• Title/Summary/Keyword: Cell signaling

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Alaria esculenta Extract Protects against Oxidative Damage by Inducing Heme Oxygenase-1 Expression via Akt and Nrf2

  • Choi, Chun-Yeon;Jo, Guk-Heui;Lee, Jung-Im;Seo, Young-Wan;Han, Tae-Jun;Choi, Il-Whan;Liu, Kwang-Hyeon;Oh, Sang-Taek;Kim, Dong-Eun;Jang, Won-Hee;Seog, Dae-Hyun;Park, Yeong-Hong;Yea, Sung-Su
    • Molecular & Cellular Toxicology
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    • v.5 no.2
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    • pp.120-125
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    • 2009
  • Alaria esculenta is a brown seaweed found in the Arctic. This study investigated the protective effect of A. esculenta extract (AEE) against oxidant-mediated injury and its mode of action in RAW264.7 macrophages. The methyl thiazolyl tetrazolium (MTT) assay showed that $H_2O_2$ treatment reduced cell viability, whereas AEE protected cells from $H_2O_2$-mediated cytotoxicity in a dose-dependent manner. Because heme oxygenase-1 (HO-1) is known to protect cells against oxidative damage, we investigated the effect of AEE on HO-1 gene expression and HO enzyme activity. The protective effect of AEE against $H_2O_2$-induced injury was correlated with increased HO enzyme activity. AEE also induced HO-1 mRNA and protein expression, as determined RT-PCR and Western blotting, respectively. To characterize the mechanisms by which AEE induces HO-1 gene expression, we examined the effect of AEE on the nuclear translocation of NF-E2-related factor-2 (Nrf2) and Akt phosphorylation. AEE treatment activated upstream signaling for HO-1 gene expression, including the nuclear translocation of Nrf2 and Akt phosphorylation. Collectively, these results suggest that AEE has anti-oxidant activity that is mediated, at least in part, via the activation of Nrf2 and Akt and the subsequent induction of HO-1 gene expression.

Allium Hookeri Extract Enhances Glucose Uptake through GLUT4 Up-regulation in 3T3-L1 Cells (GLUT4 상향조절을 통한 Allium hookeri 추출물의 3T3-L1 세포 내 포도당 흡수 증진 효과)

  • Kang, Young Eun;Choi, Kyeong-Mi;Park, Eunjin;Jung, Won-Beom;Jeong, Heejin;Yoo, Hwan-Soo
    • Journal of Life Science
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    • v.27 no.3
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    • pp.289-294
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    • 2017
  • Diabetes mellitus is associated with insulin resistance, which leads to down-regulation of insulin signaling and the decreased glucose uptake. Adipocytes are sensitive to insulin, and closely implicated in insulin resistance and diabetes. Insulin stimulates differentiation of preadipocytes to adipocytes, and increases glucose transport. Allium species have been used as traditional medicine and health-promoting foods. Allium hookeri (A. hookeri) is reported to improve the pancreatic ${\beta}-cell$ damage and exhibit pancreatic anti-inflammatory activity in streptozotocin-induced diabetic rats. We investigated whether A. hookeri extract (AHE) may stimulate glucose uptake in adipocytes through increasing insulin sensitivity. AHE enhanced fat accumulation, a differentiation biomarker, under the partial induction of differentiation by insulin. $PPAR{\gamma}$, a transcription factor highly expressed in adipocytes, promotes adipocyte differentiation and insulin sensitivity. AHE increased the differentiation of preadipocytes through up-regulation of $PPAR{\gamma}$. The activation of $PPAR{\gamma}$ increases the GLUT4 expression during adipocyte differentiation. GLUT4 is responsible for glucose uptake into the adipocytes. AHE increased the expression of GLUT4 in adipocytes, and subsequently enhanced the insulin-stimulated glucose uptake. These results suggest that AHE promotes adipocyte differentiation through activation of $PPAR{\gamma}$, and leads to enhance glucose uptake in adipocytes along with GLUT4 up-regulation. Thus, AHE may be effective for the insulin-sensitizing and anti-diabetic activities.

Reconstructed Adeno-Associated Virus with the Extracellular Domain of Murine PD-1 Induces Antitumor Immunity

  • Elhag, Osama A.O.;Hu, Xiao-Jing;Wen-Ying, Zhang;Li, Xiong;Yuan, Yong-Ze;Deng, Ling-Feng;Liu, De-Li;Liu, Ying-Le;Hui, Geng
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.8
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    • pp.4031-4036
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    • 2012
  • Background: The negative signaling provided by interactions of the co-inhibitory molecule, programmed death-1 (PD-1), and its ligands, B7-H1 (PD-L1) and B7-DC (PD-L2), is a critical mechanism contributing to tumor evasion; blockade of this pathway has been proven to enhance cytotoxic activity and mediate antitumor therapy. Here we evaluated the anti-tumor efficacy of AAV-mediated delivery of the extracellular domain of murine PD-1 (sPD-1) to a tumor site. Material and Methods: An rAAV vector was constructed in which the expression of sPD-1, a known negative regulator of TCR signals, is driven by human cytomegalovirus immediate early promoter (CMV-P), using a triple plasmid transfection system. Tumor-bearing mice were then treated with the AAV/sPD1 construct and expression of sPD-1 in tumor tissues was determined by semi quantitative RT-PCR, and tumor weights and cytotoxic activity of splenocytes were measured. Results: Analysis of tumor homogenates revealed sPD-1 mRNA to be significantly overexpressed in rAAV/sPD-1 treated mice as compared with control levels. Its use for local gene therapy at the inoculation site of H22 hepatoma cells could inhibit tumor growth, also enhancing lysis of tumor cells by lymphocytes stimulated specifically with an antigen. In addition, PD-1 was also found expressed on the surfaces of activated CD8+ T cells. Conclusion: This study confirmed that expression of the soluble extracellular domain of PD-1 molecule could reduce tumor microenvironment inhibitory effects on T cells and enhance cytotoxicity. This suggests that it might be a potential target for development of therapies to augment T-cell responses in patients with malignancies.

Expression and Clinical Significance of mTOR in Surgically Resected Non-small Cell Lung Cancer Tissues: a Case Control Study

  • Liu, Zhe;Wang, Liang;Zhang, Li-Na;Wang, Yue;Yue, Wen-Tao;Li, Qi
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.12
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    • pp.6139-6144
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    • 2012
  • Aims: Mammalian target of rapamycin (mTOR) is master regulator of the PI3K/Akt/mTOR pathway and plays an important role in NSCLCs. Here we characterized mRNA and protein expression levels of mTOR and its functional associated molecules including PTEN, IGF-1R and 4EBP1 in surgically resected NSCLCs. Methods: Fifty-four patients with NSCLCs who underwent pulmonary resection were included in current study. mRNA levels of mTOR, PTEN, IGF-1R, and 4EBP1 were evaluated by RT-PCR and protein expression of mTOR, PTEN, and IGF-1R by immunohistochemistry (IHC). Association of expression of the relevant molecules with clinical characteristics, as well as correlations between mTOR and PTEN, 4EBP1 and IGF-1R were also assessed. Results: The results of RT-PCR showed that in NSCLCs, the expression level of mTOR increased, while PTEN, 4EBP1 and IGF-1R decreased. Statistical analysis indicated high IGF-1R expression was correlated with advanced clinical stage (stage III) and PTEN expression was reversely associated with tumor size (P=0.16). The results of IHC showed mTOR positive staining in 51.8% of cases, while IGF-1R positive staining was found in 83.3% and loss of PTEN in 46.3%. Protein expression of mTOR was correlated with its regulators, PTEN and IGF-1R, to some extent. Conclusions: Abnormal activation of mTOR signaling, high expression of IGF-1R, and loss of PTEN were observed in resected NSCLC specimens. The poor expression agreement of mTOR with its regulators, PTEN, and IGF-1R, implied that combination strategy of mTOR inhibitors with other targets hold significant potential for NSCLC treatment.

Anti-oxidative Effect of Chungsimyeonja-um (CSYJE) via Nrf2/HO-1 Pathway Activity in Lipopolysaccharide (LPS) Induced RAW 264.7 Macrophages (대식세포에서 Nrf2/HO-1경로를 통한 청심연자음의 항산화효과)

  • Jeon, Seon Hong;Oh, Sol La;Kim, So Jeong;Jeon, Bo Hee;Sung, Jin Young;Kim, Yong Min
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.46 no.3
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    • pp.253-263
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    • 2020
  • Reactive oxygen species (ROS) plays an important role in maintaining homeostasis. However, excessive ROS production damages cellular components such as proteins, lipids, and nucleic acids and promotes skin aging. In this study, we confirmed the antioxidant effect of CSYJE to prevent excessive oxidative stress. First, DPPH and ABTS assays were performed to confirm the antioxidant effect of CSYJE and the radical scavenging activity was confirmed depending on the concentration. As a result of performing the MTT assay to confirm the cell viability, it was confirmed that there was no cytotoxicity at a concentration of 1,000 ㎍/mL. As a result of western blotting to confirm the expression levels of the antioxidant-related proteins nuclear-E2-related factor 2 (Nrf2) and Heme oxygenase-1 (HO-1), it was confirmed that the expression was increased in a concentration-dependent manner. After inducing ROS with lipopolysaccharide (LPS), an intracellular ROS-causing substance, DCF-DA was performed to confirm the inhibitory effect of ROS production, and the inhibition of ROS production was confirmed to concentration-dependent. Real-time RT-PCR was performed to confirm the mRNA expression level of inflammatory cytokines and inflammatory mediator caused by ROS generation, mRNA expression was reduced in a dose dependent manner. Therefore, this study confirmed the antioxidant effect of CSYJE through the Nrf2/HO-1 signaling pathway, which suggests that CSYJE can be used as an antioxidant cosmetic material by inhibiting free radicals.

Beneficial effects of fermented black ginseng and its ginsenoside 20(S)-Rg3 against cisplatin-induced nephrotoxicity in LLC-PK1 cells

  • Han, Myoung-Sik;Han, Im-Ho;Lee, Dahae;An, Jun Min;Kim, Su-Nam;Shin, Myoung-Sook;Yamabe, Noriko;Hwang, Gwi Seo;Yoo, Hye Hyun;Choi, Suk-Jung;Kang, Ki Sung;Jang, Hyuk-Jai
    • Journal of Ginseng Research
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    • v.40 no.2
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    • pp.135-140
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    • 2016
  • Background: Nephrotoxicity is a common side effect of medications. Panax ginseng is one of the best-known herbal medicines, and its individual constituents enhance renal function. Identification of its efficacy and mechanisms of action against drug-induced nephrotoxicity, as well as the specific constituents mediating this effect, have recently emerged as an interesting research area focusing on the kidney protective efficacy of P. ginseng. Methods: The present study investigated the kidney protective effect of fermented black ginseng (FBG) and its active component ginsenoside 20(S)-Rg3 against cisplatin (chemotherapy drug)-induced damage in pig kidney (LLC-PK1) cells. It focused on assessing the role of mitogen-activated protein kinases as important mechanistic elements in kidney protection. Results: The reduced cell viability induced by cisplatin was significantly recovered with FBG extract and ginsenoside 20(S)-Rg3 dose-dependently. The cisplatin-induced elevated protein levels of phosphorylated c-Jun N-terminal kinase (JNK), p53, and cleaved caspase-3 were decreased after cotreatment with FBG extract or ginsenoside 20(S)-Rg3. The elevated percentage of apoptotic LLC-PK1 cells induced by cisplatin treatment was significantly abrogated by cotreatment with FBG and the ginsenoside 20(S)-Rg3. Conclusion: FBG and its major ginsenoside 20(S)-Rg3, ameliorated cisplatin-induced nephrotoxicity in LLC-PK1 cells by blocking the JNKep53ecaspase-3 signaling cascade.

Photoaging protective effects of BIOGF1K, a compound-K-rich fraction prepared from Panax ginseng

  • Hong, Yo Han;Kim, Donghyun;Nam, Gibaeg;Yoo, Sulgi;Han, Sang Yun;Jeong, Seong-Gu;Kim, Eunji;Jeong, Deok;Yoon, Keejung;Kim, Sunggyu;Park, Junseong;Cho, Jae Youl
    • Journal of Ginseng Research
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    • v.42 no.1
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    • pp.81-89
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    • 2018
  • Background: BIOGF1K, a compound-K-rich fraction, has been shown to display anti-inflammatory activity. Although Panax ginseng is widely used for the prevention of photoaging events induced by UVB irradiation, the effect of BIOGF1K on photoaging has not yet been examined. In this study, we investigated the effects of BIOGF1K on UVB-induced photoaging events. Methods: We analyzed the ability of BIOGF1K to prevent UVB-induced apoptosis, enhance matrix metalloproteinase (MMP) expression, upregulate anti-inflammatory activity, reduce sirtuin 1 expression, and melanin production using reverse transcription-polymerase chain reaction, melanin content assay, tyrosinase assay, and flow cytometry. We also evaluated the effects of BIOGF1K on the activator protein-1 signaling pathway, which plays an important role in photoaging, by immunoblot analysis and luciferase reporter gene assays. Results: Treatment of UVB-irradiated NIH3T3 fibroblasts with BIOGF1K prevented UVB-induced cell death, inhibited apoptosis, suppressed morphological changes, reduced melanin secretion, restored the levels of type I procollagen and sirtuin 1, and prevented mRNA upregulation of MMP-1, MMP-2, and cyclo-oxygenase-2; these effects all occurred in a dose-dependent manner. In addition, BIOGF1K markedly reduced activator-protein-1-mediated luciferase activity and decreased the activity of mitogen-activated protein kinases (extracellular response kinase, p38, and C-Jun N-terminal kinase). Conclusion: Our results strongly suggest that BIOGF1K has anti-photoaging activity and that BIOGF1K could be used in anti-aging cosmeceutical preparations.

Analysis of germinating seed stage expressed sequence tags in Oryza sativa L. (벼 발아종자 발현유전자의 발현특성분석)

  • Yoon, Ung-Han;Lee, Gang-Seob;Kim, Chang-Kug;Lee, Jung-Sook;Hahn, Jang-Ho;Yun, Doh-Won;Ji, Hyeon-So;Lee, Tae-Ho;Lee, Jeong-Hwa;Park, Sung-Han;Kim, Gun-Wook;Seo, Mi-Suk;Kim, Yong-Hwan
    • Journal of Plant Biotechnology
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    • v.36 no.3
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    • pp.281-288
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    • 2009
  • Seed germination is the important stage to express many genes for regulation of energy metabolism, starch degradation and cell division from seed dormancy state. For the functional analysis of seed germination mechanisms, we were analyzed the rice cDNA clones (Oryzasativa cultivar Ilpum) obtained from seed imbibition during 48 hours. Total number of 18,101 Expressed Sequence Tags (ESTs) were clustered using SeqMan program. Among them, 8,836 clones were identified as unique clones. We identified the chitinase gene specifically expressed in seed germination and amylase gene involved to starch degradation from the full length cDNA analysis, and several genes were registered to NCBI GeneBank. To analyzed the commonly expressed genes between inmature seed and germinated seed, 25,66 inmature ESTs and 18,101 germinated ESTs were clustered using SeqMan program and identified 2,514 clones as commonly expressed unigene. Among them, alpha-glubulin and alcohol dehydrogenase I were supposed to LEA genes only expressed in the immature and germinated seed stages. For the clustering of orthologous group genes, we further analyzed the 8,836 EST clones from germinating seeds using NCBI clusters of orthologous groups database. Among the clones, 5,076 clones were categorized into information storage and processing, cellular processes and signaling, metabolism and poorly characterized genes, proportioning 783 (14.29%), 1,484 (27%), 1,363 (24.8%) and 1,869 (34%) clones to the previous four categories, respectively.

Inhibition of Transient Receptor Potential Melastain 7 Enhances Apoptosis Induced by TRAIL in PC-3 cells

  • Lin, Chang-Ming;Ma, Ji-Min;Zhang, Li;Hao, Zong-Yao;Zhou, Jun;Zhou, Zhen-Yu;Shi, Hao-Qiang;Zhang, Yi-Fei;Shao, En-Ming;Liang, Chao-Zhao
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.10
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    • pp.4469-4475
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    • 2015
  • Transient receptor potential melastain 7 (TRPM7) is a bifunctional protein with dual structure of both ion channel and protein kinase, participating in a wide variety of diseases including cancer. Recent researches have reported the mechanism of TRPM7 in human cancers. However, the correlation between TRPM7 and prostate cancer (PCa) has not been well studied. The objective of this study was to investigate the potential the role of TRPM7 in the apoptosis of PC-3 cells, which is the key cell of advanced metastatic PCa. In this study, we demonstrated the influence and potential function of TRPM7 on the PC-3 cells apoptosis induced by TNF-related apoptosis inducing-ligand (TRAIL). The study also found a novel up-regulated expression of TRPM7 in PC-3 cells after treating with TRAIL. Suppression of TRPM7 by TRPM7 non-specific inhibitors ($Gd^{3+}$ or 2-aminoethoxy diphenylborate (2-APB) ) not only markedly eliminated TRPM7 expression level, but also increased the apoptosis of TRAIL-treated PC-3 cells, which may be regulated by the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathway accompany with up-regulated expression of cleaved Caspase-3, (TRAIL-receptor 1, death receptors 4) DR4, and (TRAIL-receptor 2, death receptors 5) DR5. Taken together, our findings strongly suggested that TRPM7 was involved in the apoptosis of PC-3 cells induced by TRAIL, indicating that TRPM7 may be applied as a therapeutic target for PCa.

Activation of JNKs is essential for BMP9-induced osteogenic differentiation of mesenchymal stem cells

  • Zhao, Yan-Fang;Xu, Jing;Wang, Wen-Juan;Wang, Jin;He, Juan-Wen;Li, Li;Dong, Qian;Xiao, Yan;Duan, Xing-Lian;Yang, Xue;Liang, Yi-Wen;Song, Tao;Tang, Min;Zhao, Dan;Luo, Jin-Yong
    • BMB Reports
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    • v.46 no.8
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    • pp.422-427
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    • 2013
  • Although BMP9 is highly capable of promoting osteogenic differentiation of mesenchymal stem cell (MSCs), the molecular mechanism involved remains to be fully elucidated. Here, we explore the possible involvement and detail role of JNKs (c-Jun N-terminal kinases) in BMP9-induced osteogenic differentiation of MSCs. It was found that BMP9 stimulated the activation of JNKs in MSCs. BMP9-induced osteogenic differentiation of MSCs was dramatically inhibited by JNKs inhibitor SP600125. Moreover, BMP9-activated Smads signaling was decreased by SP600125 treatment in MSCs. The effects of inhibitor are reproduced with adenoviruses expressing siRNA targeted JNKs. Taken together, our results revealed that JNKs was activated in BMP9-induced osteogenic differentiation of MSCs. What is most noteworthy, however, is that inhibition of JNKs activity resulted in reduction of BMP9-induced osteogenic differentiation of MSCs, implying that activation of JNKs is essential for BMP9 osteoinductive activity.