• The Korean Journal of Physiology and Pharmacology
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• 제21권3호
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• pp.345-352
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• 2017

Since previous studies have reported that hydroquinone (HQ) exerted immunosuppressive and anti-inflammatory activity, various HQ derivatives have been synthesized and their biological activities investigated. In this study, we explored the anti-inflammatory activity of JS-III-49, a novel HQ derivative, in macrophage-mediated inflammatory responses. JS-III-49 suppressed the production of the inflammatory mediators nitric oxide (NO) and prostaglandin $E_2$ ($PGE_2$) and down-regulated the mRNA expression of the inflammatory enzymes cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) as well as the expression of the pro-inflammatory cytokines interleukin-6 (IL-6) and IL-$1{\beta}$ without cytotoxicity in LPS-stimulated RAW264.7 cells. JS-III-49 inhibited nuclear translocation of the $NF-{\kappa}B$ transcription factors p65 and p50 by directly targeting Akt, an upstream kinase of the $NF-{\kappa}B$ pathway, in LPS-stimulated RAW264.7 cells. However, JS-III-49 did not directly inhibit the kinase activities of Src and Syk, which are upstream kinases of Akt, in LPS-stimulated RAW264.7 cells. Moreover, JS-III-49 suppressed the nuclear translocation of c-Fos, one of the components of AP-1, by specifically targeting p38, an upstream mitogen-activated protein kinase (MAPK) in the AP-1 pathway in LPS-stimulated RAW264.7 cells. These results suggest that JS-III-49 plays an anti-inflammatory role in LPS-stimulated macrophages by targeting Akt and p38 in the $NF-{\kappa}B$ and AP-1 pathways, respectively.

• 한국환경성돌연변이발암원학회:학술대회논문집
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• 한국환경성돌연변이발암원학회 2002년도 Molecular and Cellular Response to Toxic Substances
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• pp.14-40
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• 2002

15-Deoxy-${\Delta}^{12, 14}$-prostaglandin $J_2$ (15-deoxy-$PGJ_2$), a naturally occurring ligand activates the peroxisome proliferator-activated $receptor-{\gamma}(PPAR-{\gamma}$). Activation of $PPAR-{\gamma}$ has been found to induce cell differentiation such as adipose cell and macrophage. Here it was investigated whether 15-deoxy-$PGJ_2$ has neuronal cell differentiation and possible underlying molecular mechanisms. Dopaminergic differentiating PC 12 cells treated with 15-deoxy-$PGJ_2$ (0.2 to 1.6 ${\mu}M$) alone showed measurable neurite extension and expression of neurofilament, markers of cell differentiation. However much greater extent of neurite extension and expression of neurofilament was observed in the presence of NGF (50 ng/ml). In parallel with its increasing effect on the neurite extension and expression of neurofilament, 15-deoxy-$PGJ_2$ enhanced NGF-induced p38 MAP kinase expression and its phosphorylation in addition to the activation of transcription factor AP-1 in a dose dependent manner. Moreover, pretreatment of SD 203580, a specific inhibitor of p38 MAP kinase inhibited the promoting effect of 15-deoxy-$PGJ_2$(0.8 ${\mu}M$) on NGF-induced neurite extension. This inhibition correlated well with the ability of SB203580 to inhibit the enhancing effect of 15-deoxy-$PGJ_2$ on the expression of p38 MAP kinase and activation of AP-1, The promoting ability of 15-deoxy-$PGJ_2$ did not occur through $PPAR-{\gamma}$, as synthetic PPAR-${\gamma}$ agonist andantagonist did not change the neurite promoting effect of 15-deoxy-PGJ$_2$. In addition, contrast to other cells (embryonic midbrain and SK-N-MC cells), $PPAR-{\gamma}$ was not expressed in PC-12 cells. Other structure related prostaglandins, PGD$_2$ and $PGE_2$ acting via a cell surface G-protein-coupled receptor (GPCR) did not increase basal or NGF-induced neurite extension. Moreover, GPCR (EP and DP receptor) antagonists did not alter the promoting effect of f 5-deoxy-$PGJ_2$ on neurite extension and activation of p38 MAP kinase, suggesting that the promoting effect of 15-deoxy-$PGJ_2$ may not be mediated GPCR. These data demonstrate that activation of p38 MAP kinase in conjunction with AP-1 single pathway may be important in the promoting activity of 15-deoxy-$PGJ_2$ cells.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2002년도 Molecular and Cellular Response to Toxic Substances
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• pp.14-40
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• 2002

15-Deoxy- Δ$\^$12,14/-prostaglandin J$_2$ (15-deoxy-PGJ$_2$), a naturally occurring ligand activates the peroxisome proliferator-activated receptor-${\gamma}$ (PPAR-${\gamma}$). Activation of PPAR-y has been found to induce cell differentiation such as adipose cell and macrophage. Here it was investigated whether 15-deoxy-PGJ$_2$ has neuronal cell differentiation and possible underlying molecular mechanisms. Dopaminergic differentiating PC 12 cells treated with 15-deoxy-PGJ$_2$ (0.2 to 1.6 ${\mu}$M) alone showed measurable neurite extension and expression of neurofilament, markers of cell differentiation. However much greater extent of neurite extension and expression of neurofilament was observed in the presence of NGF (50 ng/$m\ell$). In parallel with its increasing effect on the neurite extension and expression of neurofilament, 15-deoxy-PGJ$_2$ enhanced NGF-induced p38 MAP kinase expression and its phosphorylation in addition to the activation of transcription factor AP-1 in a dose dependent manner. Moreover, pretreatment of SD 203580, a specific inhibitor of p38 MAP kinase inhibited the promoting effect of 15-deoxy-PGJ$_2$ (0.8 ${\mu}$M) on NGF-induced neurite extension. This inhibition correlated well with the ability of SB203580 to inhibit the enhancing effect of 15-deoxy-PGJ$_2$ on the expression of p38 MAP kinase and activation of AP-1. The promoting ability of 15-deoxy-PGJ$_2$ did not occur through PPAR-${\gamma}$, as synthetic PPAR-${\gamma}$ agonist and antagonist did not change the neurite promoting effect of 15-deoxy-PGJ$_2$. In addition, contrast to other cells (embryonic midbrain and SK-N-MC cells), PPAR-${\gamma}$ was not expressed in PC-12 cells. Other structure related prostaglandins, PGD$_2$ and PGE$_2$ acting via a cell surface G-protein-coupled receptor (GPCR) did not increase basal or NGF-induced neurite extension. Moreover, GPCR (EP and DP receptor) antagonists did not alter the promoting effect of 15-deoxy-PGJ$_2$ on neurite extension and activation of p38 MAP kinase, suggesting that the promoting effect of 15-deoxy-PGJ$_2$ may not be mediated GPCR. These data demonstrate that activation of p38 MAP kinase in conjunction with AP-1 signal pathway may be important in the promoting activity of 15-deoxy-PGJ$_2$ on the differentiation of PC12 cells.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2005년도 춘계 국제심포지엄 및 학술대회
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• pp.160-160
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• 2005

• Tuberculosis and Respiratory Diseases
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• 제58권6호
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• pp.590-599
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• 2005

연구배경 : 만성폐쇄성폐질환에서 나타나는 기도점액의 과다분비는 이 질환의 중요한 병리학적 소견이며 호흡곤란 등 환자의 증상을 악화시키는 요인 중의 하나이다. 기도 점액을 구성하는 여러 성분 중 Muc 유전자에 의해 만들어지는 당 단백이 흡연에 의해 생성이 증가하는데 이에 관여하는 세포 내 신호전달 과정에 대하여 확실히 밝혀진 바가 없다. 저자는 Muc 유전자 중 인체의 기도에 가장 많이 분비되는 Muc5ac 점액 생성을 담당하는 Muc5ac 유전자의 발현이 흡연에 의하여 증가하는데 관여하는 세포 내 신호전달 과정을 알아보고자 하였다. 재료 및 방법 : 사람 폐선암 세포주인 A549 세포를 배양하여 Muc5ac 유전자의 promotor를 luciferase reporter plasmid를 사용하여 세포 내에 transfection시키고 5% 담배연기 추출물로 자극하여 배양하였다. 또 세포 내 신호전달에 관여하는 표피성장인자 수용체 kinase의 억제제인 AG1478, mitogen-activated protein kinase kinase(MAPKK) 억제제인 PD98059, p38 mitogen-activated protein kinase 억제제인 SB203580으로 각각 전 처치 후 역시 5% 담배연기 추출물로 자극 배양하였다. 배양된 세포에서 단백질을 추출하여 luciferase 분석을 통하여 Muc5ac promoter 활성도를 측정하고 Western blot을 이용하여 표피성장인자 수용체와 mitogen-activated protein kinase (MAPK)인 extracellular signalrelated kinase (ERK)1/2, p38 MAPK, c-Jun N-terminal kinase (JNK)의 발현을 확인하였다. 또 세포에서 RNA를 추출한 후 Muc5ac primer를 이용하여 역전사효소 중합연쇄반응을 수행하여 Muc5ac mRNA 발현을 관찰하였다. 결 과 : 1. Muc5ac promoter를 삽입한 A549 세포를 5% 담배연기 추출물로 자극하였을 때 의의 있게 luciferase 활성도가 증가하였고(P<0.001) 자극하는 시간이 3시간이었을 때 luciferase 활성도가 최고치를 보였다(P<0.01). 또 담배연기 추출물 자극은 표피성장인자 수용체를 인산화시켰으며 인산화는 AG1478과 PD98059에 의하여 억제되었다. 2. AG1478 혹은 PD98059로 전 처치 후 5% 담배연기 추출물로 자극한 경우 5% 담배연기 추출물 단독으로 자극한 것에 비하여 유의하게 lucifearse 활성도가 억제되었고 (P<0.01) 세 가지 종류의 MAPK 중 ERK1/2와 p38 MAPK의 인산화는 관찰되었으나 JNK의 인산화는 관찰되지 않았다. 역전사효소 중합연쇄반응을 이용하여 관찰한 Muc5ac mRNA 발현은 담배연기 추출물에 의해 증가되었고 PD98059와 AG1478에 의하여 역시 억제되었다. 3. 담배연기 추출물에 의하여 인산화 된 ERK1/2는 PD98059에 의하여 인산화가 감소하였고 p38 MAPK의 인산화는 PD98059와 SB203580에 의하여 감소하였으며 이 두 가지 억제제는 모두 luciferase 활성도를 유의하게 억제시켰다(P<0.0001). 결 론 : 담배연기 추출물은 Muc5ac 유전자의 발현을 증가시켜 기도 내 점액 분비를 증가시키며 이는 표피성장인자 수용체를 매개로 ERK1/2와 p38 MAPK를 경유하여 세포 내 신호전달이 이루어진다고 생각된다. 따라서 점액 유전자 활성화를 매개하는 신호전달 과정을 차단하는 약제나 방법이 개발된다면 과도한 점액분비를 치료할 수 있을 것으로 생각한다.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2002년도 창립10주년기념 및 국립독성연구원 의약품동등성평가부서 신설기념 국재학술대회:생물학적 동등성과 의약품 개발 전략을 위한 국제심포지움
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• pp.238-238
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• 2002

We studied whether kinase pathways are involved in TCDD-induced gene expression by treating specific kinase inhibitors ncluding MEK1 inhibitor PD98059, p38 inhibitor SB202190, PI-3 kinase inhibitor Wortmannin or LY294002 or protein tyrosine kinase inhibitor Genestein and then tested the effects of individual inhibitors on TCDD-induced gene expression of cytochromelAl gene (CYPlAl). Our results show that PD98059, MEK-1 inhibitor reduces dioxin-inducible transcription of CYPlAl. p44/p42MAPK, that is phosphorylated by Mek-1, are phosphorlylated by treatment of TCDD, peaking at lnM, 30min treatments. Overexpressions of p44/p42 MAPK dominant negative mutants suppress dioxin dependent transcription of DRE-driven reporter gene in a dose-dependent manner. Our results demonstrate that p44/p42 MAPK is essential for transcriptional activity of AHR/ARNT heterodimer. We found that PD98059 dose-dependently blocks TCDD-induced DRE binding of the AHR/ARNT heterodimer, thereby it reduces TCDD-induced gene expression. Therefore, our results indicate that Mek-1/p44/p42 MAPK pathway is involved in TCDD-induced gene expression, [This study was supported by a grant from Korean Research Foundation Grant (X01529)to H. Park]

• BMB Reports
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• 제46권4호
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• pp.213-218
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• 2013

Members of the colony stimulating factor cytokine family play important roles in macrophage activation and recruitment to inflammatory lesions. Among them, granulocyte-macrophage colony stimulating factor (GM-CSF) is known to be associated with immune response to mycobacterial infection. However, the mechanism through which Mycobacterium tuberculosis (MTB) affects the expression of GM-CSF is poorly understood. Using PMA-differentiated THP-1 cells, we found that MTB infection increased GM-CSF mRNA expression in a dose-dependent manner. Induction of GM-CSF mRNA expression peaked 6 h after infection, declining gradually thereafter and returning to its basal levels at 72 h. Secretion of GM-CSF protein was also elevated by MTB infection. The increase in mRNA expression and protein secretion of GM-CSF caused by MTB was inhibited in cells treated with inhibitors of p38 MAPK, mitogen-activated protein kinase kinase (MEK-1), and PI3-K. These results suggest that up-regulation of GM-CSF by MTB is mediated via the PI3-K/MEK1/p38 MAPK-associated signaling pathway.

• 한국발생생물학회지:발생과생식
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• 제27권2호
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• pp.77-89
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• 2023

Metformin is the most widely used anti-diabetic drug that helps maintain normal blood glucose levels primarily by suppressing hepatic gluconeogenesis in type II diabetic patients. We previously found that metformin induces apoptotic death in H4IIE rat hepatocellular carcinoma cells. Despite its anti-diabetic roles, the effect of metformin on hepatic de novo lipogenesis (DNL) remains unclear. We investigated the effect of metformin on hepatic DNL and apoptotic cell death in H4IIE cells. Metformin treatment stimulated glucose consumption, lactate production, intracellular fat accumulation, and the expressions of lipogenic proteins. It also stimulated apoptosis but reduced autophagic responses. These metformin-induced changes were clearly reversed by compound C, an inhibitor of AMP-activated protein kinase (AMPK). Interestingly, metformin massively increased the production of reactive oxygen species (ROS), which was completely blocked by compound C. Metformin also stimulated the phosphorylation of p38 mitogen-activated protein kinase (p38MAPK). Finally, inhibition of p38MAPK mimicked the effects of compound C, and suppressed the metformin-induced fat accumulation and apoptosis. Taken together, metformin stimulates dysregulated glucose metabolism, intracellular fat accumulation, and apoptosis. Our findings suggest that metformin induces excessive glucose-induced DNL, oxidative stress by ROS generation, activation of AMPK and p38MAPK, suppression of autophagy, and ultimately apoptosis.

• 대한의생명과학회지
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• 제12권3호
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• pp.249-254
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• 2006

It has been reported that liver is a very important organ to xenotransplantation. Pig is known to be a most suitable species in transplantation of human organs. However, the physiological function of pig hepatocytes is not clear elucidated. Epidermal growth factor (EGF) is known to be a mitogen in various cell systems. Thus, we examined the effect of EGF on cell proliferation and its related signal cascades in primary cultured pig hepatocytes. EGF stimulates cell proliferation in a dose (>1ng/ml) dependent manner. EGF-induced increase of $[^3H]-thymidine$ incorporation was blocked by AG 1478 ($10^{-6}M$, an EGF receptor antagonist) genistein and herbymycin A (tyrosine kinase inhibitors, $10^{-6}M$), suggesting the role of activation and tyrosine phosphorylation of EGF receptor. In addition, EGF-induced increase of $[^3H]-thymidine$ incorporation was prevented by neomycin $(10^{-4}M)$, U73122 $(10^{-5}M)$ (phospholipase C [PLC] inhibitors), staurosporine ($(10^{-8}M)$, or bisindolylmaleimide I $(10^{-6}M)$ (protein kinase C [PKC] inhibitors), suggesting the role of PLC and PKC. Moreover, EGF-induced increase of $[^3H]-thymidine$ incorporation was blocked by PD 98059 (a p44/42 mitogen activated protein kinase [MAPK] inhibitor), SB 203580 (a p38 MAPK inhibitor), and SP 600125 (a JNK inhibitor). EGF increased the translocation of PKC from cytosol to membrane fraction and activated p42/44 MAPK, p38 MAPK and JNK. In conclusion, EGF stimulates cell proliferation via PKC and MAPK in cultured pig hepatocytes.

• 동의생리병리학회지
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• 제19권2호
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• pp.501-507
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• 2005

Shikonin is a chemically characterized component of traditional herbal medicine, the root of Lithospermum erythrorhizon and has been shown to possess antitumor activities. Here we investigated anticancer potential of shikonin and its possible mechanism of action in LLC cells. Shikonin inhibited the proliferation of LLC cells in a concentration-dependent manner. It was also demonstrated that shikonin induced apoptosis in LLC cells by Annexin V staining and TUNEL staining analysis. Shikonin treatment was caused that decrease of Bcl-2, activation of caspases and cleavage of PARP. And shikonin also induced that the activation of mitogen-activated protein kinases (MAPKs), such as extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and p38. Interestingly, the cell proliferation inhibition induced by shikonin was recovered by specific inhibitors of JNK and p38 but the inhibitor of MEK, the upstream kinase of ERK, did not recover. Additionally, shikonin administration at doses of 5 mg/kg in C57BL/6 mice strongly inhibited the primary tumor growth of LLC. Taken together, these results suggest that shikonin may suppress LLC cell proliferation by inducing an apoptotic process via activation of caspases and MAPKs