• 제목/요약/키워드: pERK

검색결과 874건 처리시간 0.025초

Typha orientalis inhibits inflammatory cytokine expression through suppression of ERK phosphorylation in HMC-1 cells

  • Choi, In-Young;Na, Ho-Jeong;Um, Jae-Young;Kim, Hyung-Min;Hong, Seung-Heon;Sim, Kuk-Jin;Song, Bong-Keun;Nam, Gi-Hye;Choung, Se-Young;Jeong, Hyun-Ja
    • Advances in Traditional Medicine
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    • 제10권1호
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    • pp.7-12
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    • 2010
  • Typha orientalis' stem (TOS) is traditionally used as an herbal medicine for difficulty in urination, galactophoritis purulenta, whooping cough, and allergic dermatitis. However, its effect in experimental models remains unknown. Here, we report the effect of TOS on the phorbol 12-myristate 13-acetate (PMA) plus calcium ionophore A23187-induced inflammatory cytokine production and extracellular signal-regulated kinase (ERK) activation in the human mast cell line, HMC-1. TOS inhibited PMA plus A23187-induced cytokines such as tumor necrosis factor-alpha (TNF-$\alpha$) and interleukin (IL)-6. Maximal inhibition rate of TNF-$\alpha$ and IL-6 production by TOS (1 mg/ml) was about 44.02%, and 45.20%, respectively (P < 0.05). In addition, TOS inhibited the expression of TNF-$\alpha$ and IL-6 mRNA under the same condition. Moreover, TOS partially blocked PMA plus A23187-induced ERK phosphorylation. These results suggested TOS could inhibit the cytokine production through blocking of ERK activity.

HMGB1 regulates autophagy through increasing transcriptional activities of JNK and ERK in human myeloid leukemia cells

  • Zhao, Mingyi;Yang, Minghua;Yang, Liangchun;Yu, Yan;Xie, Min;Zhu, Shan;Kang, Rui;Tang, Daolin;Jiang, Zhigang;Yuan, Wuzhou;Wu, Xiushan;Cao, Lizhi
    • BMB Reports
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    • 제44권9호
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    • pp.601-606
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    • 2011
  • HMGB1 is associated with human cancers and is an activator of autophagy which mediates chemotherapy resistance. We here show that the mRNA levels of HMGB1 are high in leukemia cells and it is involved in the progression of childhood chronic myeloid leukemia (CML). HMGB1 decreases the sensitivity of human myeloid leukemia cells K562 to anti-cancer drug induced death through up-regulating the autophagy pathway, which is confirmed by the observation with an increase in fusion of autophagosomes and autophagolysosomes. When overexpressing HMGB1, both mRNA levels of Beclin-1, VSP34 and UVRAG which are key genes involved in mammalian autophagy and protein levels of p-Bcl-2 and LC3-II are increased. Luciferase assays document that over-expression of HMGB1 increases the transcriptional activity of JNK and ERK, which may be silenced by siRNA. The results suggest that HMGB1 regulates JNK and ERK required for autophagy, which provides a potential drug target for therapeutic interventions in childhood CML.

Involvement of ERK1/2 and JNK Pathways in 17${\beta}-estradiol$ Induced Kir6.2 and SK2 Upregulation in Rat Osteoblast-like Cells

  • Kim, Jung-Wook;Yang, Eun-Kyoung
    • The Korean Journal of Physiology and Pharmacology
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    • 제10권4호
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    • pp.199-205
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    • 2006
  • The functional expression of potassium $(K^+)$ channels has electrophysiologically been studied in bone cells from several species, however, their identity and regulation of gene expressions in bone cells are not well known. In the present study, to investigate how $K^+$ channel expressions are regulated by estrogen, we measured changes of transcript levels of various $Ca^{2+}$-activated ($K_{Ca}$) and ATP-sensitive $K^+$ channels in rat osteoblastic ROS 17/2.8 cells after treatment with estrogen. Application of 17${\beta}$-estradiol $(E_2)$ for 24 h and 48 h increased mRNA and protein expressions of inwardly rectifying $K^+$ channel (Kir) 6.2 and type 2 small conductance $K_{Ca}$ channel (SK2), respectively. Combined treatment of cells with 17${\beta}-E_2$ and ICI 182,780, a pure antiestrogen, suppressed 17${\beta}-E_2$-induced alterations of SK2 and Kir6.2 mRNA levels. In addition, treatment of cells with U0126, a specific inhibitor of extracellular receptor kinases (ERK)1/2, and SP600125, a specific inhibitor of c-jun N-terminal kinase (JNK) blocked the enhancing effects of 17${\beta}-E_2$ on SK2 and Kir6.2 protein expressions. On the other hand, blocking of p38 mitogen-activated protein kinase had no effect. Taken together, these results indicate that 17${\beta}-E_2$ modulates SK2 and Kir6.2 expressions through the estrogen receptor, involving ERK1/2 and JNK activations.

Radicicol Inhibits iNOS Expression in Cytokine-Stimulated Pancreatic Beta Cells

  • Youn, Cha Kyung;Park, Seon Joo;Li, Mei Hong;Lee, Min Young;Lee, Kun Yeong;Cha, Man Jin;Kim, Ok Hyeun;You, Ho Jin;Chang, In Youp;Yoon, Sang Pil;Jeon, Young Jin
    • The Korean Journal of Physiology and Pharmacology
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    • 제17권4호
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    • pp.315-320
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    • 2013
  • Here, we show that radicicol, a fungal antibiotic, resulted in marked inhibition of inducible nitric oxide synthase (iNOS) transcription by the pancreatic beta cell line MIN6N8a in response to cytokine mixture (CM: TNF-${\alpha}$, IFN-${\gamma}$, and IL-$1{\beta}$). Treatment of MIN6N8a cells with radicicol inhibited CM-stimulated activation of NF-${\kappa}B$/Rel, which plays a critical role in iNOS transcription, in a dose-related manner. Nitrite production in the presence of PD98059, a specific inhibitor of the extracellular signal-regulated protein kinase-1 and 2 (ERK1/2) pathway, was dramatically diminished, suggesting that the ERK1/2 pathway is involved in CM-induced iNOS expression. In contrast, SB203580, a specific inhibitor of p38, had no effect on nitrite generation. Collectively, this series of experiments indicates that radicicol inhibits iNOS gene expression by blocking ERK1/2 signaling. Due to the critical role that NO release plays in mediating destruction of pancreatic beta cells, the inhibitory effects of radicicol on iNOS expression suggest that radicicol may represent a useful anti-diabetic activity.

Inhibition of Trypsin-Induced Mast Cell Activation by Water Fraction of Lonicera japonica

  • Kang, Ok-Hwa;Choi, Yeon-A;Park, Hye-Jung;Lee, Joo-Young;Kim, Dae-Ki;Choi, Suck-Chei;Kim, Tae-Hyun;Nah, Yong-Ho;Yun, Ki-Jung;Choi, Suck-Jun;Kim, Young-Ho;Bae, Ki-Hwan;Lee, Young-Ml
    • Archives of Pharmacal Research
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    • 제27권11호
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    • pp.1141-1146
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    • 2004
  • Lonicera japonica Thunb.(Caprifoliaceae) has long been known as an anti-inflammatory. In the present study, the effect of water fraction of Lonicera japonica (LJ) on trypsin-induced mast cell activation was examined. HMC-1 cells were stimulated with trypsin (100 nM) in the presence or absence of LJ (10, 100, and 1000 $\mu$ g/mL). TNF-$\alpha$ and tryptase production were measured by enzyme-linked immunosorbent assay (ELISA) and reverse transcription-PCR. Extracellular signal-regulated kinase (ERK) phosphorylation was assessed by Western blot. Trypsin activity was measured by using Bz-DL-Arg-p-nitroanilide (BAPNA) as substrate. LJ (10, 100, and 1000 $\mu$g/mL) inhibited TNF-$\alpha$ secretion in a dose-dependent manner. LJ (10, 100, and 1000 $\mu$g/mL) also inhibited TNF-$\alpha$ and tryptase mRNA expression in trypsin-stimulated HMC-1. Furthermore, LJ inhibited trypsin-induced ERK phosphorylation. However, LJ did not affect the trypsin activity even 1000 $\mu$g/mL. These results indicate that LJ may inhibit trypsin-induced mast cell activation through the inhibition of ERK phosphorylation than the inhibition of trypsin activity.

산약의 멜라노마 세포(B16F10)에서 MITF, TRP-1, TRP-2, Tyrosinase, PKA, ERK 발현 억제 효과 (Inhibitory Efficacy of Dioscoreae Rhizoma on MITF, TRP-1, TRP-2, Tyrosinase, PKA and ERK Expression in Melanoma Cells (B16F10))

  • 이수연;유단희;주다혜;이진영
    • 대한본초학회지
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    • 제30권4호
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    • pp.95-100
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    • 2015
  • Objectives : The purpose of this study was to research the whitening effects and developing by cosmetics of the extract fromDioscoreae Rhizoma, which is one of the most popular health-promoting herb in herbal medications.Methods : We performed tyrosinase inhibition assay, reverse transcription-polymerase chain reaction (RT-PCR) and western blot for whitening effects. Also we measured MTT assay for cell viability.Results : The results were obtained as follows : For whitening effect, tyrosinase inhibition rate of extract fromDioscoreae Rhizomashowed more than 42.28% at 1,000 ㎍/㎖ concentration. Cell toxicity effect on melanoma cells (B16F10) of extract fromDioscoreae Rhizomashowed 81.97% with toxicity at 50 ㎍/㎖ concentration. So we were measured at a concentrations of 5, 10 and 50 ㎍/㎖ in all experiments involving cell. In addition, whitening related mRNAs including microphthalmia associated transcription factor (MITF), tyrosinase related protein-1 (TRP-1), tyrosinase related protein-2 (TRP-2), tyrosinase were reduced byDioscoreae Rhizoma. We also foundDioscoreae Rhizomatransiently decreased protein kinase A (PKA) which is known to be upstream to the down regulation of MITF and tyrosinase. But phosphorylation of extracellular signal related kinase (pERK) were increased byDioscoreae Rhizoma. These results imply thatDioscoreae Rhizomadecrease melanogenesis via ERK activation and subsequent down regulation of MITF and tyrosinase.Conclusions : Therefore, all these findings suggested the potent usage ofDioscoreae Rhizomaas materials of functional cosmetics by confirming whitening activity related with melanin content.

Quercetin-3-O-β-D-Glucuronide Suppresses Lipopolysaccharide-Induced JNK and ERK Phosphorylation in LPS-Challenged RAW264.7 Cells

  • Park, Jin-Young;Lim, Man-Sup;Kim, Song-In;Lee, Hee Jae;Kim, Sung-Soo;Kwon, Yong-Soo;Chun, Wanjoo
    • Biomolecules & Therapeutics
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    • 제24권6호
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    • pp.610-615
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    • 2016
  • Quercetin, a flavonol, has been reported to exhibit a wide range of biological properties including anti-oxidant and anti-inflammatory activities. However, pharmacological properties of quercetin-3-O-${\beta}$-D-glucuronide (QG), a glycoside derivative of quercetin, have not been extensively examined. The objective of this study is to elucidate the anti-inflammatory property and underlying mechanism of QG in lipopolysaccharide (LPS)-challenged RAW264.7 macrophage cells in comparison with quercetin. QG significantly suppressed LPS-induced extracellular secretion of pro-inflammatory mediators such as nitric oxide (NO) and $PGE_2$, and pro-inflammatory protein expressions of iNOS and COX-2. To elucidate the underlying mechanism of the anti-inflammatory property of QG, involvement of MAPK signaling pathways was examined. QG significantly attenuated LPS-induced activation of JNK and ERK in concentration-dependent manners with a negligible effect on p38. In conclusion, the present study demonstrates QG exerts anti-inflammatory activity through the suppression of JNK and ERK signaling pathways in LPS-challenged RAW264.7 macrophage cells.

RASAL1 Attenuates Gastric Carcinogenesis in Nude Mice by Blocking RAS/ERK Signaling

  • Chen, Hong;Zhao, Ji-Yi;Qian, Xu-Chen;Cheng, Zheng-Yuan;Liu, Yang;Wang, Zhi
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권3호
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    • pp.1077-1082
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    • 2015
  • Recent studies have suggested that the RAS protein activator like-1 (RASAL1) functions as a tumor suppressor in vitro and may play an important role in the development of gastric cancer. However, whether or not RASAL1 suppresses tumor growth in vivo remains to be determined. In the present study, we investigated the role of RASAL1 in gastric carcinogenesis using an in vivo xenograft model. A lentiviral RASAL1 expression vector was constructed and utilized to transfect the human poorly differentiated gastric adenocarcinoma cell line, BGC-823. RASAL1 expression levels were verified by quantitative real-time RT-PCR and Western blotting analysis. Then, we established the nude mice xenograft model using BGC-823 cells either over-expressing RASAL1 or normal. After three weeks, the results showed that the over-expression of RASAL1 led to a significant reduction in both tumor volume and weight compared with the other two control groups. Furthermore, in xenograft tissues the increased expression of RASAL1 in BGC-823 cells caused decreased expression of p-ERK1/2, a downstream moleculein the RAS/RAF/MEK/ERK signal pathway. These findings demonstrated that the over-expression of RASAL1 could inhibit the growth of gastric cancer by inactivation of the RAS/RAF/MEK/ERK pathway in vivo. This study indicates that RASAL1 may attenuate gastric carcinogenesis.

Soft corals collected from Jeju Island inhibits the α-MSH-induced melanogenesis in B16F10 cells through activation of ERK

  • Sanjeewa, K. K. Asanka;Park, Young-jin;Fernando, I. P. Shanura;Ann, Yong-Seok;Ko, Chang-Ik;Wang, Lei;Jeon, You-Jin;Lee, WonWoo
    • Fisheries and Aquatic Sciences
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    • 제21권9호
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    • pp.21.1-21.8
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    • 2018
  • In the present study, we first evaluated the melanin inhibitory effect of four crude 70% ethanol extracts separated from soft corals abundantly growing along the seawaters of Jeju Island, South Korea, including Dendronephthya castanea (DC), Dendronephthya gigantea (DG), Dendronephthya puetteri (DP), and Dendronephthya spinulosa (DS). Among the four ethanol extracts, the ethanol extract of DP (DPE) did not possess any cytotoxic effect on B16F10 cells. However, all other three extracts showed a cytotoxic effect. Also, DPE reduced the melanin content and the cellular tyrosinase activity without cytotoxicity, compared to the ${\alpha}-MSH$-stimulated B16F10 cells. Specifically, DPE downregulated the expression levels of tyrosinase and microphthalmia-associated transcription factor by activating the ERK signaling cascade in ${\alpha}-MSH$-stimulated B16F10 cells. Interestingly, the melanin inhibitory effect of DPE was abolished by the co-treatment of PD98059, an ERK inhibitor. According to these results, we suggest that DPE has whitening capacity with the melanin inhibitory effects by activating ERK signaling and could be used as a potential natural melanin inhibitor for cosmeceutical products.

숙지황(熟地黃) 추출물이 $H_2O_2$에 의해 유도된 ECV304 세포의 apoptosis에 미치는 영향 (Protective Effect of Rehmanniae Radix Preparata Extract on $H_2O_2$-induced Apoptosis of ECV304 Cells)

  • 김인규;주성민;박진모;전병제;양현모;김원신;전병훈
    • 동의생리병리학회지
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    • 제23권1호
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    • pp.76-83
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    • 2009
  • Rehmannia Radix Preparata (RRP) used to nourish Eum and enrich blood for consumptive fever, aching, and limpness of the loins and knees, and to replenish essence for tinnitus, premature greying of beard and hair. In the present study, we studied about the protective effect of RRP on hydrogen peroxide-induced oxidative stress in human vascular endothelial cells. ECV304 cells were preincubated with RRP (100, 200, 300 and $400{\mu}g/m{\ell}$) for 12hr and then treated with $600{\mu}M$ $H_2O_2$ for 12hr. The protective effects of RRP on $H_2O_2$-induced apoptosis in ECV304 cells was determined by using MTT assay, FDA-PI staining, flow cytometric analysis, caspase-3 activity assay, ROS assay and western blot. The results of this experiment showed that RRP inhibited $H_2O_2$-induced apoptosis and ROS production in ECV304 cells. Moreover, RRP increased ERK activation that decreased in $H_2O_2$-treated ECV304 cells, and inhibited p38 and JNK activation. Furthermore, RRP increased expression of heme oxygenase-1 (HO-1) in $H_2O_2$-treated ECV304 cells. Also, HO-1 protein expression induced by RRP was reduced by the addition of ERK inhibitor (PD98059) in $H_2O_2$-treated ECV304 cells. These results suggest that protective effect of RRP on $H_2O_2$-induced oxidative stress in ECV304 cells may be associated with increase of ERK activation and HO-1 protein, and reduction of p38 and JNK activation.