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  1. Upregulation of heat shock protein 70 and the differential protein expression induced by tumor necrosis factor-alpha enhances migration and inhibits apoptosis of hepatocellular carcinoma cell HepG2.

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    Huang, Bee-Piao; Lin, Chun-Shiang; Wang, Chau-Jong; Kao, Shao-Hsuan

    2017-01-01

    Tumor necrosis factor alpha (TNFα) plays diverse roles in liver damage and hepatocarcinogenesis with its multipotent bioactivity. However, the influence of TNFα on protein expression of hepatocellular carcinoma (HCC) is incompletely understood. Therefore, we aimed to investigate the differential protein expression of HCC in response to TNFα stimulus. We observed that HepG2 cell revealed a higher resistance to TNFα-induced apoptosis as compared to the non-tumorigenic hepatocyte THLE-2. By using a label-free quantitative proteomic analysis, we found that 520 proteins were differentially expressed in the HepG2 cells exposed to TNFα, including 211 up-regulated and 309 down-regulated proteins. We further confirmed several proteins with significant expression change (TNFα/control ratio>2.0 or expressed proteins using Gene ontology and KEGG annotations, and the results implicated that TNFα might regulate ribosome, spliceosome, antigen processing and presentation, and energy metabolism in HepG2 cells. Moreover, we demonstrated that upregulation of heat shock protein 70 (HSP70) was involved in both the promoted migration and the inhibited apoptosis of HepG2 cells in response to TNFα. Collectively, these findings indicate that TNFα alters protein expression such as HSP70, which triggering specific molecular processes and signaling cascades that promote migration and inhibit apoptosis of HepG2 cells.

  2. The Antiapoptosis Effect of Glycyrrhizate on HepG2 Cells Induced by Hydrogen Peroxide

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    Miao Su

    2016-01-01

    Full Text Available This study demonstrated that glycyrrhizate (GAS could protect HEPG2 cells against damage and apoptosis induced by H2O2 (1600 μM, 4 h. Cell viability assay revealed that GAS was noncytotoxity at concentration 125 µg/mL, and GAS (5 μg/mL, 25 μg/mL, and 125 μg/mL protected HepG2 cells against H2O2-induced cytotoxicity. H2O2 induced the HepG2 cells apoptosis, obvious morphologic changes were observed after Hochest 33258 staining, and more apoptotic cells were counted in flow cytometry assay compared to that of the natural group. Pretreatment GAS (5 μg/mL, 25 μg/mL, and 125 μg/mL prior to H2O2 reverses the morphologic changes and reduced the apoptotic cells in HepG2 cells. GAS reduced the release of MDA, increased the activities of superoxide dismutase, and diminished the release of ALT and AST during oxidative stress in HepG2 cells. After Elisa kit detecting, GAS inhibited the caspase activity induced by H2O2, GAS decreased the level of caspase-3 and caspase-9 from mitochondria in dose-dependent manner. Western blot results showed that pretreatment GAS upregulated the expression of Bcl-2 and decreased the expression of Bax. These results reveal that GAS has the cytoprotection in HepG2 cells during ROS exposure by inhibiting the caspase activity in the mitochondria and influencing apoptogenic factors of the expression of Bax and Bcl-2.

  3. Upregulation of heat shock protein 70 and the differential protein expression induced by tumor necrosis factor-alpha enhances migration and inhibits apoptosis of hepatocellular carcinoma cell HepG2

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    Huang, Bee-Piao; Lin, Chun-Shiang; Wang, Chau-Jong; Kao, Shao-Hsuan

    2017-01-01

    Tumor necrosis factor alpha (TNF?) plays diverse roles in liver damage and hepatocarcinogenesis with its multipotent bioactivity. However, the influence of TNF? on protein expression of hepatocellular carcinoma (HCC) is incompletely understood. Therefore, we aimed to investigate the differential protein expression of HCC in response to TNF? stimulus. We observed that HepG2 cell revealed a higher resistance to TNF?-induced apoptosis as compared to the non-tumorigenic hepatocyte THLE-2. By usin...

  4. Recombinant human decorin suppresses liver HepG2 carcinoma cells by p21 upregulation

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    Zhang Y

    2012-08-01

    Full Text Available Yucheng Zhang, Yali Wang,* Zhenwu Du, Qian Wang, Mei Wu, Xiaofeng Wang, Lingling Wang, Linlin Cao, Abdu Selim Hamid, Guizhen Zhang*Central Laboratory, China-Japan Union Hospital, Jilin University, Changchun, People's Republic of China *These authors contributed equally to this workBackground: Decorin is a multifunctional molecule of the extracellular matrix and impedes different kinds of tumor cell growth, but the role and molecular mechanism by which decorin inhibits HepG2 cells is not fully understood. Our objective was to construct recombinant human decorin (pcDNA3.1-DCN and to explore the mechanism by which it inhibits HepG2 cells.Methods: This experiment was divided into three groups, ie, a control group, an empty vector group, and a pcDNA3.1-DCN group. pcDNA3.1-DCN was constructed using recombinant DNA technology, and the vector for pcDNA3.1-DCN and pcDNA3.1 was then transfected into HepG2 cells using Lipofectamine 2000.Results: Compared with cells in the control group and in the empty vector group, growth of cells in the pcDNA3.1-DCN group was significantly suppressed, the ratios of cells in the G0/G1 phases and proportion of early apoptotic cells were significantly increased, and the level of p21WAF1/CIP1 (p21 protein was markedly upregulated (P < 0.05. However, there was no significant difference among the three groups in p53 protein expression (P > 0.05.Conclusion: The pcDNA3.1-DCN vector was successfully constructed and transfected into HepG2 cells, and decorin overexpression suppressed the growth of HepG2 cells by upregulation of p21 via a p53-independent pathway.Keywords: decorin, HepG2, liver cancer, p21WAF1/CIP1, pcDNA3.1

  5. β3-Adrenoceptor activation upregulates apolipoprotein A-I expression in HepG2 cells, which might further promote cholesterol efflux from macrophage foam cells

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    Gao XQ

    2017-03-01

    Full Text Available Xia-qing Gao,1,2 Yan-fang Li,1,2 Zhi-li Jiang1,2 1Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, 2Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, People’s Republic of China Objective: The aim of this study was to explore the effects of β3-adrenoceptor (β3-AR activation on HepG2 cells and its influence on cholesterol efflux from macrophage foam cells. Materials and methods: HepG2 cells were cultured and treated with the β3-AR agonist, BRL37344, and antagonist, SR52390A, and the expression of apolipoprotein (Apo A-I, ApoA-II, ApoB, and β3-AR in the supernatants and cells was determined. The expression of peroxisome proliferator-activated receptor (PPAR γ and PPARα in the HepG2 cells was also assessed. Next, using the RAW264.7 macrophage foam cell model, we also assessed the influence of the HepG2 cell supernatants on lipid efflux. The cholesterol content of the foam cells was also measured, and the cholesterol efflux from the macrophages was examined by determining 3H-labeled cholesterol levels. Expression of ATP-binding cassette transporter (ABC A1 and ABCG1 of the macrophage foam cells was also assessed. Results: β3-AR activation increased ApoA-I expression in both the HepG2 cells and the supernatants; PPARγ expression was upregulated, but PPARα expression was not. Treatment with GW9662 abolished the increased expression of ApoA-I induced by the β3-AR agonist. The HepG2 cell supernatants decreased the lipid accumulation and increased the cholesterol efflux from the macrophage foam cells. ABCA1 expression, but not ABCG1 expression, increased in the macrophage foam cells treated with BRL37344-treated HepG2 cell supernatants. Conclusion: Activation of β3-AR in HepG2 cells upregulates ApoA-I expression, which might further promote cholesterol efflux from macrophage foam cells. PPARγ might be required for the induction of ApoA-I expression. Keywords: β3-adrenoceptor, HepG2 cell

  6. Involvement of mitochondrial pathway in NCTD-induced cytotoxicity in human hepG2 cells

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    Liu Shi-quan

    2010-11-01

    Full Text Available Abstract Background Norcantharidin, the demethylated analog of cantharidin derived from a traditional Chinese medicine, Mylabris, has been used in the treatment of anti-cancer effects. However, the detailed mechanisms underlying this process are generally unclear. The aim of this study was to investigate the mechanism of NCTD-induced apoptosis in HepG2 cells. Methods The cytotoxicity was measured by MTT assay for cellular viability and by flow cytometry. The mitochondrial membrane potential and reactive oxygen species production was evaluated by flow cytometry analysis. The role of caspase activities were assayed using caspase apoptosis detection kit . Western blot analysis was used to evaluate the level of Cyto-C, Bcl-2, Bax, Bid, caspase 3, -9, -8 and PARP expression Results After treatment with NCTD, a decrease in the viability of HepG2 cells and increase in apoptosis were observed. NCTD-induced apoptosis was accompanied by an increase in ROS production, loss of mitochondrial membrane potential and release of cytochrome c(cyto-c from the mitochondria to the cytosol and down-regulation of anti-apoptotic protein Bcl-2 levels with concurrent up-regulation in pro-apoptotic protein Bax levels. However, another pro-apoptotic molecule, Bid, showed no change in such same treatment. NCTD-increased activity of caspase 9,caspase 3 and the subsequent cleavage caspase substrate PARP were also observed. The expression levels of pro-caspase-8 were not changed after NCTD treatment. Conclusion These results indicate that NCTD induced cytotoxicity in HepG2 cells by apoptosis, which is mediated through ROS generation and mitochondrial pathway.

  7. Solanine-induced reactive oxygen species inhibit the growth of human hepatocellular carcinoma HepG2 cells.

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    Meng, Xue-Qin; Zhang, Wei; Zhang, Feng; Yin, Sheng-Yong; Xie, Hai-Yang; Zhou, Lin; Zheng, Shu-Sen

    2016-03-01

    The aim of the present study was to investigate the effect of solanine on promoting human hepatocellular carcinoma HepG2 cells to produce reactive oxygen species (ROS), and the molecular mechanisms leading to tumor cell apoptosis. Solanine was administered to HepG2 cells in vitro. A selection of probes targeting various cellular localizations of ROS were used to detect ROS expression using flow cytometry. The expression levels of apoptosis-associated proteins, including apoptosis signal-regulating kinase 1 (ASK1) and thioredoxin binding protein 2 (TBP-2), and proliferation-associated proteins, including histone deacetylase 1 (HDAC1), were detected using western blotting. The percentage of cells undergoing apoptosis was measured using an Annexin V-fluorescein isothiocyanate/propidium iodide assay, and cell morphology was examined using Wright's stain followed by inverted microscopy analysis. ROS detection probes 2',7'-dichlorofluorescin diacetate and dihydrorhodamine 123 identified that abundant ROS, including hydroxyl radical (OH-) and hydrogen peroxide (H2O2), were produced in the cytoplasm and mitochondria of the solanine-treated HepG2 cells compared with the control cells (Psolanine treatment compared with the control cells (P>0.05). Western blotting results revealed that solanine upregulated the expression levels of ASK1 and TBP-2 and enhanced their kinase activities, whereas solanine decreased the expression level of the proliferation-associated protein, HDAC1. The cell apoptotic rate was significantly increased (Psolanine-treated HepG2 cells compared with the control cells. (Psolanine induces HepG2 cells to produce ROS, mainly OH- and H2O2, in a mitochondria-dependent and -independent manner. In addition, solanine stimulates the expression of ASK1 and TBP-2, and their kinase activities, but inhibits the expression of proliferation-associated proteins, such as HDAC1, thus contributing to HepG2 cell apoptosis.

  8. Patulin-induced oxidative DNA damage and p53 modulation in HepG2 cells.

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    Zhou, Si-min; Jiang, Li-ping; Geng, Cheng-yan; Cao, Jun; Zhong, Lai-fu

    2010-01-01

    Patulin (PAT) is a mycotoxin produced by certain species of Penicillium and Aspergillus. The aim of this study was to assess PAT-induced DNA damage and to clarify the mechanisms, using human hepatoma G2 (HepG2) cells. PAT caused significant increase of DNA migration in single cell gel electrophoresis assay. To elucidate the role of glutathione (GSH), the intracellular GSH level was modulated by pre-treatment with buthionine-(S, R)-sulfoximine, a specific GSH synthesis inhibitor. It was observed that PAT significantly induced DNA damage in GSH-depleted HepG2 cells at lower concentrations. PAT induced the increased levels of reactive oxygen species and depletion of GSH in HepG2 cells using 2,7-dichlorofluorescein diacetate and 0-phthalaldehyde, respectively. PAT significantly increased the levels of 8-hydroxydeoxyguanosine and thiobarbituric acid-reactive substances in HepG2 cells. Also, PAT-induced p53 protein accumulation was observed in HepG2 cells, suggesting that the activation of p53 appeared to have been a downstream response to the PAT-induced DNA damage. These results demonstrate that PAT causes DNA strand breaks in HepG2 cells, probably through oxidative stress. Both GSH, as a main intracellular antioxidant, and p53 protein are responsible for cellular defense against PAT-induced DNA damage. Copyright 2009 Elsevier Ltd. All rights reserved.

  9. Athyrium multidentatum (Doll.) Ching extract induce apoptosis via mitochondrial dysfunction and oxidative stress in HepG2 cells.

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    Qi, Guoyuan; Liu, Zhigang; Fan, Rong; Yin, Ziru; Mi, Yashi; Ren, Bo; Liu, Xuebo

    2017-05-23

    Athyrium multidentatum (Doll.) Ching (AMC), a unique and nutritious potherb widely distributed in china, has been extensively used in traditional Chinese medicine. Previous studies indicated that AMC extract exhibited antioxidant and antitumor properties. However, the chemical composition of AMC and molecular mechanism of AMC toxicity to HepG2 cells have not yet been elucidated. Hence, this study aimed to investigate the chemical compositions and the underlying mechanisms of the antiproliferative and apoptotic effects of AMC on HepG2. HPLC-MS analysis showed that AMC contain five compounds with chlorogenic acid accounting for 43 percent. Also, AMC strongly inhibited the cell growth and induced apoptosis and cell cycle arrest in HepG2 cells by significantly upregulating the protein expressions of Fas, Fas-L, Bax/Bcl-2, cyto-c, cleaved caspase-3, and PARP in a dose-dependent manner, which indicates AMC induces apoptosis in HepG2 cells through both intrinsic and extrinsic pathways. Moreover, AMC provoked the production of ROS, H2O2, and NO, modulating the PI3K/Akt, MAPK, NFκB and Nrf2 pathways and their downstream transcriptional cascades, ultimately evoked oxidative stress and apoptosis in HpeG2 cells. Further in vivo experiments demonstrated that AMC significantly suppressed the tumor growth, suggesting that AMC may be a novel promising agent for hepatocellular carcinoma treatment.

  10. Xanthorrhizol induced DNA fragmentation in HepG2 cells involving Bcl-2 family proteins

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    Tee, Thiam-Tsui, E-mail: thiamtsu@yahoo.com [School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Cheah, Yew-Hoong [School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Bioassay Unit, Herbal Medicine Research Center, Institute for Medical Research, Jalan Pahang, Kuala Lumpur (Malaysia); Meenakshii, Nallappan [Biology Department, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Mohd Sharom, Mohd Yusof; Azimahtol Hawariah, Lope Pihie [School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

    2012-04-20

    Highlights: Black-Right-Pointing-Pointer We isolated xanthorrhizol, a sesquiterpenoid compound from Curcuma xanthorrhiza. Black-Right-Pointing-Pointer Xanthorrhizol induced apoptosis in HepG2 cells as observed using SEM. Black-Right-Pointing-Pointer Apoptosis in xanthorrhizol-treated HepG2 cells involved Bcl-2 family proteins. Black-Right-Pointing-Pointer DNA fragmentation was observed in xanthorrhizol-treated HepG2 cells. Black-Right-Pointing-Pointer DNA fragmentation maybe due to cleavage of PARP and DFF45/ICAD proteins. -- Abstract: Xanthorrhizol is a plant-derived pharmacologically active sesquiterpenoid compound isolated from Curcuma xanthorrhiza. Previously, we have reported that xanthorrhizol inhibited the proliferation of HepG2 human hepatoma cells by inducing apoptotic cell death via caspase activation. Here, we attempt to further elucidate the mode of action of xanthorrhizol. Apoptosis in xanthorrhizol-treated HepG2 cells as observed by scanning electron microscopy was accompanied by truncation of BID; reduction of both anti-apoptotic Bcl-2 and Bcl-X{sub L} expression; cleavage of PARP and DFF45/ICAD proteins and DNA fragmentation. Taken together, these results suggest xanthorrhizol as a potent antiproliferative agent on HepG2 cells by inducing apoptosis via Bcl-2 family members. Hence we proposed that xanthorrhizol could be used as an anti-liver cancer drug for future studies.

  11. VCC-1 over-expression inhibits cisplatin-induced apoptosis in HepG2 cells

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    Zhou, Zhitao; Lu, Xiao; Zhu, Ping [School of Biotechnology, Southern Medical University, Guangzhou 510515 (China); Zhu, Wei [Department of Toxicology, Guangzhou Center for Disease Control and Prevention, Guangzhou 510440 (China); Mu, Xia [Guizhou Provincial People' s Hospital, Guiyang 550004 (China); Qu, Rongmei [School of Biotechnology, Southern Medical University, Guangzhou 510515 (China); Li, Ming, E-mail: limimg2010@yahoo.cn [School of Biotechnology, Southern Medical University, Guangzhou 510515 (China)

    2012-04-06

    Highlights: Black-Right-Pointing-Pointer VCC-1 is hypothesized to be associated with carcinogenesis. Black-Right-Pointing-Pointer Levels of VCC-1 are increased significantly in HCC. Black-Right-Pointing-Pointer Over-expression of VCC-1 could promotes cellular proliferation rate. Black-Right-Pointing-Pointer Over-expression of VCC-1 inhibit the cisplatin-provoked apoptosis in HepG2 cells. Black-Right-Pointing-Pointer VCC-1 plays an important role in control the tumor growth and apoptosis. -- Abstract: Vascular endothelial growth factor-correlated chemokine 1 (VCC-1), a recently described chemokine, is hypothesized to be associated with carcinogenesis. However, the molecular mechanisms by which aberrant VCC-1 expression determines poor outcomes of cancers are unknown. In this study, we found that VCC-1 was highly expressed in hepatocellular carcinoma (HCC) tissue. It was also associated with proliferation of HepG2 cells, and inhibition of cisplatin-induced apoptosis of HepG2 cells. Conversely, down-regulation of VCC-1 in HepG2 cells increased cisplatin-induced apoptosis of HepG2 cells. In summary, these results suggest that VCC-1 is involved in cisplatin-induced apoptosis of HepG2 cells, and also provides some evidence for VCC-1 as a potential cellular target for chemotherapy.

  12. Ellipticine induces apoptosis through p53-dependent pathway in human hepatocellular carcinoma HepG2 cells.

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    Kuo, Yu-Chun; Kuo, Po-Lin; Hsu, Ya-Ling; Cho, Chien-Yu; Lin, Chun-Ching

    2006-04-25

    Ellipticine (5,11-dimethyl-6H-pyrido[4,3-b]carbazole), one of the simplest naturally occurring alkaloids, was isolated from the leaves of the evergreen tree Ochrosia elliptica Labill (Apocynaceae). Here, we reported that ellipticine inhibited the cell growth of human hepatocellular carcinoma cell line HepG2 and provided molecular understanding of this effect. The XTT assay results showed that ellipticine decreased the cell viability of HepG2 cells in a dose- and time-dependent manner, and the IC50 value was 4.1 microM. Furthermore, apoptosis induction by ellipticine in HepG2 cells was verified by the appearance of DNA fragmentation and annexin V-FITC/propidium iodide (PI) staining assay. Ellipticine treatment was found to result in the upregulation of p53, Fas/APO-1 receptor and Fas ligand. Besides, ellipticine also initiated mitochondrial apoptotic pathway through regulation of Bcl-2 family proteins expression, alteration of mitochondrial membrane potential (DeltaPsim), and activation of caspase-9 and caspase-3. Taken together, ellipticine decreased the cell growth and induced apoptosis in HepG2 cell.

  13. Osthole induces G2/M cell cycle arrest and apoptosis in human hepatocellular carcinoma HepG2 cells.

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    Chao, Xu; Zhou, Xiaojun; Zheng, Gang; Dong, Changhu; Zhang, Wei; Song, Xiaomei; Jin, Tianbo

    2014-05-01

    Osthole [7-methoxy-8-(3-methyl-2-butenyl) coumarin] isolated from the fruit of Cnidium monnieri (L.) Cuss, one of the commonly used Chinese medicines listed in the Shennong's Classic of Materia Medica in the Han Dynasty, had remarkable antiproliferative activity against human hepatocellular carcinoma HepG2 cells in culture. This study evaluated the effects of osthole on cell growth, nuclear morphology, cell cycle distribution, and expression of apoptosis-related proteins in HepG2 cells. Cytotoxic activity of osthole was determined by the MTT assay at various concentrations ranging from 0.004 to 1.0 µmol/ml in HepG2 cells. Cell morphology was assessed by Hoechst staining and fluorescence microscopy. Apoptosis and cell-cycle distribution was determined by annexin V staining and flow cytometry. Apoptotic protein levels were assessed by Western blot. Osthole exhibited significant inhibition of the survival of HepG2 cells and the half inhibitory concentration (IC₅₀) values were 0.186, 0.158 and 0.123 µmol/ml at 24, 48 and 72 h, respectively. Cells treated with osthole at concentrations of 0, 0.004, 0.02, 0.1 and 0.5 μmol/ml showed a statistically significant increase in the G2/M fraction accompanied by a decrease in the G0/G1 fraction. The increase of apoptosis induced by osthole was correlated with down-regulation expression of anti-apoptotic Bcl-2 protein and up-regulation expression of pro-apoptotic Bax and p53 proteins. Osthole had significant growth inhibitory activity and the pro-apoptotic effect of osthole is mediated through the activation of caspases and mitochondria in HepG2 cells. Results suggest that osthole has promising therapeutic potential against hepatocellular carcinoma.

  14. Fusaric acid induces mitochondrial stress in human hepatocellular carcinoma (HepG2) cells.

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    Sheik Abdul, Naeem; Nagiah, Savania; Chuturgoon, Anil A

    2016-09-01

    Fusarium spp are common contaminants of maize and produce many mycotoxins, including the fusariotoxin fusaric acid (FA). FA is a niacin related compound, chelator of divalent cations, and mediates toxicity via oxidative stress and possible mitochondrial dysregulation. Sirtuin 3 (SIRT3) is a stress response deacetylase that maintains proper mitochondrial function. We investigated the effect of FA on SIRT3 and oxidative and mitochondrial stress pathways in the hepatocellular carcinoma (HepG2) cell line. We determined FA toxicity (24 h incubation; IC50 = 104 μg/ml) on mitochondrial output, cellular and mitochondrial stress responses, mitochondrial biogenesis and markers of cell death using spectrophotometry, luminometry, qPCR and western blots. FA caused a dose dependent decrease in metabolic activity along with significant depletion of intracellular ATP. FA induced a significant increase in lipid peroxidation, despite up-regulation of the antioxidant transcription factor, Nrf2. FA significantly decreased expression of SIRT3 mRNA with a concomitant decrease in protein expression. Lon protease was also significantly down-regulated. FA induced aberrant mitochondrial biogenesis as evidenced by significantly decreased protein expressions of: PGC-1α, p-CREB, NRF1 and HSP70. Finally, FA activated apoptosis as noted by the significantly increased activity of caspases 3/7 and also induced cellular necrosis. This study provides insight into the molecular mechanisms of FA (a neglected mycotoxin) induced hepatotoxicity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Silver Nanoparticles Induce HePG-2 Cells Apoptosis Through ROS-Mediated Signaling Pathways

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    Zhu, Bing; Li, Yinghua; Lin, Zhengfang; Zhao, Mingqi; Xu, Tiantian; Wang, Changbing; Deng, Ning

    2016-04-01

    Recently, silver nanoparticles (AgNPs) have been shown to provide a novel approach to overcome tumors, especially those of hepatocarcinoma. However, the anticancer mechanism of silver nanoparticles is unclear. Thus, the purpose of this study was to estimate the effect of AgNPs on proliferation and activation of ROS-mediated signaling pathway on human hepatocellular carcinoma HePG-2 cells. A simple chemical method for preparing AgNPs with superior anticancer activity has been showed in this study. AgNPs were detected by transmission electronic microscopy (TEM) and energy dispersive X-ray (EDX). The size distribution and zeta potential of silver nanoparticles were detected by Zetasizer Nano. The average size of AgNPs (2 nm) observably increased the cellular uptake by endocytosis. AgNPs markedly inhibited the proliferation of HePG-2 cells through induction of apoptosis with caspase-3 activation and PARP cleavage. AgNPs with dose-dependent manner significantly increased the apoptotic cell population (sub-G1). Furthermore, AgNP-induced apoptosis was found dependent on the overproduction of reactive oxygen species (ROS) and affecting of MAPKs and AKT signaling and DNA damage-mediated p53 phosphorylation to advance HePG-2 cells apoptosis. Therefore, our results show that the mechanism of ROS-mediated signaling pathways may provide useful information in AgNP-induced HePG-2 cell apoptosis.

  16. Metformin, but not sitagliptin, enhances WP 631-induced apoptotic HepG2 cell death.

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    Sliwinska, Agnieszka; Rogalska, Aneta; Marczak, Agnieszka; Kasznicki, Jacek; Drzewoski, Jozef

    2015-08-01

    Metformin and sitagliptin are hypoglycemic drugs with potential use in cancer treatment. Evidence indicates that metformin may inhibit the proliferation and growth of various types of cancer cells. Data regarding the relationship between sitagliptin and cancer cells is limited. Therapy based on anthracycline derivatives, mainly doxorubicin, is commonly used in the treatment of resistant liver cancers. WP 631 is a new structural analogue of doxorubicin that exerts an anticancer action by the induction of apoptosis. The aim of this study was to compare the effect of metformin and sitagliptin on WP 631-induced apoptotic cell death in a human hepatocarcinoma cell line (HepG2). HepG2 cancer cells are known to be resistant to chemotherapeutic cytotoxic agents. Both MTT assay and flow cytometry analysis showed that WP 631 reduced the growth of HepG2 cells by apoptosis induction, accompanied by elevated NF-κB and p53 levels. Metformin enhanced the pro-apoptotic effect of WP 631, increasing the NF-κB level but not the p53 level. Sitagliptin did not affect the action of WP 631 in HepG2 cancer cells, however, it increased the p53 level. To conclude, our results suggest that metformin significantly enhances the efficacy of anthracycline derivative, although this effect is not observed in the case of sitagliptin. Therefore, metformin seems to be a good candidate for combined therapy of resistant liver cancer with anthracycline derivatives. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Up-Regulation of CYP2C19 Expression by BuChang NaoXinTong via PXR Activation in HepG2 Cells.

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    Hong Sun

    Full Text Available Cytochrome P450 2C19 (CYP2C19 is an important drug-metabolizing enzyme (DME, which is responsible for the biotransformation of several kinds of drugs such as proton pump inhibitors, platelet aggregation inhibitors and antidepressants. Previous studies showed that Buchang NaoXinTong capsules (NXT increased the CYP2C19 metabolic activity in vitro and enhanced the antiplatelet effect of clopidogrel in vivo. However, the underlying molecular mechanism remained unclear. In the present study, we examined whether Pregnane X receptor (PXR plays a role in NXT-mediated regulation of CYP2C19 expression.We applied luciferase assays, real-time quantitative PCR (qPCR, Western blotting and cell-based analysis of metabolic activity experiments to investigate the NXT regulatory effects on the CYP2C19 promoter activity, the mRNA/ protein expression and the metabolic activity.Our results demonstrated that NXT significantly increased the CYP2C19 promoter activity when co-transfected with PXR in HepG2 cells. Mutations in PXR responsive element abolished the NXT inductive effects on the CYP2C19 promoter transcription. Additionally, NXT incubation (150 and 250μg/mL also markedly up-regulated endogenous CYP2C19 mRNA and protein levels in PXR-transfected HepG2 cells. Correspondingly, NXT leaded to a significant enhancement of the CYP2C19 catalytic activity in PXR-transfected HepG2 cells.In summary, this is the first study to suggest that NXT could induce CYP2C19 expression via PXR activation.

  18. Hepatitis B virus induces G1 phase arrest by regulating cell cycle genes in HepG2.2.15 cells

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    Zhang Chong

    2011-05-01

    Full Text Available Abstract Background To investigate the effect of HBV on the proliferative ability of host cells and explore the potential mechanism. Methods MTT, colony formation assay and tumourigenicity in nude mice were performed to investigate the effect of HBV on the proliferative capability of host cells. In order to explore the potential mechanism, cell cycle and apoptosis were analysed. The cell cycle genes controlling the G1/S phase transition were detected by immunohistochemistry, westernblot and RT-PCR. Results HepG2.2.15 cells showed decreased proliferation ability compared to HepG2 cells. G1 phase arrest was the main cause but was not associated with apoptosis. p53, p21 and total retinoblastoma (Rb were determined to be up-regulated, whereas cyclinE was down-regulated at both the protein and mRNA levels in HepG2.2.15 cells. The phosphorylated Rb in HepG2.2.15 cells was decreased. Conclusions Our results suggested that HBV inhibited the capability of proliferation of HepG2.2.15 cells by regulating cell cycle genes expression and inducing G1 arrest.

  19. Role of salt inducible kinase 1 in high glucose-induced lipid accumulation in HepG2 cells and metformin intervention.

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    Zhang, Yue; Takemori, Hiroshi; Wang, Chang; Fu, JiaHui; Xu, MingWang; Xiong, Liang; Li, NingXu; Wen, XiuYing

    2017-03-15

    To investigate the roles of salt inducible kinase (SIK1) in high glucose-induced triglyceride accumulation in human hepatoma HepG2 cells as well as in the molecular mechanism by which metformin, a drug to treat diabetes, suppresses high glucose-induced lipogenesis. A cell model for high glucose-induced hepatic steatosis was prepared by exposing HepG2 cells to high glucose (25mmol) in the absence or presence of metformin (0.5mmol). Intracellular triglycerides were visualized by Oil Red O and measured using a triglyceride assay kit. Cell viability was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. SIK1 overexpression in HepG2 cells was achieved by transient transfection, and the mRNA and protein levels of SIK1 and lipogenic factors were measured using a reverse transcription-polymerase chain reaction and western blotting, respectively. Lipid accumulation in HepG2 cells was obvious after treatment with high glucose for 24h. In response to high glucose, SIK1 expression was negatively correlated with that of lipogenic factors and lipid accumulation in HepG2 cells. We observed that overexpression of SIK1, or treatment with metformin, suppressed lipogenesis, even in high glucose conditions. Furthermore, treatment with metformin upregulated SIK1 mRNA and protein levels, as well as the active form of SIK1. SIK1 plays a vital role in high glucose-induced lipid accumulation, and metformin suppresses lipogenesis via the induction and activation of SIK1. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Hesperidin from Citrus seed induces human hepatocellular carcinoma HepG2 cell apoptosis via both mitochondrial and death receptor pathways.

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    Banjerdpongchai, Ratana; Wudtiwai, Benjawan; Khaw-On, Patompong; Rachakhom, Wasitta; Duangnil, Natthachai; Kongtawelert, Prachya

    2016-01-01

    Citrus seeds are full of phenolic compounds, such as flavonoids. The aims of this study were to identify the types of flavonoids in Citrus seed extracts, the cytotoxic effect, mode of cell death, and signaling pathway in human hepatic cancer HepG2 cells. The flavonoids contain anticancer, free radical scavenging, and antioxidant activities. Neohesperidin, hesperidin, and naringin, active flavanone glycosides, were identified in Citrus seed extract. The cytotoxic effect of three compounds was in a dose-dependent manner, and IC50 levels were determined. The sensitivity of human HepG2 cells was as follows: hesperidin > naringin > neohesperidin > naringenin. Hesperidin induced HepG2 cells to undergo apoptosis in a dose-dependent manner as evidenced by the externalization of phosphatidylserine and determined by annexin V-fluorescein isothiocyanate and propidium iodide staining using flow cytometry. Hesperidin did not induce the generation of reactive oxygen species, which was determined by using 2',7'-dichlorohydrofluorescein diacetate and flow cytometry method. The number of hesperidin-treated HepG2 cells with the loss of mitochondrial transmembrane potential increased concentration dependently, using 3,3'-dihexyloxacarbocyanine iodide employing flow cytometry. Caspase-9, -8, and -3 activities were activated and increased in hesperidin-treated HepG2 cells. Bcl-xL protein was downregulated whereas Bax, Bak, and tBid protein levels were upregulated after treatment with hesperidin in a dose-dependent manner. In conclusion, the bioflavanone from Citrus seeds, hesperidin, induced human HepG2 cell apoptosis via mitochondrial pathway and death receptor pathway. Citrus seed flavonoids are beneficial and can be developed as anticancer drug or food supplement, which still needs further in vivo investigation in animals and human beings.

  1. Realgar transforming solution displays anticancer potential against human hepatocellular carcinoma HepG2 cells by inducing ROS.

    Science.gov (United States)

    Song, Peng; Chen, Peng; Wang, Dong; Wu, Zhengrong; Gao, Qiyu; Wang, Aixia; Zhu, Ruilan; Wang, Yajun; Wang, Xin; Zhao, Longhe; Duan, Ziyun; Zhu, Shuqian; Cui, Peng; Li, Yang; Li, Hongyu

    2017-02-01

    Realgar (As4S4), as a mineral drug containing arsenic compound, has been employed in clinical therapy of cancer for its good therapeutic reputation in Chinese traditional medicine. However, large dose of realgar and long period of treatment are necessary for achieving the effective blood medicine concentration due to its low bioavailability resulted from poor solubility. In this study, we obtained realgar transforming solution (RTS) using intrinsic biotransformation in microorganism, and investigated underlying mechanisms of RTS for HepG2 cells. Our results demonstrated that an effective biotransformation of realgar method by A. ferrooxidans was established, in which realgar was biologically converted into an aqueous solution, and RTS had a strong activity inducing apoptosis and interrupting G2/M progression in HepG2 cells via upregulation of cellular ROS. Importantly, RTS inhibited the cellular antioxidant defense system leading to abundant ROS accumulation, and activated cell cycle arrest and mitochondrial pathway of apoptosis mediated by activating p53 due to cellular uncontrolled ROS. Collectively, our findings suggest that RTS is a potential candidate for therapy of human hepatocellular carcinoma.

  2. 20(S)-Protopanaxadiol induces apoptosis in human hepatoblastoma HepG2 cells by downregulating the protein kinase B signaling pathway.

    Science.gov (United States)

    Lu, Zeyuan; Xu, Huali; Yu, Xiaofeng; Wang, Yuchen; Huang, Long; Jin, Xin; Sui, Dayun

    2018-02-01

    Hepatoblastoma is the most common primary liver tumor for children aged S)-Protopanaxadiol (PPD) is a ginsenoside extracted from Pananx quinquefolium L ., which inhibits tumor growth in several cancer cell lines. The purpose of the present study was to assess the anticancer activities of 20(S)-PPD in human hepatoblastoma HepG2 cells. The cytotoxicity of 20(S)-PPD on HepG2 cells was evaluated using an MTT assay. Apoptosis was detected using DAPI staining and flow cytometry. The expression of apoptosis-associated proteins was identified by western blotting. The results demonstrated that 20(S)-PPD inhibited the viability of HepG2 cell in a dose and time-dependent manner. The IC 50 values were 81.35, 73.5, 48.79 µM at 24, 48 and 72 h, respectively. Topical morphological changes of apoptotic body formation following 20(S)-PPD treatment were detected by DAPI staining. The percentage of Annexin V-fluoroscein isothyiocyanate positive cells were 3.73, 17.61, 23.44 and 65.43% in HepG2 cells treated with 0, 40, 50 and 60 µM of 20(S)-PPD, respectively. Furthermore, 20(S)-PPD upregulated the expression of Bax and downregulated the expression of Bcl-2 and also activated caspases-3 and -9, and Poly [ADP-ribose] polymerase cleavage. In addition, 20(S)-PPD inhibited the phosphorylation of protein kinase B (Akt; Ser473). The results indicate that 20(S)-PPD inhibits the viability of HepG2 cells and induces apoptosis in HepG2 cells by inhibiting the phosphoinositide-3-kinase/Akt pathway.

  3. Campomanesia adamantium (Myrtaceae fruits protect HEPG2 cells against carbon tetrachloride-induced toxicity

    Directory of Open Access Journals (Sweden)

    Thaís de Oliveira Fernandes

    2015-01-01

    Full Text Available Campomanesia adamantium (Myrtaceae is an antioxidant compounds-rich Brazilian fruit popularly known as gabiroba. In view of this, it was evaluated the hepatoprotective effects of pulp (GPE or peel/seed (GPSE hydroalcoholic extracts of gabiroba on injured liver-derived HepG2 cells by CCl4 (4 mM. The results showed the presence of total phenolic in GPSE was (60% higher when compared to GPE, associated with interesting antioxidant activity using DPPH·− assay. Additionally, HPLC chromatograms and thin layer chromatography of GPE and GPSE showed the presence of flavonoids. Pretreatment of HepG2 cells with GPE or GPSE (both at 800–1000 μg/mL significantly (p < 0.0001 protected against cytotoxicity induced by CCl4. Additionally, the cells treated with both extracts (both at 1000 μg/mL showed normal morphology (general and nuclear contrasting with apoptotic characteristics in the cells only exposed to CCl4. In these experiments, GPSE also was more effective than GPE. In addition, CCl4 induced a marked increase in AST (p < 0.05 and ALT (p < 0.0001 levels, while GPE or GPSE significantly (p < 0.0001 reduced these levels, reaching values found in the control group. In conclusion, the results suggest that gabiroba fruits exert hepatoprotective effects on HepG2 cells against the CCl4-induced toxicity, probably, at least in part, associated with the presence of antioxidant compounds, especially flavonoids.

  4. TRAF1 knockdown alleviates palmitate-induced insulin resistance in HepG2 cells through NF-κB pathway

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    Zhang, Wanlu [Department of Pathogen Biology, Medical College, Nantong University, 19 Qixiu Road, Nantong 226001, Jiangsu Province (China); Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Nantong University, 19 Qixiu Road, Nantong 226001, Jiangsu Province (China); Tang, Zhuqi; Zhu, Xiaohui [Department of Endocrinology, Affiliated Hospital of Nantong University, 20 Xisi Road, Nantong 226001, Jiangsu Province (China); Xia, Nana; Zhao, Yun; Wang, Suxin [Department of Pathogen Biology, Medical College, Nantong University, 19 Qixiu Road, Nantong 226001, Jiangsu Province (China); Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Nantong University, 19 Qixiu Road, Nantong 226001, Jiangsu Province (China); Cui, Shiwei, E-mail: neifenmicui@163.com [Department of Endocrinology, Affiliated Hospital of Nantong University, 20 Xisi Road, Nantong 226001, Jiangsu Province (China); Wang, Cuifang, E-mail: binghuodinghuo@163.com [Department of Endocrinology, Affiliated Hospital of Nantong University, 20 Xisi Road, Nantong 226001, Jiangsu Province (China)

    2015-11-20

    High-fat diet (HFD) and inflammation are key contributors to insulin resistance (IR) and Type 2 diabetes mellitus (T2DM). With HFD, plasma free fatty acids (FFAs) can activate the nuclear factor-κB (NF-κB) in target tissues, then initiate negative crosstalk between FFAs and insulin signaling. However, the molecular link between IR and inflammation remains to be identified. We here reported that tumor necrosis factor receptor-associated factor 1 (TRAF1), an adapter in signal transduction, was involved in the onset of IR in hepatocytes. TRAF1 was significantly up-regulated in insulin-resistant liver tissues and palmitate (PA)-treated HepG2 cells. In addition, we showed that depletion of TRAF1 led to inhibition of the activity of NF-κB. Given the fact that the activation of NF-κB played a facilitating role in IR, the phosphorylation of Akt and GSK3β was also analyzed. We found that depletion of TRAF1 markedly reversed PA-induced attenuation of the phosphorylation of Akt and GSK3β in the cells. The accumulation of lipid droplets in hepatocyte and expression of two key gluconeogenic enzymes, PEPCK and G6Pase, were also determined and found to display a similar tendency with the phosphorylation of Akt and GSK3β. Glucose uptake assay indicated that knocking down TRAF1 blocked the effect of PA on the suppression of glucose uptake. These data implicated that TRAF1 knockdown might alleviate PA-induced IR in HepG2 cells through NF-κB pathway. - Highlights: • TRAF1 accelerated PA-induced IR in HepG2 cells mediated through NF-κB signaling. • Knockdown of TRAF1 alleviated PA-induced IR in HepG2 cells. • Knockdown of TRAF1 alleviated PA-induced lipid accumulation in HepG2 cells. • Knockdown of TRAF1 reversed PA-induced suppression of glucose uptake in HepG2 cells. • Knockdown of TRAF1 reversed PA-induced gluconeogenesis in HepG2 cells.

  5. N-acetylcysteine does not protect HepG2 cells against acetaminophen-induced apoptosis.

    Science.gov (United States)

    Manov, Irena; Hirsh, Mark; Iancu, Theodore C

    2004-05-01

    Acetaminophen in large doses is well-known as hepatotoxic, and early therapy with N-acetylcysteine is frequently life-saving. However, in later stages of acetaminophen poisoning, treatment with N-acetylcysteine is not always effective. Although some of the pathways of acetaminophen toxicity and the effect of N-acetylcysteine have been elucidated, in depth information on this process is still lacking. Hepatoma-derived HepG2 cultured cells were exposed to acetaminophen (5 and 10 mM), with or without N-acetylcysteine (5 mM), for 24 and 48 hr. For the assessment of oxidative damage, apoptosis and necrosis, we followed redox status, glutathione content, nuclear fragmentation, phosphatidylserine externalization and ultrastructural changes. Variations in Ca2+ level and number of mitochondrial dense granules were also studied. Acetaminophen treatment of HepG2 cells caused oxidative damage and apoptosis. Significant decrease of cellular redox potential and glutathione content were time- and concentration-dependent. The protective effect of N-acetylcysteine was expressed by an increase of intracellular glutathione and of the level of metabolic reduction of the redox indicator Alamar Blue. The apoptogenic effect of acetaminophen was assessed by flow cytometry of annexin V binding, nuclear hypodiploidity, intracellular Ca2+, as well as by ultrastructural examination. Beyond 24 hr of acetaminophen exposure, necrosis was also noticed. We conclude that acetaminophen-induced oxidative damage in HepG2 cultured cells can be prevented by exposure to N-acetylcysteine. However, apoptosis, either early or late, here demonstrated, is not avoided by exposure to N-acetylcysteine. N-Acetylcysteine did not prevent acetaminophen-induced plasma membrane asymmetry, nuclear damage, alterations of Ca2+ homeostasis and ultrastructural changes.

  6. Mechanisms of tolvaptan-induced toxicity in HepG2 cells.

    Science.gov (United States)

    Wu, Yuanfeng; Beland, Frederick A; Chen, Si; Liu, Fang; Guo, Lei; Fang, Jia-Long

    2015-06-15

    Tolvaptan, a vasopressin receptor 2 antagonist used to treat hyponatremia, has recently been reported to be associated with an increased risk of liver injury. In this study, we explored the underlying mechanisms of hepatotoxicity of tolvaptan using human HepG2 cells. Tolvaptan inhibited cell growth and caused cell death in a concentration- and time-dependent manner. Tolvaptan treatment led to delayed cell cycle progression, accompanied by decreased levels of several cyclins and cyclin-dependent kinases. Tolvaptan was found to cause DNA damage, as assessed by alkaline comet assays; this was confirmed by increased levels of 8-oxoguanine and phosphorylation of histone H2AX. Exposure of HepG2 cells to tolvaptan enhanced cytochrome C release and triggered apoptosis by modulating Bcl-2 family members. The activation of p38 contributed to tolvaptan-mediated apoptosis via down-regulation of Bcl-2. Proteasome inhibition altered tolvaptan-induced cell cycle deregulation and enhanced tolvaptan-induced apoptosis and cytotoxicity. Moreover, tolvaptan treatment induced autophagy. Inhibition of autophagy by knocking-down an autophagy-related gene increased tolvaptan-induced apoptosis and cytotoxicity. Taken together, our findings suggest that the cytotoxicity of tolvaptan results from delayed cell cycle progression, the induction of DNA damage, and the execution of apoptosis. In addition, a number of signaling pathways were perturbed by tolvaptan and played an important role in its cytotoxicity. Published by Elsevier Inc.

  7. 6-gingerol prevents patulin-induced genotoxicity in HepG2 cells.

    Science.gov (United States)

    Yang, Guang; Zhong, Laifu; Jiang, Liping; Geng, Chengyan; Cao, Jun; Sun, Xiance; Liu, Xiaofang; Chen, Min; Ma, Yufang

    2011-10-01

    Patulin (PAT) is a mycotoxin produced by several Penicillium, Aspergillus and Byssochlamys species. Since PAT is a potent genotoxic compound, and PAT contamination is common in fruits and fruit products, the search for newer, better agents for protection against genotoxicity of PAT is required. In this study, the chemoprotective effect of 6-gingerol against PAT-induced genotoxicity in HepG2 cells was investigated. The comet assay and micronucleus test (MNT) were used to monitor genotoxic effects. To further elucidate the underlying mechanisms, the intracellular generation of reactive oxygen species (ROS) and level of reduced glutathione (GSH) were tested. In addition, the level of oxidative DNA damage was evaluated by immunocytochemical analysis of 8-hydroxydeoxyguanosine (8-OHdG). The results showed that 6-gingerol significantly reduced the DNA strand breaks and micronuclei formation caused by PAT. Moreover, 6-gingerol effectively suppressed PAT-induced intracellular ROS formation and 8-OHdG level. The GSH depletion induced by PAT in HepG2 cells was also attenuated by 6-gingerol pretreatment. These findings suggest that 6-gingerol has a strong protective ability against the genotoxicity caused by PAT, and the antioxidant activity of 6-gingerol may play an important part in attenuating the genotoxicity of PAT. Copyright © 2011 John Wiley & Sons, Ltd.

  8. Effects of the cyclophilin-type peptidylprolyl cis-trans isomerase from Pyropia yezoensis against hydrogen peroxide-induced oxidative stress in HepG2 cells.

    Science.gov (United States)

    Kim, Eun-Young; Choi, Youn Hee; Choi, Chang Geun; Nam, Taek-Jeong

    2017-06-01

    The present study aimed to describe the expression and purification of cyclophilin-type peptidylprolyl cis-trans isomerase (PPI) from the red alga Pyropia yezoensis. The antioxidant activity of the purified protein was also demonstrated, based on its ability to act against oxidative stress in HepG2 human hepatocellular carcinoma cells. HepG2 cells that were treated with recombinant PPI protein exhibited a reduction in the formation of hydrogen peroxide (H2O2)‑mediated reactive oxygen species (ROS). In HepG2 cells, treatment of recombinant PPI protein expression diminished H2O2‑mediated oxidative stress and restored both the expression and the activity of certain antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and thioredoxin reductase (TRR). CAT, SOD and TRR activities were upregulated by treatment with the purified protein. CAT mRNA expression was significantly increased in HepG2 cells treated with recombinant PPI protein. These enzymes are the first line of antioxidant defense against ROS generated in times of oxidative stress. Accordingly, data from the present study indicate that the recombinant PPI protein is able to regulate the expression of antioxidant enzymes. Recombinant PPI has antioxidant properties that prevent oxidative stress‑induced toxicity, enhance cell viability, decrease ROS production and inhibit oxidative damage and mitochondrial dysfunction in HepG2 cells. Therefore, the present study hypothesizes that the recombinant PPI protein has the potential to protect the liver against oxidative stress‑induced cell damage and should be considered as an antioxidant.

  9. Investigation of quercetin-induced HepG2 cell apoptosis-associated cellular biophysical alterations by atomic force microscopy.

    Science.gov (United States)

    Pi, Jiang; Li, Baole; Tu, Lvying; Zhu, Haiyan; Jin, Hua; Yang, Fen; Bai, Haihua; Cai, Huaihong; Cai, Jiye

    2016-01-01

    Quercetin, a wildly distributed bioflavonoid, has been proved to possess excellent antitumor activity on hepatocellular carcinoma (HCC). In the present study, the biophysical properties of HepG2 cells were qualitatively and quantitatively determined using high resolution atomic force microscopy (AFM) to understand the anticancer effects of quercetin on HCC cells at nanoscale. The results showed that quercetin could induce severe apoptosis in HepG2 cells through arrest of cell cycle and disruption of mitochondria membrane potential. Additionally, the nuclei and F-actin structures of HepG2 cells were destroyed by quercetin treatment as well. AFM morphological data showed some typical apoptotic characterization of HepG2 cells with increased particle size and roughness in the ultrastructure of cell surface upon quercetin treatment. As an important biophysical property of cells, the membrane stiffness of HepG2 cells was further quantified by AFM force measurements, which indicated that HepG2 cells became much stiffer after quercetin treatment. These results collectively suggest that quercetin can be served as a potential therapeutic agent for HCC, which not only extends our understanding of the anticancer effects of quercetin against HCC cells into nanoscale, but also highlights the applications of AFM for the investigation of anticancer drugs. © Wiley Periodicals, Inc.

  10. Signaling dynamics of palmitate-induced ER stress responses mediated by ATF4 in HepG2 cells

    Directory of Open Access Journals (Sweden)

    Cho Hyunju

    2013-01-01

    Full Text Available Abstract Background Palmitic acid, the most common saturated free fatty acid, has been implicated in ER (endoplasmic reticulum stress-mediated apoptosis. This lipoapotosis is dependent, in part, on the upregulation of the activating transcription factor-4 (ATF4. To better understand the mechanisms by which palmitate upregulates the expression level of ATF4, we integrated literature information on palmitate-induced ER stress signaling into a discrete dynamic model. The model provides an in silico framework that enables simulations and predictions. The model predictions were confirmed through further experiments in human hepatocellular carcinoma (HepG2 cells and the results were used to update the model and our current understanding of the signaling induced by palmitate. Results The three key things from the in silico simulation and experimental results are: 1 palmitate induces different signaling pathways (PKR (double-stranded RNA-activated protein kinase, PERK (PKR-like ER kinase, PKA (cyclic AMP (cAMP-dependent protein kinase A in a time dependent-manner, 2 both ATF4 and CREB1 (cAMP-responsive element-binding protein 1 interact with the Atf4 promoter to contribute to a prolonged accumulation of ATF4, and 3 CREB1 is involved in ER-stress induced apoptosis upon palmitate treatment, by regulating ATF4 expression and possibly Ca2+ dependent-CaM (calmodulin signaling pathway. Conclusion The in silico model helped to delineate the essential signaling pathways in palmitate-mediated apoptosis.

  11. Protective effects of allicin on 1,3-DCP-induced lipid metabolism disorder in HepG2 cells.

    Science.gov (United States)

    Lu, Jing; Cheng, Bijun; Fang, Baochen; Meng, Zhuoqun; Zheng, Yiying; Tian, Xiaochen; Guan, Shuang

    2017-12-01

    Allicin (2-propene-1-sulfinothioic acid S-2-propenyl ester), with quite a good range of hepatoprotective and antineoplastic properties, is a functional substance from garlic (Allium sativum L.) The purpose of this study was to provide evidence that allicin could protect 1,3-DCP-induced lipid metabolism disorder in HepG2 cells. Allicin reduced the accumulation of triglycerides (TG) and total cholesterol (TC) in 1,3-DCP-induced HepG2 cells. Allicin significantly increased the phosphorylation of AMP-activated protein kinase (AMPK) and down-regulated the levels of sterol regulatory element binding protein-1 (SREBP-1) and sterol regulatory element binding protein-2 (SREBP-2) in 1,3-DCP-induced HepG2 cells. Additionally, allicin had obvious recovery influence on the phosphorylation level of PKA and CREB in 1,3-DCP-induced HepG2 cells. These observations indicated that allicin alleviated lipid metabolism disorder induced by 1,3-DCP in HepG2 cells by regulating AMPK-SREBPs and PKA-CREB signaling pathways. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  12. Saururus chinensis Baill induces apoptosis through endoplasmic reticulum stress in HepG2 hepatocellular carcinoma cells.

    Science.gov (United States)

    Lee, Ah Young; Han, Young-Ah; Kim, Ji-Eun; Hong, Seong-Ho; Park, Eun-Jung; Cho, Myung-Haing

    2015-09-01

    In this study, we examined the mechanism underlying the effect of Saururus chinensis Baill (saururaceae) on hepatocellular carcinoma HepG2 cells. HepG2 cells and Chang cells were exposed to various concentrations of S. chinensis Baill extract (SC-E) for 24 h. SC-E affected more significantly HepG2 cells than Chang cells in terms of cell viability and ATP production. Therefore, current study examined detailed mechanism how SC-E affected HepG2 cell survival. We found that SC-E (75 and 150 μg/ml) induced apoptosis via oxidative stress. SC-E also caused CCAAT-enhancer-binding protein homologous protein (CHOP) activation by dissociating the binding immunoglobulin protein (BiP) from inositol-requiring 1α (IRE1α) in the endoplasmic reticulum (ER) and induced Bax, cytochrome c release to cytosol, caspase-3 activation, and poly ADP ribose polymerase (PARP) cleavage, resulting in HepG2 cell apoptosis. Furthermore, SC-E caused ER Ca(2+) leakage into the cytosol; ER dilation and mitochondrial membrane damage were observed in transmission electron microscopy (TEM). Taken together, our results demonstrated that SC-E induced cancer cell apoptosis specifically through ER stress. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Mitochondrial Dysfunction and Ca(2+) Overload Contributes to Hesperidin Induced Paraptosis in Hepatoblastoma Cells, HepG2.

    Science.gov (United States)

    Yumnam, Silvia; Hong, Gyeong Eun; Raha, Suchismita; Saralamma, Venu Venkatarame Gowda; Lee, Ho Jeong; Lee, Won-Sup; Kim, Eun-Hee; Kim, Gon Sup

    2016-06-01

    Paraptosis is a programmed cell death which is morphologically and biochemically different from apoptosis. In this study, we have investigated the role of Ca(2+) in hesperidin-induced paraptotic cell death in HepG2 cells. Increase in mitochondrial Ca(2+) level was observed in hesperidin treated HepG2 cells but not in normal liver cancer cells. Inhibition of inositol-1,4,5-triphosphate receptor (IP3 R) and ryanodine receptor also block the mitochondrial Ca(2+) accumulation suggesting that the release of Ca(2+) from the endoplasmic reticulum (ER) may probably lead to the increase in mitochondrial Ca(2+) level. Pretreatment with ruthenium red (RuRed), a Ca(2+) uniporter inhibitor inhibited the hesperidin-induced mitochondrial Ca(2+) overload, swelling of mitochondria, and cell death in HepG2 cells. It has also been demonstrated that mitochondrial Ca(2+) influxes act upstream of ROS and mitochondrial superoxide production. The increased ROS production further leads to mitochondrial membrane loss in hesperidin treated HepG2 cells. Taken together our results show that IP3 R and ryanodine receptor mediated release of Ca(2+) from the ER and its subsequent influx through the uniporter into mitochondria contributes to hesperidin-induced paraptosis in HepG2 cells. © 2015 Wiley Periodicals, Inc.

  14. Protective Effect of Wild Ginseng Extract against y-BHP-induced Oxidative Damage in HepG2 Cells Using DNA Chip

    Directory of Open Access Journals (Sweden)

    Hyung-Seok Kim

    2007-02-01

    Full Text Available Objectives : This study was carried out to examine protective effect of wild ginseng extract on HepG2 human hepatoma cell line against tert-Butyl hydroperoxide (t-BHP-induced oxidative damage. Methods : To evaluate protective effect of wild ginseng extract against t-BHP induced cytotoxicity, LDH level and activity of glutathione peroxidase and reductase were measured. Gene expression was also measured using DNA microarray. Results : Wild ginseng extract showed a significant protective effect against t-BHP-induced cytotoxicity in HepG2 cell line. It is not, however, related with the activities of glutathione peroxidase and glutathione reductase. Analysis of gene expression using DNA chip, demonstrated that 28 genes were up-regulated in t-BHP only group. Five genes - selenoprotein P, glutathione peroxidase 3, sirtuin 2, peroxiredoxin 2, serfiredoxin 1 homolog - may be related with the protective effect of wild ginseng extract. Conclusions : Based on the results, a protective effect of wild ginseng extract against t-BHP-induced oxidative damage in HepG2 cell line is not associated with the activities of glutathione peroxidase and glutathione reductase, but with the expression of selenoprotein P, glutathione peroxidase 3, sirtuin 2, peroxiredoxin 2, and serfiredoxin 1 homolog.

  15. Hesperidin Induces Paraptosis Like Cell Death in Hepatoblatoma, HepG2 Cells: Involvement of ERK1/2 MAPK

    Science.gov (United States)

    Yumnam, Silvia; Park, Hyeon Soo; Kim, Mun Ki; Nagappan, Arulkumar; Hong, Gyeong Eun; Lee, Ho Jeong; Lee, Won Sup; Kim, Eun Hee; Cho, Jae Hyeon; Shin, Sung Chul; Kim, Gon Sup

    2014-01-01

    Hesperidin, a natural flavonoid abundantly present in Citrus is known for its anti-cancer, anti-oxidant and anti-inflammatory properties. In this study we examined the effect of hesperidin on HepG2 cells. HepG2 cells treated with various concentration of hesperidin undergo a distinct type of programed cell death. Cytoplasmic vacuolization, mitochondria and endoplasmic reticulum swelling and uncondensed chromatin were observed in hesperidin treated cells. DNA electrophoresis show lack of DNA fragmentation and western blot analysis demonstrates lack of caspase activation and PARP cleavage. It was observed that hesperidin induced cell death is nonautophagic and also activate mitogen activated protein kinase ERK1/2. Taken together, the data indicate that hesperidin induces paraptosis like cell death in HepG2 cells with the activation of ERK1/2. Thus our finding suggests that hesperidin inducing paraptosis may offer an alternative tool in human liver carcinoma therapy. PMID:24977707

  16. Sodium valproate induces mitochondrial respiration dysfunction in HepG2 in vitro cell model.

    Science.gov (United States)

    Komulainen, Tuomas; Lodge, Tiffany; Hinttala, Reetta; Bolszak, Maija; Pietilä, Mika; Koivunen, Peppi; Hakkola, Jukka; Poulton, Joanna; Morten, Karl J; Uusimaa, Johanna

    2015-05-04

    Sodium valproate (VPA) is a potentially hepatotoxic antiepileptic drug. Risk of VPA-induced hepatotoxicity is increased in patients with mitochondrial diseases and especially in patients with POLG1 gene mutations. We used a HepG2 cell in vitro model to investigate the effect of VPA on mitochondrial activity. Cells were incubated in glucose medium and mitochondrial respiration-inducing medium supplemented with galactose and pyruvate. VPA treatments were carried out at concentrations of 0-2.0mM for 24-72 h. In both media, VPA caused decrease in oxygen consumption rates and mitochondrial membrane potential. VPA exposure led to depleted ATP levels in HepG2 cells incubated in galactose medium suggesting dysfunction in mitochondrial ATP production. In addition, VPA exposure for 72 h increased levels of mitochondrial reactive oxygen species (ROS), but adversely decreased protein levels of mitochondrial superoxide dismutase SOD2, suggesting oxidative stress caused by impaired elimination of mitochondrial ROS and a novel pathomechanism related to VPA toxicity. Increased cell death and decrease in cell number was detected under both metabolic conditions. However, immunoblotting did not show any changes in the protein levels of the catalytic subunit A of mitochondrial DNA polymerase γ, the mitochondrial respiratory chain complexes I, II and IV, ATP synthase, E3 subunit dihydrolipoyl dehydrogenase of pyruvate dehydrogenase, 2-oxoglutarate dehydrogenase and glutathione peroxidase. Our results show that VPA inhibits mitochondrial respiration and leads to mitochondrial dysfunction, oxidative stress and increased cell death, thus suggesting an essential role of mitochondria in VPA-induced hepatotoxicity. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  17. Cyclosporine A and palmitic acid treatment synergistically induce cytotoxicity in HepG2 cells

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Yi, E-mail: yi.luo@pfizer.com; Rana, Payal; Will, Yvonne

    2012-06-01

    Immunosuppressant cyclosporine A (CsA) treatment can cause severe side effects. Patients taking immunosuppressant after organ transplantation often display hyperlipidemia and obesity. Elevated levels of free fatty acids have been linked to the etiology of metabolic syndromes, nonalcoholic fatty liver and steatohepatitis. The contribution of free fatty acids to CsA-induced toxicity is not known. In this study we explored the effect of palmitic acid on CsA-induced toxicity in HepG2 cells. CsA by itself at therapeutic exposure levels did not induce detectible cytotoxicity in HepG2 cells. Co-treatment of palmitic acid and CsA resulted in a dose dependent increase in cytotoxicity, suggesting that fatty acid could sensitize cells to CsA-induced cytotoxicity at the therapeutic doses of CsA. A synergized induction of caspase-3/7 activity was also observed, indicating that apoptosis may contribute to the cytotoxicity. We demonstrated that CsA reduced cellular oxygen consumption which was further exacerbated by palmitic acid, implicating that impaired mitochondrial respiration might be an underlying mechanism for the enhanced toxicity. Inhibition of c-Jun N-terminal kinase (JNK) attenuated palmitic acid and CsA induced toxicity, suggesting that JNK activation plays an important role in mediating the enhanced palmitic acid/CsA-induced toxicity. Our data suggest that elevated FFA levels, especially saturated FFA such as palmitic acid, may be predisposing factors for CsA toxicity, and patients with underlying diseases that would elevate free fatty acids may be susceptible to CsA-induced toxicity. Furthermore, hyperlipidemia/obesity resulting from immunosuppressive therapy may aggravate CsA-induced toxicity and worsen the outcome in transplant patients. -- Highlights: ► Palmitic acid and cyclosporine (CsA) synergistically increased cytotoxicity. ► The impairment of mitochondrial functions may contribute to the enhanced toxicity. ► Inhibition of JNK activity attenuated

  18. Two Trichothecene Mycotoxins from Myrothecium roridum Induce Apoptosis of HepG-2 Cells via Caspase Activation and Disruption of Mitochondrial Membrane Potential.

    Science.gov (United States)

    Ye, Wei; Chen, Yuchan; Li, Haohua; Zhang, Weimin; Liu, Hongxin; Sun, Zhanghua; Liu, Taomei; Li, Saini

    2016-06-17

    Trichothecene mycotoxins are a type of sesquiterpenoid produced by various kinds of plantpathogenic fungi. In this study, two trichothecene toxins, namely, a novel cytotoxic epiroridin acid and a known trichothecene, mytoxin B, were isolated from the endophytic fungus Myrothecium roridum derived from the medicinal plant Pogostemon cablin. The two trichothecene mytoxins were confirmed to induce the apoptosis of HepG-2 cells by cytomorphology inspection, DNA fragmentation detection, and flow cytometry assay. The cytotoxic mechanisms of the two mycotoxins were investigated by quantitative real time polymerase chain reaction, western blot, and detection of mitochondrial membrane potential. The results showed that the two trichothecene mycotoxins induced the apoptosis of cancer cell HepG-2 via activation of caspase-9 and caspase-3, up-regulation of bax gene expression, down-regulation of bcl-2 gene expression, and disruption of the mitochondrial membrane potential of the HepG-2 cell. This study is the first to report on the cytotoxic mechanism of trichothecene mycotoxins from M. roridum. This study provides new clues for the development of attenuated trichothecene toxins in future treatment of liver cancer.

  19. Inflammation response at the transcriptional level of HepG2 cells induced by multi-walled carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Piret, Jean-Pascal; Vankoningsloo, Sebastien; Noel, Florence; Saout, Christelle; Toussaint, Olivier [Research Unit in Cellular Biology (URBC), Narilis, University of Namur, 5000 Namur (Belgium); Mendoza, Jorge Mejia; Lucas, Stephane, E-mail: olivier.toussaint@fundp.ac.be [Research Center for the Physics of Matter and Radiation (PMR), Narilis, University of Namur, 5000 Namur (Belgium)

    2011-07-06

    Poor information are currently available about the biological effects of multi-walled carbon nanotubes (MWCNT) on the liver. In this study, we evaluated the effects of MWCNT at the transcriptional level on the classical in vitro model of HepG2 hepatocarcinoma cells. The expression levels of 96 transcript species implicated in the inflammatory and immune responses was studied after a 24h incubation of HepG2 cells in presence of raw MWCNT dispersed in water by stirring. Among the 46 transcript species detected, only a few transcripts including mRNA coding for interleukine-7, chemokines receptor of the C-C families CCR7, as well as Endothelin-1, were statistically more abundant after treatment with MWCNT. Altogether, these data indicate that MWCNT can only induce a weak inflammatory response in HepG2 cells.

  20. Inflammation response at the transcriptional level of HepG2 cells induced by multi-walled carbon nanotubes

    Science.gov (United States)

    Piret, Jean-Pascal; Vankoningsloo, Sébastien; Noël, Florence; Mejia Mendoza, Jorge; Lucas, Stéphane; Saout, Christelle; Toussaint, Olivier

    2011-07-01

    Poor information are currently available about the biological effects of multi-walled carbon nanotubes (MWCNT) on the liver. In this study, we evaluated the effects of MWCNT at the transcriptional level on the classical in vitro model of HepG2 hepatocarcinoma cells. The expression levels of 96 transcript species implicated in the inflammatory and immune responses was studied after a 24h incubation of HepG2 cells in presence of raw MWCNT dispersed in water by stirring. Among the 46 transcript species detected, only a few transcripts including mRNA coding for interleukine-7, chemokines receptor of the C-C families CCR7, as well as Endothelin-1, were statistically more abundant after treatment with MWCNT. Altogether, these data indicate that MWCNT can only induce a weak inflammatory response in HepG2 cells.

  1. Analysis of relationship between apoptosis and change of Ca2+ in HepG-2 induced by CSA with laser scanning confocal technology

    Science.gov (United States)

    Ji, Yu-bin; Yu, Lei

    2008-12-01

    Laser scanning confoncal technology was used to study relationship between apoptosis and change of Ca2+ induced by CSA (Capparis spinosa L. total alkaloid, CSA) on human heptocarcinoma cell HepG-2. Killing effect of CSA on human heptocarcinoma cell HepG-2 was measured by MTT method, while morphological observation of HepG-2 cells was completed by fluorescence microscope. Apoptosis induced by CSA on HepG-2 cells was measured by flowcytometry. In addition, change of intracellular Ca2+ level of CSA on HepG-2 cells was observed by laser scanning confocal microscope. As a result, CSA had obvious cytotoxicity on HepG-2 in a dose-dependent manner, and its IC50 was 162.4μg/ml. CSA could induce characteristic apoptosic morphology of HepG-2 cells, and apoptosis percentage was significantly higher than control one. Migration of cells cycle from S phase to G2 phase had been blocked by CSA. Concentration of Ca2+ in HepG-2 had been increased by CSA, which was positive correlation with drug dosage. CSA had obvious effect of killing and inducing apoptosis on human heptocarcinoma cell HepG-2, and overload of Ca2+ might be invovled in these events.

  2. Role of metabolism by the human intestinal microflora in arbutin-induced cytotoxicity in HepG2 cell cultures.

    Science.gov (United States)

    Khanal, Tilak; Kim, Hyung Gyun; Hwang, Yong Pil; Kong, Min Jeong; Kang, Mi Jeong; Yeo, Hee Kyung; Kim, Dong Hyun; Jeong, Tae Cheon; Jeong, Hye Gwang

    2011-09-23

    A possible role for metabolism by the human intestinal microflora in arbutin-induced cytotoxicity was investigated using human hepatoma HepG2 cells. When the cytotoxic effects of arbutin and hydroquinone (HQ), a deglycosylated metabolite of arbutin, were compared, HQ was more toxic than arbutin. Incubation of arbutin with a human fecal preparation could produce HQ. Following incubation of arbutin with a human fecal preparation for metabolic activation, the reaction mixture was filter-sterilized to test its toxic effects on HepG2 cells. The mixture induced cytotoxicity in HepG2 cells in a concentration-dependent manner. In addition, the mixture considerably inhibited expression of Bcl-2 together with an increase in Bax expression. Likewise, activation stimulated cleavage of caspase-3 and production of reactive oxygen species in HepG2 cell cultures. Furthermore, induction of apoptosis by the intestinal microflora reaction mixture was confirmed by the terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick-end labeling assay. Taken together, these findings suggest that the human intestinal microflora is capable of metabolizing arbutin to HQ, which can induce apoptosis in mammalian cells. Copyright © 2011 Elsevier Inc. All rights reserved.

  3. HBV X Protein induces overexpression of HERV-W env through NF-κB in HepG2 cells.

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    Liu, Cong; Liu, Lijuan; Wang, Xiuling; Liu, Youyi; Wang, Miao; Zhu, Fan

    2017-06-20

    Human endogenous retrovirus W family (HERV-W) envelope (env) at chromosome 7 is highly expressed in the placenta and possesses fusogenic activity in trophoblast development. HERV-W env has been found to be overexpressed in some cancers and immune diseases. Viral transactivators can induce the overexpression of HERV-W env in human cell lines. Hepatitis B virus X protein (HBx) is believed to be a multifunctional oncogenic protein. Here, we reported that HBx could increase the promoter activity of HERV-W env and upregulate the mRNA levels of non-spliced and spliced HERV-W env and also its protein in human hepatoma HepG2 cells. Interestingly, we found that the inhibition of nuclear factor κB (NF-κB) using shRNA targeting NF-κB/p65 or PDTC (an inhibitor of NF-κB) could attenuate the upregulation of HERV-W env induced by HBx. These suggested that HBx might upregulate the expression of HERV-W env through NF-κB in HepG2 cells. This study might provide a new insight in HBV-associated liver diseases including HCC.

  4. Curcumin induced nanoscale CD44 molecular redistribution and antigen-antibody interaction on HepG2 cell surface

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    Wang Mu [Department of Chemistry, Jinan University, 601 Huangpu Road West, Tianhe District, Guangzhou 510632 (China); Ruan Yuxia [Department of Ophthalmology, The First Affiliated Hospital, Jinan University, 601 Huangpu Road West, Tianhe District, Guangzhou 510632 (China); Xing Xiaobo; Chen Qian; Peng, Yuan [Department of Chemistry, Jinan University, 601 Huangpu Road West, Tianhe District, Guangzhou 510632 (China); Cai Jiye, E-mail: tjycai@jnu.edu.cn [Department of Chemistry, Jinan University, 601 Huangpu Road West, Tianhe District, Guangzhou 510632 (China)

    2011-07-04

    Graphical abstract: Highlights: > In this study, we investigate the changes of CD44 expression and distribution on HepG2 cells after curcumin treatment. > We find curcumin is able to change the morphology and ultrastructure of HepG2 cells. > Curcumin can reduce the expression of CD44 molecules and induce the nanoscale molecular redistribution on cell surface. > The binding force between CD44-modified AFM tip and the HepG2 cell surface decreases after curcumin-treatment. - Abstract: The cell surface glycoprotein CD44 was implicated in the progression, metastasis and apoptosis of certain human tumors. In this study, we used atomic force microscope (AFM) to monitor the effect of curcumin on human hepatocellular carcinoma (HepG2) cell surface nanoscale structure. High-resolution imaging revealed that cell morphology and ultrastructure changed a lot after being treated with curcumin. The membrane average roughness increased (10.88 {+-} 4.62 nm to 129.70 {+-} 43.72 nm) and the expression of CD44 decreased (99.79 {+-} 0.16% to 75.14 {+-} 8.37%). Laser scanning confocal microscope (LSCM) imaging showed that CD44 molecules were located on the cell membrane. The florescence intensity in control group was weaker than that in curcumin treated cells. Most of the binding forces between CD44 antibodies and untreated HepG2 cell membrane were around 120-220 pN. After being incubated with curcumin, the major forces focused on 70-150 pN (10 {mu}M curcumin-treated) and 50-120 pN (20 {mu}M curcumin-treated). These results suggested that, as result of nanoscale molecular redistribution, changes of the cell surface were in response to external treatment of curcumin. The combination of AFM and LSCM could be a powerful method to detect the distribution of cell surface molecules and interactions between molecules and their ligands.

  5. Alantolactone Induces Apoptosis in HepG2 Cells through GSH Depletion, Inhibition of STAT3 Activation, and Mitochondrial Dysfunction

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    Muhammad Khan

    2013-01-01

    Full Text Available Signal transducer and activator of transcription 3 (STAT3 constitutively expresses in human liver cancer cells and has been implicated in apoptosis resistance and tumorigenesis. Alantolactone, a sesquiterpene lactone, has been shown to possess anticancer activities in various cancer cell lines. In our previous report, we showed that alantolactone induced apoptosis in U87 glioblastoma cells via GSH depletion and ROS generation. However, the molecular mechanism of GSH depletion remained unexplored. The present study was conducted to envisage the molecular mechanism of alantolactone-induced apoptosis in HepG2 cells by focusing on the molecular mechanism of GSH depletion and its effect on STAT3 activation. We found that alantolactone induced apoptosis in HepG2 cells in a dose-dependent manner. This alantolactone-induced apoptosis was found to be associated with GSH depletion, inhibition of STAT3 activation, ROS generation, mitochondrial transmembrane potential dissipation, and increased Bax/Bcl-2 ratio and caspase-3 activation. This alantolactone-induced apoptosis and GSH depletion were effectively inhibited or abrogated by a thiol antioxidant, N-acetyl-L-cysteine (NAC. The data demonstrate clearly that intracellular GSH plays a central role in alantolactone-induced apoptosis in HepG2 cells. Thus, alantolactone may become a lead chemotherapeutic candidate for the treatment of liver cancer.

  6. Diosgenin Induces Apoptosis in HepG2 Cells through Generation of Reactive Oxygen Species and Mitochondrial Pathway

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    Dae Sung Kim

    2012-01-01

    Full Text Available Diosgenin, a naturally occurring steroid saponin found abundantly in legumes and yams, is a precursor of various synthetic steroidal drugs. Diosgenin is studied for the mechanism of its action in apoptotic pathway in human hepatocellular carcinoma cells. Based on DAPI staining, diosgenin-treated cells manifested nuclear shrinkage, condensation, and fragmentation. Treatment of HepG2 cells with 40 μM diosgenin resulted in activation of the caspase-3, -8, -9 and cleavage of poly-ADP-ribose polymerase (PARP and the release of cytochrome c. In the upstream, diosgenin increased the expression of Bax, decreased the expression of Bid and Bcl-2, and augmented the Bax/Bcl-2 ratio. Diosgenin-induced, dose-dependent induction of apoptosis was accompanied by sustained phosphorylation of JNK, p38 MAPK and apoptosis signal-regulating kinase (ASK-1, as well as generation of the ROS. NAC administration, a scavenger of ROS, reversed diosgene-induced cell death. These results suggest that diosgenin-induced apoptosis in HepG2 cells through Bcl-2 protein family-mediated mitochndria/caspase-3-dependent pathway. Also, diosgenin strongly generated ROS and this oxidative stress might induce apoptosis through activation of ASK1, which are critical upstream signals for JNK/p38 MAPK activation in HepG2 cancer cells.

  7. Implications of altered glutathione metabolism in aspirin-induced oxidative stress and mitochondrial dysfunction in HepG2 cells.

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    Haider Raza

    Full Text Available We have previously reported that acetylsalicylic acid (aspirin, ASA induces cell cycle arrest, oxidative stress and mitochondrial dysfunction in HepG2 cells. In the present study, we have further elucidated that altered glutathione (GSH-redox metabolism in HepG2 cells play a critical role in ASA-induced cytotoxicity. Using selected doses and time point for ASA toxicity, we have demonstrated that when GSH synthesis is inhibited in HepG2 cells by buthionine sulfoximine (BSO, prior to ASA treatment, cytotoxicity of the drug is augmented. On the other hand, when GSH-depleted cells were treated with N-acetyl cysteine (NAC, cytotoxicity/apoptosis caused by ASA was attenuated with a significant recovery in oxidative stress, GSH homeostasis, DNA fragmentation and some of the mitochondrial functions. NAC treatment, however, had no significant effects on the drug-induced inhibition of mitochondrial aconitase activity and ATP synthesis in GSH-depleted cells. Our results have confirmed that aspirin increases apoptosis by increased reactive oxygen species production, loss of mitochondrial membrane potential and inhibition of mitochondrial respiratory functions. These effects were further amplified when GSH-depleted cells were treated with ASA. We have also shown that some of the effects of aspirin might be associated with reduced GSH homeostasis, as treatment of cells with NAC attenuated the effects of BSO and aspirin. Our results strongly suggest that GSH dependent redox homeostasis in HepG2 cells is critical in preserving mitochondrial functions and preventing oxidative stress associated complications caused by aspirin treatment.

  8. Implications of altered glutathione metabolism in aspirin-induced oxidative stress and mitochondrial dysfunction in HepG2 cells.

    Science.gov (United States)

    Raza, Haider; John, Annie

    2012-01-01

    We have previously reported that acetylsalicylic acid (aspirin, ASA) induces cell cycle arrest, oxidative stress and mitochondrial dysfunction in HepG2 cells. In the present study, we have further elucidated that altered glutathione (GSH)-redox metabolism in HepG2 cells play a critical role in ASA-induced cytotoxicity. Using selected doses and time point for ASA toxicity, we have demonstrated that when GSH synthesis is inhibited in HepG2 cells by buthionine sulfoximine (BSO), prior to ASA treatment, cytotoxicity of the drug is augmented. On the other hand, when GSH-depleted cells were treated with N-acetyl cysteine (NAC), cytotoxicity/apoptosis caused by ASA was attenuated with a significant recovery in oxidative stress, GSH homeostasis, DNA fragmentation and some of the mitochondrial functions. NAC treatment, however, had no significant effects on the drug-induced inhibition of mitochondrial aconitase activity and ATP synthesis in GSH-depleted cells. Our results have confirmed that aspirin increases apoptosis by increased reactive oxygen species production, loss of mitochondrial membrane potential and inhibition of mitochondrial respiratory functions. These effects were further amplified when GSH-depleted cells were treated with ASA. We have also shown that some of the effects of aspirin might be associated with reduced GSH homeostasis, as treatment of cells with NAC attenuated the effects of BSO and aspirin. Our results strongly suggest that GSH dependent redox homeostasis in HepG2 cells is critical in preserving mitochondrial functions and preventing oxidative stress associated complications caused by aspirin treatment.

  9. Heat Killed Attenuated Leishmania Induces Apoptosis of HepG2 Cells Through ROS Mediated p53 Dependent Mitochondrial Pathway.

    Science.gov (United States)

    Bose, Dipayan; Banerjee, Somenath; Das, Subhadip; Chatterjee, Nabanita; Saha, Krishna Das

    2016-01-01

    Cytotoxic effect of attenuated Leishmania on liver cancer cells by inducing ROS generation. Spectrophotometric study to analyze cell death and levels of different active caspases. Flow cytometric study was done to analyze apoptosis induction and ROS generation and levels of different protein. Western blot analysis was performed to study the levels of protein. Confocal microscopy was done to ascertain the expression of different apoptotic markers. We have now observed that attenuated Leishmania donovani UR6 also has potentiality towards growth inhibition of HepG2 cells and investigated the mechanism of action. The effect is associated with increased DNA fragmentation, rise in number of annexinV positive cells, and cell cycle arrest at G1 phase. The detection of unregulated levels of active PARP, cleaved caspases 3 and 9, cytosolic cytochrome C, Bax, and Bad, along with the observed downregulation of Bcl-2 and loss of mitochondrial membrane potential suggested the involvement of mitochondrial pathway. Enhanced ROS and p53 levels regulate the apoptosis of HepG2 cells. NAC was found to inhibit p53 production but PFT-α has no effect on ROS generation. In conclusion, Leishmania donovani UR6 efficiently induces apoptosis in HepG2 cells through ROS mediated p53 dependent mitochondrial pathway. It has been reported earlier that some parasites show prominent cytotoxic effect and prevent tumor growth. From our study we found that Leishmania donovani UR6 efficiently induced apoptosis in HepG2 cells through ROS mediated p53 dependent mitochondrial pathway. This study has rejuvenated the age old idea of bio-therapy. © 2016 The Author(s) Published by S. Karger AG, Basel.

  10. Heat Killed Attenuated Leishmania Induces Apoptosis of HepG2 Cells Through ROS Mediated p53 Dependent Mitochondrial Pathway

    Directory of Open Access Journals (Sweden)

    Dipayan Bose

    2016-03-01

    Full Text Available Background/Aims: Cytotoxic effect of attenuated Leishmania on liver cancer cells by inducing ROS generation. Methods: Spectrophotometric study to analyze cell death and levels of different active caspases. Flow cytometric study was done to analyze apoptosis induction and ROS generation and levels of different protein. Western blot analysis was performed to study the levels of protein. Confocal microscopy was done to ascertain the expression of different apoptotic markers. Results: We have now observed that attenuated Leishmania donovani UR6 also has potentiality towards growth inhibition of HepG2 cells and investigated the mechanism of action. The effect is associated with increased DNA fragmentation, rise in number of annexinV positive cells, and cell cycle arrest at G1 phase. The detection of unregulated levels of active PARP, cleaved caspases 3 and 9, cytosolic cytochrome C, Bax, and Bad, along with the observed downregulation of Bcl-2 and loss of mitochondrial membrane potential suggested the involvement of mitochondrial pathway. Enhanced ROS and p53 levels regulate the apoptosis of HepG2 cells. NAC was found to inhibit p53 production but PFT-α has no effect on ROS generation. In conclusion, Leishmania donovani UR6 efficiently induces apoptosis in HepG2 cells through ROS mediated p53 dependent mitochondrial pathway. Conclusion: It has been reported earlier that some parasites show prominent cytotoxic effect and prevent tumor growth. From our study we found that Leishmania donovani UR6 efficiently induced apoptosis in HepG2 cells through ROS mediated p53 dependent mitochondrial pathway. This study has rejuvenated the age old idea of bio-therapy.

  11. Caffeine dose-dependently induces thermogenesis but restores ATP in HepG2 cells in culture.

    Science.gov (United States)

    Riedel, Annett; Pignitter, Marc; Hochkogler, Christina M; Rohm, Barbara; Walker, Jessica; Bytof, Gerhard; Lantz, Ingo; Somoza, Veronika

    2012-09-01

    Caffeine has been hypothesised as a thermogenic agent that might help to maintain a healthy body weight. Since very little is known about its actions on cellular energy metabolism, we investigated the effect of caffeine on mitochondrial oxidative phosphorylation, cellular energy supply and thermogenesis in HepG2 cells, and studied its action on fatty acid uptake and lipid accumulation in 3T3-L1 adipocytes at concentrations ranging from 30-1500 μM. In HepG2 cells, caffeine induced a depolarisation of the inner mitochondrial membrane, a feature of mitochondrial thermogenesis, both directly and after 24 h incubation. Increased concentrations of uncoupling protein-2 (UCP-2) also indicated a thermogenic activity of caffeine. Energy generating pathways, such as mitochondrial respiration, fatty acid oxidation and anaerobic lactate production, were attenuated by caffeine treatment. Nevertheless, HepG2 cells demonstrated a higher energy charge potential after exposure to caffeine that might result from energy restoration through attenuation of energy consuming pathways, as typically found in hibernating animals. In 3T3-L1 cells, in contrast, caffeine increased fatty acid uptake, but did not affect lipid accumulation. We provide evidence that caffeine stimulates thermogenesis but concomitantly causes energy restoration that may compensate enhanced energy expenditure.

  12. The effect of chitooligosaccharides on oleic acid-induced lipid accumulation in HepG2 cells

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    Peiqiu Cao

    2016-05-01

    Full Text Available This experiment aimed to evaluate the capacities of two types of chitooligosaccharides (COS with different molecular weights for the ability to eliminate lipid accumulation in hepatocytes. We have established a lipid accumulation model in HepG2 cells for these studies in vitro, which was established by induction with oleic acid. The capacity of COS to eliminate lipid accumulation was evaluated using three metrics: the thiazolyl blue dye absorbance (MTT value, the morphology of intracellular lipid droplets and the triglyceride level (TG. Two types of COS with different molecular weights (1000 Da and 3000 Da can significantly reduce intracellular lipid accumulation and decrease TG content in HepG2 cells, in a dose-dependent fashion. We found that low molecular weight COS is more efficacious than high molecular weight COS. Two types of COS can eliminate lipid accumulation induced by oleic acid in HepG2 cells, leading to an obvious hypolipidemic effect in vitro. These results suggest that COS may be effective preventive agents in fatty liver disease.

  13. Protective Effects of Sweet Orange, Unshiu Mikan, and Mini Tomato Juice Powders on t-BHP-Induced Oxidative Stress in HepG2 Cells.

    Science.gov (United States)

    Jannat, Susoma; Ali, Md Yousof; Kim, Hyeung-Rak; Jung, Hyun Ah; Choi, Jae Sue

    2016-09-01

    The aim of this study was to investigate the protective effects of juice powders from sweet orange [Citrus sinensis (L.) Osbeck], unshiu mikan (Citrus unshiu Marcow), and mini tomato (Solanum lycopersicum L.), and their major flavonoids, hesperidin, narirutin, and rutin in tert-butyl hydroperoxide (t-BHP)-induced oxidative stress in HepG2 cells. The increased reactive oxygen species and decreased glutathione levels observed in t-BHP-treated HepG2 cells were ameliorated by pretreatment with juice powders, indicating that the hepatoprotective effects of juice powders and their major flavonoids are mediated by induction of cellular defense against oxidative stress. Moreover, pretreatment with juice powders up-regulated phase-II genes such as heme oxygenase-1 (HO-1), thereby preventing cellular damage and the resultant increase in HO-1 expression. The high-performance liquid chromatography profiles of the juice powders confirmed that hesperidin, narirutin, and rutin were the key flavonoids present. Our results suggest that these fruit juice powders and their major flavonoids provide a significant cytoprotective effect against oxidative stress, which is most likely due to the flavonoid-related bioactive compounds present, leading to the normal redox status of cells. Therefore, these fruit juice powders could be advantageous as bioactive sources for the prevention of oxidative injury in hepatoma cells.

  14. Potassium Dichromate Induced Cytotoxicity, Genotoxicity and Oxidative Stress in Human Liver Carcinoma (HepG2 Cells

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    Diahanna Hackett

    2009-02-01

    Full Text Available Chromium is a widespread industrial waste. The soluble hexavalent chromium Cr (VI is an environmental contaminant widely recognized to act as a carcinogen, mutagen and teratogen towards humans and animals. The fate of chromium in the environment is dependent on its oxidation state. Hexavalent chromium primarily enters the cells and undergoes metabolic reduction to trivalent chromium, resulting in the formation of reactive oxygen species together with oxidative tissue damage and a cascade of cellular events. However, the results from in vitro studies are often conflicting. The aim of this study was to develop a model to establish relationships between cytotoxicity, genotoxicity and oxidative stress, in human liver carcinoma [HepG2] cells exposed to potassium dichromate. HepG2 cells were cultured following standard protocols and exposed to various concentrations [0-50 µM] of potassium dichromate [K2Cr2O7]. Following exposure to the toxic metal, the MTT assay was performed to assess the cytotoxicity, the thiobarbituric acid test to evaluate the degree of lipid peroxidation as an indicator of oxidative stress and the alkaline comet assay was used to assess DNA damage to study genotoxicity. The results of the study indicated that potassium dichromate was cytotoxic to HepG2 cells. The LD50 values of 8.83 ± 0.89 µg/ml, 6.76 ± 0.99 µg/ml, respectively, for cell mortality at 24 and 48 hrs were observed, indicating a dose- and time-dependent response with regard to the cytotoxic effects of potassium dichromate. A statistically significant increase in the concentration of malondialdehyde [MDA], an indicator of lipid peroxidation, was recorded in exposed cells [15.9 – 69.9 µM] compared to control [13 µM]. Similarly, a strong dose-response relationship (p<0.05 was also obtained with respect to potassium dichromate induced DNA damage (comet assay in HepG2 cells exposed [3.16 ± 0.70 – 24.84 ± 1.86 microns – mean comet tail length]; [12.4 ± 1

  15. Eicosapentaenoic acid (EPA) induced apoptosis in HepG2 cells through ROS-Ca(2+)-JNK mitochondrial pathways.

    Science.gov (United States)

    Zhang, Yuanyuan; Han, Lirong; Qi, Wentao; Cheng, Dai; Ma, Xiaolei; Hou, Lihua; Cao, Xiaohong; Wang, Chunling

    2015-01-24

    Eicosapentaenoic acid (EPA), a well-known dietary n-3 PUFAS, has been considered to inhibit proliferation of tumor cells. However, the molecular mechanism related to EPA-induced liver cancer cells apoptosis has not been reported. In this study, we investigated the effect of EPA on HepG2 cells proliferation and apoptosis mechanism through mitochondrial pathways. EPA inhibited proliferation of HepG2 cells in a dose-dependent manner and had no significant effect on the cell viability of humor normal liver L-02 cells. It was found that EPA initially evoked ROS formation, leading to [Ca(2+)]c accumulation and the mitochondrial permeability transition pore (MPTP) opening; EPA-induced HepG2 cells apoptosis was inhibited by N-acetylcysteine (NAC, an inhibitor of ROS), 1,2-bis (2-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid (BAPTA-AM, a chelator of calcium) and CsA (inhibitor of MPTP). The relationship between ROS production, the increase of cytoplasmic Ca and MPTP opening was detected. It seems that ROS may act as an upstream regulator of EPA-induced [Ca(2+)]c generation, moreover, generation of ROS, overload of mitochondrial [Ca(2+)]c, and JNK activated cause the opening of MPTP. Western blotting results showed that EPA elevated the phosphorylation status of JNK, processes associated with the ROS generation. Simultaneously, the apoptosis induced by EPA was related to release of cytochrome C from mitochondria to cytoplasm through the MPTP and activation of caspase-9 and caspase-3. These results suggest that EPA induces apoptosis through ROS-Ca(2+)-JNK mitochondrial pathways. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Hepatoprotective potential of Lavandula coronopifolia extracts against ethanol induced oxidative stress-mediated cytotoxicity in HepG2 cells.

    Science.gov (United States)

    Farshori, Nida Nayyar; Al-Sheddi, Ebtsam S; Al-Oqail, Mai M; Hassan, Wafaa H B; Al-Khedhairy, Abdulaziz A; Musarrat, Javed; Siddiqui, Maqsood A

    2015-08-01

    The present investigations were carried out to study the protective potential of four extracts (namely petroleum ether extract (LCR), chloroform extract (LCM), ethyl acetate extract (LCE), and alcoholic extract (LCL)) of Lavandula coronopifolia on oxidative stress-mediated cell death induced by ethanol, a known hepatotoxin in human hapatocellular carcinoma (HepG2) cells. Cells were pretreated with LCR, LCM, LCE, and LCL extracts (10-50 μg/ml) of L. coronopifolia for 24 h and then ethanol was added and incubated further for 24 h. After the exposure, cell viability using (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and neutral red uptake assays and morphological changes in HepG2 cells were studied. Pretreatment with various extracts of L. coronpifolia was found to be significantly effective in countering the cytotoxic responses of ethanol. Antioxidant properties of these L. coronopifolia extracts against reactive oxygen species (ROS) generation, lipid peroxidation (LPO), and glutathione (GSH) levels induced by ethanol were investigated. Results show that pretreatment with these extracts for 24 h significantly inhibited ROS generation and LPO induced and increased the GSH levels reduced by ethanol. The data from the study suggests that LCR, LCM, LCE, and LCL extracts of L. coronopifolia showed hepatoprotective activity against ethanol-induced damage in HepG2 cells. However, a comparative study revealed that the LCE extract was found to be the most effective and LCL the least effective. The hepatoprotective effects observed in the study could be associated with the antioxidant properties of these extracts of L. coronopifolia. © The Author(s) 2013.

  17. Stigmasterol isolated from marine microalgae Navicula incerta induces apoptosis in human hepatoma HepG2 cells.

    Science.gov (United States)

    Kim, Young-Sang; Li, Xi-Feng; Kang, Kyong-Hwa; Ryu, BoMi; Kim, Se Kwon

    2014-08-01

    Plant sterols have shown potent anti-proliferative effects and apoptosis induction against breast and prostate cancers. However, the effect of sterols against hepatic cancer has not been investigated. In the present study, we assessed whether the stigmasterol isolated from Navicula incerta possesses apoptosis inductive effect in hepatocarcimona (HepG2) cells. According to the results, Stigmasterol has up-regulated the expression of pro-apoptotic gene expressions (Bax, p53) while down-regulating the anti-apoptotic genes (Bcl-2). Probably via mitochondrial apoptosis signaling pathway. With the induction of apoptosis caspase-8, 9 were activated. The DNA damage and increase in apoptotic cell numbers were observed through Hoechst staining, annexin V staining and cell cycle analysis. According to these results, we can suggest that the stigmasterol shows potent apoptosis inductive effects and has the potential to be tested as an anti-cancer therapeutic against liver cancer.

  18. Caspase-independent cell death mediated by apoptosis-inducing factor (AIF) nuclear translocation is involved in ionizing radiation induced HepG2 cell death

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    Sun, Hengwen [Department of Radiation, Cancer Center of Guangdong General Hospital (Guangdong Academy of Medical Science), Guangzhou, 510080, Guangdong (China); Yang, Shana; Li, Jianhua [Department of Physiology, Guangzhou Medical University, Guangzhou, 510182, Guangdong (China); Zhang, Yajie [Department of Pathology, Guangzhou Medical University, Guangzhou, 510182, Guangdong (China); Gao, Dongsheng [Department of Oncology, Guangdong Medical College Affiliated Pengpai Memorial Hospital, Hai Feng, 516400, Gungdong (China); Zhao, Shenting, E-mail: zhaoshenting@126.com [Department of Physiology, Guangzhou Medical University, Guangzhou, 510182, Guangdong (China)

    2016-03-25

    Hepatocellular carcinoma (HCC) is the fifth most common cancer in the world. The aim of radiotherapy is to eradicate cancer cells with ionizing radiation. Except for the caspase-dependent mechanism, several lines of evidence demonstrated that caspase-independent mechanism is directly involved in the cell death responding to irradiation. For this reason, defining the contribution of caspase-independent molecular mechanisms represents the main goal in radiotherapy. In this study, we focused on the role of apoptosis-inducing factor (AIF), the caspase-independent molecular, in ionizing radiation induced hepatocellular carcinoma cell line (HepG2) cell death. We found that ionizing radiation has no function on AIF expression in HepG2 cells, but could induce AIF release from the mitochondria and translocate into nuclei. Inhibition of AIF could reduce ionizing radiation induced HepG2 cell death. These studies strongly support a direct relationship between AIF nuclear translocation and radiation induced cell death. What's more, AIF nuclear translocation is caspase-independent manner, but not caspase-dependent manner, in this process. These new findings add a further attractive point of investigation to better define the complex interplay between caspase-independent cell death and radiation therapy. - Highlights: • AIF nuclear translocation is involved in ionizing radiation induced hepatocellular carcinoma cell line HepG2 cell death. • AIF mediated cell death induced by ionizing radiation is caspase-independent. • Caspase-independent pathway is involved in ionzing radiation induced HepG2 cell death.

  19. The protective effects of carvacrol and thymol against paracetamol-induced toxicity on human hepatocellular carcinoma cell lines (HepG2).

    Science.gov (United States)

    Palabiyik, S S; Karakus, E; Halici, Z; Cadirci, E; Bayir, Y; Ayaz, G; Cinar, I

    2016-12-01

    Acetaminophen (APAP) overdose could induce liver damage and lead to acute liver failure. The treatment of APAP overdoses could be improved by new therapeutic strategies. Thymus spp., which has many beneficial effects and has been used in folk medicine, is one such potential strategy. In the present study, the hepatoprotective activity of the main constituents of Thymus spp., carvacrol and thymol, were evaluated in light of APAP-induced hepatotoxicity. We hoped to understand the hepatoprotective mechanism of these agents on the antioxidant system and pro-inflammatory cytokines in vitro. Dose-dependent effects of thymol and carvacrol (25, 50, and 100 µM) were tested on cultured HepG2 cells. N-Acetylcysteine (NAC) was tested as positive control. We showed that APAP inhibited HepG2 cell growth by inducing inflammation and oxidative stress. Incubating APAP-exposed HepG2 cells with carvacrol and thymol for 24 h ameliorated this inflammation and oxidative stress. We also evaluated alanine transaminase and lactate dehydrogenase levels of HepG2 cells. We found that thymol and carvacrol protected against APAP-induced toxicity in HepG2 cells by increasing antioxidant activity and reducing pro-inflammatory cytokines, such as tumor necrosis factor α and interleukin 1β. Taking together high-dose thymol and carvacrol treatment has an effect close to NAC treatment in APAP toxicity, but thymol has better treatment effect than carvacrol. © The Author(s) 2016.

  20. A chemically sulfated polysaccharide from Grifola frondos induces HepG2 cell apoptosis by notch1-NF-κB pathway.

    Science.gov (United States)

    Wang, Chun-ling; Meng, Meng; Liu, Sheng-bin; Wang, Li-rui; Hou, Li-hua; Cao, Xiao-hong

    2013-06-05

    Sulfated polysaccharides have been known to inhibit proliferation in tumor cells. However, the molecular mechanisms involved in sulfated polysaccharides-induced apoptosis are still uncharacterized. In this study, the effect of a chemically sulfated polysaccharide obtained from Grifola frondosa (S-GFB) on HepG2 cell proliferation and apoptosis-related mechanism were investigated. It was found that S-GFB inhibited proliferation of HepG2 cells in a dose-dependent manner with IC50 at 48 h of 61 μg ml(-1). The results of scanning electron micrographs indicated that S-GFB induced typical apoptotic morphological feature in HepG2 cells. Flow cytometric analysis demonstrated that S-GFB caused apoptosis of HepG2 cells through cells arrested at S phase. Western-blotting results showed that S-GFB inhibited notch1 expression, IκB-α degradation and NF-κB/p65 translocation from cytoplasm into nucleus. Simultaneously, the apoptotic mechanism of HepG2 cells induced by S-GFB was associated with down regulation of FLIP, and activation of caspase-3 and caspase-8. Taken together, these findings suggest that the S-GFB induces apoptosis through a notch1/NF-κB/p65-mediated caspase pathway. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  1. hesperidin induces paraptosis like cell death in hepatoblastoma, HepG2 Cells: involvement of ERK1/2 MAPK [corrected].

    Science.gov (United States)

    Yumnam, Silvia; Park, Hyeon Soo; Kim, Mun Ki; Nagappan, Arulkumar; Hong, Gyeong Eun; Lee, Ho Jeong; Lee, Won Sup; Kim, Eun Hee; Cho, Jae Hyeon; Shin, Sung Chul; Kim, Gon Sup

    2014-01-01

    Hesperidin, a natural flavonoid abundantly present in Citrus is known for its anti-cancer, anti-oxidant and anti-inflammatory properties. In this study we examined the effect of hesperidin on HepG2 cells. HepG2 cells treated with various concentration of hesperidin undergo a distinct type of programed cell death. Cytoplasmic vacuolization, mitochondria and endoplasmic reticulum swelling and uncondensed chromatin were observed in hesperidin treated cells. DNA electrophoresis show lack of DNA fragmentation and western blot analysis demonstrates lack of caspase activation and PARP cleavage. It was observed that hesperidin induced cell death is nonautophagic and also activate mitogen activated protein kinase ERK1/2. Taken together, the data indicate that hesperidin induces paraptosis like cell death in HepG2 cells with the activation of ERK1/2. Thus our finding suggests that hesperidin inducing paraptosis may offer an alternative tool in human liver carcinoma therapy.

  2. A Novel Polysaccharide Conjugate from Bullacta exarata Induces G1-Phase Arrest and Apoptosis in Human Hepatocellular Carcinoma HepG2 Cells.

    Science.gov (United States)

    Liao, Ningbo; Sun, Liang; Chen, Jiang; Zhong, Jianjun; Zhang, Yanjun; Zhang, Ronghua

    2017-03-01

    Bullacta exarata has been consumed in Asia, not only as a part of the normal diet, but also as a traditional Chinese medicine with liver- and kidney-benefitting functions. Several scientific investigations involving extraction of biomolecules from this mollusk and pharmacological studies on their biological activities have been carried out. However, little is known regarding the antitumor properties of polysaccharides from B. exarata , hence the polysaccharides from B. exarata have been investigated here. One polysaccharide conjugate BEPS-IA was isolated and purified from B. exarata . It mainly consisted of mannose and glucose in a molar ratio of 1:2, with an average molecular weight of 127 kDa. Thirteen general amino acids were identified to be components of the protein-bound polysaccharide. Methylation and NMR studies revealed that BEPS-IA is a heteropolysaccharide consisting of 1,4-linked-α-d-Glc, 1,6-linked-α-d-Man, 1,3,6-linked-α-d-Man, and 1-linked-α-d-Man residue, in a molar ratio of 6:1:1:1. In order to test the antitumor activity of BEPS-IA, we investigated its effect against the growth of human hepatocellular carcinoma cells HepG2 in vitro. The result showed that BEPS-IA dose-dependently exhibited an effective HepG2 cells growth inhibition with an IC 50 of 112.4 μg/mL. Flow cytometry analysis showed that BEPS-IA increased the populations of both apoptotic sub-G1 and G1 phase. The result obtained from TUNEL assay corroborated apoptosis which was shown in flow cytometry. Western blot analysis suggested that BEPS-IA induced apoptosis and growth inhibition were associated with up-regulation of p53, p21 and Bax, down-regulation of Bcl-2. These findings suggest that BEPS-IA may serve as a potential novel dietary agent for hepatocellular carcinoma.

  3. Citral, A Monoterpene Protect Against High Glucose Induced Oxidative Injury in HepG2 Cell In Vitro-An Experimental Study.

    Science.gov (United States)

    Subramaniyan, Sri Devi; Natarajan, Ashok Kumar

    2017-08-01

    Diabetes mellitus, a major metabolic disorder associated with hyperglycaemia is one of the leading cause of death in many developed countries. However, use of natural phytochemicals have been proved to have a protective effect against oxidative damage. To investigate the effect of citral, a monoterpene on high glucose induced cytotoxicity and oxidative stress in human hepatocellular liver carcinoma (Hep G2) cell line. Cells were treated with 50 mM concentration of glucose for 24 hours incubation following citral (30 μM) was added to confluent HepG2 cells. Cell viability, Reactive Oxygen Species (ROS) generation, DNA damage, lipid peroxidation, antioxidants and Mitogen Activated Protein Kinases (MAPKs) signaling were assessed in citral and/or high glucose induced HepG2 cells. Cells treated with glucose (50 mM), resulted in increased cytotoxicity, ROS generation, DNA damage, lipid peroxidation and depletion of enzymatic and non enzymatic antioxidants. In contrast, treatment with citral (30 μM) significantly decreased cell cytotoxicity, ROS generation, DNA damage, lipid peroxidation and increased antioxidants enzymes in high glucose induced HepG2 cells. In addition, the present study highlighted that high glucose treated cells showed increased expression of Extracellular Signal Regulated Protein Kinase-1 (ERK-1), c-Jun N-terminal Kinase (JNK) and p38 in HepG2 cells. On the other hand treatment with citral significantly suppressed the expression of ERK-1, JNK and p38 in high glucose induced HepG2 cells. Citral protects against high glucose induced oxidative stress through inhibiting ROS activated MAPK signaling pathway in HepG2 cells.

  4. PDE7B is involved in nandrolone decanoate hydrolysis in liver cytosol and its transcription is up-regulated by androgens in HepG2

    Directory of Open Access Journals (Sweden)

    Emmanuel eStrahm

    2014-05-01

    Full Text Available Most androgenic drugs are available as esters for a prolonged depot action. However the enzymes involved in the hydrolysis of the esters have not been identified. There is one study indicating that PDE7B may be involved in the activation of testosterone enanthate. The aims are to identify the cellular compartments where the hydrolysis of testosterone enanthate and nandrolone decanoate occurs, and to investigate the involvement of PDE7B in the activation. We also determined if testosterone and nandrolone affect the expression of the PDE7B gene. The hydrolysis studies were performed in isolated human liver cytosolic and microsomal preparations with and without specific PDE7B inhibitor. The gene expression was studied in human hepatoma cells (HepG2 exposed to testosterone and nandrolone. We show that PDE7B serves as a catalyst of the hydrolysis of testosterone enanthate and nandrolone decanoate in liver cytosol. The gene expression of PDE7B was significantly induced 3- and 5- fold after 2 hours exposure to 1 µM testosterone enanthate and nandrolone decanoate, respectively. These results show that PDE7B is involved in the activation of esterified nandrolone and testosterone and that the gene expression of PDE7B is induced by supra-physiological concentrations of androgenic drugs.

  5. Mercury-Induced Externalization of Phosphatidylserine and Caspase 3 Activation in Human Liver Carcinoma (HepG2 Cells

    Directory of Open Access Journals (Sweden)

    Paul B. Tchounwou

    2006-03-01

    Full Text Available Apoptosis arises from the active initiation and propagation of a series of highly orchestrated specific biochemical events leading to the demise of the cell. It is a normal physiological process, which occurs during embryonic development as well as in the maintenance of tissue homeostasis. Diverse groups of molecules are involved in the apoptosis pathway and it functions as a mechanism to eliminate unwanted or irreparably damaged cells. However, inappropriate induction of apoptosis by environmental agents has broad ranging pathologic implications and has been associated with several diseases including cancer. The toxicity of several heavy metals such as mercury has been attributed to their high affinity to sulfhydryl groups of proteins and enzymes, and their ability to disrupt cell cycle progression and/or apoptosis in various tissues. The aim of this study was to assess the potential for mercury to induce early and late-stage apoptosis in human liver carcinoma (HepG2 cells. The Annexin-V and Caspase 3 assays were performed by flow cytometric analysis to determine the extent of phosphatidylserine externalization and Caspase 3 activation in mercury-treated HepG2 cells. Cells were exposed to mercury for 10 and 48 hours respectively at doses of 0, 1, 2, and 3 μg/mL based on previous cytotoxicity results in our laboratory indicating an LD50 of 3.5 ± 0.6 μg/mL for mercury in HepG2 cells. The study data indicated a dose response relationship between mercury exposure and the degree of early and late-stage apoptosis in HepG2 cells. The percentages of cells undergoing early apoptosis were 0.03 ± 0.03%, 5.19 ± 0.04%, 6.36 ± 0.04%, and 8.84 ± 0.02% for 0, 1, 2, and 3 μg/mL of mercury respectively, indicating a gradual increase in apoptotic cells with increasing doses of mercury. The percentages of Caspase 3 positive cells undergoing late apoptosis were 3.58 ± 0.03%, 17.06 ± 0

  6. A resveratrol analog, phoyunbene B, induces G2/M cell cycle arrest and apoptosis in HepG2 liver cancer cells.

    Science.gov (United States)

    Wang, Guanghui; Guo, Xiaoyu; Chen, Haifeng; Lin, Ting; Xu, Yang; Chen, Quancheng; Liu, Jie; Zeng, Jinzhang; Zhang, Xiao-Kun; Yao, Xinsheng

    2012-03-01

    Among the seven natural resveratrol analogs separated and identified from Pholidota yunnanensis R(OLFE), we found phoyunbene B (PYB, trans-3,4'-dihydroxy-2',3',5-trimethoxystilbene) was more effective in inhibiting the growth of HepG2 hepatocellular carcinoma cells than resveratrol. The inhibitory effect of PYB in HepG2 cells was due to its induction of G2/M cell cycle arrest and apoptosis. Induction of G2/M phase cell cycle arrest by PYB was associated with its up-regulation of Cyclin B1, while its induction of apoptosis was accompanied with its down-regulation of Bcl-2 and up-regulation of Bax. Our in vitro invasion/migration assays also showed that PYB could inhibit the invasion of hepatocellular carcinoma cells. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Ashwagandha (Withania somnifera supercritical CO2 extract derived withanolides mitigates Bisphenol A induced mitochondrial toxicity in HepG2 cells

    Directory of Open Access Journals (Sweden)

    Satyakumar Vidyashankar

    2014-01-01

    Full Text Available Bisphenol A (BPA safety aspects on human health are debated extensively for long time. In the present study, we have studied the toxicity induced by BPA at no observed adverse effect level (NOAEL using HepG2 cells. We report that BPA at 100 nM induced cytotoxicity to HepG2 cells as determined by MTT assay at 0–72 h. The toxicity was result of reduced oxygen consumption and reduced mitochondrial membrane potential associated with decreased ATP production. The BPA treatment resulted in increase of malondialdehyde (MDA content with decreased glutathione and other antioxidant enzymes. BPA derived toxicity is a concern to human health and alternative non-toxic natural products/derivatives or adjuvants that serve as antidote will be relevant. In this context, Ashwagandha (Withania somnifera a widely used herb to treat arthritis, rheumatism and to improve longevity for time immemorial is investigated for its antidote effect. Ashwagandha supercritical CO2 extract derived Withanolides (ADW at 100 μg/ml protect HepG2 cells from BPA induced toxicity by suppressing mitochondrial damage and increased ATP production. Further, cellular MDA content was significantly suppressed with increased non-enzymic and antioxidant enzyme activities. These findings derived from the present study suggest the beneficial effect of ADW in mitigating BPA induced mitochondrial toxicity in HepG2 cells.

  8. Ashwagandha (Withania somnifera) supercritical CO2 extract derived withanolides mitigates Bisphenol A induced mitochondrial toxicity in HepG2 cells.

    Science.gov (United States)

    Vidyashankar, Satyakumar; Thiyagarajan, O S; Varma, R Sandeep; Kumar, L M Sharath; Babu, Uddagiri Venkanna; Patki, Pralhad Sadashiv

    2014-01-01

    Bisphenol A (BPA) safety aspects on human health are debated extensively for long time. In the present study, we have studied the toxicity induced by BPA at no observed adverse effect level (NOAEL) using HepG2 cells. We report that BPA at 100 nM induced cytotoxicity to HepG2 cells as determined by MTT assay at 0-72 h. The toxicity was result of reduced oxygen consumption and reduced mitochondrial membrane potential associated with decreased ATP production. The BPA treatment resulted in increase of malondialdehyde (MDA) content with decreased glutathione and other antioxidant enzymes. BPA derived toxicity is a concern to human health and alternative non-toxic natural products/derivatives or adjuvants that serve as antidote will be relevant. In this context, Ashwagandha (Withania somnifera) a widely used herb to treat arthritis, rheumatism and to improve longevity for time immemorial is investigated for its antidote effect. Ashwagandha supercritical CO2 extract derived Withanolides (ADW) at 100 μg/ml protect HepG2 cells from BPA induced toxicity by suppressing mitochondrial damage and increased ATP production. Further, cellular MDA content was significantly suppressed with increased non-enzymic and antioxidant enzyme activities. These findings derived from the present study suggest the beneficial effect of ADW in mitigating BPA induced mitochondrial toxicity in HepG2 cells.

  9. Cytotoxic effects induced by unmodified and organically modified nanoclays in the human hepatic HepG2 cell line.

    Science.gov (United States)

    Lordan, Sinéad; Kennedy, James E; Higginbotham, Clement L

    2011-01-01

    The term 'nanoclay' generically refers to the natural clay mineral, montmorillonite, with silica and alumina as the dominant constituents. The incorporation of nanoclays into polymeric systems dramatically enhances their barrier properties as well as their thermal and mechanical resistance. Consequently, nanoclays are employed in a wide range of industrial applications with recent studies reporting potential use in the modulation of drug release. With the increase in manufacturing of nanoclay-containing products, information on the toxicological and health effects of nanoclay exposure is warranted. Thus, the objective of the present study was to evaluate the cytotoxicity of two different nanoclays: the unmodified nanoclay, Cloisite Na+ ®, and the organically modified nanoclay, Cloisite 93A®, in human hepatoma HepG2 cells. Following 24 h exposure the nanoclays significantly decreased cell viability. Cloisite Na+ induced intracellular reactive oxygen species (ROS) formation which coincided with increased cell membrane damage, whilst ROS generation did not play a role in Cloisite 93A-induced cell death. Neither of the nanoclays induced caspase-3/7 activation. Moreover, in the cell culture medium the nanoclays aggregated differently and this appeared to have an effect on their mechanisms of toxicity. Taken together, our data demonstrate that nanoclays are highly cytotoxic and as a result pose a possible risk to human health. Copyright © 2010 John Wiley & Sons, Ltd.

  10. Hepatocellular carcinoma HepG2 cell apoptosis and caspase-8 and Bcl-2 expression induced by injectable seed extract of Coix lacryma-jobi.

    Science.gov (United States)

    Lu, Yun; Zhang, Bing-Yuan; Jia, Zhuo-Xia; Wu, Wen-Jin; Lu, Zheng-Qiao

    2011-06-01

    Many Chinese herbs, especially herbal injections, have been shown to have anti-tumor effects in recent years. However, since most reports focus on the clinical effectiveness of these herbs, their mechanisms of action are not well understood. In this study, we assessed apoptosis in the hepatocellular carcinoma (HCC) cell line HepG2 induced by an injectable extract from the seed of Coix lacryma-jobi (Semen coicis, SC), and monitored the expression of Bcl-2 and caspase-8. Injectable SC was applied to HepG2 cells at different concentrations and the cells were collected 12, 24 and 48 hours later. 5-fluorouracil was used as a positive control group, and fluorescence-activated cell-sorting cytometry was used to measure the apoptosis rate of HepG2 cells and the expression of Bcl-2 and caspase-8 proteins. SC induced apoptosis in HepG2 cells in a concentration- and time-dependent manner, and the expression of caspase-8 was elevated and prolonged. However, it did not significantly influence the expression of Bcl-2. Injectable SC may induce apoptosis in HCC cells by regulating the expression of caspase-8.

  11. Prevention of phosphine-induced cytotoxicity by nutrients in HepG2 cells

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    Marzieh Rashedinia

    2016-01-01

    Interpretation & conclusions: The results supported the hypothesis that phosphine-induced cytotoxicity was due to decrease of ATP levels. ATP suppliers could prevent its toxicity by generating ATP through glycolysis. α-keto compounds such as dihydroxyacetone and α-ketoglutarate may bind to phosphine and restore mitochondrial respiration.

  12. Cannabidiol induces expression of human cytochrome P450 1A1 that is possibly mediated through aryl hydrocarbon receptor signaling in HepG2 cells.

    Science.gov (United States)

    Yamaori, Satoshi; Kinugasa, Yuka; Jiang, Rongrong; Takeda, Shuso; Yamamoto, Ikuo; Watanabe, Kazuhito

    2015-09-01

    We herein investigated the inducibility of cytochrome P450 1A1 (CYP1A1) by Δ(9)-tetrahydrocannabinol, cannabidiol (CBD), and cannabinol, three major phytocannabinoids, using human hepatoma HepG2 cells. The expression of CYP1A1 and the aryl hydrocarbon receptor (AhR) was measured by a quantitative real-time polymerase chain reaction and/or Western blotting. Δ(9)-Tetrahydrocannabinol and CBD concentration-dependently induced the expression of CYP1A1 mRNA, whereas cannabinol showed little or no induction. Among the phytocannabinoids tested, CBD was the most potent inducer of CYP1A1 expression. The induction of CYP1A1 expression by CBD was significantly attenuated by the knockdown of AhR expression with AhR small interfering RNAs. The role of protein tyrosine kinases (PTKs) in the CBD-mediated induction of CYP1A1 was then examined using herbimycin A, a PTK inhibitor. The upregulation of CYP1A1 by CBD was significantly suppressed by herbimycin A as was the induction by omeprazole but not 3-methylcholanthrene. The inducibility of CYP1A1 by CBD-related compounds was examined to clarify the structural requirements for CBD-mediated CYP1A1 induction. Olivetol, which corresponds to the pentylresorcinol moiety of CBD, significantly induced the expression of CYP1A1, whereas d-limonene, CBD-2'-monomethyl ether, and CBD-2',6'-dimethyl ether did not. These results showed that CBD may have induced human CYP1A1 expression through the activation of PTK-dependent AhR signaling, in which two phenolic hydroxyl groups in the pentylresorcinol moiety of CBD may play structurally important roles. Copyright © 2015. Published by Elsevier Inc.

  13. Protective Effect of Curcumin against Ionizing Radiation (IR)-induced Cytotoxicity and Genotoxicity in HepG2 Cells

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Dong Min; Nasir Uddin, S. M.; Ryu, Tae Ho; Kang, Mi Young; Kim, Jin Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    Ionizing radiation (IR) has many practical applications such as medicine, foods, agricultures, industries, and research laboratories. However, the increasing use of radiation is associated with radiation accidents threatening human health. It is well known that exposure to IR gives rise to genomic alterations, mutagenesis, and cell death. IR is absorbed directly by DNA, leading to various DNA damages (single or double-strand breaks, base damage, and DNA-DNA or DNA-protein cross-linkages) in many living organisms. Therefore, the development of effective and nontoxic radioprotective agents is of considerable interest. Curcumin (C{sub 12}H{sub 20}O{sub 6}, structure is the major yellow component of Curcuma longa with biological activities (antioxidant, anti-proliferative and anti-inflammatory properties). It has been widely used as food and medicine for a long time. The aim of our present study is to investigate the protective effects of curcumin against IR-induced cytotoxicity and genotoxicity in cultured HepG2 cells.

  14. Alcohol dehydrogenase and cytochrome P450 2E1 can be induced by long-term exposure to ethanol in cultured liver HEP-G2 cells.

    Science.gov (United States)

    Balusikova, Kamila; Kovar, Jan

    2013-09-01

    It has been shown in previous studies that liver HEP-G2 cells (human hepatocellular carcinoma) lose their ability to express active alcohol dehydrogenase (ADH) and cytochrome P450 2E1 (CYP2E1). Although both are ethanol-inducible enzymes, short-term exposure to ethanol does not cause any changes in expression or activity in cultured HEP-G2 cells. Therefore, we tested the effect of long-term exposure to ethanol on the expression and activity of both ADH and CYP2E1 in these cells. The expression of ADH and CYP2E1 was assessed at the mRNA and/or protein level using real-time PCR and Western blot analysis. Specific colorimetric assays were used for the measurement of ADH and CYP2E1 enzymatic activities. Caco-2 cells (active CYP2E1 and inactive ADH) were used as control cells. Significantly increased protein expression of ADH (about 2.5-fold) as well as CYP2E1 (about 1.6-fold) was found in HEP-G2 cells after long-term (12 mo) exposure to ethanol. The activity of ADH and CYP2E1 was also significantly increased from 12 ± 3 and 6 ± 1 nmol/h/mg of total protein to 191 ± 9 and 57 ± 9 nmol/h/mg of total protein, respectively. We suggest that the loss of activity of ethanol-metabolizing enzymes in cultured HEP-G2 cells is reversible and can be induced by prolonged exposure to ethanol. We are therefore able to reactivate HEP-G2 cells metabolic functions concerning ethanol oxidation just by modification of in vitro culture conditions without necessity of transfection with its side effect - enzyme overexpression.

  15. A Novel Polysaccharide Conjugate from Bullacta exarata Induces G1-Phase Arrest and Apoptosis in Human Hepatocellular Carcinoma HepG2 Cells

    Directory of Open Access Journals (Sweden)

    Ningbo Liao

    2017-03-01

    Full Text Available Bullacta exarata has been consumed in Asia, not only as a part of the normal diet, but also as a traditional Chinese medicine with liver- and kidney-benefitting functions. Several scientific investigations involving extraction of biomolecules from this mollusk and pharmacological studies on their biological activities have been carried out. However, little is known regarding the antitumor properties of polysaccharides from B. exarata, hence the polysaccharides from B. exarata have been investigated here. One polysaccharide conjugate BEPS-IA was isolated and purified from B. exarata. It mainly consisted of mannose and glucose in a molar ratio of 1:2, with an average molecular weight of 127 kDa. Thirteen general amino acids were identified to be components of the protein-bound polysaccharide. Methylation and NMR studies revealed that BEPS-IA is a heteropolysaccharide consisting of 1,4-linked-α-d-Glc, 1,6-linked-α-d-Man, 1,3,6-linked-α-d-Man, and 1-linked-α-d-Man residue, in a molar ratio of 6:1:1:1. In order to test the antitumor activity of BEPS-IA, we investigated its effect against the growth of human hepatocellular carcinoma cells HepG2 in vitro. The result showed that BEPS-IA dose-dependently exhibited an effective HepG2 cells growth inhibition with an IC50 of 112.4 μg/mL. Flow cytometry analysis showed that BEPS-IA increased the populations of both apoptotic sub-G1 and G1 phase. The result obtained from TUNEL assay corroborated apoptosis which was shown in flow cytometry. Western blot analysis suggested that BEPS-IA induced apoptosis and growth inhibition were associated with up-regulation of p53, p21 and Bax, down-regulation of Bcl-2. These findings suggest that BEPS-IA may serve as a potential novel dietary agent for hepatocellular carcinoma.

  16. Lignans from Opuntia ficus-indica seeds protect rat primary hepatocytes and HepG2 cells against ethanol-induced oxidative stress.

    Science.gov (United States)

    Kim, Jung Wha; Yang, Heejung; Kim, Hyeon Woo; Kim, Hong Pyo; Sung, Sang Hyun

    2017-01-01

    Bioactivity-guided isolation of Opuntia ficus-indica (Cactaceae) seeds against ethanol-treated primary rat hepatocytes yielded six lignan compounds. Among the isolates, furofuran lignans 4-6, significantly protected rat hepatocytes against ethanol-induced oxidative stress by reducing intracellular reactive oxygen species levels, preserving antioxidative defense enzyme activities, and maintaining the glutathione content. Moreover, 4 dose-dependently induced the heme oxygenase-1 expression in HepG2 cells.

  17. LRD-22, a novel dual dithiocarbamatic acid ester, inhibits Aurora-A kinase and induces apoptosis and cell cycle arrest in HepG2 cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Huiling; Li, Ridong [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing (China); Li, Li [Department of Cell Biology, School of Basic Medical Sciences, Peking University, Beijing (China); Ge, Zemei [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing (China); Zhou, Rouli, E-mail: rlzhou@bjmu.edu.cn [Department of Cell Biology, School of Basic Medical Sciences, Peking University, Beijing (China); Li, Runtao, E-mail: lirt@bjmu.edu.cn [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing (China)

    2015-02-27

    In this study we investigated the antitumor activity of the novel dual dithiocarbamatic acid ester LRD-22 in vitro and in vivo. Several cancer cell lines were employed to determine the effect of LRD-22 on cell growth, and the MTT assay showed there was a significant decrease in viable tumor cell numbers in the presence of LRD-22, especially in the HepG2 cell line. Colony formation assay also showed LRD-22 strongly inhibits HepG2 cell growth. Evaluation of the mechanism involved showed that inhibitory effects of LRD-22 on cell growth are due to induction of apoptosis and G2/M arrest. LRD-22 inhibited Aurora-A phosphorylation at Thr{sub 288} and subsequently impaired p53 phosphorylation at Ser{sub 315} which was associated with the proteasome degradation pathway. Tumor suppressor protein p53 is stabilized by this mechanism and accumulates through inhibition of Aurora-A kinase activity via treatment with LRD-22. In vivo study of HepG2 xenograft in nude mice also shows LRD-22 suppresses tumor growth at a concentration of 5 mg/kg without animals suffering loss of body weight. In conclusion, our results demonstrate LRD-22 acts as an Aurora-A kinase inhibitor to induce apoptosis and inhibit proliferation in HepG2 cells, and should be considered as a promising targeting agent for HCC therapy. - Highlights: • LRD-22 significantly inhibits cancer cell growth, especially in the HepG2 cell line. • The inhibitory effect of LRD-22 is due to induction of apoptosis and cell cycle arrest. • LRD-22 inhibits Aurora-A phosphorylation which results in subsequent impairment of the p53 pathway. • LRD-22 suppresses tumor growth in xenograft mice without body weight loss.

  18. SIRT1 attenuates palmitate-induced endoplasmic reticulum stress and insulin resistance in HepG2 cells via induction of oxygen-regulated protein 150

    Science.gov (United States)

    Jung, T.W.; Lee, K.T.; Lee, M.W.; Ka, K.H.

    2012-01-01

    Endoplasmic reticulum (ER) stress has been implicated in the pathology of type 2 diabetes mellitus (T2DM). Although SIRT1 has a therapeutic effect on T2DM, the mechanisms by which SIRT1 ameliorates insulin resistance (IR) remain unclear. In this study, we investigated the impact of SIRT1 on palmitate-induced ER stress in HepG2 cells and its underlying signal pathway. Treatment with resveratrol, a SIRT1 activator significantly inhibited palmitate-induced ER stress, leading to the protection against palmitate-induced ER stress and insulin resistance. Resveratrol and SIRT1 overexpression induced the expression of oxygen-regulated protein (ORP) 150 in HepG2 cells. Forkhead box O1 (FOXO1) was involved in the regulation of ORP150 expression because suppression of FOXO1 inhibited the induction of ORP150 by SIRT1. Our results indicate a novel mechanism by which SIRT1 regulates ER stress by overexpression of ORP150, and suggest that SIRT1 ameliorates palmitate-induced insulin resistance in HepG2 cells via regulation of ER stress.

  19. N-Acetyl-L-Cysteine Affords Protection against Lead-Induced Cytotoxicity and Oxidative Stress in Human Liver Carcinoma (HepG2 Cells

    Directory of Open Access Journals (Sweden)

    Paul B. Tchounwou

    2007-06-01

    Full Text Available Although lead exposure has declined in recent years as a result of change to lead-free gasoline, several epidemiological have pointed out that it represents a medical and public health emergency, especially in young children consuming high amounts of lead-contaminated flake paints. A previous study in our laboratory indicated that lead exposure induces cytotoxicity in human liver carcinoma cells. In the present study, we evaluated the role of oxidative stress in lead-induced toxicity, and the protective effect of the anti-oxidant n-acetyl-l-cysteine (NAC. We hypothesized that oxidative stress plays a role in lead-induced cytotoxicity, and that NAC affords protection against this adverse effect. To test this hypothesis, we performed the MTT [3-(4, 5-dimethylthiazol-2-yl-2, 5-diphenyltetrazolium bromide] assay and the trypan blue exclusion test for cell viability. We also performed the thiobarbituric acid test for lipid peroxidation. Data obtained from the MTT assay indicated that NAC significantly increased the viability of HepG2 cells in a dosedependent manner upon 48 hours of exposure. Similar trend was obtained with the trypan blue exclusion test. Data generated from the thiobarbituric acid test showed a significant (p ≤ 0.05 increase of MDA levels in lead nitrate-treated HepG2 cells compared to control cells. Interestingly, the addition of NAC to lead nitrate-treated HepG2 cells significantly decreased cellular content of reactive oxygen species (ROS, as evidenced by the decrease in lipid peroxidation byproducts. Overall, findings from this study suggest that NAC inhibits lead nitrate-induced cytotoxicity and oxidative stress in HepG2 cells. Hence, NAC may be used as a salvage therapy for lead-induced toxicity in exposed persons.

  20. Copper(ii) oxide nanoparticles penetrate into HepG2 cells, exert cytotoxicity via oxidative stress and induce pro-inflammatory response

    Science.gov (United States)

    Piret, Jean-Pascal; Jacques, Diane; Audinot, Jean-Nicolas; Mejia, Jorge; Boilan, Emmanuelle; Noël, Florence; Fransolet, Maude; Demazy, Catherine; Lucas, Stéphane; Saout, Christelle; Toussaint, Olivier

    2012-10-01

    The potential toxic effects of two types of copper(ii) oxide (CuO) nanoparticles (NPs) with different specific surface areas, different shapes (rod or spheric), different sizes as raw materials and similar hydrodynamic diameter in suspension were studied on human hepatocarcinoma HepG2 cells. Both CuO NPs were shown to be able to enter into HepG2 cells and induce cellular toxicity by generating reactive oxygen species. CuO NPs increased the abundance of several transcripts coding for pro-inflammatory interleukins and chemokines. Transcriptomic data, siRNA knockdown and DNA binding activities suggested that Nrf2, NF-κB and AP-1 were implicated in the response of HepG2 cells to CuO NPs. CuO NP incubation also induced activation of MAPK pathways, ERKs and JNK/SAPK, playing a major role in the activation of AP-1. In addition, cytotoxicity, inflammatory and antioxidative responses and activation of intracellular transduction pathways induced by rod-shaped CuO NPs were more important than spherical CuO NPs. Measurement of Cu2+ released in cell culture medium suggested that Cu2+ cations released from CuO NPs were involved only to a small extent in the toxicity induced by these NPs on HepG2 cells.The potential toxic effects of two types of copper(ii) oxide (CuO) nanoparticles (NPs) with different specific surface areas, different shapes (rod or spheric), different sizes as raw materials and similar hydrodynamic diameter in suspension were studied on human hepatocarcinoma HepG2 cells. Both CuO NPs were shown to be able to enter into HepG2 cells and induce cellular toxicity by generating reactive oxygen species. CuO NPs increased the abundance of several transcripts coding for pro-inflammatory interleukins and chemokines. Transcriptomic data, siRNA knockdown and DNA binding activities suggested that Nrf2, NF-κB and AP-1 were implicated in the response of HepG2 cells to CuO NPs. CuO NP incubation also induced activation of MAPK pathways, ERKs and JNK/SAPK, playing a major

  1. The essential oils from Zanthoxylum schinifolium pericarp induce apoptosis of HepG2 human hepatoma cells through increased production of reactive oxygen species.

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    Paik, Soon-Young; Koh, Kyung-Hee; Beak, Sung-Mok; Paek, Seung-Hwan; Kim, Jung-Ae

    2005-05-01

    The volatile extract from dried pericarp of Zanthoxylum schinifolium that was obtained by simultaneous distillation with dichloromethane and water was composed of 29.9% geranyl acetate, 15.8% citronella, 15.4% sabinene and the minor volatile components included beta-myrcene, linalool, (-)-isopulegol, citronellyl acetate, 1,4-dimethyl pyrazole, alpha-terpinene, 3-methyl-6-(1-methylethyl)-2-cyclo-hexene-1-o1 and trans-geraniol. The volatile extract decreased the cell viability and induced apoptotic death in HepG2 human hepatoma cells in a concentration- and time-related manner. In addition, the volatile extract increased the production of reactive oxygen species in a dose-dependent manner. Pretreatment of the cells with Trolox, a well-known antioxidant, significantly suppressed the generation of reactive oxygen species and cell death induced by the extract. However, caspase-3 activity was not changed in the extract-treated cells, suggesting that the extract-induced apoptosis of HepG2 cells is caspase-3 independent. Furthermore, in nude mice inoculated with Huh-7 human hepatoma cells, the extract significantly inhibited tumor development. These results suggest that the volatile extract from Zanthoxylum schinifolium pericarpium is a good candidate for hepatocellular carcinoma (HCC) therapy and that reactive oxygen species are the key signaling molecules in the volatile extract-induced cell death in HepG2 cells.

  2. Zanthoxylum ailanthoides Suppresses Oleic Acid-Induced Lipid Accumulation through an Activation of LKB1/AMPK Pathway in HepG2 Cells

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    Eun-Bin Kwon

    2018-01-01

    Full Text Available Zanthoxylum ailanthoides (ZA has been used as folk medicines in East Asian and recently reported to have several bioactivity; however, the studies of ZA on the regulation of triacylglycerol (TG biosynthesis have not been elucidated yet. In this study, we examined whether the methanol extract of ZA (ZA-M could reduce oleic acid- (OA- induced intracellular lipid accumulation and confirmed its mode of action in HepG2 cells. ZA-M was shown to promote the phosphorylation of AMPK and its upstream LKB1, followed by reduction of lipogenic gene expressions. As a result, treatment of ZA-M blocked de novo TG biosynthesis and subsequently mitigated intracellular neutral lipid accumulation in HepG2 cells. ZA-M also inhibited OA-induced production of reactive oxygen species (ROS and TNF-α, suggesting that ZA-M possess the anti-inflammatory feature in fatty acid over accumulated condition. Taken together, these results suggest that ZA-M attenuates OA-induced lipid accumulation and inflammation through the activation of LKB1/AMPK signaling pathway in HepG2 cells.

  3. Isoorientin induces apoptosis through mitochondrial dysfunction and inhibition of PI3K/Akt signaling pathway in HepG2 cancer cells

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    Yuan, Li; Wang, Jing; Xiao, Haifang; Xiao, Chunxia; Wang, Yutang; Liu, Xuebo, E-mail: xueboliu@yahoo.com.cn

    2012-11-15

    Isoorientin (ISO) is a flavonoid compound that can be extracted from several plant species, such as Phyllostachys pubescens, Patrinia, and Drosophyllum lusitanicum; however, its biological activity remains poorly understood. The present study investigated the effects and putative mechanism of apoptosis induced by ISO in human hepatoblastoma cancer (HepG2) cells. The results showed that ISO induced cell death in a dose-dependent manner in HepG2 cells, but no toxicity in human liver cells (HL-7702) and buffalo rat liver cells (BRL-3A) treated with ISO at the indicated concentrations. ISO-induced cell death included apoptosis which characterized by the appearance of nuclear shrinkage, the cleavage of poly (ADP-ribose) polymerase (PARP) and DNA fragmentation. ISO significantly (p < 0.01) increased the Bax/Bcl-2 ratio, disrupted the mitochondrial membrane potential (MMP), increased the release of cytochrome c, activated caspase-3, and enhanced intracellular levels of reactive oxygen species (ROS) and nitric oxide (NO). In addition, ISO effectively inhibited the phosphorylation of Akt and increased FoxO4 expression. The PI3K/Akt inhibitor LY294002 enhanced the apoptosis-inducing effect of ISO. However, LY294002 markedly quenched ROS and NO generation and diminished the protein expression of heme peroxidase enzyme (HO-1) and inducible nitric oxide synthase (iNOS). Furthermore, the addition of a ROS inhibitor (N-acetyl cysteine, NAC) or iNOS inhibitor (N-[3-(aminomethyl) benzyl] acetamidine, dihydrochloride, 1400W) significantly diminished the apoptosis induced by ISO and also blocked the phosphorylation of Akt. These results demonstrated for the first time that ISO induces apoptosis in HepG2 cells and indicate that this apoptosis might be mediated through mitochondrial dysfunction and PI3K/Akt signaling pathway, and has no toxicity in normal liver cells, suggesting that ISO may have good potential as a therapeutic and chemopreventive agent for liver cancer. Highlights:

  4. The Role of Oxidative Stress in Koenimbine-Induced DNA Damage and Heat Shock Protein Modulation in HepG2 Cells.

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    Hobani, Yahya Hasan

    2017-12-01

    Murraya koenigii (L.) Spreng, is a significant herb of traditional Ayurvedic system of medicine. Koenimbine, a carbazole alkaloid isolated from this plant holds antiproliferative and apoptotic effects. The aim of this study was to assess koenimbine-induced DNA damage and to clarify the role of free radicals in cell death mechanisms, using HepG2 cells. The level of cytotoxicity was assayed by MTT assay. To elucidate the role of glutathione (GSH), the intracellular GSH level was analyzed. The effect of koenimbine in the cell mitochondria was evaluated using mitochondrial membrane potential (MMP) changes. Single cell gel electrophoresis assay was used to examine the level of DNA damage. Heat shock proteins, Hsp 70 and Hsp 90 expressions were checked at mRNA and protein level. Ascorbic acid and catalase were used as control antioxidants. It was observed that koenimbine considerably increased DNA damage in HepG2 cells at subcytotoxic concentrations. Koenimbine induced the increased levels of reactive oxygen species (ROS) and reduction of GSH level in HepG2 cells, together with time-dependent loss of MMP. In addition, results clearly showed that koenimbine encouraged cells to express Hsp 70 and Hsp 90 in a concentration-dependent manner up to a concentration of 100 µM and a time-dependent manner at 24-hour incubation both at transcriptional and translational levels. The antioxidant capacity of ascorbic acid was found to be not as prominent as to catalase throughout the study. Based on these data it can be concluded that koenimbine causes DNA strand breaks in HepG2 cells, probably through oxidative stress. Moreover, the oxidative stress induced was closely associated with MMP reduction and GSH depletion associated with HSP modulation at subcytotoxic concentration.

  5. The Role of Oxidative Stress in Koenimbine-Induced DNA Damage and Heat Shock Protein Modulation in HepG2 Cells

    Science.gov (United States)

    Hobani, Yahya Hasan

    2016-01-01

    Background. Murraya koenigii (L.) Spreng, is a significant herb of traditional Ayurvedic system of medicine. Koenimbine, a carbazole alkaloid isolated from this plant holds antiproliferative and apoptotic effects. The aim of this study was to assess koenimbine-induced DNA damage and to clarify the role of free radicals in cell death mechanisms, using HepG2 cells. Methods. The level of cytotoxicity was assayed by MTT assay. To elucidate the role of glutathione (GSH), the intracellular GSH level was analyzed. The effect of koenimbine in the cell mitochondria was evaluated using mitochondrial membrane potential (MMP) changes. Single cell gel electrophoresis assay was used to examine the level of DNA damage. Heat shock proteins, Hsp 70 and Hsp 90 expressions were checked at mRNA and protein level. Ascorbic acid and catalase were used as control antioxidants. Results. It was observed that koenimbine considerably increased DNA damage in HepG2 cells at subcytotoxic concentrations. Koenimbine induced the increased levels of reactive oxygen species (ROS) and reduction of GSH level in HepG2 cells, together with time-dependent loss of MMP. In addition, results clearly showed that koenimbine encouraged cells to express Hsp 70 and Hsp 90 in a concentration-dependent manner up to a concentration of 100 µM and a time-dependent manner at 24-hour incubation both at transcriptional and translational levels. The antioxidant capacity of ascorbic acid was found to be not as prominent as to catalase throughout the study. Conclusion. Based on these data it can be concluded that koenimbine causes DNA strand breaks in HepG2 cells, probably through oxidative stress. Moreover, the oxidative stress induced was closely associated with MMP reduction and GSH depletion associated with HSP modulation at subcytotoxic concentration. PMID:27879375

  6. Active Fragment of Veronica ciliata Fisch. Attenuates t-BHP-Induced Oxidative Stress Injury in HepG2 Cells through Antioxidant and Antiapoptosis Activities

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    Yiran Sun

    2017-01-01

    Full Text Available Excessive amounts of reactive oxygen species (ROS in the body are a key factor in the development of hepatopathies such as hepatitis. The aim of this study was to assess the antioxidation effect in vitro and hepatoprotective activity of the active fragment of Veronica ciliata Fisch. (VCAF. Antioxidant assays (DPPH, superoxide, and hydroxyl radicals scavenging were conducted, and hepatoprotective effects through the application of tert-butyl hydroperoxide- (t-BHP- induced oxidative stress injury in HepG2 cells were evaluated. VCAF had high phenolic and flavonoid contents and strong antioxidant activity. From the perspective of hepatoprotection, VCAF exhibited a significant protective effect on t-BHP-induced HepG2 cell injury, as indicated by reductions in cytotoxicity and the levels of ROS, 8-hydroxydeoxyguanosine (8-OHdG, and protein carbonyls. Further study demonstrated that VCAF attenuated the apoptosis of t-BHP-treated HepG2 cells by suppressing the activation of caspase-3 and caspase-8. Moreover, it significantly decreased the levels of ALT and AST, increased the activities of acetyl cholinesterase (AChE, glutathione (GSH, superoxide dismutase (SOD, and catalase (CAT, and increased total antioxidative capability (T-AOC. Collectively, we concluded that VCAF may be a considerable candidate for protecting against liver injury owing to its excellent antioxidant and antiapoptosis properties.

  7. Juglanthraquinone C, a novel natural compound derived from Juglans mandshurica Maxim, induces S phase arrest and apoptosis in HepG2 cells.

    Science.gov (United States)

    Yao, Yao; Zhang, Yu-Wei; Sun, Lu-Guo; Liu, Biao; Bao, Yong-Li; Lin, Hua; Zhang, Yu; Zheng, Li-Hua; Sun, Ying; Yu, Chun-Lei; Wu, Yin; Wang, Guan-Nan; Li, Yu-Xin

    2012-08-01

    Juglanthraquinone C (1,5-dihydroxy-9,10-anthraquinone-3-carboxylic acid, JC), a naturally occurring anthraquinone isolated from the stem bark of Juglans mandshurica, shows strong cytotoxicity in various human cancer cells in vitro. Here, we first performed a structure-activity relationship study of six anthraquinone compounds (JC, rhein, emodin, aloe-emodin, physcion and chrysophanol) to exploit the relationship between their structural features and activity. The results showed that JC exhibited the strongest cytotoxicity of all compounds evaluated. Next, we used JC to treat several human cancer cell lines and found that JC showed an inhibitory effect on cell viability in dose-dependent (2.5-10 μg/ml JC) and time-dependent (24-48 h) manners. Importantly, the inhibitory effect of JC on HepG2 (human hepatocellular carcinoma) cells was more significant as shown by an IC(50) value of 9 ± 1.4 μg/ml, and 36 ± 1.2 μg/ml in L02 (human normal liver) cells. Further study suggested that JC-induced inhibition HepG2 cell proliferation was associated with S phase arrest, decreased protein expression of proliferation marker Ki67, cyclin A and cyclin-dependent kinase (CDK) 2, and increased expression of cyclin E and CDK inhibitory protein Cip1/p21. In addition, JC significantly triggered apoptosis in HepG2 cells, which was characterized by increased chromatin condensation and DNA fragmentation, activation of caspase-9 and -3, and induction of a higher Bax/Bcl2 ratio. Collectively, our study demonstrated that JC can efficiently inhibit proliferation and induce apoptosis in HepG2 cells.

  8. Realgar quantum dots induce apoptosis and necrosis in HepG2 cells through endoplasmic reticulum stress.

    Science.gov (United States)

    Qin, Y U; Wang, Huan; Liu, Zheng-Yun; Liu, Jie; Wu, Jin-Zhu

    2015-09-01

    Realgar (As 4 S 4 ) has been used in traditional Chinese medicines for treatment of malignancies. However, the poor water solubility of realgar limits its clinical application. To overcome this problem, realgar quantum dots (RQDs; 5.48±1.09 nm) were prepared by a photoluminescence method. The mean particle size was characterized by high-resolution transmission electron microscopy and scanning electron microscopy. Our recent studies revealed that the RQDs were effective against tumor growth in tumor-bearing mice without producing apparent toxicity. The present study investigated their anticancer effects and mechanisms in human hepatocellular carcinoma (HepG2) cells. The HepG2 cells and human normal liver (L02) cells were used to determine the cytotoxicity of RQDs. The portion of apoptotic and dead cells were measured by flow cytometry with Annexin V-fluorescein isothiocyanate/propidium iodide double staining. Apoptosis-related proteins and genes were examined by western blot analysis and reverse transcription-quantitative polymerase chain reaction, and the mitochondrial membrane potential was assayed by confocal microscope with JC-1 as a probe. RQDs exhibited cytotoxicity in a concentration-dependent manner and HepG2 cells were more sensitive compared with normal L02 cells. At 15 µg/ml, 20% of the cells were apoptotic, while 60% of the cells were necrotic at 30 µg/ml. The anti-apoptosis protein Bcl-2 was dose-dependently decreased, while pro-apoptotic protein Bax was increased. There was a loss of mitochondrial membrane potential and expression of the stress genes C/EBP-homologous protein 10 and glucose-regulated protein 78 was increased by RQDs. RQDs were effective in the inhibition of HepG2 cell proliferation and this effect was due to induction of apoptosis and necrosis through endoplasmic reticulum stress.

  9. Differential effect of manool--a diterpene from Salvia officinalis, on genotoxicity induced by methyl methanesulfonate in V79 and HepG2 cells.

    Science.gov (United States)

    Nicolella, Heloiza Diniz; de Oliveira, Pollyanna Francielli; Munari, Carla Carolina; Costa, Gizela Faleiros Dias; Moreira, Monique Rodrigues; Veneziani, Rodrigo Cassio Sola; Tavares, Denise Crispim

    2014-10-01

    Salvia officinalis (sage) is a perennial woody subshrub native to the Mediterranean region that is commonly used as a condiment and as an anti-inflammatory, antioxidant and antimicrobial agent due to its biological activities. Manool is the most abundant micro-metabolite found in Salvia officinalis essential oils and extracts. We therefore decided to evaluate the cytotoxic, genotoxic and antigenotoxic potential of manool in Chinese hamster lung fibroblasts (V79) and human hepatoma cells (HepG2). Cytotoxicity was assessed by the colony-forming assay in V79 cells and toxic effects were observed at concentrations of up to 8.0 μg/mL. The micronucleus test was used to evaluate the genotoxicity and antigenotoxicity of manool in V79 and HepG2 cells at concentrations of 0.5-6.0 μg/mL and 0.5-8.0 μg/mL, respectively. For evaluation of antigenotoxicity, the concentrations of manool were combined with methyl methanesulfonate (MMS, 44 μg/mL). The results showed a significant increase in the frequency of micronuclei in cultures of both cell lines treated with the highest concentration tested, demonstrating a genotoxic effect. On the other hand, manool exhibited a protective effect against chromosome damage induced by MMS in HepG2 cells, but not in V79 cells. These data suggest that some manool metabolite may be responsible for the antigenotoxic effect observed in HepG2 cells. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Potassium dichromate induced cytotoxicity, genotoxicity and oxidative stress in human liver carcinoma (HepG2) cells.

    Science.gov (United States)

    Patlolla, Anita K; Barnes, Constance; Hackett, Diahanna; Tchounwou, Paul B

    2009-02-01

    Chromium is a widespread industrial waste. The soluble hexavalent chromium Cr (VI) is an environmental contaminant widely recognized to act as a carcinogen, mutagen and teratogen towards humans and animals. The fate of chromium in the environment is dependent on its oxidation state. Hexavalent chromium primarily enters the cells and undergoes metabolic reduction to trivalent chromium, resulting in the formation of reactive oxygen species together with oxidative tissue damage and a cascade of cellular events. However, the results from in vitro studies are often conflicting. The aim of this study was to develop a model to establish relationships between cytotoxicity, genotoxicity and oxidative stress, in human liver carcinoma [HepG2] cells exposed to potassium dichromate. HepG2 cells were cultured following standard protocols and exposed to various concentrations [0-50 microM] of potassium dichromate [K2Cr2O7]. Following exposure to the toxic metal, the MTT assay was performed to assess the cytotoxicity, the thiobarbituric acid test to evaluate the degree of lipid peroxidation as an indicator of oxidative stress and the alkaline comet assay was used to assess DNA damage to study genotoxicity. The results of the study indicated that potassium dichromate was cytotoxic to HepG2 cells. The LD(50) values of 8.83 +/- 0.89 microg/ml, 6.76 +/- 0.99 microg/ml, respectively, for cell mortality at 24 and 48 hrs were observed, indicating a dose- and time-dependent response with regard to the cytotoxic effects of potassium dichromate. A statistically significant increase in the concentration of malondialdehyde [MDA], an indicator of lipid peroxidation, was recorded in exposed cells [15.9 - 69.9 microM] compared to control [13 microM]. Similarly, a strong dose-response relationship (pDNA damage (comet assay) in HepG2 cells exposed [3.16 +/- 0.70 - 24.84 +/- 1.86 microns - mean comet tail length]; [12.4 +/- 1.45% - 76 +/- 1.49%-% tail DNA] to potassium dichromate than control [3.07 +/- 0.26 microns--mean comet tail length]; [2.69 + 0.19%-% Tail DNA], respectively. The results demonstrated that potassium dichromate was highly cytotoxic to HepG2 cells, and its cytotoxicity seems to be mediated by oxidative stress and DNA damage.

  11. Eicosapentaenoic acid (EPA) induced apoptosis in HepG2 cells through ROS–Ca{sup 2+}–JNK mitochondrial pathways

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yuanyuan; Han, Lirong [Key Laboratory of Food Nutrition and Safety, Ministry of Education, College of Food Engineering and Biotechnology, Tianjin University of Science and Technology, No. 29, 13th Avenue, Tianjin Economy Technological Development Area, Tianjin 300457 (China); Qi, Wentao [Academy of State Administration of Grain, No.11 Baiwanzhuang Avenue, Xicheng District, Beijing, 100037 (China); Cheng, Dai; Ma, Xiaolei; Hou, Lihua [Key Laboratory of Food Nutrition and Safety, Ministry of Education, College of Food Engineering and Biotechnology, Tianjin University of Science and Technology, No. 29, 13th Avenue, Tianjin Economy Technological Development Area, Tianjin 300457 (China); Cao, Xiaohong, E-mail: caoxh@tust.edu.cn [Key Laboratory of Food Nutrition and Safety, Ministry of Education, College of Food Engineering and Biotechnology, Tianjin University of Science and Technology, No. 29, 13th Avenue, Tianjin Economy Technological Development Area, Tianjin 300457 (China); Wang, Chunling, E-mail: wangchunling@tust.edu.cn [Key Laboratory of Food Nutrition and Safety, Ministry of Education, College of Food Engineering and Biotechnology, Tianjin University of Science and Technology, No. 29, 13th Avenue, Tianjin Economy Technological Development Area, Tianjin 300457 (China)

    2015-01-24

    Highlights: • EPA evoked ROS formation, [Ca{sup 2+}]{sub c} accumulation, the opening of MPTP and the phosphorylation of JNK. • EPA-induced [Ca{sup 2+}]{sub c} elevation was depended on production of ROS. • EPA-induced ROS generation, [Ca{sup 2+}]{sub c} increase, and JNK activated caused MPTP opening. • The apoptosis induced by EPA was related to release of cytochrome C through the MPTP. • EPA induced HepG2 cells apoptosis through ROS–Ca{sup 2+}–JNK mitochondrial pathways. - Abstract: Eicosapentaenoic acid (EPA), a well-known dietary n−3 PUFAS, has been considered to inhibit proliferation of tumor cells. However, the molecular mechanism related to EPA-induced liver cancer cells apoptosis has not been reported. In this study, we investigated the effect of EPA on HepG2 cells proliferation and apoptosis mechanism through mitochondrial pathways. EPA inhibited proliferation of HepG2 cells in a dose-dependent manner and had no significant effect on the cell viability of humor normal liver L-02 cells. It was found that EPA initially evoked ROS formation, leading to [Ca{sup 2+}]{sub c} accumulation and the mitochondrial permeability transition pore (MPTP) opening; EPA-induced HepG2 cells apoptosis was inhibited by N-acetylcysteine (NAC, an inhibitor of ROS), 1,2-bis (2-aminophenoxy) ethane-N,N,N′,N′-tetraacetic acid (BAPTA-AM, a chelator of calcium) and CsA (inhibitor of MPTP). The relationship between ROS production, the increase of cytoplasmic Ca and MPTP opening was detected. It seems that ROS may act as an upstream regulator of EPA-induced [Ca{sup 2+}]{sub c} generation, moreover, generation of ROS, overload of mitochondrial [Ca{sup 2+}]{sub c}, and JNK activated cause the opening of MPTP. Western blotting results showed that EPA elevated the phosphorylation status of JNK, processes associated with the ROS generation. Simultaneously, the apoptosis induced by EPA was related to release of cytochrome C from mitochondria to cytoplasm through the MPTP

  12. 8-Methoxypsoralen Induces Intrinsic Apoptosis in HepG2 Cells: Involvement of Reactive Oxygen Species Generation and ERK1/2 Pathway Inhibition

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    Huan Yang

    2015-08-01

    Full Text Available Background/Aims: 8-Methoxypsoralen (8-MOP, a formerly considered photosensitizing agent, induces apoptosis when used alone. On this basis, the present study was designed to explore the effects and mechanisms of 8-MOP-induced apoptosis in human hepatocellular carcinoma HepG2 cells, independent of its photoactivation. Methods: We analyzed the cell viability with MTT assay. Flow cytometry was used to examine the apoptosis rate, mitochondrial membrane potential (MMP and reactive oxygen species (ROS generation after specific staining. The expression and location of apoptosis-associated protein as well as the activation status of cell signaling pathway were determined by Western blot analysis. Results: 8-MOP significantly decreased cell viability and induced cell apoptosis through mitochondrial apoptotic pathway, as demonstrated by increased Bax/Bcl-2 ratio, collapsed MMP, and induced cytochrome c release (Cyt c and apoptosis-inducing factor (AIF transposition. ROS generation was significantly increased by 8-MOP and the eradication of ROS significantly abolished 8-MOP-induced apoptosis. In addition, the activation of ERK1/2 was drastically decreased by 8-MOP as ERK inhibitor PD98059, indicating a role of ERK1/2 signaling pathway in 8-MOP-induced cell apoptosis. Conclusion: 8-MOP induces intrinsic apoptosis by increasing ROS generation and inhibiting ERK1/2 pathway in HepG2 cells. The findings are important in substantiating the anti-tumor role of 8-MOP in cancer therapy.

  13. Spica prunellae and its marker compound rosmarinic acid induced the expression of efflux transporters through activation of Nrf2-mediated signaling pathway in HepG2 cells.

    Science.gov (United States)

    Wu, Jinjun; Zhu, Yuanfeng; Li, Fangyuan; Zhang, Guiyu; Shi, Jian; Ou, Rilan; Tong, Yunli; Liu, Yuting; Liu, Liang; Lu, Linlin; Liu, Zhongqiu

    2016-12-04

    Spica prunellae (SP) is a well-known traditional Chinese medicinal herb with properties of antihypertensive, antihyperglycemic, antiviral, anti-inflammatory, and antitumor activities. This herb is also popularly consumed as a food additive in some drinks or other food forms for treating pyreticosis. Rosmarinic acid (RA) is the marker compound from SP, which possesses anti-oxidative and anti-inflammatory functions. This study aims to investigate the regulatory effect of the water extract of SP (WESP) and RA on efflux transports (ETs), including P-glycoprotein (p-gp), multidrug resistance-associated protein 2 (MRP2), and breast cancer resistance protein (BCRP) in HepG2 cell line. Results would provide beneficial information for the proper application of SP in clinics. HepG2 cells were treated with different doses of the tested drugs for 24 or 96h. MTT assay was used to examine cell viability. The protein and mRNA levels of the ETs were measured by using Western blot and real-time PCR, respectively. Reporter assay was used to study the antioxidant response element (ARE)-luciferin activity by using HepG2-C8 cells, which were generated by transfecting plasmid containing ARE-luciferin gene into HepG2 cells. The transport activities of ETs were tested by using substrate probes. WESP significantly (p<0.05) increased the expression of ETs in a dose-dependent manner. The increase caused by WESP was stronger than RA alone. Both WESP and RA promoted the translocation of nuclear factor E2-related factor-2 (Nrf2) from cytoplasm to the nucleus as well as significantly (p<0.05) enhanced the ARE-luciferin activity. WESP and RA also enhanced the efflux activity of P-gp and MRP2, accompanied by marked increase (p<0.05) in the intracellular ATP levels. WESP could significantly induce the expression of ETs through the activation of Nrf2-mediated signaling pathway in HepG2 cells. RA could be one of the active compounds responsible for the induction. WESP and RA also enhanced the efflux

  14. Involvement of the multidrug resistance P-glycoprotein in acetaminophen-induced toxicity in hepatoma-derived HepG2 and Hep3B cells.

    Science.gov (United States)

    Manov, Irena; Bashenko, Yulia; Hirsh, Mark; Iancu, Theodore C

    2006-09-01

    Acetaminophen overdose causes severe hepatic failure. Although the mechanisms of acetaminophen hepatotoxicity have been well investigated, little is known about the involvement of the P-glycoprotein in acetaminophen transport and toxicity. P-Glycoprotein is a membrane efflux pump, playing a significant role in regulating absorption, excretion, and tissue distribution of many drugs. To evaluate the contribution of P-glycoprotein transporter in the course of acetaminophen-induced toxicity, HepG2 and Hep3B cells with different P-glycoprotein expression and activity, were treated by acetaminophen (1-10 mM) for different time periods, with or without the P-glycoprotein inhibitor verapamil. P-Glycoprotein activity was determined by rhodamine 123 efflux assay and western blot analysis. To assess the acetaminophen-induced toxicity and effect of verapamil, we investigated cellular redox status, phosphatidylserine externalization, nuclear fragmentation and ultrastructural changes. Verapamil markedly enhanced acetaminophen-induced oxidative damage and cell death. Moreover, verapamil revealed acetaminophen toxicity even at subtoxic levels. High acetaminophen concentrations increased P-glycoprotein activity and content in both HepG2 and Hep3B cells. These observations suggest the involvement of P-glycoprotein in acetaminophen transport. Notwithstanding the differences of the investigated hepatoma cell lines in P-glycoprotein function, acetaminophen-induced toxicity was similar, possibly due to different functions of drug-metabolizing systems. We conclude that acetaminophen is a P-glycoprotein substrate and P-glycoprotein is involved in acetaminophen transport and toxicity in HepG2 and Hep3B cells. This study establishes the fact that acetaminophen can modulate P-glycoprotein in tumour cells, suggesting that its routine use in cancer patients in combination with anticancer drugs, may influence the result of chemotherapy.

  15. Lupin peptides lower low-density lipoprotein (LDL) cholesterol through an up-regulation of the LDL receptor/sterol regulatory element binding protein 2 (SREBP2) pathway at HepG2 cell line.

    Science.gov (United States)

    Lammi, Carmen; Zanoni, Chiara; Scigliuolo, Graziana M; D'Amato, Alfonsina; Arnoldi, Anna

    2014-07-23

    Previous experiments in suitable animal models and in mild hypercholesterolemic individuals have shown that the consumption of lupin proteins may be useful for controlling total and low-density lipoprotein (LDL) cholesterol levels. With the objective of providing evidence that peptides deriving from the hydrolysis of lupin proteins may be responsible of the observed activities and for investigating the mechanism of action, HepG2 cells were treated with lupin peptides obtained by either pepsin (P) or trypsin (T) hydrolysis, and molecular and functional investigations were performed on the LDL receptor/SREBP2 pathway. For the first time, this paper provides experimental evidence that lupin peptides are able to interfere with the HMGCoAR activity, up-regulating the LDL receptor (136 and 84% vs the control for P and T peptides, respectively, at 1 mg/mL) and SREBP2 proteins (148 and 73% vs the control for P and T peptides, respectively, at 1 mg/mL) via the activation of PI3K/Akt/GSK3β pathways and increasing the LDL uptake at HepG2 cell line (40 and 50% vs the control for P and T peptides, respectively, at 1 mg/mL). These results may be useful in explaining the activities observed in vivo in animals and humans treated with lupin protein.

  16. Amygdalin isolated from Semen Persicae (Tao Ren) extracts induces the expression of follistatin in HepG2 and C2C12 cell lines.

    Science.gov (United States)

    Yang, Chuanbin; Li, Xuechen; Rong, Jianhui

    2014-01-01

    The Chinese medicine formulation ISF-1 (also known as Bu-Yang-Huan-Wu-Tang) for post-stroke rehabilitation could increase the expression of growth-regulating protein follistatin by approximately 4-fold. This study aims to identify the active compounds of ISF-1 for the induction of follistatin expression. Active compounds in ISF-1 responsible for induction of follistatin were identified by a bioactivity-guided fractionation procedure involving liquid-liquid extraction, HPLC separation and RT-PCR detection. The aqueous extracts of seven ISF-1 ingredients including Semen Persicae (Tao Ren) and the S. Persicae-derived fractions were assayed for the induction of follistatin mRNA expression in human hepatocarcinoma HepG2 cells by RT-PCR. The concentrations of isolated compounds were proportionally normalized to the reported IC50 concentration (5.8 mg/mL) of the formulation ISF-1 in HepG2. The active fractions were characterized by reverse-phase HPLC on a C18 column and identified by mass spectrometry. Three ingredients of ISF-1, namely S. Persicae (Tao Ren), Pheretima (Di Long), and Flos Carthami (Hong Hua), induced the expression of follistatin mRNA. Among these, the ingredient S. Persicae were the most active, and amygdalin from S. Persicae extract was identified as a novel follistatin inducer. Amygdalin stimulated the growth of skeletal muscle cell line C2C12 cells in a concentration-dependent manner. Amygdalin isolated from S. Persicae extract in ISF-1 through a bioactivity-guided fractionation procedure induced the expression of follistatin in HepG2 and C2C12 cell lines.

  17. Ethylacetate extract from Tetrastigma hemsleyanum induces apoptosis via the mitochondrial caspase-dependent intrinsic pathway in HepG2 cells.

    Science.gov (United States)

    Peng, Xin; Zhang, Yuan-Yuan; Wang, Jin; Ji, Qingyong

    2016-01-01

    Ethylacetate extract of Tetrastigma hemsleyanum (EET) has a potent antitumor activity in vitro and in vivo. However, the molecular mechanism underlying EET-induced apoptosis remains elusive. As part of our continuing studies, we investigated the apoptosis mechanism of HepG2 cells exposed to different concentrations of EET in vitro. Confocal laser scanning was used to detect the apoptotic morphological changes. Flow cytometer and inverted fluorescence microscope were used to detect the mitochondrial membrane potential and cytosolic Ca(2+) level. Western blotting analysis was used to evaluate the expression of the apoptosis-related proteins. Annexin V/PI staining was used to investigate cell apoptosis. Spectrophotometry was used to detect the activity of caspase family. The results showed that distinct apoptotic morphological changes occurred in HepG2 cells treated by EET. EET caused collapse of mitochondrial membrane potential, elevation of cytosolic Ca(2+) level, and evoked release of cytochrome c from mitochondria in a concentration-dependent manner. The apoptosis was accompanied by a significant activation of caspase-3, caspase-9, and the cleavage of poly (ADP-ribose) polymerase, but there was no significant change in either the activity or the expression level of caspase-8. Furthermore, EET-induced apoptosis could be inhibited by caspase-9 inhibitor Z-LEHD-FMK but not by caspase-8 inhibitor Z-IETD-FMK. Taken together, these overall results demonstrated that EET-induced apoptosis of HepG2 cells was mediated by the mitochondrial caspase-dependent intrinsic pathway rather than the death receptor/caspase-8-mediated signaling route.

  18. Chalcones suppress fatty acid-induced lipid accumulation through a LKB1/AMPK signaling pathway in HepG2 cells.

    Science.gov (United States)

    Zhang, Tianshun; Yamamoto, Norio; Ashida, Hitoshi

    2014-06-01

    Excessive lipid accumulation in the liver has been proposed to cause hyperlipidemia, diabetes and fatty liver disease. 4-Hydroxyderricin (4HD), xanthoangelol (XAG), cardamonin (CAR) and flavokawain B (FKB) are chalcones that have exhibited various biological effects against obesity, inflammation, and diabetes; however, little is known about the inhibitory effects of these chalcones on fatty liver disease. In the present study, we investigated the ability of 4HD, XAG, CAR, and FKB to reduce lipid accumulation in hepatocytes. When HepG2 cells were treated with a mixture of fatty acids (FAs; palmitic acid : oleic acid = 1 : 2 ratio), significant lipid accumulation was observed. Under the same experimental conditions, addition of chalcones at 5 μM significantly suppressed the FA-induced lipid accumulation. We found that the expression of sterol regulatory element-binding protein-1 (SREBP-1), a key molecule involved in lipogenesis, was decreased in these chalcone-treated cells. We also found that these chalcones increased the expression of peroxisome proliferator-activated receptor α (PPARα), which is involved in FA oxidation. Moreover, these chalcones increased phosphorylation of AMP-activated protein kinase (AMPK) and liver kinase B1 (LKB1), upstream regulators of SREBP-1 and PPARα. We confirmed that an AMPK inhibitor, compound C, reversed chalcone-induced changes in SREBP-1 and PPARα expression in the HepG2 cells. Collectively, we found that 4HD, XAG, CAR, and XAG attenuated lipid accumulation through activation of the LKB1/AMPK signaling pathway in HepG2 cells.

  19. Fucoidan from Fucus vesiculosus protects against alcohol-induced liver damage by modulating inflammatory mediators in mice and HepG2 cells.

    Science.gov (United States)

    Lim, Jung Dae; Lee, Sung Ryul; Kim, Taeseong; Jang, Seon-A; Kang, Se Chan; Koo, Hyun Jung; Sohn, Eunsoo; Bak, Jong Phil; Namkoong, Seung; Kim, Hyoung Kyu; Song, In Sung; Kim, Nari; Sohn, Eun-Hwa; Han, Jin

    2015-02-16

    Fucoidan is an l-fucose-enriched sulfated polysaccharide isolated from brown algae and marine invertebrates. In this study, we investigated the protective effect of fucoidan from Fucus vesiculosus on alcohol-induced murine liver damage. Liver injury was induced by oral administration of 25% alcohol with or without fucoidan (30 mg/kg or 60 mg/kg) for seven days. Alcohol administration increased serum aspartate aminotransferase and alanine aminotransferase levels, but these increases were suppressed by the treatment of fucoidan. Transforming growth factor beta 1 (TGF-β1), a liver fibrosis-inducing factor, was highly expressed in the alcohol-fed group and human hepatoma HepG2 cell; however, the increase in TGF-β1 expression was reduced following fucoidan administration. Treatment with fucoidan was also found to significantly reduce the production of inflammation-promoting cyclooygenase-2 and nitric oxide, while markedly increasing the expression of the hepatoprotective enzyme, hemeoxygenase-1, on murine liver and HepG2 cells. Taken together, the antifibrotic and anti-inflammatory effects of fucoidan on alcohol-induced liver damage may provide valuable insights into developing new therapeutics or interventions.

  20. Fucoidan from Fucus vesiculosus Protects against Alcohol-Induced Liver Damage by Modulating Inflammatory Mediators in Mice and HepG2 Cells

    Directory of Open Access Journals (Sweden)

    Jung Dae Lim

    2015-02-01

    Full Text Available Fucoidan is an l-fucose-enriched sulfated polysaccharide isolated from brown algae and marine invertebrates. In this study, we investigated the protective effect of fucoidan from Fucus vesiculosus on alcohol-induced murine liver damage. Liver injury was induced by oral administration of 25% alcohol with or without fucoidan (30 mg/kg or 60 mg/kg for seven days. Alcohol administration increased serum aspartate aminotransferase and alanine aminotransferase levels, but these increases were suppressed by the treatment of fucoidan. Transforming growth factor beta 1 (TGF-β1, a liver fibrosis-inducing factor, was highly expressed in the alcohol-fed group and human hepatoma HepG2 cell; however, the increase in TGF-β1 expression was reduced following fucoidan administration. Treatment with fucoidan was also found to significantly reduce the production of inflammation-promoting cyclooygenase-2 and nitric oxide, while markedly increasing the expression of the hepatoprotective enzyme, hemeoxygenase-1, on murine liver and HepG2 cells. Taken together, the antifibrotic and anti-inflammatory effects of fucoidan on alcohol-induced liver damage may provide valuable insights into developing new therapeutics or interventions.

  1. Mitochondrial aquaporin-8 knockdown in human hepatoma HepG2 cells causes ROS-induced mitochondrial depolarization and loss of viability

    Energy Technology Data Exchange (ETDEWEB)

    Marchissio, Maria Julia; Francés, Daniel Eleazar Antonio; Carnovale, Cristina Ester; Marinelli, Raúl Alberto, E-mail: rmarinel@unr.edu.ar

    2012-10-15

    Human aquaporin-8 (AQP8) channels facilitate the diffusional transport of H{sub 2}O{sub 2} across membranes. Since AQP8 is expressed in hepatic inner mitochondrial membranes, we studied whether mitochondrial AQP8 (mtAQP8) knockdown in human hepatoma HepG2 cells impairs mitochondrial H{sub 2}O{sub 2} release, which may lead to organelle dysfunction and cell death. We confirmed AQP8 expression in HepG2 inner mitochondrial membranes and found that 72 h after cell transfection with siRNAs targeting two different regions of the human AQP8 molecule, mtAQP8 protein specifically decreased by around 60% (p < 0.05). Studies in isolated mtAQP8-knockdown mitochondria showed that H{sub 2}O{sub 2} release, assessed by Amplex Red, was reduced by about 45% (p < 0.05), an effect not observed in digitonin-permeabilized mitochondria. mtAQP8-knockdown cells showed an increase in mitochondrial ROS, assessed by dichlorodihydrofluorescein diacetate (+ 120%, p < 0.05) and loss of mitochondrial membrane potential (− 80%, p < 0.05), assessed by tetramethylrhodamine-coupled quantitative fluorescence microscopy. The mitochondria-targeted antioxidant MitoTempol prevented ROS accumulation and dissipation of mitochondrial membrane potential. Cyclosporin A, a mitochondrial permeability transition pore blocker, also abolished the mtAQP8 knockdown-induced mitochondrial depolarization. Besides, the loss of viability in mtAQP8 knockdown cells verified by MTT assay, LDH leakage, and trypan blue exclusion test could be prevented by cyclosporin A. Our data on human hepatoma HepG2 cells suggest that mtAQP8 facilitates mitochondrial H{sub 2}O{sub 2} release and that its defective expression causes ROS-induced mitochondrial depolarization via the mitochondrial permeability transition mechanism, and cell death. -- Highlights: ► Aquaporin-8 is expressed in mitochondria of human hepatoma HepG2 cells. ► Aquaporin-8 knockdown impairs mitochondrial H{sub 2}O{sub 2} release and increases ROS. ► Aquaporin

  2. Nanosilica induced dose-dependent cytotoxicity and cell type-dependent multinucleation in HepG2 and L-02 cells

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Yongbo [Capital Medical University, Beijing Key Laboratory for Pediatric Diseases of Otolaryngology, Head and Neck Surgery, Beijing Pediatric Research Institute, Beijing Children’s Hospital (China); Duan, Junchao; Li, Yang; Yu, Yang; Hu, Hejing; Wu, Jing; Zhang, Yannan; Li, Yanbo; CaixiaGuo; Zhou, Xianqing; Sun, Zhiwei, E-mail: zwsun@ccmu.edu.cn [Capital Medical University, School of Public Health (China)

    2016-11-15

    The prevalent exposure to nanosilica gained concerns about health effects of these particles on human beings. Although nanosilica-induced multinucleation has been confirmed previously, the underlying mechanism was still not clear; this study was to investigate the origination of multinucleated cells caused by nanosilica (62 nm) in both HepG2 and L-02 cells. Cell viability and cellular uptake was determined by MTT assay and transmission electron microscope (TEM), respectively. Giemsa staining was applied to detect multinucleation. To clarify the origination of multinucleated cells, fluorescent probes, PKH26 and PKH67, time-lapse observation were further conducted by confocal microscopy. Results indicated that nanosilica particles were internalized into cells and induced cytotoxicity in a dose-dependent manner. Quantification analysis showed that nanosilica significantly increased the rates of binucleated and multinucleated cells, which suggested mitotic catastrophe induction. Moreover, dynamic visualization verified that multinucleation resulted from cell fusion in HepG2 cells not in L-02 cells after nanosilica exposure, suggesting cell type-dependent multinucleation formation. Both multinucleation and cell fusion were involved in genetic instability, which emphasized the significance to explore the multinucleation induced by nanosilica via environmental, occupational and consumer product exposure.

  3. Insulin-induced CARM1 upregulation facilitates hepatocyte proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Yeom, Chul-gon; Kim, Dong-il; Park, Min-jung; Choi, Joo-hee [College of Veterinary Medicine, Chonnam National University, Gwangju 500-757 (Korea, Republic of); Jeong, Jieun; Wi, Anjin; Park, Whoashig [Jeollanamdo Forest Resources Research Institute, Naju 520-833 (Korea, Republic of); Han, Ho-jae [College of Veterinary Medicine, Seoul National University, Seoul 151-741 (Korea, Republic of); Park, Soo-hyun, E-mail: parksh@chonnam.ac.kr [College of Veterinary Medicine, Chonnam National University, Gwangju 500-757 (Korea, Republic of)

    2015-06-05

    Previously, we reported that CARM1 undergoes ubiquitination-dependent degradation in renal podocytes. It was also reported that CARM1 is necessary for fasting-induced hepatic gluconeogenesis. Based on these reports, we hypothesized that treatment with insulin, a hormone typically present under the ‘fed’ condition, would inhibit gluconeogenesis via CARM1 degradation. HepG2 cells, AML-12 cells, and rat primary hepatocytes were treated with insulin to confirm CARM1 downregulation. Surprisingly, insulin treatment increased CARM1 expression in all cell types examined. Furthermore, treatment with insulin increased histone 3 methylation at arginine 17 and 26 in HepG2 cells. To elucidate the role of insulin-induced CARM1 upregulation, the HA-CARM1 plasmid was transfected into HepG2 cells. CARM1 overexpression did not increase the expression of lipogenic proteins generally increased by insulin signaling. Moreover, CARM1 knockdown did not influence insulin sensitivity. Insulin is known to facilitate hepatic proliferation. Like insulin, CARM1 overexpression increased CDK2 and CDK4 expression. In addition, CARM1 knockdown reduced the number of insulin-induced G2/M phase cells. Moreover, GFP-CARM1 overexpression increased the number of G2/M phase cells. Based on these results, we concluded that insulin-induced CARM1 upregulation facilitates hepatocyte proliferation. These observations indicate that CARM1 plays an important role in liver pathophysiology. - Highlights: • Insulin treatment increases CARM1 expression in hepatocytes. • CARM1 overexpression does not increase the expression of lipogenic proteins. • CARM1 knockdown does not influence insulin sensitivity. • Insulin-induced CARM1 upregulation facilitates hepatocyte proliferation.

  4. Dehydroepiandrosterone-induces miR-21 transcription in HepG2 cells through estrogen receptor β and androgen receptor

    Science.gov (United States)

    Teng, Yun; Litchfield, Lacey M.; Ivanova, Margarita M.; Prough, Russell A.; Clark, Barbara J.; Klinge, Carolyn M.

    2014-01-01

    Although oncomiR miR-21 is highly expressed in liver and overexpressed in hepatocellular carcinoma (HCC), its regulation is uncharacterized. We examined the effect of physiologically relevant nanomolar concentrations of dehydroepiandrosterone (DHEA) and DHEA sulfate (DHEA-S) on miR-21 expression in HepG2 human hepatoma cells. 10 nM DHEA and DHEA-S increase pri-miR-21 transcription in HepG2 cells. Dietary DHEA increased miR-21 in vivo in mouse liver. siRNA and inhibitor studies suggest that DHEA-S requires desulfation for activity and that DHEA-induced pri-miR-21 transcription involves metabolism to androgen and estrogen receptor (AR and ER) ligands. Activation of ERβ and AR by DHEA metabolites androst-5-ene-3,17-dione (ADIONE), androst-5-ene-3β,17β-diol (ADIOL), dihydrotestosterone (DHT), and 5α-androstane-3β,17β-diol (3β-Adiol) increased miR-21 transcription. DHEA-induced miR-21 increased cell proliferation and decreased Pdcd4 protein, a bona fide miR-21. Estradiol (E2) inhibited miR-21 expression via ERα. DHEA increased ERβ and AR recruitment to the miR-21 promoter within the VMP1/TMEM49 gene, with possible significance in hepatocellular carcinoma. PMID:24845419

  5. Antioxidant peptides from protein hydrolysate of microalgae Navicula incerta and their protective effects in HepG2/CYP2E1 cells induced by ethanol.

    Science.gov (United States)

    Kang, Kyong-Hwa; Qian, Zhong-Ji; Ryu, BoMi; Karadeniz, Fatih; Kim, Daekyung; Kim, Se-Kwon

    2012-10-01

    Marine microalgae have been reported as valuable new sources of pharmacologically active compounds and there are now numerous commercial applications of microalgae. Hence, in this study we evaluated the protective effects of peptides purified from marine microalgae, Navicula incerta, against alcohol-induced damage in HepG2/CYP2E1 cells. To obtain bioactive peptides from microalgae, N. incerta was hydrolysed using various enzymes (alcalase, α-chymotrypsin, neutrase, papain, pepsin, pronase-E and trypsin), and the hydrolysates were evaluated for cytoprotective activity. Among them, papain-derived hydrolysate exhibited higher antioxidant activities than those of other enzymes. Therefore, papain hydrolysate was purified in order to obtain potent antihepatotoxic and antioxidative peptides. The amino acid sequences of the purified peptides were analysed as; NIPP-1 (Pro-Gly-Trp-Asn-Gln-Trp-Phe-Leu) with molecular mass 1 171 Da, and NIPP-2 (Val-Glu-Val-Leu-Pro-Pro-Ala-Glu-Leu) with molecular mass 1108 Da. Furthermore, this study demonstrated that NIPP-1 and NIPP-2 peptides inhibited ethanol-induced cytotoxicity in HepG2/CYP2E1 cells. Copyright © 2012 John Wiley & Sons, Ltd.

  6. Fusaric Acid Induces DNA Damage and Post-Translational Modifications of p53 in Human Hepatocellular Carcinoma (HepG2 ) Cells.

    Science.gov (United States)

    Ghazi, Terisha; Nagiah, Savania; Tiloke, Charlette; Sheik Abdul, Naeem; Chuturgoon, Anil A

    2017-11-01

    Fusaric acid (FA), a common fungal contaminant of maize, is known to mediate toxicity in plants and animals; however, its mechanism of action is unclear. p53 is a tumor suppressor protein that is activated in response to cellular stress. The function of p53 is regulated by post-translational modifications-ubiquitination, phosphorylation, and acetylation. This study investigated a possible mechanism of FA induced toxicity in the human hepatocellular carcinoma (HepG2 ) cell line. The effect of FA on DNA integrity and post-translational modifications of p53 were investigated. Methods included: (a) culture and treatment of HepG2 cells with FA (IC50 : 580.32 μM, 24 h); (b) comet assay (DNA damage); (c) Western blots (protein expression of p53, MDM2, p-Ser-15-p53, a-K382-p53, a-CBP (K1535)/p300 (K1499), HDAC1 and p-Ser-47-Sirt1); and (d) Hoechst 33342 assay (apoptosis analysis). FA caused DNA damage in HepG2 cells relative to the control (P p53 (0.24-fold, P = 0.0004) and increased the expression of p-Ser-15-p53 (12.74-fold, P = 0.0126) and a-K382-p53 (2.24-fold, P = 0.0096). This occurred despite the significant decrease in the histone acetyltransferase, a-CBP (K1535)/p300 (K1499) (0.42-fold, P = 0.0023) and increase in the histone deacetylase, p-Ser-47-Sirt1 (1.22-fold, P = 0.0020). The expression of MDM2, a negative regulator of p53, was elevated in the FA treatment compared to the control (1.83-fold, P p53 leading to HepG2 cell death. J. Cell. Biochem. 118: 3866-3874, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  7. Salmonella typhimurium strain SL7207 induces apoptosis and inhibits the growth of HepG2 hepatoma cells in vitro and in vivo

    Directory of Open Access Journals (Sweden)

    Baowei Li

    2012-12-01

    Full Text Available Salmonella typhimurium is probably most extensively studied tumor-targeting bacteria and SL7207 is one of its attenuated strains. SL7207 was first made for bacterial vaccine development and its therapeutic efficacy and safety for hepatocellular carcinoma has not been characterized. In this study, the inhibitory ability of SL7207-lux on human hepatoma HepG2 cells was tested in vitro and in vivo. A bacterial luminescent gene cluster (lux CDABE was transfected into SL7207 to better monitor the invasion of the bacteria. The results show that SL7207-lux can rapidly enter HepG2 cells and localize in the cytoplasm. This invasion represses cell proliferation and induces apoptosis. In vivo real-time invasion studies showed that the bacteria gradually accumulate in the tumor. This enrichment was confirmed by anatomic observation at 5 days after inoculation. About 40% of tumor growth was inhibited by SL7207-lux at 34 days post-treatment without significant loss of body weight. The area of necrosis of tumor tissue was clearly increased in the treated group. Bacterial quantification showed that the number of colony-forming units per gram of bacteria within tumor tissue was approximately 1000-fold higher than that of liver and spleen. These data suggest that attenuated S. typhimurium strain SL7207 has potential for the treatment of cancers.

  8. Different effects of three interferons L on Toll-like receptor-related gene expression in HepG2 cells.

    Science.gov (United States)

    Kanda, Tatsuo; Jiang, Xia; Nakamoto, Shingo; Nakamura, Masato; Miyamura, Tatsuo; Wu, Shuang; Yokosuka, Osamu

    2013-11-01

    IFNL1 (IL29), IFNL2 (IL28A) and IFNL3 (IL28B) might play important roles in anti-viral defense. IFNL3 genotypes have been shown to be associated with hepatitis C spontaneous and treatment-induced viral clearance. The effects of IFNL1, IFNL2 and IFNL3 on innate immunity including Toll-like receptor (TLR)-related pathway in human hepatocytes were examined. After G418 screening, we established the human hepatoma stable cell lines HepG2-IL28A, HepG2-IL28B, and HepG2-IL29, expressing IFNL2, IFNL3, and IFNL1 in conditioned medium, respectively, and a control cell line, HepG2-pcDNA3.1. We performed real-time RT-PCR to investigate 84 Toll-like receptor-related gene expressions in triplicate and, using ddCt methods, compared these gene expressions in each cell line. IFNL2, IFNL3 and IFNL1 were respectively detected by ELISA in HepG2-IL28A, HepG2-IL28B and HepG2-IL29. Compared to HepG2-pcDNA3.1 cells, 17 (20.2%), 11 (13.0%) and 16 genes (19.0%) were up-regulated 1.5-fold or more (p<0.05); 10 (11.9%), 2 (2.3%) and 10 genes (11.9%) were 1.5-fold or more down-regulated (p<0.05) in HepG2-IL28A, HepG2-IL28B and HepG2-IL29, respectively. EIF2AK2 and SARM1 were up-regulated among all cells. Of interest, TLR3, TLR4 and related molecules CXCL10 (IP10), IL6, EIF2K2, IFNB1, and IRF1, important genes in the progression of HCV-related pathogenesis and antiviral activities against HCV, in HepG2-IL28B, presented different profiles from those of HepG2-IL28A and HepG2-IL29. IFNL3 induces interferon-stimulated genes (ISGs) that are reportedly associated with the progression of HCV-related pathogenesis and antiviral activities against HCV. IFNL is a powerful modulator of innate immune response and it is supposed that the 3 IFNLs may play different roles in the antiviral activity against HBV and HCV. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Plasmatic concentration of organochlorine lindane acts as metabolic disruptors in HepG2 liver cell line by inducing mitochondrial disorder

    Energy Technology Data Exchange (ETDEWEB)

    Benarbia, Mohammed el Amine [LUNAM Université, Angers (France); Inserm 1063, Angers (France); Macherel, David [LUNAM Université, Angers (France); UMR 1345 IRHS, Angers (France); Faure, Sébastien; Jacques, Caroline; Andriantsitohaina, Ramaroson [LUNAM Université, Angers (France); Inserm 1063, Angers (France); Malthièry, Yves, E-mail: yves.malthiery@univ-angers.fr [LUNAM Université, Angers (France); Inserm 1063, Angers (France)

    2013-10-15

    Lindane (LD) is a persistent environmental pollutant that has been the subject of several toxicological studies. However, concentrations used in most of the reported studies were relatively higher than those found in the blood of the contaminated area residents and effects of low concentrations remain poorly investigated. Moreover, effects on cell metabolism and mitochondrial function of exposure to LD have received little attention. This study was designed to explore the effects of low concentrations of LD on cellular metabolism and mitochondrial function, using the hepatocarcinoma cell line HepG2. Cells were exposed to LD for 24, 48 and 72 h and different parameters linked with mitochondrial regulation and energy metabolism were analyzed. Despite having any impact on cellular viability, exposure to LD at plasmatic concentrations led to an increase of maximal respiratory capacity, complex I activity, intracellular ATP and NO release but decreased uncoupled respiration to ATP synthesis and medium lactate levels. In addition, LD exposure resulted in the upregulation of mitochondrial biogenesis genes. We suggest that, at plasmatic concentrations, LD acts as a metabolic disruptor through impaired mitochondrial function and regulation with an impact on cellular energetic metabolism. In addition, we propose that a cellular assay based on the analysis of mitochondria function, such as described here for LD, may be applicable for larger studies on the effects of low concentrations of xenobiotics, because of the exquisite sensitivity of this organelle. - Highlights: Our data clearly demonstrated in HepG2 cells that exposure at plasmatic low concentrations of LD were able to: • Impair mitochondrial function • Caused alteration on nucleo-mitochondrial cross-talk • Increase nitric oxide release and protein nitration • Impair cellular energetic metabolism and lipid accumulation.

  10. Gomisin J Inhibits Oleic Acid-Induced Hepatic Lipogenesis by Activation of the AMPK-Dependent Pathway and Inhibition of the Hepatokine Fetuin-A in HepG2 Cells.

    Science.gov (United States)

    Kim, Myungsuk; Lim, Sue Ji; Lee, Hee-Ju; Kim, Sun Young; Nho, Chu Won

    2015-11-11

    The aim of our study is to investigate the molecular mechanism of gomisin J from Schisandra chinensis on the oleic acid (OA)-induced lipid accumulation in HepG2 cells. Gomisin J attenuated lipid accumulation in OA-induced HepG2 cells. It also suppressed the expression of lipogenic enzymes and inflammatory mediators and increased the expression of lipolytic enzymes in OA-induced HepG2 cells. Furthermore, the use of specific inhibitors and fetuin-A siRNA and liver kinase B1 (LKB1) siRNA transfected cells demonstrated that gomisin J regulated lipogenesis and lipolysis via inhibition of fetuin-A and activation of an AMP-activated protein kinase (AMPK)-dependent pathway in HepG2 cells. Our results showed that gomisin J suppressed lipid accumulation by regulating the expression of lipogenic and lipolytic enzymes and inflammatory molecules through activation of AMPK, LKB1, and Ca(2+)/calmodulin-dependent protein kinase II and inhibition of fetuin-A in HepG2 cells. This suggested that gomisin J has potential benefits in treating nonalcoholic fatty liver disease.

  11. Protective Effects of Emodin and Chrysophanol Isolated from Marine Fungus Aspergillus sp. on Ethanol-Induced Toxicity in HepG2/CYP2E1 Cells

    Directory of Open Access Journals (Sweden)

    Zhong-Ji Qian

    2011-01-01

    Full Text Available Alcohol-induced liver injury progresses from fatty infiltration followed by a harmful cause of inflammation leading to an irreversible damage. In this study, two compounds (emodin and chrysophanol isolated from marine fungus Aspergillus sp. were examined for their protective effects against ethanol-induced toxicity in vitro. Ethanol-induced HepG2/CYP2E1 cells were treated with the compounds at various concentrations, and the results showed that there was a dose-dependent decrease of gamma-glutamyl transpeptidase (GGT activity and increase of glutathione (GSH in the culture media with an increase in cell viability. Furthermore, the protective effects of the compounds were evaluated by protein expression levels of GGT, GSH, and CYP2E1 using Western blot. Among the compounds, emodin addressed to the ethanol-induced cytotoxicity more effectively compared to the chrysophanol. It could be suggested that emodin isolated from this genus would be a potential candidate for attenuating ethanol induced liver damage for further industrial applications such as functional food and pharmaceutical developments.

  12. Punicalagin attenuates palmitate-induced lipotoxicity in HepG2 cells by activating the Keap1-Nrf2 antioxidant defense system.

    Science.gov (United States)

    Yan, Chunhong; Sun, Wenyan; Wang, Xun; Long, Jiangang; Liu, Xuebo; Feng, Zhihui; Liu, Jiankang

    2016-05-01

    Free fatty acids (FFA) could induce hepatocyte lipotoxicity, which plays an important role in the initiation of nonalcoholic fatty liver disease (NAFLD). Inhibition of FFA-induced lipotoxicity is suggested as a potential treatment for nonalcoholic fatty liver disease. The aim of the current study is to explore the effect of punicalagin, a polyphenol abundant in pomegranate, on FFA-induced hepatic lipotoxicity and its potential mechanisms. HepG2 cells were exposed to 250 μM palmitate for 24 h with or without punicalagin pretreatment. Punicalagin pretreatment attenuated palmitate-induced mitochondrial membrane potential lost, ATP depletion, and reactive oxygen species production. Punicalagin also increased hepatocyte viability by blocking mitochondria-mediated caspase-dependent apoptosis. The hepatoprotective effect was associated with an exaggerated phosphorylation of extracellular signal regulated kinase as well as significant nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear translocation and target genes induction. Blockage of extracellular signal regulated kinase by a pharmacological inhibitor abrogated the cytoprotective effect of punicalagin and its induction of Nrf2 pathway. Knockdown of Nrf2 by specific small interfering RNA also diminished the protective effects of punicalagin, while knockdown of Kelch-like ECH-associated protein 1 (Keap1) with small interfering RNA could promote Nrf2 nuclear translocation and exert similar protection as punicalagin treatment. These findings suggest that punicalagin could effectively attenuate FFA-induced lipotoxicity by activating Keap1-Nrf2 cytoprotective signaling pathway. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Potentiation of LPS-Induced Apoptotic Cell Death in Human Hepatoma HepG2 Cells by Aspirin via ROS and Mitochondrial Dysfunction: Protection by N-Acetyl Cysteine.

    Directory of Open Access Journals (Sweden)

    Haider Raza

    Full Text Available Cytotoxicity and inflammation-associated toxic responses have been observed to be induced by bacterial lipopolysaccharides (LPS in vitro and in vivo respectively. Use of nonsteroidal anti-inflammatory drugs (NSAIDs, such as aspirin, has been reported to be beneficial in inflammation-associated diseases like cancer, diabetes and cardiovascular disorders. Their precise molecular mechanisms, however, are not clearly understood. Our previous studies on aspirin treated HepG2 cells strongly suggest cell cycle arrest and induction of apoptosis associated with mitochondrial dysfunction. In the present study, we have further demonstrated that HepG2 cells treated with LPS alone or in combination with aspirin induces subcellular toxic responses which are accompanied by increase in reactive oxygen species (ROS production, oxidative stress, mitochondrial respiratory dysfunction and apoptosis. The LPS/Aspirin induced toxicity was attenuated by pre-treatment of cells with N-acetyl cysteine (NAC. Alterations in oxidative stress and glutathione-dependent redox-homeostasis were more pronounced in mitochondria compared to extra- mitochondrial cellular compartments. Pre-treatment of HepG2 cells with NAC exhibited a selective protection in redox homeostasis and mitochondrial dysfunction. Our results suggest that the altered redox metabolism, oxidative stress and mitochondrial function in HepG2 cells play a critical role in LPS/aspirin-induced cytotoxicity. These results may help in better understanding the pharmacological, toxicological and therapeutic properties of NSAIDs in cancer cells exposed to bacterial endotoxins.

  14. Effect of Phyllanthus amarus Extract on 5-Fluorouracil-Induced Perturbations in Ribonucleotide and Deoxyribonucleotide Pools in HepG2 Cell Line

    Directory of Open Access Journals (Sweden)

    Jian-Ru Guo

    2016-09-01

    Full Text Available The aim of this study was to investigate the antitumor activities of Phyllanthus amarus (PHA and its potential of herb–drug interactions with 5-Fluorouracil (5-FU. Cell viability, ribonucleotides (RNs and deoxyribonucleotides (dRNs levels, cell cycle distribution, and expression of thymidylate synthase (TS and ribonucleotide reductase (RR proteins were measured with 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay, high performance liquid chromatography tandem mass spectrometry (HPLC/MS/MS method, flow cytometry and Western blot analysis, respectively. Our standardized PHA extract showed toxicity to HepG2 cells at high concentrations after 72 h exposure and induced G2/M cell cycle arrest. Combined use of 5-FU with PHA resulted in significant decreases in ATP, CTP, GTP, UTP and dTTP levels, while AMP, CMP, GMP and dUMP levels increased significantly compared with use of 5-FU alone. Further, PHA could increase the role of cell cycle arrest at S phase induced by 5-FU. Although PHA alone had no direct impact on TS and RR, PHA could change the levels of RNs and dRNs when combined with 5-FU. This may be due to cell cycle arrest or regulation of key enzyme steps in intracellular RNs and dRNs metabolism.

  15. Effects of Salvia officinalis and Thymus vulgaris on oxidant-induced DNA damage and antioxidant status in HepG2 cells.

    Science.gov (United States)

    Kozics, Katarína; Klusová, Veronika; Srančíková, Annamária; Mučaji, Pavol; Slameňová, Darina; Hunáková, Lubica; Kusznierewicz, Barbara; Horváthová, Eva

    2013-12-01

    Salvia officinalis (SO) and Thymus vulgaris (TV) are medicinal plants well known for their curative powers. However, the molecular mechanisms responsible for these abilities of sage and thyme have not been fully understood yet. In this study we investigated the composition and the quantitative estimation of plant extracts, the protective effects of plant extracts against hydrogen peroxide- and 2,3-dimethoxy-1,4-naphthoquinone-induced DNA damage, and levels of enzymatic and non-enzymatic antioxidants (superoxide dismutase, glutathione peroxidase, glutathione) in human HepG2 cells. To measure antioxidative activity of plant extracts we used three assays: 1,1-diphenyl-2-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). The results showed that the oxidant-induced DNA lesions were significantly reduced in cells pre-treated with the plant extracts studied. The observed DNA-protective activity could be explained by both elevation of GPx activity in cells pre-treated with SO and TV and antioxidant activity of SO and TV. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. α-Hispanolol sensitizes hepatocellular carcinoma cells to TRAIL-induced apoptosis via death receptor up-regulation

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    Mota, Alba, E-mail: amota@iib.uam.es [Unidad de Terapias Farmacológicas, Área de Genética Humana, Instituto de Investigación de Enfermedades Raras (IIER), Instituto de Salud Carlos III, Madrid (Spain); Jiménez-Garcia, Lidia, E-mail: ljimenez@isciii.es [Unidad de Terapias Farmacológicas, Área de Genética Humana, Instituto de Investigación de Enfermedades Raras (IIER), Instituto de Salud Carlos III, Madrid (Spain); Herránz, Sandra, E-mail: sherranz@isciii.es [Unidad de Terapias Farmacológicas, Área de Genética Humana, Instituto de Investigación de Enfermedades Raras (IIER), Instituto de Salud Carlos III, Madrid (Spain); Heras, Beatriz de las, E-mail: lasheras@ucm.es [Departamento de Farmacología, Facultad de Farmacia, Universidad Complutense de Madrid (UCM), Madrid (Spain); Hortelano, Sonsoles, E-mail: shortelano@isciii.es [Unidad de Terapias Farmacológicas, Área de Genética Humana, Instituto de Investigación de Enfermedades Raras (IIER), Instituto de Salud Carlos III, Madrid (Spain)

    2015-08-01

    Hispanolone derivatives have been previously described as anti-inflammatory and antitumoral agents. However, their effects on overcoming Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) resistance remain to be elucidated. In this study, we analyzed the cytotoxic effects of the synthetic hispanolone derivative α-hispanolol (α-H) in several tumor cell lines, and we evaluated the induction of apoptosis, as well as the TRAIL-sensitizing potential of α-H in the hepatocellular carcinoma cell line HepG2. Our data show that α-H decreased cell viability in a dose-dependent manner in HeLa, MDA-MB231, U87 and HepG2 cell lines, with a more prominent effect in HepG2 cells. Interestingly, α-H had no effect on non-tumoral cells. α-H induced activation of caspase-8 and caspase-9 and also increased levels of the proapoptotic protein Bax, decreasing antiapoptotic proteins (Bcl-2, X-IAP and IAP-1) in HepG2 cells. Specific inhibition of caspase-8 abrogated the cascade of caspase activation, suggesting that the extrinsic pathway has a critical role in the apoptotic events induced by α-H. Furthermore, combined treatment of α-H with TRAIL enhanced apoptosis in HepG2 cells, activating caspase-8 and caspase-9. This correlated with up-regulation of both the TRAIL death receptor DR4 and DR5. DR4 or DR5 neutralizing antibodies abolished the effect of α-H on TRAIL-induced apoptosis, suggesting that sensitization was mediated through the death receptor pathway. Our results demonstrate that α-H induced apoptosis in the human hepatocellular carcinoma cell line HepG2 through activation of caspases and induction of the death receptor pathway. In addition, we describe a novel function of α-H as a sensitizer on TRAIL-induced apoptotic cell death in HepG2 cells. - Highlights: • α-Hispanolol induced apoptosis in the human hepatocellular carcinoma cell line HepG2. • α-Hispanolol induced activation of caspases and the death receptor pathway. • α-Hispanolol enhanced

  17. Uric Acid Is Associated With Inflammatory Biomarkers and Induces Inflammation Via Activating the NF-κB Signaling Pathway in HepG2 Cells.

    Science.gov (United States)

    Spiga, Rosangela; Marini, Maria Adelaide; Mancuso, Elettra; Di Fatta, Concetta; Fuoco, Anastasia; Perticone, Francesco; Andreozzi, Francesco; Mannino, Gaia Chiara; Sesti, Giorgio

    2017-06-01

    Serum uric acid (UA) has been associated with increased risk of cardiovascular and metabolic diseases. However, the causal mechanisms linking elevated UA levels to cardio-metabolic diseases are still unsettled. One potential explanation for how UA might contribute to cardio-metabolic disease might be its ability to induce systemic inflammation. Herein, we report a positive relationship between serum UA and acute-phase reactants, such as high-sensitivity C-reactive protein, fibrinogen, ferritin, complement C3, and erythrocyte sedimentation rate, in a cohort of 2731 nondiabetic adults. The relationship remains significant after adjustment for several confounders, including age, sex, adiposity, anti-hypertensive treatments or diuretics use. To confirm the existence of a causal relationship, we examined the effect of UA on the expression of inflammatory biomarkers in human hepatoma HepG2 cells and characterized the signaling pathway by which UA acts. We show that UA stimulates the expression of C-reactive protein, fibrinogen, ferritin, and complement C3 in a dose-dependent fashion. The proinflammatory effects of UA were abrogated by benzbromarone, a specific inhibitor of UA transporters. Exposure of cells to UA resulted in activation of the IκB kinase/IκBα/NF-κB signaling pathway that was attenuated by benzbromarone. The effect of UA was completely blocked by the antioxidant N-acetylcysteine. These in vivo and in vitro data suggest that hyperuricemia might induce the expression of hepatic inflammatory molecules by activating the proinflammatory NF-κB signaling cascade. Because inflammation has an important pathogenetic role in metabolic and cardiovascular disease, our study may help understanding the mechanism by which hyperuricemia may contribute to organ damage. © 2017 American Heart Association, Inc.

  18. FOXO3-mediated up-regulation of Bim contributes to rhein-induced cancer cell apoptosis.

    Science.gov (United States)

    Wang, Jiao; Liu, Shu; Yin, Yancun; Li, Mingjin; Wang, Bo; Yang, Li; Jiang, Yangfu

    2015-03-01

    The anthraquinone compound rhein is a natural agent in the traditional Chinese medicine rhubarb. Preclinical studies demonstrate that rhein has anticancer activity. Treatment of a variety of cancer cells with rhein may induce apoptosis. Here, we report that rhein induces atypical unfolded protein response in breast cancer MCF-7 cells and hepatoma HepG2 cells. Rhein induces CHOP expression, eIF2α phosphorylation and caspase cleavage, while it does not induce glucose-regulated protein 78 (GRP78) expression in both MCF-7 and HepG2 cells. Meanwhile, rhein inhibits thapsigargin-induced GRP78 expression and X box-binding protein 1 splicing. In addition, rhein inhibits Akt phosphorylation and stimulates FOXO transactivation activity. Rhein induces Bim expression in MCF-7 and HepG2 cells, which can be abrogated by FOXO3a knockdown. Knockdown of FOXO3a or Bim abrogates rhein-induced caspase cleavage and apoptosis. The chemical chaperone 4-phenylbutyrate acid antagonizes the induction of FOXO activation, Bim expression and caspase cleavage by rhein, indicating that protein misfolding may be involved in triggering these deleterious effects. We conclude that FOXO3a-mediated up-regulation of Bim is a key mechanism underlying rhein-induced cancer cells apoptosis.

  19. Ruthenium Complexes Induce HepG2 Human Hepatocellular Carcinoma Cell Apoptosis and Inhibit Cell Migration and Invasion through Regulation of the Nrf2 Pathway

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    Yiyu Lu

    2016-05-01

    Full Text Available Ruthenium (Ru complexes are currently the focus of substantial interest because of their potential application as chemotherapeutic agents with broad anticancer activities. This study investigated the in vitro and in vivo anticancer activities and mechanisms of two Ru complexes—2,3,7,8,12,13,17,18-Octaethyl-21H,23H-porphine Ru(II carbonyl (Ru1 and 5,10,15,20-Tetraphenyl-21H,23H-porphine Ru(II carbonyl (Ru2—against human hepatocellular carcinoma (HCC cells. These Ru complexes effectively inhibited the cellular growth of three human hepatocellular carcinoma (HCC cells, with IC50 values ranging from 2.7–7.3 μM. In contrast, the complexes exhibited lower toxicity towards L02 human liver normal cells with IC50 values of 20.4 and 24.8 μM, respectively. Moreover, Ru2 significantly inhibited HepG2 cell migration and invasion, and these effects were dose-dependent. The mechanistic studies demonstrated that Ru2 induced HCC cell apoptosis, as evidenced by DNA fragmentation and nuclear condensation, which was predominately triggered via caspase family member activation. Furthermore, HCC cell treatment significantly decreased the expression levels of Nrf2 and its downstream effectors, NAD(PH: quinone oxidoreductase 1 (NQO1 and heme oxygenase 1 (HO1. Ru2 also exhibited potent in vivo anticancer efficacy in a tumor-bearing nude mouse model, as demonstrated by a time- and dose-dependent inhibition on tumor growth. The results demonstrate the therapeutic potential of Ru complexes against HCC via Nrf2 pathway regulation.

  20. HCV core protein-induced down-regulation of microRNA-152 promoted aberrant proliferation by regulating Wnt1 in HepG2 cells.

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    Shifeng Huang

    Full Text Available BACKGROUND: Hepatitis C virus (HCV has been reported to regulate cellular microRNAs (miRNAs. The HCV core protein is considered to be a potential oncoprotein in HCV-related hepatocellular carcinoma (HCV-HCC, but HCV core-regulated miRNAs are largely unknown. Our preliminary experiments revealed significant down-regulation of microRNA-152 (miR-152 by HCV core protein in HepG2 cells. Through target gene prediction softwares, Wnt1 was predicted to be a potential target of miR-152. The present study was initiated to investigate whether miR-152 is aberrantly regulated by the HCV core protein, and involved in the regulation of the aberrant proliferation of HCV-HCC cells. METHODS: MiR-152 levels were examined by stem-loop real-time RT-PCR (SLqRT-PCR. Cell proliferation was analyzed by MTT and colony formation assay. Cell cycle analysis was performed by flow cytometry. Luciferase reporter assay was conducted to confirm miRNA-target association. Wnt1 expression was determined by real-time qPCR and Western blotting. RESULTS: HCV core protein significantly suppressed miR-152 expression, and led to significant Wnt1 up-regulation with a concomitant aberrantly promoted proliferation. Moreover, we validated that miR-152 inhibition promoted, while miR-152 mimics inhibited cell proliferation. Using, qRT-PCR and western blot, Wnt1 was demonstrated to be regulated by miR-152. Luciferase activity assay showed that while miR-152 mimics significantly reduced the luciferase activity by 83.76% (P<0.0001, miR-152 inhibitor showed no effect on luciferase reporter. Most notably, salvage expression of miR-152 after Ad-HCV core infection for 24 h almost totally reversed the proliferation-promoting effect of the HCV core protein, and meanwhile, reduced the expression of both Wnt1 mRNA and protein to basal levels. CONCLUSION: These findings provide important evidence that the reduced miR-152 expression by HCV core protein can indirectly lose an inhibitory effect on Wnt1

  1. Inhibition of SH2-domain-containing inositol 5-phosphatase (SHIP2) ameliorates palmitate induced-apoptosis through regulating Akt/FOXO1 pathway and ROS production in HepG2 cells

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    Gorgani-Firuzjaee, Sattar [Department of Biochemistry, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran (Iran, Islamic Republic of); Adeli, Khosrow [Division of Clinical Biochemistry, The Hospital for Sick Children, University of Toronto, Toronto (Canada); Meshkani, Reza, E-mail: rmeshkani@tums.ac.ir [Department of Biochemistry, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran (Iran, Islamic Republic of)

    2015-08-21

    The serine–threonine kinase Akt regulates proliferation and survival by phosphorylating a network of protein substrates; however, the role of a negative regulator of the Akt pathway, the SH2-domain-containing inositol 5-phosphatase (SHIP2) in apoptosis of the hepatocytes, remains unknown. In the present study, we studied the molecular mechanisms linking SHIP2 expression to apoptosis using overexpression or suppression of SHIP2 gene in HepG2 cells exposed to palmitate (0.5 mM). Overexpression of the dominant negative mutant SHIP2 (SHIP2-DN) significantly reduced palmitate-induced apoptosis in HepG2 cells, as these cells had increased cell viability, decreased apoptotic cell death and reduced the activity of caspase-3, cytochrome c and poly (ADP-ribose) polymerase. Overexpression of the wild-type SHIP2 gene led to a massive apoptosis in HepG2 cells. The protection from palmitate-induced apoptosis by SHIP2 inhibition was accompanied by a decrease in the generation of reactive oxygen species (ROS). In addition, SHIP2 inhibition was accompanied by an increased Akt and FOXO-1 phosphorylation, whereas overexpression of the wild-type SHIP2 gene had the opposite effects. Taken together, these findings suggest that SHIP2 expression level is an important determinant of hepatic lipoapotosis and its inhibition can potentially be a target in treatment of hepatic lipoapoptosis in diabetic patients. - Highlights: • Lipoapoptosis is the major contributor to the development of NAFLD. • The PI3-K/Akt pathway regulates apoptosis in different cells. • The role of negative regulator of this pathway, SHIP2 in lipoapoptosis is unknown. • SHIP2 inhibition significantly reduces palmitate-induced apoptosis in HepG2 cells. • SHIP2 inhibition prevents palmitate induced-apoptosis by regulating Akt/FOXO1 pathway.

  2. Anticancer effects of pyocyanin on HepG2 human hepatoma cells.

    Science.gov (United States)

    Zhao, J; Wu, Y; Alfred, A T; Wei, P; Yang, S

    2014-06-01

    Pyocyanin, a major virulence factor produced by Pseudomonas aeruginosa, displays redox activity and damaging effects on mammalian cells. In this study, we investigated the effects of pyocyanin on the proliferation of HepG2 tumour cells. Interestingly, pyocyanin significantly inhibited cell proliferation and triggered the production of large amounts of reactive oxygen species (ROS), thereby upregulating superoxide dismutase (SOD) and catalase (CAT). Additionally, pyocyanin treatment significantly depleted reduced glutathione (GSH) and decreased the GSH/oxidized GSH (GSSG) ratio. These results supported that pyocyanin-induced cytotoxicity in HepG2 cells was mediated by acute ROS production and subsequent oxidative stress. SA-β-Gal, acridine orange (AO)/ethidium bromide (EB) double staining, caspase-3 measurements and comet assay results revealed that cell death induced by pyocyanin involved DNA damage and activation of caspase-3, accelerating cell senescence and apoptosis. Thus, our data provided insights into the mechanisms underlying pyocyanin-induced cytotoxicity and may lead to better treatment strategies for cancer. Pyocyanin is a redox-active phenazine toxin. Here, we investigated the ability of pyocyanin to inhibit cancer-related phenotypes in HepG2 human hepatoma cells. Our results indicated that pyocyanin accelerated cellular senescence and apoptosis and induced oxidative stress-associated DNA damage in HepG2 cells. The potential anticancer applications of pyocyanin should be investigated further in clinical studies. © 2014 The Society for Applied Microbiology Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  3. Effects of PARP-1 inhibitors AG-014699 and AZD2281 on proliferation and apoptosis of human hepatoma cell line HepG2

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    DU Senrong

    2015-06-01

    Full Text Available ObjectiveTo observe the inhibitory and pro-apoptotic effects of two poly(ADP-ribose polymerase (PARP-1 inhibitors, AG-014699 and AZD2281, on human hepatoma HepG2 cells and preliminarily explore the mechanism by which AG-014699 induces HepG2 cell apoptosis, and to provide a new therapeutic target for hepatoma. MethodsThe effects of different concentrations of AG-014699 and AZD2281 on HepG2 cell proliferation were determined by MTT assay. The cell apoptosis rate was measured by flow cytometry. The expression levels of caspase-3 and caspase-8 were measured by Western Blot. Inter-group comparison was made by t test. ResultsBoth AG-014699 and AZD2281 suppressed HepG2 cell proliferation in a time- and dose-dependent manner. However, the sensitivity of HepG2 cells to the two PARP-1 inhibitors was different. The half-maximal inhibitory concentrations of AG-014699 and AZD2281 at 48 h determined by MTT assay were about 20 μmol/L and 400 μmol/L, respectively. Flow cytometry and Western blot were not used to evaluate the apoptosis of HepG2 cells exposed to AZD2281 to which these cells were not sensitive. HepG2 cell apoptosis could be induced by 10, 30, and 50 μmol/L AG-014699, and the highest apoptosis rate at 48 h was significantly higher than that of the control group (3100%±2.13% vs 09%±0013%, P<0.01. Compared with those in the control group, the protein levels of caspase-3 and caspase-8 in HepG2 cells after 48-h exposure to 30, and 50 μmol/L AG-014699 increased. ConclusionThe two PARP-1 inhibitors AG-014699 and AZD2281 can inhibit the proliferation of HepG2 cells, which showed different sensitivities to the two inhibitors. AG-014699 can induce HepG2 cell apoptosis by up-regulating the protein expression of caspase-3 and caspase-8.

  4. JS-K, a nitric oxide prodrug, induces DNA damage and apoptosis in HBV-positive hepatocellular carcinoma HepG2.2.15 cell.

    Science.gov (United States)

    Liu, Zhengyun; Li, Guangmin; Gou, Ying; Xiao, Dongyan; Luo, Guo; Saavedra, Joseph E; Liu, Jie; Wang, Huan

    2017-08-01

    Hepatocellular carcinoma (HCC) is the most important cause of cancer-related death, and 85% of HCC is caused by chronic HBV infection, the prognosis of patients and the reduction of HBV DNA levels remain unsatisfactory. JS-K, a nitric oxide-releasing diazeniumdiolates, is effective against various tumors, but little is known on its effects on HBV positive HCC. We found that JS-K reduced the expression of HBsAg and HBeAg in HBV-positive HepG2.2.15 cells. This study aimed to further examine anti-tumor effects of JS-K on HepG2.2.15 cells. The MTT assay and colony forming assay were used to study the cell growth inhibition of JS-K; scratch assay and transwell assay were performed to detect cell migration. The cell cycle was detected by flow cytometry. The immunofluorescence, flow cytometry analysis, and western blot were used to study DNA damage and cell apoptosis. JS-K inhibited HepG2.2.15 cell growth in a dose-dependent manner, suppressed cell colony formation and migration, arrested cells gather in the G2 phase. JS-K (1-20μM) increased the expression of DNA damage-associated protein phosphorylation H2AX (γH2AX), phosphorylation of checkpoint kinase 1 (p-Chk1), phosphorylation of checkpoint kinase 2 (p-Chk2), ataxia-telangiectasia mutated (ATM), phosphorylation of ataxia-telangiectasia mutated rad3-related (p-ATR) and apoptotic-associated proteins cleaved caspase-3, cleaved caspase-7, cleaved poly ADP-ribose polymerase (cleaved PARP). The study demonstrated JS-K is effective against HBV-positive HepG2.2.15 cells, the mechanisms are not only related to inhibition of HBsAg and HBeAg secretion, but also related with induction of DNA damage and apoptosis. JS-K is a promising anti-cancer candidate against HBV-positive HCC. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  5. Gymnaster koraiensis and its major components, 3,5-di-O-caffeoylquinic acid and gymnasterkoreayne B, reduce oxidative damage induced by tert-butyl hydroperoxide or acetaminophen in HepG2 cells

    Directory of Open Access Journals (Sweden)

    Eun Hye Jho

    2013-10-01

    Full Text Available We investigated the protective effects of Gymnaster koraiensisagainst oxidative stress-induced hepatic cell damage. We usedtwo different cytotoxicity models, i.e., the administration oftert-butyl hydroperoxide (t-BHP and acetaminophen, in HepG2cells to evaluate the protective effects of G. koraiensis. The ethylacetate (EA fraction of G. koraiensis and its major compound,3,5-di-O-caffeoylquinic acid (DCQA, exerted protective effectsin the t-BHP-induced liver cytotoxicity model. The EA fractionand DCQA ameliorated t-BHP-induced reductions in GSHlevels and exhibited free radical scavenging activity. The EAfraction and DCQA also significantly reduced t-BHP-inducedDNA damage in HepG2 cells. Furthermore, the hexane fractionof G. koraiensis and its major compound, gymnasterkoreayne B(GKB, exerted strong hepatoprotection in the acetaminopheninducedcytotoxicity model. CYP 3A4 enzyme activity wasstrongly inhibited by the extract, hexane fraction, and GKB. Thehexane fraction and GKB ameliorated acetaminophen-inducedreductions in GSH levels and protected against cell death. [BMBReports 2013; 46(10: 513-518

  6. SM22{alpha}-induced activation of p16{sup INK4a}/retinoblastoma pathway promotes cellular senescence caused by a subclinical dose of {gamma}-radiation and doxorubicin in HepG2 cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Rim; Lee, Hee Min; Lee, So Yong; Kim, Eun Jin; Kim, Kug Chan [Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Paik, Sang Gi [Department of Biology, School of Biosciences and Biotechnology, Chungnam National University, Daejeon (Korea, Republic of); Cho, Eun Wie, E-mail: ewcho@kribb.re.kr [Daejeon-KRIBB-FHCRC Cooperation Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon (Korea, Republic of); Kim, In Gyu, E-mail: igkim@kaeri.re.kr [Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2010-09-10

    Research highlights: {yields} SM22{alpha} overexpression in HepG2 cells leads cells to a growth arrest state, and the treatment of a subclinical dose of {gamma}-radiation or doxorubicin promotes cellular senescence. {yields} SM22{alpha} overexpression elevates p16{sup INK4a} followed by pRB activation, but there are no effects on p53/p21{sup WAF1/Cip1} pathway. {yields} SM22{alpha}-induced MT-1G activates p16{sup INK4a}/pRB pathway, which promotes cellular senescence by damaging agents. -- Abstract: Smooth muscle protein 22-alpha (SM22{alpha}) is known as a transformation- and shape change-sensitive actin cross-linking protein found in smooth muscle tissue and fibroblasts; however, its functional role remains uncertain. We reported previously that SM22{alpha} overexpression confers resistance against anti-cancer drugs or radiation via induction of metallothionein (MT) isozymes in HepG2 cells. In this study, we demonstrate that SM22{alpha} overexpression leads cells to a growth arrest state and promotes cellular senescence caused by treatment with a subclinical dose of {gamma}-radiation (0.05 and 0.1 Gy) or doxorubicin (0.01 and 0.05 {mu}g/ml), compared to control cells. Senescence growth arrest is known to be controlled by p53 phosphorylation/p21{sup WAF1/Cip1} induction or p16{sup INK4a}/retinoblastoma protein (pRB) activation. SM22{alpha} overexpression in HepG2 cells elevated p16{sup INK4a} followed by pRB activation, but did not activate the p53/p21{sup WAF1/Cip1} pathway. Moreover, MT-1G, which is induced by SM22{alpha} overexpression, was involved in the activation of the p16{sup INK4a}/pRB pathway, which led to a growth arrest state and promoted cellular senescence caused by damaging agents. Our findings provide the first demonstration that SM22{alpha} modulates cellular senescence caused by damaging agents via regulation of the p16{sup INK4a}/pRB pathway in HepG2 cells and that these effects of SM22{alpha} are partially mediated by MT-1G.

  7. Extracts of Mauritian Carica papaya (var. solo) protect SW872 and HepG2 cells against hydrogen peroxide induced oxidative stress.

    Science.gov (United States)

    Somanah, Jhoti; Bourdon, Emmanuel; Bahorun, Theeshan

    2017-06-01

    In line with literature documenting the pluripotent activities of tropical fruits, this study evaluated the antioxidant effects of Carica papaya fruit extracts at cellular level. Investigations using cellular models of oxidative stress provided complementary evidence of the antioxidant activities of papaya fruit. At 2 mg dry weight ml-1, extracts of seed from ripe and unripe fruit significantly reduced oxidative stress levels within human pre-adipocytes (SW872) and hepatocellular carcinoma cells (HepG2) exposed to hydrogen peroxide (H2O2). Maintenance of mitochondrial viability, reduction of intracellular reactive oxygen species levels and mediation of pro-inflammatory cytokine secretory levels (tumour necrosis factor-α, interleukin-6, monocyte chemoattractant protein-1) were all indicative of its cytoprotective effects against oxidative-inflammation. This work demonstrates that the Mauritian Solo papaya is an important source of natural antioxidants that could be used for the dietary modulation of oxidative stress and inflammation.

  8. Flavokawains A and B from kava (Piper methysticum) activate heat shock and antioxidant responses and protect against hydrogen peroxide-induced cell death in HepG2 hepatocytes.

    Science.gov (United States)

    Pinner, Keanu D; Wales, Christina T K; Gristock, Rachel A; Vo, Hoa T; So, Nadine; Jacobs, Aaron T

    2016-09-01

    Context Flavokawains are secondary metabolites from the kava plant (Piper methysticum Forst. f., Piperaceae) that have anticancer properties and demonstrated oral efficacy in murine cancer models. However, flavokawains also have suspected roles in rare cases of kava-induced hepatotoxicity. Objective To compare the toxicity flavokawains A and B (FKA, FKB) and monitor the resulting transcriptional responses and cellular adaptation in the human hepatocyte cell line, HepG2. Materials and methods HepG2 were treated with 2-100 μM FKA or FKB for 24-48 h. Cellular viability was measured with calcein-AM and changes in signalling and gene expression were monitored by luciferase reporter assay, real-time PCR and Western blot of both total and nuclear protein extracts. To test for subsequent resistance to oxidative stress, cells were pretreated with 50 μM FKA, 10 μM FKB or 10 μM sulphoraphane (SFN) for 24 h, followed by 0.4-2.8 mM H2O2 for 48 h, and then viability was assessed. Results FKA (≤100 μM) was not toxic to HepG2, whereas FKB caused significant cell death (IC50=23.2 ± 0.8 μM). Both flavokawains activated Nrf2, increasing HMOX1 and GCLC expression and enhancing total glutathione levels over 2-fold (p < 0.05). FKA and FKB also activated HSF1, increasing HSPA1A and DNAJA4 expression. Also, flavokawain pretreatment mitigated cell death after a subsequent challenge with H2O2, with FKA being more effective than FKB, and similar to SFN. Conclusions Flavokawains promote an adaptive cellular response that protects hepatocytes against oxidative stress. We propose that FKA has potential as a chemopreventative or chemotherapeutic agent.

  9. Oleanolic Acid Attenuates Insulin Resistance via NF-κB to Regulate the IRS1-GLUT4 Pathway in HepG2 Cells

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    Ming Li

    2015-01-01

    Full Text Available The aim of our study is to elucidate the mechanisms of oleanolic acid (OA on insulin resistance (IR in HepG2 cells. HepG2 cells were induced with FFA as the insulin resistance model and were treated with OA. Then the glucose content and the levels of tumor necrosis factor-α (TNF-α and interleukin-6 (IL-6 were analyzed. Moreover, protein expression of nuclear factor kappa B (NF-κB, insulin receptor substrate 1(IRS1, and glucose transporter 4 (GLUT4 in cells treated with OA were measured by Western blot analysis. Additionally, IRS1 protein expression exposed to OA was detected after using pyrrolidine dithiocarbamate (PDTC.Our results revealed that OA decreased the glucose content in HepG2 cells in vitro. Moreover, OA reduced the levels of TNF-α and IL-6 and upregulated IRS1 and GLUT4 protein expression. Furthermore, OA also reduced NF-κB protein expression in insulin-resistant HepG2 cells. After blocking NF-κB, the expression of IRS1 protein had no obvious changes when treated with OA. OA attenuated insulin resistance and decreased the levels of TNF-α and IL-6. Meanwhile, OA decreased NF-κB protein expression and upregulated IRS1 and GLUT4 protein expression. Therefore, regulating the IRS1-GLUT4 pathway via NF-κB was the underlying mechanism of OA on insulin resistance.

  10. Vildagliptin and its metabolite M20.7 induce the expression of S100A8 and S100A9 in human hepatoma HepG2 and leukemia HL-60 cells.

    Science.gov (United States)

    Asakura, Mitsutoshi; Karaki, Fumika; Fujii, Hideaki; Atsuda, Koichiro; Itoh, Tomoo; Fujiwara, Ryoichi

    2016-10-19

    Vildagliptin is a potent, orally active inhibitor of dipeptidyl peptidase-4 (DPP-4) for the treatment of type 2 diabetes mellitus. It has been reported that vildagliptin can cause hepatic dysfunction in patients. However, the molecular-mechanism of vildagliptin-induced liver dysfunction has not been elucidated. In this study, we employed an expression microarray to determine hepatic genes that were highly regulated by vildagliptin in mice. We found that pro-inflammatory S100 calcium-binding protein (S100) a8 and S100a9 were induced more than 5-fold by vildagliptin in the mouse liver. We further examined the effects of vildagliptin and its major metabolite M20.7 on the mRNA expression levels of S100A8 and S100A9 in human hepatoma HepG2 and leukemia HL-60 cells. In HepG2 cells, vildagliptin, M20.7, and sitagliptin - another DPP-4 inhibitor - induced S100A9 mRNA. In HL-60 cells, in contrast, S100A8 and S100A9 mRNAs were significantly induced by vildagliptin and M20.7, but not by sitagliptin. The release of S100A8/A9 complex in the cell culturing medium was observed in the HL-60 cells treated with vildagliptin and M20.7. Therefore, the parental vildagliptin- and M20.7-induced release of S100A8/A9 complex from immune cells, such as neutrophils, might be a contributing factor of vildagliptin-associated liver dysfunction in humans.

  11. Protective effects of rambutan (Nephelium lappaceum) peel phenolics on H2O2-induced oxidative damages in HepG2 cells and d-galactose-induced aging mice.

    Science.gov (United States)

    Zhuang, Yongliang; Ma, Qingyu; Guo, Yan; Sun, Liping

    2017-10-01

    Rambutan peel phenolic (RPP) extracts were prepared via dynamic separation with macroporous resin. The total phenolic content and individual phenolics in RPP were determined. Results showed that the total phenolic content of RPP was 877.11 mg gallic acid equivalents (GAE)/g extract. The content of geranin (122.18 mg/g extract) was the highest among those of the 39 identified phenolic compounds. RPP protected against oxidative stress in H 2 O 2 -induced HepG2 cells in a dose-response manner. The inhibitory effects of RPP on cell apoptosis might be related to its inhibitory effects on the generation of intracellular reactive oxygen species and increased effects on superoxide dismutase activity. The in vivo anti-aging activity of RPP was evaluated using an aging mice model that was induced by d-galactose (d-gal). The results showed that RPP enhanced the antioxidative status of experimental mice. Moreover, histological analysis indicated that RPP effectively reduced d-gal-induced liver and kidney tissue damage in a dose-dependent manner. Therefore, RPP can be used as a natural antioxidant and anti-aging agent in the pharmaceutical and food industries. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. A novel AMPK activator, WS070117, improves lipid metabolism discords in hamsters and HepG2 cells

    Directory of Open Access Journals (Sweden)

    Hao Linghua

    2011-04-01

    Full Text Available Abstract Background WS070117 is a novel small molecule compound that significantly improves lipid metabolism disorders in high-fat-diet (HFD induced hyperlipidemia in hamsters. Methods and Results We evaluated liver/body weight ratio, liver histology, serum and hepatic lipid content in HFD-fed hamsters treated with WS070117 for 8 weeks. Comparing with HFD fed hamsters, WS070117 (2 mg/kg per day and above reduced serum triglyceride (TAG, total cholesterol (TC, low density lipoprotein cholesterol (LDL-C and hepatic cholesterol and triglyceride contents. Oil Red O staining of liver tissue also showed that WS070117 improved lipid accumulation. We then carried out an experiment in the oleic acid (OLA-induced steatosis model in HepG2 cell to investigate the lipid-lowering effect of WS070117. Oleic acid (0.25 mM markedly induced lipid accumulation in HepG2 cells, but WS070117 (10 μM inhibited cellular lipid accumulation. In OLA-treated HepG2 cells, WS070117 (above 1 μM treatment reduced lipid contents which synthesized from [1-14C] labeled acetic acid. Because WS070117 is an analog of adenosine, we evaluated the effect of WS070117 on AMP-activated protein kinase (AMPK signaling. The results showed that the activation of AMPK in OLA-induced steatosis in HepG2 cells was up-regulated by treatment with 0.1, 1 and 10 μM WS070117. The hepatic cellular AMPK phosphorylation is also up regulated by WS070117 (6 and 18 mg/kg treatment in HFD fed hamsters. Conclusion These new findings identify WS070117 as a novel molecule that regulates lipid metabolism in the hyperlipidemia hamster model. In vitro and in vivo studies suggested that WS070117 may regulate lipid metabolism through stimulating the activation of AMPK and its downstream pathways.

  13. Ethanol extract from Cnidium monnieri (L.) Cusson induces cell cycle arrest and apoptosis via regulation of the p53‑independent pathway in HepG2 and Hep3B hepatocellular carcinoma cells.

    Science.gov (United States)

    Lim, Eun Gyeong; Kim, Guen Tae; Kim, Bo Min; Kim, Eun Ji; Kim, Sang-Yong; Kim, Young Min

    2018-02-01

    Cnidium monnieri (L.) Cusson is a frequently used traditional Chinese medicine that treats gynecological diseases and carbuncles. However, the mechanism of action of C. monnieri remains to be fully elucidated. The present study examined the cell cycle arrest and apoptotic effects resulting from ethanol extract of C. monnieri (CME) in HepG2 (wild‑type p53) and Hep3B (p53‑null) hepatocellular carcinoma cells. An MTT assay was used to confirm the anti‑proliferative effect of CME. The cells were stained with Hoechst 33342 or propidium iodide. It was demonstrated that proliferation of HepG2 cells was suppressed by CME. Cell cycle arrest occurred in the G1 phase following treatment with CME and the number of apoptotic bodies was increased. The expression levels of cell cycle‑associated proteins, including protein kinase B (Akt), glycogen synthase kinase‑3β (GSK‑3β), p53, cyclin E and cyclin‑dependent kinase 2 (CDK2) were determined by western blot analysis. The protein levels of phosphorylated (p)‑Akt, p‑GSK‑3β, p‑MDM2 and cyclin E were decreased, whereas the protein levels of p53, p21 and p‑CDK2 (Thr14/Tyr15) were increased following treatment with CME. Furthermore, treatment or co‑treatment with LY294002 (phosphoinositide‑3‑kinase/Akt inhibitor) or Pifithrin‑α (p53 inhibitor) with CME resulted in CME‑induced G1 arrest which occurred through the p53‑independent signaling pathway in hepatocellular carcinoma cells. In conclusion, CME induces G1 arrest and apoptosis via the Akt/GSK‑3β signaling pathway which is regulated by MDM2‑induced degradation of p21, rather than p53.

  14. Comparative cytotoxicity of dolomite nanoparticles in human larynx HEp2 and liver HepG2 cells.

    Science.gov (United States)

    Ahamed, Maqusood; Alhadlaq, Hisham A; Ahmad, Javed; Siddiqui, Maqsood A; Khan, Shams T; Musarrat, Javed; Al-Khedhairy, Abdulaziz A

    2015-06-01

    Dolomite is a natural mineral of great industrial and commercial importance. With the advent of nanotechnology, natural minerals including dolomite in the form of nanoparticles (NPs) are being utilized in various applications to improve the quality of products. However, safety or toxicity information of dolomite NPs is largely lacking. This study evaluated the cytotoxicity of dolomite NPs in two widely used in vitro cell culture models: human airway epithelial (HEp2) and human liver (HepG2) cells. Concentration-dependent decreased cell viability and damaged cell membrane integrity revealed the cytotoxicity of dolomite NPs. We further observed that dolomite NPs induce oxidative stress in a concentration-dependent manner, as indicated by depletion of glutathione and induction of reactive oxygen species (ROS) and lipid peroxidation. Quantitative real-time PCR data demonstrated that the mRNA level of tumor suppressor gene p53 and apoptotic genes (bax, CASP3 and CASP9) were up-regulated whereas the anti-apoptotic gene bcl-2 was down-regulated in HEp2 and HepG2 cells exposed to dolomite NPs. Moreover, the activity of apoptotic enzymes (caspase-3 and caspase-9) was also higher in both kinds of cells treated with dolomite NPs. It is also worth mentioning that HEp2 cells seem to be marginally more susceptible to dolomite NPs exposure than HepG2 cells. Cytotoxicity induced by dolomite NPs was efficiently prevented by N-acetyl cysteine treatment, which suggests that oxidative stress is primarily responsible for the cytotoxicity of dolomite NPs in both HEp2 and HepG2 cells. Toxicity mechanisms of dolomite NPs warrant further investigations at the in vivo level. Copyright © 2015 John Wiley & Sons, Ltd.

  15. Microarray Analysis of Mercury-Induced Changes in Gene Expression in Human Liver Carcinoma (HepG2 Cells: Importance in Immune Responses

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    Paul B. Tchounwou

    2006-06-01

    Full Text Available Mercury is widely distributed in the biosphere, and its toxic effects have been associated with human death and several ailments that include cardiovascular diseases, anemia, kidney and liver damage, developmental abnormalities, neurobehavioral disorders, autoimmune diseases, and cancers in experimental animals. At the cellular level, mercury has been shown to interact with sulphydryl groups of proteins and enzymes, to damage DNA, and to modulate cell cycle progression and/or apoptosis. However, the underlying molecular mechanisms of mercury toxicity remain to be elucidated. Our laboratory has demonstrated that mercury exposure induces cytotoxicity and apoptosis, modulates cell cycle, and transcriptionally activates specific stress genes in human liver carcinoma cells. The liver is one of the few organs capable of regeneration from injury. Dormant genes in the liver are therefore capable of reactivation. In this research, we hypothesize that mercury-induced hepatotoxicity is associated with the modulation of specific gene expressions in liver cells that can lead to several disease states involving immune system dysfunctions. In testing this hypothesis, we used an Affymetrix oligonucleotide microarray with probe sets complementary to more than 20,000 genes to determine whether patterns of gene expressions differ between controls and mercury (1-3μg/mL treated cells. There was a clear separation in gene expression profiles between controls and mercury-treated cells. Hierarchical cluster analysis identified 2,211 target genes that were affected. One hundred and thirty-eight of these genes were up-regulated, among which forty three were significantly over-expressed (p = 0.001 with greater than a two-fold change, and ninety five genes were moderately over-expressed with an increase of more than one fold (p = 0.004. Two thousand and twentythree genes were down-regulated with only forty five of them reaching a statistically significant decline at

  16. Induction of S phase arrest and apoptosis by ethyl acetate extract from Tetrastigma hemsleyanum in human hepatoma HepG2 cells.

    Science.gov (United States)

    Peng, Xin; Zhuang, Ding-ding; Guo, Qiao-sheng

    2015-04-01

    Tetrastigma hemsleyanum, a rare and endangered medicinal plant, has attracted much attention due to antitumor and immunomodulatory activities. In this study, the effect and mechanism of ethyl acetate extract from T. hemsleyanum (EET) on cell cycle and apoptosis in human hepatoma HepG2 cells were investigated. Twenty-five to 200 μg/mL of EET were found to have the antiproliferation effect toward HepG2 cells determined by MTT assay. The morphology of EET-treated HepG2 cells showed evidence of apoptosis that included blebbing and chromatin condensation, nucleic fragmentation, and so on. The DNA laddering assay confirmed that DNA fragmentation had occurred during late apoptosis. The cell-cycle analysis indicated that EET was able to induce S phase arrest and typical subdiploid peak in a dose- and time-dependent manner. The apoptosis rate of 200 μg/mL treatment for 24 h was 42.24 ± 4.90%. The protein expression of Bax and P53 was increased after treatment, while that of Bcl2 was significantly decreased in a dose-dependent manner, which suggested that a high Bax/Bcl2 ratio and an upregulated P53 might contribute to the pro-apoptotic activity of EET via the mitochondria-dependent pathway. The protein expression of cyclin-dependent kinase 1 (CDK1) was decreased in EET-treated HepG2 cells, suggesting that EET evoked S phase arrest possibly through the downregulation of cyclin A-CDK1 complex. In conclusion, the cytotoxicity on HepG2 cells induced by EET is a result of both cell-cycle arrest and apoptosis. Thus, it may have therapeutic potential for the treatment of liver cancer.

  17. PKCα mediated induction of miR-101 in human hepatoma HepG2 cells

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    Chen Hua-Chien

    2010-05-01

    Full Text Available Abstract Background Protein Kinase C (PKC is a serine/threonine kinase that involved in controlling of many cellular processes such as cell proliferation and differentiation. We have observed previously that TPA (12-O-tetradecanoylphorbol 13-acetate induces cell cycle arrest in G0/G1 phase in human hepatoma HepG2 cells. However, is there any miRNA involved in PKCα mediated cell growth arrest is still unknown. Methods We first surveyed 270 miRNA expression profiles in 20 pairs of human hepatoma tissues. We identified 11 up-regulated and 23 down-regulated miRNAs (FDR = 2 in human hepatoma tissue after Student's T-test and Mann-Whitney rank test. We then examined miRNAs expression profile in TPA treated HepG2 cells. Two miRNAs, miR-101, and miR-29c, were shown to be significantly down regulated in human hepatoma tissues and induced over 4-fold in HepG2 cells under TPA treatment. Results In this study, we examined TPA regulated miRNA expression profile in human hepatoma HepG2 cells. We identified two miRNAs, 101 and 29c, were induced by TPA and down regulated in human hepatoma tissues suggest that they might play as tumor suppressor gene and in tumor formation of HCC. Since induction kinetics of miR-101 by TPA was much faster than miR-29c suggests that the induction of miR-101 may be the primary response of TPA treatment. We then further investigated how miR-101 was regulated by TPA. MiR-101 targets two subunits of PRC2 complex, enhancer of zeste homolog 2 (EZH2 and EED, and was shown to play as a tumor suppressor gene in human prostate, breast and liver cancers. The target sequence of miR-101 located in the 3' UTR of both EZH2 and EED's mRNA was identified by bioinformatic analysis and was validated by reporter luciferase activity assay. Then we showed that TPA not only up regulated miR-101 expression, but also reduced protein level of EZH2, EED and H3K27me3 in HepG2 cells. Using lenti-virus-mediated shRNA to knockdown endogenous PKCα expression

  18. Lentivirus-delivered short hairpin RNA targeting SNAIL inhibits HepG2 cell growth.

    Science.gov (United States)

    Liu, Jing; Jiang, Gang; Liu, Shihai; Liu, Zimin; Pan, Huazheng; Yao, Ruyong; Liang, Jun

    2013-09-01

    Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related mortality worldwide, and the highest incidence rates are reported in East Asia. We previously showed that SNAIL is upregulated in HCC tissues. In the present study, we aimed to investigate RNA interference-mediated targeting of SNAIL on the growth of HepG2 cells. We constructed three RNA interference plasmids targeting the SNAIL gene and selected the most efficient shRNA expression cassette. After the lentivirus (LV)-SNAIL small interfering (si)RNA vector was transfected into the HepG2 cell line, cell proliferation was measured using the MTT assay. E-cadherin mRNA and protein expression levels were examined by quantitative PCR and western blotting, respectively. We successfully constructed an LV-SNAIL siRNA lentiviral vector and demonstrated that it suppressed the expression of the SNAIL gene in HepG2 cells. RNA interference of SNAIL by the LV-SNAIL siRNA construct significantly inhibited the growth of HepG2 cells, in addition to significantly increasing E-cadherin mRNA and protein expression. Our findings strongly suggest that SNAIL and E-cadherin play a significant role in HCC progression, and exhibit a negative correlation. Furthermore, the expression of E-cadherin may be responsible for the reduced proliferation and survival of HepG2 cells. Thus, the SNAIL signaling pathway may provide a novel therapeutic target for the treatment of HCC.

  19. The role of the vascular endothelial growth factor/vascular endothelial growth factor receptors axis mediated angiogenesis in curcumin-loaded nanostructured lipid carriers induced human HepG2 cells apoptosis

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    Fengling Wang

    2015-01-01

    Full Text Available Background: Curcumin (diferuloylmethane, the active constituent of turmeric extract has potent anti-cancer properties have been demonstrated in hepatocellular carcinoma (HCC. However, its underlying molecular mechanism of therapeutic effects remains unclear. Vascular endothelial growth factor (VEGF and its receptors (VEGFRs have crucial roles in tumor angiogenesis. Purpose: The goal of this study was to investigate the role of the VEGF/VEGFRs mediated angiogenesis during the proliferation and apoptosis of human HepG2 hepatoma cell line and the effect of curcumin-loaded nanostructured lipid carriers (Cur-NLC. Materials and Methods: The proliferation of HepG2 cells was determined by methyl thiazolyl tetrazolium after exposure to Cur-NLC and native curcumin. Apoptosis was quantified by flow cytometry with annexin V-fluorescein isothiocyanate and propidium iodide staining. Cellular internalization of Cur-NLC was observed by fluorescent microscope. The level of VEGF was detected by enzyme-linked immunosorbent assay kits. The expression of VEGFRs was quantified by Western blotting. Results: Cur-NLC was more effective in inhibiting the proliferation and enhancing the apoptosis of HepG2 cells than native curcumin. Fluorescent microscope analysis showed that HepG2 cells internalized Cur-NLC more effectively than native curcumin. Furthermore, Cur-NLC down-regulated the level of VEGF and the expression of VEGFR-2, but had a slight effect on VEGFR-1. Conclusion: These results clearly demonstrated that Cur-NLC was more effective in anti-cancer activity than the free form of curcumin. These studies demonstrate for the 1 st time that Cur-NLC exerts an antitumor effect on HepG2 cells by modulating VEGF/VEGFRs signaling pathway.

  20. Ceramide-induced TCR up-regulation

    DEFF Research Database (Denmark)

    Menné, C; Lauritsen, Jens Peter Holst; Dietrich, J

    2000-01-01

    inhibitors indicated that ceramide-induced TCR up-regulation was most probably mediated by serine/threonine protein phosphatase 2A. Analyses of T cell variants demonstrated that TCR up-regulation was dependent on the presence of an intact CD3gamma L-based motif and thus acted on TCR engaged in the recycling......The TCR is a constitutively recycling receptor meaning that a constant fraction of TCR from the plasma membrane is transported inside the cell at the same time as a constant fraction of TCR from the intracellular pool is transported to the plasma membrane. TCR recycling is affected by protein...... kinase C activity. Thus, an increase in protein kinase C activity affects TCR recycling kinetics leading to a new TCR equilibrium with a reduced level of TCR expressed at the T cell surface. Down-regulation of TCR expression compromises T cell activation. Conversely, TCR up-regulation is expected...

  1. Effects of guggulsterone on proliferation and apoptosis of HepG2 human hepatocellular carcinoma cells

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    JIA Xiaoli

    2013-06-01

    Full Text Available ObjectiveTo investigate the potential therapeutic effects of the plant-derived polyphenol, guggulsterone, on cell proliferation and apoptosis of hepatocellular carcinoma (HCC by using an in vitro system with the human hepatoma cell line, HepG2. MethodsHepG2 cells and normal human liver L-02 cells were treated with different concentrations of guggulsterone (5-100 μmol/L for 24-72 hours. Differential effects on cell proliferation were tested by MTT assay and on cell cycle and apoptosis were detected by flow cytometry (FACS. ResultsGuggulsterone significantly inhibited HepG2 cell proliferation in a dose- and time-dependent manner, with the maximal inhibition effect being observed with 100 μmol/L guggulsterone (81.9%±1.92%. FACS analysis indicated that guggulsterone-treated HepG2 cells were arrested in the G0/G1 phase. Guggulsterone also induced apoptosis of HepG2 cells (apoptotic %: 50 μmol/L, 24.91±2.41 and 75 μmol/L, 53.03±2.28. ConclusionGuggulsterone exerts anticancer effects on HepG2 hepatoma cells by inhibiting cell proliferation and inducing apoptosis. The anti-proliferative effect may be related to interference of the cell cycle.

  2. Effects of sargentgloryvine stem extracts on HepG-2 cells in vitro and in vivo

    Science.gov (United States)

    Wang, Ming-Hua; Long, Min; Zhu, Bao-Yi; Yang, Shu-Hui; Ren, Ji-Hong; Zhang, Hui-Zhong

    2011-01-01

    AIM: To observe the effects of sargentgloryvine stem extracts (SSE) on the hepatoma cell line HepG-2 in vitro and in vivo and determine its mechanisms of action. METHODS: Cultured HepG-2 cells treated with SSE were analysed by 3-(4,5-Dimethyl-thiazol-2-yl)-2,5-Diphenyltetrazolium bromide and clone formation assay. The cell cycle and apoptosis analysis were conducted by flow cytometric, TdT-Mediated dUTP Nick End Labeling and acridine orange/ethidium bromide staining methods, and protein expression was examined by both reverse transcriptase-polymerase chain reaction and Western blotting. The pathological changes of the tumor cells were observed by haematoxylin and eosin staining. Tumor growth inhibition and side effects were determined in a xenograft mouse model. RESULTS: SSE treatment could not only inhibit HepG-2 cell proliferation in a dose- and time-dependent manner but also induce apoptosis and cell cycle arrest at the S phase. The number of colonies formed by SSE-treated tumor cells was fewer than that of the controls (P 0.05). Systemic administration of SSE could inhibit the HepG-2 xenograft tumor growth with no obvious toxic side effects on normal tissues. CONCLUSION: SSE can induce apoptosis of HepG-2 cells in vitro and in vivo through decreasing expression of Bcl-xl and Mcl-1 and increasing expression of Bax. PMID:21734793

  3. Radiosensitization to X-ray radiation by telomerase inhibitor MST-312 in human hepatoma HepG2 cells.

    Science.gov (United States)

    Wang, Yali; Sun, Chao; Mao, Aihong; Zhang, Xin; Zhou, Xin; Wang, Zhenhua; Zhang, Hong

    2015-02-15

    Previous studies in malignant cells have shown that irradiation-induced upregulation of telomerase activity, not only protected damaged telomeres, but also contributed to DNA damage repair by chromosomal healing and increased resistance to irradiation. The purpose of the present study was to investigate the radiosensitizing effect of telomerase inhibitor MST-312 and the corresponding mechanism in the human hepatoma cell line HepG2. Cell proliferation, telomerase activity, cell cycle distribution, DNA damage and repair, expression of p53, mitochondrial membrane potential, and cell apoptosis were measured with the MTT assay, real-time fluorescent quantitative PCR, flow cytometry, immunofluorescence, western blots, JC-1 staining, and Hoechst 33258 staining, respectively. MST-312 effectively inhibited telomerase activity and showed relative weak toxicity to HepG2 cells at 4 μM. Compared with irradiation alone, 4 μM MST-312 pretreatment, followed by X-ray treatment, significantly reduced clonogenic potential. Aggravated DNA damage and increased sub-G1 cell fractions were observed. Further investigation found that homologous recombination (HR) repair protein Rad51 foci nuclear formation was blocked, and expression of p53 was elevated. These led to the collapse of mitochondrial membrane potential, and enhanced the apoptotic rate. These data demonstrated that disturbances of telomerase function could enhance the radiosensitivity of HepG2 cells to X-ray irradiation by impairing HR repair processes. In addition, telomerase inhibitor MST-312 may be useful as an adjuvant treatment in combination with irradiation. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Effects of chlorpromazine with and without UV irradiation on gene expression of HepG2 cells

    Energy Technology Data Exchange (ETDEWEB)

    Froetschl, Roland [Federal Institute for Drugs and Medical Devices, Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn (Germany)]. E-mail: r.froetschl@bfarm.de; Weickardt, Sandra [Federal Institute for Drugs and Medical Devices, Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn (Germany); Staszewski, Solveig [Federal Institute for Drugs and Medical Devices, Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn (Germany); Kaufmann, Gabriele [Federal Institute for Drugs and Medical Devices, Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn (Germany); Kasper, Peter [Federal Institute for Drugs and Medical Devices, Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn (Germany)

    2005-08-04

    Damage to DNA can trigger a variety of stress-related signals that alter the expression of genes associated with numerous biological pathways. In this study, we have used a cDNA microarray representing 1089 genes related to DNA damage and repair, cell cycle, transcription, metabolism and other toxicologically important cell functions to identify genes regulated in response to DNA damage in HepG2 cells induced by UV-activated chlorpromazine (CPZ). CPZ itself is not genotoxic but, upon UV irradiation with a non-genotoxic dose in the UVA range, it produces reactive free radical intermediates with DNA damaging properties. Genotoxicity in HepG2 cells was assessed concomitantly to gene expression profiling using the Comet assay. Kinetic studies were performed at a non-cytotoxic but clearly photogenotoxic concentration of CPZ (1.25 {mu}g/ml) to characterize gene expression profiles at four different time points (3, 7, 15, 23 h) post short-term treatment. The results obtained from repeated experiments display a time-dependent expression pattern of up-regulated and repressed genes with distinct peaks in the number of differentially expressed genes at the 7 and 23 h time points. Most of the genes with altered expression belonged to the functional categories of cell cycle regulation and cell proliferation. A comparison with published expression profiles established in response to other genotoxic compounds showed low levels of concordance, which is most likely caused by the fact that extremely different testing conditions were used.

  5. Proteomic analysis of hepatocellular carcinoma HepG2 cells treated with platycodin D.

    Science.gov (United States)

    Lu, Jin-Jian; Lu, De-Zhao; Chen, Yu-Fei; Dong, Ya-Ting; Zhang, Jun-Ren; Li, Ting; Tang, Zheng-Hai; Yang, Zhen

    2015-09-01

    Platycodin D (PD), a triterpenoid saponin isolated from Platycodonis Radix, is a famous Chinese herbal medicine that has been shown to have anti-proliferative effects in several cancer cell lines. The aim of this study was to determine the changes in cellular proteins after the treatment of hepatocellular carcinoma HepG2 cells with PD using proteomics approaches. The cell viability was determined using the MTT assay. The proteome was analyzed by two-dimensional difference gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Western blot analysis was used to confirm the expression of changed proteins. Our results showed that PD inhibited the proliferation of HepG2 cells in concentration- and time-dependent manners. Sixteen proteins were identified to be up-regulated in PD-treated HepG2 cells, including ATP5H, OXCT1, KRT9, CCDC40, ERP29, RCN1, ZNF175, HNRNPH1, HSP27, PA2G4, PHB, BANF1, TPM3, ECH1, LGALS1, and MYL6. Three proteins (i.e., RPS12, EMG1, and KRT1) decreased in HepG2 cells after treatment with PD. The changes in HSP27 and PHB were further confirmed by Western blotting. In conclusion, our results shed new lights on the mechanisms of action for the anti-cancer activity of PD. Copyright © 2015 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

  6. The Mechanism by Which Amentoflavone Improves Insulin Resistance in HepG2 Cells

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    Xiaoke Zheng

    2016-05-01

    Full Text Available Background: The aim of this study was to explore the mechanism by which amentoflavone (AME improves insulin resistance in a human hepatocellular liver carcinoma cell line (HepG2. Methods: A model of insulin resistant cells was established in HepG2 by treatment with high glucose and insulin. The glucose oxidase method was used to detect the glucose consumption in each group. To determine the mechanism by which AME improves insulin resistance in HepG2 cells, enzyme-linked immunosorbent assay (ELISA and western blotting were used to detect the expression of phosphatidyl inositol 3-kinase (PI3K, Akt, and pAkt; the activity of the enzymes involved in glucose metabolism; and the levels of inflammatory cytokines. Results: Insulin resistance was successfully induced in HepG2 cells. After treatment with AME, the glucose consumption increased significantly in HepG2 cells compared with the model group (MG. The expression of PI3K, Akt, and pAkt and the activity of 6-phosphofructokinas (PFK-1, glucokinase (GCK, and pyruvate kinase (PK increased, while the activity of glycogen synthase kinase-3 (GSK-3, phosphoenolpyruvate carboxylase kinase (PEPCK, and glucose-6-phosphatase (G-6-Pase as well as the levels of interleukin-6 (IL-6, interleukin-8 (IL-8, tumor necrosis factor-α (TNF-α, and C reactive protein (CRP decreased. Conclusions: The mechanism by which treatment with AME improves insulin resistance in HepG2 cells may involve the PI3K-Akt signaling pathway, the processes of glucose oxygenolysis, glycogen synthesis, gluconeogenesis and inflammatory cytokine expression.

  7. Cholesterol-lowing effect of taurine in HepG2 cell.

    Science.gov (United States)

    Guo, Junxia; Gao, Ya; Cao, Xuelian; Zhang, Jing; Chen, Wen

    2017-03-16

    A number of studies indicate that taurine promotes cholesterol conversion to bile acids by upregulating CYP7A1 gene expression. Few in vitro studies are concerned the concentration change of cholesterol and its product of bile acids, and the molecular mechanism of CYP7A1 induction by taurine. The levels of intracellular total cholesterol (TC), free cholesterol (FC), cholesterol ester (EC), total bile acids (TBA) and medium TBA were determined after HepG2 cells were cultured for 24/48 h in DMEM supplemented with taurine at the final concentrations of 1/10/20 mM respectively. The protein expressions of CYP7A1, MEK1/2, c-Jun, p-c-Jun and HNF-4α were detected. Taurine significantly reduced cellular TC and FC in dose -and time-dependent ways, and obviously increased intracellular/medium TBA and CYP7A1 expressions. There was no change in c-Jun expression, but the protein expressions of MEK1/2 and p-c-Jun were increased at 24 h and inhibited at 48 h by 20 mM taurine while HNF4α was induced after both of the 24 h and 48 h treatment. Taurine could enhance CYP7A1 expression by inducing HNF4α and inhibiting MEK1/2 and p-c-Jun expressions to promote intracellular cholesterol metabolism.

  8. Specific binding of tubeimoside-2 with proteins in hepatocarcinoma HepG2 cells: investigation by molecular spectroscopy

    Science.gov (United States)

    Yang, Sun; Shi-Sheng, Sun; Ying-Yong, Zhao; Jun, Fan

    2012-07-01

    In this study, we compared different binding interactions of TBMS2 with proteins both in hepatocarcinoma HepG2 cells and in normal embryo hepatic L02 cells by using fluorescence, absorption, and CD spectroscopy. The fluorescence data revealed that the fluorescence intensity of proteins in the HepG2 and L02 cells decreased in the presence of TBMS2 by 30.79% and 12.01%, respectively. Binding constants and thermodynamic parameters were obtained for systems of TBMS2 with the two kinds of cell proteins. The results indicated that HepG2 cell proteins had a higher TBMS2 binding activity than those in the L02 cells. Analysis of the TBMS2 cytotoxic activities showed that TBMS2 could selectively induce apoptosis of HepG2 cells by binding to them, while its apoptotic effect on L02 cells was relatively weaker.

  9. Lipotoxicity in HepG2 cells triggered by free fatty acids.

    Science.gov (United States)

    Yao, Hong-Rui; Liu, Jun; Plumeri, Daniel; Cao, Yong-Bing; He, Ting; Lin, Ling; Li, Yu; Jiang, Yuan-Ying; Li, Ji; Shang, Jing

    2011-05-15

    The goal of this study was to investigate the lipid accumulation and lipotoxicity of free fatty acids (FFAs) induced in HepG2 cells. HepG2 cells were co-incubated with various concentrations of FFAs for 24h and the intracellular lipid contents were observed by Oil Red O and Nile Red staining methods. The lipotoxicity of HepG2 cells were then detected by Hoechest 33342/PI, Annexin V-FITC/PI double-staining and 3-(4,5-dimethylthiazol-2-yl)-2,5-di phenyltetrazolium bromide (MTT) experiment tests. The experiments showed a lipid accumulation and lipotoxicity by increasing FFA concentration gradients. Through cell morphological observation and quantitative analysis, FFAs have shown to increase in a dose-dependent manner compared with the control group. The data collected from hoechst 33342/PI, annexin V-FITC/PI double staining and also MTT experiments showed that cell apoptosis and necrosis significantly increased with increasing FFA concentrations. Apoptosis was not obvious in the 1 mM FFAs-treated group compared to the other two groups. In a certain concentration range, FFAs induced intracellular lipid accumulation and lipotoxicity of HepG2 cells in a dose-dependent manner.

  10. SH2 domain-containing inositol 5-phosphatase (SHIP2) inhibition ameliorates high glucose-induced de-novo lipogenesis and VLDL production through regulating AMPK/mTOR/SREBP1 pathway and ROS production in HepG2 cells.

    Science.gov (United States)

    Gorgani-Firuzjaee, Sattar; Meshkani, Reza

    2015-12-01

    Hepatic de-novo lipogenesis and production of triglyceride rich very low density lipoprotein (VLDL) is increased in the state of insulin resistance, however, the role of a negative regulator of the insulin signaling pathway, the SH2 domain-containing inositol 5-phosphatase (SHIP2) in this process, remains unknown. In the present study, we studied the molecular mechanisms linking SHIP2 expression to metabolic dyslipidemia using overexpression or suppression of SHIP2 gene in HepG2 cells exposed to high glucose (33 mM). The results showed that high glucose induced SHIP2 mRNA and protein levels in HepG2 cells. Overexpression of the dominant negative mutant SHIP2 (SHIP2-DN) ameliorated high glucose-induced de-novo lipogenesis and secretion of apoB containing lipoprotein in HepG2 cells, as demonstrated by a reduction in both secreted apoB and MTP expression, and decreased triglyceride levels and the expression of lipogenic genes such as SREBP1c, FAS and ACC. Overexpression of the SHIP2-DN decreased high glucose-induced apoB containing lipoproteins secretion via reduction in ROS generation, JNK phosphorylation and Akt activation. Furthermore, using the specific inhibitor and activator, it was found that the AMPK/mTOR/SREBP1 is the signaling pathway that mediates the effects of SHIP2 modulation on hepatic de-novo lipogenesis. Taken together, these findings suggest that SHIP2 is an important regulator of hepatic lipogenesis and lipoprotein secretion in insulin resistance state. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Fucoxanthin Attenuates Rifampin-Induced Cytochrome P450 3A4 (CYP3A4 and Multiple Drug Resistance 1 (MDR1 Gene Expression Through Pregnane X Receptor (PXR-Mediated Pathways in Human Hepatoma HepG2 and Colon Adenocarcinoma LS174T Cells

    Directory of Open Access Journals (Sweden)

    Miao-Lin Hu

    2012-01-01

    Full Text Available Pregnane X receptor (PXR has been reported to regulate the expression of drug-metabolizing enzymes, such as the cytochrome P450 3A (CYP3A family and transporters, such as multiple drug resistance 1 (MDR1. Fucoxanthin, the major carotenoid in brown sea algae, is a putative chemopreventive agent. In this study, we determined whether fucoxanthin could overcome drug resistance through attenuation of rifampin-induced CYP3A4 and MDR1 gene expression by PXR-mediated pathways in HepG2 hepatoma cells. We found that fucoxanthin (1–10 μM significantly attenuated rifampin (20 μM-induced CYP3A4, MDR1 mRNA and CYP3A4 protein expression at 24 h of incubation. Mechanistically, fucoxanthin strongly attenuated the PXR-mediated CYP3A4 promoter activity in HepG2 cells. In addition, fucoxanthin attenuated constitutive androstane receptor (CAR- and rPXR-mediated CYP3A4 promoter activity in this cell line. Using the mammalian two-hybrid assay, we found that fucoxanthin significantly decreased the interaction between PXR and SRC-1, a PXR co-activator. Thus, fucoxanthin can decrease rifampin-induced CYP3A4 and MDR1 expression through attenuation of PXR-mediated CYP3A4 promoter activation and interaction between PXR and co-activator. These findings could lead to potentially important new therapeutic and dietary approaches to reduce the frequency of adverse drug reactions.

  12. Anticancer Effects of 1,3-Dihydroxy-2-Methylanthraquinone and the Ethyl Acetate Fraction of Hedyotis Diffusa Willd against HepG2 Carcinoma Cells Mediated via Apoptosis.

    Directory of Open Access Journals (Sweden)

    Yun-Lan Li

    Full Text Available Hedyotis Diffusa Willd, used in Traditional Chinese Medicine, is a treatment for various diseases including cancer, owing to its mild effectiveness and low toxicity. The aim of this study was to identify the main anticancer components in Hedyotis Diffusa Willd, and explore mechanisms underlying their activity. Hedyotis Diffusa Willd was extracted and fractionated using ethyl acetate to obtain the H-Ethyl acetate fraction, which showed higher anticancer activity than the other fractions obtained against HepG2 cells with sulforhodamine B assays. The active component of the H-Ethyl acetate fraction was identified to be 1,3-dihydroxy-2-methylanthraquinone (DMQ with much high inhibitory rate up to 48.9 ± 3.3% and selectivity rate up to 9.4 ± 4.5 folds (p<0.01 at 125 μmol/L. HepG2 cells treated with the fraction and DMQ visualized morphologically using light and fluorescence microscopy. Annexin V--fluorescein isothiocyanate / propidium iodide staining flow cytometry, DNA ladder and cell cycle distribution assays. Mechanistic studies showed up-regulation of caspase-3, -8, and -9 proteases activities (p<0.001, indicating involvement of mitochondrial apoptotic and death receptor pathways. Further studies revealed that reactive oxygen species in DMQ and the fraction treated HepG2 cells increased (p<0.01 while mitochondrial membrane potential reduced significantly (p<0.001 compared to the control by flow cytometry assays. Western blot analysis showed that Bax, p53, Fas, FasL, p21 and cytoplasmic cytochrome C were up-regulated (p<0.01, while Bcl-2, mitochondrial cytochrome C, cyclin E and CDK 2 were down-regulated dose-dependently (p<0.01. The reverse transcriptase-polymerase chain reaction showed that mRNA expressions of p53 and Bax increased (p<0.001 while that of Bcl-2 decreased (p<0.001. Pre-treatment with caspase-8 inhibitor Z-IETD-FMK, or caspase-9 inhibitor Z-LEHD-FMK, attenuated the growth-inhibitory and apoptosis-inducing effects of DMQ and the

  13. HepG2 human hepatocarcinomas cells sensitization by endogenous porphyrins

    Science.gov (United States)

    Vonarx-Coinsmann, Veronique; Foultier, Marie-Therese; de Brito, Leonor X.; Morlet, Laurent; Patrice, Thierry

    1995-03-01

    We assessed the ability of the human hepatocarcinoma cell line HepG2 to synthesize PpIX in vitro from exogenous ALA and analyzed ALA-induced toxicity and phototoxicity on this cell line. ALA induced a slight dose-dependent dark toxicity, with 79 and 66% cell survival respectively for ALA 50 and 100 mg/ml after 3-h incubation. Whereas the same treatment followed by laser irradiation (l equals 632 nm, 25 J/sq cm) induced dose-dependent phototoxicity, with 54 and 19% cell survival 24 h after PDT. Whatever the incubation time with ALA, a 3-h delay before light exposure was found optimal to reach a maximal phototoxicity. Photoproducts induced by porphyrin light irradiation absorbed light in the red spectral region at longer wavelengths than did the original porphyrins. The possible enhancement of PDT effects after ALA HepG2 cell incubation was investigated by irradiating cells successively with red light (l equals 632 nm) and light (l equals 650 nm). Total fluence was kept constant at 25 J/sq cm. Phototoxicity was lower when cells were irradiated for increased periods of l equals 650 nm light than with l equals 632 nm light alone. Any photoproducts involved had either a short life or were poorly photoreactive. HepG2 cells, synthesizing enzymes and precursors of endogenous porphyrin synthesis, represent a good in vitro model for experiments using ALA-PpIX-PDT.

  14. Identification of MicroRNAs Involved in Growth Arrest and Apoptosis in Hydrogen Peroxide-Treated Human Hepatocellular Carcinoma Cell Line HepG2

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    Yuan Luo

    2016-01-01

    Full Text Available Although both oxidative stress and microRNAs (miRNAs play vital roles in physiological and pathological processes, little is known about the interactions between them. In this study, we first described the regulation of H2O2 in cell viability, proliferation, cycle, and apoptosis of human hepatocellular carcinoma cell line HepG2. Then, miRNAs expression was profiled after H2O2 treatment. The results showed that high concentration of H2O2 (600 μM could decrease cell viability, inhibit cell proliferation, induce cell cycle arrest, and finally promote cell apoptosis. Conversely, no significant effects could be found under treatment with low concentration (30 μM. miRNAs array analysis identified 131 differentially expressed miRNAs (125 were upregulated and 6 were downregulated and predicted 13504 putative target genes of the deregulated miRNAs. Gene ontology (GO analysis revealed that the putative target genes were associated with H2O2-induced cell growth arrest and apoptosis. The subsequent bioinformatics analysis indicated that H2O2-response pathways, including MAPK signaling pathway, apoptosis, and pathways in cancer and cell cycle, were significantly affected. Overall, these results provided comprehensive information on the biological function of H2O2 treatment in HepG2 cells. The identification of miRNAs and their putative targets may offer new diagnostic and therapeutic strategies for liver cancer.

  15. Identification of MicroRNAs Involved in Growth Arrest and Apoptosis in Hydrogen Peroxide-Treated Human Hepatocellular Carcinoma Cell Line HepG2.

    Science.gov (United States)

    Luo, Yuan; Wen, Xinyu; Wang, Ling; Gao, Jing; Wang, Zi; Zhang, Chunyan; Zhang, Pengjun; Lu, Chengrong; Duan, Lianning; Tian, Yaping

    2016-01-01

    Although both oxidative stress and microRNAs (miRNAs) play vital roles in physiological and pathological processes, little is known about the interactions between them. In this study, we first described the regulation of H2O2 in cell viability, proliferation, cycle, and apoptosis of human hepatocellular carcinoma cell line HepG2. Then, miRNAs expression was profiled after H2O2 treatment. The results showed that high concentration of H2O2 (600 μM) could decrease cell viability, inhibit cell proliferation, induce cell cycle arrest, and finally promote cell apoptosis. Conversely, no significant effects could be found under treatment with low concentration (30 μM). miRNAs array analysis identified 131 differentially expressed miRNAs (125 were upregulated and 6 were downregulated) and predicted 13504 putative target genes of the deregulated miRNAs. Gene ontology (GO) analysis revealed that the putative target genes were associated with H2O2-induced cell growth arrest and apoptosis. The subsequent bioinformatics analysis indicated that H2O2-response pathways, including MAPK signaling pathway, apoptosis, and pathways in cancer and cell cycle, were significantly affected. Overall, these results provided comprehensive information on the biological function of H2O2 treatment in HepG2 cells. The identification of miRNAs and their putative targets may offer new diagnostic and therapeutic strategies for liver cancer.

  16. Aglycemia keeps mitochondrial oxidative phosphorylation under hypoxic conditions in HepG2 cells

    Czech Academy of Sciences Publication Activity Database

    Plecitá-Hlavatá, Lydie; Ježek, Jan; Ježek, Petr

    2015-01-01

    Roč. 47, č. 6 (2015), s. 467-476 ISSN 0145-479X R&D Projects: GA ČR(CZ) GAP302/10/0346; GA ČR(CZ) GA13-02033S; GA MŠk(CZ) LH11055 Institutional support: RVO:67985823 Keywords : cancer mitochondria * non-canonical response to hypoxia * hypoxia-inducible factor * glutaminolysis * HepG2 cells Subject RIV: ED - Physiology Impact factor: 2.080, year: 2015

  17. Synthesis, characterization of 1,2,4-triazole Schiff base derived 3d-metal complexes: Induces cytotoxicity in HepG2, MCF-7 cell line, BSA binding fluorescence and DFT study.

    Science.gov (United States)

    Tyagi, Prateek; Tyagi, Monika; Agrawal, Swati; Chandra, Sulekh; Ojha, Himanshu; Pathak, Mallika

    2017-01-15

    Two novel Schiff base ligands H2L1 and H2L2 have been synthesized by condensation reaction of amine derivative of 1,2,4-triazole moiety with 2-hydroxy-4-methoxybenzaldehyde. Co(II), Ni(II), Cu(II) and Zn(II) of the synthesized Schiff bases were prepared by using a molar ratio of ligand:metal as 1:1. The structure of the Schiff bases and synthesized metal complexes were established by 1H NMR, UV-Vis, IR, Mass spectrometry and molar conductivity. The thermal stability of the complexes was study by TGA. Fluorescence quenching mechanism of metal complexes 1-4 show that Zn(II) and Cu(II) complex binds more strongly to BSA. In DFT studies the geometries of Schiff bases and metal complexes were fully optimized with respect to the energy using the 6-31+g(d,p) basis set. The spectral data shows that the ligands behaves as binegative tridentate. On the basis of the spectral studies, TGA and DFT data an octahedral geometry has been assigned for Co(II), Ni(II), square planar for Cu(II) and tetrahedral for Zn(II) complexes. The anticancer activity were screened against human breast cancer cell line (MCF-7) and human hepatocellular liver carcinoma cell line (Hep-G2). Result indicates that metal complexes shows increase cytotoxicity in proliferation to cell lines as compared to free ligand. Copyright © 2016. Published by Elsevier B.V.

  18. The Inhibitory Effect of 3β-Hydroxy-12-oleanen-27-oic Acid on Growth and Motility of Human Hepatoma HepG2 Cells through JNK and Akt Signaling Pathway

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    Juanjuan Wang

    2013-01-01

    Full Text Available 3β-Hydroxy-12-oleanen-27-oic acid (ATA was a main antitumor active triterpene from the rhizomes of Astilbe chinensis. In this study, we investigated its effects on growth, apoptosis, cell cycle, motility/invasion, and metatasis in human hepatoma HepG2 cells in vitro and antimetastasis of B16-F10 melanoma in mice in vivo, as well as its molecular mechanisms of action using a high-throughput Cancer Pathway Finder PCR Array. ATA could not only induce tumor cells into apoptosis through the activation of both extrinsic and intrinsic pathways, arrest HepG2 cells in G2/M phase, but also suppress the invasion and metastasis abilities of HepG2 cells and the lung metastasis of B16-F10 melanoma in mice. PCR array assay revealed that ATA upregulated 9 genes including CDKN1A, MDM2, CFLAR (CASPER, TNFRSF10B (DR5, c-Jun, IL-8, THBS1, SERPINB5 (maspin, and TNF and downregulated 8 genes such as CCNE1, AKT, ANGPT1, TEK, TGFBR1, MMP9, U-PA, and S100A4. These results indicate that ATA could exert antitumor effects through activating JNK/MAPK and suppressing AKT signal transduction pathways and that ATA might be a potent anticancer agent.

  19. Synergistic complex from plants Solanaceae exhibits cytotoxicity for the human hepatocellular carcinoma cell line HepG2.

    Science.gov (United States)

    Schwarzlin, Romina; Pušenjak, Nika; Makuc, Damjan; Križman, Mitja; Vovk, Irena; Plavec, Janez; Švajger, Urban

    2016-10-18

    It had been demonstrated that sugars from various plants can act as potent agents, which induce apoptosis of cancer cells. Using HPLC, we fractionated a mixture of two plant extracts from the plant family Solanaceae, namely Capsicum chinense and the plant family Amaryllidaceae namely Allium sativum. We evaluated the effect of different fractions on apoptosis of HepG2 cell line. The most effective fraction was further studied to determine its molecular composition using mass spectrometry (MS) and NMR. We further evaluated the effect of determined molecular composition found in the selected fraction by using a mixture of commercially available substances, which were found in the fraction and tested its pro-apoptotic effect on HepG2 cells. To get some insight into potential apoptotic mechanisms we studied caspase-3 activity and mitochondrial integrity in treated cells. Out of 93 fractions obtained by HPLC from the plant extract we found HPLC fraction 10 (10 min elution) was the most effective. MS and NMR studies revealed high presence of cellobiose together with vitamin C, sulphur (S) and trace amounts of selenium (Se). HPLC fraction 10 triggered apoptosis of HepG2 within 3 h in the 0.01-1.0 mg/mL concentration range. Furthermore, a mixture of pure cellobiose, vitamin C, S and Se (complex cellobiose/C/S/Se) had a very similar capacity in inducing apoptosis of HepG2 cells compared to HPLC fraction 10. Complex cellobiose/C/S/Se was capable of inducing caspase-3 activity and led to loss of mitochondrial integrity. The capacity of cellobiose alone to induce apoptosis of HepG2 was approximately 1000-fold lower compared to complex cellobiose/C/S/Se. In this study we present the highly synergistic effect of a unique complex consisting of cellobiose, vitamin C, sulphur and selenium on triggering the apoptosis of human hepatocellular carcinoma (HepG2) cell line.

  20. MSC(TRAIL)-mediated HepG2 cell death in direct and indirect co-cultures.

    Science.gov (United States)

    Sun, Xu-Yong; Nong, Jiang; Qin, Ke; Lu, Hong; Moniri, Mani R; Dai, Long-Jun; Warnock, Garth L

    2011-11-01

    Mesenchymal stem cells (MSCs) have attracted great interest in cancer therapy since the discovery of their tumor tropism. This study was performed to investigate the effects of TNF-related apoptosis-inducing ligand (TRAIL)-engineered MSCs on hepatocellular carcinoma (HCC) cells (HepG2) under different culture conditions. MSCs engineered with non-secreting TRAIL (MSC(TRAIL-GFP)) (GFP, green fluorescence protein) and secreting TRAIL (MSC(stTRAIL)) were used for the direct co-cultures, and conditioned media (CM) from corresponding cultures were applied to HepG2 as indirect co-cultures. Immunoblotting, ELISA and FACS analysis were used to detect the expression of TRAIL and TRAIL receptors. Cell death was assessed using live/dead assay. Death receptor (DR) 5 was identified on the HepG2 cells. The expression of TRAIL was confirmed in the cell lysates (MSC(TRAIL-GFP) >MSC(stTRAIL)) and the conditioned media (MSC(stTRAIL) >MSC(TRAIL-GFP)). Higher cell death was observed in high MSC/HepG2 ratio co-cultures. HepG2 cell death was proportionally related to CM from MSC(TRAIL-GFP) and MSC(stTRAIL). MSCs exhibit intrinsic inhibition of HepG2 which is potentiated by TRAIL-transfection.

  1. Extracellular visfatin activates gluconeogenesis in HepG2 cells through the classical PKA/CREB-dependent pathway.

    Science.gov (United States)

    Choi, Y J; Choi, S-E; Ha, E S; Kang, Y; Han, S J; Kim, D J; Lee, K W; Kim, H J

    2014-04-01

    Adipokines reportedly affect hepatic gluconeogenesis, and the adipokine visfatin is known to be related to insulin resistance and type 2 diabetes. However, whether visfatin contributes to hepatic gluconeogenesis remains unclear. Visfatin, also known as nicotinamide phosphoribosyltransferase (NAMPT), modulates sirtuin1 (SIRT1) through the regulation of nicotinamide adenine dinucleotide (NAD). Therefore, we investigated the effect of extracellular visfatin on glucose production in HepG2 cells, and evaluated whether extracellular visfatin affects hepatic gluconeogenesis via an NAD+-SIRT1-dependent pathway. Treatment with visfatin significantly increased glucose production and the mRNA expression and protein levels of phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase) in HepG2 cells in a time- and concentration-dependent manner. Knockdown of SIRT1 had no remarkable effect on the induction of gluconeogenesis by visfatin. Subsequently, we evaluated if extracellular visfatin stimulates the production of gluconeogenic enzymes through the classical protein kinase A (PKA)/cyclic AMP-responsive element (CRE)-binding protein (CREB)-dependent process. The phosphorylation of CREB and PKA increased significantly in HepG2 cells treated with visfatin. Additionally, knockdown of CREB and PKA inhibited visfatin-induced gluconeogenesis in HepG2 cells. In summary, extracellular visfatin modulates glucose production in HepG2 cells through the PKA/CREB pathway, rather than via SIRT1 signaling. © Georg Thieme Verlag KG Stuttgart · New York.

  2. Selective killing of hepatocellular carcinoma HepG2 cells by three-dimensional nanographene nanoparticles based on triptycene

    Science.gov (United States)

    Xiong, Xiaoqin; Gan, Lu; Liu, Ying; Zhang, Chun; Yong, Tuying; Wang, Ziyi; Xu, Huibi; Yang, Xiangliang

    2015-03-01

    Carbon-based materials have been widely used in the biomedical fields including drug delivery and cancer therapies. In this paper, a recently synthesized three-dimensional nanographene (NG) based on triptycene self-assembles into nanoparticles which selectively kill human hepatocellular carcinoma HepG2 cells as compared to human normal liver HL7702 cells. Obvious differences in cellular accumulation, the endocytic pathway and intracellular trafficking of NG nanoparticles are observed in HepG2 cells and HL7702 cells. Further studies reveal that NG nanoparticles significantly increase the levels of reactive oxygen species (ROS) in HepG2 cells, but not in HL7702 cells. NG nanoparticle-induced ROS result in apoptosis induction and the decrease in mitochondrial membrane potential in HepG2 cells. Moreover, IKK/nuclear factor-κB (NF-κB) signaling is found to be activated by NG nanoparticle-induced ROS and serves to antagonize NG nanoparticle-induced apoptosis in HepG2 cells. Our studies show that the distinct behaviors of cellular uptake and ROS-mediated cytotoxicity are responsible for the selective killing of HepG2 cells. This study provides a foundation for understanding the mechanism of selective induction of apoptosis in cancer cells by NG nanoparticles and designing more effective chemotherapeutical agents.Carbon-based materials have been widely used in the biomedical fields including drug delivery and cancer therapies. In this paper, a recently synthesized three-dimensional nanographene (NG) based on triptycene self-assembles into nanoparticles which selectively kill human hepatocellular carcinoma HepG2 cells as compared to human normal liver HL7702 cells. Obvious differences in cellular accumulation, the endocytic pathway and intracellular trafficking of NG nanoparticles are observed in HepG2 cells and HL7702 cells. Further studies reveal that NG nanoparticles significantly increase the levels of reactive oxygen species (ROS) in HepG2 cells, but not in HL7702

  3. Synergy between sulforaphane and selenium in the up-regulation of thioredoxin reductase and protection against hydrogen peroxide-induced cell death in human hepatocytes.

    Science.gov (United States)

    Li, Dan; Wang, Wei; Shan, Yujuan; Barrera, Lawrence N; Howie, Alexander F; Beckett, Geoffrey J; Wu, Kun; Bao, Yongping

    2012-07-15

    Dietary isothiocyanates and selenium are chemopreventive agents and potent inducers of antioxidant enzymes. It has been previously shown that sulforaphane and selenium have a synergistic effect on the upregulation of thioredoxin reductase-1 (TrxR-1) in human hepatoma HepG2 cells. In this paper, further evidence is presented to show that sulforaphane and selenium synergistically induce TrxR-1 expression in immortalised human hepatocytes. Sulforaphane was found to be more toxic toward hepatocytes than HepG2 cells with IC50=25.1 and 56.4 μM, respectively. Sulforaphane can protect against hydrogen peroxide-induced cell death and this protection was enhanced by co-treatment with selenium. Using siRNA to knock down TrxR-1 or Nrf2, sulforaphane (5 μM)-protected cell viability was reduced from 73% to 46% and 34%, respectively, suggesting that TrxR-1 is an important enzyme in protection against hydrogen peroxide-induced cell death. Sulforaphane-induced TrxR-1 expression was positively associated with significant levels of Nrf2 translocation into the nucleus, but co-treatment with selenium showed no significant increase in Nrf2 translocation. Moreover, MAPK (ERK, JNK and p38) and PI3K/Akt signalling pathways were found to play no significant role in sulforaphane-induced Nrf2 translocation into the nucleus. However, blocking ERK and JNK signalling pathways decreased sulforaphane-induced TrxR-1 mRNA by about 20%; whereas blocking p38 and PI3K/AKT increased TrxR-1 transcription. In summary, a combination of sulforaphane and selenium resulted in a synergistic upregulation of TrxR-1 that contributed to the enhanced protection against free radical-mediated oxidative damage in human hepatocytes. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Antiproliferative Effect of the Isoquinoline Alkaloid Papaverine in Hepatocarcinoma HepG-2 Cells — Inhibition of Telomerase and Induction of Senescence

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    Sakineh Kazemi Noureini

    2014-08-01

    Full Text Available Cancer cells are often immortal through up-regulation of the hTERT gene, which encodes the catalytic subunit of a special reverse transcriptase to overcome end-replication problem of chromosomes. This study demonstrates that papaverine, an isoquinoline alkaloid from the Papaveraceae, can overcome telomerase dependent immortality of HepG-2 cells that was used as a model of hepatocarcinoma. Although this alkaloid does not directly interact with telomeric sequences, papaverine inhibits telomerase through down-regulation of hTERT, which was analysed using thermal FRET and qRT-PCR, respectively. The IC50 values for the reduction of both telomerase activity and hTERT expression was 60 µM, while IC50 for cytotoxicity was 120 µM. Repeated treatments of the cells with very low non-toxic concentrations of papaverine resulted in growth arrest and strong reduction of population doublings after 40 days. This treatment induced senescent morphology in HepG-2 cells, which was evaluated by beta-galactosidase staining. Altogether, papaverine can be regarded as a promising model compound for drug design targeting cancer development.

  5. PCBP-1 regulates alternative splicing of the CD44 gene and inhibits invasion in human hepatoma cell line HepG2 cells

    Directory of Open Access Journals (Sweden)

    Ge Changhui

    2010-04-01

    Full Text Available Abstract Background PCBP1 (or alpha CP1 or hnRNP E1, a member of the PCBP family, is widely expressed in many human tissues and involved in regulation of transcription, transportation process, and function of RNA molecules. However, the role of PCBP1 in CD44 variants splicing still remains elusive. Results We found that enforced PCBP1 expression inhibited CD44 variants expression including v3, v5, v6, v8, and v10 in HepG2 cells, and knockdown of endogenous PCBP1 induced these variants splicing. Invasion assay suggested that PCBP1 played a negative role in tumor invasion and re-expression of v6 partly reversed the inhibition effect by PCBP1. A correlation of PCBP1 down-regulation and v6 up-regulation was detected in primary HCC tissues. Conclusions We first characterized PCBP1 as a negative regulator of CD44 variants splicing in HepG2 cells, and loss of PCBP1 in human hepatic tumor contributes to the formation of a metastatic phenotype.

  6. Cytotoxicity and apoptotic effects of tea polyphenol-loaded chitosan nanoparticles on human hepatoma HepG2 cells

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Jin [Key Laboratory of Tea Biochemistry and Biotechnology of Ministry of Education and Ministry of Agriculture, Anhui Agricultural University, Hefei 230036 (China); College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095 (China); Li, Feng [College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095 (China); Fang, Yong; Yang, Wenjian [College of Food Science and Engineering, Nanjing University of Finance and Economics, Nanjing 210023 (China); An, Xinxin; Zhao, Liyan; Xin, Zhihong; Cao, Lin [College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095 (China); Hu, Qiuhui, E-mail: qiuhuihu@njau.edu.cn [College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095 (China); College of Food Science and Engineering, Nanjing University of Finance and Economics, Nanjing 210023 (China)

    2014-03-01

    Tea polyphenols have strong antioxidant and antitumor activities. However, these health benefits are limited due to their poor in vivo stability and low bioavailability. Chitosan nanoparticles as delivery systems may provide an alternative approach for enhancing bioavailability of poorly absorbed drugs. In this study, tea polyphenol-loaded chitosan nanoparticles have been prepared using two different chitosan biomaterials, and their antitumor effects were evaluated in HepG2 cells, including cell cytotoxicity comparison, cell morphology analysis, cell apoptosis and cell cycle detection. The results indicated that the tea polyphenol-loaded chitosan nanoparticles showed a branch shape and heterogeneous distribution in prepared suspension. MTT assay suggested that tea polyphenol-loaded chitosan nanoparticles could inhibit the proliferation of HepG2 cells, and the cytotoxicity rates were increased gradually and appeared an obvious dose-dependent relationship. Transmission electron microscope images showed that the HepG2 cells treated with tea polyphenol-loaded chitosan nanoparticles exhibited some typical apoptotic features, such as microvilli disappearance, margination of nuclear chromatin, intracytoplasmic vacuoles and the mitochondrial swelling. In addition, the tea polyphenol-loaded chitosan nanoparticles had relatively weak inhibitory effects on HepG2 cancer cells compared with tea polyphenols. Tea polyphenols not only induced cancer cell apoptosis, but also promoted their necrosis. However, tea polyphenol-loaded chitosan nanoparticles exhibited their antitumor effects mainly through inducing cell apoptosis. Our results revealed that the inhibition effects of tea polyphenol-loaded chitosan nanoparticles on tumor cells probably depended on their controlled drug release and effective cell delivery. The chitosan nanoparticles themselves as the delivery carrier showed limited antitumor effects compared with their encapsulated drugs. - Highlights: • Tea polyphenol

  7. The Growth Suppressing Effects of Girinimbine on Hepg2 Involve Induction of Apoptosis and Cell Cycle Arrest

    Directory of Open Access Journals (Sweden)

    Tang Sook Wah

    2011-08-01

    Full Text Available Murraya koenigii is an edible herb widely used in folk medicine. Here we report that girinimbine, a carbazole alkaloid isolated from this plant, inhibited the growth and induced apoptosis in human hepatocellular carcinoma, HepG2 cells. The MTT and LDH assay results showed that girinimbine decreased cell viability and increased cytotoxicity in a dose-and time-dependent manner selectively. Girinimbine-treated HepG2 cells showed typical morphological features of apoptosis, as observed from normal inverted microscopy and Hoechst 33342 assay. Furthermore, girinimbine treatment resulted in DNA fragmentation and elevated levels of caspase-3 in HepG2 cells. Girinimbine treatment also displayed a time-dependent accumulation of the Sub-G0/G1 peak (hypodiploid and caused G0/G1-phase arrest. Together, these results demonstrated for the first time that girinimbine could effectively induce programmed cell death in HepG2 cells and suggests the importance of conducting further investigations in preclinical human hepatocellular carcinoma models, especially on in vivo efficacy, to promote girinimbine for use as an anticancer agent against hepatocellular carcinoma.

  8. Proanthocyanidins modulate microRNA expression in human HepG2 cells.

    Directory of Open Access Journals (Sweden)

    Anna Arola-Arnal

    Full Text Available Mi(croRNAs are small non-coding RNAs of 18-25 nucleotides in length that modulate gene expression at the post-transcriptional level. These RNAs have been shown to be involved in a several biological processes, human diseases and metabolic disorders. Proanthocyanidins, which are the most abundant polyphenol class in the human diet, have positive health effects on a variety of metabolic disorders such as inflammation, obesity, diabetes and insulin resistance. The present study aimed to evaluate whether proanthocyanidin-rich natural extracts modulate miRNA expression. Using microarray analysis and Q-PCR, we investigated miRNA expression in HepG2 cells treated with proanthocyanidins. Our results showed that when HepG2 cells were treated with grape seed proanthocyanidin extract (GSPE, cocoa proanthocyanidin extract (CPE or pure epigallocatechin gallate isolated from green tea (EGCG, fifteen, six and five differentially expressed miRNAs, respectively, were identified out of 904 mRNAs. Specifically, miR-30b* was downregulated by the three treatments, and treatment with GSPE or CPE upregulated miR-1224-3p, miR-197 and miR-532-3p. Therefore, these results provide evidence of the capacity of dietary proanthocyanidins to influence microRNA expression, suggesting a new mechanism of action of proanthocyanidins.

  9. Statins Activate Human PPAR Promoter and Increase PPAR mRNA Expression and Activation in HepG2 Cells

    Directory of Open Access Journals (Sweden)

    Makoto Seo

    2008-01-01

    Full Text Available Statins increase peroxisome proliferator-activated receptor (PPAR mRNA expression, but the mechanism of this increased PPAR production remains elusive. To examine the regulation of PPAR production, we examined the effect of 7 statins (atorvastatin, cerivastatin, fluvastatin, pitavastatin, pravastatin, rosuvastatin, and simvastatin on human PPAR promoter activity, mRNA expression, nuclear protein levels, and transcriptional activity. The main results are as follows. (1 Majority of statins enhanced PPAR promoter activity in a dose-dependent manner in HepG2 cells transfected with the human PPAR promoter. This enhancement may be mediated by statin-induced HNF-4. (2 PPAR mRNA expression was increased by statin treatment. (3 The PPAR levels in nuclear fractions were increased by statin treatment. (4 Simvastatin, pravastatin, and cerivastatin markedly enhanced transcriptional activity in 293T cells cotransfected with acyl-coenzyme A oxidase promoter and PPAR/RXR expression vectors. In summary, these data demonstrate that PPAR production and activation are upregulated through the PPAR promoter activity by statin treatment.

  10. Newly developed chitosan-silver hybrid nanoparticles: biosafety and apoptosis induction in HepG2 cells

    Science.gov (United States)

    El-Sherbiny, Ibrahim M.; Salih, Ehab; Yassin, Abdelrahman M.; Hafez, Elsayed E.

    2016-07-01

    The present study reports the biosafety assessment, the exact molecular effects, and apoptosis induction of newly developed chitosan-silver hybrid nanoparticles (Cs-Ag NPs) in HepG2 cells. The investigated hybrid NPs were green synthesized using Cs/grape leaves aqueous extract (Cs/GLE) or Cs/GLE NPs as reducing and stabilizing agents. The successful formation of Cs/GLE NPs and Cs-Ag hybrid NPs has been confirmed by UV-Vis spectrophotometry, FTIR spectroscopy, XRD, and HRTEM. From the TEM analysis, the prepared Cs/GLE NPs are uniform and spherical with an average size of 150 nm, and the AgNPs (5-10 nm) were formed mainly on their surface. The UV-Vis spectra of Cs-Ag NPs showed a surface plasmon resonance (SPR) peak at about 450 nm confirming their formation. The synthesized Cs-Ag NPs were found to be crystalline as shown by XRD patterns with fcc phase oriented along the (111), (200), (220), and (311) planes. The cytotoxicity patterns, the antiproliferative activities, and the possible mechanisms of anticancer activity at molecular level of the newly developed Cs-Ag hybrid NPs were investigated. Cytotoxicity patterns of all the preparations demonstrated that the nontoxic treatment concentrations are ranged from 0.39 to 50 %, and many of the newly prepared Cs-Ag hybrid NPs showed high anticancer activities against HpG2 cells, and induced cellular apoptosis by downregulating BCL2 gene and upregulating P53.

  11. Inhibition of adhesion and metastasis of HepG2 hepatocellular carcinoma cells in vitro by DNA aptamer against sialyl Lewis X.

    Science.gov (United States)

    Wang, Xiao-Kang; Peng, Yan; Tao, Hao-Ran; Zhou, Fen-Fang; Zhang, Chi; Su, Fei; Wang, Shi-Pei; Liu, Qing; Xu, Li-Hua; Pan, Xue-Kai; Xie, Wei; Feng, Mao-Hui

    2017-06-01

    The sialyl Lewis X (SLe x ) antigen encoded by the FUT7 gene is the ligand of endotheliam-selectin (E-selectin). The combination of SLe x antigen and E-selectin represents an important way for malignant tumor metastasis. In the present study, the effect of the SLe x -binding DNA aptamer on the adhesion and metastasis of hepatocellular carcinoma HepG2 cells in vitro was investigated. Reverse transcription-polymerase chain reaction (RT-PCR) and immunofluorescence staining were conducted to detect the expression of FUT7 at both transcriptional and translational levels. The SLe x expression in HepG2 cells treated with different concentrations of SLe x -binding DNA aptamer was detected by flow cytometry. Besides, the adhesion, migration, and invasion of HepG2 cells were measured by cell adhesion assay, and the Transwell migration and invasion assay. The results showed that the FUT7 expression was up-regulated at both mRNA and protein levels in HepG2 cells. SLe x -binding DNA aptamer could significantly decrease the expression of SLe x in HepG2 cells. The cell adhesion assay revealed that the SLe x -binding DNA aptamer could effectively inhibit the interactions between E-selectin and SLe x in the HepG2 cells. Additionally, SLe x -binding DNA aptamers at 20 nmol/L were found to have the similar effect to the monoclonal antibody CSLEX-1. The Transwell migration and invasion assay revealed that the number of penetrating cells on the down-side of Transwell membrane was significantly less in cells treated with 5, 10, 20 nmol/L SLe x -binding DNA aptamer than those in the negative control group (Paptamer could significantly inhibit the in vitro adhesion, migration, and invasion of HepG2 cells, suggesting that the SLe x -binding DNA aptamer may be used as a potential molecular targeted drug against metastatic hepatocellular carcinoma.

  12. Ethanol enhanced the genotoxicity of acrylamide in human, metabolically competent HepG2 cells by CYP2E1 induction and glutathione depletion.

    Science.gov (United States)

    Lamy, Evelyn; Völkel, Yvonne; Roos, Peter H; Kassie, Fekadu; Mersch-Sundermann, Volker

    2008-03-01

    In the present study, the genotoxicity of acrylamide (AA) was investigated in HepG2 cells using SCGE. Additionally, the influence of ethanol on the modulation of AA-induced DNA-migration caused by CYP2E1-upregulation and/or GSH-depletion was examined in the same cell line. For the ethanol/AA combination assays, the cells were treated with ethanol for 24h prior to exposure to 5mM AA for another 24h. 1.25 to 10mM AA-induced DNA migration (OTM) in HepG2 cells in a concentration-dependent manner, e.g., exposure to 10mM AA, resulted in an 8-fold increase of DNA migration compared to the negative control. Treatment with 120mM ethanol prior to exposure to 5mM AA increased the level of DNA migration more than 2-fold as compared to cells treated with 5mM AA alone. Immunoblotting showed a clear ethanol-induced increase of CYP2E1, which plays a pivotal role in AA toxification. Additionally, intracellular GSH levels were significantly reduced after ethanol or AA treatment. In the ethanol/AA combination experiments, GSH depletion was comparable to the additive effect of the single compounds. No induction of apoptosis (ssDNA assay), but necrosis was identified as responsible for the reduction of viability with increasing compound concentration. The data clearly show a higher genotoxic potential of ethanol/AA combination treatment compared to AA treatment alone. In conclusion, both the ethanol-mediated induction of CYP2E1 and the depletion of GSH provide a mechanistic explanation for the over-additive effects of ethanol and AA. Even though the concentrations used in this study were rather high, consequences for the dietary intake of AA-containing food and alcoholic beverages should be discussed.

  13. Induction of apoptosis in HepG2 cells by solanine and Bcl-2 protein.

    Science.gov (United States)

    Ji, Y B; Gao, S Y; Ji, C F; Zou, X

    2008-01-17

    The nightshade (Solanum nigrum Linn.) has been widely used in Chinese traditional medicine as a remedy for the treatment of digestive system cancer. The anti-tumor activity of solanine, a steroid alkaloid isolated from the nightshade has been demonstrated. To observe the effect of anti-tumor and mechanism of solanine. The MTT assay was used to evaluate the IC(50) on the three digestive system tumor cell lines. The effect on the morphology was observed with a laser confocal microscopy; the rate of apoptosis and the cell cycle were measured using flow cytometry (FCM); the expression of Bcl-2 protein was measured by Western blot. The results show that the IC(50) for HepG(2), SGC-7901, and LS-174 were 14.47, >50, and >50 microg/ml, respectively; the morphology of cells in the negative control was normal; for the treated groups, typical signs for apoptosis were found. The rate of apoptosis in HepG(2) cells induced by solanine was found to be 6.0, 14.4, 17.3, 18.9, and 32.2%, respectively. Observation of the cell cycle showed that cells in the G(2)/M phases disappeared while the number of cells in the S phase increased significantly for treated groups. Western blot showed that solanine decreased the expression of Bcl-2 protein. Therefore, the target of solanine in inducing apoptosis in HepG(2) cells seems to be mediated by the inhibition in the expression of Bcl-2 protein.

  14. Inferring Toxicological Responses of HepG2 Cells from ...

    Science.gov (United States)

    Understanding the dynamic perturbation of cell states by chemicals can aid in for predicting their adverse effects. High-content imaging (HCI) was used to measure the state of HepG2 cells over three time points (1, 24, and 72 h) in response to 976 ToxCast chemicals for 10 different concentrations (0.39-200µM). Cell state was characterized by p53 activation (p53), c-Jun activation (SK), phospho-Histone H2A.x (OS), phospho-Histone H3 (MA), alpha tubulin (Mt), mitochondrial membrane potential (MMP), mitochondrial mass (MM), cell cycle arrest (CCA), nuclear size (NS) and cell number (CN). Dynamic cell state perturbations due to each chemical concentration were utilized to infer coarse-grained dependencies between cellular functions as Boolean networks (BNs). BNs were inferred from data in two steps. First, the data for each state variable were discretized into changed/active (> 1 standard deviation), and unchanged/inactive values. Second, the discretized data were used to learn Boolean relationships between variables. In our case, a BN is a wiring diagram between nodes that represent 10 previously described observable phenotypes. Functional relationships between nodes were represented as Boolean functions. We found that inferred BN show that HepG2 cell response is chemical and concentration specific. We observed presence of both point and cycle BN attractors. In addition, there are instances where Boolean functions were not found. We believe that this may be either

  15. Suppression of Idol expression is an additional mechanism underlying statin-induced up-regulation of hepatic LDL receptor expression.

    Science.gov (United States)

    Dong, Bin; Wu, Minhao; Cao, Aiqin; Li, Hai; Liu, Jingwen

    2011-01-01

    Recent studies have identified proprotein convertase subtilisin/kexin type 9 (PCSK9) and Idol as negative regulators of low density lipoprotein receptor (LDLR) protein stability. While the induction of PCSK9 transcription has been recognized as a limitation to the statin cholesterol-lowering efficacy at higher doses, it is unknown whether Idol is involved in the statin-mediated up-regulation of the hepatic LDLR. Here we report that statins exert opposite effects on PCSK9 and Idol gene expression in human hepatoma-derived cell lines and primary hepatocytes isolated from hamsters and rats. While PCSK9 expression was induced, the level of Idol mRNA rapidly declined in statin-treated cells in a dose-dependent manner. This differs from the effect of the liver X receptor ligand, GW3965, which increased the expression of both PCSK9 and Idol. We further show that cellular depletion of Idol by siRNA transfection did not change PCSK9 expression levels in control and statin-treated cells; however, the basal level of LDLR protein increased by 60% in Idol siRNA transfected HepG2 cells. More importantly, the increase in LDLR protein abundance by rosuvastatin and atorvastatin treatment was compromised by Idol siRNA transfection. Collectively, our present findings suggest that the suppression of Idol gene expression in liver cells is an additional mechanism underlying the statin-induced up-regulation of hepatic LDLR expression. This may contribute to the hypocholesterolemic effects of statins observed in clinical settings.

  16. Synergetic cholesterol-lowering effects of main alkaloids from Rhizoma Coptidis in HepG2 cells and hypercholesterolemia hamsters.

    Science.gov (United States)

    Kou, Shuming; Han, Bing; Wang, Yue; Huang, Tao; He, Kai; Han, Yulong; Zhou, Xia; Ye, Xiaoli; Li, Xuegang

    2016-04-15

    Hyperlipidemia contributes to the progression of cardiovascular diseases. Main alkaloids from Rhizoma Coptidis including berberine (BBR), coptisine (COP), palmatine (PAL), epiberberine (EPI) and jatrorrhizine (JAT), improved dyslipidemia in hypercholesterolemic hamsters to a different degree. In this study, HepG2 cells and hypercholesterolemic hamsters were used to investigate the synergetic cholesterol-lowering efficacy of these five main alkaloids. The cellular lipid and cholesterol accumulation and in HepG2 cells were evaluated by Oil Red O staining and HPLC analysis. LDL receptor, 3-Hydroxy-3-methylglutaryl CoA reductase (HMGCR) and cholesterol 7-alpha-hydroxylase (CYP7A1) that involving cholesterol metabolism in HepG2 cells were measured by qRT-PCR, western blot and immunofluorescence analysis. The serum profiles including total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-c) and high-density lipoprotein cholesterol (HDL-c), as well as TC and total bile acids (TBA) of feces in hypercholesterolemic hamsters were also measured. As compared to single alkaloids, the combination of five main alkaloids (COM) reduced the lipid and cholesterol accumulation in HepG2 cells more effectively and performed an advantageous effect on controlling TC, TG, LDL-c and HDL-c in hypercholesterolemic hamsters. More effective reduction of TBA and TC levels in feces of hamsters were achieved after the administration of COM. These effects were derived from the up-regulation of LDL receptor and CYP7A1, as well as HMGCR downregulation. Our results demonstrated that COM showed a synergetic cholesterol-lowering efficacy, which was better than single alkaloids and it might be considered as a potential therapy for hypercholesterolemia. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Metabolic Flux Distribution during Defatting of Steatotic Human Hepatoma (HepG2 Cells

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    Gabriel Yarmush

    2016-01-01

    Full Text Available Methods that rapidly decrease fat in steatotic hepatocytes may be helpful to recover severely fatty livers for transplantation. Defatting kinetics are highly dependent upon the extracellular medium composition; however, the pathways involved are poorly understood. Steatosis was induced in human hepatoma cells (HepG2 by exposure to high levels of free fatty acids, followed by defatting using plain medium containing no fatty acids, or medium supplemented with a cocktail of defatting agents previously described before. We measured the levels of 28 extracellular metabolites and intracellular triglyceride, and fed the data into a steady-state mass balance model to estimate strictly intracellular fluxes. We found that during defatting, triglyceride content decreased, while beta-oxidation, the tricarboxylic acid cycle, and the urea cycle increased. These fluxes were augmented by defatting agents, and even more so by hyperoxic conditions. In all defatting conditions, the rate of extracellular glucose uptake/release was very small compared to the internal supply from glycogenolysis, and glycolysis remained highly active. Thus, in steatotic HepG2 cells, glycolysis and fatty acid oxidation may co-exist. Together, these pathways generate reducing equivalents that are supplied to mitochondrial oxidative phosphorylation.

  18. Artesunate enhances γδ T-cell-mediated antitumor activity through augmenting γδ T-cell function and reversing immune escape of HepG2 cells.

    Science.gov (United States)

    Qian, Peng; Zhang, Yong-Wen; Zhou, Zhong-Hai; Liu, Jun-Quan; Yue, Su-Yang; Guo, Xiang-Li; Sun, Lei-Qing; Lv, Xiao-Ting; Chen, Jian-Qun

    2018-02-06

    To explore the effect and mechanism of artesunate on γδ T cell-mediated antitumor immune responses against hepatoma carcinoma cells (HepG2) in vitro. Human γδ T cells or HepG2 were respectively treated with artesunate, subjected to co-culture as appropriate, and the following assays were subsequently conducted: CCK8 to examine cell viability; LDH release assay to detect the killing effect of γδ T cells on HepG2 cells; flow cytometry to examine the expression of perforin (PFP) and granzyme B (GraB) of γδ T cells; ELISA to evaluate the levels of TGF-β1 and IL-10 in the collected supernatant of HepG2 cells pretreated with artesunate; and Western blot analysis to examine Fas, FasL, STAT3, p-STAT3 expression of HepG2 cells induced by artesunate.  Results: The results showed that the cytotoxicity effect of γδ T cells pretreated with artesunate on HepG2 cells was augmented via elevating the expression of GraB in γδ T cells. Furthermore, treatment with artesunate reversed the inhibition of HepG2 cells on γδ T cells by reducing the secretion of TGF-β1 in HepG2 cells supernatant and enhanced the antitumor effect of γδ T cells against HepG2 cells through increasing the expression of Fas on HepG2 cells, which may be attributed to the inhibition of STAT3 signaling protein. Artesunate has several mechanisms for augmenting the antitumor immune responses mediated by γδ T cells. These results suggested artesunate may be an efficacious agent in the treatment of hepatocellular carcinoma.

  19. Antiarrhythmic Amiodarone Mediates Apoptotic Cell Death of HepG2 Hepatoblastoma Cells through the Mitochondrial Pathway

    OpenAIRE

    Isomoto, Shojiro; Kawakami, Atsushi; Ohtsuru, Akira; Yamashita, Shunichi; Yano, Katsusuke

    2004-01-01

    The antiarrhythmic amiodarone is known to cause hepatic toxicity. Recently, much attention has been devoted to the role of apoptosis in the pathogenesis of drug-induced cytotoxicity. The aim of this study is to investigate whether apoptosis contributes to hepatic toxicity caused by amiodarone and, if so, by which mechanism. HepG2 human hepatoblastoma cells were incubated for 48 hours with various concentration of amiodarone. To determine apoptotic cells, concentration of cytochrome c in the c...

  20. Synergistic effect of nutlin-3 combined with aspirin in hepatocellular carcinoma HepG2 cells through activation of Bcl-2/Bax signaling pathway.

    Science.gov (United States)

    Miao, Runchen; Xu, Xinsen; Wang, Zhixin; Liu, Sushun; Qu, Kai; Chen, Wei; Liu, Chang

    2017-12-22

    aspirin by upregulating Bax expression in the HepG2 cell line and in vivo. The synergistic effect of nutlin‑3 in aspirin antitumor therapy contributed to diminishing the dose of aspirin required and decreased the occurrence of adverse drug events in HCC through targeting the Bcl‑2/Bax signaling pathway.

  1. Cytotoxicity and genotoxicity of stilbene derivatives in CHO-K1 and HepG2 cell lines

    Directory of Open Access Journals (Sweden)

    Cassia Suemi Mizuno

    2017-07-01

    Full Text Available Abstract The cytotoxicity and genotoxicity of the stilbenes (E-methyl-4-(3-5-dimethoxystyrylbenzoate (ester, (E-4-(3-5-dimethoxystyrylaniline (amino, (Z-1,3-dimethoxy-5-(4-methoxystyrylbenzene (cis-TMS and (E-1,3-dimethoxy-5-(4-methoxystyrylbenzene (trans-TMS were investigated in this work. Structural modifications of resveratrol, a naturally occurring stilbene, have been previously performed, including the replacement of hydroxyl by different functional groups. Such modifications resulted in significant improvement of target-specific effects on cell death and antiproliferative responses. The parameters were evaluated using XTT assay, clonogenic survival assay and the cytokinesis-block micronucleus assay in CHO-K1 and HepG2 cell lines. The results showed that cis-TMS is approximately 250-fold more cytotoxic than the amino and ester, and 128-fold more cytotoxic than trans-TMS. When genotoxicity was evaluated, only the trans-TMS did not significantly increase the frequency of micronucleus (MN. While the cis-TMS induced a mean of 5.2 and 5.9 MN/100 cells at 0.5 μM in CHO-K1 and HepG2, respectively, the amino and ester induced 3.1 and 3.6 MN/100 cells at 10 μM in CHO-K1, respectively, and 3.5 and 3.8 in HepG2. Trans-TMS is genotoxic only in HepG2 cells. Based on these results, the cis-TMS was the most cytotoxic and genotoxic compound in both cell lines.

  2. Newly developed chitosan-silver hybrid nanoparticles: biosafety and apoptosis induction in HepG2 cells

    Energy Technology Data Exchange (ETDEWEB)

    El-Sherbiny, Ibrahim M., E-mail: ielsherbiny@Zewailcity.edu.eg; Salih, Ehab [Zewail City of Science and Technology, Center for Materials Science (Egypt); Yassin, Abdelrahman M. [Genetic Engineering and Biotechnology Research Institute, City of Scientific Research and Technology Applications, Biopharmaceutical Product Research Department (Egypt); Hafez, Elsayed E. [City of Scientific Research and Technology Applications, Plant Protection and Biomolecular Diagnosis Department (Egypt)

    2016-07-15

    The present study reports the biosafety assessment, the exact molecular effects, and apoptosis induction of newly developed chitosan-silver hybrid nanoparticles (Cs–Ag NPs) in HepG2 cells. The investigated hybrid NPs were green synthesized using Cs/grape leaves aqueous extract (Cs/GLE) or Cs/GLE NPs as reducing and stabilizing agents. The successful formation of Cs/GLE NPs and Cs–Ag hybrid NPs has been confirmed by UV–Vis spectrophotometry, FTIR spectroscopy, XRD, and HRTEM. From the TEM analysis, the prepared Cs/GLE NPs are uniform and spherical with an average size of 150 nm, and the AgNPs (5–10 nm) were formed mainly on their surface. The UV–Vis spectra of Cs–Ag NPs showed a surface plasmon resonance (SPR) peak at about 450 nm confirming their formation. The synthesized Cs–Ag NPs were found to be crystalline as shown by XRD patterns with fcc phase oriented along the (111), (200), (220), and (311) planes. The cytotoxicity patterns, the antiproliferative activities, and the possible mechanisms of anticancer activity at molecular level of the newly developed Cs–Ag hybrid NPs were investigated. Cytotoxicity patterns of all the preparations demonstrated that the nontoxic treatment concentrations are ranged from 0.39 to 50 %, and many of the newly prepared Cs–Ag hybrid NPs showed high anticancer activities against HpG2 cells, and induced cellular apoptosis by downregulating BCL2 gene and upregulating P53.Graphical Abstract.

  3. Cytotoxic and apoptotic effects of six herbal plants against the human hepatocarcinoma (HepG2 cell line

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    Nonpunya Apiyada

    2011-10-01

    Full Text Available Abstract Background Six plants from Thailand were evaluated for their cytotoxicity and apoptosis induction in human hepatocarcinoma (HepG2 as compared to normal African green monkey kidney epithelial cell lines. Methods Ethanol-water crude extracts of the six plants were tested with neutral red assay for their cytotoxicity after 24 hours of exposure to the cells. Apoptotic induction was tested in the HepG2 cells with diamidino-2-phenylindole staining. DNA fragmentation, indicative of apoptosis, was analyzed with agarose gel electrophoresis. Alkylation, indicative of DNA damage, was also evaluated in vitro by 4-(4'-nitrobenzyl pyridine assay. Results The extract of Pinus kesiya showed the highest selectivity (selectivity index = 9.6 and potent cytotoxicity in the HepG2 cell line, with an IC50 value of 52.0 ± 5.8 μg/ml (mean ± standard deviation. Extract of Catimbium speciosum exerted cytotoxicity with an IC50 value of 55.7 ± 8.1 μg/ml. Crude extracts from Glochidion daltonii, Cladogynos orientalis, Acorus tatarinowii and Amomum villosum exhibited cytotoxicity with IC50 values ranging 100-500 μg/ml. All crude extracts showed different alkylating abilities in vitro. Extracts of P. kesiya, C. speciosum and C. orientalis caused nuclei morphological changes and DNA laddering. Conclusion The extracts of C. speciosum, C. orientalis and P. kesiya induced apoptosis. Among the three plants, P. kesiya possessed the most robust anticancer activity, with specific selectivity against HepG2 cells.

  4. Effects of Nano-CeO2 with Different Nanocrystal Morphologies on Cytotoxicity in HepG2 Cells

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    Lili Wang

    2015-09-01

    Full Text Available Cerium oxide nanoparticles (nano-CeO2 have been reported to cause damage and apoptosis in human primary hepatocytes. Here, we compared the toxicity of three types of nano-CeO2 with different nanocrystal morphologies (cube-, octahedron-, and rod-like crystals in human hepatocellular carcinoma cells (HepG2. The cells were treated with the nano-CeO2 at various concentrations (6.25, 12.5, 25, 50, 100 μg/mL. The crystal structure, size and morphology of nano-CeO2 were investigated by X-ray diffractometry and transmission electron microscopy. The specific surface area was detected using the Brunauer, Emmet and Teller method. The cellular morphological and internal structure were observed by microscopy; apoptotic alterations were measured using flow cytometry; nuclear DNA, mitochondrial membrane potential (MMP, reactive oxygen species (ROS and glutathione (GSH in HepG2 cells were measured using high content screening technology. The scavenging ability of hydroxyl free radicals and the redox properties of the nano-CeO2 were measured by square-wave voltammetry and temperature-programmed-reduction methods. All three types of nano-CeO2 entered the HepG2 cells, localized in the lysosome and cytoplasm, altered cellular shape, and caused cytotoxicity. The nano-CeO2 with smaller specific surface areas induced more apoptosis, caused an increase in MMP, ROS and GSH, and lowered the cell’s ability to scavenge hydroxyl free radicals and antioxidants. In this work, our data demonstrated that compared with cube-like and octahedron-like nano-CeO2, the rod-like nano-CeO2 has lowest toxicity to HepG2 cells owing to its larger specific surface areas.

  5. Protective effects of the extracts of Barringtonia racemosa shoots against oxidative damage in HepG2 cells

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    Kin Weng Kong

    2016-01-01

    Full Text Available Barringtonia racemosa is a tropical plant with medicinal values. In this study, the ability of the water extracts of the leaf (BLE and stem (BSE from the shoots to protect HepG2 cells against oxidative damage was studied. Five major polyphenolic compounds consisting of gallic acid, ellagic acid, protocatechuic acid, quercetin and kaempferol were identified using HPLC-DAD and ESI-MS. Cell viability assay revealed that BLE and BSE were non-cytotoxic (cell viabilities >80% at concentration less than 250 µg/ml and 500 µg/ml, respectively. BLE and BSE improved cellular antioxidant status measured by FRAP assay and protected HepG2 cells against H2O2-induced cytotoxicity. The extracts also inhibited lipid peroxidation in HepG2 cells as well as the production of reactive oxygen species. BLE and BSE could also suppress the activities of superoxide dismutase and catalase during oxidative stress. The shoots of B. racemosa can be an alternative bioactive ingredient in the prevention of oxidative damage.

  6. Upregulated copper transporters in hypoxia-induced pulmonary hypertension.

    Directory of Open Access Journals (Sweden)

    Adriana M Zimnicka

    Full Text Available Pulmonary vascular remodeling and increased arterial wall stiffness are two major causes for the elevated pulmonary vascular resistance and pulmonary arterial pressure in patients and animals with pulmonary hypertension. Cellular copper (Cu plays an important role in angiogenesis and extracellular matrix remodeling; increased Cu in vascular smooth muscle cells has been demonstrated to be associated with atherosclerosis and hypertension in animal experiments. In this study, we show that the Cu-uptake transporter 1, CTR1, and the Cu-efflux pump, ATP7A, were both upregulated in the lung tissues and pulmonary arteries of mice with hypoxia-induced pulmonary hypertension. Hypoxia also significantly increased expression and activity of lysyl oxidase (LOX, a Cu-dependent enzyme that causes crosslinks of collagen and elastin in the extracellular matrix. In vitro experiments show that exposure to hypoxia or treatment with cobalt (CoCl2 also increased protein expression of CTR1, ATP7A, and LOX in pulmonary arterial smooth muscle cells (PASMC. In PASMC exposed to hypoxia or treated with CoCl2, we also confirmed that the Cu transport is increased using 64Cu uptake assays. Furthermore, hypoxia increased both cell migration and proliferation in a Cu-dependent manner. Downregulation of hypoxia-inducible factor 1α (HIF-1α with siRNA significantly attenuated hypoxia-mediated upregulation of CTR1 mRNA. In summary, the data from this study indicate that increased Cu transportation due to upregulated CTR1 and ATP7A in pulmonary arteries and PASMC contributes to the development of hypoxia-induced pulmonary hypertension. The increased Cu uptake and elevated ATP7A also facilitate the increase in LOX activity and thus the increase in crosslink of extracellular matrix, and eventually leading to the increase in pulmonary arterial stiffness.

  7. Reduction of angiocidin contributes to decreased HepG2 cell ...

    African Journals Online (AJOL)

    Angiocidin protein production in HepG2 cells were reduced significantly by siRNA. When HepG2 cells were transfected with siRNA-angiocidin, these cells showed very low proliferation activity compared with control cells. Our study suggests that reduction of angiocidin may contribute to decreased proliferation activity in liver ...

  8. Polyphenols from the extract and fraction of T. indica seeds protected HepG2 cells against oxidative stress.

    Science.gov (United States)

    Razali, Nurhanani; Mat Junit, Sarni; Ariffin, Azhar; Ramli, Nur Siti Fatimah; Abdul Aziz, Azlina

    2015-12-18

    Tamarindus indica L. (T. indica) or locally known as "asam jawa" belongs to the family Leguminosae. T. indica seeds as by-products from the fruits were previously reported to contain high polyphenolic content. However, identification of their bioactive polyphenols using recent technologies is less well researched but nonetheless important. Hence, it was the aim of this study to provide further information on the polyphenolic content and antioxidant activities as well as to identify and quantify its bioactive polyphenols. T. indica seeds were extracted with methanol and were then fractionated with different compositions of hexane, ethyl acetate and methanol. Polyphenolic contents were measured using Folin-Ciocalteu assay while antioxidant activities were measured using DPPH radical scavenging and ferric reducing (FRAP) activities. The cytotoxic activities of the crude extract and the active fraction were evaluated in HepG2 cells using MTT assay. The cells were then pre-treated with the IC20 concentrations and induced with H2O2 before measuring their cellular antioxidant activities including FRAP, DPPH, lipid peroxidation, ROS generation and antioxidant enzymes, SOD, GPx and CAT. Analyses of polyphenols in the crude extract and its active fraction were done using UHPLC and NMR. Amongst the 7 isolated fractions, fraction F3 showed the highest polyphenolic content and antioxidant activities. When HepG2 cells were treated with fraction F3 or the crude extract, the former demonstrated higher antioxidant activities. F3 also showed stronger inhibition of lipid peroxidation and ROS generation, and enhanced activities of SOD, GPx and CAT of HepG2 cells following H2O2-induced oxidative damage. UHPLC analyses revealed the presence of catechin, procyanidin B2, caffeic acid, ferulic acid, chloramphenicol, myricetin, morin, quercetin, apigenin and kaempferol, in the crude seed extract of T. indica. UHPLC and NMR analyses identified the presence of caffeic acid in fraction F3. Our

  9. Effect of Recombinant Plasmid pEGFP-AFP-hTNF on Liver Cancer Cells (HepG2 Cells in vitro when Delivered by PEG-PEI/Fe3O4 Nanomagnetic Fluid

    Directory of Open Access Journals (Sweden)

    Baoxiong Zhuang

    2011-05-01

    Conclusion: PEG-PEI/Fe3O4 nanomagnetic fluid successfully transfected PEGFP-AFP-hTNFα into HepG2 cells and induced expression of hTNFα gene in the HepG2 cells, thus showing promise as a gene vector for liver cancer gene therapy. Furthermore, an AFP enhancer can specifically increase the expression of target genes in cells positive for AFP.

  10. Glyoxylate is a substrate of the sulfate-oxalate exchanger, sat-1, and increases its expression in HepG2 cells.

    Science.gov (United States)

    Schnedler, Nina; Burckhardt, Gerhard; Burckhardt, Birgitta C

    2011-03-01

    Hyperoxaluria is a major problem causing nephrolithiasis. Little is known about the regulation of oxalate transport from the liver, the main organ for oxalate synthesis, into the circulation. Since the sulfate anion transporter-1(sat-1) is present in the sinusoidal membrane of hepatocytes and translocates oxalate, its impact on increased oxalate synthesis was studied. Sat-1 expressing oocytes were used for cis-inhibition, trans-stimulation, and efflux experiments with labelled sulfate and oxalate to demonstrate the interactions of oxalate, glyoxylate, and glycolate with sat-1. HepG2 cells were incubated with oxalate and its precursors (glycine, hydroxyproline, glyoxylate, and glycolate). Changes in endogenous sat-1 mRNA-expression were examined using real-time PCR. After incubation of HepG2 cells in glyoxylate, sat-1 protein-expression was analysed by Western blotting, and sulfate uptake into HepG2 cells was measured. RT-PCR was used to screen for mRNA of other transporters. While oxalate and glyoxylate inhibited sulfate uptake, glycolate did not. Sulfate and oxalate uptake were trans-stimulated by glyoxylate but not by glycolate. Glyoxylate enhanced sulfate efflux. Glyoxylate was the only oxalate precursor stimulating sat-1 mRNA-expression. After incubation of HepG2 cells in glyoxylate, both sat-1 protein-expression and sulfate uptake into the cells increased. mRNA-expression of other transporters in HepG2 cells was not affected by glyoxylate treatment. The oxalate precursor glyoxylate was identified as a substrate of sat-1. Upregulated expression of sat-1 mRNA and of a functional sat-1 protein indicates that glyoxylate may be responsible for the elevated oxalate release from hepatocytes observed in hyperoxaluria. Copyright © 2010 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

  11. Involvement of endoplasmic reticulum and autophagy in microcystin-LR toxicity in Vero-E6 and HepG2 cell lines.

    Science.gov (United States)

    Menezes, Carina; Alverca, Elsa; Dias, Elsa; Sam-Bento, Filomena; Pereira, Paulo

    2013-02-01

    This work investigates the involvement of the endoplasmic reticulum (ER) and autophagy in microcystin-LR (MCLR) toxicity in Vero-E6 and HepG2 cell lines. Additionally, morphological alterations induced by MCLR in lysosomes and mitochondria were studied. Cytotoxicity evaluation showed that pure MCLR and MCLR from LMECYA110 extract induce concentration dependent viability decays after 24h exposure. HepG2 cells showed an increased sensitivity to MCLR than Vero cells, with lower cytotoxic thresholds and EC(50) values. Conversely, LC3B immunofluorescence showed that autophagy is triggered in both cell lines as a survival response to low MCLR concentrations. Furthermore, MCLR induced a MCLR concentration-dependent decrease of GRP94 expression in HepG2 cells while in Vero cells no alteration was observed. This suggests the involvement of the ER in HepG2 apoptosis elicited by MCLR, while in Vero cells ER destructuration could be a consequence of cytoskeleton inflicted damages. Additionally, in both cell lines, lysosomal destabilization preceded mitochondrial impairment which occurred at high toxin concentrations. Although not an early cellular target of MCLR, mitochondria appears to serve as central mediators of different signaling pathways elicited by the organelles involved in MCLR toxicity. As a result, kidney and hepatic cell lines exhibit cell type and dose-dependent mechanisms to overcome MCLR toxicity. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. β-Elemene Inhibits Cell Proliferation by Regulating the Expression and Activity of Topoisomerases I and IIα in Human Hepatocarcinoma HepG-2 Cells.

    Science.gov (United States)

    Gong, Min; Liu, Ying; Zhang, Jian; Gao, Ya-jie; Zhai, Ping-ping; Su, Xi; Li, Xiang; Li, Yan; Hou, Li; Cui, Xiao-nan

    2015-01-01

    To investigate the effects of β-Elemene (β-ELE) on the proliferation, apoptosis, and topoisomerase I (TOPO I) and topoisomerase IIα (TOPO IIα) expression and activity of human hepatocarcinoma HepG-2 cells. After treatment with β-ELE, morphological alterations of HepG-2 cells were observed under an inverted microscope. Cell proliferation was assessed using an MTT assay, cell cycles were analyzed using flow cytometry, and apoptosis was detected by Annexin V/PI staining. The expression of TOPO I and TOPO IIα was analyzed by Western blot techniques, and their activity was measured using the TOPO I-mediated, supercoiled pBR322 DNA relaxation and TOPO IIα-mediated Kinetoplast DNA (kDNA) decatenation assays, respectively. Supercoiled pBR322 and kDNA were also used to determine the direct effect of β-ELE on DNA breaks. β-ELE significantly inhibited HepG-2 cell proliferation in a dose- and time-dependent manner. β-ELE also induced tumor cell arrest at S phase, induced cell apoptosis, and downregulated the protein expression of TOPO I and TOPO IIα in a dose-dependent manner. β-ELE also inhibited TOPO I- and TOPO IIα-mediated DNA relaxation but did not directly induce DNA breakage at any concentration. β-ELE could inhibit the proliferation of HepG-2 cells and interfere with the expression and activity of TOPO I and TOPO IIα.

  13. Induction of apoptosis in HepG2 cells by polysaccharide MEP-II from the fermentation broth of Morchella esculenta.

    Science.gov (United States)

    Hu, Meili; Chen, Yan; Wang, Cui; Cui, Huali; Duan, Peilu; Zhai, Tianlong; Yang, Yuling; Li, Shaofei

    2013-01-01

    A novel polysaccharide, MEP-II, isolated from the fermentation broth of Morchella esculenta inhibited the proliferation of human hepatoma cell line (HepG2) through an apoptotic pathway. After HepG2 cells were treated with 150-600 μg MEP-II/ml, typical apoptotic characteristics including externalization of phosphatidylserine residues on the cell surface, nuclear fragmentation, chromatin condensation and cytoplasm shrinkage were observed. Furthermore, reactive oxygen species (ROS) burst and the collapse of mitochondrial membrane potential (Δψm) also occurred in HepG2 cells after incubation of 150-600 μg MEP-II/ml. The antioxidant, 1 mM N-acetyl-L-cysteine inhibited MEP-II-induced apoptosis, suggesting that ROS are the key mediators for MEP-II-induced apoptosis. MEP-II is therefore a potential anti-tumor agent that induces apoptosis of HepG2 cells through ROS generation.

  14. Free radical generation from an aniline derivative in HepG2 cells: a possible captodative effect.

    Science.gov (United States)

    Horinouchi, Yuya; Summers, Fiona A; Ehrenshaft, Marilyn; Mason, Ronald P

    2015-01-01

    Xenobiotic metabolism can induce the generation of protein radicals, which are believed to play an important role in the toxicity of chemicals and drugs. It is therefore important to identify chemical structures capable of inducing macromolecular free radical formation in living cells. In this study, we evaluated the ability of four structurally related environmental chemicals, aniline, nitrosobenzene, N,N-dimethylaniline, and N,N-dimethyl-4-nitrosoaniline (DMNA), to induce free radicals and cellular damage in the hepatoma cell line HepG2. Cytotoxicity was assessed using lactate dehydrogenase assays, and morphological changes were observed using phase contrast microscopy. Protein free radicals were detected by immuno-spin trapping using in-cell western experiments and confocal microscopy to determine the subcellular locale of free radical generation. DMNA induced free radical generation, lactate dehydrogenase release, and morphological changes in HepG2 cells, whereas aniline, nitrosobenzene, N,N-dimethylaniline did not. Confocal microscopy showed that DMNA induced free radical generation mainly in the cytosol. Preincubation of HepG2 cells with N-acetylcysteine and 2,2'-dipyridyl significantly prevented free radical generation on subsequent incubation with DMNA, whereas preincubation with apocynin and dimethyl sulfoxide had no effect. These results suggest that DMNA is metabolized to reactive free radicals capable of generating protein radicals which may play a critical role in DMNA toxicity. We propose that the captodative effect, the combined action of the electron-releasing dimethylamine substituent, and the electron-withdrawing nitroso substituent, leads to a thermodynamically stabilized radical, facilitating enhanced protein radical formation by DMNA. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Docosahexanoic acid modifies low-density lipoprotein receptor abundance in HepG2 cells via suppression of the LXRα-Idol pathway.

    Science.gov (United States)

    Zhou, Ying; Guo, Yue; Zhuang, Xiaodong; Du, Zhimin

    2015-03-01

    As a daily supplement, omega‑3 fatty acid is confirmed to be of benefit in hypertriglyceridemia. However, the effect of omega‑3 fatty acids on the low‑density lipoprotein cholesterol (LDL‑C) metabolism remains a controversial issue. In this study, we focused on the regulatory effect of docosahexanoic acid (DHA), one type of omega‑3 fatty acid, exerted on the LDL receptor (LDLR), a determinant regulator of the LDL‑C metabolism, and explored the potential mechanism. We observed that DHA increased hepatic LDLR protein in the presence of 25‑hydroxycholesterol in HepG2 cells but did not alter the mRNA level. Previous studies have identified inducible degrader of the LDLR (Idol) as a novel negative post‑translational modulator of LDLR and a direct transcriptional target of liver X receptor α (LXRα). Since DHA had no effect on the transcriptional level of LDLR, we speculated that the post‑transcriptional pathway LXRα‑Idol participated in this regulation. The results reveal that DHA downregulated the expression of LXRα and Idol in coordination with the upregulation of LDLR expression. Multiple mechanisms are involved in the regulation of LDLR by DHA, and the suppression of the LXRα‑Idol pathway is one of these mechanisms.

  16. In vitro investigations of Cynara scolymus L. extract on cell physiology of HepG2 liver cells

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    Gesine Löhr

    2009-06-01

    Full Text Available The objective of this study was the investigation of a potential influence of artichoke leaf extract (ALE on the cell physiology and gene expression of phase I/II enzymes of human liver cells HepG2 and investigation on potential cell protective effects against ethanol-induced cell toxicity against HepG2 cells. Cell biological assays under in vitro conditions using HepG2 liver cells and investigation of mitochondrial activity (MTT test, proliferation assay (BrdU incorporation ELISA, LDH as toxicity marker, gene expression analysis by RT-PCR and enzyme activity of glutationtransferase. Artichocke extract, containing 27% caffeoylquinic acids and 7% flavonoids induced mitochondrial activity, proliferation and total protein content under in vitro conditions in human liver cells HepG2. These effects could not be correlated to the well-known artichoke secondary compounds cynarin, caffeic acid, chlorogenic acid, luteolin and luteolin-7-O-glucoside. The flavones luteolin and luteolin-7-O-glucoside had inhibitory effects at 100 µg/mL level on HepG2 cells, with luteolin being a significant stronger inhibitor compared to the respective glucoside. Artichoke leaf extract had minor stimulating effect on gene expression of CYP1A2, while CYP3A4, GGT, GPX2, GSR and GST were slightly inhibited. GST inhibition under in vitro conditions was also shown by quantification of GST enzyme activity. Induction of gene expression of CYP1A2 was shown to be supraadditive after simultaneous application of ethanol plus artichoke extract. Artichoke leaf extract exhibited cell protective effects against ethanol-induced toxicity within cotreatment under in vitro conditions. Also H2O2 damage was significantly inhibited by simultaneous artichoke incubation. Pre- and posttreatments did not exert protective effects. DMSO-induced toxicity was significantly reduced by pre-, post- and cotreatment with artichoke extract and especially with luteolin-7-O-glucoside, indicating a direct

  17. A Novel Exploration of a Combination of Gambogic Acid with TiO2 Nanofibers: The Photodynamic Effect for HepG2 Cell Proliferation

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    Jingyuan Li

    2014-09-01

    Full Text Available As a good photosensitizer, TiO2 nanomaterials show potential biomedical applications, such as drug carriers or enhancers in photodynamic therapy. In this contribution, novel nanocomposites through the blending of TiO2 nanofibers with the active compound, gambogic acid (GA, were explored, and the results showed that GA could inhibit cancer cell proliferation in a time-dependent and dose-dependent manner, inducing apoptosis and cell cycle arrest at the G0/G1 phase in HepG2 cells. It is evident that after the GA-TiO2 nanocomposites were cultured with the cancer cells, the cooperation effect could effectively enhance the cytotoxicity of GA for HepG2 cells. Meanwhile, if activated by UV irradiation, under the presence of GA-TiO2 nanocomposites, this would lead to significant apoptosis and necrosis for HepG2 cells with a photodynamic therapy (PDT effect. Associated with the controlled drug-release from these nanocomposites, TiO2 nanofibers could readily cut down the drug consumption in HepG2 cells and reduce the side-effect for the normal cells and tissue, which may be further utilized in the therapeutic alliance for cancer therapy.

  18. A 3D in vitro model of differentiated HepG2 cell spheroids with improved liver-like properties for repeated dose high-throughput toxicity studies.

    Science.gov (United States)

    Ramaiahgari, Sreenivasa C; den Braver, Michiel W; Herpers, Bram; Terpstra, Valeska; Commandeur, Jan N M; van de Water, Bob; Price, Leo S

    2014-05-01

    Immortalized hepatocyte cell lines show only a weak resemblance to primary hepatocytes in terms of gene expression and function, limiting their value in predicting drug-induced liver injury (DILI). Furthermore, primary hepatocytes cultured on two-dimensional tissue culture plastic surfaces rapidly dedifferentiate losing their hepatocyte functions and metabolic competence. We have developed a three-dimensional in vitro model using extracellular matrix-based hydrogel for long-term culture of the human hepatoma cell line HepG2. HepG2 cells cultured in this model stop proliferating, self-organize and differentiate to form multiple polarized spheroids. These spheroids re-acquire lost hepatocyte functions such as storage of glycogen, transport of bile salts and the formation of structures resembling bile canaliculi. HepG2 spheroids also show increased expression of albumin, urea, xenobiotic transcription factors, phase I and II drug metabolism enzymes and transporters. Consistent with this, cytochrome P450-mediated metabolism is significantly higher in HepG2 spheroids compared to monolayer cultures. This highly differentiated phenotype can be maintained in 384-well microtiter plates for at least 28 days. Toxicity assessment studies with this model showed an increased sensitivity in identifying hepatotoxic compounds with repeated dosing regimens. This simple and robust high-throughput-compatible methodology may have potential for use in toxicity screening assays and mechanistic studies and may represent an alternative to animal models for studying DILI.

  19. Inhibition of MEK/ERK1/2 Signaling Affects the Fatty Acid Composition of HepG2 Human Hepatic Cell Line

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    Bahman Yousefi

    2012-06-01

    Full Text Available Introduction: The extracellular signal-regulated kinase (ERK mitogen-activated protein kinase pathway, also known as the MEK/ERK1/2 kinase cascade, has recently been implicated in the regulation of lipid metabolism and fatty liver disease. However, its functional effect on cellular fatty acid composition is unknown. Herein, we examined the effect of a pharmacological inhibitor of MEK, the upstream kinase activator of ERK1/2, on fatty acid composition of hepatocellular carcinoma cell line HepG2. Methods: HepG2 cells cultured in RPMI-1640 were exposed to the commonly used ERK1/2 pathway inhibitor PD98059 and were investigated with respect to fatty acid composition by gas-liquid chromatography. Results: Exposure of cells to the ERK1/2 pathway inhibitor induced an increase in monounsaturated fatty acids and the fatty acid desaturation index and a decrease in polyunsaturated fatty acid content. Specifically, we showed a significant increase of oleic acid (18:1n‑9; +29%, P=0.003 and arachidonic acid (20:4n‑6/linoleic acid (18:2n‑6 ratio (3.5-fold; P<0.001 in HepG2 cells. Conclusion: Cellular fatty acid composition of HepG2 cells appeared to be differentially regulated by ERK1/2 pathway, thus suggesting related metabolic pathways as potential mediators of the effects of ERK1/2 signaling on hepatic fatty acid composition.

  20. Gelsolin negatively regulates the activity of tumor suppressor p53 through their physical interaction in hepatocarcinoma HepG2 cells

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    An, Joo-Hee; Kim, Jung-Woong; Jang, Sang-Min; Kim, Chul-Hong; Kang, Eun-Jin; Choi, Kyung-Hee, E-mail: khchoi@cau.ac.kr

    2011-08-19

    Highlights: {yields} The actin binding protein Gelsolin (GSN) interacts with transcription factor p53. {yields} GSN interacts with transactivation- and DNA binding domains of p53. {yields} GSN represses transactivity of p53 via inhibition of nuclear translocation of p53. {yields} GSN inhibits the p53-mediated apoptosis in hepatocarcinoma HepG2 cells. -- Abstract: As a transcription factor, p53 modulates several cellular responses including cell-cycle control, apoptosis, and differentiation. In this study, we have shown that an actin regulatory protein, gelsolin (GSN), can physically interact with p53. The nuclear localization of p53 is inhibited by GSN overexpression in hepatocarcinoma HepG2 cells. Additionally, we demonstrate that GSN negatively regulates p53-dependent transcriptional activity of a reporter construct, driven by the p21-promoter. Furthermore, p53-mediated apoptosis was repressed in GSN-transfected HepG2 cells. Taken together, these results suggest that GSN binds to p53 and this interaction leads to the inhibition of p53-induced apoptosis by anchoring of p53 in the cytoplasm in HepG2 cells.

  1. Effect of bixin and norbixin on the expression of cytochrome P450 in HepG2 cell line.

    Science.gov (United States)

    Matuo, Míriam Cristina Sakuragui; de Oliveira Takamoto, Rafael Teruiti; Kikuchi, Irene Satiko; de Jesus Andreoli Pinto, Terezinha

    2013-08-01

    Bixin and norbixin are the main components of annatto, which is extracted from Bixa orellana and largely used as natural colorant in the food and pharmaceutical industries. Annatto can enhance CYP1A and CYP2B activity in rats; however, the inducer effect has not been investigated in human cell lines. In this study, the ability of bixin and norbixin to induce the cytochrome P450 (CYP) enzymes was assessed in HepG2 human hepatoma cell line. HepG2 cells were treated with bixin and norbixin, and the expression of the CYP genes quantified by real-time reverse transcription polymerase chain reaction (RT-PCR). Expression of CYP1A1 and CYP1A2 was significantly increased by bixin treatment, while CYP2B6, 2C9, 2E1 and 3A4 were unaffected. Cells were treated with norbixin showed no inducer effect. The results suggest that the inducer potential of annatto is attributed to bixin, but not to norbixin, despite their similarities in molecular structure. © 2013 International Federation for Cell Biology.

  2. Cholesterol lowering effects of mono-lactose-appended β-cyclodextrin in Niemann–Pick type C disease-like HepG2 cells

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    Keiichi Motoyama

    2015-11-01

    Full Text Available The Niemann–Pick type C disease (NPC is one of inherited lysosomal storage disorders, emerges the accumulation of unesterified cholesterol in endolysosomes. Currently, 2-hydroxypropyl-β-cyclodextrin (HP-β-CyD has been applied for the treatment of NPC. HP-β-CyD improved hepatosplenomegaly in NPC patients, however, a high dose of HP-β-CyD was necessary. Therefore, the decrease in dose by actively targeted-β-CyD to hepatocytes is expected. In the present study, to deliver β-CyD selectively to hepatocytes, we newly fabricated mono-lactose-appended β-CyD (Lac-β-CyD and evaluated its cholesterol lowering effects in NPC-like HepG2 cells, cholesterol accumulated HepG2 cells induced by treatment with U18666A. Lac-β-CyD (degree of substitution of lactose (DSL 1 significantly decreased the intracellular cholesterol content in a concentration-dependent manner. TRITC-Lac-β-CyD was associated with NPC-like HepG2 cells higher than TRITC-β-CyD. In addition, TRITC-Lac-β-CyD was partially localized with endolysosomes after endocytosis. Thus, Lac-β-CyD entered NPC-like HepG2 cells via asialoglycoprotein receptor (ASGPR-mediated endocytosis and decreased the accumulation of intracellular cholesterol in NPC-like HepG2 cells. These results suggest that Lac-β-CyD may have the potential as a drug for the treatment of hepatosplenomegaly in NPC disease.

  3. Effect of solanine on the membrane potential of mitochondria in HepG2 cells and [Ca2+]i in the cells.

    Science.gov (United States)

    Gao, Shi-Yong; Wang, Qiu-Juan; Ji, Yu-Bin

    2006-06-07

    To observe the effect of solanine on the membrane potential of mitochondria in HepG(2) cells and [Ca(2+)](i) in the cells, and to uncover the mechanism by which solanine induces apoptosis. HepG(2) cells were double stained with AO/EB, and morphological changes of the cells were observed using laser confocal scanning microscopy (LCSM). HepG(2) cells were stained with TMRE, and change in the membrane potential of mitochondria in the cells were observed using LCSM. HepG(2) cells were double stained with Fluo-3/AM, and change of [Ca(2+)](i) in the cells were observed using LCSM. HepG(2) cells were double stained with TMRE and Fluo-3/AM, and both the change in membrane potential of mitochondria and that of [Ca(2+)](i) in the cells were observed using LCSM. Cells in treated groups showed typical signs of apoptosis. Staining with TMRE showed that solanine could lower membrane potential; staining with Fluo-3/AM showed that solanine could increase the concentration of Ca(2+) in tumor cells; and those of double staining with TMRE and Fluo-3/AM showed that solanine could increase the concentration of Ca(2+) in the cells at the same time as it lowered the membrane potential of mitochondria. Solanine opens up the PT channels in the membrane by lowering the membrane po-tential, leading to Ca(2+) being transported down its concentration gradient, which in turn leads to the rise of the concentration of Ca(2+) in the cell, turning on the mechanism for apoptosis.

  4. Apoptosis Induction by Polygonum minus Is Related to Antioxidant Capacity, Alterations in Expression of Apoptotic-Related Genes, and S-Phase Cell Cycle Arrest in HepG2 Cell Line

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    Mohd Alfazari Mohd Ghazali

    2014-01-01

    Full Text Available Polygonum minus (Polygonaceae is a medicinal herb distributed throughout eastern Asia. The present study investigated antiproliferative effect of P. minus and its possible mechanisms. Four extracts (petroleum ether, methanol, ethyl acetate, and water were prepared by cold maceration. Extracts were subjected to phytochemical screening, antioxidant, and antiproliferative assays; the most bioactive was fractionated using vacuum liquid chromatography into seven fractions (F1–F7. Antioxidant activity was measured via total phenolic content (TPC, 2,2-diphenyl-1-picrylhydrazyl (DPPH, and ferric reducing antioxidant power (FRAP assays. Antiproliferative activity was evaluated using 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay. Most active fraction was tested for apoptosis induction and cell cycle arrest in HepG2 cells using flow cytometry and confocal microscopy. Apoptotic-related gene expression was studied by RT-PCR. Ethyl acetate extract was bioactive in initial assays. Its fraction, F7, exhibited highest antioxidant capacity (TPC; 113.16±6.2 mg GAE/g extract, DPPH; EC50: 30.5±3.2 μg/mL, FRAP; 1169±20.3 μmol Fe (II/mg extract and selective antiproliferative effect (IC50: 25.75±1.5 μg/mL. F7 induced apoptosis in concentration- and time-dependent manner and caused cell cycle arrest at S-phase. Upregulation of proapoptotic genes (Bax, p53, and caspase-3 and downregulation of antiapoptotic gene, Bcl-2, were observed. In conclusion, F7 was antiproliferative to HepG2 cells by inducing apoptosis, cell cycle arrest, and via antioxidative effects.

  5. Apoptosis Induction by Polygonum minus Is Related to Antioxidant Capacity, Alterations in Expression of Apoptotic-Related Genes, and S-Phase Cell Cycle Arrest in HepG2 Cell Line

    Science.gov (United States)

    Mohd Ghazali, Mohd Alfazari; Al-Naqeb, Ghanya; Krishnan Selvarajan, Kesavanarayanan; Hazizul Hasan, Mizaton; Adam, Aishah

    2014-01-01

    Polygonum minus (Polygonaceae) is a medicinal herb distributed throughout eastern Asia. The present study investigated antiproliferative effect of P. minus and its possible mechanisms. Four extracts (petroleum ether, methanol, ethyl acetate, and water) were prepared by cold maceration. Extracts were subjected to phytochemical screening, antioxidant, and antiproliferative assays; the most bioactive was fractionated using vacuum liquid chromatography into seven fractions (F1–F7). Antioxidant activity was measured via total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP) assays. Antiproliferative activity was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Most active fraction was tested for apoptosis induction and cell cycle arrest in HepG2 cells using flow cytometry and confocal microscopy. Apoptotic-related gene expression was studied by RT-PCR. Ethyl acetate extract was bioactive in initial assays. Its fraction, F7, exhibited highest antioxidant capacity (TPC; 113.16 ± 6.2 mg GAE/g extract, DPPH; EC50: 30.5 ± 3.2 μg/mL, FRAP; 1169 ± 20.3 μmol Fe (II)/mg extract) and selective antiproliferative effect (IC50: 25.75 ± 1.5 μg/mL). F7 induced apoptosis in concentration- and time-dependent manner and caused cell cycle arrest at S-phase. Upregulation of proapoptotic genes (Bax, p53, and caspase-3) and downregulation of antiapoptotic gene, Bcl-2, were observed. In conclusion, F7 was antiproliferative to HepG2 cells by inducing apoptosis, cell cycle arrest, and via antioxidative effects. PMID:24955361

  6. Ursolic acid sensitizes cisplatin-resistant HepG2/DDP cells to cisplatin via inhibiting Nrf2/ARE pathway

    Directory of Open Access Journals (Sweden)

    Wu S

    2016-10-01

    Full Text Available Shouhai Wu,1,2 Tianpeng Zhang,1 Jingsheng Du3 1School of Life Sciences, Sun Yat-sen University, 2Center for Regenerative and Translational Medicine, 3Department of Pharmacy, The Second Affiliated Hospital, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People’s Republic of China Background: Combinations of adjuvant sensitizers with anticancer drugs is a promising new strategy to reverse chemoresistance. Ursolic acid (UA is one of the natural pentacyclic triterpene compounds known to have many pharmacological characteristics such as anti-inflammatory and anticancer properties. This study investigates whether UA can sensitize hepatocellular carcinoma cells to cisplatin.Materials and methods: Cells were transfected with nuclear factor erythroid-2-related factor 2 (Nrf2 small interfering RNA and Nrf2 complementary DNA by using Lipofectin 2000. The cytotoxicity of cells was investigated by Cell Counting Kit 8 assay. Cell apoptosis, cell cycle, reactive oxygen species, and mitochondrial membrane potential were detected by flow cytometry fluorescence-activated cell sorting. The protein level of Nrf2, NAD(PH quinone oxidoreductase 1 (NQO1, glutathione S-transferase (GST, and heme oxygenase-1 (HO-1 was detected by Western blot analysis.Results: The results showed that the reverse index was 2.9- and 9.69-fold by UA of 1.125 µg/mL and 2.25 µg/mL, respectively, for cisplatin to HepG2/DDP cells. UA–cisplatin combination induced cell apoptosis and reactive oxygen species, blocked the cell cycle in G0/G1 phase, and reduced the mitochondrial membrane potential. Mechanistically, UA–cisplatin dramatically decreased the expression of Nrf2 and its downstream genes. The sensibilization of UA–cisplatin combination was diminished in Nrf2 small interfering RNA-transfected HepG2/DDP cells, as well as in Nrf2 complementary DNA-transfected HepG2/DDP cells.Conclusion: The results confirmed the sensibilization of UA on HepG2/DDP cells to

  7. Transcriptome Analysis of HepG2 Cells Expressing ORF3 from Swine Hepatitis E Virus to Determine the Effects of ORF3 on Host Cells

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    Kailian Xu

    2016-01-01

    Full Text Available Hepatitis E virus- (HEV- mediated hepatitis has become a global public health problem. An important regulatory protein of HEV, ORF3, influences multiple signal pathways in host cells. In this study, to investigate the function of ORF3 from the swine form of HEV (SHEV, high-throughput RNA-Seq-based screening was performed to identify the differentially expressed genes in ORF3-expressing HepG2 cells. The results were validated with quantitative real-time PCR and gene ontology was employed to assign differentially expressed genes to functional categories. The results indicated that, in the established ORF3-expressing HepG2 cells, the mRNA levels of CLDN6, YLPM1, APOC3, NLRP1, SCARA3, FGA, FGG, FGB, and FREM1 were upregulated, whereas the mRNA levels of SLC2A3, DKK1, BPIFB2, and PTGR1 were downregulated. The deregulated expression of CLDN6 and FREM1 might contribute to changes in integral membrane protein and basement membrane protein expression, expression changes for NLRP1 might affect the apoptosis of HepG2 cells, and the altered expression of APOC3, SCARA3, and DKK1 may affect lipid metabolism in HepG2 cells. In conclusion, ORF3 plays a functional role in virus-cell interactions by affecting the expression of integral membrane protein and basement membrane proteins and by altering the process of apoptosis and lipid metabolism in host cells. These findings provide important insight into the pathogenic mechanism of HEV.

  8. [The influence of doxorubicin incorporated in phospholipid drug delivery nanosystem on HEPG2 cells proteome].

    Science.gov (United States)

    Kuznetzova, K G; Kazlas, E V; Torkhovskaya, T I; Karalkin, P A; Vachrushev, I V; Zakharova, T S; Sanzhakov, M A; Moshkovskiy, S A; Ipatova, O M

    2015-01-01

    A phospholipid drug delivery nanosystem with particle size up to 30 nm elaborated at the Institute of Biomedical Chemistry has been used earlier for incorporation of doxorubicin (Doxolip). This system demonstrated higher antitumor effect in vivo as compared with free doxorubicin. In this study the effect of this nanosystem containing doxorubicin on HepG2 cell proteome has been investigated. Cells were incubated in a medium containing phospholipid nanoparticles (0.5 mg/ml doxorubicin, 10 mg/mL phosphatidylcholine). After incubation for 48 h their survival represented 10% as compared with untreated cells. Cell proteins were analyzed by quantitative two-dimensional gel electrophoresis followed by identification of differentially expressed proteins with MALDI-TOF mass spectrometry. The phospholipid transport nanosystem itself insignificantly influenced the cell proteome thus confirming previous data on its safety. Doxorubicin, as both free substance and Doxolip (i.e. included into phospholipid nanoparticles) induced changes in expression of 28 proteins. Among these proteins only four of them demonstrated different in response to the effect of the free drug substance and Doxolip. Doxolip exhibited a more pronounced effect on expression of certain proteins; the latter indirectly implies increased penetration of the drug substance (included into nanoparticles) into the tumor cells. Increased antitumor activity of doxorubicin included into phospholipid nanoparticles may be associated with more active increase of specific protein expression.

  9. Upregulation of lysyl oxidase expression in cyclosporin A-induced gingival overgrowth

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    Chung-Hung Tsai

    2009-03-01

    Conclusion: LOX expression was significantly upregulated in CsA-induced gingival overgrowth specimens. In addition, the expression of LOX increased with the grade of inflammation in CsA-induced gingival overgrowth.

  10. Flavonoids from Enicostema littorale blume enhances glucose uptake of cells in insulin resistant human liver cancer (HepG2) cell line via IRS-1/PI3K/Akt pathway.

    Science.gov (United States)

    Mokashi, Priyanka; Khanna, Aparna; Pandita, Nancy

    2017-06-01

    Diabetes mellitus has spread over the world with 347 million people affected. Insulin resistance is a main pathogenic event in Type 2 Diabetes Mellitus (T2DM) leading to a reduction in glucose uptake by peripheral tissue and increased hepatic glucose output. In this study, we have isolated four flavonoid rich fractions fraction A (FA), fraction B (FB), fraction C (FC) and fraction D (FD) from Enicostema littorale. All the fractions were preliminary screened for TLC fingerprinting, total flavonoid content. Total eight flavonoids were identified by LC/MS. Insulin resistant HepG2 (IR/HepG2) model was established by inducing insulin resistance in HepG2 cells to investigate the effect of these fractions on IR/HepG2 cell line for their glucose uptake. The results showed the significant dose dependant increase in glucose uptake of cells treated with FD. It showed significant activity at a concentration of 10μg/ml. The LC/MS results of FD demonstrated the presence of C-glycoside Swertisin which could be responsible for the effect. Further, to investigate the mechanism of action, gene expression for insulin receptor substrate 1 (IRS-1), protein kinase B (Akt-2) and glucose transporter 4 (GLUT-4) genes were evaluated by real time PCR. A significant upregulation of these genes was observed in FD treated samples, thereby indicating the enhancement of glucose uptake rate of cells via IRS-1/PI3K/Akt pathway. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  11. ANTIPROLIFERATIVE AND APOPTOTIC EFFECTS OF THE ESSENTIAL OIL OF ORIGANUM ONITES AND CARVACROL ON HEP-G2 CELLS

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    Özlem TOMSUK

    2011-08-01

    Full Text Available The essential oil Origanum onites L. and its phenolic constituent carvacrol were examined for their cytotoxic and apoptotic effects in a human hepatocellular carcinoma cells Hep-G2. WST-1 and neutral red uptake assays were performed to determine the inhibitory effects of the oil and carvacrol on the growth of the cells. Possible induction of apoptosis by Origanum oil and carvacrol was further investigated by acridine orange/ethidium bromide (AO/EB staining. Results showed that the Ori- ganum oil and carvacrol was significantly cytotoxic and induced apoptosis in Hep-G2 cells. IC₅₀ value of essential oil and carvacrol was found about 0,009% (v/v and 500 μM, respectively. After incuba- tion of the cells with Origanum oil and carvacrol, characteristics of apoptotic morphology such as chromatin condensation, shrinkage of the cells and cytoplasmic blebbing was observed. In conclusion, both essential oil and its major constituent carvacrol significantly exhibited cytotoxic and apoptotic activities in hepatocellular carcinoma cells, indicating its potential for use as an anticancer agent.

  12. Dose-Dependent Cytotoxic Effects of Boldine in HepG-2 Cells—Telomerase Inhibition and Apoptosis Induction

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    Sakineh Kazemi Noureini

    2015-02-01

    Full Text Available Plant metabolites are valuable sources of novel therapeutic compounds. In an anti-telomerase screening study of plant secondary metabolites, the aporphine alkaloid boldine (1,10-dimethoxy-2,9-dihydroxyaporphine exhibited a dose and time dependent cytotoxicity against hepatocarcinoma HepG-2 cells. Here we focus on the modes and mechanisms of the growth-limiting effects of this compound. Telomerase activity and expression level of some related genes were estimated by real-time PCR. Modes of cell death also were examined by microscopic inspection, staining methods and by evaluating the expression level of some critically relevant genes. The growth inhibition was correlated with down-regulation of the catalytic subunit of telomerase (hTERT gene (p < 0.01 and the corresponding reduction of telomerase activity in sub-cytotoxic concentrations of boldine (p < 0.002. However, various modes of cell death were stimulated, depending on the concentration of boldine. Very low concentrations of boldine over a few passages resulted in an accumulation of senescent cells so that HepG-2 cells lost their immortality. Moreover, boldine induced apoptosis concomitantly with increasing the expression of bax/bcl2 (p < 0.02 and p21 (p < 0.01 genes. Boldine might thus be an interesting candidate as a potential natural compound that suppresses telomerase activity in non-toxic concentrations.

  13. Erythrosine B and quinoline yellow dyes regulate DNA repair gene expression in human HepG2 cells.

    Science.gov (United States)

    Chequer, Farah Md; Venancio, Vinicius P; Almeida, Mara R; Aissa, Alexandre F; Bianchi, Maria Lourdes P; Antunes, Lusânia Mg

    2017-10-01

    Erythrosine B (ErB) is a cherry pink food colorant and is widely used in foods, drugs, and cosmetics. Quinoline yellow (QY) is a chinophthalon derivative used in cosmetic compositions for application to the skin, lips, and/or body surface. Previously, ErB and QY synthetic dyes were found to induce DNA damage in HepG2 cells. The aim of this study was to investigate the molecular basis underlying the genotoxicity attributed to ErB and QY using the RT2 Profiler polymerase chain reaction array and by analyzing the expression profile of 84 genes involved in cell cycle arrest, apoptosis, and DNA repair in HepG2 cells. ErB (70 mg/L) significantly decreased the expression of two genes ( FEN1 and REV1) related to DNA base repair. One gene ( LIG1) was downregulated and 20 genes related to ATR/ATM signaling ( ATR, RBBP8, RAD1, CHEK1, CHEK2, TOPB1), nucleotide excision repair ( ERCC1, XPA), base excision repair ( FEN1, MBD4), mismatch repair ( MLH1, MSH3, TP73), double strand break repair ( BLM), other DNA repair genes ( BRIP1, FANCA, GADD45A, REV1), and apoptosis ( BAX, PPP1R15A) were significantly increased after treatment with QY (20 mg/L). In conclusion, our data suggest that the genotoxic mechanism of ErB and QY dyes involves the modulation of genes related to the DNA repair system and cell cycle.

  14. Targeting and molecular imaging of HepG2 cells using surface-functionalized gold nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Rathinaraj, Pierson [Auckland University of Technology, Institute of Biomedical Technologies (New Zealand); Lee, Kyubae; Choi, Yuri; Park, Soo-Young [Kyungpook National University, School of Applied Chemical Engineering, Graduate School (Korea, Republic of); Kwon, Oh Hyeong [Kumoh National Institute of Technology, Department of Polymer Science and Engineering (Korea, Republic of); Kang, Inn-Kyu, E-mail: ikkang@knu.ac.kr [Kyungpook National University, School of Applied Chemical Engineering, Graduate School (Korea, Republic of)

    2015-07-15

    Mercaptosuccinic acid (M)-conjugated gold nanoparticles (GM) were prepared and characterized by transmission electron microscope and dynamic light scattering. M was used to improve the monodispersity and non-specific intracellular uptake of nanoparticles. Lactobionic acid (L) was subsequently conjugated to the GM to target preferentially HepG2 cells (liver cancer cells) that express asialoglycoprotein receptors (ASGPR) on their membrane surfaces and facilitate the transit of nanoparticles across the cell membrane. The mean size of lactobionic acid-conjugated gold nanoparticle (GL) was approximately 10 ± 0.2 nm. Finally, the Atto 680 dye (A6) was coupled to the nanoparticles to visualize their internalization into HepG2 cells. The interaction of surface-modified gold nanoparticles with HepG2 cells was studied after culturing cells in media containing the GM or L-conjugated GM (GL)

  15. Comparative analysis of 3D culture methods on human HepG2 cells.

    Science.gov (United States)

    Luckert, Claudia; Schulz, Christina; Lehmann, Nadja; Thomas, Maria; Hofmann, Ute; Hammad, Seddik; Hengstler, Jan G; Braeuning, Albert; Lampen, Alfonso; Hessel, Stefanie

    2017-01-01

    Human primary hepatocytes represent a gold standard in in vitro liver research. Due to their low availability and high costs alternative liver cell models with comparable morphological and biochemical characteristics have come into focus. The human hepatocarcinoma cell line HepG2 is often used as a liver model for toxicity studies. However, under two-dimensional (2D) cultivation conditions the expression of xenobiotic-metabolizing enzymes and typical liver markers such as albumin is very low. Cultivation for 21 days in a three-dimensional (3D) Matrigel culture system has been reported to strongly increase the metabolic competence of HepG2 cells. In our present study we further compared HepG2 cell cultivation in three different 3D systems: collagen, Matrigel and Alvetex culture. Cell morphology, albumin secretion, cytochrome P450 monooxygenase enzyme activities, as well as gene expression of xenobiotic-metabolizing and liver-specific enzymes were analyzed after 3, 7, 14, and 21 days of cultivation. Our results show that the previously reported increase of metabolic competence of HepG2 cells is not primarily the result of 3D culture but a consequence of the duration of cultivation. HepG2 cells grown for 21 days in 2D monolayer exhibit comparable biochemical characteristics, CYP activities and gene expression patterns as all 3D culture systems used in our study. However, CYP activities did not reach the level of HepaRG cells. In conclusion, the increase of metabolic competence of the hepatocarcinoma cell line HepG2 is not due to 3D cultivation but rather a result of prolonged cultivation time.

  16. Metabolism and cytotoxic effects of phosphatidylcholine hydroperoxide in human hepatoma HepG2 cells.

    Science.gov (United States)

    Suzuki, Yuuri; Nakagawa, Kiyotaka; Kato, Shunji; Tatewaki, Naoto; Mizuochi, Shunsuke; Ito, Junya; Eitsuka, Takahiro; Nishida, Hiroshi; Miyazawa, Teruo

    2015-03-20

    In this study, we investigated cellular uptake and metabolism of phosphatidylcholine hydroperoxide (PCOOH) in human hepatoma HepG2 cells by high performance liquid chromatography-tandem mass spectrometry, and then evaluated whether PCOOH or its metabolites cause pathophysiological effects such as cytotoxicity and apoptosis. Although we found that most PCOOH was reduced to PC hydroxide in HepG2 cells, the remaining PCOOH caused cytotoxic effects that may be mediated through an unusual apoptosis pathway. These results will enhance our fundamental understanding of how PCOOH, which is present in oxidized low density lipoproteins, is involved in the development of atherosclerosis. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. [Damage effect of Polygonum multiflorum fractions on human normal liver cells L02 and liver cancer cells HepG2].

    Science.gov (United States)

    Zhang, Ruichen; Zhang, Chao; Sun, Zhenxiao; Deng, Qiaohong

    2012-06-01

    To investigate the damage effect of different fractions from Polygonum multiflorum on normal human liver and liver cancer cells, in order to seek for fractions that can obviously kill cancer cells but have less impact on normal liver cells, and make a preliminary study on different mechanism of the two kinds of cells. P. multiflorum water-eluted fraction (RW), 50% ethanol-eluted fraction (R50) and 95% ethanol-eluted fraction (R95) were successively obtained from 70% ethanol extracts of P. multiflorum, after being eluted by water, 50% ethanol and 95% ethanol and then absorbed by AB-8 macroporous resin. Normal human liver L02 cells and liver cancer HepG2 cells were incubated with cell supernatants from different fractions and cells. MTT method and inverted microscope were adopted to observe the impact of L02 on growth of HepG2 cells, screening fractions with damage effect and detect their doses and time effect. Giemsa stain showed changes in cell nucleus after administration and flow cytometry analysis was used to detect cycle and apoptosis of L02 cells. MTT method and inverted microscope showed that R50 had significant growth inhibition effects on L02 and HepG2 cells. According to giemsa stain and flow cytometry analysis, R50 showed different effect on inducing the two cells: there are much more apoptotic HepG2 cells than apoptotic L02 cells in each time phase (the proportion of the apoptosis cells in HepG2 group were 83.62%, 60.52% and 74.49%, and ID2 31.02%, 20.57% and 25.32% after treated with R50 for 24, 48, 72 h. Both cells showed less than 5% of apoptotic cells in the negative control group in each time phase). However, there is no significant impact on cycle of both cells. R50 from P. multiflorum extracts had different damage effects on human liver L02 cells and liver cancer HepG2 cells, which was caused by different degree of induction on apoptosis of the two cells in nature.

  18. The cycloartane triterpenoid ADCX impairs autophagic degradation through Akt overactivation and promotes apoptotic cell death in multidrug-resistant HepG2/ADM cells.

    Science.gov (United States)

    Sun, Haiyan; Huang, Maohua; Yao, Nan; Hu, Jianyang; Li, Yingjie; Chen, Liping; Hu, Nan; Ye, Wencai; Chi-Shing Tai, William; Zhang, Dongmei; Chen, Sibao

    2017-12-15

    Multidrug resistance is the main obstacle in cancer chemotherapy. Emerging evidence demonstrates the important role of autophagy in cancer cell resistance to chemotherapy. Therefore, autophagy inhibition by natural compounds may be a promising strategy for overcoming drug resistance in liver cancer cells. Here, we found that ADCX, a natural cycloartane triterpenoid extracted from the traditional Chinese medicine (TCM) source Cimicifugae rhizoma (Shengma), impaired autophagic degradation by suppressing lysosomal cathepsin B (CTSB) expression in multidrug-resistant liver cancer HepG2/ADM cells, thereby leading to autophagic flux inhibition. Moreover, impairing autophagic flux promoted ADCX-induced apoptotic cell death in HepG2/ADM cells. Interestingly, Akt was overactivated by ADCX treatment, which downregulated CTSB and inhibited autophagic flux. Together, our results provide the first demonstration that an active TCM constituent can overcome multidrug resistance in liver cancer cells via Akt-mediated inhibition of autophagic degradation. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. The effect of solanine on the membrane potential of mitochondria in HepG2 cells and [Ca2+]i in the cells

    Science.gov (United States)

    Ji, YuBin; Gao, ShiYong; Ji, ChenFeng; Zou, Xiang

    2008-12-01

    To observe the effect of solanine on the membrane potential of mitochondria in HepG2 cells and [Ca2+]i in the cells, and to uncover the mechanism by which solanine induces apoptosis. HepG2 cells are double stained with and Fluo-3/AM, and both the change in membrane potential of mitochondria and that of [Ca2+]i in the cells are observed using LCSM. The results of double staining with TMRE and Fluo-3/AM show that solanine can lower membrane potential and increase the concentration of Ca2+ in the cells Solanine opens up the PT channels in the membrane by lowering the membrane potential, leading to Ca2+ being transported down its concentration gradient, which in turn leads to the rise of the concentration of Ca2+ in the cell, turning on the mechanism for apoptosis.

  20. Antioxidant and Proapoptotic Activities of Sclerocarya birrea [(A. Rich. Hochst.] Methanolic Root Extract on the Hepatocellular Carcinoma Cell Line HepG2

    Directory of Open Access Journals (Sweden)

    Maria Francesca Armentano

    2015-01-01

    Full Text Available The main goal of this study was to characterize the in vitro antioxidant activity and the apoptotic potential of S. birrea methanolic root extract (MRE. Among four tested extracts, obtained with different solvents, MRE showed the highest content of polyphenols, flavonoids, and tannins together with antioxidant activities tested with superoxide, nitric oxide, ABTS, and beta-carotene bleaching assays. Moreover, the cytotoxic effect of MRE was evaluated on the hepatocarcinoma cell line HepG2. In these cells, MRE treatment induced apoptosis and generated reactive oxygen species (ROS in dose-dependent manner. The cytotoxic effect promoted by MRE was prevented by pretreatment of HepG2 cells with N-acetyl-L-cysteine (NAC, suggesting that oxidative stress was pivotal in MRE-mediated cell death. Moreover, we showed that the MRE treatment induced the mitochondrial membrane depolarization and the cytochrome c release from mitochondria into the cytosol. It suggests that the apoptosis occurred in a mitochondrial-dependent pathway. Interestingly, MRE showed a sensibly lower cytotoxicity, associated with a low increase of ROS, in normal human dermal fibroblasts compared to HepG2 cells. It is suggested that the methanolic root extract of S. Birrea is able to selectively increase intracellular ROS levels in cancer cells, promoting cell death.

  1. The presence of oleate stabilized ZnO nanoparticles (NPs) and reduced the toxicity of aged NPs to Caco-2 and HepG2 cells.

    Science.gov (United States)

    Fang, Xin; Jiang, Leying; Gong, Yu; Li, Juan; Liu, Liangliang; Cao, Yi

    2017-12-25

    The presence of food components may alter the colloidal aspects and toxicity of nanoparticles (NPs). In this study, the toxicity of ZnO NPs to Caco-2 and HepG2 cells was assessed, with the emphasis on the interactions between ZnO NPs and oleate (OA). The presence of OA increased UV-Vis spectra and hydrodynamic sizes, decreased Zeta potential, and markedly reduced the release of Zn ions from the dissolution of ZnO NPs, which combined indicated that OA could coat ZnO NPs and stabilize ZnO NPs. Exposure to ZnO NPs significantly induced cytotoxicity to Caco-2 and HepG2 cells, associated with increased intracellular Zn ions but not superoxide. When OA was added to the freshly prepared ZnO NP suspensions, the cytotoxicity, intracellular Zn ions and superoxide induced by ZnO NPs were not significantly affected. However, when ZnO NPs were aged for 24 h with the presence of OA, the cytotoxicity of ZnO NPs to Caco-2 and HepG2 cells was significantly reduced, associated with a reduction of intracellular Zn ions. The results from this study suggested that the presence of OA could increase colloidal stability of ZnO NPs and consequently reduce the toxicity of ZnO NPs after aging associated with reduced accumulation of intracellular Zn ions. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Functional characterization of E2F3b in human HepG2 liver cancer cell line.

    Science.gov (United States)

    Lu, Yujia; Li, Wei

    2018-04-01

    E2F3 is a transcription factor that has been shown to be overexpressed in hepatocellular carcinoma (HCC). It is well-known that the E2F3 gene encodes two proteins E2F3a and E2F3b. Therefore, the functions of the two distinct isoforms need to be clarified separately. To characterize the function of E2F3b in HCC, the effects of ectopic expression of E2F3b on cell proliferation, cell cycle, apoptosis and gene expression were investigated. E2F3b promoted G1/S phase transition and markedly increased cell proliferation, but had minor effect on apoptosis. Microarray analyses identified 366 differentially expressed genes (171 upregulated and 195 downregulated) in E2F3b- overexpressing cells. Differential expression of 16 genes relevant to cell cycle and cell proliferation were further verified by real-time PCR. Six genes, including CDC2, CCNE1, ARF, MAP4K2, MUSK, and PAX2 were confirmed to be upregulated by more than twofold; one gene, CCNA2 was validated to be downregulated by more than twofold. We also confirmed that E2F3b increased the protein levels of both cyclin E and Arf but did not affect cyclin D1 protein. These results suggest that E2F3b functions as an important promoter for cell proliferation and plays important roles in transcriptional regulation in HepG2 liver cancer cells. © 2017 Wiley Periodicals, Inc.

  3. Possible regulation of LDL-receptor by naringenin in HepG2 ...

    African Journals Online (AJOL)

    Results: Time-course transient transfection of HepG2 cells with luciferase reporter-gene constructs incorporating the promoters of SREBP-1a,-1c, -2 and LDLr, revealed that in lipoprotein-deficient medium (LPDM), only SREBP-1a promoter activity was increased significantly after 4h exposure to 200μM naringenin ...

  4. Hyperglycemia and anthocyanin inhibit quercetin metabolism in HepG2 cells

    Science.gov (United States)

    A high glucose (Glu) milieu promotes generation of reactive oxygen species, which may not only cause cellular damage, but also modulate phase II enzymes that are responsible for the metabolism of flavonoids. Thus, we examined the effect of a high Glu milieu on quercetin (Q) metabolism in HepG2 cells...

  5. Cytotoxic effects of etephon and maleic hydrazide in Vero, Hep2, HepG2 cells.

    Science.gov (United States)

    Yurdakok, Begum; Baydan, Emine; Okur, Hamza; Gurcan, Ismayil Safa

    2014-10-01

    The toxicity of etephon and maleic hydrazide, used as plant growth regulators in agriculture, were reported as low in mammals in previous studies. However, in vitro cytotoxicity studies in mammalian cells are currently missing to understand their toxicity at molecular level. In the current study, the cytotoxicity of these compounds, were studied in Vero (African green monkey kidney epithelium), HepG2 (human hepatocellular carcinoma), Hep2 (human epidermoid cancer) cells by MTT ((3-(4,5-dimetiltiazol-2-il)-2,5-difeniltetrazolium bromure) and LDH (lactate dehydrogenase) assays. Maleic hydrazide had lower IC50 values for all cell lines compared to ethephon. Least cytotoxic effect treated by ethephon were observed in Vero, followed by HepG2 and Hep2. Similarly maleic hydrazide also showed least cytotoxicity on Vero cells, followed by Hep2 and HepG2 cells (p Vero cells, followed by HepG2 and Hep2 cells (p 0.868 (p cells to be supplemented by further studies.

  6. Selection of scFvs specific for the HepG2 cell line using ribosome ...

    Indian Academy of Sciences (India)

    The aim of this study was to construct a ribosome display library of single chain variable fragments (scFvs) associated with hepatocarcinoma and screen such a library for hepatocarcinoma-binding scFvs. mRNA was isolated from the spleens of mice immunized with hepatocellular carcinoma cell line HepG2. Heavy and k ...

  7. Anti-hepatocarcinoma effects of resveratrol nanoethosomes against human HepG2 cells

    Science.gov (United States)

    Meng, Xiang-Ping; Zhang, Zhen; Chen, Tong-sheng; Wang, Yi-fei; Wang, Zhi-ping

    2017-02-01

    Hepatocarcinoma, a malignant cancer, threaten human life badly. It is a current issue to seek the effective natural remedy from plant to treat cancer due to the resistance of the advanced hepatocarcinoma to chemotherapy. Resveratrol (Res) has been widely investigated with its strong anti-tumor activity. However, its low oral bioavailability restricts its wide application. In this study, we prepared resveratrol nanoethosomes (ResN) via ethanol injection method. The in vitro anti-hepatocarcinoma effects of ResN relative to efficacy of bulk Res were evaluated on proliferation and apoptosis of human HepG2 cells. ResN were spherical vesicles and its particle diameter, zeta potential were (115.8 +/- 1.3) nm and (-12.8 +/- 1.9) mV, respectively. ResN exhibited significant inhibitory effects against human HepG2 cells by MTT assay, and the IC50 value was 49.2 μg/ml (105.4 μg/ml of Res bulk solution). By flow cytometry assay, there was an increase in G2/M phase cells treated with ResN. The results demonstrated ResN could effectively block the G2/M phase of HepG2 cells, which can also enhance the inhibitory effect of Res against HepG2 cells.

  8. [6]-Gingerol inhibits de novo fatty acid synthesis and carnitine palmitoyltransferase-1 activity which triggers apoptosis in HepG2.

    Science.gov (United States)

    Impheng, Hathaichanok; Richert, Lysiane; Pekthong, Dumrongsak; Scholfield, C Norman; Pongcharoen, Sutatip; Pungpetchara, Ittipon; Srisawang, Piyarat

    2015-01-01

    The de novo fatty acid synthesis catalyzed by key lipogenic enzymes, including fatty acid synthase (FASN) has emerged as one of the novel targets of anti-cancer approaches. The present study explored the possible inhibitory efficacy of [6]-gingerol on de novo fatty acid synthesis associated with mitochondrial-dependent apoptotic induction in HepG2 cells. We observed a dissipation of mitochondrial membrane potential accompanied by a reduction of fatty acid levels. [6]-gingerol administration manifested inhibition of FASN expression, indicating FASN is a major target of [6]-gingerol inducing apoptosis in HepG2 cells. Indeed, we found that increased ROS generation could likely be a mediator of the anti-cancer effect of [6]-gingerol. A reduction of fatty acid levels and induction of apoptosis were restored by inhibition of acetyl-CoA carboxylase (ACC) activity, suggesting an accumulation of malonyl-CoA level could be the major cause of apoptotic induction of [6]-gingerol in HepG2 cells. The present study also showed that depletion of fatty acid following [6]-gingerol treatment caused an inhibitory effect on carnitine palmitoyltransferase-1 activity (CPT-1), whereas C75 augmented CPT-1 activity, indicating that [6]-gingerol exhibits the therapeutic benefit on suppression of fatty acid β-oxidation.

  9. Camel milk triggers apoptotic signaling pathways in human hepatoma HepG2 and breast cancer MCF7 cell lines through transcriptional mechanism.

    Science.gov (United States)

    Korashy, Hesham M; Maayah, Zaid H; Abd-Allah, Adel R; El-Kadi, Ayman O S; Alhaider, Abdulqader A

    2012-01-01

    Few published studies have reported the use of crude camel milk in the treatment of stomach infections, tuberculosis and cancer. Yet, little research was conducted on the effect of camel milk on the apoptosis and oxidative stress associated with human cancer. The present study investigated the effect and the underlying mechanisms of camel milk on the proliferation of human cancer cells using an in vitro model of human hepatoma (HepG2) and human breast (MCF7) cancer cells. Our results showed that camel milk, but not bovine milk, significantly inhibited HepG2 and MCF7 cells proliferation through the activation of caspase-3 mRNA and activity levels, and the induction of death receptors in both cell lines. In addition, Camel milk enhanced the expression of oxidative stress markers, heme oxygenase-1 and reactive oxygen species production in both cells. Mechanistically, the increase in caspase-3 mRNA levels by camel milk was completely blocked by the transcriptional inhibitor, actinomycin D; implying that camel milk increased de novo RNA synthesis. Furthermore, Inhibition of the mitogen activated protein kinases differentially modulated the camel milk-induced caspase-3 mRNA levels. Taken together, camel milk inhibited HepG2 and MCF7 cells survival and proliferation through the activation of both the extrinsic and intrinsic apoptotic pathways.

  10. Camel Milk Triggers Apoptotic Signaling Pathways in Human Hepatoma HepG2 and Breast Cancer MCF7 Cell Lines through Transcriptional Mechanism

    Directory of Open Access Journals (Sweden)

    Hesham M. Korashy

    2012-01-01

    Full Text Available Few published studies have reported the use of crude camel milk in the treatment of stomach infections, tuberculosis and cancer. Yet, little research was conducted on the effect of camel milk on the apoptosis and oxidative stress associated with human cancer. The present study investigated the effect and the underlying mechanisms of camel milk on the proliferation of human cancer cells using an in vitro model of human hepatoma (HepG2 and human breast (MCF7 cancer cells. Our results showed that camel milk, but not bovine milk, significantly inhibited HepG2 and MCF7 cells proliferation through the activation of caspase-3 mRNA and activity levels, and the induction of death receptors in both cell lines. In addition, Camel milk enhanced the expression of oxidative stress markers, heme oxygenase-1 and reactive oxygen species production in both cells. Mechanistically, the increase in caspase-3 mRNA levels by camel milk was completely blocked by the transcriptional inhibitor, actinomycin D; implying that camel milk increased de novo RNA synthesis. Furthermore, Inhibition of the mitogen activated protein kinases differentially modulated the camel milk-induced caspase-3 mRNA levels. Taken together, camel milk inhibited HepG2 and MCF7 cells survival and proliferation through the activation of both the extrinsic and intrinsic apoptotic pathways.

  11. A study of the mechanism of in vitro cytotoxicity of metal oxide nanoparticles using catfish primary hepatocytes and human HepG2 cells.

    Science.gov (United States)

    Wang, Yonggang; Aker, Winfred G; Hwang, Huey-min; Yedjou, Clement G; Yu, Hongtao; Tchounwou, Paul B

    2011-10-15

    Nanoparticles (NPs), including nanometal oxides, are being used in diverse applications such as medicine, clothing, cosmetics and food. In order to promote the safe development of nanotechnology, it is essential to assess the potential adverse health consequences associated with human exposure. The liver is a target site for NP toxicity, due to NP accumulation within it after ingestion, inhalation or absorption. The toxicity of nano-ZnO, TiO(2), CuO and Co(3)O(4) was investigated using a primary culture of channel catfish hepatocytes and human HepG2 cells as in vitro model systems for assessing the impact of metal oxide NPs on human and environmental health. Some mechanisms of nanotoxicity were determined by using phase contrast inverted microscopy, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays, reactive oxygen species (ROS) assays, and flow cytometric assays. Nano-CuO and ZnO showed significant toxicity in both HepG2 cells and catfish primary hepatocytes. The results demonstrate that HepG2 cells are more sensitive than catfish primary hepatocytes to the toxicity of metal oxide NPs. The overall ranking of the toxicity of metal oxides to the test cells is as follows: TiO(2)toxicity is due not only to ROS-induced cell death, but also to damages to cell and mitochondrial membranes. Copyright © 2011 Elsevier B.V. All rights reserved.

  12. Differential genomic effects of six different TiO2 nanomaterials on human liver HepG2 cells

    Science.gov (United States)

    Engineered nanoparticles are reported to cause liver toxicity in vivo. To better assess the mechanism of the in vivo liver toxicity, we used the human hepatocarcinoma cells (HepG2) as a model system. Human HepG2 cells were exposed to 6 TiO2 nanomaterials (with dry primary partic...

  13. Morin impedes Yap nuclear translocation and fosters apoptosis through suppression of Wnt/β-catenin and NF-κB signaling in Mst1 overexpressed HepG2 cells

    Energy Technology Data Exchange (ETDEWEB)

    Perumal, NaveenKumar [Department of Biochemistry, University of Madras, Guindy Campus, Chennai 600025, Tamil Nadu (India); Perumal, MadanKumar [Department of Biochemistry, University of Madras, Guindy Campus, Chennai 600025, Tamil Nadu (India); Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, Texas 75390 (United States); Kannan, Anbarasu [Department of Cellular and Molecular Biology, The University of Texas Health Science Center, Tyler, Texas (United States); Subramani, Kumar [Centre for Biotechnology, Anna University, Chennai 600025, Tamil Nadu (India); Halagowder, Devaraj [Department of Zoology, University of Madras, Guindy Campus, Chennai 600025, Tamil Nadu (India); Sivasithamparam, NiranjaliDevaraj, E-mail: profniranjali@gmail.com [Department of Biochemistry, University of Madras, Guindy Campus, Chennai 600025, Tamil Nadu (India)

    2017-06-15

    Recent clinical and experimental evidences strongly acclaim Yes-associated protein (Yap), a key oncogenic driver in liver carcinogenesis, as a therapeutic target. Of the known multiple schemes to inhibit Yap activity, activation of Mammalian Sterile 20-like Kinase 1 (Mst1), an upstream regulator of Yap, appears to be a promising one. In this study, we hypothesize that morin, a bioflavonoid, mediates its anti-cancer effect through the activation of Mst1/hippo signaling in liver cancer cells. To test this hypothesis, both full length Mst1 (F-Mst1) and kinase active N-terminal Mst1 (N-Mst1)-overexpressed HepG2 cells were used. Exposure of F-Mst1 overexpressed HepG2 cells to morin activated Mst1 by caspase-3 cleavage and thereby inhibited Yap nuclear translocation and fostered apoptosis. Morin suppressed NF-κB p65 and Wnt/β-catenin signaling through Mst1 activation via cleavage and phosphorylation, leading to cell death. Annexin-V/PI staining further confirmed the induction of apoptosis in morin treated F-Mst1 overexpressed cells. The present study shows that morin targets cell survival molecules such as NF-κB p65 and β-catenin through activation of hippo signaling. Therefore, morin could be considered as a potential anti-cancer agent against liver cancer. - Highlights: • Morin induced cytotoxicity in cultured HepG2 cells. • Morin activated hippo pathway via Mst1 activation in transfected HepG2 cells. • Morin suppressed Wnt/β-catenin signaling and induced G0/G1 cell cycle arrest. • Morin inhibited NF-κB signaling through Mst1 activation in transfected HepG2 cells. • Morin potentiates apoptosis through Mst1-JNK-caspase mediated mechanism in HepG2 cells.

  14. Upregulation of hemoglobin expression by oxidative stress in hepatocytes and its implication in nonalcoholic steatohepatitis.

    Science.gov (United States)

    Liu, Wensheng; Baker, Susan S; Baker, Robert D; Nowak, Norma J; Zhu, Lixin

    2011-01-01

    Recent studies revealed that hemoglobin is expressed in some non-erythrocytes and it suppresses oxidative stress when overexpressed. Oxidative stress plays a critical role in the pathogenesis of non-alcoholic steatohepatitis (NASH). This study was designed to investigate whether hemoglobin is expressed in hepatocytes and how it is related to oxidative stress in NASH patients. Analysis of microarray gene expression data revealed a significant increase in the expression of hemoglobin alpha (HBA1) and beta (HBB) in liver biopsies from NASH patients. Increased hemoglobin expression in NASH was validated by quantitative real time PCR. However, the expression of hematopoietic transcriptional factors and erythrocyte specific marker genes were not increased, indicating that increased hemoglobin expression in NASH was not from erythropoiesis, but could result from increased expression in hepatocytes. Immunofluorescence staining demonstrated positive HBA1 and HBB expression in the hepatocytes of NASH livers. Hemoglobin expression was also observed in human hepatocellular carcinoma HepG2 cell line. Furthermore, treatment with hydrogen peroxide, a known oxidative stress inducer, increased HBA1 and HBB expression in HepG2 and HEK293 cells. Importantly, hemoglobin overexpression suppressed oxidative stress in HepG2 cells. We concluded that hemoglobin is expressed by hepatocytes and oxidative stress upregulates its expression. Suppression of oxidative stress by hemoglobin could be a mechanism to protect hepatocytes from oxidative damage in NASH.

  15. Upregulation of hemoglobin expression by oxidative stress in hepatocytes and its implication in nonalcoholic steatohepatitis.

    Directory of Open Access Journals (Sweden)

    Wensheng Liu

    Full Text Available Recent studies revealed that hemoglobin is expressed in some non-erythrocytes and it suppresses oxidative stress when overexpressed. Oxidative stress plays a critical role in the pathogenesis of non-alcoholic steatohepatitis (NASH. This study was designed to investigate whether hemoglobin is expressed in hepatocytes and how it is related to oxidative stress in NASH patients. Analysis of microarray gene expression data revealed a significant increase in the expression of hemoglobin alpha (HBA1 and beta (HBB in liver biopsies from NASH patients. Increased hemoglobin expression in NASH was validated by quantitative real time PCR. However, the expression of hematopoietic transcriptional factors and erythrocyte specific marker genes were not increased, indicating that increased hemoglobin expression in NASH was not from erythropoiesis, but could result from increased expression in hepatocytes. Immunofluorescence staining demonstrated positive HBA1 and HBB expression in the hepatocytes of NASH livers. Hemoglobin expression was also observed in human hepatocellular carcinoma HepG2 cell line. Furthermore, treatment with hydrogen peroxide, a known oxidative stress inducer, increased HBA1 and HBB expression in HepG2 and HEK293 cells. Importantly, hemoglobin overexpression suppressed oxidative stress in HepG2 cells. We concluded that hemoglobin is expressed by hepatocytes and oxidative stress upregulates its expression. Suppression of oxidative stress by hemoglobin could be a mechanism to protect hepatocytes from oxidative damage in NASH.

  16. PLGA-based gene delivering nanoparticle enhance suppression effect of miRNA in HePG2 cells

    Directory of Open Access Journals (Sweden)

    Liang Gao

    2011-01-01

    Full Text Available Abstract The biggest challenge in the field of gene therapy is how to effectively deliver target genes to special cells. This study aimed to develop a new type of poly(D,L-lactide-co-glycolide (PLGA-based nanoparticles for gene delivery, which are capable of overcoming the disadvantages of polyethylenimine (PEI- or cationic liposome-based gene carrier, such as the cytotoxicity induced by excess positive charge, as well as the aggregation on the cell surface. The PLGA-based nanoparticles presented in this study were synthesized by emulsion evaporation method and characterized by transmission electron microscopy, dynamic light scattering, and energy dispersive spectroscopy. The size of PLGA/PEI nanoparticles in phosphate-buffered saline (PBS was about 60 nm at the optimal charge ratio. Without observable aggregation, the nanoparticles showed a better monodispersity. The PLGA-based nanoparticles were used as vector carrier for miRNA transfection in HepG2 cells. It exhibited a higher transfection efficiency and lower cytotoxicity in HepG2 cells compared to the PEI/DNA complex. The N/P ratio (ratio of the polymer nitrogen to the DNA phosphate 6 of the PLGA/PEI/DNA nanocomplex displays the best property among various N/P proportions, yielding similar transfection efficiency when compared to Lipofectamine/DNA lipoplexes. Moreover, nanocomplex shows better serum compatibility than commercial liposome. PLGA nanocomplexes obviously accumulate in tumor cells after transfection, which indicate that the complexes contribute to cellular uptake of pDNA and pronouncedly enhance the treatment effect of miR-26a by inducing cell cycle arrest. Therefore, these results demonstrate that PLGA/PEI nanoparticles are promising non-viral vectors for gene delivery.

  17. PLGA-based gene delivering nanoparticle enhance suppression effect of miRNA in HePG2 cells

    Science.gov (United States)

    Feng Liang, Gao; Zhu, Yan Liang; Sun, Bo; Hu, Fei Hu; Tian, Tian; Li, Shu Chun; Xiao, Zhong Dang

    2011-07-01

    The biggest challenge in the field of gene therapy is how to effectively deliver target genes to special cells. This study aimed to develop a new type of poly( D, L-lactide-co-glycolide) (PLGA)-based nanoparticles for gene delivery, which are capable of overcoming the disadvantages of polyethylenimine (PEI)- or cationic liposome-based gene carrier, such as the cytotoxicity induced by excess positive charge, as well as the aggregation on the cell surface. The PLGA-based nanoparticles presented in this study were synthesized by emulsion evaporation method and characterized by transmission electron microscopy, dynamic light scattering, and energy dispersive spectroscopy. The size of PLGA/PEI nanoparticles in phosphate-buffered saline (PBS) was about 60 nm at the optimal charge ratio. Without observable aggregation, the nanoparticles showed a better monodispersity. The PLGA-based nanoparticles were used as vector carrier for miRNA transfection in HepG2 cells. It exhibited a higher transfection efficiency and lower cytotoxicity in HepG2 cells compared to the PEI/DNA complex. The N/P ratio (ratio of the polymer nitrogen to the DNA phosphate) 6 of the PLGA/PEI/DNA nanocomplex displays the best property among various N/P proportions, yielding similar transfection efficiency when compared to Lipofectamine/DNA lipoplexes. Moreover, nanocomplex shows better serum compatibility than commercial liposome. PLGA nanocomplexes obviously accumulate in tumor cells after transfection, which indicate that the complexes contribute to cellular uptake of pDNA and pronouncedly enhance the treatment effect of miR-26a by inducing cell cycle arrest. Therefore, these results demonstrate that PLGA/PEI nanoparticles are promising non-viral vectors for gene delivery.

  18. Comparison of gene expression profiles of HepG2 cells exposed to Crambescins C1 and A1

    Directory of Open Access Journals (Sweden)

    María R. Sánchez

    2014-06-01

    Full Text Available Crambescins are guanidine alkaloids firstly isolated in the early 90s from the encrusting Mediterranean sponge Crambe crambe (Schmidt, 1862 (Bondu et al., 2012, Laville et al., 2009, Berlinck et al., 1990. C. crambe derivatives are divided in two families named crambescins and crambescidins (Gerlinck et al., 1992. Although data on the bioactivity of these compounds is scarce, crambescidins have recognized cytotoxic, antifungal, antioxidant, antimicrobial and antiviral activities (Buscema and Van de Vyver, 1985, Jares-Erijman., 1998, Olszewski et al., 2004, Lazaro et al., 2006, Suna et al., 2007, AOKI et al., 2004. Recently we have carefully evaluated the cytotoxic activity of C816 over several human tumor cell types and characterized some of the cellular mechanisms responsible of the anti-proliferative effect of this compound on human liver-derived tumor cells (Rubiolo et al., 2013. Taking this into account, and to better understand the mechanism of action of crambescins and their potential as therapeutic agents, we made a comparative gene expression profiling of HepG2 cells after crambescin C1 (C1 and crambescin A1 (CA1 exposures. Results have shown that C1 induces genes involved in sterol and glucose metabolisms and metabolism involving growth factors. It also down regulates genes mainly involved in cell cycle control, DNA replication, recombination and repair, and drug metabolism. Flow cytometry assays revealed that C1 produces a G0/G1 arrest in HepG2 cell cycle progression. CA1 also down-regulates genes involved in cell cycle regulation, DNA recombination and pathways related to tumor cells proliferation with lower potency when compared to C1.

  19. Simulated Microgravity Induces SOST/Sclerostin Upregulation in Osteocytes

    Science.gov (United States)

    Spatz, Jordan; Sibonga, Jean; Wu, Honglu; Barry, Kevin; Bouxsein, Mary; Pajevic, Paola Divieti

    2010-01-01

    Osteocytes are theorized to be the mechanosensors and transducers of mechanical forces in bone, yet the biological mechanism of this action remains elusive. Recent evidence suggests that SOST/Sclerostin is an important regulator of mechano-transduction. To investigate the molecular mechanisms of SOST/Sclerostin regulation under in-vitro and ex-vivo unloading we used the NASA Rotating Wall Vessel(RWV) Bioreactor. For in-vitro experiments, MLOY-4 osteocytic cells were seeded at a concentration of 250,000 cells onto 3D collagen scaffold (BD). Scaffolds (4 per condition) were either rotated in a vertical 50ml NASA/bioreactor vessel at 18 rpm (unloaded), cultured in a horizontal 50 ml NASA bioreactor vessel at 18 rpm (control for the sheared environment of vertical rotating vessel), or cultured in a static T-75 cm dish (static condition ) for 7days. For ex-vivo experiments, calvaria bones were harvested from 12-week old C57/Bl6 mice and sequentially digested with type I/II collagenase to remove periosteal osteoblasts. Calvaria halves (10 per condition) were then exposed to the same set of culture conditions described above. Simulated unloading, as achieved in the NASA RWV, resulted in enlarged, round osteocytes, as assessed by H&E staining, that was reminiscent of prior reports of unloading causing loss of osteocyte morphology and dendritic network connectivity. Semiquantitative realtime qPCR and immunohistochemistry from both in-vitro and ex-vivo RWV experiments demonstrated a four-fold up-regulation of SOST/Sclerostin. Furthermore, mRNA of the transcriptional SOST enhancer Mef2C was upregulated 1.4 fold in ex-vivo calvaria subjected to unloading conditions of the NASA RWV, suggesting that Mef2C might be an important regulator of mechano-sensation. These findings are consistent with results from seven day hindlimb unloading experiments, C57/B6 females, conducted in our laboratory and validate the use of the NASA RWV as a tool to study osteocyte mechanotransduction

  20. Long Non-coding RNAs Expression Profile in HepG2 Cells Reveals the Potential Role of Long Non-coding RNAs in the Cholesterol Metabolism

    Directory of Open Access Journals (Sweden)

    Gang Liu

    2015-01-01

    Full Text Available Background: Green tea has been shown to improve cholesterol metabolism in animal studies, but the molecular mechanisms underlying this function have not been fully understood. Long non-coding RNAs (lncRNAs have recently emerged as a major class of regulatory molecules involved in a broad range of biological processes and complex diseases. Our aim was to identify important lncRNAs that might play an important role in contributing to the benefits of epigallocatechin-3-gallate (EGCG on cholesterol metabolism. Methods: Microarrays was used to reveal the lncRNA and mRNA profiles in green tea polyphenol(--epigallocatechin gallate in cultured human liver (HepG2 hepatocytes treated with EGCG and bioinformatic analyses of the predicted target genes were performed to identify lncRNA-mRNA targeting relationships. RNA interference was used to investigate the role of lncRNAs in cholesterol metabolism. Results: The expression levels of 15 genes related to cholesterol metabolism and 285 lncRNAs were changed by EGCG treatment. Bioinformatic analysis found five matched lncRNA-mRNA pairs for five differentially expressed lncRNAs and four differentially expressed mRNA. In particular, the lncRNA AT102202 and its potential targets mRNA-3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR were identified. Using a real-time polymerase chain reaction technique, we confirmed that EGCG down-regulated mRNA expression level of the HMGCR and up-regulated expression of AT102202. After AT102202 knockdown in HepG2, we observed that the level of HMGCR expression was significantly increased relative to the scrambled small interfering RNA control (P < 0.05. Conclusions: Our results indicated that EGCG improved cholesterol metabolism and meanwhile changed the lncRNAs expression profile in HepG2 cells. LncRNAs may play an important role in the cholesterol metabolism.

  1. Long Non-coding RNAs Expression Profile in HepG2 Cells Reveals the Potential Role of Long Non-coding RNAs in the Cholesterol Metabolism

    Science.gov (United States)

    Liu, Gang; Zheng, Xinxin; Xu, Yanlu; Lu, Jie; Chen, Jingzhou; Huang, Xiaohong

    2015-01-01

    Background: Green tea has been shown to improve cholesterol metabolism in animal studies, but the molecular mechanisms underlying this function have not been fully understood. Long non-coding RNAs (lncRNAs) have recently emerged as a major class of regulatory molecules involved in a broad range of biological processes and complex diseases. Our aim was to identify important lncRNAs that might play an important role in contributing to the benefits of epigallocatechin-3-gallate (EGCG) on cholesterol metabolism. Methods: Microarrays was used to reveal the lncRNA and mRNA profiles in green tea polyphenol(-)-epigallocatechin gallate in cultured human liver (HepG2) hepatocytes treated with EGCG and bioinformatic analyses of the predicted target genes were performed to identify lncRNA-mRNA targeting relationships. RNA interference was used to investigate the role of lncRNAs in cholesterol metabolism. Results: The expression levels of 15 genes related to cholesterol metabolism and 285 lncRNAs were changed by EGCG treatment. Bioinformatic analysis found five matched lncRNA-mRNA pairs for five differentially expressed lncRNAs and four differentially expressed mRNA. In particular, the lncRNA AT102202 and its potential targets mRNA-3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR) were identified. Using a real-time polymerase chain reaction technique, we confirmed that EGCG down-regulated mRNA expression level of the HMGCR and up-regulated expression of AT102202. After AT102202 knockdown in HepG2, we observed that the level of HMGCR expression was significantly increased relative to the scrambled small interfering RNA control (P < 0.05). Conclusions: Our results indicated that EGCG improved cholesterol metabolism and meanwhile changed the lncRNAs expression profile in HepG2 cells. LncRNAs may play an important role in the cholesterol metabolism. PMID:25563320

  2. Interleukin-6 upregulates paraoxonase 1 gene expression via an AKT/NF-κB-dependent pathway

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Chi-Chih [Department of Research, Taichung Veterans General Hospital, Taichung, Taiwan (China); Hsueh, Chi-Mei [Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan (China); Chen, Chiu-Yuan [Graduate Institute of Natural Healing Sciences, Nanhua University, Chiayi, Taiwan (China); Chen, Tzu-Hsiu, E-mail: hsiu@mail.chna.edu.tw [Department of Health and Nutrition, Chia Nan University of Pharmacy and Science, Tainan, Taiwan (China); Hsu, Shih-Lan, E-mail: h2326@vghtc.gov.tw [Department of Research, Taichung Veterans General Hospital, Taichung, Taiwan (China); Department of Applied Chemistry, National Chi Nan University, Puli, Nantou, Taiwan (China)

    2013-07-19

    Highlights: •IL-6 could induce PON1 gene expression. •IL-6 increased NF-κB protein expression and NF-κB-p50 and -p65 subunits nuclear translocation. •IL-6-induced PON1 up-regulation was through an AKT/NF-κB pathway. -- Abstract: The aim of this study is to investigate the relationship between paraoxonase 1 (PON1) and atherosclerosis-related inflammation. In this study, human hepatoma HepG2 cell line was used as a hepatocyte model to examine the effects of the pro-inflammatory cytokines on PON1 expression. The results showed that IL-6, but not TNF-α and IL-1β, significantly increased both the function and protein level of PON1; data from real-time RT-PCR analysis revealed that the IL-6-induced PON1 expression occurred at the transcriptional level. Increase of IκB kinase activity and IκB phosphorylation, and reduction of IκB protein level were also observed in IL-6-treated HepG2 cells compared with untreated culture. This event was accompanied by increase of NF-κB-p50 and -p65 nuclear translocation. Moreover, treatment with IL-6 augmented the DNA binding activity of NF-κB. Furthermore, pharmacological inhibition of NF-κB activation by PDTC and BAY 11-7082, markedly suppressed the IL-6-mediated PON1 expression. In addition, IL-6 increased the levels of phosphorylated protein kinase B (PKB, AKT). An AKT inhibitor LY294002 effectively suppressed IKK/IκB/NF-κB signaling and PON1 gene expression induced by IL-6. Our findings demonstrate that IL-6 upregulates PON1 gene expression through an AKT/NF-κB signaling axis in human hepatocyte-derived HepG2 cell line.

  3. Biosynthesis of hematite nanoparticles and its cytotoxic effect on HepG2 cancer cells.

    Science.gov (United States)

    Rajendran, Kumar; Karunagaran, Vithiya; Mahanty, Biswanath; Sen, Shampa

    2015-03-01

    Iron oxide nanoparticles were gaining significant importance in a variety of applications due to its paramagnetic properties and biocompatibility. Various chemical methods were employed for hematite nanoparticle synthesis which require special equipment or a complex production process. In this study, protein capped crystalline hexagonal hematite (α-Fe2O3) nanoparticles were synthesized by green approach using culture supernatant of a newly isolated bacterium, Bacillus cereus SVK1 at ambient conditions. The synthesized nanoparticles were characterized by electron microscopy, X-ray diffraction, UV-visible spectroscopy and Fourier transform infrared spectroscopic analysis. Nanoparticles were evaluated for its possible anticancer activity against HepG2 liver cancer cells by MTT assay. Hematite nanoparticles with an average diameter of 30.2 nm, exhibited a significant cytotoxicity toward HepG2 cells in a concentration-dependent manner (CTC50=704 ng/ml). Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Palmitic acid suppresses apolipoprotein M gene expression via the pathway of PPAR{sub β/δ} in HepG2 cells

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Guanghua; Shi, Yuanping; Zhang, Jun; Mu, Qinfeng; Qin, Li; Zheng, Lu; Feng, Yuehua [Comprehensive Laboratory, The Third Affiliated Hospital of Soochow University, Changzhou 213003 (China); Berggren-Söderlund, Maria; Nilsson-Ehle, Peter [Division of Clinical Chemistry and Pharmacology, Department of Laboratory Medicine, Lund University, S-221 85 Lund (Sweden); Zhang, Xiaoying, E-mail: zhangxy6689996@163.com [Department of Cardiothoracic Surgery, The Third Affiliated Hospital of Soochow University, Changzhou 213003 (China); Xu, Ning, E-mail: ning.xu@med.lu.se [Division of Clinical Chemistry and Pharmacology, Department of Laboratory Medicine, Lund University, S-221 85 Lund (Sweden)

    2014-02-28

    Highlights: • Palmitic acid significantly inhibited APOM gene expression in HepG2 cells. • Palmitic acid could obviously increase PPARB/D mRNA levels in HepG2 cells. • PPAR{sub β/δ} antagonist, GSK3787, had no effect on APOM expression. • GSK3787 could reverse the palmitic acid-induced down-regulation of APOM expression. • Palmitic acid induced suppression of APOM expression is mediated via the PPAR{sub β/δ} pathway. - Abstract: It has been demonstrated that apolipoprotein M (APOM) is a vasculoprotective constituent of high density lipoprotein (HDL), which could be related to the anti-atherosclerotic property of HDL. Investigation of regulation of APOM expression is of important for further exploring its pathophysiological function in vivo. Our previous studies indicated that expression of APOM could be regulated by platelet activating factor (PAF), transforming growth factors (TGF), insulin-like growth factor (IGF), leptin, hyperglycemia and etc., in vivo and/or in vitro. In the present study, we demonstrated that palmitic acid could significantly inhibit APOM gene expression in HepG2 cells. Further study indicated neither PI-3 kinase (PI3K) inhibitor LY294002 nor protein kinase C (PKC) inhibitor GFX could abolish palmitic acid induced down-regulation of APOM expression. In contrast, the peroxisome proliferator-activated receptor beta/delta (PPAR{sub β/δ}) antagonist GSK3787 could totally reverse the palmitic acid-induced down-regulation of APOM expression, which clearly demonstrates that down-regulation of APOM expression induced by palmitic acid is mediated via the PPAR{sub β/δ} pathway.

  5. Taurine reduces the secretion of apolipoprotein B100 and lipids in HepG2 cells

    OpenAIRE

    Nagao Koji; Hu Ying; Han Seo-Young; Yanagita Teruyoshi; Kitajima Hideaki; Murakami Shigeru

    2008-01-01

    Abstract Background Higher concentrations of serum lipids and apolipoprotein B100 (apoB) are major individual risk factors of atherosclerosis and coronary heart disease. Therefore ameliorative effects of food components against the diseases are being paid attention in the affluent countries. The present study was undertaken to investigate the effect of taurine on apoB secretion and lipid metabolism in human liver model HepG2 cells. Results The results demonstrated that an addition of taurine ...

  6. Selection of scFvs specific for the HepG2 cell line using ribosome ...

    Indian Academy of Sciences (India)

    Madhsudhan

    Such a library would prove useful for direct intact cell panning using ribosome display technology. The selected scFv had a potential value for hepatocarcinoma treatment. [Zhou L, Mao W-P, Fen J, Liu H-Y, Wei C-J, Li W-X and Zhou F-Y 2009 Selection of scFvs specific for the HepG2 cell line using ribosome display;.

  7. Trombinol, a bioactive fraction of Psidium guajava, stimulates thrombopoietin expression in HepG2 cells

    OpenAIRE

    Berlian, Guntur; Tandrasasmita, Olivia Mayasari; Tjandrawinata, Raymond Rubianto

    2017-01-01

    Objective: To study the regulation of trombinol on thrombopoietin, an essential regulator of thrombocyte production. Methods: Effect of trombinol on thrombopoietin regulation was evaluated at the mRNA and protein levels in human hepatoma HepG2 cells. The mRNA expressions were revealed by PCR and real-time PCR, while the protein expressions were analyzed using western blotting and human ELISA kit. Statistical differences between the test were determined by student's t-test with P 

  8. New strategy of photodynamic treatment of TiO2 nanofibers combined with celastrol for HepG2 proliferation in vitro

    Science.gov (United States)

    Li, Jingyuan; Wang, Xuemei; Jiang, Hui; Lu, Xiaohua; Zhu, Yudan; Chen, Baoan

    2011-08-01

    As one of the best biocompatible semiconductor nanomaterials, TiO2 nanofibers can act as a good photosensitizer material and show potential application in the field of drug carriers and photodynamic therapy to cure diseases. Celastrol, one of the active components extracted from T. wilfordii Hook F., was widely used in traditional Chinese medicine for many diseases. In this study, the cytotoxicity of celastrol for HepG2 cancer cells was firstly explored. The results showed that celastrol could inhibit cancer cell proliferation in a time-dependent and dose-dependent manner, inducing apoptosis and cell cycle arrest at G2/M phase in HepG2 cells. After the TiO2 nanofibers were introduced into the system of celastrol, the cooperation effect showed that the nanocomposites between TiO2 nanofibers and celastrol could enhance the cytotoxicity of celastrol for HepG2 cells and cut down the drug consumption so as to reduce the side-effect of the related drug. Associated with the photodynamic effect, it is evident that TiO2 nanofibers could readily facilitate the potential application of the active compounds from natural products like celastrol. Turning to the advantages of nanotechnology, the combination of nanomaterials with the related monomer active compounds of promising Chinese medicine could play an important role to explore the relevant mechanism of the drug cellular interaction and promote the potential application of TiO2 nanofibers in the clinical treatment.As one of the best biocompatible semiconductor nanomaterials, TiO2 nanofibers can act as a good photosensitizer material and show potential application in the field of drug carriers and photodynamic therapy to cure diseases. Celastrol, one of the active components extracted from T. wilfordii Hook F., was widely used in traditional Chinese medicine for many diseases. In this study, the cytotoxicity of celastrol for HepG2 cancer cells was firstly explored. The results showed that celastrol could inhibit cancer cell

  9. Proteome analysis of the effects of sorafenib on human hepatocellular carcinoma cell line HepG2.

    Science.gov (United States)

    Suo, Aili; Zhang, Mingxin; Yao, Yu; Zhang, Lingmin; Huang, Chen; Nan, Kejun; Zhang, Wanggang

    2012-09-01

    Sorafenib is a multi-target oral anticancer drug used as first-line treatment for patients with advanced human hepatocellular carcinoma (HCC). But the exact mechanism of sorafenib involved in HCC treatment is not clear yet. In this study, a comparative proteomic approach was performed to identify novel sorafenib-related proteins in HCC. Proteomes of HepG2 cells treated with sorafenib and the control (without sorafenib) were obtained by two-dimensional differential gel electrophoresis. Comprehensive analysis of proteins was focused on total protein spots to filtrate the different protein spots between the two groups. The differentially expressed proteins were identified by peptide mass fingerprinting with high-performance liquid chromatography-tandem mass spectrometry. Then, Western blot and immunohistochemistry were used to verify the expression of some candidate proteins. Results indicated that 19 protein spots were differentially expressed with significant changes, including 6 up-regulated proteins and 13 down-regulated proteins. It was confirmed by Western blot that expressions of Annexin A1 and cyclophilin A were down-regulated in sorafenib-treated HCC cell lines. Immunohistochemical study revealed their oncogenic role in HCC tissues. These observations might be novel findings leading to bring new insights into the exact mechanism of sorafenib and identify possible therapeutic targets.

  10. Tripterygium regelii decreases the biosynthesis of triacylglycerol and cholesterol in HepG2 cells.

    Science.gov (United States)

    Kang, Myung-Ji; Kwon, Eun-Bin; Yuk, Heung Joo; Ryu, Hyung Won; Kim, Soo-Yeon; Lee, Mi-Kyeong; Moon, Dong-Oh; Lee, Su Ui; Oh, Sei-Ryang; Lee, Hyun-Sun; Kim, Mun-Ock

    2017-12-01

    In the course of screening to find a plant material decreasing the activity of triacylglycerol and cholesterol, we identified Tripterygium regelii (TR). The methanol extract of TR leaves (TR-LM) was shown to reduce the intracellular lipid contents consisting of triacylglycerol (TG) and cholesterol in HepG2 cells. TR-LM also downregulated the mRNA and protein expression of the lipogenic genes such as SREBP-1 and its target enzymes. Consequently, TR-LM reduced the TG biosynthesis in HepG2 cells. In addition, TR-LM decreased SREBP2 and its target enzyme HMG-CoA reductase, which is involved in cholesterol synthesis. In this study, we evaluated that TR-LM attenuated cellular lipid contents through the suppression of de novo TG and cholesterol biosynthesis in HepG2 cells. All these taken together, TR-LM could be beneficial in regulating lipid metabolism and useful preventing the hyperlipidemia and its complications, in that liver is a crucial tissue for the secretion of serum lipids.

  11. In HepG2 cells, coexisting carnitine deficiency masks important indicators of marginal biotin deficiency.

    Science.gov (United States)

    Bogusiewicz, Anna; Boysen, Gunnar; Mock, Donald M

    2015-01-01

    A large number of birth defects are related to nutrient deficiencies; concern that biotin deficiency is teratogenic in humans is reasonable. Surprisingly, studies indicate that increased urinary 3-hydroxyisovalerylcarnitine (3HIAc), a previously validated marker of biotin deficiency, is not a valid biomarker in pregnancy. In this study we hypothesized that coexisting carnitine deficiency can prevent the increase in 3HIAc due to biotin deficiency. We used a 2-factor nutrient depletion design to induce isolated and combined biotin and carnitine deficiency in HepG2 cells and then repleted cells with carnitine. To elucidate the metabolic pathogenesis, we quantitated intracellular and extracellular free carnitine, acylcarnitines, and acylcarnitine ratios using liquid chromatography-tandem mass spectrometry. Relative to biotin-sufficient, carnitine-sufficient cells, intracellular acetylcarnitine increased by 90%, propionylcarnitine more than doubled, and 3HIAc increased by >10-fold in biotin-deficient, carnitine-sufficient (BDCS) cells, consistent with a defensive mechanism in which biotin-deficient cells transesterify the acyl-coenzyme A (acyl-CoA) substrates of the biotin-dependent carboxylases to the related acylcarnitines. Likewise, in BDCS cells, the ratio of acetylcarnitine to malonylcarnitine and the ratio of propionylcarnitine to methylmalonylcarnitine both more than tripled, and the ratio of 3HIAc to 3-methylglutarylcarnitine (MGc) increased by >10-fold. In biotin-deficient, carnitine-deficient (BDCD) cells, the 3 substrate-derived acylcarnitines changed little, but the substrate:product ratios were masked to a lesser extent. Moreover, carnitine repletion unmasked biotin deficiency in BDCD cells as shown by increases in acetylcarnitine, propionylcarnitine, and 3HIAc (each increased by >50-fold). Likewise, ratios of acetylcarnitine:malonylcarnitine, propionylcarnitine:methylmalonylcarnitine, and 3HIAc:MGc all increased by >8-fold. Our findings provide strong

  12. Gene expression profiling and network analysis reveals lipid and steroid metabolism to be the most favored by TNFalpha in HepG2 cells.

    Directory of Open Access Journals (Sweden)

    Amit K Pandey

    Full Text Available BACKGROUND: The proinflammatory cytokine, TNFalpha, is a crucial mediator of the pathogenesis of several diseases, more so in cases involving the liver wherein it is critical in maintaining liver homeostasis since it is a major determiner of hepatocyte life and death. Gene expression profiling serves as an appropriate strategy to unravel the underlying signatures to envisage such varied responses and considering this, gene transcription profiling was examined in control and TNFalpha treated HepG2 cells. METHODS AND FINDINGS: Microarray experiments between control and TNFalpha treated HepG2 cells indicated that TNFalpha could significantly alter the expression profiling of 140 genes; among those up-regulated, several GO (Gene Ontology terms related to lipid and fat metabolism were significantly (p<0.01 overrepresented indicating a global preference of fat metabolism within the hepatocyte and those within the down-regulated dataset included genes involved in several aspects of the immune response like immunoglobulin receptor activity and IgE binding thereby indicating a compromise in the immune defense mechanism(s. Conserved transcription factor binding sites were identified in identically clustered genes within a common GO term and SREBP-1 and FOXJ2 depicted increased occupation of their respective binding elements in the presence of TNFalpha. The interacting network of "lipid metabolism, small molecule biochemistry" was derived to be significantly overrepresented that correlated well with the top canonical pathway of "biosynthesis of steroids". CONCLUSIONS: TNFalpha alters the transcriptome profiling within HepG2 cells with an interesting catalog of genes being affected and those involved in lipid and steroid metabolism to be the most favored. This study represents a composite analysis of the effects of TNFalpha in HepG2 cells that encompasses the altered transcriptome profiling, the functional analysis of the up- and down- regulated genes and

  13. The Interactions between ZnO Nanoparticles (NPs and α-Linolenic Acid (LNA Complexed to BSA Did Not Influence the Toxicity of ZnO NPs on HepG2 Cells

    Directory of Open Access Journals (Sweden)

    Yiwei Zhou

    2017-04-01

    Full Text Available Background: Nanoparticles (NPs entering the biological environment could interact with biomolecules, but little is known about the interaction between unsaturated fatty acids (UFA and NPs. Methods: This study used α-linolenic acid (LNA complexed to bovine serum albumin (BSA for UFA and HepG2 cells for hepatocytes. The interactions between BSA or LNA and ZnO NPs were studied. Results: The presence of BSA or LNA affected the hydrodynamic size, zeta potential, UV-Vis, fluorescence, and synchronous fluorescence spectra of ZnO NPs, which indicated an interaction between BSA or LNA and NPs. Exposure to ZnO NPs with the presence of BSA significantly induced the damage to mitochondria and lysosomes in HepG2 cells, associated with an increase of intracellular Zn ions, but not intracellular superoxide. Paradoxically, the release of inflammatory cytokine interleukin-6 (IL-6 was decreased, which indicated the anti-inflammatory effects of ZnO NPs when BSA was present. The presence of LNA did not significantly affect all of these endpoints in HepG2 cells exposed to ZnO NPs and BSA. Conclusions: the results from the present study indicated that BSA-complexed LNA might modestly interact with ZnO NPs, but did not significantly affect ZnO NPs and BSA-induced biological effects in HepG2 cells.

  14. Nicotine-induced upregulation of native neuronal nicotinic receptors is caused by multiple mechanisms

    Science.gov (United States)

    Govind, Anitha P.; Walsh, Heather; Green, William N.

    2012-01-01

    Nicotine causes changes in brain nicotinic acetylcholine receptors (nAChRs) during smoking that initiate addiction. Nicotine-induced upregulation is the long-lasting increase in nAChR radio-ligand binding sites in brain resulting from exposure. The mechanisms causing upregulation are not established. Many different mechanisms have been reported with the assumption that there is a single, underlying cause. Using live cortical neurons, we examined for the first time how exposure and withdrawal of nicotine shape the kinetics of native α4β2-containing nAChR upregulation in real time. Upregulation kinetics demonstrate that at least two different mechanisms underlie this phenomenon. First, a transient upregulation occurs that rapidly reverses, faster than nAChR degradation, and corresponds to nAChR conformational changes as assayed by conformational-dependent, subunit-specific antibodies. Second, a long-lasting process occurs correlating with increases in nAChR numbers caused by decreased proteasomal subunit degradation. Previous radio-ligand binding measurements to brain tissue have measured the second process and largely missed the first. We conclude that nicotine-induced upregulation is composed of multiple processes occurring at different rates with different underlying causes. PMID:22323734

  15. Dimethyl Fumarate Induces Glutathione Recycling by Upregulation of Glutathione Reductase.

    Science.gov (United States)

    Hoffmann, Christina; Dietrich, Michael; Herrmann, Ann-Kathrin; Schacht, Teresa; Albrecht, Philipp; Methner, Axel

    2017-01-01

    Neuronal degeneration in multiple sclerosis has been linked to oxidative stress. Dimethyl fumarate (DMF) is an effective oral therapeutic option shown to reduce disease activity and progression in patients with relapsing-remitting multiple sclerosis. DMF activates the transcription factor nuclear factor erythroid 2-related factor 2 (NRF2) leading to increased synthesis of the major cellular antioxidant glutathione (GSH) and prominent neuroprotection in vitro . We previously demonstrated that DMF is capable of raising GSH levels even when glutathione synthesis is inhibited, suggesting enhanced GSH recycling. Here, we found that DMF indeed induces glutathione reductase (GSR), a homodimeric flavoprotein that catalyzes GSSG reduction to GSH by using NADPH as a reducing cofactor. Knockdown of GSR using a pool of E. coli RNase III-digested siRNAs or pharmacological inhibition of GSR, however, also induced the antioxidant response rendering it impossible to verify the suspected attenuation of DMF-mediated neuroprotection. However, in cystine-free medium, where GSH synthesis is abolished, pharmacological inhibition of GSR drastically reduced the effect of DMF on glutathione recycling. We conclude that DMF increases glutathione recycling through induction of glutathione reductase.

  16. Dimethyl Fumarate Induces Glutathione Recycling by Upregulation of Glutathione Reductase

    Directory of Open Access Journals (Sweden)

    Christina Hoffmann

    2017-01-01

    Full Text Available Neuronal degeneration in multiple sclerosis has been linked to oxidative stress. Dimethyl fumarate (DMF is an effective oral therapeutic option shown to reduce disease activity and progression in patients with relapsing-remitting multiple sclerosis. DMF activates the transcription factor nuclear factor erythroid 2-related factor 2 (NRF2 leading to increased synthesis of the major cellular antioxidant glutathione (GSH and prominent neuroprotection in vitro. We previously demonstrated that DMF is capable of raising GSH levels even when glutathione synthesis is inhibited, suggesting enhanced GSH recycling. Here, we found that DMF indeed induces glutathione reductase (GSR, a homodimeric flavoprotein that catalyzes GSSG reduction to GSH by using NADPH as a reducing cofactor. Knockdown of GSR using a pool of E. coli RNase III-digested siRNAs or pharmacological inhibition of GSR, however, also induced the antioxidant response rendering it impossible to verify the suspected attenuation of DMF-mediated neuroprotection. However, in cystine-free medium, where GSH synthesis is abolished, pharmacological inhibition of GSR drastically reduced the effect of DMF on glutathione recycling. We conclude that DMF increases glutathione recycling through induction of glutathione reductase.

  17. SphK1 inhibitor SKI II inhibits the proliferation of human hepatoma HepG2 cells via the Wnt5A/β-catenin signaling pathway.

    Science.gov (United States)

    Liu, Hong; Zhang, Cai-Xia; Ma, Yan; He, Hong-Wei; Wang, Jia-Ping; Shao, Rong-Guang

    2016-04-15

    Sphingosine 1-phosphate (S1P) promotes cell growth, proliferation and survival. Sphingosine kinase 1 (SphK1), which converts sphingosine to S1P, is a key promoter in cancer. We previously found that the SphK1 inhibitor II (SKI II), suppresses the cell growth and induces apoptosis in human hepatoma HepG2 cells. However, the precise regulatory mechanism and signaling pathway on SKI II inhibiting tumor growth remains unknown. The expressions of β-catenin and related molecules of Wnt/β-catenin signal were detected by western blot in HepG2 cells. And the mRNA expression of β-catenin was detected by RT-PCR. The Wnt5A gene was silenced by siRNA. The colony formation was determined by staining with crystal violet. And the cell growth was examined by SRB assay and BrdU assay. We found that SKI II decreased the expression of β-catenin and the downstream molecules of β-catenin signal pathway and promotes the β-catenin degradation. In addition, SKI II induced the expression of Wnt5A, and then triggered β-catenin degradation. Furthermore, silencing Wnt5A decreased the anti-tumor effects of SKI II through recovering the expressions of β-catenin and downstream molecules of β-catenin signal pathway. SKI II-induced downregulation of HepG2 cell proliferation was associated with Wnt signaling pathway through Wnt5A-mediated β-catenin degradation. Our study revealed that a novel signal pathway was involved in SKI II-inhibited cell proliferation in human hepatoma cells. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Differential genomic effects on signaling pathways by two different CeO2 nanoparticles in HepG2 cells

    Data.gov (United States)

    U.S. Environmental Protection Agency — Differential genomic effects on signaling pathways by two different CeO2 nanoparticles in HepG2 cells. This dataset is associated with the following publication:...

  19. Microfluidic wet spinning of chitosan-alginate microfibers and encapsulation of HepG2 cells in fibers

    OpenAIRE

    Lee, Bo Ram; Lee, Kwang Ho; Kang, Edward; Kim, Dong-Sik; Lee, Sang-Hoon

    2011-01-01

    The successful encapsulation of human hepatocellular carcinoma (HepG2) cells would greatly assist a broad range of applications in tissue engineering. Due to the harsh conditions during standard chitosan fiber fabrication processes, encapsulation of HepG2 cells in chitosan fibers has been challenging. Here, we describe the successful wet-spinning of chitosan-alginate fibers using a coaxial flow microfluidic chip. We determined the optimal mixing conditions for generating chitosan-alginate fib...

  20. A combination of transcriptomics and metabolomics uncovers enhanced bile acid biosynthesis in HepG2 cells expressing CCAAT/enhancer-binding protein β (C/EBPβ), hepatocyte nuclear factor 4α (HNF4α), and constitutive androstane receptor (CAR).

    Science.gov (United States)

    Blazquez, Marina; Carretero, Aitor; Ellis, James K; Athersuch, Toby J; Cavill, Rachel; Ebbels, Timothy M D; Keun, Hector C; Castell, José V; Lahoz, Agustín; Bort, Roque

    2013-06-07

    The development of hepatoma-based in vitro models to study hepatocyte physiology is an invaluable tool for both industry and academia. Here, we develop an in vitro model based on the HepG2 cell line that produces chenodeoxycholic acid, the main bile acid in humans, in amounts comparable to human hepatocytes. A combination of adenoviral transfections for CCAAT/enhancer-binding protein β (C/EBPβ), hepatocyte nuclear factor 4α (HNF4α), and constitutive androstane receptor (CAR) decreased intracellular glutamate, succinate, leucine, and valine levels in HepG2 cells, suggestive of a switch to catabolism to increase lipogenic acetyl CoA and increased anaplerosis to replenish the tricarboxylic acid cycle. Transcripts of key genes involved in bile acid synthesis were significantly induced by approximately 160-fold. Consistently, chenodeoxycholic acid production rate was increased by more than 20-fold. Comparison between mRNA and bile acid levels suggest that 12-alpha hydroxylation of 7-alpha-hydroxy-4-cholesten-3-one is the limiting step in cholic acid synthesis in HepG2 cells. These data reveal that introduction of three hepatocyte-related transcription factors enhance anabolic reactions in HepG2 cells and provide a suitable model to study bile acid biosynthesis under pathophysiological conditions.

  1. Protective effect of polysaccharide from maca (Lepidium meyenii) on Hep-G2 cells and alcoholic liver oxidative injury in mice.

    Science.gov (United States)

    Zhang, Lijun; Zhao, Qingsheng; Wang, Liwei; Zhao, Mingxia; Zhao, Bing

    2017-06-01

    To study the characterization and hepatoprotective activity of polysaccharide from maca (Lepidium meyenii), the main polysaccharide from maca (MP-1) was obtained by DEAE-52 cellulose column. The average molecular weight of MP-1 was 1067.3kDa and the polysaccharide purity was 91.63%. In order to assess the antioxidant activities of MP-1, four kinds of methods were used, including scavenging hydroxyl radical, DPPH, superoxide anion radical, and FRAP, and the results indicated high antioxidant activities. Furthermore, hepatoprotective activity of MP-1 was studied both in vitro and vivo. In vitro, the alcohol induced Hep-G2 cells model was established to evaluate the protective effect of MP-1, which demonstrated MP-1 can alleviate alcohol damage in Hep-G2 cells. In vivo, the Institute of Cancer Researcch (ICR) mice were used to evaluate hepatoprotecive effects of MP-1 on alcoholic liver disease (ALD). Supplement with MP-1 supressed the triglyceride level both in serum and in hepatic tissue. In addition, MP-1 ameliorated serous transaminases increase induced by alcohol, including aspartate transaminase, alanine aminotransferase, and γ-glutamyl transpeptidase. Moreover, MP-1 also dramatically increased the superoxide dismutase, glutathione peroxidase, and glutathione s-transferase levels in alcoholic mice. Meantime, histopathologic results MP-1 lighten inflammation induced by alcohol. These results indicate that MP-1 possesses hepatoprotective activity against hepatic injury induced by alcohol. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Microfluidic wet spinning of chitosan-alginate microfibers and encapsulation of HepG2 cells in fibers.

    Science.gov (United States)

    Lee, Bo Ram; Lee, Kwang Ho; Kang, Edward; Kim, Dong-Sik; Lee, Sang-Hoon

    2011-06-01

    The successful encapsulation of human hepatocellular carcinoma (HepG2) cells would greatly assist a broad range of applications in tissue engineering. Due to the harsh conditions during standard chitosan fiber fabrication processes, encapsulation of HepG2 cells in chitosan fibers has been challenging. Here, we describe the successful wet-spinning of chitosan-alginate fibers using a coaxial flow microfluidic chip. We determined the optimal mixing conditions for generating chitosan-alginate fibers, including a 1:5 ratio of 2% (w∕w) water-soluble chitosan (WSC) solution to 2% (w∕w) alginate solution. Ratio including higher than 2% (w∕w) WSC solution increased aggregation throughout the mixture. By suspending cells in the WSC-alginate solution, we successfully fabricated HepG2 cell-laden fibers. The encapsulated HepG2 cells in the chitosan-alginate fibers were more viable than cells encapsulated in pure alginate fibers, suggesting that cross-linked chitosan provides a better environment for HepG2 cells than alginate alone. In addition, we found that the adhesion of HepG2 cells on the chitosan-alginate fiber is much better than that on the alginate fibers.

  3. Upregulation of Interferon-inducible and damage response pathways in chronic graft-versus-host disease

    Science.gov (United States)

    Hakim, Frances T.; Memon, Sarfraz; Jin, Ping; Imanguli, Matin M.; Wang, Huan; Rehman, Najibah; Yan, Xiao-Yi; Rose, Jeremy; Mays, Jacqueline W.; Dhamala, Susan; Kapoor, Veena; Telford, William; Dickinson, John; Davis, Sean; Halverson, David; Naik, Haley B.; Baird, Kristin; Fowler, Daniel; Stroncek, David; Cowen, Edward W.; Pavletic, Steven Z.; Gress, Ronald E.

    2016-01-01

    Although Chronic Graft-versus-Host Disease (CGVHD) is the primary non-relapse complication of allogeneic transplantation, understanding of its pathogenesis is limited. To identify the main operant pathways across the spectrum of CGVHD, we analyzed gene expression in circulating monocytes, chosen as in situ systemic reporter cells. Microarrays identified two interrelated pathways: (1) Interferon-inducible genes and (2) innate receptors for cellular damage. Corroborating these with multiplex RNA quantitation, we found that multiple IFN-inducible genes (affecting lymphocyte trafficking, differentiation and antigen presentation) were concurrently upregulated in CGVHD monocytes compared to normal and nonCGVHD controls. IFN-inducible chemokines were elevated in both lichenoid and sclerotic CGHVD plasma and linked to CXCR3+ lymphocyte trafficking. Furthermore, the IFN-inducible genes CXCL10 and TNFSF13B (BAFF) levels were correlated at both the gene and plasma levels, implicating IFN-induction as a factor in elevated BAFF levels in CGVHD. In the second pathway, DAMP/PAMP receptor genes capable of inducing Type I IFN were upregulated. Type I IFN-inducible MxA was expressed in proportion to CGVHD activity in skin, mucosa and glands, and expression of TLR and RIG-1 receptor genes correlated with upregulation of Type I IFN-inducible genes in monocytes. Finally, in serial analyses following transplant, IFN-inducible and damage-response genes were upregulated in monocytes at CGVHD onset and declined upon therapy and resolution in both lichenoid and sclerotic CGVHD patients. This interlocking analysis of IFN-inducible genes, plasma analytes and tissue immunohistochemistry strongly supports a unifying hypothesis of induction of IFN by innate response to cellular damage as a mechanism for initiation and persistence of CGVHD. PMID:27694491

  4. Low density lipoprotein induces upregulation of vasoconstrictive endothelin type B receptor expression

    DEFF Research Database (Denmark)

    Xu, Cang-Bao; Zheng, Jian-Pu; Zhang, Wei

    2014-01-01

    Vasoconstrictive endothelin type B (ET(B)) receptors promote vasospasm and ischemic cerebro- and cardiovascular diseases. The present study was designed to examine if low density lipoprotein (LDL) induces upregulation of vasoconstrictive ET(B) receptor expression and if extracellular signal...

  5. Lipid synthesis and secretion in HepG2 cells is not affected by ACTH

    Directory of Open Access Journals (Sweden)

    Nilsson-Ehle Peter

    2010-05-01

    Full Text Available Abstract Apolipoprotein B (apoB containing lipoproteins, i.e. VLDL, LDL and Lp(a, are consequently lowered by ACTH treatment in humans. This is also seen as reduced plasma apoB by 20-30% and total cholesterol by 30-40%, mostly accounted for by a decrease in LDL-cholesterol. Studies in hepatic cell line (HepG2 cells showed that apoB mRNA expression is reduced in response to ACTH incubation and is followed by a reduced apoB secretion, which may hypothesize that ACTH lowering apoB containing lipoproteins in humans may be mediated by the inhibition of hepatic apoB synthesis. This was recently confirmed in vivo in a human postprandial study, where ACTH reduced transient apoB48 elevation from the small intestine, however, the exogenic lipid turnover seemed unimpaired. In the present study we investigated if lipid synthesis and/or secretion in HepG2 cells were also affected by pharmacological levels of ACTH to accompany the reduced apoB output. HepG2 cells were incubated with radiolabelled precursors ([14C]acetate and [3H]glycerol either before or during ACTH stimuli. Cellular and secreted lipids were extracted with chloroform:methanol and separated by the thin layer chromatography (TLC, and [14C]labelled cholesterol and cholesteryl ester and [3H]labelled triglycerides and phospholipids were quantitated by the liquid scintillation counting. It demonstrated that ACTH administration did not result in any significant change in neither synthesis nor secretion of the studied lipids, this regardless of presence or absence of oleic acid, which is known to stabilize apoB and enhance apoB production. The present study suggests that ACTH lowers plasma lipids in humans mainly mediated by the inhibition of apoB synthesis and did not via the reduced lipid synthesis.

  6. Intact stable isotope labeled plasma proteins from the SILAC-labeled HepG2 secretome.

    Science.gov (United States)

    Mangrum, John B; Martin, Erika J; Brophy, Donald F; Hawkridge, Adam M

    2015-09-01

    The plasma proteome remains an attractive biospecimen for MS-based biomarker discovery studies. The success of these efforts relies on the continued development of quantitative MS-based proteomics approaches. Herein we report the use of the SILAC-labeled HepG2 secretome as a source for stable isotope labeled plasma proteins for quantitative LC-MS/MS measurements. The HepG2 liver cancer cell line secretes the major plasma proteins including serum albumin, apolipoproteins, protease inhibitors, coagulation factors, and transporters that represent some of the most abundant proteins in plasma. The SILAC-labeled HepG2 secretome was collected, spiked into human plasma (1:1 total protein), and then processed for LC-MS/MS analysis. A total of 62 and 56 plasma proteins were quantified (heavy:light (H/L) peptide pairs) from undepleted and depleted (serum albumin and IgG), respectively, with log2 H/L = ± 6. Major plasma proteins quantified included albumin, apolipoproteins (e.g., APOA1, APOA2, APOA4, APOB, APOC3, APOE, APOH, and APOM), protease inhibitors (e.g., A2M and SERPINs), coagulation factors (e.g., Factor V, Factor X, fibrinogen), and transport proteins (e.g., TTR). The average log2 H/L values for shared plasma proteins in both undepleted and depleted plasma samples were 0.43 and 0.44, respectively. This work further expands the SILAC strategy into MS-based biomarker discovery of clinical biospecimens. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Proposing a Caco-2/HepG2 cell model for in vitro iron absorption studies.

    Science.gov (United States)

    Scheers, Nathalie M; Almgren, Annette B; Sandberg, Ann-Sofie

    2014-07-01

    The Caco-2 cell line is well established as an in vitro model for iron absorption. However, the model does not reflect the regulation of iron absorption by hepcidin produced in the liver. We aimed to develop the Caco-2 model by introducing human liver cells (HepG2) to Caco-2 cells. The Caco-2 and HepG2 epithelia were separated by a liquid compartment, which allowed for epithelial interaction. Ferritin levels in cocultured Caco-2 controls were 21.7±10.3 ng/mg protein compared to 7.7±5.8 ng/mg protein in monocultured Caco-2 cells. The iron transport across Caco-2 layers was increased when liver cells were present (8.1%±1.5% compared to 3.5%±2.5% at 120 μM Fe). Caco-2 cells were exposed to 0, 80 and 120 μM Fe and responded with increased hepcidin production at 120 μM Fe (3.6±0.3 ng/ml compared to 2.7±0.3 ng/ml). The expression of iron exporter ferroportin in Caco-2 cells was decreased at the hepcidin concentration of 3.6 ng/ml and undetectable at external addition of hepcidin (10 ng/ml). The apical transporter DMT1 was also undetectable at 10 ng/ml but was unchanged at the lower concentrations. In addition, we observed that sourdough bread, in comparison to heat-treated bread, increased the bioavailability of iron despite similar iron content (53% increase in ferritin formation, 97% increase in hepcidin release). This effect was not observed in monocultured Caco-2 cells. The Caco-2/HepG2 model provides an alternative approach to in vitro iron absorption studies in which the hepatic regulation of iron transport must be considered. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  8. Cellular trafficking of thymosin beta-4 in HEPG2 cells following serum starvation.

    Directory of Open Access Journals (Sweden)

    Giuseppina Pichiri

    Full Text Available Thymosin beta-4 (Tβ4 is an ubiquitous multi-functional regenerative peptide, related to many critical biological processes, with a dynamic and flexible conformation which may influence its functions and its subcellular distribution. For these reasons, the intracellular localization and trafficking of Tβ4 is still not completely defined and is still under investigation in in vivo as well as in vitro studies. In the current study we used HepG2 cells, a human hepatoma cell line; cells growing in normal conditions with fetal bovine serum expressed high levels of Tβ4, restricted to the cytoplasm until 72 h. At 84 h, a diffuse Tβ4 cytoplasmic immunostaining shifted to a focal perinuclear and nuclear reactivity. In the absence of serum, nuclear reactivity was localized in small granules, evenly dispersed throughout the entire nuclear envelop, and was observed as earlier as at 48 h. Cytoplasmic immunostaining for Tβ4 in HepG2 cells under starvation appeared significantly lower at 48 h and decreased progressively at 72 and at 84 h. At these time points, the decrease in cytoplasmic staining was associated with a progressive increase in nuclear reactivity, suggesting a possible translocation of the peptide from the cytoplasm to the nuclear membrane. The normal immunocytochemical pattern was restored when culture cells submitted to starvation for 84 h received a new complete medium for 48 h. Mass spectrometry analysis, performed on the nuclear and cytosolic fractions of HepG2 growing with and without serum, showed that Tβ4 was detectable only in the cytosolic and not in the intranuclear fraction. These data suggest that Tβ4 is able to translocate from different cytoplasmic domains to the nuclear membrane and back, based on different stress conditions within the cell. The punctuate pattern of nuclear Tβ4 immunostaining associated with Tβ4 absence in the nucleoplasm suggest that this peptide might be localized in the nuclear pores, where it could regulate the pore permeability.

  9. The selective target of capsaicin on FASN expression and de novo fatty acid synthesis mediated through ROS generation triggers apoptosis in HepG2 cells.

    Directory of Open Access Journals (Sweden)

    Hathaichanok Impheng

    Full Text Available The inhibition of the mammalian de novo synthesis of long-chain saturated fatty acids (LCFAs by blocking the fatty acid synthase (FASN enzyme activity in tumor cells that overexpress FASN can promote apoptosis, without apparent cytotoxic to non-tumor cells. The present study aimed to focus on the potent inhibitory effect of capsaicin on the fatty acid synthesis pathway inducing apoptosis of capsaicin in HepG2 cells. The use of capsaicin as a source for a new FASN inhibitor will provide new insight into its possible application as a selective anti-cancer therapy. The present findings showed that capsaicin promoted apoptosis as well as cell cycle arrest in the G0/G1 phase. The onset of apoptosis was correlated with a dissipation of mitochondrial membrane potential (ΔΨm. Apoptotic induction by capsaicin was mediated by inhibition of FASN protein expression which was accompanied by decreasing its activity on the de novo fatty acid synthesis. The expression of FASN was higher in HepG2 cells than in normal hepatocytes that were resistant to undergoing apoptosis following capsaicin administration. Moreover, the inhibitory effect of capsaicin on FASN expression and activity was found to be mediated by an increase of intracellular reactive oxygen species (ROS generation. Treatment of HepG2 cells with capsaicin failed to alter ACC and ACLY protein expression, suggesting ACC and ACLY might not be the specific targets of capsaicin to induce apoptosis. An accumulation of malonyl-CoA level following FASN inhibition represented a major cause of mitochondrial-dependent apoptotic induction instead of deprivation of fatty acid per se. Here, we also obtained similar results with C75 that exhibited apoptosis induction by reducing the levels of fatty acid without any change in the abundance of FASN expression along with increasing ROS production. Collectively, our results provide novel evidence that capsaicin exhibits a potent anti-cancer property by targeting

  10. Synergy analysis reveals association between insulin signaling and desmoplakin expression in palmitate treated HepG2 cells.

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    Xuewei Wang

    Full Text Available The regulation of complex cellular activities in palmitate treated HepG2 cells, and the ensuing cytotoxic phenotype, involves cooperative interactions between genes. While previous approaches have largely focused on identifying individual target genes, elucidating interacting genes has thus far remained elusive. We applied the concept of information synergy to reconstruct a "gene-cooperativity" network for palmititate-induced cytotoxicity in liver cells. Our approach integrated gene expression data with metabolic profiles to select a subset of genes for network reconstruction. Subsequent analysis of the network revealed insulin signaling as the most significantly enriched pathway, and desmoplakin (DSP as its top neighbor. We determined that palmitate significantly reduces DSP expression, and treatment with insulin restores the lost expression of DSP. Insulin resistance is a common pathological feature of fatty liver and related ailments, whereas loss of DSP has been noted in liver carcinoma. Reduced DSP expression can lead to loss of cell-cell adhesion via desmosomes, and disrupt the keratin intermediate filament network. Our findings suggest that DSP expression may be perturbed by palmitate and, along with insulin resistance, may play a role in palmitate induced cytotoxicity, and serve as potential targets for further studies on non-alcoholic fatty liver disease (NAFLD.

  11. The supercritical CO₂ extract from the skin of Bufo bufo gargarizans Cantor blocks hepatitis B virus antigen secretion in HepG2.2.15 cells.

    Science.gov (United States)

    Cui, Xiaoyan; Inagaki, Yoshinori; Wang, Dongliang; Gao, Jianjun; Qi, Fanghua; Gao, Bo; Kokudo, Norihiro; Fang, Dingzhi; Tang, Wei

    2014-02-01

    The skin of Bufo bufo gargarizans Cantor has long been used for the treatment of hepatitis B in China and supercritical carbon dioxide extraction (SC-CO₂) is widely used in extracting active ingredients from natural products. The aim of present study was to assess the anti-hepatitis B virus (HBV) effect of the supercritical CO₂ extract from the skin of Bufo bufo gargarizans Cantor (SCE-BC). Cytotoxicity of SCE-BC was analyzed using an MTT [3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide] assay in HepG2.2.15 cells. The hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg), and hepatitis B core-related antigen (HBcrAg) concentrations in cell culture medium were determined by chemiluminescent enzyme immunoassay. HBV mRNA in cells was determined using real-time polymerase chain reaction. SCE-BC concentrations below 10(-2) μg/mL had no significant toxicity to HepG2.2.15 cells. SCE-BC at 10(-4) μg/mL effectively inhibited the secretion of HBeAg by 23.36% on day 6. It was more potent than the positive control lamivudine (100 μg/mL) in terms of the inhibition of HBeAg and HBcrAg secretion on day 6. Consistent with the HBV antigen reduction, HBV mRNA expression was markedly inhibited in comparison to the control when HepG2.2.15 cells were treated with SCE-BC. Moreover, SCE-BC had greater inhibitory activity with respect to HBeAg than to HBsAg. Since HBeAg promotes immune tolerance and persistent infection during HBV infection, the present results suggest that immune tolerance induced by HBeAg might be overcome by SCE-BC. Therefore, SCE-BC warrants further investigation.

  12. Hepatotoxicity assessment of the azo dyes disperse orange 1 (DO1), disperse red 1 (DR1) and disperse red 13 (DR13) in HEPG2 cells.

    Science.gov (United States)

    Ferraz, Elisa R A; Li, Zhaohui; Boubriak, Olga; de Oliveira, Danielle P

    2012-01-01

    During the dyeing process in baths approximately 10 to 15% of the dyes used are lost and reach industrial effluents, thus polluting the environment. Studies showed that some classes of dyes, mainly azo dyes and their by-products, exert adverse effects on humans and local biota, since the wastewater treatment systems and water treatment plants were found to be ineffective in removing the color and reducing toxicity of some dyes. In the present study, the toxicity of the azo dyes disperse orange 1 (DO1), disperse red 1 (DR1), and disperse red 13 (DR13) was evaluated in HepG2 cells grown in monolayers or in three dimensional (3D) culture. Hepatotoxicity of the dyes was measured using 3-(4,5-dimethylthiazol-2yl)2,5-diphenyltetrazolium (MTT) and cell counting kit 8 (CCK-8) assays after 24, 48, and 72 h of incubation of cells with 3 different concentrations of the azo dyes. The dye DO1 only reduced the mitochondrial activity in HepG2 cells grown in a monolayer after 72 h incubation, while the dye DR1 showed this deleterious effect in both monolayer and 3D culture. In contrast, dye DR13 decreased the mitochondrial activity after 24, 48, and 72 h of exposure in both monolayer and 3D culture. With respect to dehydrogenase activity, only the dye DR13 diminished the activity of this enzyme after 72 h of exposure in both monolayer and 3D culture. Our results clearly demonstrated that exposure to the studied dyes induced cytotoxicity in HepG2 cells.

  13. Predictivity of dog co-culture model, primary human hepatocytes and HepG2 cells for the detection of hepatotoxic drugs in humans

    Energy Technology Data Exchange (ETDEWEB)

    Atienzar, Franck A., E-mail: franck.atienzar@ucb.com [UCB Pharma SA, Non-Clinical Development, Chemin du Foriest, 1420 Braine-l' Alleud (Belgium); Novik, Eric I. [H mu rel Corporation, 675 U.S. Highway 1, North Brunswick, NJ 08902 (United States); Gerets, Helga H. [UCB Pharma SA, Non-Clinical Development, Chemin du Foriest, 1420 Braine-l' Alleud (Belgium); Parekh, Amit [H mu rel Corporation, 675 U.S. Highway 1, North Brunswick, NJ 08902 (United States); Delatour, Claude; Cardenas, Alvaro [UCB Pharma SA, Non-Clinical Development, Chemin du Foriest, 1420 Braine-l' Alleud (Belgium); MacDonald, James [Chrysalis Pharma Consulting, LLC, 385 Route 24, Suite 1G, Chester, NJ 07930 (United States); Yarmush, Martin L. [Department of Biomedical Engineering, Rutgers University, Piscataway, NJ 08854 (United States); Dhalluin, Stéphane [UCB Pharma SA, Non-Clinical Development, Chemin du Foriest, 1420 Braine-l' Alleud (Belgium)

    2014-02-15

    Drug Induced Liver Injury (DILI) is a major cause of attrition during early and late stage drug development. Consequently, there is a need to develop better in vitro primary hepatocyte models from different species for predicting hepatotoxicity in both animals and humans early in drug development. Dog is often chosen as the non-rodent species for toxicology studies. Unfortunately, dog in vitro models allowing long term cultures are not available. The objective of the present manuscript is to describe the development of a co-culture dog model for predicting hepatotoxic drugs in humans and to compare the predictivity of the canine model along with primary human hepatocytes and HepG2 cells. After rigorous optimization, the dog co-culture model displayed metabolic capacities that were maintained up to 2 weeks which indicates that such model could be also used for long term metabolism studies. Most of the human hepatotoxic drugs were detected with a sensitivity of approximately 80% (n = 40) for the three cellular models. Nevertheless, the specificity was low approximately 40% for the HepG2 cells and hepatocytes compared to 72.7% for the canine model (n = 11). Furthermore, the dog co-culture model showed a higher superiority for the classification of 5 pairs of close structural analogs with different DILI concerns in comparison to both human cellular models. Finally, the reproducibility of the canine system was also satisfactory with a coefficient of correlation of 75.2% (n = 14). Overall, the present manuscript indicates that the dog co-culture model may represent a relevant tool to perform chronic hepatotoxicity and metabolism studies. - Highlights: • Importance of species differences in drug development. • Relevance of dog co-culture model for metabolism and toxicology studies. • Hepatotoxicity: higher predictivity of dog co-culture vs HepG2 and human hepatocytes.

  14. Crambescin C1 Exerts a Cytoprotective Effect on HepG2 Cells through Metallothionein Induction

    Science.gov (United States)

    Roel, María; Rubiolo, Juan A.; Ternon, Eva; Thomas, Olivier P.; Vieytes, Mercedes R.; Botana, Luis M.

    2015-01-01

    The Mediterranean marine sponge Crambe crambe is the source of two families of guanidine alkaloids known as crambescins and crambescidins. Some of the biological effects of crambescidins have been previously reported while crambescins have undergone little study. Taking this into account, we performed comparative transcriptome analysis to examine the effect of crambescin-C1 (CC1) on human tumor hepatocarcinoma cells HepG2 followed by validation experiments to confirm its predicted biological activities. We report herein that, while crambescin-A1 has a minor effect on these cells, CC1 protects them against oxidative injury by means of metallothionein induction even at low concentrations. Additionally, at high doses, CC1 arrests the HepG2 cell cycle in G0/G1 and thus inhibits tumor cell proliferation. The findings presented here provide the first detailed approach regarding the different effects of crambescins on tumor cells and provide a basis for future studies on other possible cellular mechanisms related to these bioactivities. PMID:26225985

  15. Taurine reduces the secretion of apolipoprotein B100 and lipids in HepG2 cells

    Directory of Open Access Journals (Sweden)

    Nagao Koji

    2008-10-01

    Full Text Available Abstract Background Higher concentrations of serum lipids and apolipoprotein B100 (apoB are major individual risk factors of atherosclerosis and coronary heart disease. Therefore ameliorative effects of food components against the diseases are being paid attention in the affluent countries. The present study was undertaken to investigate the effect of taurine on apoB secretion and lipid metabolism in human liver model HepG2 cells. Results The results demonstrated that an addition of taurine to the culture media reduces triacylglycerol (TG-mass in the cells and the medium. Similarly, cellular cholesterol-mass was decreased. Taurine inhibited the incorporation of [14C] oleate into cellular and medium TG, suggesting the inhibition of TG synthesis. In addition, taurine reduced the synthesis of cellular cholesterol ester and its secretion, suggesting the inhibition of acyl-coenzyme A:cholesterol acyltransferase activity. Furthermore, taurine reduced the secretion of apoB, which is a major protein component of very low-density lipoprotein. Conclusion This is a first report to demonstrate that taurine inhibits the secretion of apoB from HepG2 cells.

  16. A proteomic analysis of mushroom polysaccharide-treated HepG2 cells.

    Science.gov (United States)

    Chai, Yangyang; Wang, Guibin; Fan, Lili; Zhao, Min

    2016-03-29

    The anti-tumor properties of fungal polysaccharides have gained significant recognition in Asia and tropical America. In this study, the differential expression of proteins in normal HepG2 cells and those treated with polysaccharides that had been isolated from Phellinus linteus (PL), Ganoderma lucidum (GL) and Auricularia auricula (AA) was investigated. Using two-dimensional electrophoresis (2DE), a total of 104 protein spots were determined to be overexpressed in these cells compared with noncancerous regions. A total of 59 differentially expressed proteins were identified through MALDI-TOF-MS. In addition, 400 biological processes (BP), 133 cell components (CC) and 146 molecular functions (MF) were enriched by Gene Ontology (GO) analysis, and 78 KEGG pathways were enriched by pathway enrichment. Protein-Protein Interaction (PPI) analysis demonstrated the interaction networks affected by polysaccharides in HepG2 cells. Then, DJ-1 and 14-3-3 were identified as the key proteins in the networks, and the expression of the mRNA and proteins were evaluated using Real-time quantitative PCR (qRT-PCR) and Western blotting (WB), respectively. The results were in agreement with the 2DE. These results provided information on significant proteins of hepatocellular carcinoma (HCC) and form an important basis for the future development of valuable medicinal mushroom resources.

  17. Insulin induces upregulation of vascular AT1 receptor gene expression by posttranscriptional mechanisms.

    Science.gov (United States)

    Nickenig, G; Röling, J; Strehlow, K; Schnabel, P; Böhm, M

    1998-12-01

    An interaction of insulin with angiotensin II effects could be pathophysiologically important for the pathogenesis of atherosclerosis and hypertension. We examined the effect of insulin on AT1 receptor gene expression in cultured vascular smooth muscle cells (VSMCs). A 24-hour incubation with insulin (100 nmol/L) produced a 2-fold increase in AT1 receptor density on VSMCs, as assessed by radioligand binding assays. This enhanced AT1 receptor expression was caused by a time- and concentration-dependent upregulation of the AT1 receptor mRNA levels, as assessed by Northern analysis. The maximal effect was detected after a 24-hour incubation of cells with 100 nmol/L insulin (270+/-20%). AT1 receptor upregulation was caused by a stabilization of the AT1 receptor mRNA, because the AT1 receptor mRNA half-life was prolonged from 5 hours under basal conditions to 10 hours after insulin stimulation. In contrast, insulin had no influence on AT1 receptor gene transcription, as assessed by nuclear run-on assays. The insulin-induced AT1 receptor upregulation was followed by an increased functional response, because angiotensin II evoked a significantly elevated intracellular release of calcium in cells that were preincubated with 100 nmol/L insulin for 24 hours. The insulin-induced AT1 receptor upregulation was dependent on tyrosine kinases, as assessed by experiments with the tyrosine kinase inhibitor genistein. Furthermore, experiments using the intracellular calcium chelator bis(2-amino-5-methylphenoxy)ethane-N, N,N',N'-tetraacetic acid tetraacetoxymethyl ester suggest that intracellular calcium release may be involved in AT1 receptor regulation. Insulin-induced upregulation of the AT1 receptor by posttranscriptional mechanisms may explain the association of hyperinsulinemia with hypertension and arteriosclerosis, because activation of the AT1 receptor plays a key role in the regulation of blood pressure and fluid homeostasis.

  18. Effect of annatto on micronuclei induction by direct and indirect mutagens in HepG2 cells.

    Science.gov (United States)

    Barcelos, Gustavo Rafael Mazzaron; Angeli, José Pedro Friedmann; Serpeloni, Juliana Mara; Rocha, Bruno Alves; Mantovani, Mário Sérgio; Antunes, Lusânia Maria Greggi

    2009-12-01

    Annatto (AN), a natural food colorant rich in carotenoids, has been reported as being an effective antioxidant, but little is known about its potential chemopreventive properties. In this study, we evaluated the ability of AN to protect human hepatoma cells (HepG2) from micronucleus (MN) induction against three different mutagens: benzo(a)pyrene (B(a)P), doxorubicin (DXR), and methyl methanesulfonate (MMS). In an attempt to clarify the possible mechanism of antimutagenicity of AN, three protocols of treatment were applied (pretreatment; simultaneous treatment, and post-treatment with AN following treatment with the mutagens). Also, cells exposed only to AN were assayed for cytotoxicity and mutagenicity. A dosage up to 10 microg/ml of AN was devoid of mutagenic activity. Protective effects were seen on micronuclei induced by B(a)P and DXR using pre and simultaneous treatment, but AN had no significant effect on MN induction by MMS in any of the protocols. Our results also show that exposure of cells to concentrations of AN higher than 10 microg/ml decreased cell viability. Taken together, our findings indicate that AN presents antimutagenic activity in vitro, but its protective effect is dependent on the mutagen and on type of treatment suggesting its potential use as a chemopreventive agent.

  19. Xanthohumol Suppresses Mylip/Idol Gene Expression and Modulates LDLR Abundance and Activity in HepG2 Cells.

    Science.gov (United States)

    Chen, Shih-Fen; Chen, Pei-Yi; Hsu, Hao-Jen; Wu, Ming-Jiuan; Yen, Jui-Hung

    2017-09-13

    Xanthohumol, a prenylated flavonoid found in hops (Humulus lupulus L.), exhibits multiple biological activities such as antiatherosclerosis and hypolipidemic activities. In this study, we aim to investigate the hypocholesterolemic effects and molecular mechanisms of xanthohumol in hepatic cells. We found that xanthohumol (10 and 20 μM) increased the amount of cell-surface low-density lipoprotein receptor (LDLR) from 100.0 ± 2.1% to 115.0 ± 1.3% and 135.2 ± 2.7%, and enhanced the LDL uptake activity from 100.0 ± 0.9% to 139.1 ± 13.2% in HepG2 cells (p Idol) mRNA and protein by approximately 45% (p Idol expression via counteracting liver X receptor (LXR) activation. The molecular docking results predicted that xanthohumol has a high binding affinity to interact with the LXRα ligand-binding domain, which may result in attenuation of LXRα-induced Mylip/Idol expression. Finally, we demonstrated that the Mylip/Idol expression and LDLR activity were synergistically changed by a combination of xanthohumol and simvastatin treatment. Our findings indicated that xanthohumol may regulate the LXR-Mylip/Idol axis to modulate hepatic LDLR abundance and activity.

  20. Hepatitis C virus (HCV) E1 and E2 protein regions that specifically bind to HepG2 cells.

    Science.gov (United States)

    Garcia, Javier Eduardo; Puentes, Alvaro; Súarez, Jorge; López, Ramses; Vera, Ricardo; Rodríguez, Luis Eduardo; Ocampo, Marisol; Curtidor, Hernando; Guzman, Fanny; Urquiza, Mauricio; Patarroyo, Manuel Elkin

    2002-02-01

    Identify hepatitis C virus (HCV) sequences in E1 and E2 protein binding to HepG2. Synthetic 20-mer long, ten-residue overlapped peptides, from E1 and E2 proteins, were tested in HepG2 or Raji cell-binding assays. Affinity constants, binding site number per cell and Hill coefficients were determined by saturation assay for high activity binding peptides (HABPs). Receptors for HepG2 cell were determined by cross-linking and sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis. Twelve HABPs were found in HCV genotype 1a, allowing six hepatocyte-binding sequences (HBSs) to be defined: two peptide-binding regions in E1 HABPs 4913 (YQVRNSTGLYHVTNDCPNSS) and 4918 (MTPTVATRDGKLPATQLRRHY). Four hepatocyte-binding regions were defined in E2: region-I, peptide 4931 (ETHVTGGSAGHTVSGFVSLLY); region-II, 4937-4939 (HHKFNSSGCPERLASCRPLTDFDQGWGPISYANGSGPDQR); region-III, 4943-4945 (PVYCFTPSPVVVGTTDRSGAPTYSWGENDTDVFVLNNTR) and region-IV, 4949-4952 (CGAPPCVIGGAGNNTLHCPTDCFRKHPDATYSRCGSGPWITPRCLVDYPY). The underlined sequences are most relevant in the binding process. HABPs 4913 and 4938 also bind to CD81 positive Raji cells. Region-II 4938 HABPs bind to 50 and 60kDa HepG2 cell membrane surface proteins. Six HVRs to the HepG2 were identified. Some HABPs have been previously found to be antigenic and immunogenic. HABPs, 4918 (from E1), 4938, 4949, 4950, 4951 and 4952 (from E2) have not been previously recognised. These HABPs could be relevant to HCV invasion of hepatocytes.

  1. Ananas comosus L. Leaf Phenols and p-Coumaric Acid Regulate Liver Fat Metabolism by Upregulating CPT-1 Expression

    Directory of Open Access Journals (Sweden)

    Weidong Xie

    2014-01-01

    Full Text Available In this study, we aimed to investigate the effect and action mechanisms of pineapple leaf phenols (PLPs on liver fat metabolism in high-fat diet-fed mice. Results show that PLP significantly reduced abdominal fat and liver lipid accumulation in high-fat diet-fed mice. The effects of PLP were comparable with those of FB. Furthermore, at the protein level, PLP upregulated the expression of carnitine palmitoyltransferase 1 (CPT-1, whereas FB had no effects on CPT-1 compared with the HFD controls. Regarding mRNA expression, PLP mainly promoted the expression of CPT-1, PGC1a, UCP-1, and AMPK in the mitochondria, whereas FB mostly enhanced the expression of Ech1, Acox1, Acaa1, and Ehhadh in peroxisomes. PLP seemed to enhance fat metabolism in the mitochondria, whereas FB mainly exerted the effect in peroxisomes. In addition, p-coumaric acid (CA, one of the main components from PLP, significantly inhibited fat accumulation in oleic acid-induced HepG2 cells. CA also significantly upregulated CPT-1 mRNA and protein expressions in HepG2 cells. We, firstly, found that PLP enhanced liver fat metabolism by upregulating CPT-1 expression in the mitochondria and might be promising in treatment of fatty liver diseases as alternative natural products. CA may be one of the active components of PLP.

  2. Differential toxicity of Disperse Red 1 and Disperse Red 13 in the Ames test, HepG2 cytotoxicity assay, and Daphnia acute toxicity test.

    Science.gov (United States)

    Ferraz, E R A; Umbuzeiro, G A; de-Almeida, G; Caloto-Oliveira, A; Chequer, F M D; Zanoni, M V B; Dorta, D J; Oliveira, D P

    2011-10-01

    Azo dyes are of environmental concern due to their degradation products, widespread use, and low-removal rate during conventional treatment. Their toxic properties are related to the nature and position of the substituents with respect to the aromatic rings and amino nitrogen atom. The dyes Disperse Red 1 and Disperse Red 13 were tested for Salmonella mutagenicity, cell viability by annexin V, and propidium iodide in HepG2 and by aquatic toxicity assays using daphnids. Both dyes tested positive in the Salmonella assay, and the suggestion was made that these compounds induce mainly frame-shift mutations and that the enzymes nitroreductase and O-acetyltransferase play an important role in the observed effect. In addition, it was shown that the presence of the chlorine substituent in Disperse Red 13 decreased the mutagenicity about 14 times when compared with Disperse Red 1, which shows the same structure as Disperse Red 13, but without the chlorine substituent. The presence of this substituent did not cause cytotoxicity in HepG2 cells, but toxicity to the water flea Daphnia similis increased in the presence of the chlorine substituent. These data suggest that the insertion of a chlorine substituent could be an alternative in the design of dyes with low-mutagenic potency, although the ecotoxicity should be carefully evaluated. Copyright © 2010 Wiley Periodicals, Inc.

  3. Cytotoxic, genotoxic and biochemical markers of insecticide toxicity evaluated in human peripheral blood lymphocytes and an HepG2 cell line.

    Science.gov (United States)

    Želježić, Davor; Mladinić, Marin; Žunec, Suzana; Lucić Vrdoljak, Ana; Kašuba, Vilena; Tariba, Blanka; Živković, Tanja; Marjanović, Ana Marija; Pavičić, Ivan; Milić, Mirta; Rozgaj, Ružica; Kopjar, Nevenka

    2016-10-01

    This study evaluated the cyto- and genotoxic effects of three pesticides: α-cypermethrin, chlorpyrifos and imidacloprid applied in vitro to human lymphocytes and HepG2 cells for exposure times of 4 and 24 h at concentrations corresponding to OEL, ADI and REL. Assessments were made using oxidative stress biomarkers and the alkaline comet, cytokinesis-block micronucleus cytome and cell viability assays. Low doses of all three pesticides displayed DNA damaging potential, both in lymphocytes and HepG2 cells. At the tested concentrations, all three compounds induced lymphocyte apoptosis, though α-cypermethrin and chlorpyrifos were generally more cyto- and genotoxic than imidacloprid. At the tested concentrations, oxidative stress biomarkers were not significantly altered, and the effects mediated indirectly through free radicals may not have a key role in the formation of DNA damage. It is likely that the DNA damaging effects were caused by direct interactions between the tested compounds and/or their metabolites that destabilized the DNA structure. The tested pesticides had the potential for MN, NB and NPB formation and to disturb cell cycle kinetics in both cell types. There were also indications that exposure to α-cypermethrin led to the formation of crosslinks in DNA, though this would require more detailed study in the future. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Characterization of dengue virus entry into HepG2 cells

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    Suksanpaisan Lukkana

    2009-02-01

    Full Text Available Abstract Background Despite infections by the dengue virus being a significant problem in tropical and sub-tropical countries, the mechanism by which the dengue virus enters into mammalian cells remains poorly described. Methods A combination of biochemical inhibition, dominant negative transfection of Eps15 and siRNA mediated gene silencing was used to explore the entry mechanism of dengue into HepG2 cells. Results Results were consistent with entry via multiple pathways, specifically via clathrin coated pit mediated endocytosis and macropinocytosis, with clathrin mediated endocytosis being the predominant pathway. Conclusion We propose that entry of the dengue virus to mammalian cells can occur by multiple pathways, and this opens the possibility of the virus being directed to multiple cellular compartments. This would have significant implications in understanding the interaction of the dengue virus with the host cell machinery.

  5. Effects of elaidic acid in a HepG2-SF liver cell model

    DEFF Research Database (Denmark)

    Hansen, Toke Peter Krogager

    Det primære mål for dette Ph.D-studie var at identificere potentielle proteinbiomarkører for menneskelig indtagelse af elaidinsyre, hvilken er den mest almindelige transfedtsyre i fødevarer. En serum fri HepG2 celle model (HepG-SF) blev inkuberet i syv dage med elaidinsyre eller med andre...... human blodplasma. Det sekundære mål for Ph.D-studiet var at undersøge årsagerne til den specifikke cellulære respons for elaidinsyre. Det blev observeret at inkubation med elaidinsyre resulterede i at 28 % af de esterficerede fedtsyrerne i fosfolipid-fraktionen var elaidinsyre, hvilket indikerer en...

  6. STARD4 knockdown in HepG2 cells disrupts cholesterol trafficking associated with the plasma membrane, ER, and ERC

    DEFF Research Database (Denmark)

    Garbarino, J.; Pan, M. H.; Chin, H. F.

    2012-01-01

    small hairpin RNA knockdown technology to reduce STARD4 expression in HepG2 cells. In a cholesterol-poor environment, we found that a reduction in STARD4 expression leads to retention of cholesterol at the plasma membrane, reduction of endoplasmic reticulum-associated cholesterol, and decreased ACAT...... membrane and the endocytic recycling compartment to the endoplasmic reticulum and perhaps other intracellular compartments as well. -Garbarino, J., M. Pan, H.F. Chin, F.W. Lund, F.R. Maxfield, and J.L. Breslow. STARD4 knockdown in HepG2 cells disrupts cholesterol trafficking associated with the plasma...

  7. Data on HepG2 cells changes following exposure to cadmium sulphide quantum dots (CdS QDs

    Directory of Open Access Journals (Sweden)

    Laura Paesano

    2017-04-01

    Full Text Available The data included in this paper are associated with the research article entitled "Markers for toxicity to HepG2 exposed to cadmium sulphide quantum dots; damage to mitochondria" (Paesano et al. [1]. The article concerns the cytotoxic and genotoxic effects of CdS QDs in HepG2 cells and the mechanisms involved. In this dataset, changes in expression levels of candidate genes are reported, together with details concerning synthesis and properties of CdS QDs, additional information obtained through literature survey, measures of the mitochondrial membrane potential and the glutathione redox state.

  8. Lutein Induces Autophagy via Beclin-1 Upregulation in IEC-6 Rat Intestinal Epithelial Cells.

    Science.gov (United States)

    Chang, Chi-Jen; Lin, Ji-Fan; Hsiao, Chien-Yu; Chang, Hsun-Hao; Li, Hsin-Ju; Chang, Hsun-Hsien; Lee, Gon-Ann; Hung, Chi-Feng

    2017-01-01

    Lutein is a carotenoid with anti-oxidant properties. Autophagy, an evolutionarily conserved catabolic cellular pathway for coping with stress conditions, is responsive to reactive oxygen species (ROS) and degrades damaged organelles. We previously demonstrated that lutein can induce anti-oxidant enzymes to relieve methotrexate-induced ROS stress. We therefore hypothesized that lutein, which activates ROS-scavenging enzymes, can also induce autophagy for cell survival. In this study, we demonstrated that lutein treatment attenuated the reduction in cell viability caused by H 2 O 2 . Lutein dose-dependently induced the processing of microtubule-associated protein light chain 3 (LC3)-II, an autophagy marker protein, and accumulation of LC3-positive puncta in rat intestinal IEC-6 cells. Furthermore, (a) direct observation of autophagosome formation through transmission electron microscopy, (b) upregulation of autophagy-related genes including ATG4A, ATG5, ATG7, ATG12, and beclin-1 (BENC1), and (c) increased BECN1/Bcl-2 ratio confirmed the induction of autophagy by lutein. The results revealed that bafilomycin-A1-induced inhibition of autophagy reduced cell viability and increased apoptosis in lutein-treated cells, indicating a protective role of lutein-induced autophagy. Lutein treatment also activated adenosine monophosphate-activated protein kinase (AMPK), c-Jun N-terminal kinase (JNK), and p-38, but had no effects on the induction of extracellular signal-related kinase or inhibition of mTOR; however, the inhibition of activated AMPK, JNK, or p-38 did not attenuate lutein-induced autophagy. Finally, increased BECN1 expression levels were detected in lutein-treated cells, and BECN1 knockdown abolished autophagy induction. These results suggest that lutein-induced autophagy was mediated by the upregulation of BECN1 in IEC-6 cells. We are the first to demonstrate that lutein induces autophagy. Elevated autophagy in lutein-treated IEC-6 cells may have a protective role

  9. Upregulation of FOXM1 induces genomic instability in human epidermal keratinocytes

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    Philpott Michael P

    2010-02-01

    Full Text Available Abstract Background The human cell cycle transcription factor FOXM1 is known to play a key role in regulating timely mitotic progression and accurate chromosomal segregation during cell division. Deregulation of FOXM1 has been linked to a majority of human cancers. We previously showed that FOXM1 was upregulated in basal cell carcinoma and recently reported that upregulation of FOXM1 precedes malignancy in a number of solid human cancer types including oral, oesophagus, lung, breast, kidney, bladder and uterus. This indicates that upregulation of FOXM1 may be an early molecular signal required for aberrant cell cycle and cancer initiation. Results The present study investigated the putative early mechanism of UVB and FOXM1 in skin cancer initiation. We have demonstrated that UVB dose-dependently increased FOXM1 protein levels through protein stabilisation and accumulation rather than de novo mRNA expression in human epidermal keratinocytes. FOXM1 upregulation in primary human keratinocytes triggered pro-apoptotic/DNA-damage checkpoint response genes such as p21, p38 MAPK, p53 and PARP, however, without causing significant cell cycle arrest or cell death. Using a high-resolution Affymetrix genome-wide single nucleotide polymorphism (SNP mapping technique, we provided the evidence that FOXM1 upregulation in epidermal keratinocytes is sufficient to induce genomic instability, in the form of loss of heterozygosity (LOH and copy number variations (CNV. FOXM1-induced genomic instability was significantly enhanced and accumulated with increasing cell passage and this instability was increased even further upon exposure to UVB resulting in whole chromosomal gain (7p21.3-7q36.3 and segmental LOH (6q25.1-6q25.3. Conclusion We hypothesise that prolonged and repeated UVB exposure selects for skin cells bearing stable FOXM1 protein causes aberrant cell cycle checkpoint thereby allowing ectopic cell cycle entry and subsequent genomic instability. The aberrant

  10. Wedelolactone Regulates Lipid Metabolism and Improves Hepatic Steatosis Partly by AMPK Activation and Up-Regulation of Expression of PPARα/LPL and LDLR.

    Directory of Open Access Journals (Sweden)

    Yun Zhao

    Full Text Available Hyperlipidemia is considered one of the greatest risk factors of cardiovascular diseases. We investigated the anti-hyperlipidemic effect and the underlying mechanism of wedelolactone, a plant-derived coumestan, in HepG2 cells and high-fat diet (HFD-induced hyperlipidemic hamsters. We showed that in cultured HepG2 cells, wedelolactone up-regulated protein levels of adenosine monophosphate activated protein kinase (AMPK and peroxisome proliferator-activated receptor-alpha (PPARα as well as the gene expression of AMPK, PPARα, lipoprotein lipase (LPL, and the low-density lipoprotein receptor (LDLR. Meanwhile, administration of wedelolactone for 4 weeks decreased the lipid profiles of plasma and liver in HFD-induced hyperlipidemic hamsters, including total cholesterol (TC, triglycerides (TG, and low-density lipoprotein-cholesterol (LDL-C. The activation of AMPK and up-regulation of PPARα was also observed with wedelolactone treatment. Furthermore, wedelolactone also increased the activities of superoxidase dismutase (SOD and glutathione peroxidase (GSH-Px and decreased the level of the lipid peroxidation product malondialdehyde (MDA in the liver, therefore decreasing the activity of alanine aminotransferase (ALT. In conclusion, we provide novel experimental evidence that wedelolactone possesses lipid-lowering and steatosis-improving effects, and the underlying mechanism is, at least in part, mediated by the activation of AMPK and the up-regulation of PPARα/LPL and LDLR.

  11. Chronic Fluoxetine Treatment Induces Brain Region-Specific Upregulation of Genes Associated with BDNF-Induced Long-Term Potentiation

    Directory of Open Access Journals (Sweden)

    Maria Nordheim Alme

    2007-01-01

    Full Text Available Several lines of evidence implicate BDNF in the pathogenesis of stress-induced depression and the delayed efficacy of antidepressant drugs. Antidepressant-induced upregulation of BDNF signaling is thought to promote adaptive neuronal plasticity through effects on gene expression, but the effector genes downstream of BDNF has not been identified. Local infusion of BDNF into the dentate gyrus induces a long-term potentiation (BDNF-LTP of synaptic transmission that requires upregulation of the immediate early gene Arc. Recently, we identified five genes (neuritin, Narp, TIEG1, Carp, and Arl4d that are coupregulated with Arc during BDNF-LTP. Here, we examined the expression of these genes in the dentate gyrus, hippocampus proper, and prefrontal cortex after antidepressant treatment. We show that chronic, but not acute, fluoxetine administration leads to upregulation of these BDNF-LTP-associated genes in a brain region-specific pattern. These findings link chronic effects of antidepressant treatment to molecular mechanisms underlying BDNF-induced synaptic plasticity.

  12. Cell stress induces upregulation of osteopontin via the ERK pathway in type II alveolar epithelial cells.

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    Aki Kato

    Full Text Available Osteopontin (OPN is a multifunctional protein that plays important roles in cell growth, differentiation, migration and tissue fibrosis. In human idiopathic pulmonary fibrosis and murine bleomycin-induced lung fibrosis, OPN is upregulated in type II alveolar epithelial cells (AEC II. However, the mechanism of OPN induction in AEC II is not fully understood. In this study, we demonstrate the molecular mechanism of OPN induction in AEC II and elucidate the functions of OPN in AEC II and lung fibroblasts. Human lung adenocarcinoma cells (A549 and mouse alveolar epithelial cells (MLE12, used as type II alveolar epithelial cell lines for in vitro assays, and human pulmonary alveolar epithelial cells (HPAEpiC were treated with either bleomycin, doxorubicin or tunicamycin. The mechanism of OPN induction in these cells and its function as a pro-fibrotic cytokine on A549 and lung fibroblasts were analyzed. The DNA damaging reagents bleomycin and doxorubicin were found to induce OPN expression in A549, MLE12 and HPAEpiC. OPN expression was induced via activation of the extracellular signal-regulated protein kinase (ERK-dependent signaling pathway in A549 and MLE12. The endoplasmic reticulum (ER stress-inducing reagent tunicamycin induced OPN mRNA expression in A549, MLE12 and HPAEpiC, and OPN mRNA expression was induced via activation of the ERK-dependent signaling pathway in A549 and MLE12. Another ER stress-inducing reagent thapsigargin induced the expression of OPN mRNA as well as the subsequent production of OPN in A549 and MLE12. Furthermore, OPN promoted the proliferation of A549 and the migration of normal human lung fibroblasts. Inhibition of OPN by small interference RNA or neutralizing antibody suppressed both of these responses. The results of this study suggest that cell stress induces the upregulation of OPN in AEC II by signaling through the ERK pathway, and that upregulated OPN may play a role in fibrogenesis of the lung.

  13. Mutations in BALB mitochondrial DNA induce CCL20 up-regulation promoting tumorigenic phenotypes

    Energy Technology Data Exchange (ETDEWEB)

    Sligh, James [Department of Medicine—Dermatology Division, University of Arizona, Tucson, AZ 857 24 (United States); University of Arizona Cancer Center, Tucson, AZ 85724 (United States); Janda, Jaroslav [University of Arizona Cancer Center, Tucson, AZ 85724 (United States); Jandova, Jana, E-mail: jjandova@email.arizona.edu [Department of Medicine—Dermatology Division, University of Arizona, Tucson, AZ 857 24 (United States); University of Arizona Cancer Center, Tucson, AZ 85724 (United States)

    2014-11-15

    Highlights: • Alterations in mitochondrial DNA are commonly found in various human cancers. • Mutations in BALB mitochondrial DNA induce up-regulation of chemokine CCL20. • Increased growth and motility of mtBALB cells is associated with CCL20 levels. • mtDNA changes in BALB induce in vivo tumor growth through CCL20 up-regulation. • Mutations in mitochondrial DNA play important roles in keratinocyte neoplasia. - Abstract: mtDNA mutations are common in human cancers and are thought to contribute to the process of neoplasia. We examined the role of mtDNA mutations in skin cancer by generating fibroblast cybrids harboring a mutation in the gene encoding the mitochondrial tRNA for arginine. This somatic mutation (9821insA) was previously reported in UV-induced hyperkeratotic skin tumors in hairless mice and confers specific tumorigenic phenotypes to mutant cybrids. Microarray analysis revealed and RT-PCR along with Western blot analysis confirmed the up-regulation of CCL20 and its receptor CCR6 in mtBALB haplotype containing the mt-Tr 9821insA allele compared to wild type mtB6 haplotype. Based on reported role of CCL20 in cancer progression we examined whether the hyper-proliferation and enhanced motility of mtBALB haplotype would be associated with CCL20 levels. Treatment of both genotypes with recombinant CCL20 (rmCCL20) resulted in enhanced growth and motility of mtB6 cybrids. Furthermore, the acquired somatic alteration increased the in vivo tumor growth of mtBALB cybrids through the up-regulation of CCL20 since neutralizing antibody significantly decreased in vivo tumor growth of these cells; and tumors from anti-CCL20 treated mice injected with mtBALB cybrids showed significantly decreased CCL20 levels. When rmCCL20 or mtBALB cybrids were used as chemotactic stimuli, mtB6 cybrids showed increased motility while anti-CCL20 antibody decreased the migration and in vivo tumor growth of mtBALB cybrids. Moreover, the inhibitors of MAPK signaling and NF

  14. Inhibin beta E is upregulated by drug-induced endoplasmic reticulum stress as a transcriptional target gene of ATF4

    Energy Technology Data Exchange (ETDEWEB)

    Brüning, Ansgar, E-mail: ansgar.bruening@med.uni-muenchen.de; Matsingou, Christina; Brem, German Johannes; Rahmeh, Martina; Mylonas, Ioannis

    2012-10-15

    Inhibins and activins are gonadal peptide hormones of the transforming growth factor-β super family with important functions in the reproductive system. By contrast, the recently identified inhibin βE subunit, primarily expressed in liver cells, appears to exert functions unrelated to the reproductive system. Previously shown downregulation of inhibin βE in hepatoma cells and anti-proliferative effects of ectopic inhibin βE overexpression indicated growth-regulatory effects of inhibin βE. We observed a selective re-expression of the inhibin βE subunit in HepG2 hepatoblastoma cells, MCF7 breast cancer cells, and HeLa cervical cancer cells under endoplasmic reticulum stress conditions induced by tunicamycin, thapsigargin, and nelfinavir. Analysis of XPB1 splicing and ATF4 activation revealed that inhibin βE re-expression was associated with induction of the endoplasmic reticulum stress reaction by these drugs. Transfection of an ATF4 expression plasmid specifically induced inhibin βE expression in HeLa cells and indicates inhibin βE as a hitherto unidentified target gene of ATF4, a key transcription factor of the endoplasmic reticulum stress response. Therefore, the inhibin βE subunit defines not only a new player but also a possible new marker for drug-induced endoplasmic reticulum stress. -- Highlights: ► Endoplasmic reticulum stress induces inhibin beta E expression. ► Inhibin beta E is regulated by the transcription factor ATF4. ► Inhibin beta E expression can be used as a marker for drug-induced ER stress.

  15. Shifts in dietary carbohydrate-lipid exposure regulate expression of the non-alcoholic fatty liver disease-associated gene PNPLA3/adiponutrin in mouse liver and HepG2 human liver cells.

    Science.gov (United States)

    Hao, Lei; Ito, Kyoko; Huang, Kuan-Hsun; Sae-tan, Sudathip; Lambert, Joshua D; Ross, A Catharine

    2014-10-01

    Patatin-like phospholipase domain containing 3 (PNPLA3, adiponutrin) has been identified as a modifier of lipid metabolism. To better understand the physiological role of PNPLA3/adiponutrin, we have investigated its regulation in intact mice and human hepatocytes under various nutritional/metabolic conditions. PNPLA3 gene expression was determined by real-time PCR in liver of C57BL/6 mice after dietary treatments and in HepG2 cells exposed to various nutritional/metabolic stimuli. Intracellular lipid content was determined in HepG2 cells after siRNA-mediated knockdown of PNPLA3. In vivo, mice fed a high-carbohydrate (HC) liquid diet had elevated hepatic lipid content, and PNPLA3 mRNA and protein expression, compared to chow-fed mice. Elevated expression was completely abrogated by addition of unsaturated lipid emulsion to the HC diet. By contrast, in mice with high-fat diet-induced steatosis, Pnpla3 expression did not differ compared to low-fat fed mice. In HepG2 cells, Pnpla3 expression was reversibly suppressed by glucose depletion and increased by glucose refeeding, but unchanged by addition of insulin and glucagon. Several unsaturated fatty acids each significantly decreased Pnpla3 mRNA, similar to lipid emulsion in vivo. However, Pnpla3 knockdown in HepG2 cells did not alter total lipid content in high glucose- or oleic acid-treated cells. Our results provide evidence that PNPLA3 expression is an early signal/signature of carbohydrate-induced lipogenesis, but its expression is not associated with steatosis per se. Under lipogenic conditions due to high-carbohydrate feeding, certain unsaturated fatty acids can effectively suppress both lipogenesis and PNPLA3 expression, both in vivo and in a hepatocyte cell line. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Antiproliferative activity of vitexin-2-O-xyloside and avenanthramides on CaCo-2 and HepG2 cancer cells occurs through apoptosis induction and reduction of pro-survival mechanisms.

    Science.gov (United States)

    Scarpa, Emanuele Salvatore; Antonini, Elena; Palma, Francesco; Mari, Michele; Ninfali, Paolino

    2017-03-10

    CaCo-2 colon cancer cells and HepG2 liver cancer cells represent two malignant cell lines, which show a high resistance to apoptosis induced by the conventional anticancer drugs. Vitexin-2-O-xyloside (XVX) and avenanthramides (AVNs) are naturally occurring dietary agents from Beta vulgaris var. cicla L. and Avena sativa L., respectively. The aim of this work was to evaluate the antiproliferative effects and the reduction of the pro-survival mechanisms exerted by XVX and AVNs, used individually and in combination, in CaCo-2 and HepG2 cancer cells. XVX and AVNs were isolated by liquid chromatography and characterized by HPLC-PDA-MS. The XVX and AVN antiproliferative effects were evaluated through sulforhodamine B method, while their pro-apoptotic effects through caspase activity assays. RTqPCR was used to investigate the modulation of the pro-survival factors baculoviral inhibitor of apoptosis repeat-containing 5 (BIRC5), hypoxia inducible factor 1 A (HIF1A), and vascular endothelial growth factor A (VEGFA). Cellular antioxidant activity (CAA) was investigated by means of DCFH-DA assay, whereas chemical antioxidant capacity was evaluated by the ORAC method. XVX and AVNs, both individually and in combination, inhibited the proliferation of CaCo-2 and HepG2 cancer cells, through activation of caspases 9, 8, and 3. XVX and AVNs downregulated the pro-survival genes BIRC5, HIF1A, and VEGFA. The CAA assay showed that AVNs exhibited strong antioxidant activity inside both CaCo-2 and HepG2 cells. The antiproliferative activity of the XVX + AVNs mixture represents an innovative treatment, which is effective against two types of cancer cells characterized by high resistance to the conventional anticancer drugs.

  17. miR-203a is involved in HBx-induced inflammation by targeting Rap1a

    Energy Technology Data Exchange (ETDEWEB)

    Wu, AiRong [Department of gastroenterology, The First affiliated Hospital of Soochow University, Suzhou 215006 (China); Chen, Huo [Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123 (China); Xu, ChunFang [Department of gastroenterology, The First affiliated Hospital of Soochow University, Suzhou 215006 (China); Zhou, Ji; Chen, Si [Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123 (China); Shi, YuQi [Department of gastroenterology, The First affiliated Hospital of Soochow University, Suzhou 215006 (China); Xu, Jie [Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123 (China); Gan, JianHe, E-mail: j_pzhang@suda.edu.cn [Department of gastroenterology, The First affiliated Hospital of Soochow University, Suzhou 215006 (China); Zhang, JinPing, E-mail: ganjianhe@aliyun.com [Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123 (China)

    2016-11-15

    Hepatitis B virus (HBV) causes acute and chronic hepatitis, and is one of the major causes of cirrhosis and hepatocellular carcinoma. Accumulating evidence suggests that inflammation is the key factor for liver cirrhosis and hepatocellular carcinoma. MicroRNAs play important roles in many biological processes. Here, we aim to explore the function of microRNAs in the HBX-induced inflammation. First, microarray experiment showed that HBV{sup +} liver samples expressed higher level of miR-203a compared to HBV{sup -} liver samples. To verify these alterations, HBx-coding plasmid was transfected into HepG2 cells to overexpress HBx protein. The real-time PCR results suggested that over-expression of HBx could induce up-regulation of miR-203a. To define how up-regulation of miR-203a can induce liver cells inflammation, we over-expressed miR-203a in HepG2 cells. Annexin V staining and BrdU staining suggested that overexpression of miR-203a significantly increased the cell apoptosis and proliferation, meanwhile, over-expression of miR-203a could lead to a decrease in G0/G1 phase cells and an increase in G2/M phase cells. Some cytokines production including IL-6 and IL-8 were significantly increased, but TGFβ and IFNγ were decreased in miR-203a over-expressed HepG2 cells. Luciferase reporter assay experiments, protein mass-spectrum assay and real-time PCR all together demonstrated that Rap1a was the target gene of miR-203a. Further experiments showed that these alterations were modulated through PI3K/ERK/p38/NFκB pathways. These data suggested that HBV-infection could up-regulate the expression of miR-203a, thus down regulated the expression of Rap1a and affected the PI3K/ERK/p38/NFκB pathways, finally induced the hepatitis inflammation. - Highlights: • HBX induces the over-expression of miR-203a in HepG2 cells. • miR-203a targets Rap1a to induce the inflammation in HepG2 cells. • miR-203a regulates the apoptosis and cell cycles of HepG2 cells. • miR-203a alters

  18. Atorvastatin and fenofibrate increase apolipoprotein AV and decrease triglycerides by up-regulating peroxisome proliferator-activated receptor-α

    Science.gov (United States)

    Huang, Xian-sheng; Zhao, Shui-ping; Bai, Lin; Hu, Min; Zhao, Wang; Zhang, Qian

    2009-01-01

    Background and purpose: Combining statin and fibrate in clinical practice provides a greater reduction of triglycerides than either drug given alone, but the mechanism for this effect is poorly understood. Apolipoprotein AV (apoAV) has been implicated in triglyceride metabolism. This study was designed to investigate the effect of the combination of statin and fibrate on apoAV and the underlying mechanism(s). Experimental approach: Hypertriglyceridaemia was induced in rats by giving them 10% fructose in drinking water for 2 weeks. They were then treated with atorvastatin, fenofibrate or the two agents combined for 4 weeks, and plasma triglyceride and apoAV measured. We also tested the effects of these two agents on triglycerides and apoAV in HepG2 cells in culture. Western blot and reverse transcription polymerase chain reaction was used to measure apoAV and peroxisome proliferator-activated receptor-α (PPARα) expression. Key results: The combination of atorvastatin and fenofibrate resulted in a greater decrease in plasma triglycerides and a greater increase in plasma and hepatic apoAV than either agent given alone. Hepatic expression of the PPARα was also more extensively up-regulated in rats treated with the combination. A similar, greater increase in apoAV and a greater decrease in triglycerides were observed following treatment of HepG2 cells pre-exposed to fructose), with the combination. Adding an inhibitor of PPARα (MK886) abolished the effects of atorvastatin on HepG2 cells. Conclusions and implications: A combination of atorvastatin and fenofibrate increased apoAV and decreased triglycerides through up-regulation of PPARα. PMID:19694729

  19. Mannose 6-phosphate-independent targeting of cathepsin D to lysosomes in HepG2 cells

    NARCIS (Netherlands)

    Rijnboutt, S.; Kal, A. J.; Geuze, H. J.; Aerts, H.; Strous, G. J.

    1991-01-01

    We have studied the role of N-linked oligosaccharides and proteolytic processing on the targeting of cathepsin D to the lysosomes in the human hepatoma cell line HepG2. In the presence of tunicamycin cathepsin D was synthesized as an unglycosylated 43-kDa proenzyme which was proteolytically

  20. Biochemical Effects of six Ti02 and four Ce02 Nanomaterials in HepG2 cells

    Science.gov (United States)

    Abstract The potential mammalian hepatotoxicity of nanomaterials were explored in dose-response and structure-activity studies with human hepatic HepG2 cells exposed to between 10 and 1000 ug/ml of six different TiO2 and four CeO2 nanomaterials for 3 days. Var...

  1. Effects of the radiolysis products of sennoside A on HepG2 and PC-3 cell

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Ho; Jo, Min Ho [Research Division for Biotechnology, Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2016-11-15

    Radiolysis of sennoside A was carried out by gamma irradiation and the anti-cancer activities of the radiolysis product were evaluated. An aqueous solution of sennoside A was exposed to 0.5-3 kGy of gamma irradiation and the radiolysis products were analyzed by HPLC. A fraction of radiolysis product (RLF) of sennoside A was isolated and the RLF was presumed as a rhein-8-β-D-glucoside. The anticancer effect of the RLF was compared with the sennoside and rhein using a in vitro assay system of human prostate cancer cells (PC-3) and human hepatoma HepG2 cells. The cell viability of PC-3 and HepG2 cell was significantly decreased to 12.4±1.2% and 32.4±2.1%, respectively, by the treatment of 0.6 μM of RLF. The sennoside A (range from 0 to 25 μM) had no cytotoxic effect on PC-3 and HepG2 cells, while the rhein had the effect on HepG2 cells with a LD{sub 50} at 80 μM.

  2. Oncostatin M regulates membrane traffic and stimulates bile canalicular membrane biogenesis in HepG2 cells

    NARCIS (Netherlands)

    Van der Wouden, Johanna M.; Van IJzendoorn, Sven C.D.; Hoekstra, Dick

    2002-01-01

    Hepatocytes are the major epithelial cells of the liver and they display membrane polarity: the sinusoidal membrane representing the basolateral surface, while the bile canalicular membrane is typical of the apical membrane. In polarized HepG2 cells an endosomal organelle, SAC, fulfills a prominent

  3. Effect of Tumor Microenvironment on Selective Uptake of Boric Acid in HepG2 Human Hepatoma Cells.

    Science.gov (United States)

    Bai, Yu-Chi; Hsia, Yu-Chun; Lin, Yu-Ting; Chen, Kuan-Hao; Chou, Fong-In; Yang, Chia-Min; Chuang, Yung-Jen

    2017-11-01

    Feasibility and efficacy of boric acid (BA)-mediated boron neutron capture therapy (BNCT) was first demonstrated by eliminating hepatocellular carcinoma (HCC) in a rat model. Furthermore, selective uptake of BA by liver tumor cells was shown in a rabbit model. To gain further insight, this study aimed to investigate the mechanisms of transportation and selective uptake of BA in HepG2 liver tumor cells. Transportation of BA in HepG2 cells was analyzed by time-course assays and by analyzing the rate of diffusion versus the concentration of BA. The effect of different tumor conditions on BA uptake was studied by treating HepG2 cells with 25 μg (10)B/ml BA under different concentrations of glucose, at different pH and in the presence of water-soluble cholesterol. HepG2 cells mainly uptake BA by simple diffusion. Cell membrane permeability may also contribute to tumor-specific uptake of BA. The selective uptake of BA was achieved primarily by diffusion, while other factors, such as low pH and increased membrane fluidity, which are hallmarks of HCC, might further enhance BA uptake. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  4. Ski diminishes TGF-β1-induced myofibroblast phenotype via up-regulating Meox2 expression.

    Science.gov (United States)

    Chen, Zhaowei; Li, Wenjing; Ning, Yan; Liu, Tong; Shao, Jingxiang; Wang, Yaojun

    2014-12-01

    The aim of the present work was to investigate the mechanism of transforming growth factor (TGF)-β1 and Sloan-Kettering Institute (Ski) in the pathogenesis of hypertrophic scars (HS). Wound healing is an inherent process, but the aberrant wound healing of skin injury may lead to HS. There has been growing evidence suggesting a role for TGF-β1 and Ski in the pathogenesis of fibrosis. The MTT assay was used to detect the cell proliferation induced by TGF-β1. The Ski gene was transduced into cells with an adenovirus, and then the function of Ski in cell proliferation and differentiation was observed. Ski mRNA levels were measured by RT-PCR. Western blotting was used to detect the protein expression of α-SMA, E-cadherin, Meox1, Meox2, Zeb1 and Zeb2. TGF-β1 can promote human skin fibroblast (HSF) cell proliferation in a time-dependent manner, but the promoting effect could be suppressed by Ski. TGF-β1 also induces the formation of the myofibroblast phenotype and the effect of TGF-β1 could be diminished by Ski. Also, Ski modulates the cardiac myofibroblast phenotype and function through suppression of Zeb2 by up-regulating the expression of Meox2. Ski diminishes the myofibroblast phenotype induced by TGF-β1 through the suppression of Zeb2 by up-regulating the expression of Meox2. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Aegle marmelos differentially affects hepatic markers of glycolysis, insulin signalling pathway, hypoxia, and inflammation in HepG2 cells grown in fructose versus glucose-rich environment.

    Science.gov (United States)

    Aggarwal, H; Nair, J; Sharma, P; Sehgal, R; Naeem, U; Rajora, P; Mathur, R

    2017-08-01

    Fructose consumption is responsible for the onset of insulin resistance (IR), and metabolic syndrome. It possesses no functional utility in body and its detrimental effects on hepatic metabolic milieu are beyond those produced by glucose. The need of the hour is to identify fructose-induced IR as an unique pathological state to be managed differentially. The effect of aqueous leaf extract of Aegle marmelos (AM) on hepatic markers of insulin resistance using HepG2 cells cultured in either fructose or glucose-rich environment is investigated. Human hepatocellular carcinoma cells (HepG2) were grown under standard conditions in either-DMEM without glucose (NC), DMEM with high glucose 25 mM (Glu), DMEM-glucose+0.55 mM fructose (FC1), DMEM-glucose+1 mM fructose (FC2) or DMEM-glucose+1 mM fructose+0.1 µM insulin (FC3). The cells were treated with either AM, rutin, quercetin, metformin or pioglitazone and assessed for levels of hexokinase, phosphofructokinase (PFK), aldehyde dehydrogenase, phosphatidylinositol kinase (PI3K), signal transducer and activator of transcription-3 (STAT-3), mitochondrial target of rapamycin (mTOR), hypoxia-induced factor (HIF-1α), vascular endothelial growth factor (VEGF) and tumour necrosis factor (TNF-α). Summarily, when results from fructose- and glucose-rich environment were compared, then (1) IR was more pronounced in former; (2) AM performed better in former; (3) metformin and pioglitazone were equivocal in either; (4) rutin and quercetin showed deviant effects from AM; and lastly (5) effects of rutin were closer to AM than quercetin. We hypothesize that AM ameliorates fructose-induced IR through a mechanism which is distinct from standard drugs and not shared by individual phytoconstituents in toto.

  6. Ginseng (Panax quinquefolius and Licorice (Glycyrrhiza uralensis Root Extract Combinations Increase Hepatocarcinoma Cell (Hep-G2 Viability

    Directory of Open Access Journals (Sweden)

    David G. Popovich

    2011-01-01

    Full Text Available The combined cytoactive effects of American ginseng (Panax quinquefolius and licorice (Glycyrrhiza uralensis root extracts were investigated in a hepatocarcinoma cell line (Hep-G2. An isobolographic analysis was utilized to express the possibility of synergistic, additive or antagonistic interaction between the two extracts. Both ginseng and licorice roots are widely utilized in traditional Chinese medicine preparations to treat a variety of ailments. However, the effect of the herbs in combination is currently unknown in cultured Hep-G2 cells. Ginseng (GE and licorice (LE extracts were both able to reduce cell viability. The LC50 values, after 72 h, were found to be 0.64 ± 0.02 mg/mL (GE and 0.53 ± 0.02 mg/mL (LE. An isobologram was plotted, which included five theoretical LC50s calculated, based on the fixed fraction method of combination ginseng to licorice extracts to establish a line of additivity. All combinations of GE to LE (1/5, 1/3, 1/2, 2/3, 4/5 produced an effect on Hep-G2 cell viability but they were all found to be antagonistic. The LC50 of fractions 1/3, 1/2, 2/3 were 23%, 21% and 18% above the theoretical LC50. Lactate dehydrogenase release indicated that as the proportion of GE to LE increased beyond 50%, the influence on membrane permeability increased. Cell-cycle analysis showed a slight but significant arrest at the G1 phase of cell cycle for LE. Both GE and LE reduced Hep-G2 viability independently; however, the combinations of both extracts were found to have an antagonistic effect on cell viability and increased cultured Hep-G2 survival.

  7. Toxicity Effect of Silver Nanoparticles on Mice Liver Primary Cell Culture and HepG2 Cell Line

    Science.gov (United States)

    Faedmaleki, Firouz; H Shirazi, Farshad; Salarian, Amir-Ahmad; Ahmadi Ashtiani, Hamidreza; Rastegar, Hossein

    2014-01-01

    Nano-silver (AgNP) has biological properties which are significant for consumer products, food technology, textiles and medical applications (e.g. wound care products, implantable medical devices, in diagnosis, drug delivery, and imaging). For their antibacterial activity, silver nanoparticles are largely used in various commercially available products. Thus, the use of nano-silver is becoming more and more widespread in medicine. In this study we investigated the cytotoxic effects of AgNPs on liver primary cells of mice, as well as the human liver HepG2 cell. Cell viability was examined with MTT assay after HepG2 cells exposure to AgNPs at 1, 2, 3, 4, 5, 7.5, 10 ppm compared to mice primary liver cells at 1, 10, 50, 100, 150, 200, 400 ppm for 24h. AgNPs caused a concentration-dependent decrease of cell viability in both cells. IC50 value of 2.764 ppm (µg/mL) was calculated in HepG2 cell line and IC50 value of 121.7 ppm (µg/mL) was calculated in primary liver cells of mice. The results of this experiment indicated that silver nanoparticles had cytotoxic effects on HepG2 cell line and primary liver cells of mice. The results illustrated that nano-silver had 44 times stronger inhibitory effect on the growth of cancerous cells (HepG2 cell line) compared to the normal cells (primary liver cells of mice). which might further justify AgNPs as a cytotoxic agents and a potential anticancer candidate which needs further studies in this regard. PMID:24734076

  8. Galactosylated poly(ε-caprolactone) membrane promoted liver-specific functions of HepG2 cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yan, E-mail: zhang_yan@ecust.edu.cn [The Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Zhang, Yi [The Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Chen, Min; Zhou, Yan [The State Key Laboratory of Bioreactor Engineering, School of Bioengineering, East China University of Science and Technology, Shanghai, 200237 (China); Lang, Meidong, E-mail: mdlang@ecust.edu.cn [The Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China)

    2014-08-01

    The lack of pendant functional groups on the PCL backbone has been a great challenge for surface bioactivation of poly(ε-caprolactone) (PCL). In the present study, covalently galactosylated PCL (GPCL) was developed through coupling between the amino-functionalized PCL (NPCL) and the lactobionic acid (LA) and its potential application in maintenance of physiological functions of HepG2 cells was further evaluated. The structure and properties of GPCL were explored by {sup 1}H NMR, FT-IR, GPC and DSC. Moreover, the incorporation of galactose ligands onto GPCL membranes not only promoted higher wettability, but also radically changed surface morphology in comparison with PCL and NPCL according to the contact angle measurement and atomic force microscopy. When HepG2 cells were seeded onto these membranes, the cells on GPCL membranes showed more pronounced cell adhesion and tended to form aggregates during the initial adhesion stage and then progressively grew into multi-layer structures compared to those without galactose ligands by the observation with fluorescence microscope and scanning electron microscopy. Furthermore, live–dead assay and functional tests demonstrated that HepG2 cells on GPCL membranes had superior viability and maintained better liver-specific functions. Collectively, GPCL has great potential for hepatic tissue engineering scaffolds. - Graphical abstract: The specific recognition between the galactose ligands on the galactosylated poly(ε-caprolactone) membrane and the ASGPR on the HepG2 cell surface. The galactosylated poly(ε-caprolactone) membranes improved the cell-matrix interaction. The galactosylated functionalized PCL scaffold is a potential candidate for liver tissue engineering. - Highlights: • The specific recognition between the galactose ligands on the galactosylated poly(ε-caprolactone) membrane and the ASGPR on the HepG2 cell surface. • The galactosylated poly(ε-caprolactone) membranes improved the cell-matrix interaction. • The galactosylated functionalized PCL scaffold is a potential candidate for liver tissue engineering.

  9. Dihydrotestosterone regulating apolipoprotein M expression mediates via protein kinase C in HepG2 cells

    Directory of Open Access Journals (Sweden)

    Yi-zhou Ye

    2012-12-01

    Full Text Available Abstract Background Administration of androgens decreases plasma concentrations of high-density lipid cholesterol (HDL-C. However, the mechanisms by which androgens mediate lipid metabolism remain unknown. This present study used HepG2 cell cultures and ovariectomized C57BL/6 J mice to determine whether apolipoprotein M (ApoM, a constituent of HDL, was affected by dihydrotestosterone (DHT. Methods HepG2 cells were cultured in the presence of either DHT, agonist of protein kinase C (PKC, phorbol-12-myristate-13-acetate (PMA, blocker of androgen receptor flutamide together with different concentrations of DHT, or DHT together with staurosporine at different concentrations for 24 hrs. Ovariectomized C57BL/6 J mice were treated with DHT or vehicle for 7d or 14d and the levels of plasma ApoM and livers ApoM mRNA were measured. The mRNA levels of ApoM, ApoAI were determined by real-time RT-PCR. ApoM and ApoAI were determined by western blotting analysis. Results Addition of DHT to cell culture medium selectively down-regulated ApoM mRNA expression and ApoM secretion in a dose-dependent manner. At 10 nM DHT, the ApoM mRNA levels were about 20% lower than in untreated cells and about 40% lower at 1000 nM DHT than in the control cells. The secretion of ApoM into the medium was reduced to a similar extent. The inhibitory effect of DHT on ApoM secretion was not blocked by the classical androgen receptor blocker flutamide but by an antagonist of PKC, Staurosporine. Agonist of PKC, PMA, also reduced ApoM. At 0.5 μM PMA, the ApoM mRNA levels and the secretion of ApoM into the medium were about 30% lower than in the control cells. The mRNA expression levels and secretion of another HDL-associated apolipoprotein AI (ApoAI were not affected by DHT. The levels of plasma ApoM and liver ApoM mRNA of DHT-treated C57BL/6 J mice were lower than those of vehicle-treated mice. Conclusions DHT directly and selectively down-regulated the level of ApoM mRNA and the secretion of ApoM by protein kinase C but independently of the classical androgen receptor.

  10. Low-dose hyper-radiosensitivity in human hepatocellular HepG2 cells is associated with Cdc25C-mediated G2/M cell cycle checkpoint control.

    Science.gov (United States)

    Xue, Jun; Zong, Yan; Li, Pin-Dong; Wang, Li-Xia; Li, Yun-Qiao; Niu, Yan-Feng

    2016-10-01

    Although the significance of cell cycle checkpoints in overcoming low-dose hyper-radiosensitivity (HRS) has been proposed, the underlying mechanism of HRS in human hepatocellular cells remains unclear. Therefore, the aim of this study was to characterize HRS inhuman hepatocellular HepG2 cells and to explore the molecular mechanism(s) mediating this response. HepG2 cells were exposed to various single doses of γ radiation (from 0 Gy to 4 Gy), and then were assayed at subsequent time-points. Survival curves were then generated using a linear-quadratic (LQ) equation and a modified induced repair model (MIRM). The percentage of cells in the G1, G2/M, and S phases of the cell cycle were also examined using propidium iodide (PI) staining and flow cytometry. Levels of total cell division cyclin 25C (Cdc25C) and phosphorylated Cdc25C were examined by Western blotting. Low-dose γ radiation (cells, while doses of 0.3, 0.5, and 2.0 Gy γ radiation significantly arrested HepG2 cells in the G2/M phase. While total Cdc25C levels remained unchanged after irradiation, levels of phosphorylated Cdc25C markedly increased 6, 16, and 24 h after treatment with 0.5 or 2.0 Gy radiation, and they peaked after 16 h. The latter observation is consistent with the G2/M arrest that was detected following irradiation. These findings indicate that low-dose HRS in HepG2 cells may be associated with Cdc25C-mediated G2/M cell cycle checkpoint control.

  11. Development and validation of a high-content screening in vitro micronucleus assay in CHO-k1 and HepG2 cells

    NARCIS (Netherlands)

    Westerink, W.M.; Schirris, T.J.J.; Horbach, G.J.; Schoonen, W.G.

    2011-01-01

    In the present study an automated image analysis assisted in vitro micronucleus assay was developed with the rodent cell line CHO-k1 and the human hepatoma cell line HepG2, which are both commonly used in regulatory genotoxicity assays. The HepG2 cell line was chosen because of the presence in these

  12. Genotoxic potential of the perfluorinated chemicals PFOA, PFOS, PFBS, PFNA and PFHxA in human HepG2 cells

    DEFF Research Database (Denmark)

    Eriksen, Kirsten Thorup; Raaschou-Nielsen, Ole; Sørensen, Mette

    2010-01-01

    Synthetically produced perfluorinated chemicals (PFCs) are widely used in industrial products because of their anti-wetting and surfactant properties. PFCs are suspected carcinogens and a possible mechanism of action is generation of oxidative stress. We have investigated the potential of five...... different PFCs to generate reactive oxygen species (ROS) and to induce oxidative DNA damage in HepG2 cells. Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) increased the intracellular ROS production by 1.52-fold (95% CI, 1.37-1.67) and 1.25-fold (95% CI, 1.10-1.40), respectively. However......, the increase in ROS production was not concentration-dependent and the compounds did not generate DNA damage that could be detected by the alkaline comet assay as strand breakage and alkali-labile sites or formamidopyrimidine-DNA-glycosylase (FPG) sites. Perfluorobutane sulfonate (PFBS) and perfluorohexanoic...

  13. Ku70 acetylation and modulation of c-Myc/ATF4/CHOP signaling axis by SIRT1 inhibition lead to sensitization of HepG2 cells to TRAIL through induction of DR5 and down-regulation of c-FLIP

    DEFF Research Database (Denmark)

    Kim, Mi-Ju; Hong, Kyung-Soo; Kim, Hak-Bong

    2013-01-01

    In this study, we investigated the role of c-Myc/ATF4/CHOP signaling pathway in sensitization of human hepatoma HepG2 cells to TRAIL. Knockdown of SIRT1 or treatment with SIRT1 inhibitor caused the up-regulation of DR5 and down-regulation of c-FLIP through modulation of c-Myc/ATF4/CHOP pathway, a...

  14. MnSOD upregulation induces autophagic programmed cell death in senescent keratinocytes.

    Directory of Open Access Journals (Sweden)

    Emeric Deruy

    Full Text Available Senescence is a state of growth arrest resulting mainly from telomere attrition and oxidative stress. It ultimately leads to cell death. We have previously shown that, in keratinocytes, senescence is induced by NF-kappaB activation, MnSOD upregulation and H(2O(2 overproduction. We have also shown that senescent keratinocytes do not die by apoptosis but as a result of high macroautophagic activity that targets the primary vital cell components. Here, we investigated the mechanisms that activate this autophagic cell death program. We show that corpses occurring at the senescence plateau display oxidatively-damaged mitochondria and nucleus that colocalize with autophagic vacuoles. The occurrence of such corpses was decreased by specifically reducing the H(2O(2 level with catalase, and, conversely, reproduced by overexpressing MnSOD or applying subtoxic doses of H(2O(2. This H(2O(2-induced cell death did occur through autophagy since it was accompanied by an accumulation of autophagic vesicles as evidenced by Lysotracker staining, LC3 vesiculation and transmission electron microscopy. Most importantly, it was partly abolished by 3-methyladenine, the specific inhibitor of autophagosome formation, and by anti-Atg5 siRNAs. Taken together these results suggest that autophagic cell death is activated in senescent keratinocytes because of the upregulation of MnSOD and the resulting accumulation of oxidative damages to nucleus and mitochondria.

  15. Triptolide induces apoptosis through the SERCA 3 upregulation in PC12 cells.

    Science.gov (United States)

    Krizanova, Olga; Markova, Jana; Pacak, Karel; Skultety, Ludovit; Soltysova, Andrea; Hudecova, Sona

    2014-01-01

    Diterpenoid triepoxide - Triptolide (TTL) - increased protein levels of the noradrenaline transporter in three pheochromocytoma cell lines. This transporter is involved in the apoptosis induction through the inhibition of a transcription factor NF-kappa B. Nevertheless, calcium release from the endoplasmic reticulum can also induce inner mitochondrial pathway of apoptosis in variety of cells. Therefore, the aim of this work was to evaluate an involvement of calcium and, more specifically, the intracellular calcium transport systems in the apoptosis induction in pheochrocytoma cell line PC12. We observed significantly increased amount of reticular calcium in TTL-treated cells compared to control, untreated cells. Surprisingly, gene expression of the IP3 receptors was not changed after the TTL treatment, but ryanodine receptor of the type 2 (RyR2) was downregulated and sarco/endoplasmic reticulum calcium ATPase type 3 (SERCA 3) was upregulated in TTL- treated cells, compared to untreated controls. SERCA 3 blocking with the specific blocker thapsigargin prevented increase in apoptosis observed by the TTL treatment. Decrease in the ATP production by a replacement of glucose in the cultivation medium for its nonutilizable analog 2-deoxyglucose also prevented induction of the apoptosis in TTL-treated PC12 cells. Thus, these results suggest that upregulation of the SERCA 3 is ultimately involved in the TTL-induced apoptosis in PC12 cells.

  16. Induction of heme oxygenase-1 inhibits cell death in crotonaldehyde-stimulated HepG2 cells via the PKC-δ-p38-Nrf2 pathway.

    Directory of Open Access Journals (Sweden)

    Seung Eun Lee

    Full Text Available BACKGROUND: Crotonaldehyde, an alpha, beta-unsaturated aldehyde present in cigarette smoke, is an environmental pollutant and a product of lipid peroxidation. It also produces adverse effects to humans and is considered as a risk factor for various diseases. Heme oxygenase-1 (HO-1 plays important roles in protecting cells against oxidative stress as a prime cellular defense mechanism. However, HO-1 may be associated with cell proliferation and resistance to apoptosis in cancer cells. The aim of this study was to examine the effects of HO-1 induction on cell survival in crotonaldehyde-stimulated human hepatocellular carcinoma (HepG2 cells. METHODS: To investigate the signaling pathway involved in crotonaldehyde-induced HO-1 expression, we compared levels of inhibition efficiency of specific inhibitors and specific small interfering RNAs (siRNAs of several kinases. The cell-cycle and cell death was measured by FACS and terminal dUTP nick-end labeling (TUNEL staining. RESULTS: Treatment with crotonaldehyde caused a significant increase in nuclear translocation of NF-E2 related factor (Nrf2. Treatment with inhibitors of the protein kinase C-δ (PKC-δ and p38 pathways resulted in obvious blockage of crotonaldehyde-induced HO-1 expression. Furthermore, treatment with HO-1 siRNA and the specific HO-1 inhibitor zinc-protoporphyrin produced an increase in the G(0/G(1 phase of the cell cycle in crotonaldehyde-stimulated HepG2 cells. CONCLUSIONS: Taken together, the results support an anti-apoptotic role for HO-1 in crotonaldehyde-stimulated human hepatocellular carcinoma cells and provide a mechanism by which induction of HO-1 expression via PKC-δ-p38 MAPK-Nrf2 pathway may promote tumor resistance to oxidative stress.

  17. Genotoxic potential of montmorillonite clay mineral and alteration in the expression of genes involved in toxicity mechanisms in the human hepatoma cell line HepG2

    Energy Technology Data Exchange (ETDEWEB)

    Maisanaba, Sara, E-mail: saramh@us.es [Area of Toxicology, Faculty of Pharmacy, University of Sevilla, Profesor García González no. 2, 41012 Seville (Spain); Hercog, Klara; Filipic, Metka [National Institute of Biology, Department for Genetic Toxicology and Cancer Biology, Vecna pot 111, 1000 Ljubljana (Slovenia); Jos, Ángeles [Area of Toxicology, Faculty of Pharmacy, University of Sevilla, Profesor García González no. 2, 41012 Seville (Spain); Zegura, Bojana [National Institute of Biology, Department for Genetic Toxicology and Cancer Biology, Vecna pot 111, 1000 Ljubljana (Slovenia)

    2016-03-05

    Highlights: • Cloisite{sup ®}Na{sup +} has a wide range of well-documented and novel applications. • Cloisite{sup ®}Na{sup +} induces micronucleus, but not nuclear bridges or nuclear buds in HepG2 cells. • Cloisite{sup ®}Na{sup +} induces changes in the gene expression. • Gene alteration is presented mainly after 24 h of exposure to Cloisite{sup ®}Na{sup +}. - Abstract: Montmorillonite, also known as Cloisite{sup ®}Na{sup +} (CNa{sup +}), is a natural clay with a wide range of well-documented and novel applications, such as pharmaceutical products or food packaging. Although considered a low toxic product, the expected increased exposure to CNa{sup +} arises concern on the potential consequences on human and environmental health especially as its genotoxicity has scarcely been investigated so far. Thus, we investigated, for the first time, the influence of non-cytotoxic concentrations of CNa{sup +} (15.65, 31.25 and 62.5 μg/mL) on genomic instability of human hepatoma cell line (HepG2) by determining the formation of micronuclei (MNi), nucleoplasmic bridges (NPBs) and nuclear buds (NBUDs) with the Cytokinesis block micronucleus cytome assay. Further on we studied the influence of CNa{sup +} on the expression of several genes involved in toxicity mechanisms using the real-time quantitative PCR. The results showed that CNa{sup +} increased the number of MNi, while the numbers of NBUDs and NPBs were not affected. In addition it deregulated genes in all the groups studied, mainly after longer time of exposure. These findings provide the evidence that CNa{sup +} is potentially genotoxic. Therefore further studies that will elucidate the molecular mechanisms involved in toxic activity of CNa{sup +} are needed for hazard identification and human safety assessment.

  18. Proapoptotic activity of aflatoxin B1 and sterigmatocystin in HepG2 cells

    Directory of Open Access Journals (Sweden)

    Yang Liu

    2014-01-01

    Full Text Available Aflatoxin B1 (AFB1 and sterigmatocystin (ST are two hepatocarcinogenic mycotoxins that are commonly coexisted in cereal grains, and their co-proapoptotic activity in HepG2 cells was studied. The values of IC50, which is the dosage of mycotoxin resulting in a 50% cell growth inhibition measured by a sulforhodamine B (SRB colorimetric assay, were 16.9 μM and 7.3 μM for AFB1 and ST, respectively. Additively and dose-dependently, cell apoptosis-related toxicity endpoints of double strand DNA and ATP content were decreased while the intracellular ROS and mitochondria membrane permeability (MMP were increased. Consistently, when cell cycle is arrest at G0/G1 or S phase by AFB1 and/or ST, the experimental results from flow cytometry assay demonstrated that the rate of cell apoptosis and mitochondrial membrane potential were also additively increased and decreased, respectively, in a dose-dependent manner. Thus, the integrity of mitochondria (MMP and membrane potential that is the central component of cell apoptosis is disrupted by AFB1 and ST in an additive manner. With the immunocytochemistry analysis showing increased expression of apoptosis-related proteins of Bax, Caspase-3 and p53 and decreased expression of Bcl-2 protein, an additive nature of the co-proapoptotic activity of AFB1 and ST was revealed.

  19. Proapoptotic activity of aflatoxin B1 and sterigmatocystin in HepG2 cells.

    Science.gov (United States)

    Liu, Yang; Du, Ming; Zhang, Genyi

    2014-01-01

    Aflatoxin B1 (AFB1) and sterigmatocystin (ST) are two hepatocarcinogenic mycotoxins that are commonly coexisted in cereal grains, and their co-proapoptotic activity in HepG2 cells was studied. The values of IC50, which is the dosage of mycotoxin resulting in a 50% cell growth inhibition measured by a sulforhodamine B (SRB) colorimetric assay, were 16.9 μM and 7.3 μM for AFB1 and ST, respectively. Additively and dose-dependently, cell apoptosis-related toxicity endpoints of double strand DNA and ATP content were decreased while the intracellular ROS and mitochondria membrane permeability (MMP) were increased. Consistently, when cell cycle is arrest at G0/G1 or S phase by AFB1 and/or ST, the experimental results from flow cytometry assay demonstrated that the rate of cell apoptosis and mitochondrial membrane potential were also additively increased and decreased, respectively, in a dose-dependent manner. Thus, the integrity of mitochondria (MMP and membrane potential) that is the central component of cell apoptosis is disrupted by AFB1 and ST in an additive manner. With the immunocytochemistry analysis showing increased expression of apoptosis-related proteins of Bax, Caspase-3 and p53 and decreased expression of Bcl-2 protein, an additive nature of the co-proapoptotic activity of AFB1 and ST was revealed.

  20. Evaluation of anti-hepatocarcinoma capacity of puerarin nanosuspensions against human HepG2 cells

    Science.gov (United States)

    Meng, Xiang-Ping; Zhang, Zhen; Wang, Yi-Fei; Wang, Zhi-ping; Chen, Tong-sheng

    2017-02-01

    Hepatocarcinoma, a malignant cancer, threaten human life badly. It is a current issue to seek the effective natural remedy from plant to treat cancer due to the resistance of the advanced hepatocarcinoma to chemotherapy. Puerarin (Pue), a major active ingredient in the traditional Chinese medicine Gegen, has a wide range of pharmacological properties and is considered to have anti-hepatocarcinoma effects. However its low oral bioavailability restricts its wide application. In this report, Pue nanosuspension (Pue-NS) composed of Pue and poloxamer 188 was prepared by high pressure homogenization technique. The in vitro anti-hepatocarcinoma effects of Pue-NS relative to efficacy of bulk Pue were evaluated. The particle size and zeta potential of Pue-NS were 218.5 nm and -18.8 mV, respectively. MTT assay showed that Pue-NS effectively inhibited the proliferation of HepG2 cells, and the corresponding IC50 values of Pue-NS and bulk Pue were 3.39 and 5.73 μg/ml. These results suggest that the delivery of Pue-NS is a promising approach for treating tumors.

  1. Does Resveratrol Improve Insulin Signalling in HepG2 Cells?

    Science.gov (United States)

    Norouzzadeh, Marjan; Amiri, Fatemehsadat; Saboor-Yaraghi, Ali Akbar; Shemirani, Farnoosh; Kalikias, Yas; Sharifi, Loghman; Seyyedsalehi, Monireh Sadat; Mahmoudi, Maryam

    2017-04-01

    Diabetes mellitus is a common metabolic disorder with high global prevalence. It is characterized by a decrease in insulin secretion or a decrease in insulin sensitivity or both. The aim of the present study was to investigate the effects of resveratrol treatment on the expression of the genes involved in insulin signalling cascade, such as Forkhead box protein O1 (FoxO1), 3-phosphoinositide-dependent protein kinase 1 (PDPK1) and mammalian target of rapamycin (mTOR). HepG2 cells were cultured in serum-free medium with high concentrations of glucose and insulin and then were treated with resveratrol (5, 10 and 20 µM) for 24 and 48 hours. Complementary deoxyribonucleic acids (cDNAs) were synthesized followed by RNA extraction. Real-time quantitative reverse transcription polymerase chain reaction was used to analyze the expression of FoxO1, PDPK1 and mTOR. Resveratrol increased the expression of PDPK1, mTOR and FoxO1. No significant difference was seen among differing dosages of resveratrol, but treatments for 48 hours exerted the greatest effectiveness. Our results were consistent with other studies showing the beneficial effects of resveratrol on diabetes. However, considering the effects of resveratrol in increasing FoxO1 and gluconeogenic gene expression, long-term usage of resveratrol should be investigated in greater depth in future studies. Copyright © 2016 Canadian Diabetes Association. Published by Elsevier Inc. All rights reserved.

  2. Surface ligand dependent toxicity of zinc oxide nanoparticles in HepG2 cell model

    Science.gov (United States)

    Bartczak, D.; Baradez, M.-O.; Merson, S.; Goenaga-Infante, H.; Marshall, D.

    2013-04-01

    Physicochemical properties of nanoparticles (NP) strongly affect their influence on cell behaviour, but can be significantly distorted by interactions with the proteins present in biological solutions. In this study we show how different surface functionalities of zinc oxide (ZnO) NP lead to changes in the size distribution and dissolution of the NP in serum containing cell culture media and how this impacts on NP toxicity. NPs capped with weakly bound large proteins undergo substantial transformations due to the exchange of the original surface ligands to the components of the cell culture media. Conversely, NP capped with a tight monolayer of small organic molecules or with covalently conjugated proteins show significantly higher stability. These differences in ligand exchange also affect the toxicity of the NP to the HepG2 liver cell model, with the NP capped with small organic molecules being more toxic than those capped with large proteins. This study highlights the importance of characterising NPs in biological media and the effect the media has during in-vitro analysis.

  3. Terpenoids from Curcuma wenyujin increased glucose consumption on HepG2 cells.

    Science.gov (United States)

    Zhou, Chang-Xin; Zhang, Li-Sha; Chen, Fei-Fei; Wu, Hao-Shu; Mo, Jian-Xia; Gan, Li-She

    2017-09-01

    Thirty four terpenoids, including two new cadinane-type sesquiterpenoids containing conjugated aromatic-ketone moieties, curcujinone A (1) and curcujinone B (2), were isolated from 95% ethanol extract of the root tubers of Curcuma wenyujin. Their structures were determined by spectroscopic methods, especially 2D NMR and HRMS techniques. The relative and absolute configurations of 1 and 2 were identified by quantum chemical DFT and TDDFT calculations of the 13 C NMR chemical shifts, ECD spectra, and specific optical rotations. All compounds and extracts were evaluated for their anti-diabetic activities with a glucose consumption model on HepG2 Cells. The petroleum fraction CWP (10μg/mL) and compounds curcumenol (4), 7α,11α-epoxy-5β-hydroxy-9-guaiaen-8-one (5), curdione (17), (1S, 4S, 5S 10S)-germacrone (18), zederone (20), a mixture of curcumanolide A (25) and curcumanolide B (26), gajutsulactone B (27), and wenyujinin C (30) showed promising activities with over 45% increasing of glucose consumption at 10μM. Copyright © 2017. Published by Elsevier B.V.

  4. The color and size of chili peppers (Capsicum annuum) influence Hep-G2 cell growth.

    Science.gov (United States)

    Popovich, David G; Sia, Sharon Y; Zhang, Wei; Lim, Mon L

    2014-11-01

    Four types of chili (Capsicum annuum) extracts, categorized according to color; green and red, and size; small and large were studied in Hep-G2 cells. Red small (RS) chili had an LC50 value of 0.378 ± 0.029 compared to green big (GB) 1.034 ± 0.061 and green small (GS) 1.070 ± 0.21 mg/mL. Red big (RB) was not cytotoxic. Capsaicin content was highest in RS and produced a greater percentage sub-G1 cells (6.47 ± 1.8%) after 24 h compared to GS (2.96 ± 1.3%) and control (1.29 ± 0.8%) cells. G2/M phase was reduced by GS compared to RS and control cells. RS at the LC50 concentration contained 1.6 times the amount of pure capsaicin LC50 to achieve the same effect of capsaicin alone. GS and GB capsaicin content at the LC50 value was lower (0.2 and 0.66, respectively) compared to the amount of capsaicin to achieve a similar reduction in cell growth.

  5. Species-specific differences in peroxisome proliferation, catalase, and SOD2 upregulation as well as toxicity in human, mouse, and rat hepatoma cells induced by the explosive and environmental pollutant 2,4,6-trinitrotoluene.

    Science.gov (United States)

    Naumenko, Ekaterina Anatolevna; Ahlemeyer, Barbara; Baumgart-Vogt, Eveline

    2017-03-01

    2,4,6-Trinitrotoluene (TNT) has been widely used as an explosive substance and its toxicity is still of interest as it persisted in polluted areas. TNT is metabolized in hepatocytes which are prone to its toxicity. Since analysis of the human liver or hepatocytes is restricted due to ethical reasons, we investigated the effects of TNT on cell viability, reactive oxygen species (ROS) production, peroxisome proliferation, and antioxidative enzymes in human (HepG2), mouse (Hepa 1-6), and rat (H4IIEC3) hepatoma cell lines. Under control conditions, hepatoma cells of all three species were highly comparable exhibiting identical proliferation rates and distribution of their cell cycle phases. However, we found strong differences in TNT toxicity with the lowest IC50 values (highest cell death rate) for rat cells, whereas human and mouse cells were three to sevenfold less sensitive. Moreover, a strong decrease in cellular dehydrogenase activity (MTT assay) and increased ROS levels were noted. TNT caused peroxisome proliferation with rat hepatoma cells being most responsive followed by those from mouse and human. Under control conditions, rat cells contained fivefold higher peroxisomal catalase and mitochondrial SOD2 activities and a twofold higher capacity to reduce MTT than human and mouse cells. TNT treatment caused an increase in catalase and SOD2 mRNA and protein levels in human and mouse, but not in rat cells. Similarly, human and mouse cells upregulated SOD2 activity, whereas rat cells failed therein. We conclude that TNT induced oxidative stress, peroxisome proliferation and mitochondrial damage which are highest in rat cells rendering them most susceptible toward TNT. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 989-1006, 2017. © 2016 Wiley Periodicals, Inc.

  6. Abrogation of radiation-inducible telomerase upregulation in HPV16 E6 transfectants of human lymphoblasts

    Energy Technology Data Exchange (ETDEWEB)

    Neuhof, D.; Auberger, F.; Ruess, A.; Weber, K.J. [Radiobiology Research Lab., Dept. of Clinical Radiology, Univ. of Heidelberg (Germany); Wenz, F. [Section for Radiation Oncology, Univ. Clinic Mannheim (Germany)

    2004-01-01

    Background: telomerase activity in a human lymphoblastoid cell line with wild-type p53 status (TK6) was previously shown to be rapidly induced by ionizing radiation doses as low as 10 cgy. Since this low-dose response was absent in a closely related cell line overexpressing a mutant form of p53 (WTK1), the putative involvement of p53 was further investigated using stable human papillomavirus 16 (HPV16) E6 transfectants of these cell lines. The E6 product mediates rapid degradation of wild-type p53, but has also been found to upregulate telomerase. Material and methods: telomerase activity in HPV16 E6 transfectants of the human lymphoblastoid cell lines TK6 and WTK1 was measured by PCR/ELISA and was quantified using internal standards (titration by cell number) run within each separate assay. Mean telomere length was determined by southern hybridization of terminal restriction fragments with a biotin-labeled telomeric DNA probe. Results: the TK6E6 and the WTK1E6 cells exhibited higher baseline telomerase activities than the parental cells. This was also accompanied by increased telomere lengths. Radiation exposure (up to 10 gy) was unable to significantly further enhance telomerase activities, although the dynamic range of the assay would have allowed to record higher signals. Conclusion: the lacking radiation induction of telomerase activities in the E6 transfectants could reflect saturation, if E6 and radiation would share a common pathway of telomerase upregulation. Present evidence from the literature, however, suggests that E6 mediates telomerase reverse transcriptase (TERT) subunit transcriptional activation, whereas radiation signals to posttranscriptional/posttranslational control of telomerase activity. Therefore, the present data enforce the previous hypothesis of a p53 dependence of telomerase upregulation by low doses of radiation and its abrogation, likely due to p53 degradation, in E6-expressing cells. (orig.)

  7. Intestinal upregulation of melanin-concentrating hormone in TNBS-induced enterocolitis in adult zebrafish.

    Directory of Open Access Journals (Sweden)

    Brenda M Geiger

    Full Text Available BACKGROUND: Melanin-concentrating hormone (MCH, an evolutionarily conserved appetite-regulating neuropeptide, has been recently implicated in the pathogenesis of inflammatory bowel disease (IBD. Expression of MCH is upregulated in inflamed intestinal mucosa in humans with colitis and MCH-deficient mice treated with trinitrobenzene-sulfonic acid (TNBS develop an attenuated form of colitis compared to wild type animals. Zebrafish have emerged as a new animal model of IBD, although the majority of the reported studies concern zebrafish larvae. Regulation MCH expression in the adult zebrafish intestine remains unknown. METHODS: In the present study we induced enterocolitis in adult zebrafish by intrarectal administration of TNBS. Follow-up included survival analysis, histological assessment of changes in intestinal architecture, and assessment of intestinal infiltration by myeloperoxidase positive cells and cytokine transcript levels. RESULTS: Treatment with TNBS dose-dependently reduced fish survival. This response required the presence of an intact microbiome, since fish pre-treated with vancomycin developed less severe enterocolitis. At 6 hours post-challenge, we detected a significant influx of myeloperoxidase positive cells in the intestine and upregulation of both proinflammatory and anti-inflammatory cytokines. Most importantly, and in analogy to human IBD and TNBS-induced mouse experimental colitis, we found increased intestinal expression of MCH and its receptor in TNBS-treated zebrafish. CONCLUSIONS: Taken together these findings not only establish a model of chemically-induced experimental enterocolitis in adult zebrafish, but point to effects of MCH in intestinal inflammation that are conserved across species.

  8. Mycophenolic acid induces ATP-binding cassette transporter A1 (ABCA1) expression through the PPAR{gamma}-LXR{alpha}-ABCA1 pathway

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yanni; Lai, Fangfang; Xu, Yang; Wu, Yexiang; Liu, Qi; Li, Ni; Wei, Yuzhen; Feng, Tingting; Zheng, Zhihui; Jiang, Wei; Yu, Liyan; Hong, Bin [Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050 (China); Si, Shuyi, E-mail: sisyimb@hotmail.com [Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050 (China)

    2011-11-04

    Highlights: Black-Right-Pointing-Pointer Using an ABCA1p-LUC HepG2 cell line, we found that MPA upregulated ABCA1 expression. Black-Right-Pointing-Pointer MPA induced ABCA1 and LXR{alpha} protein expression in HepG2 cells. Black-Right-Pointing-Pointer PPAR{gamma} antagonist GW9662 markedly inhibited MPA-induced ABCA1 and LXR{alpha} protein expression. Black-Right-Pointing-Pointer The effect of MPA upregulating ABCA1 was due mainly to activation of the PPAR{gamma}-LXR{alpha}-ABCA1 pathway. -- Abstract: ATP-binding cassette transporter A1 (ABCA1) promotes cholesterol and phospholipid efflux from cells to lipid-poor apolipoprotein A-I and plays an important role in atherosclerosis. In a previous study, we developed a high-throughput screening method using an ABCA1p-LUC HepG2 cell line to find upregulators of ABCA1. Using this method in the present study, we found that mycophenolic acid (MPA) upregulated ABCA1 expression (EC50 = 0.09 {mu}M). MPA upregulation of ABCA1 expression was confirmed by real-time quantitative reverse transcription-PCR and Western blot analysis in HepG2 cells. Previous work has indicated that MPA is a potent agonist of peroxisome proliferator-activated receptor gamma (PPAR{gamma}; EC50 = 5.2-9.3 {mu}M). Liver X receptor {alpha} (LXR{alpha}) is a target gene of PPAR{gamma} and may directly regulate ABCA1 expression. Western blot analysis showed that MPA induced LXR{alpha} protein expression in HepG2 cells. Addition of PPAR{gamma} antagonist GW9662 markedly inhibited MPA-induced ABCA1 and LXR{alpha} protein expression. These data suggest that MPA increased ABCA1 expression mainly through activation of PPAR{gamma}. Thus, the effects of MPA on upregulation of ABCA1 expression were due mainly to activation of the PPAR{gamma}-LXR{alpha}-ABCA1 signaling pathway. This is the first report that the antiatherosclerosis activity of MPA is due to this mechanism.

  9. p53 inhibits the upregulation of sirtuin 1 expression induced by c-Myc.

    Science.gov (United States)

    Yuan, Fang; Liu, Lu; Lei, Yonghong; Tang, Peifu

    2017-10-01

    Sirtuin 1 (Sirt1), a conserved NAD(+) dependent deacetylase, is a mediator of life span by calorie restriction. However, Sirt1 may paradoxically increase the risk of cancer. Accordingly, the expression level of Sirt1 is selectively elevated in numerous types of cancer cell; however, the mechanisms underlying the differential regulation remain largely unknown. The present study demonstrated that oncoprotein c-Myc was a direct regulator of Sirt1, which accounts for the upregulation of Sirt1 expression only in the cells without functional p53. In p53 deficient cells, the overexpression of c-Myc increased Sirt1 mRNA and protein expression levels as well as its promoter activity, whereas the inhibitor of c-Myc, 10058-F4, induced decreased Sirt1 basal mRNA and protein expression levels. Deletion/mutation mapping analyses revealed that c-Myc bound to the conserved E-box[-189 to -183 base pair (bp)] of the Sirt1 promoter. In addition, p53 and c-Myc shared at least response element and the presence of p53 may block the binding of c-Myc to the Sirt1 promoter, thus inhibit the c-Myc mediated upregulation of Sirt1 promoter activity. The present study indicated that the expression level of Sirt1 was tightly regulated by oncoprotein c-Myc and tumor suppressor p53, which aids an improved understanding of its expression regulation and tumor promoter role in certain conditions.

  10. Retinoic acid induces HL-60 cell differentiation via the upregulation of miR-663

    Directory of Open Access Journals (Sweden)

    Zhuan Zhou

    2011-04-01

    Full Text Available Abstract Background Differentiation of the acute myeloid leukemia (AML cell line HL-60 can be induced by all trans-retinoic acid (ATRA; however, the mechanism regulating this process has not been fully characterized. Methods Using bioinformatics and in vitro experiments, we identified the microRNA gene expression profile of HL-60 cells during ATRA induced granulocytic differentiation. Results Six microRNAs were upregulated by ATRA treatment, miR-663, miR-494, miR-145, miR-22, miR-363* and miR-223; and three microRNAs were downregulated, miR-10a, miR-181 and miR-612. Additionally, miR-663 expression was regulated by ATRA. We used a lentivirus (LV backbone incorporating the spleen focus forming virus (SFFV-F promoter to drive miR-663 expression, as the CMV (Cytomegalovirus promoter is ineffective in some lymphocyte cells. Transfection of LV-miR-663 induced significant HL-60 cell differentiation in vitro. Conclusions Our results show miR-663 may play an important role in ATRA induced HL-60 cell differentiation. Lentivirus delivery of miR-663 could potentially be used directly as an anticancer treatment in hematological malignancies

  11. Antisense oligonucleotide inhibition of hepatitis C virus genotype 4 replication in HepG2 cells

    Directory of Open Access Journals (Sweden)

    Omran Moataza H

    2006-06-01

    Full Text Available Abstract Background Hepatitis C (HCV viral infection is a serious medical problem in Egypt and it has a devastating impact on the Egyptian economy. It is estimated that over 15% of Egyptians are infected by the virus and thus finding a cure for this disease is of utmost importance. Current therapies for hepatitis C virus (HCV genotype 4 with interferon/ribavirin have not been successful and thus the development of alternative therapy for this genotype is disparately needed. Results Although previous studies utilizing viral subgenomic or full cDNA fragments linked to reporter genes transfected into adhered cells or in a cell free system showed promise, demonstration of efficient viral replication was lacking. Thus, we utilized HepG2 cells infected with native HCV RNA genomes in a replication competent system and used antisense phosphorothioate Oligonucleotides (S-ODN against stem loop IIId and the AUG translation start site of the viral polyprotein precursor to monitor viral replication. We were able to show complete arrest of intracellular replication of HCV-4 at 1 uM S-ODN, thus providing a proof of concept for the potential antiviral activity of S-ODN on native genomic replication of HCV genotype 4. Conclusion We have successfully demonstrated that by using two S-ODNs [(S-ODN1 (nt 326–348 and S-ODN-2 (nt 264–282], we were able to completely inhibit viral replication in culture, thus confirming earlier reports on subgenomic constructs and suggesting a potential therapeutic value in HCV type 4.

  12. 40 GHz RF biosensor based on microwave coplanar waveguide transmission line for cancer cells (HepG2) dielectric characterization.

    Science.gov (United States)

    Chen, Yu-Fu; Wu, Hung-Wei; Hong, Yong-Han; Lee, Hsin-Ying

    2014-11-15

    This paper presents a 40-GHz RF biosensor that involves using a microwave coplanar waveguide (CPW) transmission line for the dielectric characterization of cancer cells (Hepatoma G2, HepG2). In the past, conventional resonator-based biosensors were designed to operate at a specific resonant peak; however, the dielectric sensitivity of the cells was restricted to a narrow bandwidth. To provide a very wide bandwidth (1-40 GHz), biosensors were based on a microwave CPW transmission line. The proposed biosensor can rapidly measure two frequency-dependent cell-based dielectric parameters of HepG2 cells, microwave attenuation (α(f)cell) and the dielectric constant (εr(f)cell), while removing the microwave parasitic effects (including the cultured medium and substrate materials). The proposed biosensor can be applied in postoperative cancer diagnosis. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Fascaplysin sensitizes cells to TRAIL-induced apoptosis through upregulating DR5 expression

    Science.gov (United States)

    Wang, Feng; Chen, Haimin; Yan, Xiaojun; Zheng, Yanling

    2013-05-01

    This study investigated the molecular mechanism of anti-tumor effect of fascaplysin, a nitrogenous red pigment firstly isolated from a marine sponge. Microarray analysis show that the TNF and TNF receptor superfamily in human umbilical vein endothelial cells (HUVEC) and human hepatocarcinoma cells (BEL-7402) were significantly regulated by fascaplysin. Western Blot results reveal that fascaplysin increased the expression of cleaved caspase-9, active caspase-3, and decreased the level of procaspase-8 and Bid. Flow cytometry and cytotoxicity tests indicate that fascaplysin sensitized cells to tumor necrosis-related apoptosisinducing ligand-(TRAIL) induced apoptosis, which was markedly blocked by TRAIL R2/Fc chimera, a dominant negative form of TRAIL receptor DR5. Therefore, our results demonstrate that fascaplysin promotes apoptosis through the activation of TRAIL signaling pathway by upregulating DR5 expression.

  14. Lipopolysaccharide-induced pulpitis up-regulates TRPV1 in trigeminal ganglia.

    Science.gov (United States)

    Chung, M-K; Lee, J; Duraes, G; Ro, J Y

    2011-09-01

    Tooth pain often accompanies pulpitis. Accumulation of lipopolysaccharides (LPS), a product of Gram-negative bacteria, is associated with painful clinical symptoms. However, the mechanisms underlying LPS-induced tooth pain are not clearly understood. TRPV1 is a capsaicin- and heat-gated nociceptive ion channel implicated in thermosensation and hyperalgesia under inflammation or injury. Although TRPV1 is expressed in pulpal afferents, it is not known whether the application of LPS to teeth modulates TRPV1 in trigeminal nociceptors. By assessing the levels of protein and transcript of TRPV1 in mouse trigeminal ganglia, we demonstrate that dentinal application of LPS increases the expression of TRPV1. Our results suggest that the up-regulation of TRPV1 in trigeminal nociceptors following bacterial infection could contribute to hyperalgesia under pulpitis conditions.

  15. Hypocholesterolemic mechanism of phenolics-enriched extract from Moringa oleifera leaves in HepG2 cell lines

    OpenAIRE

    Peera Tabboon; Bungorn Sripanidkulchai; Kittisak Sripanidkulchai

    2016-01-01

    Previous studies have demonstrated the hypolipidemic activity of Moringa oleifera (MO) leaves via lowering serum levels of cholesterol, but the mechanism of action is unknown. In this study, we demonstrated the hypocholesterolemic mechanism of a phenolics-enriched extract of Moringa oleifera leaf (PMO) in HepG2 cells. When compared to the control treatment, PMO significantly decreased total intracellular cholesterol, inhibited the activity of HMG CoA reductase in a dosedependent m...

  16. Effects of short-chain chlorinated paraffins exposure on the viability and metabolism of human hepatoma HepG2 cells.

    Science.gov (United States)

    Geng, Ningbo; Zhang, Haijun; Zhang, Baoqin; Wu, Ping; Wang, Feidi; Yu, Zhengkun; Chen, Jiping

    2015-03-03

    Short-chain chlorinated paraffins (SCCPs) have attracted considerable attention for their characteristic of persistent organic pollutants. However, very limited information is available for their toxic effects at environmentally relevant doses, limiting the evaluation of their health risks. In this study, cell viability assay and targeted metabolomic approach was used to evaluate the environmental dose (<100 μg/L) effect of SCCPs on HepG2 cells. Cell viability was found to be decreased with increases in exposure dose of SCCPs. Exposure for 48 h to C10-CPs resulted in a significant reduction in cell viability compared with 24 h, even at 1 μg/L. SCCPs exposure altered the intracellular redox status and caused significant metabolic disruptions. As a kind of peroxisome proliferator, SCCPs specifically stimulated the β-oxidation of unsaturated fatty acids and long-chain fatty acids. Meanwhile, SCCPs exposure disturbed glycolysis and amino acid metabolism, and led to the up-regulation of glutamate metabolism and urea cycle. The toxic effects of SCCPs might mainly involve the perturbation of energy production, protein biosynthesis, fatty acid metabolism, and ammonia recycling.

  17. Time- and concentration-dependent effects of resveratrol in HL-60 and HepG2 cells

    DEFF Research Database (Denmark)

    Stervbo, Ulrik; Vang, Ole; Bonnesen, Christine

    2006-01-01

    Resveratrol, a phytochemical present in grapes, has been demonstrated to inhibit tumourigenesis in animal models. However, the specific mechanism by which resveratrol exerts its anticarcinogenic effect has yet to be elucidated. In the present study, the inhibitory effects of resveratrol on cell...... proliferation and apoptosis were evaluated in the human leukaemia cell line HL-60 and the human hepatoma derived cell line HepG2. We found that after a 2 h incubation period, resveratrol inhibited DNA synthesis in a concentration-dependent manner. The IC50 value was 15 μM in both HL-60 and HepG2 cells. When...... the time of treatment was extended, an increase in IC50 value was observed; for example, at 24 h the IC50 value was 30 μM for HL-60 cells and 60 μM for HepG2 cells. Flow cytometry revealed that cells accumulated in different phases of the cell cycle depending on the resveratrol concentration. Furthermore...

  18. Enhancement of amygdalin activated with β-D-glucosidase on HepG2 cells proliferation and apoptosis.

    Science.gov (United States)

    Zhou, Cunshan; Qian, Lichun; Ma, Haile; Yu, Xiaojie; Zhang, Youzuo; Qu, Wenjuan; Zhang, Xiaoxu; Xia, Wei

    2012-09-01

    The growth inhibition and induction of apoptosis brought by amygdalin and activated with β-D-glucosidase were tested for cytoactivity in HepG2 cells. The MTT viability assay showed that all samples had effects on HepG2 proliferation in dose and time response manners. IC50 of stand-alone amygdalin and activation with β-D-glucosidase on the proliferation of HepG2 cells for 48 h were 458.10 mg/mL and 3.2 mg/mL, respectively. Moreover, apoptotic cells were determined by AO/EB (acridine orange/ethidium bromide) fluorescent staining method and Annexin V-FITC/PI staining flow cytometry cell cycle analysis. With increasing of amygdalin concentration and the incubation time, the apoptotic rate was heightened. Compared with the control, there was significant difference (pamygdalin had no strong anti-HepG2 activity; however the ingredients of amygdalin activated with β-D-glucosidase had a higher and efficient anti-HepG2 activity. It was therefore suggested that this combination strategy may be applicable for treating tumors with a higher activity. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. A polysaccharide from Grifola frondosa relieves insulin resistance of HepG2 cell by Akt-GSK-3 pathway.

    Science.gov (United States)

    Ma, Xiaolei; Zhou, Fuchuan; Chen, Yuanyuan; Zhang, Yuanyuan; Hou, Lihua; Cao, Xiaohong; Wang, Chunling

    2014-07-01

    Grifola frondosa is an important fungal research resource. However, there was little report about hyperglycemic activity of Grifola frondosa polysaccharide on insulin resistance in vitro. In this study, the hypoglycemic activity of a polysaccharide obtained from Grifola frondosa (GFP) on HepG2 cell and hpyerglycemic mechanism were investigated. The purity of the isolated polysaccharides was examined by HPLC. In this research, it was found that GFP enhanced the absorption of glucose of HepG2 cells in a dose dependent manner at 24 h of 30 ugmL⁻¹. GC-MS and FT-IR spectroscopy analysis results showed that glucose and galactose were the dominant monosaccharides in GFP and the major component of GFP was β-pyranoside. Western-blotting results showed that the HepG2 cell model treated with GFP activated the insulin receptor protein (IRS) in the cell membrane and increased phosphorylated-AktSer473 expression, which had an inhibition of glycogen synthase kinase (GSK-3). The down-regulation of GSK-3 stimulated synthesis of intracellular glycogen. The results above suggested that the GFP increased the metabolism of glucose and stimulated synthesis of intracellular glycogen through the Akt/GSK-3 pathway.

  20. Methamphetamine-induced degeneration of dopaminergic neurons involves autophagy and upregulation of dopamine synthesis.

    Science.gov (United States)

    Larsen, Kristin E; Fon, Edward A; Hastings, Teresa G; Edwards, Robert H; Sulzer, David

    2002-10-15

    Methamphetamine (METH) selectively injures the neurites of dopamine (DA) neurons, generally without inducing cell death. It has been proposed that METH-induced redistribution of DA from the vesicular storage pool to the cytoplasm, where DA can oxidize to produce quinones and additional reactive oxygen species, may account for this selective neurotoxicity. To test this hypothesis, we used mice heterozygous (+/-) or homozygous (-/-) for the brain vesicular monoamine uptake transporter VMAT2, which mediates the accumulation of cytosolic DA into synaptic vesicles. In postnatal ventral midbrain neuronal cultures derived from these mice, METH-induced degeneration of DA neurites and accumulation of oxyradicals, including metabolites of oxidized DA, varied inversely with VMAT2 expression. METH administration also promoted the synthesis of DA via upregulation of tyrosine hydroxylase activity, resulting in an elevation of cytosolic DA even in the absence of vesicular sequestration. Electron microscopy and fluorescent labeling confirmed that METH promoted the formation of autophagic granules, particularly in neuronal varicosities and, ultimately, within cell bodies of dopaminergic neurons. Therefore, we propose that METH neurotoxicity results from the induction of a specific cellular pathway that is activated when DA cannot be effectively sequestered in synaptic vesicles, thereby producing oxyradical stress, autophagy, and neurite degeneration.

  1. UPREGULATION OF BNIP3 AND TRANSLOCATION TO MITOCHONDRIA MEDIATES CYANIDE-INDUCED APOPTOSIS IN CORTICAL CELLS

    Science.gov (United States)

    Prabhakaran, K.; Li, L.; Zhang, L.; Borowitz, J.L.; Isom, G.E.

    2008-01-01

    BNIP3, a BH3 domain only Bcl-2 protein, has been identified as a mitochrondrial mediator of hypoxia-induced cell death. Since cyanide produces histotoxic anoxia (chemical hypoxia), the present study was undertaken in primary cortical cells to determine involvement of the BNIP3 signaling pathway in cyanide-induced death. Over a 20 h exposure KCN increased BNIP3 expression, followed by a concentration-related apoptotic death. To determine if BNIP3 plays a role in the cell death, expression was either overexpressed with BNIP3 cDNA (BNIP3+) or knocked down with small interfering RNA (RNAi). In BNIP3+ cells, cyanide-induced apoptotic death was markedly enhanced and preceded by reduction of mitochondrial membrane potential (Δψm), release of cytochrome c from mitochondria and elevated caspase 3 and 7 activity. Pretreatment with the pan caspase inhibitor zVAD-fmk suppressed BNIP3+-mediated cell death, thus confirming a caspase-dependent apoptosis. On the other hand, BNIP3 knock down by RNAi or antagonism of BNIP3 by a transmembrane-deleted dominant-negative mutant (BNIP3ΔTM) markedly reduced cell death. Immunohistochemical imaging showed that cyanide stimulated translocation of BNIP3 from cytosol to mitochondria and displacement studies with BNIP3ΔTM showed that integration of BNIP3 into the mitochondrial outer membrane was necessary for the cell death. In BNIP3+ cells, cyclosporin-A, an inhibitor of mitochondrial pore transition, blocked the cyanide-induced reduction of Δψm and decreased the apoptotic death. These results demonstrate in cortical cells that cyanide induces a rapid upregulation of BNIP3 expression, followed by translocation to the mitochondrial outer membrane to reduceΔψm This was followed by mitochondrial release of cytochrome c to execute a caspase-dependent cell death. PMID:17980495

  2. In HepG2 Cells, Coexisting Carnitine Deficiency Masks Important Indicators of Marginal Biotin Deficiency123

    Science.gov (United States)

    Bogusiewicz, Anna; Boysen, Gunnar; Mock, Donald M

    2015-01-01

    Background: A large number of birth defects are related to nutrient deficiencies; concern that biotin deficiency is teratogenic in humans is reasonable. Surprisingly, studies indicate that increased urinary 3-hydroxyisovalerylcarnitine (3HIAc), a previously validated marker of biotin deficiency, is not a valid biomarker in pregnancy. Objective: In this study we hypothesized that coexisting carnitine deficiency can prevent the increase in 3HIAc due to biotin deficiency. Methods: We used a 2-factor nutrient depletion design to induce isolated and combined biotin and carnitine deficiency in HepG2 cells and then repleted cells with carnitine. To elucidate the metabolic pathogenesis, we quantitated intracellular and extracellular free carnitine, acylcarnitines, and acylcarnitine ratios using liquid chromatography–tandem mass spectrometry. Results: Relative to biotin-sufficient, carnitine-sufficient cells, intracellular acetylcarnitine increased by 90%, propionylcarnitine more than doubled, and 3HIAc increased by >10-fold in biotin-deficient, carnitine-sufficient (BDCS) cells, consistent with a defensive mechanism in which biotin-deficient cells transesterify the acyl-coenzyme A (acyl-CoA) substrates of the biotin-dependent carboxylases to the related acylcarnitines. Likewise, in BDCS cells, the ratio of acetylcarnitine to malonylcarnitine and the ratio of propionylcarnitine to methylmalonylcarnitine both more than tripled, and the ratio of 3HIAc to 3-methylglutarylcarnitine (MGc) increased by >10-fold. In biotin-deficient, carnitine-deficient (BDCD) cells, the 3 substrate-derived acylcarnitines changed little, but the substrate:product ratios were masked to a lesser extent. Moreover, carnitine repletion unmasked biotin deficiency in BDCD cells as shown by increases in acetylcarnitine, propionylcarnitine, and 3HIAc (each increased by >50-fold). Likewise, ratios of acetylcarnitine:malonylcarnitine, propionylcarnitine:methylmalonylcarnitine, and 3HIAc:MGc all increased

  3. Modulation of the pentose phosphate pathway alters phase I metabolism of testosterone and dextromethorphan in HepG2 cells.

    Science.gov (United States)

    Xiao, Wen-jing; Ma, Ting; Ge, Chun; Xia, Wen-juan; Mao, Yong; Sun, Run-bin; Yu, Xiao-yi; Aa, Ji-ye; Wang, Guang-ji

    2015-02-01

    The pentose phosphate pathway (PPP) is involved in the activity of glucose-6-phosphate dehydrogenase (G6PD) and generation of NADPH, which plays a key role in drug metabolism. The aim of this study was to investigate the effects of modulation of the PPP on drug metabolism capacity in vitro. A pair of hepatic cell lines, ie, the cancerous HepG2 cells and normal L02 cells, was used. The expression of CYP450 enzymes, p53 and G6PD in the cells were analyzed. The metabolism of testosterone (TEST, 10 μmol/L) and dextromethorphan (DEM, 1 μmol/L), the two typical substrates for CYP3A4 and CYP2D6, in the cells was examined in the presence of different agents. Both the expression and metabolic activities of CYP3A4 and CYP2D6 were considerably higher in HepG2 cells than in L02 cells. The metabolism of TEST and DEM in HepG2 cells was dose-dependently inhibited by the specific CYP3A4 inhibitor ketoconazole and CYP2D6 inhibitor quinidine. Addition of the p53 inhibitor cyclic PFT-α (5, 25 μmol/L) in HepG2 cells dose-dependently enhanced the metabolism of DEM and TEST, whereas addition of the p53 activator NSC 66811 (3, 10, 25 μmol/L) dose-dependently inhibited the metabolism. Furthermore, addition of the G6PD inhibitor 6-aminonicotinamide (5, 15 μmol/L) in HepG2 cells dose-dependently inhibited the metabolism of DEM and TEST, whereas addition of the PPP activity stimulator menadione (1, 5, 15 μmol/L) dose-dependently enhanced the metabolism. Modulation of p53 and the PPP alters the metabolism of DEM and TEST, suggesting that the metabolic flux pattern of PPP may be closely involved in drug metabolism and the individual variance.

  4. Amiodarone sensitizes human glioma cells but not astrocytes to TRAIL-induced apoptosis via CHOP-mediated DR5 upregulation

    Science.gov (United States)

    Kim, In Young; Kang, You Jung; Yoon, Mi Jin; Kim, Eun Hee; Kim, Seung U; Kwon, Taeg Kyu; Kim, In Ah; Choi, Kyeong Sook

    2011-01-01

    Amiodarone is a widely used anti-arrhythmic drug that inhibits diverse ion channels, including the Na+/Ca2+ exchanger (NCX), L-type Ca2+ channels, and Na+ channels. Here, we report that subtoxic doses of amiodarone and tumor necrosis factor–related apoptosis-inducing ligand (TRAIL) synergistically induced apoptosis of various glioma cells. Treatment of U251MG glioma cells with amiodarone increased intracellular Ca2+ levels and enhanced the expression of the endoplasmic reticulum (ER) stress-inducible transcription factor C/EBP homologous protein (CHOP). This upregulation of CHOP was followed by marked upregulation of the TRAIL receptor, DR5. Suppression of DR5 expression by small interfering (si) RNAs almost completely blocked amiodarone/TRAIL-induced apoptosis in U251MG glioma cells, demonstrating that DR5 is critical to this cell death. siRNA-mediated CHOP suppression reduced amiodarone-induced DR5 upregulation and attenuated the cell death induced by amiodarone plus TRAIL. In addition, omitting Ca2+ from the external medium using ethylene glycol tetraacetic acid markedly inhibited this cell death, reducing the protein levels of CHOP and DR5. These results suggest that amiodarone-induced influx of Ca2+ plays an important role in sensitizing U251MG cells to TRAIL-mediated apoptosis through CHOP-mediated DR5 upregulation. Furthermore, subtoxic doses of bepridil and cibenzoline, two other anti-arrhythmic drugs with NCX-inhibitor activity, also sensitized glioma cells to TRAIL-mediated apoptosis, via the upregulation of both CHOP and DR5. Notably, amiodarone/TRAIL cotreatment did not induce cell death in astrocytes, nor did it affect the expression of CHOP or DR5 in these cells. These results collectively suggest that a combined regimen of amiodarone plus TRAIL may offer an effective therapeutic strategy for safely and selectively treating resistant gliomas. PMID:21292685

  5. Amiodarone sensitizes human glioma cells but not astrocytes to TRAIL-induced apoptosis via CHOP-mediated DR5 upregulation.

    Science.gov (United States)

    Kim, In Young; Kang, You Jung; Yoon, Mi Jin; Kim, Eun Hee; Kim, Seung U; Kwon, Taeg Kyu; Kim, In Ah; Choi, Kyeong Sook

    2011-03-01

    Amiodarone is a widely used anti-arrhythmic drug that inhibits diverse ion channels, including the Na(+)/Ca(2+) exchanger (NCX), L-type Ca(2+) channels, and Na(+) channels. Here, we report that subtoxic doses of amiodarone and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) synergistically induced apoptosis of various glioma cells. Treatment of U251MG glioma cells with amiodarone increased intracellular Ca(2+) levels and enhanced the expression of the endoplasmic reticulum (ER) stress-inducible transcription factor C/EBP homologous protein (CHOP). This upregulation of CHOP was followed by marked upregulation of the TRAIL receptor, DR5. Suppression of DR5 expression by small interfering (si) RNAs almost completely blocked amiodarone/TRAIL-induced apoptosis in U251MG glioma cells, demonstrating that DR5 is critical to this cell death. siRNA-mediated CHOP suppression reduced amiodarone-induced DR5 upregulation and attenuated the cell death induced by amiodarone plus TRAIL. In addition, omitting Ca(2+) from the external medium using ethylene glycol tetraacetic acid markedly inhibited this cell death, reducing the protein levels of CHOP and DR5. These results suggest that amiodarone-induced influx of Ca(2+) plays an important role in sensitizing U251MG cells to TRAIL-mediated apoptosis through CHOP-mediated DR5 upregulation. Furthermore, subtoxic doses of bepridil and cibenzoline, two other anti-arrhythmic drugs with NCX-inhibitor activity, also sensitized glioma cells to TRAIL-mediated apoptosis, via the upregulation of both CHOP and DR5. Notably, amiodarone/TRAIL cotreatment did not induce cell death in astrocytes, nor did it affect the expression of CHOP or DR5 in these cells. These results collectively suggest that a combined regimen of amiodarone plus TRAIL may offer an effective therapeutic strategy for safely and selectively treating resistant gliomas.

  6. Centrifugal gravity-induced BMP4 induces chondrogenic differentiation of adipose-derived stem cells via SOX9 upregulation.

    Science.gov (United States)

    Jang, Yeonsue; Jung, Hyerin; Nam, Yoojun; Rim, Yeri Alice; Kim, Juryun; Jeong, Sang Hoon; Ju, Ji Hyeon

    2016-12-08

    Cartilage does not have the capability to regenerate itself. Therefore, stem cell transplantation is a promising therapeutic approach for impaired cartilage. For stem cell transplantation, in vitro enrichment is required; however, stem cells not only become senescent but also lose their differentiation potency during this process. In addition, cytokines are normally used for chondrogenic differentiation induction of stem cells, which is highly expensive and needs an additional step to culture. In this study, we introduced a novel method to induce chondrogenic differentiation of adipose-derived stem cells (ASCs), which are more readily available than bone marrow-derived mesenchymal stem cells(bMSCs), using centrifugal gravity (CG). ASCs were stimulated by loading different degrees of CG (0, 300, 600, 1200, 2400, and 3600 g) to induce chondrogenic differentiation. The expression of chondrogenic differentiation-related genes was examined by RT-PCR, real-time PCR, and western blot analyses. The chondrogenic differentiation of ASCs stimulated with CG was evaluated by comparing the expression of positive markers [aggrecan (ACAN) and collagen type II alpha 1 (COL2A1)] and negative markers (COL1 and COL10) with that in ASCs stimulated with transforming growth factor (TGF)-β1 using micromass culture, immunofluorescence, and staining (Alcian Blue and Safranin O). Expression of SOX9 and SOX5 was upregulated by CG (2400 g for 30 min). Increased expression of ACAN and COL2A1 (positive markers) was detected in monolayer-cultured ASCs after CG stimulation, whereas that of COL10 (a negative marker) was not. Expression of bone morphogenetic protein (BMP) 4, an upstream stimulator of SOX9, was upregulated by CG, which was inhibited by Dorsomorphin (an inhibitor of BMP4). Increased expression of proteoglycan, a major component of cartilage, was confirmed in the micromass culture of ASCs stimulated with CG by Alcian Blue and Safranin O staining. Chondrogenic differentiation of

  7. Up-Regulated Expression of Matrix Metalloproteinases in Endothelial Cells Mediates Platelet Microvesicle-Induced Angiogenesis.

    Science.gov (United States)

    Sun, Cheng; Feng, Shi-Bin; Cao, Zheng-Wang; Bei, Jun-Jie; Chen, Qiang; Zhao, Wei-Bo; Xu, Xian-Jie; Zhou, Zhou; Yu, Zheng-Ping; Hu, Hou-Yuan

    2017-01-01

    Platelet microvesicles (PMVs) contribute to angiogenesis and vasculogenesis, but the mechanisms underlying these contributions have not been fully elucidated. In the present study, we investigated whether PMVs regulate the angiogenic properties of endothelial cells (ECs) via mechanisms extending beyond the transport of angiogenic regulators from platelets. In vitro Matrigel tube formation assay and in vivo Matrigel plug assay were used to evaluate the pro-angiogenic activity of PMVs. The effects of PMVs on the migration of human umbilical vein endothelial cells (HUVECs) were detected by transwell assay and wound-healing assay. Real-time PCR and western blot were conducted to examine mRNA and protein expression of pro-angiogenic factors in HUVECs. Matrix metalloproteinase (MMP) activity was assayed by gelatin zymography. Moreover, the effects of specific MMP inhibitors were tested. PMVs promoted HUVEC capillary-like network formation in a dose-dependent manner. Meanwhile, PMVs dose-dependently facilitated HUVEC migration. Levels of MMP-2 and MMP-9 expression and activity were up-regulated in HUVECs stimulated with PMVs. Inhibition of MMPs decreased their pro-angiogenic and pro-migratory effects on HUVECs. Moreover, we confirmed the pro-angiogenic activity of PMVs in vivo in mice with subcutaneous implantation of Matrigel, and demonstrated that blockade of MMPs attenuated PMV-induced angiogenesis. The findings of our study indicate that PMVs promote angiogenesis by up-regulating MMP expression in ECs via mechanism extending beyond the direct delivery of angiogenic factors. © 2017 The Author(s). Published by S. Karger AG, Basel.

  8. Hypergravity upregulates renal inducible nitric oxide synthase expression and nitric oxide production.

    Science.gov (United States)

    Yoon, Gun; Oh, Choong Sik; Kim, Hyun-Soo

    2016-05-24

    Exposure to hypergravity severely decreases renal blood flow, potentially causing renal dysfunction. Nitric oxide (NO), which is endogenously synthesized by inducible NO synthase (iNOS), plays an important role in the regulation of renal function. The purpose of this study was to examine the effect of hypergravity exposure on the production of NO in kidneys. To determine whether hypergravity induces renal hypoxia and alters renal iNOS expression and NO production, mice were exposed to short-term hypergravity at +3Gz for 1 h. The time course of iNOS mRNA expression, hypoxia-inducible factor (HIF)-1α expression, and NO production was examined. Renal HIF-1α levels were significantly elevated immediately after centrifugation, and this increase was sustained for 3 h post-exposure. iNOS mRNA levels were also significantly increased immediately after exposure and were maintained during the reoxygenation period. Immunohistochemical staining for iNOS revealed that the cortical tubular epithelium exhibited moderate to strong cytoplasmic iNOS immunoreactivity immediately after hypergravity exposure and during the reoxygenation period. The time course of NO production was similar to that of iNOS expression. Our results suggest that both hypoxia and reoxygenation might be involved in the upregulation of HIF-1α in the kidneys of mice exposed to hypergravity. Significant increases in renocortical iNOS expression immediately after centrifugation and during the reoxygenation period suggest that iNOS expression induced by hypergravity exposure might play a protective role against hypoxia/reoxygenation injury in the renal cortex. Further investigations are necessary to clarify the role of iNOS and NO in kidneys exposed to hypergravity.

  9. Hypoxia Induces Autophagy through Translational Up-Regulation of Lysosomal Proteins in Human Colon Cancer Cells.

    Directory of Open Access Journals (Sweden)

    Ming-Chih Lai

    Full Text Available Hypoxia occurs in a wide variety of physiological and pathological conditions, including tumorigenesis. Tumor cells have to adapt to hypoxia by altering their gene expression and protein synthesis. Here, we showed that hypoxia inhibits translation through activation of PERK and inactivation of mTOR in human colon cancer HCT116 cells. Prolonged hypoxia (1% O2, 16 h dramatically inhibits general translation in HCT116 cells, yet selected mRNAs remain efficiently translated under such a condition. Using microarray analysis of polysome- associated mRNAs, we identified a large number of hypoxia-regulated genes at the translational level. Efficiently translated mRNAs during hypoxia were validated by polysome profiling and quantitative real-time RT-PCR. Pathway enrichment analysis showed that many of the up-regulated genes are involved in lysosome, glycan and lipid metabolism, antigen presentation, cell adhesion, and remodeling of the extracellular matrix and cytoskeleton. The majority of down-regulated genes are involved in apoptosis, ubiquitin-mediated proteolysis, and oxidative phosphorylation. Further investigation showed that hypoxia induces lysosomal autophagy and mitochondrial dysfunction through translational regulation in HCT116 cells. The abundance of several translation factors and the mTOR kinase activity are involved in hypoxia-induced mitochondrial autophagy in HCT116 cells. Our studies highlight the importance of translational regulation for tumor cell adaptation to hypoxia.

  10. Anoxia-Induced Up-Regulation of Interleukin-8 in Human Malignant Melanoma

    Science.gov (United States)

    Kunz, Manfred; Hartmann, Anke; Flory, Egbert; Toksoy, Atiye; Koczan, Dirk; Thiesen, Hans-Jürgen; Mukaida, Nafoumi; Neumann, Manfred; Rapp, Ulf Rüdiger; Bröcker, Eva-Bettina; Gillitzer, Reinhard

    1999-01-01

    Besides its proinflammatory properties, interleukin-8 (IL-8) has been suggested as an important promoter for melanoma growth. To study the role of IL-8 in melanoma biology, we determined the in vivo expression of IL-8 mRNA by in situ hybridization in primary melanoma lesions and metastases. High levels of melanoma cell-associated IL-8-specific transcripts were exclusively detected in close vicinity of necrotic/hypoxic areas of melanoma metastases, whereas both in primary melanomas and in non-necrotic metastases IL-8 expression was low or absent. To analyze further the up-regulation of IL-8 mRNA expression in necrotic/hypoxic tumor areas, human melanoma cell lines of different aggressiveness exposed to severe hypoxic stress (anoxia) were used as an in vitro model. Anoxia induced IL-8 mRNA and protein expression in the highly aggressive/metastatic cell lines MV3 and BLM but not in the low aggressive cell lines IF6 and 530. As shown by IL-8 promoter-dependent reporter gene analysis and mRNA stability assays, elevated mRNA levels in melanoma cells were due to both enhanced transcriptional activation and enhanced IL-8 mRNA stability. Interestingly, transcriptional activation was abolished by mutations in the AP-1 and the NF-κB-like binding motifs, indicating that both sites are critical for IL-8 induction. Concomitantly, anoxia induced an enhanced binding activity of AP-1 and NF-κB transcription factors only in the highly aggressive cells. From our in vitro and in vivo data we suggest that anoxia-induced regulation of IL-8 might be a characteristic feature of aggressive tumor cells, thus indicating that IL-8 might play a critical role for tumor progression in human malignant melanoma. PMID:10487833

  11. Bleomycin induces upregulation of lysyl oxidase in cultured human fetal lung fibroblasts

    Science.gov (United States)

    Chen, Li-jun; Li, Wan-de; Li, Shi-feng; Su, Xing-wen; Lin, Guang-yun; Huang, Yi-jun; Yan, Guang-mei

    2010-01-01

    Aim: To investigate the mechanism of bleomycin (BLM)-induced pulmonary fibrosis. Methods: Cultured human fetal lung fibroblast (HLF) cells were exposed to bleomycin (BLM) at 0–30 μg/mL for 24 h. Western blot analysis was used to detect lysyl oxidase (LO) protein expression. Real-time RT-PCR was used to detect LO mRNA level. LO catalytic activity was measured using diaminopentane as a substrate and Amplex red as a hydrogen peroxide probe. Copper (Cu) concentration was detected by flame atomic absorption spectrophotometry. Results: Exposure of HLF cells to BLM at 10 μg/mL and 30 μg/mL increased LO catalytic activity to 130% and 158% of the control in the conditioned media. The expression of LO mRNA was increased to 5.5-fold of the control in HLF cells exposure to BLM at 3 μg/mL. BLM at 3 μg/mL also increased the expression of 46 kDa preproLO, 50 kDa proLO and 32 kDa mature LO to 219%, 130%, and 135% of the control, respectively. The Cu concentrations in conditioned media of cultured HLF cells exposed to BLM (10 and 30 μg/mL) were increased significantly to 1.48 and 2.46-fold of the control, respectively. Conclusion: Bleomycin induces upregulation of LO in cultured human fetal lung fibroblasts, which may be the mechanism of bleomycin-induced pulmonary fibrosis. PMID:20418892

  12. LXR agonist increases apoE secretion from HepG2 spheroid, together with an increased production of VLDL and apoE-rich large HDL

    Directory of Open Access Journals (Sweden)

    Koike Kazuhiko

    2011-08-01

    Full Text Available Abstract Background The physiological regulation of hepatic apoE gene has not been clarified, although the expression of apoE in adipocytes and macrophages has been known to be regulated by LXR. Methods and Results We investigated the effect of TO901317, a LXR agonist, on hepatic apoE production utilizing HepG2 cells cultured in spheroid form, known to be more differentiated than HepG2 cells in monolayer culture. Spheroid HepG2 cells were prepared in alginate-beads. The secretions of albumin, apoE and apoA-I from spheroid HepG2 cells were significantly increased compared to those from monolayer HepG2 cells, and these increases were accompanied by increased mRNA levels of apoE and apoA-I. Several nuclear receptors including LXRα also became abundant in nuclear fractions in spheroid HepG2 cells. Treatment with TO901317 significantly increased apoE protein secretion from spheroid HepG2 cells, which was also associated with the increased expression of apoE mRNA. Separation of the media with FPLC revealed that the production of apoE-rich large HDL particles were enhanced even at low concentration of TO901317, and at higher concentration of TO901317, production of VLDL particles increased as well. Conclusions LXR activation enhanced the expression of hepatic apoE, together with the alteration of lipoprotein particles produced from the differentiated hepatocyte-derived cells. HepG2 spheroids might serve as a good model of well-differentiated human hepatocytes for future investigations of hepatic lipid metabolism.

  13. Upregulation of IFN-Inducible and Damage-Response Pathways in Chronic Graft-versus-Host Disease.

    Science.gov (United States)

    Hakim, Frances T; Memon, Sarfraz; Jin, Ping; Imanguli, Matin M; Wang, Huan; Rehman, Najibah; Yan, Xiao-Yi; Rose, Jeremy; Mays, Jacqueline W; Dhamala, Susan; Kapoor, Veena; Telford, William; Dickinson, John; Davis, Sean; Halverson, David; Naik, Haley B; Baird, Kristin; Fowler, Daniel; Stroncek, David; Cowen, Edward W; Pavletic, Steven Z; Gress, Ronald E

    2016-11-01

    Although chronic graft-versus-host disease (CGVHD) is the primary nonrelapse complication of allogeneic transplantation, understanding of its pathogenesis is limited. To identify the main operant pathways across the spectrum of CGVHD, we analyzed gene expression in circulating monocytes, chosen as in situ systemic reporter cells. Microarrays identified two interrelated pathways: 1) IFN-inducible genes, and 2) innate receptors for cellular damage. Corroborating these with multiplex RNA quantitation, we found that multiple IFN-inducible genes (affecting lymphocyte trafficking, differentiation, and Ag presentation) were concurrently upregulated in CGVHD monocytes compared with normal subjects and non-CGVHD control patients. IFN-inducible chemokines were elevated in both lichenoid and sclerotic CGHVD plasma and were linked to CXCR3(+) lymphocyte trafficking. Furthermore, the levels of the IFN-inducible genes CXCL10 and TNFSF13B (BAFF) were correlated at both the gene and the plasma levels, implicating IFN induction as a factor in elevated BAFF levels in CGVHD. In the second pathway, damage-/pathogen-associated molecular pattern receptor genes capable of inducing type I IFN were upregulated. Type I IFN-inducible MxA was expressed in proportion to CGVHD activity in skin, mucosa, and glands, and expression of TLR7 and DDX58 receptor genes correlated with upregulation of type I IFN-inducible genes in monocytes. Finally, in serial analyses after transplant, IFN-inducible and damage-response genes were upregulated in monocytes at CGVHD onset and declined upon therapy and resolution in both lichenoid and sclerotic CGVHD patients. This interlocking analysis of IFN-inducible genes, plasma analytes, and tissue immunohistochemistry strongly supports a unifying hypothesis of induction of IFN by innate response to cellular damage as a mechanism for initiation and persistence of CGVHD.

  14. Hepatoprotective Effect of Aqueous Extract from the Seeds of Orychophragmus violaceus against Liver Injury in Mice and HepG2 Cells.

    Science.gov (United States)

    Huo, Xiaowei; Liu, Chenqi; Gao, Li; Xu, Xudong; Zhu, Nailiang; Cao, Li

    2017-06-15

    Orychophragmus violaceus ( O. violaceus ) is a kind of edible wild herb in north China and its seeds have medical potential, however, the effect of O. violaceus seeds on liver injury and the mechanism of action remains poorly understood. Thus, the purpose of the present study is to investigate the effect of O. violaceus seeds on liver injury and further explore the molecular mechanism of the beneficial effects using aqueous extract from the seeds of O. violaceus (AEOV). Mice were orally administrated with saline, AEOV, and biphenyldicarboxylate for 4 days, and were then injected subcutaneously with 0.1% carbon tetrachloride (CCl₄) dissolved in corn oil. Sixteen hours later, mice were sacrificed and blood samples were collected. Then, the serum was separated and used for biochemical assay. Livers were excised and were routinely processed for histological examinations. Enzyme activities and protein levels in liver homogenates were detected using commercial kits or by western blot analysis. Additionally, the hepatoprotective effect of AEOV in vitro was evaluated using epigoitrin, the major alkaloid compound isolated from AEOV. We found that AEOV attenuated liver injury induced by CCl₄ as evidenced by decreased levels of alanine aminotransferase (ALT) and aminotransferase (AST) in serum, improvement of liver histopathological changes, and substantial attenuation of oxidative stress and inflammation via regulation of nuclear factor-erythroid 2-related factor-2 (Nrf2) and nuclear factor κB (NFκB) pathways. These effects of AEOV were comparable to that of biphenyldicarboxylate which was commonly used as a hepatoprotective reference. Moreover, pretreatment of HepG2 cells with epigoitrin improved cell viability, decreased lactate dehydrogenase (LDH) and malondialdehyde (MDA) levels, increased superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity, attenuated the NFκB pathway, and elevated the Nrf2 pathway after exposure to H₂O₂. These results

  15. Hepatoprotective Effect of Aqueous Extract from the Seeds of Orychophragmus violaceus against Liver Injury in Mice and HepG2 Cells

    Directory of Open Access Journals (Sweden)

    Xiaowei Huo

    2017-06-01

    Full Text Available Orychophragmus violaceus (O. violaceus is a kind of edible wild herb in north China and its seeds have medical potential, however, the effect of O. violaceus seeds on liver injury and the mechanism of action remains poorly understood. Thus, the purpose of the present study is to investigate the effect of O. violaceus seeds on liver injury and further explore the molecular mechanism of the beneficial effects using aqueous extract from the seeds of O. violaceus (AEOV. Mice were orally administrated with saline, AEOV, and biphenyldicarboxylate for 4 days, and were then injected subcutaneously with 0.1% carbon tetrachloride (CCl4 dissolved in corn oil. Sixteen hours later, mice were sacrificed and blood samples were collected. Then, the serum was separated and used for biochemical assay. Livers were excised and were routinely processed for histological examinations. Enzyme activities and protein levels in liver homogenates were detected using commercial kits or by western blot analysis. Additionally, the hepatoprotective effect of AEOV in vitro was evaluated using epigoitrin, the major alkaloid compound isolated from AEOV. We found that AEOV attenuated liver injury induced by CCl4 as evidenced by decreased levels of alanine aminotransferase (ALT and aminotransferase (AST in serum, improvement of liver histopathological changes, and substantial attenuation of oxidative stress and inflammation via regulation of nuclear factor-erythroid 2-related factor-2 (Nrf2 and nuclear factor κB (NFκB pathways. These effects of AEOV were comparable to that of biphenyldicarboxylate which was commonly used as a hepatoprotective reference. Moreover, pretreatment of HepG2 cells with epigoitrin improved cell viability, decreased lactate dehydrogenase (LDH and malondialdehyde (MDA levels, increased superoxide dismutase (SOD and glutathione peroxidase (GSH-Px activity, attenuated the NFκB pathway, and elevated the Nrf2 pathway after exposure to H2O2. These results

  16. Lack of upregulation of epidermal fatty acid binding protein in dithranol induced irritation.

    NARCIS (Netherlands)

    Kucharekova, M.; Vissers, W.H.P.M.; Schalkwijk, J.; Kerkhof, P.C.M. van de; Valk, P.G.M. van der

    2003-01-01

    The exact role of epidermal fatty acid binding protein (E-FABP) in skin is unknown. A restoration of the barrier function may be associated with an upregulation of E-FABP. Moreover, E-FABP is upregulated in a variety of cells in response to oxidative stress. A recent observation that dithranol

  17. Upregulation of TRPC1 contributes to contractile function in isoproterenol-induced hypertrophic myocardium of rat.

    Science.gov (United States)

    Chen, Mo-Si; Xiao, Jun-Hua; Wang, Yong; Xu, Bo-Ming; Gao, Lu; Wang, Jia-Ling

    2013-01-01

    The transient receptor potential canonical channel 1 (TRPC1) is a crucial component of the stretch-activated ion channels (SACs). The objective of this research was to demonstrate the contribution of TRPC1 in maintaining cardiac contractile function in the hypertrophic myocardium. Hypertrophic rat hearts were induced by injecting isoproterenol intraperitoneally, and the expressions of TRPC1/3/6 and Na(+)/Ca(2+) exchanger 1 (NCX1) proteins were analyzed by Western blot. The intracellular calcium images, the action potential of myocardium, the length-dependent contractile force of ventricle muscle and the cardiac output of isolated heart were investigated. The expression of TRPC1 was increased in the hypertrophic myocardium. After being stretched, the ascendant amplitude of the increase in the intracellular calcium ion concentration ([Ca(2+)]i) in the hypertrophic myocardium was higher than that in the normal myocardium. The increase of the APD50 and the amplitude of the membrane potential depolarization were more significant in the hypertrophic myocardium after the activation of SACs. When the heart preparations were perfused with Tyrode's solution, there was no difference in the cardiac systolic function between the cardiac hypertrophy group and the control group. Gadolinium, a SACs blocker, reduced the length-dependent contractile force and suppressed the ascending limb of the Frank-Starling curves in the hypertrophic heart. The upregulation of TRPC1 contributes to the contractile function in the hypertrophic myocardium by increasing [Ca(2+)]i through the SACs. © 2013 S. Karger AG, Basel

  18. Peripheral inflammation induces up-regulation of TRPV2 expression in rat DRG.

    Science.gov (United States)

    Shimosato, Goshun; Amaya, Fumimasa; Ueda, Masashi; Tanaka, Yoshifumi; Decosterd, Isabelle; Tanaka, Masaki

    2005-12-15

    The transient receptor potential vanilloid subfamily member 2 (TRPV2) is a cation channel activated by temperatures above 52 degrees C. To analyze the contribution of TRPV2 to the development of inflammation-induced hyperalgesia, the expression of TRPV2 in primary sensory neurons was analyzed after intraplantar injection of complete Freund's adjuvant (CFA). Using specific antibodies, an increase in TRPV2-expressing neurons was identified after inflammation. TRPV2 expression is concentrated in a subset of medium-sized dorsal root ganglion neurons, independent of transient receptor potential vanilloid subfamily member 1 (TRPV1) expression. A similar distribution of TRPV2 was observed after inflammation. Intraplantar injection of nerve growth factor increased TRPV1 expression but not TRPV2, suggesting that induction of TRPV2 expression is driven by a mechanism distinct from that for TRPV1. Heat hyperalgesia assessment after chemical desensitization of TRPV1 by resiniferatoxin demonstrates a possible role for TRPV2 in inflammation at high temperatures (>56 degrees C). These results suggest that TRPV2 upregulation contributes to peripheral sensitization during inflammation and is responsible for pain hypersensitivity to noxious high temperature stimuli.

  19. Caffeine Induces the Stress Response and Up-Regulates Heat Shock Proteins in Caenorhabditis elegans.

    Science.gov (United States)

    Al-Amin, Mohammad; Kawasaki, Ichiro; Gong, Joomi; Shim, Yhong-Hee

    2016-02-01

    Caffeine has both positive and negative effects on physiological functions in a dose-dependent manner. C. elegans has been used as an animal model to investigate the effects of caffeine on development. Caffeine treatment at a high dose (30 mM) showed detrimental effects and caused early larval arrest. We performed a comparative proteomic analysis to investigate the mode of action of high-dose caffeine treatment in C. elegans and found that the stress response proteins, heat shock protein (HSP)-4 (endoplasmic reticulum [ER] chaperone), HSP-6 (mitochondrial chaperone), and HSP-16 (cytosolic chaperone), were induced and their expression was regulated at the transcriptional level. These findings suggest that high-dose caffeine intake causes a strong stress response and activates all three stress-response pathways in the worms, including the ER-, mitochondrial-, and cytosolic pathways. RNA interference of each hsp gene or in triple combination retarded growth. In addition, caffeine treatment stimulated a food-avoidance behavior (aversion phenotype), which was enhanced by RNAi depletion of the hsp-4 gene. Therefore, up-regulation of hsp genes after caffeine treatment appeared to be the major responses to alleviate stress and protect against developmental arrest.

  20. Attenuation of ethanol withdrawal by ceftriaxone-induced upregulation of glutamate transporter EAAT2.

    Science.gov (United States)

    Abulseoud, Osama A; Camsari, Ulas M; Ruby, Christina L; Kasasbeh, Aimen; Choi, Sun; Choi, Doo-Sup

    2014-06-01

    Alcohol withdrawal syndrome (AWS) is a potentially fatal outcome of severe alcohol dependence that presents a significant challenge to treatment. Although AWS is thought to be driven by a hyperglutamatergic brain state, benzodiazepines, which target the GABAergic system, comprise the first line of treatment for AWS. Using a rat model of ethanol withdrawal, we tested whether ceftriaxone, a β-lactam antibiotic known to increase the expression and activity of glutamate uptake transporter EAAT2, reduces the occurrence or severity of ethanol withdrawal manifestations. After a 2-week period of habituation to ethanol in two-bottle choice, alcohol-preferring (P) and Wistar rats received ethanol (4.0 g/kg) every 6 h for 3-5 consecutive days via gavage. Rats were then deprived of ethanol for 48 h during which time they received ceftriaxone (50 or 100 mg/kg, IP) or saline twice a day starting 12 h after the last ethanol administration. Withdrawal manifestations were captured by continuous video recording and coded. The evolution of ethanol withdrawal was markedly different for P rats vs Wistar rats, with withdrawal manifestations occurring >12 h later in P rats than in Wistar rats. Ceftriaxone 100 mg/kg per injection twice per day (200 mg/kg/day) reduced or abolished all manifestations of ethanol withdrawal in both rat variants and prevented withdrawal-induced escalation of alcohol intake. Finally, ceftriaxone treatment was associated with lasting upregulation of ethanol withdrawal-induced downregulation of EAAT2 in the striatum. Our data support the role of ceftriaxone in alleviating alcohol withdrawal and open a novel pharmacologic avenue that requires clinical evaluation in patients with AWS.

  1. Piceatannol induced apoptosis through up-regulation of microRNA-181a in melanoma cells.

    Science.gov (United States)

    Du, Maotao; Zhang, Zhong; Gao, Tao

    2017-10-17

    Melanoma took top position among the lethal cancers and, despite there have been some great attempts made to increase the natural life of patients with metastatic disease, long-lasting and complete remissions are few. Piceatannol, owns the similar function as resveratrol, has been defined as an anti-cancer agent playing important role in inhibition of proliferation, migration and metastasis in various cancer. Thus, we aim to investigate the anti-cancer effect and mechanisms of piceatannol in melanoma cells. Melanoma cell lines WM266-4 and A2058 were treated either with or without piceatannol. Cell viability and cell apoptosis were assessed by using MTT and Annexin V/PI assay, respectively. Cells were transfected with specific miRNA using Lipfectamine 2000. miRNA bingding ability to 3'-UTR region within specific gene was assed by firefly luciferase analysis. Gene and protein expression was eveluated by qRT-PCR and western blot analysis, respectively. Our study showed that piceatannol inhibited WM266-4 and A2058 cells growth and induced apoptosis. Totally, 16 differentially expressed miRNAs were screened out including 8 up-regulated and 8 down-regulated miRNAs. Expression level of miR-181a is significantly higher in piceatannol-treated cells than normal control and is lower in melanoma cancer tissues than its adjacent normal tissues. Bcl-2 is a target gene of miR-181a. Moreover, silencing of miR-181a reverses the decrease of cell viability induced by piceatannol in WM266-4 and A2058 cells. Taken together, present study uncovered the ability of piceatannol to repress melanoma cell growth and clarified the contribution of miR-181a in the anticancer role of piceatannol. The present study proposes that piceatannol can be taken into account to be a hopeful anticancer agent for melanoma.

  2. The toxicity study of synthesized inverse carnosine peptide analogues on HepG2 and HT-29 cells

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    Mohammad Hassan Houshdar Tehrani

    2018-01-01

    Full Text Available Objective: Cancer has risen as the main cause of diseases with the highest rate of mortality in the world. Drugs used in cancer, usually demonstrate side effects on normal tissues. On the other hand, anticancer small peptides, effective on target tissues, should be safe on healthy organs, as being naturally originated compounds. In addition, they may have good pharmacokinetic properties. carnosine, a natural dipeptide, has shown many biological functions, including anti-oxidant, anti-senescence, anti-inflammatory and anticancer activities. This study, with the aim of introducing new anticancer agents with better properties, is focused on the synthesis and cytotoxic evaluation of some peptide analogues of carnosine. Materials and Methods: The cytotoxic activity of the synthesized peptides, prepared by the solid-phase peptide synthesis method, was evaluated against two cell lines of HepG2 and HT-29 using MTT assay, lactate dehydrogenase (LDH assay and flow­ cytometry analysis. Results: Linear and cyclic analogues of carnosine peptide showed cytotoxicity, demonstrated by several experiments, against HepG2 and HT-29 cell lines with mean IC50 values ranging from 9.81 to 16.23 µg/ml. Among the peptides, compounds 1c, 3c and 6b (linear analogue of 3c showed a considerable toxic activity on the cancerous cell lines. Conclusion: The cyclic peptide analogues of carnosine withHis-β-Ala-­Pro-β-Ala-­His (1c and β-Ala-­His- Pro­-­His-­β-Ala (3c sequences showed cytotoxic activity on cancerous cells of HepG2 and HT-29, better than carnosine, and thus can be good candidates to develop new anticancer agents. The mechanism of cytotoxicity may be through cell apoptosis.

  3. Hypocholesterolemic mechanism of phenolics-enriched extract from Moringa oleifera leaves in HepG2 cell lines

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    Peera Tabboon

    2016-04-01

    Full Text Available Previous studies have demonstrated the hypolipidemic activity of Moringa oleifera (MO leaves via lowering serum levels of cholesterol, but the mechanism of action is unknown. In this study, we demonstrated the hypocholesterolemic mechanism of a phenolics-enriched extract of Moringa oleifera leaf (PMO in HepG2 cells. When compared to the control treatment, PMO significantly decreased total intracellular cholesterol, inhibited the activity of HMG CoA reductase in a dosedependent manner and enhanced LDL receptor binding activity. Moreover, PMO also significantly increased the genetic expressions of HMG CoA reductase and LDL receptor.

  4. Trigeminal nerve injury-induced thrombospondin-4 up-regulation contributes to orofacial neuropathic pain states in a rat model.

    Science.gov (United States)

    Li, K-W; Kim, D-S; Zaucke, F; Luo, Z D

    2014-04-01

    Injury to the trigeminal nerve often results in the development of chronic pain states including tactile allodynia, or hypersensitivity to light touch, in orofacial area, but its underlying mechanisms are poorly understood. Peripheral nerve injury has been shown to cause up-regulation of thrombospondin-4 (TSP4) in dorsal spinal cord that correlates with neuropathic pain development. In this study, we examined whether injury-induced TSP4 is critical in mediating orofacial pain development in a rat model of chronic constriction injury to the infraorbital nerve. Orofacial sensitivity to mechanical stimulation was examined in a unilateral infraorbital nerve ligation rat model. The levels of TSP4 in trigeminal ganglia and associated spinal subnucleus caudalis and C1/C2 spinal cord (Vc/C2) from injured rats were examined at time points correlating with the initiation and peak orofacial hypersensitivity. TSP4 antisense and mismatch oligodeoxynucleotides were intrathecally injected into injured rats to see if antisense oligodeoxynucleotide treatment could reverse injury-induced TSP4 up-regulation and orofacial behavioural hypersensitivity. Our data indicated that trigeminal nerve injury induced TSP4 up-regulation in Vc/C2 at a time point correlated with orofacial tactile allodynia. In addition, intrathecal treatment with TSP4 antisense, but not mismatch, oligodeoxynucleotides blocked both injury-induced TSP4 up-regulation in Vc/C2 and behavioural hypersensitivity. Our data support that infraorbital nerve injury leads to TSP4 up-regulation in trigeminal spinal complex that contributes to orofacial neuropathic pain states. Blocking this pathway may provide an alternative approach in management of orofacial neuropathic pain states. © 2013 European Pain Federation - EFIC®

  5. Polychlorinated biphenyl quinone metabolites lead to oxidative stress in HepG2 cells and the protective role of dihydrolipoic acid.

    Science.gov (United States)

    Liu, Jing; Song, Erqun; Liu, Lichao; Ma, Xiaoyan; Tian, Xingguo; Dong, Hui; Song, Yang

    2012-09-01

    Parent polychlorinated biphenyls (PCBs) have been shown to induce cellular oxidative stress. However, the effects of PCB active metabolites have not been extensively investigated. Parent PCBs are first converted to hydroquinone metabolites via cytochrome P-450-catalyzed hydroxylation, and the hydroquinone metabolites are then further oxidized into the corresponding quinone metabolites. Quinones are responsible for a wide range of toxic effects because of their high reactivity. Previous studies have suggested that reactive oxygen species (ROS) play important roles in multiple toxic mechanisms. In this context, the present study was undertaken to investigate oxidative stress resulting from treatment with PCB quinones in HepG2 cells. The protective effects resulting from co-administration of dihydrolipoic acid (DH-LA) were also investigated. We have found that exposure to PCB quinones leads to: (1) a decrease in cell viability; (2) an increase in both the total ROS production and superoxide production; (3) only 3Cl-PCBQ caused significant increase in the thiobarbituric acid reactive substances (TBARS) level; (4) an increase in SOD activity and a decrease in catalase activity; and (5) a decrease in GST activity and GSH level. We have also found that quinones possessing a higher number of chlorine atoms on the quinone ring display a greater activity and that DH-LA is an effective protective agent as it diminishes PCB quinone-induced cellular oxidative stress. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Induction of Apoptosis by Ethanolic Extract of Corchorus olitorius Leaf in Human Hepatocellular Carcinoma (HepG2 Cells via a Mitochondria-Dependent Pathway

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    Shih-Fang Tsang

    2012-08-01

    Full Text Available Corchorus olitorius L., is a culinary and medicinal herb, widely used as a vegetable in several countries in Asia. Many studies have shown that C. olitorius contains several antioxidants and exhibits anti-inflammatory and anti-proliferative activities in various in vitro and in vivo settings. Recently, C. olitorius has been approved for its antitumor activity; however, the underlying molecular mechanisms remain unclear. The goal of this study was to investigate the effects of ethanol extract of C. olitorius (ECO on the growth of human hepatocellular carcinoma (HepG2 cells and gain some insights into the underlying mechanisms of its action. We found that HepG2 cells, treated with ECO for 24 h at a concentration higher than 12.5 μg/mL, displayed a strong reduction in cell viability, whereas normal FL83B hepatocytes were not affected. DNA fragmentation and nuclear condensation were evidenced by the increased subG1 population of ECO-treated HepG2 cells. ECO triggered the activation of procaspases-3 and -9 and caused the cleavage of downstream substrate, poly ADP-ribose polymerase (PARP, followed by down-regulation of the inhibitor of caspase-activated DNase (ICAD signaling. Moreover, the increased release of cytochrome c from mitochondria with decreased membrane potential demonstrated the apoptosis induced through the caspases cascade. Our findings indicated that ECO might be effective against hepatocellular carcinoma through induction of apoptosis via mitochondria-dependent pathway.

  7. AMPK activation ameliorates D-GalN/LPS-induced acute liver failure by upregulating Foxo3A to induce autophagy.

    Science.gov (United States)

    Liu, Yan-Min; Lv, Jun; Zeng, Qing-Lei; Shen, Shen; Xing, Ji-Yuan; Zhang, Ying-Ying; Zhang, Zhi-Hao; Yu, Zu-Jiang

    2017-09-15

    Acute liver failure (ALF) is an uncommon but serious disease still carrying a high mortality. This study aimed to investigate the mechanism of AMPK on D-GalN/LPS-induced ALF. In this study, we utilized intraperitoneal injection of D-GalN/LPS to induce ALF model, and analyzed the expression of AMPK, inflammatory cytokines (TNF-α, IL-1β and IL-6), Foxo3A and autophagy-related genes (Atg-5, Beclin-1, Atg-7) by real-time quantitative polymerase chain reaction (RT-PCR) in liver tissue. We also examined the level of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in serum of ALF mice. AMPK activation and inhibition of autophagy were induced by AICAR and 3-MA, respectively. Silence and overexpression of Foxo3A were performed by si-Foxo3A and pcDNA-Foxo3A, respectively. Lastly, the BMDM-conditioned medium (BMDM-CM) derived from BMDMs treated with AICAR and LPS were used to explore the effect of AMPK and Foxo3A on hepatocytes. The expression of AMPK was decreased in liver tissue and the level of ALT and AST were increased in serum of D-GalN/LPS-induced ALF mice. AMPK activation ameliorated ALF by inhibiting inflammation (downregulated TNF-α, IL-1β and IL-6 expression), activating autophagy (increased Atg-5, Beclin-1 and Atg-7 expression) and upregulating Foxo3A expression. Silence of Foxo3A decreased AMPK-activated autophagy, but overexpressing Foxo3A attenuated liver failure by activating autophagy. In addition, AMPK activation alleviated liver failure in vitro. Thus, AMPK/Foxo3A/autophagy pathway may be an effective treatment approach to ameliorate ALF. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Cadmium, lead, and arsenic contamination in paddy soils of a mining area and their exposure effects on human HEPG2 and keratinocyte cell-lines.

    Science.gov (United States)

    Xue, Shengguo; Shi, Lizheng; Wu, Chuan; Wu, Hui; Qin, Yanyan; Pan, Weisong; Hartley, William; Cui, Mengqian

    2017-07-01

    A mining district in south China shows significant metal(loid) contamination in paddy fields. In the soils, average Pb, Cd and As concentrations were 460.1, 11.7 and 35.1mgkg-1 respectively, which were higher than the environmental quality standard for agricultural soils in China (GB15618-1995) and UK Clea Soil Guideline Value. The average contents of Pb, Cd and As in rice were 5.24, 1.1 and 0.7mgkg-1 respectively, which were about 25, 4.5 or 2.5 times greater than the limit values of the maximum safe contaminant concentration standard in food of China (GB 2762-2012), and about 25, 10 or 1 times greater than the limit values of FAO/WHO standard. The elevated contents of Pb, Cd and As detected in soils around the factories, indicated that their spatial distribution was influenced by anthropogenic activity, while greater concentrations of Cd in rice appeared in the northwest region of the factories, indicating that the spatial distribution of heavy metals was also affected by natural factors. As human exposure around mining districts is mainly through oral intake of food and dermal contact, the effects of these metals on the viability and MT protein of HepG2 and KERTr cells were investigated. The cell viability decreased with increasing metal concentrations. Co-exposure to heavy metals (Pb+Cd) increased the metals (Pb or Cd)-mediated MT protein induction in both human HepG2 and KERTr cells. Increased levels of MT protein will lead to greater risk of carcinogenic manifestations, and it is likely that chronic exposure to metals may increase the risk to human health. Nevertheless, when co-exposure to two or more metals occur (such as As+Pb), they may have an antagonistic effect thus reducing the toxic effects of each other. Metal contaminations in paddy soils and rice were influenced by anthropogenic activity; metal co-exposure induced MT protein in human cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Caffeine attenuates lipid accumulation via activation of AMP-activated protein kinase signaling pathway in HepG2 cells.

    Science.gov (United States)

    Quan, Hai Yan; Kim, Do Yeon; Chung, Sung Hyun

    2013-04-01

    The main purpose of this study is to examine the effect of caffeine on lipid accumulation in human hepatoma HepG2 cells. Significant decreases in the accumulation of hepatic lipids, such as triglyceride (TG), and cholesterol were observed when HepG2 cells were treated with caffeine as indicated. Caffeine decreased the mRNA level of lipogenesis-associated genes (SREBP1c, SREBP2, FAS, SCD1, HMGR and LDLR). In contrast, mRNA level of CD36, which is responsible for lipid uptake and catabolism, was increased. Next, the effect of caffeine on AMP-activated protein kinase (AMPK) signaling pathway was examined. Phosphorylation of AMPK and acetyl-CoA carboxylase were evidently increased when the cells were treated with caffeine as indicated for 24 h. These effects were all reversed in the presence of compound C, an AMPK inhibitor. In summary, these data indicate that caffeine effectively depleted TG and cholesterol levels by inhibition of lipogenesis and stimulation of lipolysis through modulating AMPK-SREBP signaling pathways.

  10. Effervescent Granules Prepared Using Eucommia ulmoides Oliv. and Moso Bamboo Leaves: Hypoglycemic Activity in HepG2 Cells

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    Xiang-Zhou Li

    2016-01-01

    Full Text Available Eucommia ulmoides Oliv. (E. ulmoides Oliv. and moso bamboo (Phyllostachys pubescens leaves are used as folk medicines in central-western China to treat diabetes. To investigate the hypoglycemic activity of the effervescent granules prepared using E. ulmoides Oliv. and moso bamboo leaves (EBEG in HepG2 cells, EBEG were prepared with 5% of each of polysaccharides and chlorogenic acids from moso bamboo and E. ulmoides Oliv. leaves, respectively. HepG2 cells cultured in a high-glucose medium were classified into different groups. The results displayed EBEG-treated cells showed better glucose utilization than the negative controls; thus, the hypoglycemic effect of EBEG was much greater than that of granules prepared using either component alone, thereby indicating that this effect was due to a synergistic action of the components. Further, glucose consumption levels in the cells treated with EBEG (156.35% at 200 μg/mL and the positive controls (metformin, 162.29%; insulin, 161.52% were similar. Thus, EBEG exhibited good potential for use as a natural antidiabetic agent. The hypoglycemic effect of EBEG could be due to the synergistic action of polysaccharides from the moso bamboo leaves and chlorogenic acids from E. ulmoides Oliv. leaves via the inhibition of alpha-glucosidase and glucose-6-phosphate displacement enzyme.

  11. Screening of α-Tocopherol Transfer Protein Sensitive Genes in Human Hepatoma Cells (HepG2

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    Yang-Hua Qu

    2016-06-01

    Full Text Available α-Tocopherol transfer protein (α-TTP is a ~32 kDa protein expressed mainly in hepatocytes. The major function of the protein is to bind specifically to α-tocopherol and, together, the complex transfers from late lysosomes to the cell membrane. A previous study indicated that some factors might be required in the transferring process. However, there is little information available about the potential transferring factors. In addition, there remains much to learn about other physiological processes which α-TTP might participate in. Thus, in this study a human α-TTP eukaryotic expression vector was successfully constructed and expressed in human hepatoma cells (HepG2. The sensitive genes related to α-TTP were then screened by microarray technology. Results showed that expression of the vector in HepG2 cells led to the identification of 323 genes showing differential expression. The differentially expressed transcripts were divided into four main categories, including (1 cell inflammation; (2 cell cycle and cell apoptosis; (3 cell signaling and gene regulation; and (4 cellular movement. A few cellular movement related transcripts were selected and verified by quantitative real-time PCR. Expressions of some were significantly increased in α-TTP-expressed group, which indicated that these factors were likely to play a role in the transferring process.

  12. RIP-1/c-FLIPL Induce Hepatic Cancer Cell Apoptosis Through Regulating Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand (TRAIL).

    Science.gov (United States)

    Sun, Jichun; Yu, Xiao; Wang, Changfa; Yu, Can; Li, Zhiqiang; Nie, Wanpin; Xu, Xundi; Miao, Xiongying; Jin, Xiaoxin

    2017-03-08

    BACKGROUND Almost all hepatic cancer cells have resistance to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis. c-FLIPL and RIP-1 are apoptotic negative regulatory factors. This study investigated the role of c-FLIPL and RIP-1 in hepatic cancer cell resistance to TRAIL-induced apoptosis. MATERIAL AND METHODS HepG2 cells were treated by TRAIL, RIP-1 siRNA, and/or BY11-7082. Cell viability was detected by MTT assay. Cell apoptosis was tested by flow cytometry. DISC component proteins, RIP-1, and p-p65 were measured by Western blot. Caspase-8 and caspase-3 were determined by spectrophotometry. RESULTS Single TRAIL treatment showed no significant impact on cell proliferation and apoptosis. HepG2 cells expressed high levels of RIP1 and c-FLIPL, while a high concentration of TRAIL upregulated RIP-1 and c-FLIPL expression but not DR4 and DR5. Single TRAIL treatment did not obviously activate caspase-8 and caspase-3. RIP-1 or c-FLIPL siRNA markedly induced cell apoptosis and enhanced caspase-8 and caspase-3 activities. Combined transfection obviously increased apoptotic cells. TRAIL markedly upregulated RIP-1 expression and enhanced p-p65 protein. Downregulating RIP-1 and/or BAY11-7082 significantly reduced NF-kB transcriptional activity, blocked cells in G0/G1 phase, weakened proliferation, elevated caspase-8 and caspase-3 activities, and promoted cell apoptosis. CONCLUSIONS TRAIL can enhance RIP1 and c-FLIPL expression in HepG2 cells. High expression of RIP1 and c-FLIPL is an important reason for TRAIL resistance. Downregulation of RIP1 and c-FLIPL can relieve caspase-8 suppression, activate caspase-3, and promote cell apoptosis. TRAIL mediates apoptosis resistance through upregulating RIP-1 expression, enhancing NF-kB transcriptional activity, and weakening caspase activity.

  13. Up-Regulation of Claudin-6 in the Distal Lung Impacts Secondhand Smoke-Induced Inflammation

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    Joshua B. Lewis

    2016-10-01

    Full Text Available It has long been understood that increased epithelial permeability contributes to inflammation observed in many respiratory diseases. Recently, evidence has revealed that environmental exposure to noxious material such as cigarette smoke reduces tight junction barrier integrity, thus enhancing inflammatory conditions. Claudin-6 (Cldn6 is a tetraspanin transmembrane protein found within the tight junctional complex and is implicated in maintaining lung epithelial barriers. To test the hypothesis that increased Cldn6 ameliorates inflammation at the respiratory barrier, we utilized the Tet-On inducible transgenic system to conditionally over-express Clnd6 in the distal lung. Cldn6 transgenic (TG and control mice were continuously provided doxycycline from postnatal day (PN 30 until euthanasia date at PN90. A subset of Cldn6 TG and control mice were also subjected to daily secondhand tobacco smoke (SHS via a nose only inhalation system from PN30-90 and compared to room air (RA controls. Animals were euthanized on PN90 and lungs were harvested for histological and molecular characterization. Bronchoalveolar lavage fluid (BALF was procured for the assessment of inflammatory cells and molecules. Quantitative RT-PCR and immunoblotting revealed increased Cldn6 expression in TG vs. control animals and SHS decreased Cldn6 expression regardless of genetic up-regulation. Histological evaluations revealed no adverse pulmonary remodeling via Hematoxylin and Eosin (H&E staining or any qualitative alterations in the abundance of type II pneumocytes or proximal non-ciliated epithelial cells via staining for cell specific propeptide of Surfactant Protein-C (proSP-C or Club Cell Secretory Protein (CCSP, respectively. Immunoblotting and qRT-PCR confirmed the differential expression of Cldn6 and the pro-inflammatory cytokines TNF-α and IL-1β. As a general theme, inflammation induced by SHS exposure was influenced by the availability of Cldn6. These data reveal

  14. Up-Regulation of Claudin-6 in the Distal Lung Impacts Secondhand Smoke-Induced Inflammation.

    Science.gov (United States)

    Lewis, Joshua B; Milner, Dallin C; Lewis, Adam L; Dunaway, Todd M; Egbert, Kaleb M; Albright, Scott C; Merrell, Brigham J; Monson, Troy D; Broberg, Dallin S; Gassman, Jason R; Thomas, Daniel B; Arroyo, Juan A; Reynolds, Paul R

    2016-10-17

    It has long been understood that increased epithelial permeability contributes to inflammation observed in many respiratory diseases. Recently, evidence has revealed that environmental exposure to noxious material such as cigarette smoke reduces tight junction barrier integrity, thus enhancing inflammatory conditions. Claudin-6 (Cldn6) is a tetraspanin transmembrane protein found within the tight junctional complex and is implicated in maintaining lung epithelial barriers. To test the hypothesis that increased Cldn6 ameliorates inflammation at the respiratory barrier, we utilized the Tet-On inducible transgenic system to conditionally over-express Clnd6 in the distal lung. Cldn6 transgenic (TG) and control mice were continuously provided doxycycline from postnatal day (PN) 30 until euthanasia date at PN90. A subset of Cldn6 TG and control mice were also subjected to daily secondhand tobacco smoke (SHS) via a nose only inhalation system from PN30-90 and compared to room air (RA) controls. Animals were euthanized on PN90 and lungs were harvested for histological and molecular characterization. Bronchoalveolar lavage fluid (BALF) was procured for the assessment of inflammatory cells and molecules. Quantitative RT-PCR and immunoblotting revealed increased Cldn6 expression in TG vs. control animals and SHS decreased Cldn6 expression regardless of genetic up-regulation. Histological evaluations revealed no adverse pulmonary remodeling via Hematoxylin and Eosin (H&E) staining or any qualitative alterations in the abundance of type II pneumocytes or proximal non-ciliated epithelial cells via staining for cell specific propeptide of Surfactant Protein-C (proSP-C) or Club Cell Secretory Protein (CCSP), respectively. Immunoblotting and qRT-PCR confirmed the differential expression of Cldn6 and the pro-inflammatory cytokines TNF-α and IL-1β. As a general theme, inflammation induced by SHS exposure was influenced by the availability of Cldn6. These data reveal captivating

  15. Lupin Peptides Modulate the Protein-Protein Interaction of PCSK9 with the Low Density Lipoprotein Receptor in HepG2 Cells

    Science.gov (United States)

    Lammi, Carmen; Zanoni, Chiara; Aiello, Gilda; Arnoldi, Anna; Grazioso, Giovanni

    2016-07-01

    Proprotein convertase subtilisin/kexin type 9 (PCSK9) has been recently identified as a new useful target for hypercholesterolemia treatment. This work demonstrates that natural peptides, deriving from the hydrolysis of lupin protein and absorbable at intestinal level, are able to inhibit the protein-protein interaction between PCSK9 and the low density lipoprotein receptor (LDLR). In order to sort out the best potential inhibitors among these peptides, a refined in silico model of the PCSK9/LDLR interaction was developed. Docking, molecular dynamics (MD) simulations and peptide binding energy estimations, by MM-GBSA approach, permitted to select the two best candidates among tested peptides that were synthesized and evaluated for their inhibitory activity. The most active was P5 that induced a concentration dependent inhibition of the PCSK9-LDLR binding, with an IC50 value equal to 1.6 ± 0.33 μM. Tested at a 10 μM concentration, this peptide increased by 66 ± 21.4% the ability of HepG2 cells to take up LDL from the extracellular environment.

  16. Evaluation of Synergetic Anticancer Activity of Berberine and Curcumin on Different Models of A549, Hep-G2, MCF-7, Jurkat, and K562 Cell Lines

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    Acharya Balakrishna

    2015-01-01

    Full Text Available Ayurvedic system of medicine is using Berberis aristata and Curcuma longa herbs to treat different diseases including cancer. The study was performed to evaluate the synergetic anticancer activity of Berberine and Curcumin by estimating the inhibition of the cell proliferation by cytotoxicity assay using MTT method on specified human cell lines (A549, Hep-G2, MCF-7, Jurkat, and K562. All the cells were harvested from the culture and seeded in the 96-well assay plates at seeding density of 2.0 × 104 cells/well and were incubated for 24 hours. Test items Berberine with Curcumin (1 : 1, Curcumin 95% pure, and Berberine 95% pure were exposed at the concentrations of 1.25, 0.001, and 0.5 mg/mL, respectively, and incubated for a period of 48 hours followed by dispensing MTT solution (5 mg/mL. The cells were incubated at 37 ± 1°C for 4 hours followed by addition of DMSO for dissolving the formazan crystals and absorbance was read at 570 nm. Separate wells were prepared for positive control, controls (only medium with cells, and blank (only medium. The results had proven the synergetic anticancer activity of Berberine with Curcumin inducing cell death greater percentage of >77% when compared to pure curcumin with <54% and pure Berberine with <45% on average on all cell line models.

  17. Synergistic Hepatoprotective and Antioxidant Effect of Artichoke, Fig, Mulberry Herbal Mixture on HepG2 Cells and their Metabolic Profiling Using NMR Coupled with Chemometrics.

    Science.gov (United States)

    Youssef, Fadia S; Labib, Rola M; Eldahshan, Omayma A; Singab, Abdel Nasser B

    2017-09-12

    The edible plants have long been reported to possess a lot of biological activities. Herein, the hepatoprotective and the antioxidant activity of the aqueous infusion of the edible parts of Cynara cardunculus, Ficus carica and Morus nigra and their herbal mixture (CFM) was investigated in vitro using CCl4 induced damage in HepG2 cells. The highest amelioration was observed via the consumption of CFM at 1 mg/ml showing 47.00, 37.09% decline in AST (Aspartate Transaminase) and ALT (Alanine Transaminase) and 77.32 and 101.02% increase in GSH (Reduced Glutathione) and SOD (Superoxide dismutase) comparable to CCl4 treated cells. Metabolic profiling of their aqueous infusions was done using nuclear magnetic resonance spectroscopic experiments coupled with chemometrics particularly HCA (Hierarchical Cluster Analysis) and PCA (Principal Component Analysis). The structural closeness of the various metabolites existing in black berry and the mixture as reflected in the PCA score plot and HCA processed from the (1) H NMR spectral data could eventually explained the close values in their biological behavior. For fig and artichoke the existence of different phenolic metabolites that act synergistically could greatly interpret their potent biological behavior. Thus, it can be concluded that a herbal mixture composed of black berry, artichoke and fig could afford an excellent natural candidate to combat oxidative stress and counteract hepatic toxins owing to its phenolic compounds. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  18. Effects of Elaidic Acid on Lipid Metabolism in HepG2 Cells, Investigated by an Integrated Approach of Lipidomics, Transcriptomics and Proteomics

    DEFF Research Database (Denmark)

    Vendel Nielsen, Lone; Hansen, Toke Peter Krogager; Young, Clifford

    2013-01-01

    Trans fatty acid consumption in the human diet can cause adverse health effects, such as cardiovascular disease, which is associated with higher total cholesterol, a higher low density lipoprotein-cholesterol level and a decreased high density lipoprotein-cholesterol level. The aim of the study w...... occurred at the phospholipid level. Our findings contribute to the explanation on how trans fatty acids from the diet can cause modifications in plasma cholesterol levels by inducing abundance changes in several hepatic proteins and the hepatic membrane composition.......Trans fatty acid consumption in the human diet can cause adverse health effects, such as cardiovascular disease, which is associated with higher total cholesterol, a higher low density lipoprotein-cholesterol level and a decreased high density lipoprotein-cholesterol level. The aim of the study...... was to elucidate the hepatic response to the most abundant trans fatty acid in the human diet, elaidic acid, to help explain clinical findings on the relationship between trans fatty acids and cardiovascular disease. The human HepG2 cell line was used as a model to investigate the hepatic response to elaidic acid...

  19. Gas6 induces cancer cell migration and epithelial–mesenchymal transition through upregulation of MAPK and Slug

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yunhee [Department of Chemistry, Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Immunotherapy Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon (Korea, Republic of); Lee, Mira [Immunotherapy Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon (Korea, Republic of); Kim, Semi, E-mail: semikim@kribb.re.kr [Department of Chemistry, Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Immunotherapy Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon (Korea, Republic of)

    2013-04-26

    Highlights: •We investigated the molecular mechanisms underlying Gas6-mediated cancer cell migration. •Gas6 treatment and subsequent Axl activation induce cell migration and EMT via upregulation of Slug. •Slug expression mediated by Gas6 is mainly through c-Jun and ATF-2 in an ERK1/2 and JNK-dependent manner. •The Gas6/Axl-Slug axis may be exploited as a target for anti-cancer metastasis therapy. -- Abstract: Binding of Gas6 to Axl (Gas6/Axl axis) alters cellular functions, including migration, invasion, proliferation, and survival. However, the molecular mechanisms underlying Gas6-mediated cell migration remain poorly understood. In this study, we found that Gas6 induced the activation of JNK and ERK1/2 signaling in cancer cells expressing Axl, resulting in the phosphorylation of activator protein-1 (AP-1) transcription factors c-Jun and ATF-2, and induction of Slug. Depletion of c-Jun or ATF-2 by siRNA attenuated the Gas6-induced expression of Slug. Slug expression was required for cell migration and E-cadherin reduction/vimentin induction induced by Gas6. These results suggest that Gas6 induced cell migration via Slug upregulation in JNK- and ERK1/2-dependent mechanisms. These data provide an important insight into the molecular mechanisms mediating Gas6-induced cell migration.

  20. Hesperidin protects against cyclophosphamide-induced hepatotoxicity by upregulation of PPARγ and abrogation of oxidative stress and inflammation.

    Science.gov (United States)

    Mahmoud, Ayman M

    2014-09-01

    The most important reason for the non-approval and withdrawal of drugs by the Food and Drug Administration is hepatotoxicity. Therefore, this study was undertaken to evaluate the protective effects of hesperidin against cyclophosphamide (CYP)-induced hepatotoxicity in Wistar rats. The rats received a single intraperitoneal dose of CYP of 200 mg/kg body mass, followed by treatment with hesperidin, orally, at doses of 25 and 50 mg/kg for 11 consecutive days. CYP induced hepatic damage, as evidenced by the significantly elevated levels of serum pro-inflammatory cytokines, serum transaminases, liver lipid peroxidation, and nitric oxide. As a consequence, there was reduced glutathione content, and the activities of the antioxidant enzymes superoxide dismutase, catalase, and glutathione peroxidase, were markedly reduced. In addition, CYP administration induced a considerable downregulation of peroxisome proliferator activated receptor gamma (PPARγ) and upregulation of nuclear factor-kappa B (NF-κB) and inducible nitric oxide synthase (iNOS) mRNA expression. Hesperidin, in a dose-dependent manner, rejuvenated the altered markers to an almost normal state. In conclusion, hesperidin showed a potent protective effect against CYP-induced oxidative stress and inflammation leading to hepatotoxicity. The study suggests that hesperidin exerts its protective effect against CYP-induced hepatotoxicity through upregulation of hepatic PPARγ expression and abrogation of inflammation and oxidative stress.

  1. High glucose-induced apoptosis in human coronary artery endothelial cells involves up-regulation of death receptors

    Directory of Open Access Journals (Sweden)

    Yamamoto Seiji

    2011-08-01

    Full Text Available Abstract Background High glucose can induce apoptosis in vascular endothelial cells, which may contribute to the development of vascular complications in diabetes. We evaluated the role of the death receptor pathway of apoptotic signaling in high glucose-induced apoptosis in human coronary artery endothelial cells (HCAECs. Methods HCAECs were treated with media containing 5.6, 11.1, and 16.7 mM of glucose for 24 h in the presence or absence of tumor necrosis factor (TNF-α. For detection of apoptosis, DNA fragmentation assay was used. HCAEC expression of death receptors were analyzed by the PCR and flow cytometry methods. Also, using immunohistochemical techniques, coronary expression of death receptors was assessed in streptozotocin-nicotinamide-induced type 2 diabetic mice. Results Exposure of HCAECs to high glucose resulted in a significant increase in TNF-R1 and Fas expression, compared with normal glucose. High glucose increased TNF-α production by HCAECs and exogenous TNF-α up-regulated TNF-R1 and Fas expression in HCAECs. High glucose-induced up-regulation of TNF-R1 and Fas expression was undetectable in the presence of TNF-α. Treatment with TNF-R1 neutralizing peptides significantly inhibited high glucose-induced endothelial cell apoptosis. Type 2 diabetic mice displayed appreciable expression of TNF-R1 and Fas in coronary vessels. Conclusions In association with increased TNF-α levels, the death receptors, TNF-R1 and Fas, are up-regulated in HCAECs under high glucose conditions, which could in turn play a role in high glucose-induced endothelial cell apoptosis.

  2. Subarachnoid hemorrhage-induced upregulation of the 5-HT1B receptor in cerebral arteries in rats

    DEFF Research Database (Denmark)

    Hansen-Schwartz, Jacob; Hoel, Natalie Løvland; Xu, Cang-Bao

    2003-01-01

    OBJECT: Cerebral vasospasm following subarachnoid hemorrhage (SAH) leads to reduced blood flow in the brain. Inspired by organ culture-induced changes in the receptor phenotype of cerebral arteries, the authors investigated possible changes in the 5-hydroxytryptamine (HT) receptor phenotype after...... to the actual development of cerebral vasospasm. Insight into the mechanism of upregulation may provide new targets for developing specific treatment against cerebral vasospasm....... experimental SAH. METHODS: Experimental SAH was induced in rats by using an autologous prechiasmatic injection of arterial blood. Two days later, the middle cerebral artery (MCA), posterior communicating artery (PCoA), and basilar artery (BA) were harvested and examined functionally with the aid of a sensitive...

  3. Acute hypoxia induces upregulation of microRNA-210 expression in glioblastoma spheroids

    DEFF Research Database (Denmark)

    Rosenberg, Tine Agerbo; Thomassen, Mads; Jensen, Stine Skov

    2015-01-01

    & METHODS: Glioblastoma spheroid cultures were grown in either 2 or 21% oxygen. Subsequently, miRNA profiling was performed and expression of ten stem cell markers was examined. RESULTS: MiRNA-210 was significantly upregulated in hypoxia in patient-derived spheroids. The stem cell markers displayed...

  4. Allergic contact dermatitis induces upregulation of identical microRNAs in humans and mice

    DEFF Research Database (Denmark)

    Vennegaard, Marie T; Bonefeld, Charlotte M; Hagedorn, Peter

    2012-01-01

    MicroRNAs are short, endogenous RNA molecules that can bind to parts of target mRNAs, thus inhibiting their translation and causing accelerated turnover or degradation of transcripts, thereby regulating gene expression. Several microRNAs have been found to be upregulated in atopic dermatitis and ...

  5. Oxidation of fatty acid may be enhanced by a combination of pomegranate fruit phytochemicals and acetic acid in HepG2 cells

    Science.gov (United States)

    Kim, Ji Yeon; Ok, Elly; Kim, You Jin; Choi, Kyoung-Sook

    2013-01-01

    We investigated whether the combination of phytochemicals and acetic acid in the form of fruit vinegar provides an additive effect on changes of mRNA levels related to fatty acid oxidation in human hepatocyte (HepG2). Among the seven fruit vinegars (Rubuscoreanus, Opuntia, blueberry, cherry, red ginseng, mulberry, and pomegranate) studied, treatment of HepG2 with pomegranate vinegar (PV) at concentrations containing 1 mM acetic acid showed the highest in vitro potentiating effect on the mRNA expression levels of peroxisome proliferator-activated receptor α, carnitinepalmitoyl transferase-1, and acyl-CoA oxidase compared to the control group (P punicalagin B, ellagic acid, and two unidentified compounds) responsible for altered gene expression in HepG2 cells treated with PV as compared with the others. Further investigations are warranted to determine if drinking PV beverages may help to maintain a healthy body weight in overweight subjects. PMID:23766874

  6. Oxidation of fatty acid may be enhanced by a combination of pomegranate fruit phytochemicals and acetic acid in HepG2 cells.

    Science.gov (United States)

    Kim, Ji Yeon; Ok, Elly; Kim, You Jin; Choi, Kyoung-Sook; Kwon, Oran

    2013-06-01

    We investigated whether the combination of phytochemicals and acetic acid in the form of fruit vinegar provides an additive effect on changes of mRNA levels related to fatty acid oxidation in human hepatocyte (HepG2). Among the seven fruit vinegars (Rubuscoreanus, Opuntia, blueberry, cherry, red ginseng, mulberry, and pomegranate) studied, treatment of HepG2 with pomegranate vinegar (PV) at concentrations containing 1 mM acetic acid showed the highest in vitro potentiating effect on the mRNA expression levels of peroxisome proliferator-activated receptor α, carnitinepalmitoyl transferase-1, and acyl-CoA oxidase compared to the control group (P acid, and two unidentified compounds) responsible for altered gene expression in HepG2 cells treated with PV as compared with the others. Further investigations are warranted to determine if drinking PV beverages may help to maintain a healthy body weight in overweight subjects.

  7. Melatonin enhances arsenic trioxide-induced cell death via sustained upregulation of Redd1 expression in breast cancer cells.

    Science.gov (United States)

    Yun, Sun-Mi; Woo, Sang Hyeok; Oh, Sang Taek; Hong, Sung-Eun; Choe, Tae-Boo; Ye, Sang-Kyu; Kim, Eun-Kyu; Seong, Min Ki; Kim, Hyun-A; Noh, Woo Chul; Lee, Jin Kyung; Jin, Hyeon-Ok; Lee, Yun-Han; Park, In-Chul

    2016-02-15

    Melatonin is implicated in various physiological functions, including anticancer activity. However, the mechanism(s) of its anticancer activity is not well understood. In the present study, we investigated the combined effects of melatonin and arsenic trioxide (ATO) on cell death in human breast cancer cells. Melatonin enhanced the ATO-induced apoptotic cell death via changes in the protein levels of Survivin, Bcl-2, and Bax, thus affecting cytochrome c release from the mitochondria to the cytosol. Interestingly, we found that the cell death induced by co-treatment with melatonin and ATO was mediated by sustained upregulation of Redd1, which was associated with increased production of reactive oxygen species (ROS). Combined treatment with melatonin and ATO induced the phosphorylation of JNK and p38 MAP kinase downstream from Redd1 expression. Rapamycin and S6K1 siRNA enhanced, while activation of mTORC1 by transfection with TSC2 siRNA suppressed the cell death induced by melatonin and ATO treatment. Taken together, our findings suggest that melatonin enhances ATO-induced apoptotic cell death via sustained upregulation of Redd1 expression and inhibition of mTORC1 upstream of the activation of the p38/JNK pathways in human breast cancer cells. Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  8. Studies on Cytotoxic Activity against HepG-2 Cells of Naphthoquinones from Green Walnut Husks of Juglans mandshurica Maxim

    Directory of Open Access Journals (Sweden)

    Yuanyuan Zhou

    2015-08-01

    Full Text Available Twenty-seven naphthoquinones and their derivatives, including four new naphthalenyl glucosides and twenty-three known compounds, were isolated from green walnut husks, which came from Juglans mandshurica Maxim. The structures of four new naphthalenyl glucosides were elucidated based on extensive spectroscopic analyses. All of these compounds were evaluated for their cytotoxic activities against the growth of human cancer cells lines HepG-2 by MTT [3-(4,5-dimethylthiazo l-2-yl-2,5 diphenyl tetrazolium bromide] assay. The results were shown that most naphthoquinones in an aglycone form exhibited better cytotoxicity in vitro than naphthalenyl glucosides with IC50 values in the range of 7.33–88.23 μM. Meanwhile, preliminary structure-activity relationships for these compounds were discussed.

  9. The antioxidant activity of daidzein metabolites, O‑desmethylangolensin and equol, in HepG2 cells.

    Science.gov (United States)

    Choi, Eun Jeong; Kim, Gun-Hee

    2014-01-01

    Daidzein and its glycoside form daidzin, are known to have potential health benefits and are metabolized to O‑desmethylangolensin (O‑DMA) and equol following consumption. In the current study, the antioxidant activity and cytotoxicity of O‑DMA, equol, daidzein and daidzin was investigated and their effects on HepG2 human hepatocelluar carcinoma cells were compared. For cytotoxicity assays, lactose dehydrogenase (LDH) release and 3‑(4,5‑dimethylthiazol‑2‑yl)‑2,5‑diphenyltetrazolium bromide‑based cell viability, cells were exposed to various concentrations of each compound (5‑200 µM) for 24, 48 or 72 h. O‑DMA and equol did not affect LDH release, but higher concentrations (equol, as their effects were similar. These data suggested that O‑DMA and equol possess greater antioxidant properties compared with daidzein and may, thus, be beneficial for human health.

  10. OSBP-related protein 8 (ORP8) interacts with Homo sapiens sperm associated antigen 5 (SPAG5) and mediates oxysterol interference of HepG2 cell cycle

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Wenbin [Department of Biotechnology, Jinan University, Guangzhou 510632 (China); Zhou, You [Minerva Foundation Institute for Medical Research, Helsinki (Finland); Li, Jiwei [Department of Biotechnology, Jinan University, Guangzhou 510632 (China); Mysore, Raghavendra [Minerva Foundation Institute for Medical Research, Helsinki (Finland); Luo, Wei; Li, Shiqian [Department of Biotechnology, Jinan University, Guangzhou 510632 (China); Chang, Mau-Sun [Institute of Biochemical Sciences, National Taiwan University, No. 1, Taipei, Taiwan (China); Olkkonen, Vesa M. [Minerva Foundation Institute for Medical Research, Helsinki (Finland); Yan, Daoguang, E-mail: tydg@jnu.edu.cn [Department of Biotechnology, Jinan University, Guangzhou 510632 (China)

    2014-04-01

    We earlier identified OSBP-related protein 8 (ORP8) as an endoplasmic reticulum/nuclear envelope oxysterol-binding protein implicated in cellular lipid homeostasis, migration, and organization of the microtubule cytoskeleton. Here, a yeast two-hybrid screen identified Homo sapiens sperm associated antigen 5 (SPAG5)/Astrin as interaction partner of ORP8. The putative interaction was further confirmed by pull-down and co-immunoprecipitation assays. ORP8 did not colocalize with kinetochore-associated SPAG5 in mitotic HepG2 or HuH7 cells, but overexpressed ORP8 was capable of recruiting SPAG5 onto endoplasmic reticulum membranes in interphase cells. In our experiments, 25-hydroxycholesterol (25OHC) retarded the HepG2 cell cycle, causing accumulation in G2/M phase; ORP8 overexpression resulted in the same phenotype. Importantly, ORP8 knock-down dramatically inhibited the oxysterol effect on HepG2 cell cycle, suggesting a mediating role of ORP8. Furthermore, knock-down of SPAG5 significantly reduced the effects of both ORP8 overexpression and 25OHC on the cell cycle, placing SPAG5 downstream of the two cell-cycle interfering factors. Taken together, the present results suggest that ORP8 may via SPAG5 mediate oxysterol interference of the HepG2 cell cycle. - Highlights: • The oxysterol-binding protein ORP8 was found to interact with the mitotic regulator SPAG5/Astrin. • Treatment of HepG2 cells with 25-hydroxycholesterol caused cell cycle retardation in G2/M. • ORP8 overexpression caused a similar G2/M accumulation, and ORP8 knock-down reversed the 25-hydroxycholesterol effect. • Reduction of cellular of SPAG5/Astrin reversed the cell cycle effects of both 25-hydroxycholesterol and ORP8 overexpression. • Our results suggest that ORP8 mediates via SPAG5/Astrin the oxysterol interference of HepG2 cell cycle.

  11. The Vibrio cholerae Pst2 phosphate transport system is upregulated in biofilms and contributes to biofilm-induced hyperinfectivity.

    Science.gov (United States)

    Mudrak, Benjamin; Tamayo, Rita

    2012-05-01

    Vibrio cholerae is the causative agent of the deadly diarrheal disease cholera. As part of its life cycle, V. cholerae persists in marine environments, where it forms surface-attached communities commonly described as biofilms. Evidence indicates that these biofilms constitute the infectious form of the pathogen during outbreaks. Previous work has shown that biofilm-derived V. cholerae cells, even when fully dispersed from the biofilm matrix, are vastly more infectious than planktonic (free-living) cells. Here, we sought to identify factors that contribute to biofilm-induced hyperinfectivity in V. cholerae, and we present evidence for one aspect of the molecular basis of this phenotype. We identified proteins upregulated during growth in biofilms and determined their contributions to the hyperinfectivity phenotype. We found that PstS2, the periplasmic component of the Pst2 phosphate uptake system, was enriched in biofilms. Another gene in the pst2 locus was transcriptionally upregulated in biofilms. Using the infant mouse model, we found that mutation of two pst2 components resulted in impaired colonization. Importantly, deletion of the Pst2 inner membrane complex caused a greater colonization defect after growth in a biofilm compared to shaking culture. Based on these data, we propose that V. cholerae cells in biofilms upregulate the Pst2 system and therefore gain an advantage upon entry into the host. Further characterization of factors contributing to biofilm-induced hyperinfectivity in V. cholerae will improve our understanding of the transmission of the bacteria from natural aquatic habitats to the human host.

  12. Structure of Sphingolipids From Sea Cucumber Cucumaria frondosa and Structure-Specific Cytotoxicity Against Human HepG2 Cells.

    Science.gov (United States)

    Jia, Zicai; Song, Yu; Tao, Suyuan; Cong, Peixu; Wang, Xiaoxu; Xue, Changhu; Xu, Jie

    2016-03-01

    To investigate the relationship between structure and activity, three glucocerebroside series (CFC-1, CFC-2 and CFC-3), ceramides (CF-Cer) and long-chain bases (CF-LCB) of sea cucumber Cucumaria frondosa (C. frondosa) were isolated and evaluated in HepG2 cells. The molecular species of CFC-1, CFC-2 and CFC-3 and CF-Cer were identified using reversed-phase liquid chromatography with heated electrospray ionization coupled to high-resolution mass spectrometry (RPLC-HESI-HRMS), and determined on the basis of chemical and spectroscopic evidence: For the three glucocerebroside series, fatty acids (FA) were mainly saturated (18:0 and 22:0), monounsaturated (22:1, 23:1 and 24:1) and 2-hydroxyl FA (2-HFA) (23:1 h and 24:1 h), the structure of long-chain bases (LCB) were dihydroxy (d17:1, d18:1 and d18:2) and trihydroxy (t16:0 and t17:0), and the glycosylation was glucose; For CF-Cer, FA were primarily saturated (17:0) and monounsaturated (16:1 and 19:1), the structure of LCB were dihydroxy (d17:1 and d18:1), and trihydroxy (t16:0). The results of cell experiment indicated that all of three glucocerebroside series, CF-Cer and CF-LCB exhibited an inhibitory effects on cell proliferation. Moreover, CFC-3 was most effective in three glucocerebrosides to HepG-2 cell viability. The inhibition effect of CF-LCB was the strongest, and the inhibition effect of CF-Cer was much stronger than glucocerebrosides.

  13. Increase of Intracellular Cyclic AMP by PDE4 Inhibitors Affects HepG2 Cell Cycle Progression and Survival.

    Science.gov (United States)

    Massimi, Mara; Cardarelli, Silvia; Galli, Francesca; Giardi, Maria Federica; Ragusa, Federica; Panera, Nadia; Cinque, Benedetta; Cifone, Maria Grazia; Biagioni, Stefano; Giorgi, Mauro

    2017-06-01

    Type 4 cyclic nucleotide phosphodiesterases (PDE4) are major members of a superfamily of enzymes (PDE) involved in modulation of intracellular signaling mediated by cAMP. Broadly expressed in most human tissues and present in large amounts in the liver, PDEs have in the last decade been key therapeutic targets for several inflammatory diseases. Recently, a significant body of work has underscored their involvement in different kinds of cancer, but with no attention paid to liver cancer. The present study investigated the effects of two PDE4 inhibitors, rolipram and DC-TA-46, on the growth of human hepatoma HepG2 cells. Treatment with these inhibitors caused a marked increase of intracellular cAMP level and a dose- and time-dependent effect on cell growth. The concentrations of inhibitors that halved cell proliferation to about 50% were used for cell cycle experiments. Rolipram (10 μM) and DC-TA-46 (0.5 μM) produced a decrease of cyclin expression, in particular of cyclin A, as well as an increase in p21, p27 and p53, as evaluated by Western blot analysis. Changes in the intracellular localization of cyclin D1 were also observed after treatments. In addition, both inhibitors caused apoptosis, as demonstrated by an Annexin-V cytofluorimetric assay and analysis of caspase-3/7 activity. Results demonstrated that treatment with PDE4 inhibitors affected HepG2 cell cycle and survival, suggesting that they might be useful as potential adjuvant, chemotherapeutic or chemopreventive agents in hepatocellular carcinoma. J. Cell. Biochem. 118: 1401-1411, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  14. Proteomic analysis of the secretome of HepG2 cells indicates differential proteolytic processing after infection with dengue virus.

    Science.gov (United States)

    Caruso, Marjolly B; Trugilho, Monique R O; Higa, Luiza M; Teixeira-Ferreira, André S; Perales, Jonas; Da Poian, Andrea T; Zingali, Russolina B

    2017-01-16

    Secretome analysis can be described as a subset of proteomics studies consisting in the analysis of the molecules secreted by cells or tissues. Dengue virus (DENV) infection can lead to a broad spectrum of clinical manifestations, with the severe forms of the disease characterized by hemostasis abnormalities and liver injury. The hepatocytes are a relevant site of viral replication and a major source of plasma proteins. Until now, we had limited information on the small molecules secreted by hepatic cells after infection by DENV. In the present study, we analysed a fraction of the secretome of mock- and DENV-infected hepatic cells (HepG2 cells) containing molecules with <10kDa, using different proteomic approaches. We identified 175 proteins, with 57 detected only in the samples from mock-infected cells, 59 only in samples from DENV-infected cells, and 59 in both conditions. Most of the peptides identified were derived from proteins larger than 10kDa, suggesting a proteolytic processing of the secreted molecules. Using in silico analysis, we predicted consistent differences between the proteolytic processing occurring in mock and DENV-infected samples, raising, for the first time, the hypothesis that differential proteolysis of secreted molecules would be involved in the pathogenesis of dengue. Since the liver, one of the targets of DENV infection, is responsible for producing molecules involved in distinct biological processes, the identification of proteins and peptides secreted by hepatocytes after infection would help to a better understanding of the physiopathology of dengue. Proteomic analyses of molecules with <10kDa secreted by HepG2 cells after infection with DENV revealed differential proteolytic processing as an effect of DENV infection. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Ras induces experimental lung metastasis through up-regulation of RbAp46 to suppress RECK promoter activity.

    Science.gov (United States)

    Yeh, Hsuan-Heng; Tseng, Yu-Fen; Hsu, Yu-Chiao; Lan, Sheng-Hui; Wu, Shan-Ying; Raghavaraju, Giri; Cheng, Da-En; Lee, Ying-Ray; Chang, Tsuey-Yu; Chow, Nan-Haw; Hung, Wen-Chun; Liu, Hsiao-Sheng

    2015-03-25

    Mutant Ras plays multiple functions in tumorigenesis including tumor formation and metastasis. Reversion-inducing cysteine-rich protein with Kazal motifs (RECK), a metastasis inhibitor gene, suppresses matrix metalloproteinase (MMP) activity in the metastatic cascade. Clarifying the relationship between Ras and RECK and understanding the underlying molecular mechanism may lead to the development of better treatment for Ras-related tumors. Suppression subtractive hybridization PCR (SSH PCR) was conducted to identify Ha-ras (val12) up-regulated genes in bladder cancer cells. Stable cell lines of human breast cancer (MCF-7-ras) and mouse NIH3T3 fibroblasts (7-4) harboring the inducible Ha-ras (val12) oncogene, which could be induced by isopropylthio-β-D-galactoside (IPTG), were used to clarify the relationship between Ras and the up-regulated genes. Chromatin immunoprecipitation (ChIP) assay, DNA affinity precipitation assay (DAPA) and RECK reporter gene assay were utilized to confirm the complex formation and binding with promoters. Retinoblastoma binding protein-7 (RbAp46) was identified and confirmed as a Ha-ras (val12) up-regulated gene. RbAp46 could bind with histone deacetylase (HDAC1) and Sp1, followed by binding to RECK promoter at the Sp1 site resulting in repression of RECK expression. High expression of Ras protein accompanied with high RbAp46 and low RECK expression were detected in 75% (3/4) of the clinical bladder cancer tumor tissues compared to the adjacent normal parts. Ras induced RbAp46 expression increases invasion of the bladder cancer T24 cells and MMP-9 activity was increased, which was confirmed by specific lentiviral shRNAs inhibitors against Ras and RbAp46. Similarly, knockdown of RbAp46 expression in the stable NIH3T3 cells "7-4" by shRNA decreased Ras-related lung metastasis using a xenograft nude mice model. We confirmed that RbAp46 is a Ha-ras (val12) up-regulated gene and binds with HDAC1 and Sp1. Furthermore, RbAp46 binds to the RECK

  16. Mutant KRas-Induced Mitochondrial Oxidative Stress in Acinar Cells Upregulates EGFR Signaling to Drive Formation of Pancreatic Precancerous Lesions

    Directory of Open Access Journals (Sweden)

    Geou-Yarh Liou

    2016-03-01

    Full Text Available The development of pancreatic cancer requires the acquisition of oncogenic KRas mutations and upregulation of growth factor signaling, but the relationship between these is not well established. Here, we show that mutant KRas alters mitochondrial metabolism in pancreatic acinar cells, resulting in increased generation of mitochondrial reactive oxygen species (mROS. Mitochondrial ROS then drives the dedifferentiation of acinar cells to a duct-like progenitor phenotype and progression to PanIN. This is mediated via the ROS-receptive kinase protein kinase D1 and the transcription factors NF-κB1 and NF-κB2, which upregulate expression of the epidermal growth factor, its ligands, and their sheddase ADAM17. In vivo, interception of KRas-mediated generation of mROS reduced the formation of pre-neoplastic lesions. Hence, our data provide insight into how oncogenic KRas interacts with growth factor signaling to induce the formation of pancreatic cancer.

  17. TNF-α-induced NOD2 and RIP2 contribute to the up-regulation of cytokines induced by MDP in monocytic THP-1 cells.

    Science.gov (United States)

    Chen, Xiaobin; Xiao, Zhilin; Xie, Xiumei; Liu, Xueting; Jiang, Manli; Yuan, Chuang; Yang, Li; Hu, Jinyue

    2017-06-21

    Nucleotide-binding oligomerization domain containing 2 (NOD2)-induced signal transduction and cytokine production is regulated by a number of factors. However, the feedback effect of the pro-inflammatory TNF-α on NOD2-induced inflammation is not fully understood. In this study, we found unexpectedly that TNF-α up-regulated NOD2 ligand MDP-induced production of the CXC chemokines, including CXCL1, 2 and 8, and the pro-inflammatory cytokines, including IL-1β, IL-6 and TNF-α, in a dose-dependent manner at both mRNA and protein levels in monocytic THP-1 cells. Though TNF-α induced the up-regulation of ubiquitin-editing enzyme A20, an important negative regulator for Toll-like receptor- and NOD2-induced inflammatory responses, the over-expression of A20 by gene transfer did not reversed MDP-induced production of cytokines, suggested that A20 did not regulate the functions of NOD2 in THP-1 cells. Meanwhile, we found that TNF-α up-regulated NOD2 and its down-stream adaptor protein RIP2 at both mRNA and protein levels. MDP induced the activation of ERK, JNK, p38 and NF-κB, and TNF-α pre-treatment augmented this activation. The results from pharmacological inhibition assay showed that cytokine production was dependent on MAPK signaling. In addition, we found that the pre-treatment of THP-1 cells with MDP down-regulated the mRNA levels of cytokine induced by MDP re-treatment. MDP pre-treatment up-regulated NOD2, but down-regulated RIP2, and down-regulated NOD2 signal transduction induced by MDP re-stimulation. Taking together, these results suggested that TNF-α is a positive regulator for NOD2 functions via up-regulation of NOD2 and its signal adaptor RIP2, and TNF-α-induced A20 does not regulate MDP-induced inflammatory responses in THP-1 cells. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  18. A novel, soluble compound, C25, sensitizes to TRAIL-induced apoptosis through upregulation of DR5 expression.

    Science.gov (United States)

    James, Michael A; Seibel, William L; Kupert, Elena; Hu, Xiao X; Potharla, Vishwakanth Y; Anderson, Marshall W

    2015-06-01

    The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a potential therapeutic agent that induces apoptosis selectively in tumor cells. However, numerous solid tumor types are resistant to TRAIL. Sensitization to TRAIL has been an area of great research interest, but has met significant challenges because of poor bioavailability, half-life, and solubility of sensitizing compounds such as curcumin. Soluble, TRAIL-sensitizing compounds were screened on the basis of similarity to the redox-active substructure of curcumin and sensitization to TRAIL-induced apoptosis. We determined the effect of the lead compound, C25, in combination with TRAIL in human cancer cell lines using MTS proliferation assays, apoptosis assays, and western blotting. Short hairpin RNA knockdown of death receptor 5 (DR5) was performed to determine whether DR5 upregulation was required for TRAIL-mediated apoptosis. In-vivo efficacy was determined using human lung tumor xenograft models. C25 helped overcome TRAIL resistance by upregulating the expression of the TRAIL receptor DR5 and apoptosis in several tumor cell lines. Blockade of DR5 expression abrogated C25 sensitization to TRAIL, demonstrating the requirement for DR5 upregulation for C25-mediated potentiation of TRAIL-mediated apoptosis. The combination of C25 and TRAIL effectively inhibited tumorigenesis in vivo. This study demonstrates the synergistic efficacy of C25 in sensitization to TRAIL-induced apoptosis in multiple tumor cell types, including highly resistant lung and ovarian tumor cell lines. Furthermore, C25 was efficacious against tumor growth in vivo. Thus, C25 may be a potential therapeutic for cancer in combination with TRAIL or DR5 agonist therapy.

  19. ASPL-TFE3 Oncoprotein Regulates Cell Cycle Progression and Induces Cellular Senescence by Up-Regulating p21

    Directory of Open Access Journals (Sweden)

    Naoko Ishiguro

    2016-10-01

    Full Text Available Alveolar soft part sarcoma is an extremely rare soft tissue sarcoma with poor prognosis. It is characterized by the unbalanced recurrent chromosomal translocation der(17t(X;17(p11;q25, resulting in the generation of an ASPL-TFE3 fusion gene. ASPL-TFE3 oncoprotein functions as an aberrant transcriptional factor and is considered to play a crucial role in the tumorigenesis of alveolar soft part sarcoma. However, the underlying molecular mechanisms are poorly understood. In this study, we identified p21 (p21WAF1/CIP1 as a direct transcriptional target of ASPL-TFE3. Ectopic ASPL-TFE3 expression in 293 cells resulted in cell cycle arrest and significant increases in protein and mRNA levels of p21. ASPL-TFE3 activated p21 expression in a p53-independent manner through direct transcriptional interactions with the p21 promoter region. When ASPL-TFE3 was expressed in human bone marrow–derived mesenchymal stem cells in a tetracycline-inducible manner, we observed the up-regulation of p21 expression and the induction of senescence-associated β-galactosidase activity. Suppression of p21 significantly decreased the induction of ASPL-TFE3-mediated cellular senescence. Furthermore, ASPL-TFE3 expression in mesenchymal stem cells resulted in a significant up-regulation of proinflammatory cytokines associated with senescence-associated secretory phenotype (SASP. These results show that ASPL-TFE3 regulates cell cycle progression and induces cellular senescence by up-regulating p21 expression. In addition, our data suggest a potential mechanism by which ASPL-TFE3-induced senescence may play a role in tumorigenesis by inducing SASP, which could promote the protumorigenic microenvironment.

  20. Up-regulation of heme oxygenase-1 contributes to the amelioration of aluminum-induced oxidative stress in Medicago sativa.

    Science.gov (United States)

    Cui, Weiti; Zhang, Jing; Xuan, Wei; Xie, Yanjie

    2013-10-15

    In this report, pharmacological, histochemical and molecular approaches were used to investigate the effect of heme oxygenase-1 (HO-1) up-regulation on the alleviation of aluminum (Al)-induced oxidative stress in Medicago sativa. Exposure of alfalfa to AlCl3 (0-100 μM) resulted in a dose-dependent inhibition of root elongation as well as the enhancement of thiobarbituric acid reactive substances (TBARS) content. 1 and 10 μM (in particular) Al(3+) increased alfalfa HO-1 transcript or its protein level, and HO activity in comparison with the decreased changes in 100 μM Al-treated samples. After recuperation, however, TBARS levels in 1 and 10 μM Al-treated alfalfa roots returned to control values, which were accompanied with the higher levels of HO activity. Subsequently, exogenous CO, a byproduct of HO-1, could substitute for the cytoprotective effects of the up-regulation of HO-1 in alfalfa plants upon Al stress, which was confirmed by the alleviation of TBARS and Al accumulation, as well as the histochemical analysis of lipid peroxidation and loss of plasma membrane integrity. Theses results indicated that endogenous CO generated via heme degradation by HO-1 could contribute in a critical manner to its protective effects. Additionally, the pretreatments of butylated hydroxytoluene (BHT) and hemin, an inducer of HO-1, exhibited the similar cytoprotective roles in the alleviation of oxidative stress, both of which were impaired by the potent inhibitor of HO-1, zinc protoporphyrin IX (ZnPP). However, the Al-induced inhibition of root elongation was not influenced by CO, BHT and hemin, respectively. Together, the present results showed up-regulation of HO-1 expression could act as a mechanism of cell protection against oxidative stress induced by Al treatment. Copyright © 2013 Elsevier GmbH. All rights reserved.

  1. Astrocytes Upregulate Survival Genes in Tumor Cells and Induce Protection from Chemotherapy

    Directory of Open Access Journals (Sweden)

    Sun-Jin Kim

    2011-03-01

    Full Text Available In the United States, more than 40% of cancer patients develop brain metastasis. The median survival for untreated patients is 1 to 2 months, which may be extended to 6 months with conventional radiotherapy and chemotherapy. The growth and survival of metastasis depend on the interaction of tumor cells with host factors in the organ microenvironment. Brain metastases are surrounded and infiltrated by activated astrocytes and are highly resistant to chemotherapy. We report here that coculture of human breast cancer cells or lung cancer cells with murine astrocytes (but not murine fibroblasts led to the up-regulation of survival genes, including GSTA5, BCL2L1, and TWIST1, in the tumor cells. The degree of up-regulation directly correlated with increased resistance to all tested chemotherapeutic agents. We further show that the up-regulation of the survival genes and consequent resistance are dependent on the direct contact between the astrocytes and tumor cells through gap junctions and are therefore transient. Knocking down these genes with specific small interfering RNA rendered the tumor cells sensitive to chemotherapeutic agents. These data clearly demonstrate that host cells in the microenvironment influence the biologic behavior of tumor cells and reinforce the contention that the organ microenvironment must be taken into consideration during the design of therapy.

  2. [Statin reduced triglyceride level via activating peroxisome proliferator activated receptor α and upregulating apolipoprotein A5 in hypertriglyceridemic rats].

    Science.gov (United States)

    HUANG, Xian-sheng; ZHAO, Shui-ping; BAI, Lin; ZHANG, Qian; HU, Min; ZHAO, Wang

    2010-09-01

    to explore the potential role of apolipoprotein A5 (apoA5) on the hypertriglyceridemia (HTG)-lowering effects of statin. twenty-four Sprague-Dawley rats were randomized into 3 groups: (1) control group (n = 8), with no special treatment; (2) HTG group (n = 8), treated with 10% fructose water for 6 weeks; (3) statin group (n = 8), treated with 10% fructose water for 2 weeks and cotreated with atorvastatin 10 mg×kg(-1)×d(-1) for another 4 weeks. Body weight, fasting plasma lipids and the hepatic expressions of apoA5 and peroxisome proliferator activated receptor (PPAR)α were determined. In separate in vitro experiments, we tested the effects of atorvastatin on TG and the expressions of apoA5 and PPARα in HepG2 cells. (1) at 6 weeks, plasma TG was higher in rats in HTG group than in controls, which was significantly reduced in statin group (both P HTG group was significantly lower than in control group and was significantly higher in statin group than in HTG group (both P HTG group was lower than in control group and was higher in statin group than in HTG group (both P < 0.05). (4) Statin significantly upregulated the expressions of apoA5 and PPARα and decreased TG in HepG2 cells. The above effects induced by statin was blocked in the presence of PPARα inhibitor. upregulation of apoA5 expression contributes to TG lowering effect of statin via PPARα signaling pathway.

  3. Bystander effect in human hepatoma HepG2 cells caused by medium transfers at different times after high-LET carbon ion irradiation

    Science.gov (United States)

    Wu, Qingfeng; Li, Qiang; Jin, Xiaodong; Liu, Xinguo; Dai, Zhongying

    2011-01-01

    Although radiation-induced bystander effects have been well documented in a variety of biological systems, whether irradiated cells have the ability to generate bystander signaling persistently is still unclear and the clinical relevance of bystander effects in radiotherapy remains to be elucidated. This study examines tumor cellular bystander response to autologous medium from cell culture irradiated with high-linear energy transfer (LET) heavy ions at a therapeutically relevant dose in terms of clonogenic cell survival. In vitro experiments were performed using human hepatoma HepG2 cell line exposed to 100 keV/μm carbon ions at a dose of 2 Gy. Two different periods (2 and 12 h) after irradiation, irradiated cell conditioned medium (ICCM) and replenished fresh medium were harvested and then transferred to unirradiated bystander cells. Cellular bystander responses were measured with the different medium transfer protocols. Significant higher survival fractions of unirradiated cells receiving the media from the irradiated cultures at the different times post-irradiation than those of the control were observed. Even replenishing fresh medium for unirradiated cells which had been exposed to the ICCM for 12 h could not prevent the bystander cells from the increased survival fraction. These results suggest that the irradiated cells could release unidentified signal factor(s), which induced the increase in survival fraction for the unirradiated bystander cells, into the media sustainedly and the carbon ions triggered a cascade of signaling events in the irradiated cells rather than secreting the soluble signal factor(s) just at a short period after irradiation. Based on the observations in this study, the importance of bystander effect in clinical radiotherapy was discussed and incorporating the bystander effect into the current radiobiological models, which are applicable to heavy ion radiotherapy, is needed urgently.

  4. Bystander effect in human hepatoma HepG2 cells caused by medium transfers at different times after high-LET carbon ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Wu Qingfeng [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Li Qiang, E-mail: liqiang@impcas.ac.c [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000 (China); Jin Xiaodong; Liu Xinguo [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000 (China); Dai Zhongying [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China)

    2011-01-15

    Although radiation-induced bystander effects have been well documented in a variety of biological systems, whether irradiated cells have the ability to generate bystander signaling persistently is still unclear and the clinical relevance of bystander effects in radiotherapy remains to be elucidated. This study examines tumor cellular bystander response to autologous medium from cell culture irradiated with high-linear energy transfer (LET) heavy ions at a therapeutically relevant dose in terms of clonogenic cell survival. In vitro experiments were performed using human hepatoma HepG2 cell line exposed to 100 keV/{mu}m carbon ions at a dose of 2 Gy. Two different periods (2 and 12 h) after irradiation, irradiated cell conditioned medium (ICCM) and replenished fresh medium were harvested and then transferred to unirradiated bystander cells. Cellular bystander responses were measured with the different medium transfer protocols. Significant higher survival fractions of unirradiated cells receiving the media from the irradiated cultures at the different times post-irradiation than those of the control were observed. Even replenishing fresh medium for unirradiated cells which had been exposed to the ICCM for 12 h could not prevent the bystander cells from the increased survival fraction. These results suggest that the irradiated cells could release unidentified signal factor(s), which induced the increase in survival fraction for the unirradiated bystander cells, into the media sustainedly and the carbon ions triggered a cascade of signaling events in the irradiated cells rather than secreting the soluble signal factor(s) just at a short period after irradiation. Based on the observations in this study, the importance of bystander effect in clinical radiotherapy was discussed and incorporating the bystander effect into the current radiobiological models, which are applicable to heavy ion radiotherapy, is needed urgently.

  5. Upregulation of NLRP3 via STAT3-dependent histone acetylation contributes to painful neuropathy induced by bortezomib.

    Science.gov (United States)

    Liu, Cui-Cui; Huang, Zhu-Xi; Li, Xiao; Shen, Kai-Feng; Liu, Meng; Ouyang, Han-Dong; Zhang, Su-Bo; Ruan, Yu-Ting; Zhang, Xiao-Long; Wu, Shao-Ling; Xin, Wen-Jun; Ma, Chao

    2018-01-12

    Painful neuropathy, as a severe side effect of chemotherapeutic bortezomib, is the most common reason for treatment discontinuation. However, the mechanism by which administration of bortezomib leads to painful neuropathy remains unclear. In the present study, we found that application of bortezomib significantly increased the expression of NOD-like receptor family pyrin domain containing 3 (NLRP3) and phosphorylated signal transducer and activator of transcription-3 (STAT3) in dorsal root ganglion (DRG). Intrathecal injection of NLRP3 siRNA significantly prevented the mechanical allodynia induced by bortezomib treatment, and intrathecal injection of recombinant adeno-associated virus vector encoding NLRP3 markedly decreased paw withdrawal threshold of naive rats. Furthermore, the expressions of p-STAT3 were colocalized with NLRP3-positive cells in DRG neurons, and inhibition of STAT3 by intrathecal injection of AAV-Cre-GFP into STAT3 flox/flox mice or inhibitor S3I-201 suppressed the upregulation of NLRP3 and mechanical allodynia induced by bortezomib treatment. Chromatin immunoprecipitation further found that bortezomib increased the recruitment of STAT3, as well as the acetylation of histone H3 and H4, in the NLRP3 promoter region in DRG neurons. Importantly, inhibition of the STAT3 activity by using S3I-201 or DRG local deficiency of STAT3 also significantly prevented the upregulated H3 and H4 acetylation in the NLRP3 promoter region following bortezomib treatment. Altogether, our results suggest that the upregulation of NLRP3 in DRG via STAT3-dependent histone acetylation is critically involved in bortezomib-induced mechanical allodynia. Copyright © 2018. Published by Elsevier Inc.

  6. Involvement of the Up-regulated FoxO1 Expression in Follicular Granulosa Cell Apoptosis Induced by Oxidative Stress*

    Science.gov (United States)

    Shen, Ming; Lin, Fei; Zhang, Jiaqing; Tang, Yiting; Chen, Wei-Kang; Liu, Honglin

    2012-01-01

    Follicular atresia is common in female mammalian ovaries, where most follicles undergo degeneration at any stage of growth and development. Oxidative stress gives rise to triggering granulosa cell apoptosis, which has been suggested as a major cause of follicular atresia. However, the underlying mechanism by which the oxidative stress induces follicular atresia remains unclear. FoxO transcription factors are known as critical mediators in the regulation of oxidative stress and apoptosis. In this study, the involvement of FoxO1 in oxidative stress-induced apoptosis of mouse follicular granulosa cells (MGCs) was investigated in vivo and in vitro. It was observed that increased apoptotic signals correlated with elevated expression of FoxO1 in MGCs when mice were treated with the oxidant. Correspondingly, the expressions of FoxO1 target genes, such as proapoptotic genes and antioxidative genes, were also up-regulated. In primary cultured MGCs, treatment with H2O2 led to FoxO1 nuclear translocation. Further studies with overexpression and knockdown of FoxO1 demonstrated the critical role of FoxO1 in the induction of MGC apoptosis by oxidative stress. Finally, inactivation of FoxO1 by insulin treatment confirmed that FoxO1 induced by oxidative stress played a pivotal role in up-regulating the expression of downstream apoptosis-related genes in MGCs. Our results suggest that up-regulation of FoxO1 by oxidative stress leads to apoptosis of granulosa cells, which eventually results in follicular atresia in mice. PMID:22669940

  7. Hypoxia upregulates Bcl-2 expression and suppresses interferon-gamma induced antiangiogenic activity in human tumor derived endothelial cells.

    LENUS (Irish Health Repository)

    Wang, Jiang Huai

    2012-02-03

    BACKGROUND: Hypoxia in solid tumors potentially stimulates angiogenesis by promoting vascular endothelial growth factor (VEGF) production and upregulating VEGF receptor expression. However, it is unknown whether hypoxia can modulate the effect of anti-angiogenic treatment on tumor-derived endothelium. METHODS: Human tumor-derived endothelial cells (HTDEC) were freshly isolated from surgically removed human colorectal tumors by collagenase\\/DNase digestion and Percol gradient sedimentation. Cell proliferation was assessed by measuring BrdU incorporation, and capillary tube formation was measured using Matrigel. Cell apoptosis was assessed by flow cytometry and ELISA, and Bcl-2 expression was detected by Western blot analysis. RESULTS: Under aerobic culture conditions (5% CO2 plus 21% O2) HTDEC expressed less Bcl-2 and were more susceptible to IFN-gamma-induced apoptosis with significant reductions in both cell proliferation and capillary tube formation, when compared with normal human macrovascular and microvascular EC. Following exposure of HTDEC to hypoxia (5% CO2 plus 2% O2), IFN-gamma-induced cell apoptosis, and antiangiogenic activity (i.e. an inhibition in cell proliferation and capillary tube formation) in HTDEC were markedly attenuated. This finding correlated with hypoxia-induced upregulation of Bcl-2 expression in HTDEC. CONCLUSIONS: These results indicate that hypoxia can protect HTDEC against IFN-gamma-mediated cell death and antiangiogenic activity, and suggest that improvement of tumor oxygenation may potentiate the efficacy of anti-cancer therapies specifically targeting the inhibition of tumor angiogenesis.

  8. Upregulation of glycolysis and oxidative phosphorylation in benzo[α]pyrene and arsenic-induced rat lung epithelial transformed cells.

    Science.gov (United States)

    Chen, Huachen; Lee, Lai-Sheung; Li, Guanwu; Tsao, Sai-Wah; Chiu, Jen-Fu

    2016-06-28

    Arsenic and benzo[α]pyrene (B[a]P) are common contaminants in developing countries. Many studies have investigated the consequences of arsenic and/or B[a]P-induced cellular transformation, including altered metabolism. In the present study, we show that, in addition to elevated glycolysis, B[a]P/arsenic-induced transformation also stimulates oxidative phosphorylation (OXPHOS). Proteomic data and immunoblot studies demonstrated that enzymatic activities, involved in both glycolysis and OXPHOS, are upregulated in the primary transformed rat lung epithelial cell (TLEC) culture, as well as in subcloned TLEC cell lines (TMCs), indicating that OXPHOS was active and still contributed to energy production. LEC expression, of the glycolytic enzyme phosphoglycerate mutase (PGAM) and the TCA cycle enzyme alpha-ketoglutarate dehydrogenase (OGDH), revealed an alternating cyclic pattern of glycolysis and OXPHOS during cell transformation. We also found that the expression levels of hypoxia-inducible factor-1a were consistent with the pattern of glycolysis during the course of transformation. Low doses of an ATP synthase inhibitor depleted endogenous ATP levels to a greater extent in TLECs, compared to parental LECs, indicating greater sensitivity of B[a]P/arsenic-transformed cells to ATP depletion. However, TLEC cells exhibited better survival under hypoxia, possibly due to further induction of anaerobic glycolysis. Collectively, our data indicate that B[a]P/arsenic-transformed cells can maintain energy production through upregulation of both glycolysis and OXPHOS. Selective inhibition of metabolic pathways may serve as a therapeutic option for cancer therapy.

  9. Upregulation of glycolysis and oxidative phosphorylation in benzo[β]pyrene and arsenic-induced rat lung epithelial transformed cells

    Science.gov (United States)

    Li, Guanwu; Tsao, Sai-Wah; Chiu, Jen-Fu

    2016-01-01

    Arsenic and benzo[β]pyrene (B[a]P) are common contaminants in developing countries. Many studies have investigated the consequences of arsenic and/or B[a]P-induced cellular transformation, including altered metabolism. In the present study, we show that, in addition to elevated glycolysis, B[a]P/arsenic-induced transformation also stimulates oxidative phosphorylation (OXPHOS). Proteomic data and immunoblot studies demonstrated that enzymatic activities, involved in both glycolysis and OXPHOS, are upregulated in the primary transformed rat lung epithelial cell (TLEC) culture, as well as in subcloned TLEC cell lines (TMCs), indicating that OXPHOS was active and still contributed to energy production. LEC expression, of the glycolytic enzyme phosphoglycerate mutase (PGAM) and the TCA cycle enzyme alpha-ketoglutarate dehydrogenase (OGDH), revealed an alternating cyclic pattern of glycolysis and OXPHOS during cell transformation. We also found that the expression levels of hypoxia-inducible factor-1β were consistent with the pattern of glycolysis during the course of transformation. Low doses of an ATP synthase inhibitor depleted endogenous ATP levels to a greater extent in TLECs, compared to parental LECs, indicating greater sensitivity of B[a]P/arsenic-transformed cells to ATP depletion. However, TLEC cells exhibited better survival under hypoxia, possibly due to further induction of anaerobic glycolysis. Collectively, our data indicate that B[a]P/arsenic-transformed cells can maintain energy production through upregulation of both glycolysis and OXPHOS. Selective inhibition of metabolic pathways may serve as a therapeutic option for cancer therapy. PMID:27276679

  10. Leptin produced by joint white adipose tissue induces cartilage degradation via upregulation and activation of matrix metalloproteinases.

    Science.gov (United States)

    Hui, Wang; Litherland, Gary J; Elias, Martina S; Kitson, Gareth I; Cawston, Tim E; Rowan, Andrew D; Young, David A

    2012-03-01

    To investigate the effect of leptin on cartilage destruction. Collagen release was assessed in bovine cartilage explant cultures, while collagenolytic and gelatinolytic activities in culture supernatants were determined by bioassay and gelatin zymography. The expression of matrix metalloproteinases (MMP) was analysed by real-time RT-PCR. Signalling pathway activation was studied by immunoblotting. Leptin levels in cultured osteoarthritic joint infrapatellar fat pad or peri-enthesal deposit supernatants were measured by immunoassay. Leptin, either alone or in synergy with IL-1, significantly induced collagen release from bovine cartilage by upregulating collagenolytic and gelatinolytic activity. In chondrocytes, leptin induced MMP1 and MMP13 expression with a concomitant activation of STAT1, STAT3, STAT5, MAPK (JNK, Erk, p38), Akt and NF-κB signalling pathways. Selective inhibitor blockade of PI3K, p38, Erk and Akt pathways significantly reduced MMP1 and MMP13 expression in chondrocytes, and reduced cartilage collagen release induced by leptin or leptin plus IL-1. JNK inhibition had no effect on leptin-induced MMP13 expression or leptin plus IL-1-induced cartilage collagen release. Conditioned media from cultured white adipose tissue (WAT) from osteoarthritis knee joint fat pads contained leptin, induced cartilage collagen release and increased MMP1 and MMP13 expression in chondrocytes; the latter being partly blocked with an anti-leptin antibody. Leptin acts as a pro-inflammatory adipokine with a catabolic role on cartilage metabolism via the upregulation of proteolytic enzymes and acts synergistically with other pro-inflammatory stimuli. This suggests that the infrapatellar fat pad and other WAT in arthritic joints are local producers of leptin, which may contribute to the inflammatory and degenerative processes in cartilage catabolism, providing a mechanistic link between obesity and osteoarthritis.

  11. Metabolomic effects in HepG2 cells exposed to four TiO2 amd two CeO2 naomaterials

    Science.gov (United States)

    Abstract It is difficult to evaluate nanomaterials potential toxicity and to make science-based societal choices. To better assess potential hepatotoxicity issues, human liver HepG2 cells were exposed to four Ti02 and two Ce02 nanomaterials at 30 ug m1-1 for t...

  12. Biochemical effects of six TiO2 and four CeO2 nanomaterials in HepG2 cells

    Science.gov (United States)

    Biochemical effects of six TiO2 and four CeO2 nanomaterials in HepG2 cellsBecause of their growing number of uses, nanoparticles composed of CeO2 (cosmetics, polishing materials and automotive fuel additives) and TiO2 (pigments, sunscreens and photocatalysts) are of particular to...

  13. Inefficient degradation of triglyceride-rich lipoprotein by HepG2 cells is due to a retarded transport to the lysosomal compartment

    NARCIS (Netherlands)

    Lombardi, P.; Mulder, M.; Boom, H. van der; Frants, R.R.; Havekes, L.M.

    1993-01-01

    Binding studies at 37 °C showed that lipoprotein lipase-treated very low density lipoproteins (LPL-VLDL) and very low density lipoproteins (VLDL), once taken up via the low density lipoprotein (LDL) receptor, are poorly degraded by HepG2 cells as compared with LDL. Determination of the initial

  14. Alkaline phosphatase retained in HepG2 hepatocarcinoma cells vs. alkaline phosphatase released to culture medium: difference of aberrant glycosylation.

    Science.gov (United States)

    Nowrouzi, Azin; Yazdanparast, Razieh

    2005-05-06

    Liver tissue is the source of 90% of serum alkaline phosphatase (AP). The serum levels and structures of tumor marker proteins change under many disease conditions as well as cancer. The study was aimed at determining the type of alkaline phosphatase (AP) present in HepG2 hepatocellular carcinoma cell line. Alkaline phosphatase rich extracts of healthy human liver, HepG2 hepatocarcinoma cells, as well as the condition medium of HepG2 cells were prepared by extraction with 40% n-butanol and 30-50% acetone precipitation, and subjected to various chromatographic procedures. Lectin affinity chromatography of the samples with concanavalin A-Sepharose 4B showed considerable differences in the elution patterns. Non-denaturing polyacrylamide gel electrophoresis of the culture medium yielded a relatively slow migrating band of activity that coincided with none of the three bands of activity produced by the normal liver extract, nor with the bands of the cell pellet extract. Inhibition patterns were established by measuring the enzyme activities in the presence of varying concentrations of L-phenylalanine, L-leucine, L-homoarginine, and levamisole. The APs from the cell line were neuraminidase sensitive. According to the results the main AP produced and released to the medium by HepG2 cell line is an aberrantly glycosylated tissue non-specific AP. In addition, the differences between the cell-pellet AP and the culture medium AP seemed to stem from different sugar moieties in their structures.

  15. Metabolomic effects of CeO2, SiO2 and CuO metal oxide nanomaterials on HepG2 cells

    Data.gov (United States)

    U.S. Environmental Protection Agency — The data set is a matrix of cellular biochemical (metabolites) in HepG2 cells treated with various metal oxide nanomaterials composed of CeO2, SiO2 and CuO. This...

  16. Metabolomic effects of CeO2, SiO2 and CuO metal oxide nanomaterials on HepG2 cells

    Science.gov (United States)

    Abstract Background To better assess potential hepatotoxicity of nanomaterials, human liver HepG2 cells were exposed for 3 days to five different CeO2 (either 30 or 100 μg/ml), 3 SiO2 based (30 μg/ml) or 1 CuO (3 μg/ml) nanomaterials with dry primary particle sizes r...

  17. [Over-expression of uracil DNA glycosylase 2 (UNG2) enhances the resistance to oxidative damage in HepG2 cells].

    Science.gov (United States)

    Cao, Liyan; Cheng, Shan; Du, Juan; Guo, Yanhai; Huang, Xiaofeng

    2017-04-01

    Objective To investigate the uracil glycosidic enzyme activity of uracil DNA glycosylase 2 (UNG2) and study the role of UNG2 in the resistance of antioxidant stress of HepG2 cells. Methods The UNG2-expressing vector was built. Western blotting was used to detect the expression of UNG2. Immunofluorescence staining was performed to observe the cellular location of UNG2. Oligonucleotide was used as substrate for the determination of the UNG2 glycosidic enzyme activity. H 2 O 2 toxicity assay was done to study the function of UNG2 in the antioxidant resistance of hepatocellular carcinoma HepG2 cells. Results UNG2 was successfully over-expressed in HEK293FT cells, and UNG2 was found to be mainly located in nucleus. Enzyme activity assay showed that UNG2 had significant oligonucleotide dU glycosidic enzyme activity. H 2 O 2 toxicity assay showed that over-expressed UNG2 could remarkably increase the survival of HepG2 cells after exposed to H 2 O 2 . Conclusion UNG2 possesses specific DNA glycosidic enzyme activity, and it can protect HepG2 cells against oxidative stress damage.

  18. DIFFERENTIAL-EFFECTS OF EICOSAPENTAENOIC ACID ON GLYCEROLIPID AND APOLIPOPROTEIN-B METABOLISM IN PRIMARY HUMAN HEPATOCYTES COMPARED TO HEPG2 CELLS AND PRIMARY RAT HEPATOCYTES

    NARCIS (Netherlands)

    LIN, YG; SMIT, MJ; HAVINGA, R; VERKADE, HJ; VONK, RJ; KUIPERS, F

    1995-01-01

    We compared the effects of eicosapentaenoic acid (EPA) and oleic acid (OA) on glycerolipid and apolipoprotein B (apoB) metabolism in primary human hepatocytes, HepG2 cells and primary rat hepatocytes. Cells were incubated for 1 to 5 h with 0.25 mM bovine serum albumin in the absence (control) or

  19. Apoptotic and Inhibitory Effects on Cell Proliferation of Hepatocellular Carcinoma HepG2 Cells by Methanol Leaf Extract of Costus speciosus

    Directory of Open Access Journals (Sweden)

    Sandhya V. G. Nair

    2014-01-01

    Full Text Available Costus speciosus is a medicinal plant commonly known as wild ginger distributed in South and Southeast Asian countries. Leaves of this plant are used for ayurvedic treatment regimes in malignancies and mental illness. Rhizome extract from the plant is used to treat malignancies, pneumonia, urinary disorders, jaundice, rheumatism, and diabetes. The goal of this study was to investigate the effects of methanol extract of leaves of C. speciosus on the growth of human hepatocellular carcinoma (HepG2 cells and understand possible mechanisms of its action. Viability of HepG2 cells were measured by MTS assay after 24 h and 48 h treatment with extracts of 1, 10, 50, 100, and 200 μg/mL concentrations. Cell cycle analysis and apoptosis were evaluated by flow cytometry and caspase-3 induction. HepG2 cells treated with 100 μg/mL methanol leaf extract for 24 h displayed a significant reduction in cell viability (P≤0.05. The methanol extract perturbed cell cycle progression, modulated cell cycle and regulated, signal molecules were involved in induction of apoptosis in HepG2 cells. Our findings indicate that phytochemicals of leaves of C. speciosus shows potential for natural therapeutic product development for hepatocellular carcinoma. This is the first report to demonstrate in vitro anticancer activity of leaf extract of C. speciosus in relation to liver cancer.

  20. Functional involvement of proteins, interacting with sphingolipids, in sphingolipid transport to the canalicular membrane in the human hepatocytic cell line, HepG2?

    NARCIS (Netherlands)

    Zegers, MMP; Zaal, KJM; Hoekstra, D

    A photoreactive sphingolipid precursor was used to investigate the potential involvement of protein-lipid interactions that may convey specificity to sphingolipid transport in the human hepatoma cell line, HepG2, A I-125-labeled, photoreactive ceramide, I-125-N-3-Cer, was incubated with the cells

  1. Dramatic down-regulation of oxidoreductases in human hepatocellular carcinoma hepG2 cells: proteomics and gene ontology unveiling new frontiers in cancer enzymology

    Directory of Open Access Journals (Sweden)

    Ngoka Lambert CM

    2008-10-01

    Full Text Available Abstract Background Oxidoreductases are enzymes that catalyze many redox reactions in normal and neoplastic cells. Their actions include catalysis of the transformation of free, neutral oxygen gas into oxygen free radicals, superoxide, hydroperoxide, singlet oxygen and hydrogen peroxide. These activated forms of oxygen contribute to oxidative stress that modifies lipids, proteins, DNA and carbohydrates. On the other hand, oxidoreductases constitute one of the most important free radical scavenger systems typified by catalase, superoxide dismutase and glutathione peroxidase. In this work, proteomics, Gene Ontology mapping and Directed Acyclic Graphs (DAG are employed to detect and quantify differential oxidoreductase enzyme expressions between HepG2 cells and normal human liver tissues. Results For the set of bioinformatics calculations whose BLAST searches are performed using the BLAST program BLASTP 2.2.13 [Nov-27-2005], DAG of the Gene Ontology's Molecular Function annotations show that oxidoreductase activity parent node of the liver proteome contains 331 annotated protein sequences, 7 child nodes and an annotation score of 188.9, whereas that of HepG2 cells has 188 annotated protein sequences, 3 child nodes and an annotation score of only 91.9. Overwhelming preponderance of oxidoreductases in the liver is additionally supported by the isomerase DAGs: nearly all the reactions described in the normal liver isomerase DAG are oxidoreductase isomerization reactions, whereas only one of the three child nodes in the HepG2 isomerase DAG is oxidoreductase. Upon normalization of the annotation scores to the parent Molecular Function nodes, oxidoreductases are down-regulated in HepG2 cells by 58%. Similarly, for the set of bioinformatics calculations whose BLAST searches are carried out using BLASTP 2.2.15 [Oct-15-2006], oxidoreductases are down-regulated in HepG2 cells by 56%. Conclusion Proteomics and Gene Ontology reveal, for the first time, differential enzyme activities between HepG2 cells and normal human liver tissues, which may be a promising new prognostic marker of Hepatocellular carcinoma. Two independent sets of bioinformatics calculations that employ two BLAST program versions, and searched different databases, arrived at essentially the same conclusion: oxidoreductases are down-regulated in HepG2 cells by approximately 57%, when compared to normal human liver tissues. Down-regulation of oxidoreductases in hepatoma is additionally supported by Gene Ontology analysis of isomerises.

  2. High-dose acetaminophen inhibits the lethal effect of doxorubicin in HepG2 cells: the role of P-glycoprotein and mitogen-activated protein kinase p44/42 pathway.

    Science.gov (United States)

    Manov, Irena; Bashenko, Yulia; Eliaz-Wolkowicz, Anat; Mizrahi, Meital; Liran, Oded; Iancu, Theodore C

    2007-09-01

    Doxorubicin (DOX) is a widely used chemotherapeutic drug for human hepatocellular carcinoma (HCC). A major limitation to its effectiveness is the development of multidrug resistance of cancer cells. In clinical trials, patients with advanced HCC were treated with high-dose acetaminophen (HAAP) in an effort to improve the antitumor activity of chemotherapeutics. In this study, we investigated the effect of concomitant treatment of DOX and HAAP on hepatoma-derived HepG2 cells. Viability, cell cycle distribution, and ultrastructure were examined. Unexpectedly, HAAP, when added to DOX-exposed cells, increased cell viability, released cell cycle arrest, and decreased apoptosis. To elucidate the mechanisms by which HAAP reduces the DOX lethal effect to HepG2 cells, we investigated the multidrug resistance P-glycoprotein (P-gp) and p44/42-mitogen-activated protein kinase (MAPK) pathways. The P-gp function was enhanced by DOX and HAAP, and it was further stimulated during combined treatment, leading to decreased DOX retention. Verapamil (VRP), when added to DOX + HAAP exposure, increased DOX accumulation and restored DOX-induced toxicity. The increased phospho-p44/42-MAPK level in DOX-exposed cells was inhibited by HAAP. In addition, suppression of p44/42 activation by the p44/42-MAPK inhibitor 2'-amino-3'-methoxyflavone (PD98059) blocked DOX-induced apoptosis. These findings suggest that the antagonistic effect of concomitant DOX + HAAP treatment occurs as a result of interactive stimulation of P-gp, generating decreased intracellular drug concentrations. Furthermore, inhibition of the p44/42-MAPK phosphorylation by HAAP could abolish the DOX-induced cell death pathway. Thus, combined treatment by DOX + HAAP, intended to improve chemotherapeutic efficacy, could have an opposite effect facilitating cancer cell survival.

  3. miR-451 Up-regulation, Induce Erythroid Differentiation of CD133+cells Independent of Cytokine Cocktails

    Directory of Open Access Journals (Sweden)

    Fatemeh Kouhkan

    2013-06-01

    Full Text Available   Objective(s: Erythropoiesis is regulated by some extrinsic and intrinsic factors as microRNAs (miRNAs. miRNAs are endogenously small non-coding regulatory RNAs which play vital roles in the variety of cellular fate, critical processes; growth, apoptosis, metabolism, survival of the cells and specially differentiation. Several miRNAs such as miR-16 and miR-451 have been shown to be correlated with erythroid differentiation. Taking into account the importance of miRNAs in cellular differentiation, the goal of the present study was to examine the role of miRNAs in hematopoietic stem cells (HSC differentiation into the erythroid cells in the absence of growth factors and stimulatory cytokines.   Materials and Methods: CD133+ stem cells were infected with lentiviruses containing miR-451/miR-16 precursor sequence, erythroid differentiation was evaluated using RT-PCR for hemoglobin chains and surface antigens, also by banzidine staining. Results: MiR-451up-regulation, but not miR-16, could induce α, β and γ-globin expression in CD133+ cells and have strong correlation with appearance of CD71 and CD235a markers in these cells. Moreover, miR-451 up-regulation increases the banzidine positive cells to ~ %40. Conclusion: Our results provide strong evidence that miR-451 up-regulation strongly induces erythroid differentiation and maturation of CD133+ stem cells. Hence, this method may provide a useful technique for the production of artificial blood RBC and be used as a new strategy for gene therapy of hemoglobinopathies, such as β-thalassemias and sickle cell anemia.

  4. Saponins, especially platycodin D, from Platycodon grandiflorum modulate hepatic lipogenesis in high-fat diet-fed rats and high glucose-exposed HepG2 cells

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Yong Pil [Department of Toxicology, College of Pharmacy, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Department of Pharmaceutical Engineering, International University of Korea, Jinju (Korea, Republic of); Choi, Jae Ho; Kim, Hyung Gyun; Khanal, Tilak; Song, Gye Young [Department of Toxicology, College of Pharmacy, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Nam, Myoung Soo [College of Agriculture and Life Sciences, Chungnam National University, Daejeon (Korea, Republic of); Lee, Hyun-Sun [Molecular Cancer Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon (Korea, Republic of); Chung, Young Chul; Lee, Young Chun [Division of Food Science, International University of Korea, Jinju (Korea, Republic of); Jeong, Hye Gwang, E-mail: hgjeong@cnu.ac.kr [Department of Toxicology, College of Pharmacy, Chungnam National University, Daejeon 305-764 (Korea, Republic of)

    2013-03-01

    AMP-activated protein kinase (AMPK) plays a central role in controlling hepatic lipid metabolism through modulating the downstream acetyl CoA carboxylase (ACC) and sterol regulatory element-binding protein-1c (SREBP-1c) pathway. Saponins, particularly platycodin D, from the roots of Platycodon grandiflorum (Changkil saponins, CKS) have a variety of pharmacological properties, including antioxidant and hepatoprotective properties. The aim of this study was to investigate the effects of CKS on hepatic lipogenesis and on the expression of genes involved in lipogenesis, and the mechanisms involved. CKS attenuated fat accumulation and the induction of the lipogenic genes encoding SREBP-1c and fatty acid synthase in the livers of HFD-fed rats and in steatotic HepG2 cells. Blood biochemical analyses and histopathological examinations showed that CKS prevented liver injury. CKS and platycodin D each increased the phosphorylation of AMPK and acetyl-CoA carboxylase in HFD-fed rats and HepG2 cells. The use of specific inhibitors showed that platycodin D activated AMPK via SIRT1/CaMKKβ in HepG2 cells. This study demonstrates that CKS or platycodin D alone can regulate hepatic lipogenesis via an AMPK-dependent signalling pathway. - Highlights: ► CKS attenuated fat accumulation in HFD-fed rats and in steatotic HepG2 cells. ► CKS and its major component, platycodin D, inhibited the levels of SREBP-1 and FAS. ► CKS and platycodin D increased the phosphorylation of AMPK and ACC. ► Platycodin D activated AMPK via SIRT1/CaMKKβ in HepG2 cells.

  5. Construction of heterotypic cell sheets by magnetic force-based 3-D coculture of HepG2 and NIH3T3 cells.

    Science.gov (United States)

    Ito, Akira; Jitsunobu, Hideaki; Kawabe, Yoshinori; Kamihira, Masamichi

    2007-11-01

    Heterotypic 3-D coculture is essential to mimic tissues and organs, because cell-cell interaction between various types of cells is believed to be important for the activation of cellular functions. In this study, magnetic force was applied to construct a 3-D coculture system of HepG2 and NIH3T3 cells as a model of hepatocytes and mesenchymal cells. Magnetite cationic liposomes (MCLs) were used to label target cells. NIH3T3 cells labeled with MCLs were seeded onto ultralow-attachment plates, whose surface is composed of a covalently bound hydrogel layer that is hydrophilic and neutrally charged. When a magnet was placed under the plate, cells accumulated on the bottom of the well. After a 24-h incubation period, the cells formed a multilayered cell sheet, which contained the major mesenchymal extracellular matrix (ECM) components (fibronectin and type I collagen), suggesting that the use of stromal NIH3T3 cells gave sufficient strength to cell sheets. Both NIH3T3 and HepG2 cells were labeled with MCLs, and cocultured by two methods: NIH3T3 cell sheets were constructed and HepG2 cells were subsequently seeded onto NIH3T3 cell sheets, and then allowed to form layered cell sheets by applying magnetic force; or NIH3T3 and HepG2 cells were mixed and then allowed to form mixed cell sheets by applying magnetic force. These heterotypic multilayered cell sheets were successfully constructed and an enhanced albumin secretion by HepG2 cells was observed. These results suggest that the new tissue engineering technique using magnetite nanoparticles and magnetic force, to which we refer to as magnetic force-based tissue engineering (Mag-TE), is a promising approach to construct multilayered cell sheets consisting of heterotypic cocultured cells.

  6. Time course of neurotrophic factor upregulation and retinal protection against light-induced damage after optic nerve section.

    Science.gov (United States)

    Valter, Krisztina; Bisti, Silvia; Gargini, Claudia; Di Loreto, Silvia; Maccarone, Rita; Cervetto, Luigi; Stone, Jonathan

    2005-05-01

    To assess neurotrophic factor upregulation in the retina after damage to the optic nerve and relate that regulation to changes in photoreceptor stability and function. Retinas of adult pigmented (Long-Evans) rats were examined at successive times (1-60 days) after unilateral optic nerve section. The distribution and expression of ciliary neurotrophic factor (CNTF) and basic fibroblast growth factor (FGF-2) and their receptor elements FGFR1 and CNTFRalpha were studied with immunohistochemistry and Western blot analysis. FGF-2 and CNTF mRNA levels were also assessed, with semiquantitative reverse transcription-PCR. Levels and localization of the intracellular signaling molecule ERK and its activated, phosphorylated form pERK, were examined by immunohistochemistry. To assess the correlation between neurotrophic factor levels and their protective effect against light damage, albino (Sprague-Dawley) rats were exposed to bright continuous light (1000 lux) for 24 or 48 hours at successive times after nerve section. The TUNEL technique was used to visualize neuronal cell death in the retina. CNTF upregulation was detected 1 week after optic nerve section, peaked at 2 weeks, and fell to control levels at 4 weeks. CNTF appeared first in the inner retina in the ganglion cells, then in the Muller cells in which it became prominent at the outer limiting membrane (OLM) and in the outer segment (OS) region of photoreceptors. FGF-2 upregulation became prominent, particularly in photoreceptors, 21 to 28 days after surgery, continued to 2 months, and slowly declined thereafter. Double labeling with antibodies to ligand and the receptor showed colocalization of CNTF to its receptor at the OS region, whereas FGF-2-to-FGFR1 binding was found in the outer nuclear (ONL) and outer plexiform (OPL) layers. Optic nerve section provided a significant protective effect against light-induced damage in the first 2 weeks. There was no protection when animals were exposed to damaging light 1 month

  7. Comparison of CD63 Upregulation Induced by NSAIDs on Basophils and Monocytes in Patients with NSAID Hypersensitivity

    Directory of Open Access Journals (Sweden)

    N. Abuaf

    2012-01-01

    Full Text Available Background. An in vitro basophil activation test, based on the detection of CD63 upregulation induced by NSAIDs, has been described. Its clinical significance remains controversial. Objectives. In patients with a history of nonallergic NSAID hypersensitivity, stratified according to the severity of the symptoms, to assess with NSAIDs the predictive value of basophil (BAT and monocyte (MAT activation tests. Patients/Methods. Sixty patients who had NSAIDs-induced or exacerbated urticaria/angiooedema and 20 controls was included. After incubation with NSAIDs or acetaminophen, leukocytes were analysed for CD63 upregulation. Results. With aspirin, the sensitivity (37% and specificity (90% of BAT agree with already published results. In contrast, when patients had had cutaneous and visceral reactions, the frequency of positive BAT 14/22 (64%, P<0.001 or MAT 10/22 (46%, P<0.01 were increased. Conclusions. Positive tests were more frequent among patients having a severe hypersensitivity contrasting with the other patients who had results similar to controls.

  8. Mecamylamine attenuates dexamethasone-induced anxiety-like behavior in association with brain derived neurotrophic factor upregulation in rat brains.

    Science.gov (United States)

    Park, Dong Ik; Kim, Hong Gi; Jung, Woo Ram; Shin, Min Kyoo; Kim, Kil Lyong

    2011-01-01

    Mecamylamine (MEC), which was initially developed as a ganglionic blocker for the treatment of hypertension has been investigated as a potent antagonist for most types of nicotinic acetylcholine receptors (nAChRs). Most studies of MEC have focused on its inhibitory effects for nAChRs; however its biological uses have recently been expanded to the treatment of psychological disorders accompanying anxiety-related symptoms. Although MEC shows obvious anxiolytic action, there is no clear evidence on its function. In this study, we investigated whether MEC affects brain derived neurotrophic factor (BDNF) expression in vitro and in vivo. MEC increased BDNF expression in differentiated SH-SY5Y cells and the cerebral cortex region of rat brains. To determine if the anxiolytic effect of MEC is associated with BDNF upregulation, the elevated plus maze (EPM) task was conducted in a dexamethasone (DEX)-induced anxiety model. MEC reduced DEX-induced anxiety-like behavior, and increased BDNF expression in the cerebral cortex of rats. These results suggest that the anxiolytic effect of MEC in EPM might be associated with BDNF upregulation in the cerebral cortex region of rats. The therapeutic efficacy of MEC for anxiety might be partly dependent on BDNF modulation. Copyright © 2011. Published by Elsevier Ltd.

  9. Analysis of Helicobacter pylori cagA promoter elements required for salt-induced upregulation of CagA expression.

    Science.gov (United States)

    Loh, John T; Friedman, David B; Piazuelo, M Blanca; Bravo, Luis E; Wilson, Keith T; Peek, Richard M; Correa, Pelayo; Cover, Timothy L

    2012-09-01

    Helicobacter pylori infection and consumption of a high-salt diet are each associated with an increased risk for the development of gastric cancer. To investigate potential synergism between these factors, we used a global proteomic approach to analyze H. pylori strains cultured in media containing varying salt concentrations. Among the differentially expressed proteins identified, CagA exhibited the greatest increase in expression in response to high salt concentrations. Analysis of 36 H. pylori strains isolated from patients in two regions of Colombia with differing incidences of gastric cancer revealed marked differences among strains in salt-responsive CagA expression. Sequence analysis of the cagA promoter region in these strains revealed a DNA motif (TAATGA) that was present in either one or two copies. Salt-induced upregulation of CagA expression was detected more commonly in strains containing two copies of the TAATGA motif than in strains containing one copy. Mutagenesis experiments confirmed that two copies of the TAATGA motif are required for salt-induced upregulation of CagA expression. In summary, there is considerable heterogeneity among H. pylori strains in salt-regulated CagA expression, and these differences are attributable to variation in a specific DNA motif upstream of the cagA transcriptional start site.

  10. Optimization of Albumin Secretion and Metabolic Activity of Cytochrome P450 1A1 of Human Hepatoblastoma HepG2 Cells in Multicellular Spheroids by Controlling Spheroid Size.

    Science.gov (United States)

    Nishikawa, Tomoko; Tanaka, Yutaro; Nishikawa, Makiya; Ogino, Yuka; Kusamori, Kosuke; Mizuno, Narumi; Mizukami, Yuya; Shimizu, Kazunori; Konishi, Satoshi; Takahashi, Yuki; Takakura, Yoshinobu

    2017-01-01

    Multicellular spheroids are useful as three-dimensional cell culture systems and for cell-based therapies. Their successful application requires an understanding of the consequences of spheroid size for cellular functions. In the present study, we prepared multicellular spheroids of different sizes using the human hepatoblastoma HepG2 cells, as hepatocytes are frequently used for in vitro drug screening and cell-based therapy. Precise polydimethylsiloxane-based microwells with widths of 360, 450, 560, and 770 µm were fabricated using a micromolding technique. Incubation of HepG2 cells in cell culture plates containing the microwells resulted in the formation of HepG2 spheroids with average diameters of 195, 320, 493, and 548 µm. The cell number per spheroid positively correlated with its diameter, and the viability of HepG2 cells was 94% or above for all samples. The smallest HepG2 spheroids showed the highest albumin secretion. On the other hand, the metabolic activity of 7-ethoxyresorufin, a fluorometric substrate for CYP1A1, increased with increasing spheroid size. These results indicate that controlling spheroid size is important when preparing HepG2 spheroids and that the size of HepG2 spheroids greatly influences the cellular function of HepG2 cells in the spheroids.

  11. Myocardial ischemia-reperfusion induces upregulation of contractile endothelin ETB receptor in rat coronary arteries

    DEFF Research Database (Denmark)

    Skovsted, Gry Freja; Sheykhzade, Majid; Trautner, Simon

    2011-01-01

    to the specific ETB receptor agonist Sarafotoxin 6c (S6c) (1 pM to 30 nM) was investigated after cumulative additions in a sensitive wire-myograph. LAD segments, situated in the post-ischemic area displayed significantly augmented ETB receptor mediated vasoconstriction (68±3% of maximal contraction, n = 7......) compared to coronary arteries from the non-ischemic area (23±6 % of maximal contraction, n = 8) and sham operated rats (22±5% of maximal contraction, n = 5). Increased density of ETB receptors localized in the vascular smooth muscle layer was confirmed by immunohistochemistry in LAD segments from the post...... ETB receptor upregulation. Methods and Results Thirteen Sprague-Dawley male rats (body weight 260-410 g) were anaesthetized with Hypnorm-Midazolam and subjected to 15 min occlusion of left anterior descending coronary artery (LAD) followed by 22 h of reperfusion. The contractile response...

  12. Green tea diet decreases PCB 126-induced oxidative stress in mice by upregulating antioxidant enzymes

    Science.gov (United States)

    Newsome, Bradley J; Petriello, Michael C; Han, Sung Gu; Murphy, Margaret O; Eske, Katryn E; Sunkara, Manjula; Morris, Andrew J; Hennig, Bernhard

    2013-01-01

    Superfund chemicals such as polychlorinated biphenyls pose a serious human health risk due to their environmental persistence and link to multiple diseases. Selective bioactive food components such as flavonoids have been shown to ameliorate PCB toxicity, but primarily in an in vitro setting. Here, we show that mice fed a green tea-enriched diet and subsequently exposed to environmentally relevant doses of coplanar PCB exhibit decreased overall oxidative stress primarily due to the upregulation of a battery of antioxidant enzymes. C57BL/6 mice were fed a low fat diet supplemented with green tea extract (GTE) for 12 weeks and exposed to 5 μmol PCB 126/kg mouse weight (1.63 mg/kg-day) on weeks 10, 11 and 12 (total body burden: 4.9 mg/kg). F2-Isoprostane and its metabolites, established markers of in vivo oxidative stress, measured in plasma via HPLC-MS/MS exhibited five-fold decreased levels in mice supplemented with GTE and subsequently exposed to PCB compared to animals on a control diet exposed to PCB. Livers were collected and harvested for both mRNA and protein analyses, and it was determined that many genes transcriptionally controlled by AhR and Nrf2 proteins were upregulated in PCB-exposed mice fed the green tea supplemented diet. An increased induction of genes such as SOD1, GSR, NQO1 and GST, key antioxidant enzymes, in these mice (green tea plus PCB) may explain the observed decrease in overall oxidative stress. A diet supplemented with green tea allows for an efficient antioxidant response in the presence of PCB 126 which supports the emerging paradigm that healthful nutrition may be able to bolster and buffer a physiological system against the toxicities of environmental pollutants. PMID:24378064

  13. Aspalathin Protects the Heart against Hyperglycemia-Induced Oxidative Damage by Up-Regulating Nrf2 Expression

    Directory of Open Access Journals (Sweden)

    Phiwayinkosi V. Dludla

    2017-01-01

    Full Text Available Aspalathin (ASP can protect H9c2 cardiomyocytes against high glucose (HG-induced shifts in myocardial substrate preference, oxidative stress, and apoptosis. The protective mechanism of ASP remains unknown. However, as one of possible, it is well known that phytochemical flavonoids reduce oxidative stress via nuclear factor (erythroid-derived 2-like 2 (Nrf2 activation resulting in up-regulation of antioxidant genes and enzymes. Therefore, we hypothesized that ASP protects the myocardium against HG- and hyperglycemia-induced oxidative damage by up-regulating Nrf2 expression in H9c2 cardiomyocytes and diabetic (db/db mice, respectively. Using an oxidative stress RT2 Profiler PCR array, ASP at a dose of 1 µM was demonstrated to protect H9c2 cardiomyocytes against HG-induced oxidative stress, but silencing of Nrf2 abolished this protective response of ASP and exacerbated cardiomyocyte apoptosis. Db/db mice and their non-diabetic (db/+ littermate controls were subsequently treated daily for six weeks with either a low (13 mg/kg or high (130 mg/kg ASP dose. Compared to nondiabetic mice the db/db mice presented increased cardiac remodeling and enlarged left ventricular wall that occurred concomitant to enhanced oxidative stress. Daily treatment of mice with ASP at a dose of 130 mg/kg for six weeks was more effective at reversing complications than both a low dose ASP or metformin, eliciting enhanced expression of Nrf2 and its downstream antioxidant genes. These results indicate that ASP maintains cellular homeostasis and protects the myocardium against hyperglycemia-induced oxidative stress through activation of Nrf2 and its downstream target genes.

  14. Epigallocatechin-3-gallate alleviates paraquat-induced acute lung injury and inhibits upregulation of toll-like receptors.

    Science.gov (United States)

    Shen, Haitao; Wu, Na; Liu, Zhenning; Zhao, Hongyu; Zhao, Min

    2017-02-01

    To evaluate the detoxifying effect of epigallocatechin-3-gallate (EGCG) on paraquat (PQ)-induced acute lung injury in mice, and to explore the action mechanisms. Following administration of PQ, the mice received a low, a medium or a high dose of EGCG daily for three days. Histopathology of the lungs were examined by H&E staining. The levels of inflammatory cytokines, such as TNF-α, IL-1β and IL-6, in the bronchoalveolar lavage fluid were measured by enzyme-linked immunosorbent assay. Activation of NF-κB was assessed by Western blot and electrophoretic mobility gel shift assay. The expression of toll-like receptor (TLR)-2, 4, 9 and TLR adaptors (MyD88 and TRAF6) was detected by Western blot and immunohistochemical staining. The protective effect of EGCG against PQ toxicity was validated in vitro using A549 lung cancer cell line. Treatment with EGCG dose-dependently attenuated PQ-induced acute lung injury in mice by reducing alveolar edema, hemorrhage, inflammatory cell infiltration and production of inflammatory cytokines. EGCG inhibited the activation of NF-κB and the upregulation of TLR 2, 4 and 9 as well as their adaptors MyD88 and TRAF6 in the lungs following PQ challenge. In addition, EGCG significantly reduced PQ-induced cell death, cytokine production, activation of NF-κB, and upregulation of TLRs and adaptors in A549 cells. Our data suggest that TLR-mediated activation of NF-κB in the non-immune pulmonary cells could be involved in PQ-induced acute lung injury, and it may serve as a target of EGCG against PQ pulmonary toxicity. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Up-regulation of heme oxygenase-1 protects against cold injury-induced brain damage: a laboratory-based study.

    Science.gov (United States)

    Shih, Ruey-Horng; Cheng, Shin-Ei; Tung, Wei-Hsuan; Yang, Chuen-Mao

    2010-08-01

    Heme oxygenase-1 (HO-1), a kind of stress protein, is critical for the protection against ischemic stroke and cerebrovascular endothelium damage. However, the effects of HO-1 on trauma-induced brain injury are still unknown. Hence, we attempted to use a cold injury-induced brain trauma (CIBT) model in mice, which provides for a well-established approach for assessing brain edema and blood-brain barrier breakdown. Additionally, we explored cultured mouse brain endothelial cells (bEnd.3) to investigate the protective effects of HO-1. HO-1 was induced by infection with a recombinant adenovirus carrying the human HO-1 gene or an inducer of HO-1 activity, cobalt protoporphyrin IX (CoPP). The recombinant adenovirus (3.5 x 10(7) PFU/mouse, i.v.) or CoPP (10 mg/kg, i.v.) significantly increased HO-1 protein expression and HO-1 enzyme activity in the cerebral cortex of the mice. We found that overexpression of HO-1 protected against cold injury-induced secondary damage and behavioral impairment. Up-regulation of HO-1 decreased brain edema and neutrophil infiltration induced by cold injury. These HO-1-dependent protecting effects were abrogated by pretreatment with the HO-1 inhibitor, zinc protoporphyrin IX (ZnPP; 3 mg/kg, i.v.). HO-1 expression in the cerebral endothelium was observed by immunofluorescent staining. CoPP-induced (1 muM, 24 h) HO-1 protein expression was determined by western blotting in bEnd.3 cells. Enhanced HO-1 also protected against cold injury-induced cell loss and damage, which were respectively determined by GAPDH leakage into the cell medium and XTT assay in bEnd.3 cells. In summary, HO-1 overexpression appears to offer an effective neuroprotection against cold-induced secondary brain injury.

  16. Distribution of mitochondrial nucleoids upon mitochondrial network fragmentation and network reintegration in HEPG2 cells.

    Science.gov (United States)

    Tauber, Jan; Dlasková, Andrea; Šantorová, Jitka; Smolková, Katarína; Alán, Lukáš; Špaček, Tomáš; Plecitá-Hlavatá, Lydie; Jabůrek, Martin; Ježek, Petr

    2013-03-01

    Mitochondrial DNA (mtDNA) is organized in nucleoids in complex with accessory proteins, proteins of mtDNA replication and gene expression machinery. A robust mtDNA genome is represented by hundreds to thousands of nucleoids in cell mitochondrion. Detailed information is lacking about the dynamics of nucleoid distribution within the mitochondrial network upon physiological and pathological events. Therefore, we used confocal microscopy to study mitochondrial nucleoid redistribution upon mitochondrial fission and following reintegration of the mitochondrial network. Fission was induced by oxidative stress at respiration inhibition by rotenone or upon elimination of the protonmotive force by uncoupling or upon canceling its electrical component, ΔΨ(m), by valinomycin; and by silencing of mitofusin MFN2. Agent withdrawal resulted in concomitant mitochondrial network reintegration. We found two major principal morphological states: (i) a tubular state of the mitochondrial network with equidistant nucleoid spacing, 1.10±0.2 nucleoids per μm, and (ii) a fragmented state of solitary spheroid objects in which several nucleoids were clustered. We rarely observed singular mitochondrial fragments with a single nucleoid inside and very seldom we observed empty fragments. Reintegration of fragments into the mitochondrial network re-established the tubular state with equidistant nucleoid spacing. The two major morphological states coexisted at intermediate stages. These observations suggest that both mitochondrial network fission and reconnection of the disintegrated network are nucleoid-centric, i.e., fission and new mitochondrial tubule formation are initiated around nucleoids. Analyses of combinations of these morphological icons thus provide a basis for a future mitochondrial morphology diagnostics. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Cytotoxicity of Triterpenes from Green Walnut Husks of Juglans mandshurica Maxim in HepG-2 Cancer Cells.

    Science.gov (United States)

    Zhou, Yuanyuan; Yang, Bingyou; Liu, Zhaoxi; Jiang, Yanqiu; Liu, Yuxin; Fu, Lei; Wang, Xiaoli; Kuang, Haixue

    2015-10-22

    Among the classes of identified natural products, triterpenoids, one of the largest families, have been studied extensively for their diverse structures and variety of biological activities, including antitumor effects. In the present study, a phytochemical study of the green walnut husks of Juglans mandshurica Maxim led to the isolation of a new dammarane triterpene, 12β, 20(R), 24(R)-trihydroxydammar-25-en-3-one (6), together with sixteen known compounds, chiefly from chloroform and ethyl acetate extracts. According to their structural characteristics, these compounds were divided into dammarane-type, oleanane- and ursane-type. Dammarane-type triterpenoids were isolated for the first time from the Juglans genus. As part of our continuing search for biologically active compounds from this plant, all of these compounds were also evaluated for their cytotoxic activities against the growth of human cancer cells lines HepG-2 by the MTT assay. The results were shown that 20(S)-protopanaxadiol, 2α,3β,23-trihydroxyolean-12-en-28-oic acid and 2α,3β,23-trihydroxyurs-12-en-28-oic acid exhibited better cytotoxicity in vitro with IC50 values of 10.32±1.13, 16.13±3.83, 15.97±2.47 μM, respectively. Preliminary structure-activity relationships for these compounds were discussed.

  18. Inhibitory effects of Citrus flavonoids on starch digestion and antihyperglycemic effects in HepG2 cells.

    Science.gov (United States)

    Shen, Wei; Xu, Ying; Lu, Yan-Hua

    2012-09-26

    Flavonoids are a class of important bioactive natural products and are being extensively used in functional foods. In the present study, the effects of four Citrus flavonoids (i.e., hesperidin, naringin, neohesperidin, and nobiletin) on amylase-catalyzed starch digestion, major digestive enzyme activities (e.g., pancreatic α-amylase and α-glucosidase), and glucose use in HepG2 cells were investigated. The results showed that all of the tested Citrus flavonoids significantly inhibited amylase-catalyzed starch digestion. Moreover, naringin and neohesperidin mainly inhibited amylose digestion, whereas hesperidin and nobiletin inhibited both amylose and amylopectin digestion. However, these flavonoids showed weak inhibitory activities against digestive enzymes. Furthermore, glucose consumption, glycogen concentration, and glucokinase activity were significantly elevated, and glucose-6-phosphatase activity was markedly decreased by Citrus flavonoids. These results demonstrate that Citrus flavonoids play important roles in preventing the progression of hyperglycemia, partly by binding to starch, increasing hepatic glycolysis and the glycogen concentration, and lowering hepatic gluconeogenesis. This work suggests that Citrus flavonoids might be potentially used for the prevention of postprandial hyperglycemia.

  19. Antagonism of Secreted PCSK9 Increases Low Density Lipoprotein Receptor Expression in HepG2 Cells

    Energy Technology Data Exchange (ETDEWEB)

    McNutt, Markey C.; Kwon, Hyock Joo; Chen, Chiyuan; Chen, Justin R.; Horton, Jay D.; Lagace, Thomas A.; (USMC); (UTSMC)

    2009-07-10

    PCSK9 is a secreted protein that degrades low density lipoprotein receptors (LDLRs) in liver by binding to the epidermal growth factor-like repeat A (EGF-A) domain of the LDLR. It is not known whether PCSK9 causes degradation of LDLRs within the secretory pathway or following secretion and reuptake via endocytosis. Here we show that a mutation in the LDLR EGF-A domain associated with familial hypercholesterolemia, H306Y, results in increased sensitivity to exogenous PCSK9-mediated cellular degradation because of enhanced PCSK9 binding affinity. The crystal structure of the PCSK9-EGF-A(H306Y) complex shows that Tyr-306 forms a hydrogen bond with Asp-374 in PCSK9 at neutral pH, which strengthens the interaction with PCSK9. To block secreted PCSK9 activity, LDLR (H306Y) subfragments were added to the medium of HepG2 cells stably overexpressing wild-type PCSK9 or gain-of-function PCSK9 mutants associated with hypercholesterolemia (D374Y or S127R). These subfragments blocked secreted PCSK9 binding to cell surface LDLRs and resulted in the recovery of LDLR levels to those of control cells. We conclude that PCSK9 acts primarily as a secreted factor to cause LDLR degradation. These studies support the concept that pharmacological inhibition of the PCSK9-LDLR interaction extracellularly will increase hepatic LDLR expression and lower plasma low density lipoprotein levels.

  20. Generation of Multilayered 3D Structures of HepG2 Cells Using a Bio-printing Technique.

    Science.gov (United States)

    Jeon, Hyeryeon; Kang, Kyojin; Park, Su A; Kim, Wan Doo; Paik, Seung Sam; Lee, Sang-Hun; Jeong, Jaemin; Choi, Dongho

    2017-01-15

    Chronic liver disease is a major widespread cause of death, and whole liver transplantation is the only definitive treatment for patients with end-stage liver diseases. However, many problems, including donor shortage, surgical complications and cost, hinder their usage. Recently, tissue-engineering technology provided a potential breakthrough for solving these problems. Three-dimensional (3D) printing technology has been used to mimic tissues and organs suitable for transplantation, but applications for the liver have been rare. A 3D bioprinting system was used to construct 3D printed hepatic structures using alginate. HepG2 cells were cultured on these 3D structures for 3 weeks and examined by fluorescence microscopy, histology and immunohistochemistry. The expression of liverspecific markers was quantified on days 1, 7, 14, and 21. The cells grew well on the alginate scaffold, and liver-specific gene expression increased. The cells grew more extensively in 3D culture than two-dimensional culture and exhibited better structural aspects of the liver, indicating that the 3D bioprinting method recapitulates the liver architecture. The 3D bioprinting of hepatic structures appears feasible. This technology may become a major tool and provide a bridge between basic science and the clinical challenges for regenerative medicine of the liver.

  1. Prediction of liver toxicity and mode of action using metabolomics in vitro in HepG2 cells.

    Science.gov (United States)

    Ramirez, Tzutzuy; Strigun, Alexander; Verlohner, Andreas; Huener, Hans-Albrecht; Peter, Erik; Herold, Michael; Bordag, Natalie; Mellert, Werner; Walk, Tilmann; Spitzer, Michael; Jiang, Xiaoqi; Sperber, Saskia; Hofmann, Thomas; Hartung, Thomas; Kamp, Hennicke; van Ravenzwaay, Ben

    2017-09-30

    Liver toxicity is a leading systemic toxicity of drugs and chemicals demanding more human-relevant, high throughput, cost effective in vitro solutions. In addition to contributing to animal welfare, in vitro techniques facilitate exploring and understanding the molecular mechanisms underlying toxicity. New 'omics technologies can provide comprehensive information on the toxicological mode of action of compounds, as well as quantitative information about the multi-parametric metabolic response of cellular systems in normal and patho-physiological conditions. Here, we combined mass-spectroscopy metabolomics with an in vitro liver toxicity model. Metabolite profiles of HepG2 cells treated with 35 test substances resulted in 1114 cell supernatants and 3556 intracellular samples analyzed by metabolomics. Control samples showed relative standard deviations of about 10-15%, while the technical replicates were at 5-10%. Importantly, this procedure revealed concentration-response effects and patterns of metabolome changes that are consistent for different liver toxicity mechanisms (liver enzyme induction/inhibition, liver toxicity and peroxisome proliferation). Our findings provide evidence that identifying organ toxicity can be achieved in a robust, reliable, human-relevant system, representing a non-animal alternative for systemic toxicology.

  2. Caffeine inhibits paclitaxel‑induced apoptosis in colorectal cancer cells through the upregulation of Mcl‑1 levels.

    Science.gov (United States)

    Mhaidat, Nizar M; Alzoubi, Karem H; Al-Azzam, Sayer I; Alsaad, Alhareth A

    2014-01-01

    Colorectal cancer (CRC) cells have been previously observed to be resistant to paclitaxel‑induced apoptosis by activation of the mitogen‑activated protein/extracellular signal‑regulated kinase (MEK)/ERK signaling pathway and increased expression of glucose‑regulated protein 78 (GRP78). Caffeine, the most widely used neuroactive compound, has antiproliferative activity and the ability to induce cell cycle arrest and apoptosis. In the current study, the effect of concomitant use of caffeine on paclitaxel‑induced apoptosis in CRC cells was investigated. The results revealed that treatment of Colo205 cells with varying caffeine concentrations did not induce apoptosis. Pretreatment of CRC cells with caffeine significantly inhibited paclitaxel‑induced cytotoxicity by increasing the levels of the antiapoptotic Bcl‑2 family member, Mcl‑1. This effect was inhibited by pretreatment of Colo205 cells with the MEK‑ERK chemical inhibitor, U0126. In addition to GRP78, these results indicated that Mcl‑1 may be a downstream target of the MEK‑ERK signaling pathway. Moreover, administration of caffeine may decrease chemotherapeutic responses to paclitaxel by the MEK‑ERK mediated upregulation of Mcl‑1. In conclusion, coadministration of cell cycle‑modifying agents, including caffeine should be avoided in CRC patients treated with paclitaxel.

  3. Caveolin-1 mediates tissue plasminogen activator-induced MMP-9 up-regulation in cultured brain microvascular endothelial cells.

    Science.gov (United States)

    Jin, Xinchun; Sun, Yanyun; Xu, Ji; Liu, Wenlan

    2015-03-01

    Thrombolysis with tissue plasminogen activator (tPA) increases matrix metalloproteinase-9 (MMP-9) activity in the ischemic brain, which exacerbates blood-brain barrier injury and increases the risk of symptomatic cerebral hemorrhage. The mechanism through which tPA enhances MMP-9 activity is not well understood. Here we report an important role of caveolin-1 in mediating tPA-induced MMP-9 synthesis. Brain microvascular endothelial cell line bEnd3 cells were incubated with 5 or 20 μg/ml tPA for 24 hrs before analyzing MMP-9 levels in the conditioned media and cellular extracts by gelatin zymography. tPA at a dose of 20 μg/mL tPA, but not 5 μg/mL, significantly increased MMP-9 level in cultured media while decreasing it in cellular extracts. Concurrently, tPA treatment induced a 2.3-fold increase of caveolin-1 protein levels in endothelial cells. Interestingly, knockdown of Cav-1 with siRNA inhibited tPA-induced MMP-9 mRNA up-regulation and MMP-9 increase in the conditioned media, but did not affect MMP-9 decrease in cellular extracts. These results suggest that caveolin-1 critically contributes to tPA-mediated MMP-9 up-regulation, but may not facilitate MMP-9 secretion in endothelial cells. Thrombolysis with tissue plasminogen activator (tPA) increases matrix metalloproteinase-9 (MMP-9) activity in the ischemic brain, which exacerbates ischemic blood brain barrier (BBB) injury and increases the risk of symptomatic cerebral hemorrhage. Our results suggest a novel mechanism underlying this tPA-MMP 9 axis. In response to tPA treatment, caveolin-1 protein levels increased in endothelial cells, which mediate MMP-9 mRNA up-regulation and its secretion into extracellular space. Caveolin-1 may, however, not facilitate MMP-9 secretion in endothelial cells. Our data suggest caveolin-1 as a novel therapeutic target for protecting the BBB against ischemic damage. The schematic outlines tPA-induced MMP-9 upreguation. © 2015 International Society for Neurochemistry.

  4. Zoledronate upregulates MMP-9 and -13 in rat vascular smooth muscle cells by inducing oxidative stress

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    Arun MZ

    2016-04-01

    Full Text Available Mehmet Zuhuri Arun,1 Buket Reel,1 Graciela B Sala-Newby,2 Mark Bond,2 Aikaterini Tsaousi,2 Perry Maskell,2 Andrew C Newby21Department of Pharmacology, Faculty of Pharmacy, Ege University, Izmir, Turkey; 2Bristol Heart Institute, University of Bristol, Bristol Royal Infirmary, Bristol, UK Background: Bisphosphonates, including zoledronate, target osteoclasts and are widely used in the treatment of osteoporosis and other bone resorption diseases, despite side effects that include damaging the stomach epithelium. Beneficial and adverse effects on other organ systems, including the cardiovascular system, have also been described and could impact on the use of bisphosphonates as therapeutic agents. Vascular smooth muscle cells (VSMCs are major constituents of the normal vascular wall and have a key role in intimal thickening and atherosclerosis, in part by secreting MMPs that remodel the extracellular matrix and cleave cell surface proteins or secreted mediators. In this study, we investigated the effects of zoledronate on MMP expression.Methods: Rat VSMCs were stimulated by PDGF (50 ng/mL plus TNF-α (10 ng/mL or left unstimulated for a further 24 hours in serum-free medium. In other series of experiments, cells were pre-treated either with SC-514 (50 µM or with apocynin (20 nM for 2 hours, then zoledronate (100 µM was added into 2% fetal calf serum containing medium for 24 hours.Results and discussion: Using isolated rat VSMCs in culture, zoledronate (100 µM increased MMP-9 and -13 mRNA expressions but inhibited MMP-2 expression. MMP-9 and MMP-13 up-regulation was shown to depend on the NF-κB pathway; and this was activated by zoledronate. Furthermore, zoledronate elevated the levels of reactive oxygen species detected by either dichlorofluorescein in isolated VSMCs or lucigenin enhanced chemiluminescence in rat aortic rings in vitro. Apocynin, an inhibitor of NADPH oxidase, reversed NF-κB activation and MMP-9 and MMP-13 up-regulation by

  5. Colonic PDGFRα Overexpression Accompanied Forkhead Transcription Factor FOXO3 Up-Regulation in STZ-Induced Diabetic Mice

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    Hongli Lu

    2017-08-01

    short hairpin RNA (shRNA in NIH cells. The expression of phosphorylated Akt was significantly down-regulated in diabetic colonic muscle tissue. Conclusions: These results suggest that diabetes-induced colonic PDGFRα+ cell proliferation is mediated by FOXO3 up-regulation. FOXO3 up-regulation may be induced by inhibiting the PI3K/Akt signaling pathway in STZ-induced diabetic mice. PDGFRα+ cell proliferation could be a new target for clinical therapy of diabetes-induced colonic transit disorder.

  6. Simvastatin induces a central hypotensive effect via Ras-mediated signalling to cause eNOS up-regulation

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    Cheng, Wen-Han; Ho, Wen-Yu; Chang, Chien-Feng; Lu, Pei-Jung; Cheng, Pei-Wen; Yeh, Tung-Chen; Hong, Ling-Zong; Sun, Gwo-Ching; Hsiao, Michael; Tseng, Ching-Jiunn

    2013-01-01

    BACKGROUND AND PURPOSE Clinical studies indicate that statins have a BP-lowering effect in hypercholesterolemic individuals with hypertension. Specifically, statins modulate BP through the up-regulation of endothelial NOS (eNOS) activation in the brain. However, the signalling mechanisms through which statins enhance eNOS activation remain unclear. Therefore, we examined the possible signalling pathways involved in statin-mediated BP regulation in the nucleus tractus solitarii (NTS). EXPERIMENTAL APPROACH To investigate the involvement of Ras and other signalling pathways in simvastatin-induced effects on BP, BP and renal sympathetic nerve activity (RSNA) were determined in spontaneously hypertensive rats (SHRs) before and after i.c.v. administration of simvastatin in the absence and presence of a Ras-specific inhibitor (farnesyl thiosalicylic acid, FTS), a geranylgeranyltransferase inhibitor (GGTI-2133), a PI3K inhibitor (LY294002) or a MAPK-ERK kinase (MEK) inhibitor (PD98059). KEY RESULTS FTS significantly attenuated the decrease in BP and increased NO evoked by simvastatin and reversed the decrease in basal RSNA induced by simvastatin. Immunoblotting and pharmacological studies showed that inhibition of Ras activity by FTS significantly abolished simvastatin-induced phosphorylation of ERK1/2, ribosomal protein S6 kinase (RSK), Akt and decreased eNOS phosphorylation. Likewise, administration of Akt and ERK1/2 signalling inhibitors, LY294002 and PD98059, attenuated the reduction in BP evoked by simvastatin. Furthermore, i.c.v. simvastatin decreased Rac1 activation and the number of ROS-positive cells in the NTS. CONCLUSIONS AND IMPLICATIONS Simvastatin modulates central BP control in the NTS of SHRs by increasing Ras-mediated activation of the PI3K-Akt and ERK1/2-RSK signalling pathways, which then up-regulates eNOS activation. PMID:23889671

  7. Heteroconium chaetospira induces resistance to clubroot via upregulation of host genes involved in jasmonic acid, ethylene, and auxin biosynthesis.

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    Rachid Lahlali

    Full Text Available An endophytic fungus, Heteroconium chaetospira isolate BC2HB1 (Hc, suppressed clubroot (Plasmodiophora brassicae -Pb on canola in growth-cabinet trials. Confocal microscopy demonstrated that Hc penetrated canola roots and colonized cortical tissues. Based on qPCR analysis, the amount of Hc DNA found in canola roots at 14 days after treatment was negatively correlated (r = 0.92, P<0.001 with the severity of clubroot at 5 weeks after treatment at a low (2×10(5 spores pot(-1 but not high (2×10(5 spores pot(-1 dose of pathogen inoculum. Transcript levels of nine B. napus (Bn genes in roots treated with Hc plus Pb, Pb alone and a nontreated control were analyzed using qPCR supplemented with biochemical analysis for the activity of phenylalanine ammonia lyases (PAL. These genes encode enzymes involved in several biosynthetic pathways related potentially to plant defence. Hc plus Pb increased the activity of PAL but not that of the other two genes (BnCCR and BnOPCL involved also in phenylpropanoid biosynthesis, relative to Pb inoculation alone. In contrast, expression of several genes involved in the jasmonic acid (BnOPR2, ethylene (BnACO, auxin (BnAAO1, and PR-2 protein (BnPR-2 biosynthesis were upregulated by 63, 48, 3, and 3 fold, respectively, by Hc plus Pb over Pb alone. This indicates that these genes may be involved in inducing resistance in canola by Hc against clubroot. The upregulation of BnAAO1 appears to be related to both pathogenesis of clubroot and induced defence mechanisms in canola roots. This is the first report on regulation of specific host genes involved in induced plant resistance by a non-mycorrhizal endophyte.

  8. Proteomic analysis of upregulated proteins in Helicobacter pylori under oxidative stress induced by hydrogen peroxide

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    Chun-Hao Huang

    2011-12-01

    Full Text Available The development of gastric cancer was suggested to be associated with chronic inflammation as a consequence of Helicobacter pylori infection. Such inflammation-related oxidative stress induced by reactive oxygen species (ROS in vivo may exert bidirectional effects on both hosts and H pylori. In this study, ROS-induced oxidative stress was mimicked by coculture of gastric epithelial cells with H pylori treated with hydrogen peroxide (H2O2. To investigate the effect of H2O2 on the proteome of H pylori, we performed two-dimensional polyacrylamide gel electrophoresis followed by liquid chromatography coupled with nano-electrospray ionization-tandem mass spectrometry (liquid chromatography mass spectrometry and bioinformatics database analysis. The nine most overexpressed proteins consisted of three virulence factors, including cytotoxin-associated protein A (CagA, vacuolating cytotoxin (VacA, adherence-associated protein (AlpA, and two antioxidant enzymes alkylhydroperoxide reductase (AhpC and catalase (KatA, plus one serine protease (HtrA, aconitate hydratase, and fumarate reductase. We have also confirmed the upregulation of virulence factors and antioxidant proteins in several H pylori strains isolated from patients of different clinical outcomes. Furthermore, it is noted that H pylori was found to decrease in infection rate and increase in proliferation after being exposed to H2O2. We also found that gastric epithelial cells can be protected from oxidative damage by H2O2 in the presence of H pylori. In conclusion, this study lends support to the supposition that ROS containing H2O2 as one of the major oxidative species can induce upregulation of virulence factors and antioxidant enzymes in H pylori, which may aid in the elucidation of inflammation leading to the development of gastric cancer from H pylori infection.

  9. Apocynin protects against ethanol-induced gastric ulcer in rats by attenuating the upregulation of NADPH oxidases 1 and 4.

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    El-Naga, Reem N

    2015-12-05

    Gastric ulcer is a common gastrointestinal disorder affecting many people all over the world. Absolute ethanol (5 ml/kg) was used to induce gastric ulceration in rats. Apocynin (50 mg/kg) was given orally one hour before the administration of absolute ethanol. Omeprazole (20 mg/kg) was used as a standard. Interestingly, apocynin pre-treatment provided 93.5% gastroprotection against ethanol-induced ulceration. Biochemically, gastric mucin content was significantly increased with apocynin pre-treatment. This finding was further supported by alcian blue staining of stomach sections obtained from the different treated groups. Also, gastric juice volume and acidity were significantly reduced. Apocynin significantly ameliorated ethanol-induced oxidative stress by replenishing reduced glutathione and superoxide dismutase levels as well as reducing elevated malondialdehyde levels in gastric tissues. Besides, ethanol-induced pro-inflammatory response was significantly decreased by apocynin pre-treatment via reducing elevated levels of pro-inflammatory markers; interleukin-1β, tumor necrosis factor-α, cyclooxygenase-2 and inducible nitric oxide synthase. Additionally, caspase-3 tissue level was significantly reduced in apocynin pre-treated group. Interestingly, NADPH oxidase-1 (NOX-1) and NOX-4 up-regulation was shown to be partially involved in the pathogenesis of ethanol-induced gastric ulceration and was significantly reversed by apocynin pre-treatment. Gastroprotective properties of apocynin were confirmed by histopathological examination. It is worth mentioning that apocynin was superior in all aspects except gastric mucin content parameter where it was significantly increased by 13.5 folds in the omeprazole pre-treated group. This study was the first to show that apocynin is a promising gastroprotective agent against ethanol-induced gastric ulceration, partially via its anti-oxidant, anti-inflammatory, anti-apoptotic effects as well as down-regulating NOX-1 and NOX-4

  10. MicroRNAs Up-Regulated by CagA of Helicobacter pylori Induce Intestinal Metaplasia of Gastric Epithelial Cells

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    Zhu, Yongliang; Jiang, Qiaoli; Lou, Xiaojun; Ji, Xiaowei; Wen, Zhenzhen; Wu, Jia; Tao, Haiying; Jiang, Tingting; He, Wei; Wang, Caihua; Du, Qin; Zheng, Shu; Mao, Jianshan; Huang, Jian

    2012-01-01

    CagA of Helicobacter pylori is a bacterium-derived oncogenic protein closely associated with the development of gastric cancers. MicroRNAs (miRNAs) are a class of widespread non-coding RNAs, many of which are involved in cell growth, cell differentiation and tumorigenesis. The relationship between CagA protein and miRNAs is unclear. Using mammalian miRNA profile microarrays, we found that miRNA-584 and miRNA-1290 expression was up-regulated in CagA-transformed cells, miRNA-1290 was up-regulated in an Erk1/2-dependent manner, and miRNA-584 w