• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.76.2-76.2
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• 2003

Although sphingosine-1-phosphate (S1P) is a well-known mitogen, our results show that S1P potently inhibits keratinocyte proliferation, and that this leads the inhibition of DNA synthesis. Interestingly, the prolonged activation of extracellular signal-regulated protein kinase (ERK) and the transient inactivation of Akt/protein kinase B (PKB) were also oberved in concert with the inhibition of keratinocyte proliferation by S1P. To further verify the anti-proliferative action of S1P, we examined changes in cell cycle related proteins. (omitted)

• Archives of Pharmacal Research
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• 제26권7호
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• pp.545-553
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• 2003

The expression of cyclooxygenase-2 (COX-2) is a characteristic response to inflammation, which can be inhibited with sodium salicylate. IL-1$\beta$ and TNF-$\alpha$ can induce extracellular signal-regulated kinase (ERK), IKK, IkB degradation and NF-$\kappa$B activation. Salicylate inhibited the IL-1$\beta$ and TNF-$\alpha$-induced COX-2 expressions, regulated the activation of ERK, IKK and IkB degradation, and the subsequent activation of NF-$\kappa$B, in neonatal rat ventricular cardiomyocytes. The inhibition of the ERK pathway, with a selective inhibitor, PD098059, blocked the expressions of IL-1$\beta$ and TNF-$\alpha$-induced COX-2 and $PGE_2$ release. The antioxidant, N-acetyl-cysteine, also reduced the glutathione or catalase- attenuated COX-2 expressions in IL-1$\beta$ and TNF-$\alpha$-treated cells. This antioxidant also inhibited the activation of ERK and NF-$\kappa$B in neonatal rat cardiomyocytes. In addition, IL-1$\beta$ and TNF-$\alpha$-stimulated the release of reactive oxygen species (ROS) in the cardiomyocytes. However, salicylate had no inhibitory effect on the release of ROS in the DCFDA assay. The results showed that salicylate inhibited the activation of ERK and IKK, I$\kappa$B degradation and NF-$\kappa$B activation, independently of the release of ROS, which suggested that salicylate exerts its anti-inflammatory action through the inhibition of ERK, IKK, IkB and NF-$\kappa$B, and the resultant COX-2 expression pathway in neonatal rat ventricular cardiomyocytes.

• The Korean Journal of Physiology and Pharmacology
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• 제7권4호
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• pp.239-246
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• 2003

The expression of cyclooxygenase-2 (COX-2) is a characteristic response to inflammation and can be inhibited with sodium salicylate. $TNF-{\alpha}$ plus $IFN-{\gamma}$ can induce extracellular signal-regulated kinase (ERK), IKK, $I{\kappa}B$ degradation and NF-${\kappa}B$ activation. The inhibition of the ERK pathway with selective inhibitor, PD098059, blocked cytokine-induced COX-2 expression and $PGE_2$ release. Salicylate treatment inhibited COX-2 expression induced by $TNF-{\alpha}$/$IFN-{\gamma}$ and regulated the activation of ERK, IKK and $I{\kappa}B$ degradation and subsequent NF-${\kappa}B$ activation in MC3T3E1 osteoblasts. Furthermore, antioxidants such as catalase, N-acetyl-cysteine or reduced glutathione attenuated COX-2 expression in combined cytokines-treated cells, and also inhibited the activation of ERK, IKK and NF-${\kappa}B$ in MC3T3E1 osteoblasts. In addition, $TNF-{\alpha}$/$IFN-{\gamma}$ stimulated ROS release in the osteoblasts. However, salicylate had no obvious effect on ROS release in DCFDA assay. The results showed that salicylate inhibited the activation of ERK and IKK, $I{\kappa}B$ degradation and NF-${\kappa}B$ activation independent of ROS release and suggested that salicylate exerts its anti-inflammatory action in part through inhibition of ERK, IKK, $I{\kappa}B$, $NF-{\kappa}B$ and resultant COX-2 expression pathway.

• Toxicological Research
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• 제22권3호
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• pp.283-291
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• 2006

The survival and growth of epithelial cells depends on adhesion to the extracellular matrix. An adhesion signal may regulate the initiation of differentiation, since epidermal keratinocytes differentiate as they leave the basement membrane. A metabolically dead cornified cell envelope is the end point of epidermal differentiation so that this process may be viewed as a specialized form of programmed cell death. In order to investigate the precise cellular signaling events loading to terminal differentiation of keratinocytes, we have utilized HaCaT cells to monitor the biological consequences of $Ca^{2+}$ stimulation and numerous downstream signaling pathways, including activation of the extracellular signal-regulated protein kinase(ERK) pathway and activation of phosphatidylinositol 3-kinase(PI3K). The results presented in this study show that $Ca^{2+}$ function as potent agents for the differentiation of HaCaT keratinocytes, and this differentiation depends or the activation of ERK, Protein kinase B(PKB) and p70 ribosomal protein S6 kinase(p70S6K). Finally, the results show that the expression of Activator protein 1(AP-1; c-Jun and c-Fos) increased following $Ca^{2+}$-mediated differentiation of HaCaT cells, suggesting that ERK-mediated AP-1 expression is critical for initiating the terminal differentiation of keratinocytes.

• Journal of Animal Science and Technology
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• 제59권7호
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• pp.16.1-16.6
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• 2017

Background: This study was performed to investigate the impact of exogenous ghrelin on the pancreatic ${\alpha}$-amylase outputs and responses of pancreatic proteins to ghrelin that may relate to pancreatic exocrine. Methods: Sprague-Dawley male rats (9 weeks old, $300{\pm}10g$) were injected with ghrelin via intraperitoneal (i.p.) infusion at dosage of 0, 0.1, 1.0 and $10.0{\mu}g/kg$ body weight (BW), respectively. The plasma ghrelin and cholecystokinin (CCK) level were determined using enzyme immunoassay kit; the mRNA expression of ghrelin receptor ($GHSR-1{\alpha}$) and growth hormone (GH) receptor were assessed by reverse transcription PCR; the expressions of pancreatic ${\alpha}$-amylase activity, extracellular-signal-regulated kinases (ERK), phosphorylated extracellular-signal-regulated kinases (pERK) and c-Jun N-terminal kinase (JNK) were evaluated by western blotting; moreover the responses of pancreatic proteins to ghrelin were analyzed using the two-dimensional gel electrophoresis system. Results: The exogenous ghrelin (1.0 and $10.0{\mu}g/kg\;BW$) elevated the level of plasma ghrelin (p < 0.05), and suppressed the expression of pancreatic ${\alpha}$-amylase at a dose of $10.0{\mu}g/kg\;BW$ (p < 0.05). No difference in the level of plasma CCK was observed, even though rats were exposed to any dose of exogenous ghrelin. In addition, a combination of western blot and proteomic analysis revealed exogenous ghrelin ($10.0{\mu}g/kg\;BW$) induced increasing the JNK and ERK expressions (p < 0.05) and four proteins such as Destrin, Anionic trypsin-1, Trypsinogen, and especially eukaryotic translation initiation factor 3 in rat pancreas. Conclusions: Taken together, exogenous ghrelin by i.p. infusion plays a role in the pancreatic exocrine secretion via mitogen-activated protein kinase signaling pathway.

• Korean Journal of Acupuncture
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• 제28권4호
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• pp.49-58
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• 2011

목적 : 본 연구는 감초의 염증에 대한 효과를 연구하였다. 감초의 에탄올 그리고 물로 추출한 두 가지의 약침액을 이용하여 쥐의 대식세포에서 유래한 RAW264.7 세포에 대한 염증 억제효과를 확인하였다. 방법 : Inducible nitric oxide synthase(iNOS), cyclooxygenase-2(COX-2)를 포함한 염증성 단백질의 발현과 extracellular signal-regulated kinase 1/2(ERK1/2) 그리고 phosphorylated ERK1/2 의 발현을 Western blot 으로 확인하였고, PGE2의 발현은 ELISA 로 확인하였다. 결과 : RAW264.7 세포에 감초의 물 혹은 에탄올 추출 약침액을 투여한 결과 투여된 농도에 따라 LPS로 유도된 NO의 생성이 억제되었으며 iNOS, COX-2, 그리고 인산화 ERK1/2 의 발현도 감소되었다. 결론 : 본 실험 결과, 적작약의 물 그리고 에탄올 추출 약침액에 대하여 항염증성 효과가 있음을 확인하였다.

• The Korean Journal of Physiology and Pharmacology
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• 제24권3호
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• pp.259-266
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• 2020

Cardiovascular diseases are the primary reason of mortality, among which myocardial infarction (MI) is the most dominant and prevalent. This study was considered to examine D-Limonene protective action against isoproterenol (ISO) induced MI. Wister male rats were dispersed into four groups. Normal and D-Limonene control group in which rats administered saline or D-Limonene. ISO control animals were administered saline for 21 days then challenged with ISO (85 mg/kg, subcutaneously) on 20th and 21st day for MI induction. D-Limonene pretreated group in which animals were pretreated with D-Limonene 50 mg/kg orally for 21 days then administered ISO on 20th and 21st day. MI prompted variations were assessed by myocardial infarction area determination, blood pressure (BP) alterations, cardiac injury biomarkers and inflammatory mediators measurements. For more depth investigation, both the apoptotic status was evaluated via measuring mRNA expression of Bcl-2 and Bax as well as mitogen-activated protein kinase-extracellular signal-regulated kinase (MAPK-ERK) signal transduction were investigated via Western blotting. MI group revealed significant infarcted area, blood pressure alterations, myocardial injury enzymes intensification together with inflammatory cytokines amplification. MI was associated with activation of MAPK-ERK signal pathway and apoptotic status within the myocardium. On the other hand, pretreated with D-Limonene demonstrated deterred infracted area, reduced myocardial enzymes, improved BP indices, lessened inflammatory levels. Furthermore, D-Limonene pretreatment caused a decline in MAPK proteins pathway and Bax relative mRNA expression, while intensifying Bcl-2 mRNA expression promoting that D-Limonene may constrain MI induced myocardial apoptosis. D-Limonene mitigated MI injury through MAPK/NF-κB pathway inhibition and anti-apoptotic effect.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2019년도 추계학술대회
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• pp.90-90
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• 2019

Hibiscus syriacus exhibited promising potential as a new source of food and colorants containing various anthocyanins. However, the function of anthocyanins from H. syriacus has not been investigated. In the current study, we evaluated whether anthocyanins from the H. syriacus varieties Pulsae and Paektanshim (PS and PTS) inhibit melanin biogenesis. B16F10 cells and zebrafish larvae were exposed to PS and PTS in the presence or absence of ${\alpha}$-melanocyte-stimulating hormone (${\alpha}$-MSH), and melanin contents accompanied by its regulating genes and proteins were analyzed. PS and PTS moderately downregulated mushroom tyrosinase activity in vitro, but significantly decreased extracellular and intracellular melanin production in B16F10 cells, and inhibited ${\alpha}$-MSH-induced expression of microphthalmia-associated transcription factor (MITF) and tyrosinase. PS and PTS also attenuated pigmentation in ${\alpha}$-MSH-stimulated zebrafish larvae. Furthermore, PS and PTS activated the phosphorylation of extracellular signal-regulated kinase (ERK), whereas PD98059, a specific ERK inhibitor, completely reversed PS- and PTS-mediated anti-melanogenic activity in B16F10 cells and zebrafish larvae, which indicates that PS- and PTS-mediated anti-melanogenic activity is due to ERK activation. Moreover, chromatography data showed that PS and PTS possessed 17 identical anthocyanins as a negative regulator of ERK. These findings suggested that anthocyanins from PS and PTS inhibited melanogenesis in vitro and in vivo by activating the ERK signaling pathway.

• The Korean Journal of Physiology and Pharmacology
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• 제25권2호
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• pp.159-166
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• 2021

Nicotinamide adenine dinucleotide phosphate oxidases (NOXs) are the major enzymatic source of reactive oxygen species (ROS). NOX2 and NOX4 are expressed in the heart but its role in hypoxia-induced atrial natriuretic peptide (ANP) secretion is unclear. This study investigated the effect of NOX on ANP secretion induced by hypoxia in isolated beating rat atria. The results showed that hypoxia significantly upregulated NOX4 but not NOX2 expression, which was completely abolished by endothelin-1 (ET-1) type A and B receptor antagonists BQ123 (0.3 μM) and BQ788 (0.3 μM). ET-1-upregulated NOX4 expression was also blocked by antagonists of secreted phospholipase A2 (sPLA2; varespladib, 5.0 μM) and cytosolic PLA2 (cPLA2; CAY10650, 120.0 nM), and ET-1-induced cPLA2 expression was inhibited by varespladib under normoxia. Moreover, hypoxia-increased ANP secretion was evidently attenuated by the NOX4 antagonist GLX351322 (35.0 μM) and inhibitor of ROS N-Acetyl-D-cysteine (NAC, 15.0 mM), and hypoxia-increased production of ROS was blocked by GLX351322. In addition, hypoxia markedly upregulated Src expression, which was blocked by ET receptors, NOX4, and ROS antagonists. ET-1-increased Src expression was also inhibited by NAC under normoxia. Furthermore, hypoxia-activated extracellular signal-regulated kinase 1/2 (ERK1/2) and protein kinase B (Akt) were completely abolished by Src inhibitor 1 (1.0 μM), and hypoxia-increased GATA4 was inhibited by the ERK1/2 and Akt antagonists PD98059 (10.0 μM) and LY294002 (10.0 μM), respectively. However, hypoxia-induced ANP secretion was substantially inhibited by Src inhibitor. These results indicate that NOX4/Src modulated by ET-1 regulates ANP secretion by activating ERK1/2 and Akt/GATA4 signaling in isolated beating rat hypoxic atria.

• 동의생리병리학회지
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• 제22권2호
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• pp.385-389
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• 2008

Nitric oxide (NO) has been suggested to play an important role in endotoxin-mediated shock and inflammation. In this study, we investigated the effect of Rosa laevigata Michx. (Rosaceae) on the production of NO and the molecular mechanism of its action. Rosa laevigata inhibited NO generation and iNOS expression in LPS-stimulated murine macrophages. Activity of nuclear $factor{-\kappa}B\;(NF{-\kappa}B)$ and the degradation of $I{\kappa}B-{\alpha}$ were suppressed by Rosa laevigata. Furthermore, extracellular signal-stimulated kinase (ERK), which is known to be involved in $NF{-\kappa}B$ activation, is inhibited by Rosa laevigata. These results suggest that Rosa laevigata could exert its anti-inflammatory actions by suppressing the synthesis of NO through inhibition of $NF{-\kappa}B$ activity.