• Clinical and Experimental Reproductive Medicine
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• 제28권2호
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• pp.111-120
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• 2001

Objective: To verify the expression of leptin receptor (OB-R) in oocytes and preimplantation embryos, the involvement of mitogen activated protein kinase (MAPK or Erk1/2) in the leptin signaling, and effect of leptin on the oocyte maturation in mice. Method: RT-PCR analysis of OB-R was conducted in germinal vesicle (GV)-intact and MII stage oocytes, and 1, 2, 8-cell embryos and blastocysts. Germinal vesicle breakdown (GVB), polar body extrusion, monitored in the presence or absence of leptin ($1{\mu}M$). Following the leptin treatment, temporal changes in MAPK activity were verified by immunoprecipitation and in vitro kinase assay in MII oocytes. Results: The expression of OB-R mRNA was found in GV and MII oocyte but not in the embryos. MAPK activity of the MII oocytes was significantly increased by brief incubation in the HTF supplemented with leptin ($1{\mu}M$). Priming of PD098059, a MEK inhibitor to leptin treatment attenuated the activation of MAPK by leptin in MII oocytes. Following 24 hrs of culture of the GV oocytes, leptin significant increased the GVB and 1 st polar body extrusion. Conclusion: This result suggested that functional interaction between leptin and OB-R resulted in potentiation of MAPK (Erk1/2) activity in MII oocytes through MEK activation and that leptin might be a local regulator of meiotic maturation of the mouse oocytes.

• 생명과학회지
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• 제16권7호
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• pp.1229-1234
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• 2006

배지에 tetracycline이 없으면 사멸하는 평활근세포 (FADD-SMC)를 이용하여 metalloproteinase (MMP)와 사멸세포의 상관관계를 조사하였다. FADD-SMC를 tetracycline이 없는 배지에서 배양하는 경우 핵이 조각으로 잘라졌고 인산화한 p38과 ERK가 증가하고 MMP-9의 발현과 활성이 증가한 반면, cyclin D와 cyclin D의 발현은 감소하였다. 그리고 죽는 FADD-SMC에서 MMP-9의 발현은 immunofluorescen로 재확인하였다. MMP-9의 증가는 MAPK 억제제인 PD098059와 p38 MAPK 억제제인 SB203S80에 의하여 감소하였다. 그리고 MMP 억제제인 BB94는 FADD-SMC의 사멸을 감소시켰다.

• 생약학회지
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• 제44권3호
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• pp.269-274
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• 2013

In this study, we investigated the anticancer effect of rice bran extract in HL-60 human promyelocytic leukemia cells. The extract of rice bran inhibited the proliferation of HL-60 cells. When treated with the rice bran extract, we could observe the apoptotic characteristics such as apoptotic bodies and the increase of sub-G1 hypodiploid cell population, increase of Bax level, decrease of Bcl-2 expression, cleavage of procaspase-3, cleavage of procaspase-9 and cleavage of poly(ADP-ribose) polymerase(PARP) in HL-60 cells. Furthermore, the apoptosis induction of HL-60 cells treated with the rice bran extract was also accompanied by the inactivation of mitogen-activated protein kinases (MAPK) such as ERK1/2 MAPK and p38 MAPK. In addition, the rice bran extract induced the down-regulation of c-myc. These data suggested that the rice bran extract could induce the apoptosis via the inactivation of ERK1/2 MAPK and p38 MAPK, and the down-regulation of c-myc in HL-60 acute pomyelocytic leukemia cells. The results support that the rice bran extract might have potential for the treatment of acute promyelocytic leukemia.

• 대한본초학회지
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• 제37권6호
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• pp.19-28
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• 2022

Objectives : To develop natural ingredients that help prevent or treat anti-inflammatory-related diseases and use themas basic data, we investigated anti-inflammatory activity of Cynanchi Atrati Radix Et Rhizoma water extracts(CWE) in lipopolysaccharide(LPS)-induced murine macrophage cell line, RAW 264.7 cells. Methods : The cell viabilities were evaluated with RAW 264.7 cells. The production of nitric oxide(NO), prostaglandin E2(PGE2), pro-inflammatory cytokines such tumor necrotic factor(TNF)-α and interleukin(IL)-6 were assessed in LPS-induced RAW 264.7 cell treated with CWE. Furthermore, the protein expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2(COX-2), and mitogen-activated protein kinase(MAPK) were assessed by western blotting. Results : In RAW 264.7 cell, the cell viability by CWE treatment was more than 98.4% at a concentration of 100-400 ㎍/mL. At a concentration of 800 ug/ml of CWE, the cell viability was as low as 86%. At doses of 100, 200 and 400 ㎍/mL, CWE inhibited the production of NO, PGE2, TNF-𝛼 and IL-6 in a dose-dependent manner and also decreased the expression of iNOS and COX-2 from LPS-induced RAW 264.7 cells. In addition, CWE significantly inhibited the MAPK pathway including decreased the phosphorylation of the p38, c-Jun N-terminal kinase(JNK) and extracellular signal-regulated kinase(ERK1/2). Conclusions : Our study provides evidence that CWE inhibits the production of main pro-inflammatory molecules in LPS-induced RAW 264.7 cells via expression of p38, JNK, and ERK1/2 MAPK signaling pathways. Therefore, CWE is expected to be widely used as a natural ingredient for anti-inflammatory functional foods or pharmaceuticals in the future.

• Biomolecules & Therapeutics
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• 제22권6호
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• pp.503-509
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• 2014

Paraquat has been suggested to induce apoptosis by generation of reactive oxygen species (ROS). However, little is known about the mechanism of paraquat-induced apoptosis. Here, we demonstrate that extracellular signal-regulated protein kinase (ERK) is required for paraquat-induced apoptosis in NIH3T3 cells. Paraquat treatment resulted in activation of ERK, and U0126, inhibitors of the MEK/ERK signaling pathway, prevented apoptosis. Moreover, paraquat-induced apoptosis was associated with cytochrome C release, which could be prevented by treatment with the MEK inhibitors. Taken together, our findings suggest that ERK activation plays an active role in mediating paraquat-induced apoptosis of NIH3T3 cells.

• Parasites, Hosts and Diseases
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• 제55권6호
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• pp.613-622
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• 2017

IL-12 and IL-23 are closely related in structure, and have been shown to play crucial roles in regulation of immune responses. However, little is known about the regulation of these cytokines in T cells. Here, we investigated the roles of PI3K and MAPK pathways in IL-12 and IL-23 production in human Jurkat T cells in response to Toxoplasma gondii and LPS. IL-12 and IL-23 production was significantly increased in T cells after stimulation with T. gondii or LPS. T. gondii and LPS increased the phosphorylation of AKT, ERK1/2, p38 MAPK, and JNK1/2 in T cells from 10 min post-stimulation, and peaked at 30-60 min. Inhibition of the PI3K pathway reduced IL-12 and IL-23 production in T. gondii-infected cells, but increased in LPS-stimulated cells. IL-12 and IL-23 production was significantly reduced by ERK1/2 and p38 MAPK inhibitors in T. gondii- and LPS-stimulated cells, but not in cells treated with a JNK1/2 inhibitor. Collectively, IL-12 and IL-23 production was positively regulated by PI3K and JNK1/2 in T. gondii-infected Jurkat cells, but negatively regulated in LPS-stimulated cells. And ERK1/2 and p38 MAPK positively regulated IL-12 and IL-23 production in Jurkat T cells. These data indicate that T. gondii and LPS induced IL-12 and IL-23 production in Jurkat T cells through the regulation of the PI3K and MAPK pathways; however, the mechanism underlying the stimulation of IL-12 and IL-23 production by T. gondii in Jurkat T cells is different from that of LPS.

• 한국임상수의학회지
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• 제30권5호
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• pp.339-345
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• 2013

MAPKs는 다양한 세포자극에 반응하는 중요한 세포신호전달경로이며, 특히 세포의 생존과 사멸과정에 관여한다고 알려져 있다. 그러나 위궤양의 진행에 있어 MAPKs의 세포특이적 활성에 관한 연구결과들에 대해서는 잘 알려져 있지 않다. 본 연구에서는 이부프로펜에 의해 유도된 위궤양의 진행에 있어 활성화된 MAPKs가 다양한 세포들에 어떻게 분포하는지를 실험하였다. 위궤양 유발은 200 mg/kg 이부프로펜을 하루에 8시간간격으로 3번 투여하였다. 동물부검은 이부프로펜을 투여한 후 24, 48, 72시간에 실시하였고, 위조직은 면역조직화학 및 웨스턴블랏에 사용되었다. 활성화된 p-ERK는 정상 랫드 위점막상피의 위상피증식층에서만 주로 발현되었으나, 이부프로펜을 투여한 후 24시간째에는 위기저부의 벽세포들에서 강하게 발현되었다. 이부프로펜을 투여 후 48시간 경과한 군에 있어서는 위궤양에 인접한 위점막상피 또는 위궤양 기저부의 결합조직에 나타난 신생혈관, 염증세포 및 육아조직에서 p-ERK가 강하게 발현되었다. 반면에 p-JNK는 초기 위점막손상을 나타내는 위표면점막상피와 샘위의 점막상피세포의 핵에서 주로 발현되었다. 점차적으로 p-JNK는 위궤양 기저부의 결합조직내에 침윤된 염증세포, 섬유모세포에서 특히 강하게 염색되었다. P-p38 양성세포는 위점막의 결합조직내에서 분산되어 관찰되었으며, 특히 위궤양 기저부의 결합조직내로 침윤된 대식 세포에 강한 염색성을 나타내었다. 이상의 연구결과는 각각의 MAPK들이 위궤양진행에 있어 특정세포들의 활성화에 관여하는 것으로 보여진다.

• 대한본초학회지
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• 제22권2호
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• pp.147-153
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• 2007

Objectives : Sophora flavescens (SF) is widely used in traditional herbal medicine in Korea and is well recognized for its anti-inflammatory effect. However, its effect on Tumornecrosis factor alpha (Tnf) production in BV2 microglial cell is not yet known. Methods : We investigated the effect of SF on the production and expression of Tnf, a well known inflammatory mediator, in lipopolysaccaride (LPS)-activated BV2 microglial cells. Results : The LPS-induced Tnf production was markedly reduced by treatment with SF (50 ${\mu}g/ml$). In reverse transcription polymerase chain reaction (RT-PCR) analysis, SF suppressed the LPS activated expression of Tnf mRNA. In addition, Western blot analysis confirmed that SF suppressed the expression of Tnf. Sophora flavescens also inhibited the LPS-induced phosphylation of extracellular signal-regulated kinases (ERK), which mediate the Tnfproduction signaling pathway whereas LPS-induced phosphylation of p38 mitogen activated protein kinase (p38 MAPK), and c-Jun NH2-terminal kinases (JNK) was not inhibited by SF, which implies that SF suppresses LPS-induced Tnf production via the ERK mediated pathway. Conclusion : Taken together, these findings indicated that SF inhibits LPS-induce Tnf production, and that this inhibitory effect is mediated via the ERK pathway.

• Journal of Korean Neurosurgical Society
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• 제46권4호
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• pp.389-396
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• 2009

Objective : Triptolide (TP) has been reported to suppress the expression of mitogen-activated protein kinase (MAPK) phosphatase-1 (MKP-1), of which main function is to inactivate the extracellular signal-regulated kinase-1/2 (ERK-1/2), the p38 MAPK and the c-Jun N-terminal kinase-1/2 (JNK-1/2), and to exert antiproliferative and pro-apoptotic activities. However, the mechanisms underlying antiproliferative and pro-apoptotic activities of TP are not fully understood. The purpose of this study was to examine whether the down-regulation of MKP-1 expression by TP would account for antiproliferative activity of TP in immortalized HT22 hippocampal cells. Methods : MKP-1 expression and MAPK phosphorylation were analyzed by Western blot. Cell proliferation was assessed by $^3H$-thymidine incorporation. Small interfering RNA (siRNA) against MKP-1, vanadate (a phosphatase inhibitor), U0126 (a specific inhibitor for ERK-1/2), SB203580 (a specific inhibitor for p38 MAPK), and SP600125 (a specific inhibitor for JNK-1/2) were employed to evaluate a possible mechanism of antiproliferative action of TP. Results : At its non-cytotoxic dose, TP suppressed MKP-1 expression, reduced cell growth, and induced persistent ERK-1/2 activation. Similar growth inhibition and ERK-1/2 activation were observed when MKP-1 expression was blocked by MKP-1 siRNA and its activity was inhibited by vanadate. The antiproliferative effects of TP, MKP-1 siRNA, and vanadate were significantly abolished by U0126, but not by SB203580 or SP600125. Conclusion : Our findings suggest that TP inhibits the growth of immortalized HT22 hippocampal cells via persistent ERK-1/2 activation by suppressing MKP-1 expression. Additionally, this study provides evidence supporting that MKP-1 may play an important role in regulation of neuronal cell growth.

• 한국발생생물학회:학술대회논문집
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• 한국발생생물학회 2001년도 후기 제12차 학술대회 논문집
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• pp.45-47
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• 2001

생쥐 착상전 초기배아에서 insulin과 tumor necrosis factor $\alpha$ (TNF$\alpha$)에 의한 배아의 형태 발생, 세포증식, apoptosis 및 MAPK활성의 변화를 조사하였다. Insulin에 의해 형태발생 및 포배당 세포수가 증가되었으며 TNF $\alpha$ 처리시 유의하게 감소하였다. TNT$\alpha$ 전처리시 insulin에 의한 발생 및 세포수 증가 촉진효과가 상쇄되었으며 TNF$\alpha$는 배아내 caspase-3의 활성을 증가시켰다. Insulin은 단시간내에 포배에서 mitogen activated protein kinase (MAPK or Erk1/2)의 활성을 증가시켰다. TNF$\alpha$는 포배내 MAPK의 활성을 감소시켰다. Insulin 처리 전 TNF $\alpha$를 전처리한 경우 insulin에 의한 MAPK 활성의 증가가 상쇄되었다. 배발생을 촉진하는 인슐린 신호전달 과정은 MAPK cascade를 경유하며 TNF $\alpha$를 경유한 신호전달과 Crosstalk이 존재하는 것으로 사료된다.