• BMB Reports
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• 제50권7호
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• pp.384-389
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• 2017

The Nogo-B receptor (NgBR) is necessary for not only Nogo-B-mediated angiogenesis but also vascular endothelial growth factor (VEGF) -induced angiogenesis. However, the molecular mechanisms underlying the regulatory role of the VEGF-NgBR axis in angiogenesis are not fully understood. Here, we report that miR-26a serves as a critical regulator of VEGF-mediated angiogenesis through directly targeting NgBR in endothelial cells (ECs). Stimulation of ECs by VEGF increased the expression of NgBR and decreased the expression of miR-26a. In addition, miR-26a decreased the VEGF-induced migration and proliferation of ECs. Moreover, miR-26a overexpression in ECs decreased the VEGF-induced phosphorylation of the endothelial nitric oxide synthase (eNOS) and the production of nitric oxide, which is important for angiogenesis. Overall, these data suggest that miR-26a plays a key role in VEGF-mediated angiogenesis through the modulation of eNOS activity, which is mediated by its ability to regulate NgBR expression by directly targeting the NgBR 3'-UTR.

• 동의생리병리학회지
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• 제21권3호
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• pp.721-727
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• 2007

Scorpion (SCP) has been clinically used for the treatment of endogenous wind to relieve convulsion, clearing away toxins, resolving hard masses and removing obstruction in the collaterals to relieve pain. Recent studies showed that scorpion toxins that affect the activating mechanism of sodium channels and indian black scorpion venom induced anti-proliferative and apoptogenic activity against human leukemic cell lines U937 and K562. There is lack of studies regarding the effects of SCP on the immunological activities. The present study was conducted to evaluate the effect of SCP on the regulatory effects of cytokines and nitric oxide (NO) for the immunological activities in Raw 264.7 cells. After the treatment of SCP MeOH extract dissolved in media for 1 h prior to the addition of lipopolysaccharide (LPS: 1 ${\mu}$g/ml), cell viability was measured by MTT assay, NO production was monitored by measuring the nitrite content in culture medium. Inducible nitric oxide synthase (iNOS) was determined by immunoblot analysis, and levels of cytokine were analyzed by sandwich immunoassays. As results, SCP inhibited the production of nitrite and nitrate (0.3 and 1.0 mg/ml), iNOS and p-$I_KB_{\alpha}$ protein, tumor necrosis factor-${\alpha}$ (0.3 and 1.0 mg/ml), interleukin-1${\beta}$ (0.3 and 1.0 mg/ml) and interleukin-6 (1.0mg/ml) in Raw 264.7 cells activated with LPS. These findings suggest that SCP can produce anti-inflammatory effect, which may play a role in adjunctive therapy in Gram-negative bacterial infections.

• 한국균학회지
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• 제47권3호
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• pp.219-232
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• 2019

Chemicals related to hydrogen peroxide ($H_2O_2$) and nitric oxide (NO) generations were exogenously applied to Fusarium oxysporum f. sp. fragariae (Fof) causing Fusarium wilt disease in strawberry plants, and regulations of in vitro conidial germination and mycelial growth of the fungus by the chemical treatments were evaluated. $H_2O_2$ drastically reduced the conidial germination of Fof in a dose-dependent manner, and treatment with 3-amino-1,2,4-triazole (3-AT) catalase inhibitor also led to dose-dependent inhibition of conidial germination but relatively moderately. Gradual decreases in mycelial growth of Fof were found by high concentrations of $H_2O_2$, whilst exogenous 3-AT slightly increased the mycelial growth. Increasing sodium nitroprusside (SNP) NO donor, $N^G$-nitro-l-arginine methyl ester (L-NAME) NO synthase (NOS)-inhibitor and tungstate nitrate reductase (NR) inhibitor led to dose-dependent reductions in conidial germination of Fof in quite different levels. SNP conversely increased the mycelial growth but increasing L-NAME moderately decreased the mycelial growth. Tungstate strongly enhanced mycelial growth. Differentially regulated in vitro mycelial growths of Fof were demonstrated by SNP, L-NAME and tungstate with or without $H_2O_2$ supplement. Superoxide anion production was also regulated during the mycelial growth of Fof by nitric oxide. These results show that $H_2O_2$ and NO-associated enzymes can be suggested as fungal growth regulators of Fof as well as eco-friendly disease-managing agents in strawberry production fields.

• Journal of Microbiology and Biotechnology
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• 제17권12호
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• pp.2042-2045
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• 2007

The effect of chitosan oligosaccharide (COS, 1 kDa${\gamma}$, 10 ng/ml IL-$1{\alpha}$, and 25 ng/ml TNF-${\alpha}$) in HT-29 cells. Inducible nitric oxide synthase (iNOS) expression induced by these cytokines was inhibited by COS. COS pretreatment inhibited the invasiveness of cytokines-treated HT-29 cells through Matrigel-coated membrane in a dose-dependent manner. COS also inhibited cytokines-induced matrix metalloproteinase (MMP)-2 activity. This study shows that proinflammatory cytokines induce NO production, iNOS expression, and invasiveness of human colorectal adenocarcinoma HT-29 cells. COS pretreatment inhibited cytokines-mediated NO production, iNOS expression, and invasiveness of HT-29 cells. These results provide sufficient information for the further development of COS as an antitumor metastatic agent for the treatment of colon cancer.

• The Korean Journal of Physiology and Pharmacology
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• 제11권4호
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• pp.149-154
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• 2007

Kainic acid (KA) causes neurodegeneration, but no consensus has been reached concerning its mechanism. Nitric oxide may be a regulator of the mechanism. We identified differentially expressed genes in the hippocampus of mice treated with kainic acid, together with or without L-NAME, a nonselective nitric oxide synthase inhibitor, using a new differential display PCR method based on annealing control primers. Eight genes were identified, including clathrin light polypeptide, TATA element modulatory factor 1, neurexin III, ND4, ATPase, $H^+$ transporting, V1 subunit E isoform 1, and N-myc downstream regulated gene 2. Although the functions of these genes and their products remain to be determined, their identification provides insight into the molecular mechanism(s) involved in KA-induced neuronal cell death in the hippocampal CA3 area.

• Natural Product Sciences
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• 제14권3호
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• pp.206-213
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• 2008

This study was designed to investigate the anti-inflammatory effects of mangiferin isolated from the rhizome of Anemarrhena asphodeloides, a natural polyphenol, on lipopolysaccharide (LPS)-treated RAW 264.7 macrophages. Mangiferin dose-dependently inhibited LPS-induced nitric oxide (NO) and prostaglandin $E_2\;(PGE_2)$ productions in RAW 264.7 macrophages and peritoneal macrophages isolated from C57BL/6 mice. Consistent with these data, mangiferin suppressed the LPS-induced expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) at the protein and mRNA levels in a concentration-dependent manner, as determined by Western blotting and RT-PCR, respectively. In addition, the release of tumor necrosis $factor-{\alpha}$($TNF-{\alpha}$) and interleukin-6 (IL-6), and the mRNA expression levels of these cytokines were reduced by mangiferin in a dose-dependent manner. Moreover, mangiferin effectively inhibited the transcriptional activation of nuclear factor-kappa B $(NF-{\kappa}B)$. These results suggest that the anti-inflammatory properties of mangiferin are caused by iNOS, COX-2, $TNF-{\alpha}$, and IL-6 down-regulation due to $(NF-{\kappa}B)$ inhibition in RAW 264.7 macrophages.

• The Korean Journal of Physiology and Pharmacology
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• 제1권3호
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• pp.297-302
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• 1997

Higenamine was widely used as traditional remedy for the treatment of rhumatoid arthritis. Nitric oxide(NO) may be a critical mediator in this inflammatory disease. Synovial tissue from humans with inflammatory arthritis expresses NOS2(iNOS) mRNA and protein, and generates NO in vitro. We therefore, investigated the effect of higenamine on the induction of nitric oxide synthase(NOS) promoted by lipopolysaccharide(LPS). Prophylactic application of higenamine selectively prevented LPS-primed initiation of L-arginine-induced relaxation and restored rhenylephrine(PE)-induced contraction in rat aorta. LPS-stimulated nitrite production in the incubation medium was reduced by higenamine. Furthermore, RT-PCR and Northern analysis indicated that higenamine reduced iNOS expression primed by LPS in rat aorta. These results suggest that higenamine prevents LPS-promoted induction of NOS in vascular smooth muscle.

• Archives of Pharmacal Research
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• 제28권3호
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• pp.297-304
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• 2005

Naturally occurring flavonoids are known to modulate various inflammatory and immune processes. Based on structural property, in this study, molecular mechanism of flavonoids in modulating nitric oxide (NO) production and its signaling pathway were investigated using lipopolysaccharide (LPS)-activated RAW264.7 cells. Although flavonol-typed flavonoids (kaempferol and quercetin) more potently scavenged reactivity of nitric oxide ($\cdot$NO) as well as peroxynitrite (ONOO$\kappa$) than isoflavones (genistein and genistin), kaempferol, quercetin and genistein showed a little difference in inhibition of both inducible NO synthase expression and NO production, with IC$_{50}$ values of 13.9, 20.1 and 26.8 $\mu$M. However, there was a striking pattern related to structural feature in modulation of LPS-mediated signaling pathways. Thus, flavonols only inhibited transcription factor AP-1 activation, whereas isoflavones suppressed the DNA binding activation of NF-$\kappa$B and C/EBP$\beta$. Therefore, these data suggest that structural feature may be linked to decide drugs target molecule in LPS-mediated signaling pathways, rather than its potency.

• Journal of Ginseng Research
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• 제32권2호
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• pp.89-98
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• 2008

There are increasing evidences in the literatures on the potential role of ginsenosides in treating cardiovascular diseases. In this article, current information about ginsenosides-mediated vascular relaxation are reviewed. From the published studies using isolated organs, cell culture systems and animal models, ginsenosides are shown to relax blood vessels and improve blood flow through diverse mechanisms, including nitric oxide release by activating eNOS phosphorylation via PI3K/Akt and/or ERK1/2 pathways in endothelial cells, induction of inducible nitric oxide synthase through activation of NF-${\kappa}$B, reducing the intracelluar Ca$^{2+}$ levels by activating Ca$^{2+}$-activated K$^{+}$ channels in vascular smooth muscle cells and reducing platelet aggregation by decreasing thromboxane A$_2$ formation and intracelluar Ca$^{2+}$in platelets. In addition, the relevant clinical trials regarding the effects of ginsenosides on the cardiovascular disease are summarized, particulary focusing on managing hypertension and improving thrombotic disorders. Finally, antagonistic effects of ginsenosides on the prostaglandin H$_2$ receptor and scavenging effects on the generation of oxygen-derived free radicals in spontaneously hypertensive rats (SHR) are discussed.

• Biomolecules & Therapeutics
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• 제22권5호
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• pp.390-399
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• 2014

Chalcones (1,3-diaryl-2-propen-1-ones), a flavonoid subfamily, are widely known for their anti-inflammatory properties. Propenone moiety in chalcones is known to play an important role in generating biological responses by chalcones. In the present study, we synthesized chalcone derivatives structurally modified in propenone moiety and examined inhibitory effect on nitric oxide (NO) production and its potential mechanisms. Among the chalcone derivatives used for this study, TI-I-174 (3-(2-Hydroxyphenyl)-1-(thiophen-3-yl)prop-2-en-1-one) most potently inhibited lipopolysaccharide (LPS)-stimulated nitrite production in RAW 264.7 macrophages. TI-I-174 treatment also markedly inhibited inducible nitric oxide synthase (iNOS) expression. However, TI-I-174 did not significantly affect production of IL-6, cyclooxygenase-2 (COX-2) and tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), implying that TI-I-174 inhibits production of inflammatory mediators in a selective manner. Treatment of macrophages with TI-I-174 significantly inhibited transcriptional activity of activator protein-1 (AP-1) as determined by luciferase reporter gene assay, whereas nuclear factor-${\kappa}B$ (NF-${\kappa}B$) activity was not affected by TI-I-1744. In addition, TI-I-174 significantly inhibited activation of c-Jun-N-Terminal kinase (JNK) without affecting ERK1/2 and p38MAPK, indicating that down-regulation of iNOS gene expression by TI-I-174 is mainly attributed by blockade of JNK/AP-1 activation. We also demonstrated that TI-I-174 treatment led to an increase in heme oxygenase-1 (HO-1) expression both at mRNA and protein level. Transfection of siRNA targeting HO-1 reversed TI-I-174-mediated inhibition of nitrite production. Taken together, these results indicate that TI-I-174 suppresses NO production in LPS-stimulated RAW 264.7 macrophages via induction of HO-1 and blockade of AP-1 activation.