocellular carcinoma HepG2 cells. Our results revealed that sanguinarine inhibited HepG2 cell growth and induced apoptosis in a dose-dependent manner. The induction of apoptosis by sanguinarine was associated with the up-regulation of Fas and Bax, the release of cytochrome c from the mitochondria to the cytosol, and the loss of the mitochondrial membrane potential. In addition, sanguinarine activated caspase-9 and -8, initiator caspases of the intrinsic and death extrinsic pathways, respectively, and caspase-3, accompanied by proteolytic degradation of poly (ADP-ribose) polymerase. Sanguinarine also triggered the generation of reactive oxygen species (ROS). The elimination of ROS by N-acetylcysteine reversed sanguinarine-induced apoptosis. Furthermore, sanguinarine induced the dephosphorylation of Akt and the phosphorylation of mitogen-activated protein kinases, including extracellular signal-regulated kinase (ERK), c-jun N-terminal kinase (JNK), and p38. The growth inhibition was enhanced by the combined treatment of sanguinarine with a phosphatidylinositol 3'-kinase (PI3K) inhibitor and an ERK inhibitor but not JNK and p38 inhibitors. Overall, our data indicate that the proapoptotic effects of sanguinarine in HepG2 cells depend on ROS production and the activation of both intrinsic and extrinsic signaling pathways, which is mediated by blocking PI3K/Akt and activating the ERK pathway. Thus, our data suggest that sanguinarine may be a natural compound with potential for use as an antitumor agent in liver cancer.