• The Korean Journal of Physiology and Pharmacology
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• 제17권3호
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• pp.181-187
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• 2013

Reactive oxygen species (ROS) are generated in various cells, including vascular smooth muscle and endothelial cells, and regulate ion channel functions. $K_{Ca}3.1$ plays an important role in endothelial functions. However, the effects of superoxide and hydrogen peroxide radicals on the expression of this ion channel in the endothelium remain unclear. In this study, we examined the effects of ROS donors on $K_{Ca}3.1$ expression and the $K^+$ current in primary cultured human umbilical vein endothelial cells (HUVECs). The hydrogen peroxide donor, tert-butyl hydroperoxide (TBHP), upregulated $K_{Ca}3.1$ expression, while the superoxide donors, xanthine/xanthine oxidase mixture (X/XO) and lysophosphatidylcholine (LPC), downregulated its expression, in a concentration-dependent manner. These ROS donor effects were prevented by antioxidants or superoxide dismustase. Phosphorylated extracellular signal-regulated kinase (pERK) was upregulated by TBHP and downregulated by X/XO. In addition, repressor element-1-silencing transcription factor (REST) was downregulated by TBHP, and upregulated by X/XO. Furthermore, $K_{Ca}3.1$ current, which was activated by clamping cells with 1 ${\mu}M$ $Ca^{2+}$ and applying the $K_{Ca}3.1$ activator 1-ethyl-2-benzimidazolinone, was further augmented by TBHP, and inhibited by X/XO. These effects were prevented by antioxidants. The results suggest that hydrogen peroxide increases $K_{Ca}3.1$ expression by upregulating pERK and downregulating REST, and augments the $K^+$ current. On the other hand, superoxide reduces $K_{Ca}3.1$ expression by downregulating pERK and upregulating REST, and inhibits the $K^+$ current. ROS thereby play a key role in both physiological and pathological processes in endothelial cells by regulating $K_{Ca}3.1$ and endothelial function.

• 생명과학회지
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• 제26권1호
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• pp.117-122
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• 2016

본 연구에서는 고구마 소주로부터 획득한 에탄올 추출물 및 순차적 유기용매 분획물을 제조하고, 이들 시료가 LPS로 활성화된 마우스 대식세포 RAW 264.7 세포주에서 nitric oxide (NO) 생산과 세포생존율에 미치는 영향을 연구하였다. 처리한 시료 중 ethyl acetate 분획물(KSD-E8-3) 처리군에서 LPS로 염증 유도된 RAW 264.7 세포주의 생존율에는 영향 없이 NO 생성을 현저하게 감소 시킴을 확인하였다. 또한 분획물 KSD-E8-3 처리에 의해서 염증매개 인자인 COX-2, iNOS 그리고 TNF-alpha의 유전자의 발현이 감소되었으며, iNOS 단백질의 발현이 현저히 감소됨을 Western blot으로 확인하였다. 또한, 분획물 KSD-E8-3 처리에 의해 세포내 대표적인 신호 전달 단백질인 3가지의 MAPK 단백질(p38, JNK, ERK1/2)의 인산화가 모두 억제됨을 확인하였다. 종합적으로, 이러한 연구결과는 고구마 소주 주박에 함유된 생리활성 물질에 의한 항염증 활성 및 작용 기전을 이해하는데 도움을 줄 것으로 기대된다.

• Journal of Ginseng Research
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• 제41권2호
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• pp.227-231
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• 2017

Background: Ginsenosides are active components of Panax ginseng that exert various health benefits including kidney protection effect. The medicinal activity of ginsenosides can be enhanced by modulating their stereospecificity by heat processing. Ginsenosides Rk2 and Rh3 represent positional isomers of the double bond at C-20(21) or C-20(22). Methods: The present study investigated the kidney-protective effects of ginsenosides Rk2 and Rh3 against cisplatin, a platinum based anticancer drug, induced apoptotic damage in renal proximal LLC-PK1 cells. Results: As a result, ginsenoside Rh3 shows a stronger protective effect than that shown by Rk2. Cisplatin-induced elevated protein levels of phosphorylated c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), p38, and cleaved caspase-3 decreased after cotreatment with ginsenoside Rh3. The increase in the percentage of apoptotic LLC-PK1 cells induced by cisplatin treatment also significantly reduced after cotreatment with ginsenoside Rh3. Conclusion: These results demonstrate that inhibition of the JNK and ERK mitogen-activated protein kinase signaling cascade plays a critical role in mediating the renoprotective effect of ginsenoside Rh3.

• 대한본초학회지
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• 제21권1호
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• pp.33-42
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• 2006

Objectives : The purpose of this study was to investigate the anticancer effects of Bodusan (BDS) on SNU-1 cells, a human gastric cancer cell line. Methods : To study the cytotoxic effect of BDS on SNU-1 cells, the cells were treated with various concentrations of BDS and then cell viability was determined by XTT reduction method and trypan blue exclusion assay. The typical signs of apoptosis, was examined by western blot analysis. BDS-induced MAPK activation was also examined by Western blot for phosphorylated ERK and p38. Results : BDS reduced proliferation of SNU-1 cells in a dose-dependent manner and decreased procaspase 3 level in a dose-dependent manner and induced the clevage of PARP at concentration > 500 ${\mu}g/ml$. BDS also triggered the mitochondrial apoptotic signaling by increasing the release of cytochrome C from mitochondria to cytosol and reducing the level of anti-apoptotic Bcl-2. BDS significantly decreased ERK phosphorylation and increased p38 phosphorylation in a dose-dependent manner. Futhermore, BDS treatment up-regulated p53 and p21waf expression in a dose-dependent manner. Conclusion : BDS-induced apoptosis is MAP kinase-dependent apoptoric pathway and arrested SNU-1 cells at the G0/G1 of cell cycle. These results suggest that BDS is potentially useful as a chemotherapeutic agent in human gastric cancer.

• The Korean Journal of Physiology and Pharmacology
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• 제12권4호
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• pp.171-176
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• 2008

Heat shock proteins (HSPs) serve as molecular chaperones and play a role in cell protection from damage in response to stress stimuli. The aim of this article is to investigate whether HSP22 affects IL-8 expression in vascular smooth muscle cells (VSMCs), and which cellular factors are involved in the HSP-mediated IL-8 induction in that cell type in terms of mitogen activated protein kinase (MAPK) and transcription element. Exposure of aortic smooth muscle cells (AoSMCs) to HSP22 not only enhanced IL-8 release but also induced IL-8 transcript via promoter activation. HSP22 activated ERK and p38 MAPK in AoSMCs. HSP22-induced IL-8 release was inhibited by U0126, but not by SB202190. A mutation in the IL-8 promoter region at the binding site of NF-${\kappa}$ B, but not AP-1 or C/EBP, impaired promoter activation in response to HSP22. Delivery of I ${\kappa}$ B, but not dominant negative c-Jun, lowered HSP22-induced IL-8 release from AoSMCs. These results suggest that HS P22 induces IL-8 in VSMCs via ERK1/2, and that transcription factor NF-kB may be required for the HSP22-induced IL-8 up-regulation.

• Journal of Acupuncture Research
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• 제36권4호
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• pp.220-229
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• 2019

Background: The therapeutic potential of Bee Venom Pharmacopuncture (BVP) on acute ischemic cerebral infraction was determined in mice in vivo and in vitro. Methods: Analysis of acute ischemic cerebral infraction was performed using 7 week old male ICR mice (n = 20) and microglial BV-2 cells. Bee venom ($5{\mu}g/kg$) was injected into the caudal vein of middle cerebral artery occlusion (MCAo) mice (1 hour after reperfusion, 3 hours after MCAo probe insertion), and also used to treat LPS-stimulated microglial BV-2 cells (1, 2, $5{\mu}g/mL$). Markers of inflammation were monitored. Results: NO declined statistically significantly in BVP treated MCAo mice compared to the untreated MCAo group (p < 0.05). Compared to the MCAo group, the BVP-treated MCAo group showed a decreased production volume of malondialdehyde, but an increased glutathione/oxidized glutathione ratio. Compared to the untreated MCAo group, the BVP treated MCAo group showed a statistically significant decline in TNF and $IL-1{\beta}$ levels (p < 0.05). BVP inhibited the levels of p65, p50, $p-I{\kappa}B-{\alpha}$, and levels of p-ERK1/2, p-JNK2, p-P38 declined. Conclusion: BVP is effective at dampening the inflammatory response in vivo and in vitro and may supplement rt-PA treatment.

• 동의신경정신과학회지
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• 제21권1호
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• pp.125-144
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• 2010

Objectives: The purpose of this study was to characterize the effect of the fraction of Korean mountain ginseng folium (FKG) on the learning and memory impairments induced by scopolamine. Methods: The memory ameliorating effect of FKG was investigated using a passive avoidance test, the Y-maze test, and the Morris water maze test in mice. Drug-induced amnesia was induced by treating animals with scopolamine(1mg/kg, i.p.). Results: FKG (2 or 4mg/kg, p.o.) administration significantly reversed scopolamine-induced cognitive impairments in mice by the passive avoidance test and the Y-maze test(P<0.05), and also improved escape latency in the Morris water maze test at 2 or 4mg/kg(P<0.05). Although FKG has little inhibitory activity for AChE (IC50 value; 1847 ${\mu}g/ml$) in an invitro study, phosphorylated extracellular signal-regulated kinase(pERK) was increased by the administration of FKG inhippocampus on immunohistochemistry. Conclusions: These results suggest that FKG may be a useful cognitive impairment treatment, and its beneficial effects are mediated, in part, via activation of ERK pathway.

• BMB Reports
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• 제42권11호
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• pp.758-763
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• 2009

Cancer-associated antigen (CAGE) induces the expression of matrix metalloproteinase-2 (MMP-2) by activating Akt, which in turn interacts with inhibitory kappa kinase $\beta$ ($I{\kappa}K{\beta}$) to activate nuclear factor ${\kappa}B$ (NF-${\kappa}B$). Akt and p38 mitogen activated protein kinase (p38 MAPK) are necessary for CAGE-mediated induction of the AP-1 subunit JunB, whereas extracellular regulated kinase (ERK) is necessary for the induction of fos-related antigen-1 (Fra-1). Induction of MMP-2 by CAGE requires activator of protein-1 (AP-1) to be bound. Specific binding of JunB to MMP-2 promoter sequences was shown by chromatin immunoprecipitation (ChIP) analysis.

• Journal of Nutrition and Health
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• 제49권4호
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• pp.241-246
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• 2016

Purpose: Aloe-emodin (AE), an ingredient of aloe, is known to exhibit anti-inflammatory activities. However, little is known about the underlying molecular mechanisms of its inflammatory modulatory activity in vitro. In the present study, we investigated the anti-inflammatory potential of AE using $Pam_3CSK_4$-stimulated macrophages. Methods: RAW 264.7 macrophages were treated with AE (0~20 mM) for 1 h, followed by treatment with $Pam_3CSK_4$ for 1 h. After incubation, mRNA expression levels of cytokines were measured. The effect of AE on TLR2-related molecules was also investigated in $Pam_3CSK_4$-stimulated RAW 264.7 macrophages. Results: AE attenuated $Pam_3CSK_4$-stimulated expression of proinflammatory cytokines, including tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), interleukin-6 (IL-6), and interleukin-$1{\beta}$ ($IL-1{\beta}$) in RAW 264.7 macrophages. Two concentrations of AE ($10{\mu}M$ and $20{\mu}M$) effectively reduced mRNA expression of TLR2 by 41.18% and 54.43%, respectively, compared to that in control cells (p < 0.05). AE also decreased nuclear factor-kappa B ($NF-{\kappa}B$) activation and mitogen-activated protein kinase (MAPK) phosphorylation. Phosphorylation levels of ERK1/2, p38, and JNK were markedly reduced by $20{\mu}M$ AE. In particular, AE decreased phosphorylation of ERK in a dose-dependent manner in $Pam_3CSK_4$-stimulated RAW 264.7 macrophages. Conclusion: Our data indicate that AE exerts its anti-inflammatory effect by suppressing TLR2-mediated activation of $NF-{\kappa}B$ and MAPK signaling pathways in macrophages.

• The Korean Journal of Physiology and Pharmacology
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• 제15권1호
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• pp.1-7
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• 2011

Many anticancer agents as well as ionizing radiation have been shown to induce autophagy which is originally described as a protein recycling process and recently reported to play a crucial role in various disorders. In HCT116 human colon cancer cells, we found that curcumin, a polyphenolic phytochemical extracted from the plant Curcuma longa, markedly induced the conversion of microtubule-associated protein 1 light chain 3 (LC3)-I to LC3-II and degradation of sequestome-1 (SQSTM1) which is a marker of autophagosome degradation. Moreover, we found that curcumin caused GFP-LC3 formation puncta, a marker of autophagosome, and decrease of GFP-LC3 and SQSTM1 protein level in GFP-LC3 expressing HCT116 cells. It was further confirmed that treatment of cells with hydrogen peroxide induced increase of LC3 conversion and decrease of GFP-LC3 and SQSTM1 levels, but these changes by curcumin were almost completely blocked in the presence of antioxidant, N-acetylcystein (NAC), indicating that curcumin leads to reactive oxygen species (ROS) production, which results in autophagosome development and autolysosomal degradation. In parallel with NAC, SQSTM1 degradation was also diminished by bafilomycin A, a potent inhibitor of autophagosome-lysosome fusion, and cell viability assay was further confirmed that cucurmin-induced cell death was partially blocked by bafilomycin A as well as NAC. We also observed that NAC abolished curcumin-induced activation of extracelluar signal-regulated kinases (ERK) 112 and p38 mitogen-activated protein kinases (MAPK), but not Jun N-terminal kinase (JNK). However, the activation of ERK1/2 and p38 MAPK seemed to have no effect on the curcumin-induced autophagy, since both the conversion of LC3 protein and SQSTM1 degradation by curcumin was not changed in the presence of NAC. Taken together, our data suggest that curcumin induced ROS production, which resulted in autophagic activation and concomitant cell death in HCT116 human colon cancer cell. However, ROS-dependent activation of ERK1/2 and p38 MAPK, but not JNK, might not be involved in the curcumin-induced autophagy.