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Sample records for c-met inhibits hepatocyte

  1. Hepatocyte growth factor/cMET pathway activation enhances cancer hallmarks in adrenocortical carcinoma

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    Phan, Liem M.; Fuentes-Mattei, Enrique; Wu, Weixin; Velazquez-Torres, Guermarie; Sircar, Kanishka; Wood, Christopher G.; Hai, Tao; Jimenez, Camilo; Cote, Gilbert J.; Ozsari, Levent; Hofmann, Marie-Claude; Zheng, Siyuan; Verhaak, Roeland; Pagliaro, Lance; Cortez, Maria Angelica; Lee, Mong-Hong; Yeung, Sai-Ching J.; Habra, Mouhammed Amir

    2015-01-01

    Adrenocortical carcinoma (ACC) is a rare malignancy with poor prognosis and limited response to chemotherapy. Hepatocyte growth factor (HGF) and its receptor cMET augment cancer growth and resistance to chemotherapy, but their role in ACC has not been examined. In this study, we investigated the association between HGF/cMET expression and cancer hallmarks of ACC. Transcriptomic and immunohistochemical analyses indicated that increased HGF/cMET expression in human ACC samples was positively associated with cancer-related biological processes including proliferation and angiogenesis, and negatively correlated with apoptosis. Accordingly, treatment of ACC cells with exogenous HCG resulted in increased cell proliferation in vitro and in vivo while short hairpin RNA-mediated knockdown or pharmacological inhibition of cMET suppressed cell proliferation and tumor growth. Moreover, exposure of cells to mitotane, cisplatin, or radiation rapidly induced pro-cMET expression and was associated with an enrichment of genes (e.g., CYP450 family) related to therapy resistance further implicating cMET in the anticancer drug response. Together, these data suggest an important role for HGF/cMET signaling in ACC growth and resistance to commonly used treatments. Targeting cMET, alone or in combination with other drugs, could provide a breakthrough in the management of this aggressive cancer. PMID:26282167

  2. The EGFR/ErbB3 Pathway Acts as a Compensatory Survival Mechanism upon c-Met Inhibition in Human c-Met+ Hepatocellular Carcinoma.

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    Steven N Steinway

    Full Text Available c-Met, a high-affinity receptor for Hepatocyte Growth Factor (HGF, plays a critical role in tumor growth, invasion, and metastasis. Hepatocellular carcinoma (HCC patients with activated HGF/c-Met signaling have a significantly worse prognosis. Targeted therapies using c-Met tyrosine kinase inhibitors are currently in clinical trials for HCC, although receptor tyrosine kinase inhibition in other cancers has demonstrated early success. Unfortunately, therapeutic effect is frequently not durable due to acquired resistance.We utilized the human MHCC97-H c-Met positive (c-Met+ HCC cell line to explore the compensatory survival mechanisms that are acquired after c-Met inhibition. MHCC97-H cells with stable c-Met knockdown (MHCC97-H c-Met KD cells were generated using a c-Met shRNA vector with puromycin selection and stably transfected scrambled shRNA as a control. Gene expression profiling was conducted, and protein expression was analyzed to characterize MHCC97-H cells after blockade of the c-Met oncogene. A high-throughput siRNA screen was performed to find putative compensatory survival proteins, which could drive HCC growth in the absence of c-Met. Findings from this screen were validated through subsequent analyses.We have previously demonstrated that treatment of MHCC97-H cells with a c-Met inhibitor, PHA665752, results in stasis of tumor growth in vivo. MHCC97-H c-Met KD cells demonstrate slower growth kinetics, similar to c-Met inhibitor treated tumors. Using gene expression profiling and siRNA screening against 873 kinases and phosphatases, we identified ErbB3 and TGF-α as compensatory survival factors that are upregulated after c-Met inhibition. Suppressing these factors in c-Met KD MHCC97-H cells suppresses tumor growth in vitro. In addition, we found that the PI3K/Akt signaling pathway serves as a negative feedback signal responsible for the ErbB3 upregulation after c-Met inhibition. Furthermore, in vitro studies demonstrate that

  3. Inhibition of c-Met as a Therapeutic Strategy for Esophageal Adenocarcinoma

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    Gregory A. Watson

    2006-11-01

    Full Text Available The hepatocyte growth factor (HGF receptor c-Met is a tyrosine kinase receptor with established oncogenic properties. We have previously shown that c-Met is usually overexpressed in esophageal adenocarcinoma (EA, yet the implications of c-Met inhibition in EA remain unknown. Three c-Met-overexpressiog EA cell lines (Seg-1, Bic-1, Flo-1 were used to examine the effects of a c-Met-specific small molecule inhibitor (PHA665752 on cell viability, apoptosis, motility, invasion, downstream signaling pathways. PHA665752 demonstrated dose-dependent inhibition of constitutive and/or HGF-induced phosphorylation of c-Met, which correlated with reduced cell viability and inhibition of extracellular regulated kinase 1/2 phosphorylation in all three EA cell lines. In contrast, PHA665752 induced apoptosis and reduced motility and invasion in only one EA cell line, Flo-1. Interestingly, Flo-1 was the only cell line in which phosphatidylinositol 3-kinase (PI3K/Akt was induced following HGF stimulation. The PI3K inhibitor LY294002 produced effects equivalent to those of PHA665752 in these cells. We conclude that inhibition of c-Met may be a useful therapeutic strategy for EA. Factors other than receptor overexpression, such as c-Met-dependent PI3K/Akt signaling, may be predictive of an individual tumor's response to c-Met inhibition.

  4. The c-Met Inhibitor MSC2156119J Effectively Inhibits Tumor Growth in Liver Cancer Models

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    Bladt, Friedhelm, E-mail: Friedhelm.Bladt@merckgroup.com; Friese-Hamim, Manja; Ihling, Christian; Wilm, Claudia; Blaukat, Andree [EMD Serono, and Merck Serono Research and Development, Merck KGaA, Darmstadt 64293 (Germany)

    2014-08-19

    The mesenchymal-epithelial transition factor (c-Met) is a receptor tyrosine kinase with hepatocyte growth factor (HGF) as its only high-affinity ligand. Aberrant activation of c-Met is associated with many human malignancies, including hepatocellular carcinoma (HCC). We investigated the in vivo antitumor and antimetastatic efficacy of the c-Met inhibitor MSC2156119J (EMD 1214063) in patient-derived tumor explants. BALB/c nude mice were inoculated with MHCC97H cells or with tumor fragments of 10 patient-derived primary liver cancer explants selected according to c-Met/HGF expression levels. MSC2156119J (10, 30, and 100 mg/kg) and sorafenib (50 mg/kg) were administered orally as single-agent treatment or in combination, with vehicle as control. Tumor response, metastases formation, and alpha fetoprotein (AFP) levels were measured. MSC2156119J inhibited tumor growth and induced complete regression in mice bearing subcutaneous and orthotopic MHCC97H tumors. AFP levels were undetectable after 5 weeks of MSC2156119J treatment, and the number of metastatic lung foci was reduced. Primary liver explant models with strong c-Met/HGF activation showed increased responsiveness to MSC2156119J, with MSC2156119J showing similar or superior activity to sorafenib. Tumors characterized by low c-Met expression were less sensitive to MSC2156119J. MSC2156119J was better tolerated than sorafenib, and combination therapy did not improve efficacy. These findings indicate that selective c-Met/HGF inhibition with MSC2156119J is associated with marked regression of c-Met high-expressing tumors, supporting its clinical development as an antitumor treatment for HCC patients with active c-Met signaling.

  5. Chronic lymphocytic leukemia nurse-like cells express hepatocyte growth factor receptor (c-MET) and indoleamine 2,3-dioxygenase and display features of immunosuppressive type 2 skewed macrophages

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    Giannoni, Paolo; Pietra, Gabriella; Travaini, Giorgia; Quarto, Rodolfo; Shyti, Genti; Benelli, Roberto; Ottaggio, Laura; Mingari, Maria Cristina; Zupo, Simona; Cutrona, Giovanna; Pierri, Ivana; Balleari, Enrico; Pattarozzi, Alessandra; Calvaruso, Marco; Tripodo, Claudio; Ferrarini, Manlio; de Totero, Daniela

    2014-01-01

    Hepatocyte growth factor, produced by stromal and follicular dendritic cells, and present at high concentrations in the sera of patients with chronic lymphocytic leukemia, prolongs the survival of leukemic B cells by interacting with their receptor, c-MET. It is, however, unknown whether hepatocyte growth factor influences microenvironmental cells, such as nurse-like cells, which deliver survival signals to the leukemic clone. We evaluated the expression of c-MET on nurse-like cells and monocytes from patients with chronic lymphocytic leukemia and searched for phenotypic/functional features supposed to be influenced by the hepatocyte growth factor/c-MET interaction. c-MET is expressed at high levels on nurse-like cells and at significantly higher levels than normal on monocytes from patients. Moreover, the hepatocyte growth factor/c-MET interaction activates STAT3TYR705 phosphorylation in nurse-like cells. Indoleamine 2,3-dioxygenase, an enzyme modulating T-cell proliferation and induced on normal monocytes after hepatocyte growth factor treatment, was detected together with interleukin-10 on nurse-like cells, and on freshly-prepared patients’ monocytes. Immunohistochemical/immunostaining analyses demonstrated the presence of c-MET+ and indoleamine 2,3-dioxygenase+ cells in lymph node biopsies, co-expressed with CD68 and vimentin. Furthermore nurse-like cells and chronic lymphocytic monocytes significantly inhibited T-cell proliferation, prevented by anti-transforming growth factor beta and interleukin-10 antibodies and indoleamine 2,3-dioxygenase inhibitors, and supported CD4+CD25high+/FOXP3+ T regulatory cell expansion. We suggest that nurse-like cells display features of immunosuppressive type 2 macrophages: higher hepatocyte growth factor levels, produced by leukemic or other microenvironmental surrounding cells, may cooperate to induce M2 polarization. Hepatocyte growth factor may thus have a dual pathophysiological role: directly through enhancement of

  6. Expression of hepatocyte growth factor and its receptor c-Met in lens-induced myopia in guinea pigs

    Institute of Scientific and Technical Information of China (English)

    LI Xiu-juan; YANG Xiao-peng; WAN Guang-ming; WANG Yu-ying; ZHANG Jin-song

    2013-01-01

    Background Myopia is a common disorder and the incidence has increased yearly,but its pathogenesis remains unclear.The aim of this study was to investigate the possible role of hepatocyte growth factor (HGF) and its receptor c-Met in the development of lens-induced myopia in guinea pigs.Methods Sixty one-week-old guinea pigs were chosen.The right eyes were treated with-10.0 diopters (D) lenses as the lens-induced myopia group; the left eyes remained untreated as the control group.Six weeks later,refractive status and axial length were determined by streak retinoscopy and A-scan ultrasonography,respectively.The guinea pigs were killed and both eyes collected.Morphological changes were observed by hematoxylin and eosin staining.The expression levels of HGF,c-Met,and matrix metalloproteinase 2 (MMP-2) mRNA and protein in the posterior sclera were analyzed by RT-PCR and Western blotting,respectively.Results The lens-induced myopia group became myopic with a significant increase in axial length and a significant decrease in refraction.Compared with the control group,the posterior retina and sclera were thinner in the lens-induced myopia group.The expression levels of HGF and MMP-2 mRNA and protein and of phosphorylated c-Met protein were significantly higher in the posterior sclera of the lens-induced myopia group than in the control group (all P <0.05).In the lens-induced myopia group,the expression level of MMP-2 in the posterior sclera positively correlated with the expression level of HGF (r=0.902,P <0.05) and phosphorylated c-Met (r=0.885,P <0.05).Conclusion HGF/c-Met might play a role in the development of lens-induced myopia in guinea pigs by upregulating the expression of MMP-2.

  7. Host-pathogen systems biology: logical modelling of hepatocyte growth factor and Helicobacter pylori induced c-Met signal transduction

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    Kähne Thilo

    2008-01-01

    Full Text Available Abstract Background The hepatocyte growth factor (HGF stimulates mitogenesis, motogenesis, and morphogenesis in a wide range of tissues, including epithelial cells, on binding to the receptor tyrosine kinase c-Met. Abnormal c-Met signalling contributes to tumour genesis, in particular to the development of invasive and metastatic phenotypes. The human microbial pathogen Helicobacter pylori can induce chronic gastritis, peptic ulceration and more rarely, gastric adenocarcinoma. The H. pylori effector protein cytotoxin associated gene A (CagA, which is translocated via a type IV secretion system (T4SS into epithelial cells, intracellularly modulates the c-Met receptor and promotes cellular processes leading to cell scattering, which could contribute to the invasiveness of tumour cells. Using a logical modelling framework, the presented work aims at analysing the c-Met signal transduction network and how it is interfered by H. pylori infection, which might be of importance for tumour development. Results A logical model of HGF and H. pylori induced c-Met signal transduction is presented in this work. The formalism of logical interaction hypergraphs (LIH was used to construct the network model. The molecular interactions included in the model were all assembled manually based on a careful meta-analysis of published experimental results. Our model reveals the differences and commonalities of the response of the network upon HGF and H. pylori induced c-Met signalling. As another important result, using the formalism of minimal intervention sets, phospholipase Cγ1 (PLCγ1 was identified as knockout target for repressing the activation of the extracellular signal regulated kinase 1/2 (ERK1/2, a signalling molecule directly linked to cell scattering in H. pylori infected cells. The model predicted only an effect on ERK1/2 for the H. pylori stimulus, but not for HGF treatment. This result could be confirmed experimentally in MDCK cells using a specific

  8. Inhibition of c-Met activation sensitizes osteosarcoma cells to cisplatin via suppression of the PI3K-Akt signaling.

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    Wang, Kelai; Zhuang, Yan; Liu, Chunlan; Li, Yang

    2012-10-01

    Osteosarcoma is a common malignant bone tumor. Cisplatin (CDDP) achieves a high response rate in osteosarcoma. However, osteosarcoma usually exhibits cisplatin resistance. Many members of receptor tyrosine kinases (RTKs)(1) have been demonstrated to be overexpressed and constitutively activated in various tumors including osteosarcoma, resulting in malignant progression and insensitivity to chemotherapy. Hepatocyte growth factor receptor (HGFR/c-Met) also appears overexpressed and activated in osteosarcoma cells. Nevertheless, which role of c-Met activation in cisplatin efficacy against osteosarcoma cells remains still elusive. This study found that inhibition of c-Met activity by PHA-665752 or blockade of the interaction of autocrined HGF with c-Met with neutralizing anti-HGF antibody promoted cisplatin efficacy in osteosarcoma cells, while addition of recombinant human HGF (rh-HGF) counteracts cisplatin cytotoxicity. Specifically, we demonstrated that inhibition of c-Met activity led to suppression of the PI3K-Akt pathway, thus enhancing cisplatin chemosensitivity. Our study clearly suggests that inhibition of c-Met activity can effectively sensitize osteosarcoma cells to cisplatin via suppression of the PI3K-Akt signaling.

  9. Expression of the proto-oncogenes c-met and c-kit and their ligands, hepatocyte growth factor/scatter factor and stem cell factor, in SCLC cell lines and xenografts

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    Rygaard, K; Nakamura, T; Spang-Thomsen, M

    1993-01-01

    We examined a panel of 25 small cell lung cancer (SCLC) cell lines and nude mouse xenografts for expression of the proto-oncogenes c-met and c-kit, and for expression of the corresponding ligands, hepatocyte growth factor (HGF) (also known as scatter factor (SF)), and stem cell factor (SCF......), respectively. Expression of mRNA was detected by Northern blotting, and c-met and c-kit protein expression was detected by Western blotting and immunocytochemistry. c-met and c-kit mRNA was expressed in 22 of the examined cell lines or xenografts, and coexpression of the two proto-oncogenes was observed in 20...... tumours. Expression of c-met and c-kit protein paralleled in the mRNA expression. HGF/SF mRNA was expressed in two of the examined tumours, and only one of these also expressed the c-met proto-oncogene. SCF mRNA was expressed in 19 of the examined tumours, and in 18 of these coexpression of c-kit and SCF...

  10. c-MET receptor tyrosine kinase as a molecular target in advanced hepatocellular carcinoma

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    Granito A

    2015-04-01

    Full Text Available Alessandro Granito,1 Elena Guidetti,1 Laura Gramantieri2,3 1Dipartimento di Scienze Mediche e Chirurgiche Università di Bologna, Bologna, Italy; 2Dipartimento dell'Apparato Digerente, Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy; 3Centro di Ricerca Biomedica Applicata (CRBA, Azienda Ospedaliero-Universitaria Policlinico S Orsola-Malpighi e Università di Bologna, Bologna, Italy Abstract: c-MET is the membrane receptor for hepatocyte growth factor (HGF, also known as scatter factor or tumor cytotoxic factor, a mitogenic growth factor for hepatocytes. HGF is mainly produced by cells of mesenchymal origin and it mainly acts on neighboring epidermal and endothelial cells, regulating epithelial growth and morphogenesis. HGF/MET signaling has been identified among the drivers of tumorigenesis in human cancers. As such, c-MET is a recognized druggable target, and against it, targeted agents are currently under clinical investigation. c-MET overexpression is a common event in a wide range of human malignancies, including gastric, lung, breast, ovary, colon, kidney, thyroid, and liver carcinomas. Despite c-MET overexpression being reported by a large majority of studies, no evidence for a c-MET oncogenic addiction exists in hepatocellular carcinoma (HCC. In particular, c-MET amplification is a rare event, accounting for 4%–5% of cases while no mutation has been identified in c-MET oncogene in HCC. Thus, the selection of patient subgroups more likely to benefit from c-MET inhibition is challenging. Notwithstanding, c-MET overexpression was reported to be associated with increased metastatic potential and poor prognosis in patients with HCC, providing a rationale for its therapeutic inhibition. Here we summarize the role of activated HGF/MET signaling in HCC, its prognostic relevance, and the implications for therapeutic approaches in HCC. Keywords: hepatocellular carcinoma, c-MET, clinical trials

  11. HGF/C-Met在舌部鳞状细胞癌的表达及其临床意义%Expression of Hepatocyte Growth Factor (HGF) and c-Met in Squamous Cell Carcinoma of the Oral Tongue(SCCOT)

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    陈仲伟; 徐冬贵; 朱李军; 王启朋; 冯航; 江穗

    2013-01-01

    目的:探讨肝细胞生长因子及其受体C-Met蛋白在舌鳞癌中的表达与其临床病理特征之间的关系.方法:通过免疫组化法检测10例正常舌组织、14例舌癌前病变及63例舌鳞癌中肝细胞生长因子、C-Met的表达,数据通过SPSS13.0统计软件非参数秩和检验统计.结果:肝细胞生长因子和C-Met在舌癌、舌癌前病变及正常舌组织的阳性表达率分别为84.1%、57.1%、40.0%和76.2%、35.7%、20.0%,其表达差异均具有统计学意义(P<0.05).在中、低分化组(90.3%)及有淋巴结转移组(100%)舌鳞癌中肝细胞生长因子的阳性表达率显著高于高分化组(78.1%)及无转移淋巴结组(76.7%);在Ⅲ、Ⅳ期(82.1%)及有淋巴结转移组(85.0%)的舌鳞癌中C-Met阳性表达率显著高于Ⅰ、Ⅱ期(71.4%)及无转移淋巴结组(72.1%),表达差异均具有统计学意义(p<0.05);63例舌癌组织切片中46例HGF及C-Met都有阳性表达,其在舌鳞状细胞癌中的表达显著正相关(P<0.01).结论:过度表达的HGF/C-Met可作为判断舌鳞状细胞癌生物学行为、恶性潜能和预测淋巴结转移趋势的参考指标.%Objective: To evaluate the relationship of the expression of hepatocyte growth factor (HGF)/c-Met and clinical and pathologic characteristics of patients with squamous cell carcinoma of the oral tongue(SCCOT). Methods; Tumors from 63 patients with SCCOT, precancerous lesions of tongue from 14 patients and normal tissues of the tongue from 10 patients were evaluated for the expression of HGF and c -Met by immunohistochemis-try. Results: The positive rates of HGF and c-Met immunostaining in SCCOT were 84. 1% and 76. 2% respectively, which was significantly higher than that of the precancerous and normal groups (57. 1 % ,35. 7% and 40. 0% ,20. 0%). The HGF/c-Met staining was significantly correlated with lymph node metastasis(P<0. 05), tumor classification P<0. 05) and TNM pathologic stages. There was a

  12. Isolation and characterization of anti c-met single chain fragment variable (scFv) antibodies.

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    Qamsari, Elmira Safaie; Sharifzadeh, Zahra; Bagheri, Salman; Riazi-Rad, Farhad; Younesi, Vahid; Abolhassani, Mohsen; Ghaderi, Sepideh Safaei; Baradaran, Behzad; Somi, Mohammad Hossein; Yousefi, Mehdi

    2017-12-01

    The receptor tyrosine kinase (RTK) Met is the cell surface receptor for hepatocyte growth factor (HGF) involved in invasive growth programs during embryogenesis and tumorgenesis. There is compelling evidence suggesting important roles for c-Met in colorectal cancer proliferation, migration, invasion, angiogenesis, and survival. Hence, a molecular inhibitor of an extracellular domain of c-Met receptor that blocks c-Met-cell surface interactions could be of great thera-peutic importance. In an attempt to develop molecular inhibitors of c-Met, single chain variable fragment (scFv) phage display libraries Tomlinson I + J against a specific synthetic oligopeptide from the extracellular domain of c-Met receptor were screened; selected scFv were then characterized using various immune techniques. Three c-Met specific scFv (ES1, ES2, and ES3) were selected following five rounds of panning procedures. The scFv showed specific binding to c-Met receptor, and significantly inhibited proliferation responses of a human colorectal carcinoma cell line (HCT-116). Moreover, anti- apoptotic effects of selected scFv antibodies on the HCT-116 cell line were also evaluated using Annexin V/PI assays. The results demonstrated rates of apoptotic cell death of 46.0, 25.5, and 37.8% among these cells were induced by use of ES1, ES2, and ES3, respectively. The results demonstrated ability to successfully isolate/char-acterize specific c-Met scFv that could ultimately have a great therapeutic potential in immuno-therapies against (colorectal) cancers.

  13. MicroRNA-449a is downregulated in non-small cell lung cancer and inhibits migration and invasion by targeting c-Met.

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    Wenting Luo

    Full Text Available MicroRNA-449a is expressed at a low level in several tumors and cancer cell lines, and induces G1 arrest, apoptosis, and senescence. To identify the function of miR-449a in non-small cell lung cancer (NSCLC, we discussed the potential relevance of miR-449a to clinicopathological characteristics and prognosis in NSCLC. We also investigated the impact of miR-449a on migration and invasion in NSCLC cells. The expression of miR-449a in NSCLC tissues and cell lines was detected using RT-qPCR. In vitro, gain-of-function, loss-of-function experiments, and fluorescence assays were performed to identify the potential target of miR-449a and the function of miR-449a in NSCLC cells. MiR-449a was downregulated in both NSCLC tissues and cell lines. Moreover, a low expression level of miR-449a appeared to be correlated with lymph node metastasis and poor survival. In vitro, miR-449 regulated cell migration and invasion in NSCLC cells as a potential tumor suppressor, at least in part by targeting c-Met. Furthermore, reciprocal expression of miR-449a and c-Met was shown in NSCLC tissue samples. This study indicates that miR-449a might be associated with NSCLC progression, and suggests a crucial role for miR-449a in NSCLC.

  14. Efficacy of c-Met inhibitor for advanced prostate cancer

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    Christensen James G

    2010-10-01

    Full Text Available Abstract Background Aberrant expression of HGF/SF and its receptor, c-Met, often correlates with advanced prostate cancer. Our previous study showed that expression of c-Met in prostate cancer cells was increased after attenuation of androgen receptor (AR signalling. This suggested that current androgen ablation therapy for prostate cancer activates c-Met expression and may contribute to development of more aggressive, castration resistant prostate cancer (CRPC. Therefore, we directly assessed the efficacy of c-Met inhibition during androgen ablation on the growth and progression of prostate cancer. Methods We tested two c-Met small molecule inhibitors, PHA-665752 and PF-2341066, for anti-proliferative activity by MTS assay and cell proliferation assay on human prostate cancer cell lines with different levels of androgen sensitivity. We also used renal subcapsular and castrated orthotopic xenograft mouse models to assess the effect of the inhibitors on prostate tumor formation and progression. Results We demonstrated a dose-dependent inhibitory effect of PHA-665752 and PF-2341066 on the proliferation of human prostate cancer cells and the phosphorylation of c-Met. The effect on cell proliferation was stronger in androgen insensitive cells. The c-Met inhibitor, PF-2341066, significantly reduced growth of prostate tumor cells in the renal subcapsular mouse model and the castrated orthotopic mouse model. The effect on cell proliferation was greater following castration. Conclusions The c-Met inhibitors demonstrated anti-proliferative efficacy when combined with androgen ablation therapy for advanced prostate cancer.

  15. FAK kinase activity is required for the progression of c-Met/β-catenin-driven HCC

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    Shang, Na; Arteaga, Maribel; Zaidi, Ali; Cotler, Scott J.; Breslin, Peter; Ding, Xianzhong; Kuo, Paul; Nishimura, Michael; Zhang, Jiwang; Qiu, Wei

    2016-01-01

    Background & Aims There is an urgent need to develop new and more effective therapeutic strategies and agents to treat hepatocellular carcinoma (HCC). We have recently found that deletion of Fak in hepatocytes before tumors form inhibits tumor development and prolongs survival of animals in a c-Met (MET)/β-catenin (CAT)-driven HCC mouse model. However, it has yet to be determined whether FAK expression in hepatocytes promotes MET/CAT-induced HCC progression after tumor initiation. In addition, it remains unclear whether FAK promotes HCC development through its kinase activity. Methods We generated hepatocyte-specific inducible Fak-deficient mice (Alb-creERT2; Fakflox/flox) to examine the role of FAK in HCC progression. We re-expressed wild-type and mutant FAK in Fak-deficient mice to determine FAK’s kinase activity in HCC development. We also examined the efficacy of a FAK kinase inhibitor PF-562271 on HCC inhibition. Results We found that deletion of Fak after tumors form significantly repressed MET/CAT-induced tumor progression. Ectopic FAK expression restored HCC formation in hepatocyte-specific Fak-deficient mice. However, overexpression of a FAK kinase-dead mutant led to reduced tumor load compared to mice which express wild-type FAK. Furthermore, PF-562271 significantly suppressed progression of MET/CAT-induced HCC. Conclusion Fak kinase activity is important for MET/CAT-induced HCC progression. Inhibiting FAK kinase activity provides a potential therapeutic strategy to treat HCC. PMID:27142958

  16. Cardiotoxin III Inhibits Hepatocyte Growth Factor-Induced Epithelial-Mesenchymal Transition and Suppresses Invasion of MDA-MB-231 Cells.

    Science.gov (United States)

    Tsai, Pei-Chien; Fu, Yaw-Syan; Chang, Long-Sen; Lin, Shinne-Ren

    2016-01-01

    The epithelial-mesenchymal transition (EMT) is the first step required for breast cancer to initiate metastasis. In this study, hepatocyte growth factor (HGF) was used as a metastatic inducer of MDA-MB-231 cells. Cardiotoxin III (CTX III) inhibited HGF-induced morphological changes and upregulation of E-cadherin with the concomitant decrease in N-cadherin and Vimentin protein levels, resulting in inhibition of cell migration and invasion. CTX III-induced downregulation of transcription factors, Snail, Twist, and Slug, in MDA-MB-231 cells. CTX III suppressed c-Met phosphorylation and downstream activation of phosphatidylinositol 3-kinase (PI3K)/Akt and extracellular signal-regulated kinase (ERK)1/2. The c-Met specific inhibitor PHA665752 attenuated ERK1/2 and Akt phosphorylation, cell migration and invasion, as well as the expressional changes of EMT markers induced by HGF. Taken together, our data suggest that CTX III suppresses HGF/c-Met-induced cell migration and invasion by reversing EMT, which involves the inactivation of the HGF/c-Met-mediated ERK1/2 and PI3K/Akt pathways in MDA-MB-231 cells.

  17. c-Met in pancreatic cancer stem cells: Therapeutic implications

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    Marta Herreros-Villanueva; Aizpea Zubia-Olascoaga; Luis Bujanda

    2012-01-01

    Pancreatic cancer is the deadliest solid cancer and currently the fourth most frequent cause of cancer-related deaths.Emerging evidence suggests that cancer stem cells (CSCs) play a crucial role in the development and progression of this disease.The identification of CSC markers could lead to the development of new therapeutic targets.In this study,the authors explore the functional role of c-Met in pancreatic CSCs,by analyzing self-renewal with sphere assays and tumorigenicity capacity in NOD SCID mice.They concluded that c-Met is a novel marker for identifying pancreatic CSCs and c-Methigh in a higher tumorigenic cancer cell population.Inhibition of c-Met with XL184 blocks self-renewal capacity in pancreatic CSCs.In pancreatic tumors established in NOD SCID mice,c-Met inhibition slowed tumor growth and reduced the population of CSCs,along with preventing the development of metastases.

  18. Impact of Cell-surface Antigen Expression on Target Engagement and Function of an Epidermal Growth Factor Receptor × c-MET Bispecific Antibody*

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    Jarantow, Stephen W.; Bushey, Barbara S.; Pardinas, Jose R.; Boakye, Ken; Lacy, Eilyn R.; Sanders, Renouard; Sepulveda, Manuel A.; Moores, Sheri L.; Chiu, Mark L.

    2015-01-01

    The efficacy of engaging multiple drug targets using bispecific antibodies (BsAbs) is affected by the relative cell-surface protein levels of the respective targets. In this work, the receptor density values were correlated to the in vitro activity of a BsAb (JNJ-61186372) targeting epidermal growth factor receptor (EGFR) and hepatocyte growth factor receptor (c-MET). Simultaneous binding of the BsAb to both receptors was confirmed in vitro. By using controlled Fab-arm exchange, a set of BsAbs targeting EGFR and c-MET was generated to establish an accurate receptor quantitation of a panel of lung and gastric cancer cell lines expressing heterogeneous levels of EGFR and c-MET. EGFR and c-MET receptor density levels were correlated to the respective gene expression levels as well as to the respective receptor phosphorylation inhibition values. We observed a bias in BsAb binding toward the more highly expressed of the two receptors, EGFR or c-MET, which resulted in the enhanced in vitro potency of JNJ-61186372 against the less highly expressed target. On the basis of these observations, we propose an avidity model of how JNJ-61186372 engages EGFR and c-MET with potentially broad implications for bispecific drug efficacy and design. PMID:26260789

  19. Impact of Cell-surface Antigen Expression on Target Engagement and Function of an Epidermal Growth Factor Receptor × c-MET Bispecific Antibody.

    Science.gov (United States)

    Jarantow, Stephen W; Bushey, Barbara S; Pardinas, Jose R; Boakye, Ken; Lacy, Eilyn R; Sanders, Renouard; Sepulveda, Manuel A; Moores, Sheri L; Chiu, Mark L

    2015-10-09

    The efficacy of engaging multiple drug targets using bispecific antibodies (BsAbs) is affected by the relative cell-surface protein levels of the respective targets. In this work, the receptor density values were correlated to the in vitro activity of a BsAb (JNJ-61186372) targeting epidermal growth factor receptor (EGFR) and hepatocyte growth factor receptor (c-MET). Simultaneous binding of the BsAb to both receptors was confirmed in vitro. By using controlled Fab-arm exchange, a set of BsAbs targeting EGFR and c-MET was generated to establish an accurate receptor quantitation of a panel of lung and gastric cancer cell lines expressing heterogeneous levels of EGFR and c-MET. EGFR and c-MET receptor density levels were correlated to the respective gene expression levels as well as to the respective receptor phosphorylation inhibition values. We observed a bias in BsAb binding toward the more highly expressed of the two receptors, EGFR or c-MET, which resulted in the enhanced in vitro potency of JNJ-61186372 against the less highly expressed target. On the basis of these observations, we propose an avidity model of how JNJ-61186372 engages EGFR and c-MET with potentially broad implications for bispecific drug efficacy and design.

  20. A novel rabbit anti-hepatocyte growth factor monoclonal neutralizing antibody inhibits tumor growth in prostate cancer cells and mouse xenografts

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Yanlan; Chen, Yicheng; Ding, Guoqing; Wang, Mingchao; Wu, Haiyang; Xu, Liwei; Rui, Xuefang; Zhang, Zhigen, E-mail: srrshurology@163.com

    2015-08-14

    The hepatocyte growth factor and its receptor c-Met are correlated with castration-resistance in prostate cancer. Although HGF has been considered as an attractive target for therapeutic antibodies, the lack of cross-reactivity of monoclonal antibodies with human/mouse HGFs is a major obstacle in preclinical developments. We generated a panel of anti-HGF RabMAbs either blocking HGF/c-Met interaction or inhibiting c-Met phosphorylation. We selected one RabMAb with mouse cross-reactivity and demonstrated that it blocked HGF-stimulated downstream activation in PC-3 and DU145 cells. Anti-HGF RabMAb inhibited not only the growth of PC-3 cells but also HGF-dependent proliferation in HUVECs. We further demonstrated the efficacy and potency of the anti-HGF RabMAb in tumor xenograft mice models. Through these in vitro and in vivo experiments, we explored a novel therapeutic antibody for advanced prostate cancer. - Highlights: • HGF is an attractive target for castration-refractory prostate cancer. • We generated and characterized a panel of anti-HGF rabbit monoclonal antibodies. • More than half of these anti-HGF RabMAbs was cross-reactive with mouse HGF. • Anti-HGF RabMAb blocks HGF-stimulated phosphorylation and cell growth in vitro. • Anti-HGF RabMAb inhibits tumor growth and angiogenesis in xenograft mice.

  1. Curcumin inhibits activation of TRPM2 channels in rat hepatocytes

    Directory of Open Access Journals (Sweden)

    E. Kheradpezhouh

    2016-04-01

    Full Text Available Oxidative stress is a hallmark of many liver diseases including viral and drug-induced hepatitis, ischemia-reperfusion injury, and non-alcoholic steatohepatitis. One of the consequences of oxidative stress in the liver is deregulation of Ca2+ homeostasis, resulting in a sustained elevation of the free cytosolic Ca2+ concentration ([Ca2+]c in hepatocytes, which leads to irreversible cellular damage. Recently it has been shown that liver damage induced by paracetamol and subsequent oxidative stress is, in large part, mediated by Ca2+ entry through Transient Receptor Potential Melastatin 2 (TRPM2 channels. Involvement of TRPM2 channels in hepatocellular damage induced by oxidative stress makes TRPM2 a potential therapeutic target for treatment of a range of oxidative stress-related liver diseases. We report here the identification of curcumin ((1E,6E-1,7-bis(4-hydroxy-3-methoxyphenyl-1,6-heptadiene-3,5-dione, a natural plant-derived polyphenol in turmeric spice, as a novel inhibitor of TRPM2 channel. Presence of 5 µM curcumin in the incubation medium prevented the H2O2- and paracetamol-induced [Ca2+]c rise in rat hepatocytes. Furthermore, in patch clamping experiments incubation of hepatocytes with curcumin inhibited activation of TRPM2 current by intracellular ADPR with IC50 of approximately 50 nM. These findings enhance understanding of the actions of curcumin and suggest that the known hepatoprotective properties of curcumin are, at least in part, mediated through inhibition of TRPM2 channels.

  2. LoVo colon cancer cells resistant to oxaliplatin overexpress c-MET and VEGFR-1 and respond to VEGF with dephosphorylation of c-MET.

    Science.gov (United States)

    Mezquita, Belén; Pineda, Estela; Mezquita, Jovita; Mezquita, Pau; Pau, Montserrat; Codony-Servat, Jordi; Martínez-Balibrea, Eva; Mora, Conchi; Maurel, Joan; Mezquita, Cristóbal

    2016-05-01

    Oxaliplatin-resistant LoVo colon cancer cells overexpressing c-MET and VEGFR-1 were selected to study several signaling pathways involved in chemoresistance, as well as the effect of increasing amounts of VEGF in the regulation of c-MET. In comparison with chemosensitive LoVo colon cancer cells, oxaliplatin-resistant cells (LoVoR) overexpress and phosphorylate c-MET, upregulate the expression of transmembrane and soluble VEGFR-1 and, unexpectedly, downregulate VEGF. In addition, LoVoR cells activate other transduction pathways involved in chemoresistance such as Akt, β-catenin-TCF4 and E-cadherin. While c-MET is phosphorylated in LoVoR cells expressing low levels of VEGF, c-MET phosphorylation decreases when recombinant VEGF is added into the culture medium. Inhibition of c-MET by VEGF is mediated by VEGFR-1, since phosphorylation of c-MET in the presence of VEGF is restored after silencing VEGFR-1. Dephosphorylation of c-MET by VEGF suggests that tumors coexpressing VEGFR-1 and c-MET may activate c-MET as a result of anti-VEGF therapy.

  3. A novel antagonist anti-cMet antibody with antitumor activities targeting both ligand-dependent and ligand-independent c-Met receptors.

    Science.gov (United States)

    Gonzalez, Alexandra; Broussas, Matthieu; Beau-Larvor, Charlotte; Haeuw, Jean-François; Boute, Nicolas; Robert, Alain; Champion, Thierry; Beck, Alain; Bailly, Christian; Corvaïa, Nathalie; Goetsch, Liliane

    2016-10-15

    c-Met is a prototypic member of a sub-family of RTKs. Inappropriate c-Met activation plays a crucial role in tumor formation, proliferation and metastasis. Using a key c-Met dimerization assay, a set of 12 murine whole IgG1 monoclonal antibodies was selected and a lead candidate, m224G11, was humanized by CDR-grafting and engineered to generate a divalent full antagonist humanized IgG1 antibody, hz224G11. Neither m224G11 nor hz224G11 bind to the murine c-Met receptor. Their antitumor activity was investigated in vitro in a set of experiments consistent with the reported pleiotropic effects mediated by c-Met and, in vivo, using several human tumor xenograft models. Both m224G11 and hz224G11 exhibited nanomolar affinities for the receptor and inhibited HGF binding, c-Met phosphorylation, and receptor dimerization in a similar fashion, resulting in a profound inhibition of all c-Met functions in vitro. These effects were presumably responsible for the inhibition of c-Met's major functions including cell proliferation, migration, invasion scattering, morphogenesis and angiogenesis. In addition to these in vitro properties, hz224G11 dramatically inhibits the growth of autocrine, partially autophosphorylated and c-Met amplified cell lines in vivo. Pharmacological studies performed on Hs746T gastric cancer xenografts demonstrate that hz224G11 strongly downregulates c-Met expression and phosphorylation. It also decreases the tumor mitotic index (Ki67) and induces apoptosis. Taken together, the in vitro and in vivo data suggest that hz224G11 is a promising candidate for the treatment of tumors. This antibody, now known as ABT-700 and currently in Phase I clinical trials, may provide a novel therapeutic approach to c-Met-expressing cancers.

  4. Fibulin-3 negatively regulates ALDH1 via c-MET suppression and increases γ-radiation-induced sensitivity in some pancreatic cancer cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Kim, In-Gyu, E-mail: igkim@kaeri.re.kr [Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Department of Radiation Biotechnology and Applied Radioisotope, Korea University of Science and Technology (UST), 989-111 Daedeok-daero, Yusong-gu, Daejeon 305-353 (Korea, Republic of); Lee, Jae-Ha [Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Department of Radiation Biotechnology and Applied Radioisotope, Korea University of Science and Technology (UST), 989-111 Daedeok-daero, Yusong-gu, Daejeon 305-353 (Korea, Republic of); Kim, Seo-Yoen; Kim, Jeong-Yul [Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Cho, Eun-Wie [Epigenomics Research Center, Korea Research Institute of Bioscience and Biotechnology, 125 Gwahak-ro, Yuseong-gu, Daejeon 305-806 (Korea, Republic of)

    2014-11-21

    Highlights: • FBLN-3 gene was poorly expressed in some pancreatic cancer lines. • FBLN-3 promoter region was highly methylated in some pancreatic cancer cell lines. • FBLN-3 inhibited c-MET activation and expression and reduced cellular level of ALDH1. • FBLN-3/c-Met/ALDH1 axis modulates stemness and EMT in pancreatic cancer cells. - Abstract: Fibulin-3 (FBLN-3) has been postulated to be either a tumor suppressor or promoter depending on the cell type, and hypermethylation of the FBLN-3 promoter is often associated with human disease, especially cancer. We report that the promoter region of the FBLN-3 was significantly methylated (>95%) in some pancreatic cancer cell lines and thus FBLN-3 was poorly expressed in pancreatic cancer cell lines such as AsPC-1 and MiaPaCa-2. FBLN-3 overexpression significantly down-regulated the cellular level of c-MET and inhibited hepatocyte growth factor-induced c-MET activation, which were closely associated with γ-radiation resistance of cancer cells. Moreover, we also showed that c-MET suppression or inactivation decreased the cellular level of ALDH1 isozymes (ALDH1A1 or ALDH1A3), which serve as cancer stem cell markers, and subsequently induced inhibition of cell growth in pancreatic cancer cells. Therefore, forced overexpression of FBLN-3 sensitized cells to cytotoxic agents such as γ-radiation and strongly inhibited the stemness and epithelial to mesenchymal transition (EMT) property of pancreatic cancer cells. On the other hand, if FBLN3 was suppressed in FBLN-3-expressing BxPC3 cells, the results were opposite. This study provides the first demonstration that the FBLN-3/c-MET/ALDH1 axis in pancreatic cancer cells partially modulates stemness and EMT as well as sensitization of cells to the detrimental effects of γ-radiation.

  5. The clinical and functional significance of c-Met in breast cancer: a review.

    Science.gov (United States)

    Ho-Yen, Colan M; Jones, J Louise; Kermorgant, Stephanie

    2015-04-08

    c-Met is a receptor tyrosine kinase that upon binding of its ligand, hepatocyte growth factor (HGF), activates downstream pathways with diverse cellular functions that are important in organ development and cancer progression. Anomalous c-Met signalling has been described in a variety of cancer types, and the receptor is regarded as a novel therapeutic target. In breast cancer there is a need to develop new treatments, particularly for the aggressive subtypes such as triple-negative and basal-like cancer, which currently lack targeted therapy. Over the last two decades, much has been learnt about the functional role of c-Met signalling in different models of breast development and cancer. This work has been complemented by clinical studies, establishing the prognostic significance of c-Met in tissue samples of breast cancer. While the clinical trials of anti-c-Met therapy in advanced breast cancer progress, there is a need to review the existing evidence so that the potential of these treatments can be better appreciated. The aim of this article is to examine the role of HGF/c-Met signalling in in vitro and in vivo models of breast cancer, to describe the mechanisms of aberrant c-Met signalling in human tissues, and to give a brief overview of the anti-c-Met therapies currently being evaluated in breast cancer patients. We will show that the HGF/c-Met pathway is associated with breast cancer progression and suggest that there is a firm basis for continued development of anti-c-Met treatment, particularly for patients with basal-like and triple-negative breast cancer.

  6. Blood vessel endothelium-directed tumor cell streaming in breast tumors requires the HGF/C-Met signaling pathway.

    Science.gov (United States)

    Leung, E; Xue, A; Wang, Y; Rougerie, P; Sharma, V P; Eddy, R; Cox, D; Condeelis, J

    2016-11-28

    During metastasis to distant sites, tumor cells migrate to blood vessels. In vivo, breast tumor cells utilize a specialized mode of migration known as streaming, where a linear assembly of tumor cells migrate directionally towards blood vessels on fibronectin-collagen I-containing extracellular matrix (ECM) fibers in response to chemotactic signals. We have successfully reconstructed tumor cell streaming in vitro by co-plating tumors cells, macrophages and endothelial cells on 2.5 μm thick ECM-coated micro-patterned substrates. We found that tumor cells and macrophages, when plated together on the micro-patterned substrates, do not demonstrate sustained directional migration in only one direction (sustained directionality) but show random bi-directional walking. Sustained directionality of tumor cells as seen in vivo was established in vitro when beads coated with human umbilical vein endothelial cells were placed at one end of the micro-patterned 'ECM fibers' within the assay. We demonstrated that these endothelial cells supply the hepatocyte growth factor (HGF) required for the chemotactic gradient responsible for sustained directionality. Using this in vitro reconstituted streaming system, we found that directional streaming is dependent on, and most effectively blocked, by inhibiting the HGF/C-Met signaling pathway between endothelial cells and tumor cells. Key observations made with the in vitro reconstituted system implicating C-Met signaling were confirmed in vivo in mammary tumors using the in vivo invasion assay and intravital multiphoton imaging of tumor cell streaming. These results establish HGF/C-Met as a central organizing signal in blood vessel-directed tumor cell migration in vivo and highlight a promising role for C-Met inhibitors in blocking tumor cell streaming and metastasis in vivo, and for use in human trials.Oncogene advance online publication, 28 November 2016; doi:10.1038/onc.2016.421.

  7. Indazoles as potential c-Met inhibitors: design, synthesis and molecular docking studies.

    Science.gov (United States)

    Ye, Lianbao; Ou, Xiaomin; Tian, Yuanxin; Yu, Bangwei; Luo, Yan; Feng, Binghong; Lin, Hansen; Zhang, Jiajie; Wu, Shuguang

    2013-07-01

    Deregulation of the receptor tyrosine kinase c-Met has been implicated in several human cancers and is considered as an attractive target for small molecule drug discovery. In this study, a series of indazoles were designed, synthesized and evaluated as novel c-Met inhibitors. The results showed that the majority of the compounds exhibited significant inhibition on c-Met and compound 4d showed highest activity against c-Met with IC50 value of 0.17 μM in TR-FRET-based assay and IC50 value of 5.45 μM in cell-based assay as compared to other tested compounds. Molecular docking experiments verified the results and explained the molecular mechanism of pretty activities to c-Met.

  8. c-Met in chromophobe renal cell carcinoma.

    Science.gov (United States)

    Erlmeier, Franziska; Ivanyi, Philipp; Hartmann, Arndt; Autenrieth, Michael; Wiedemann, Max; Weichert, Wilko; Steffens, Sandra

    2017-02-01

    c-Met plays a role as a prognostic marker in clear cell renal cell carcinoma. In addition, recently the tyrosine kinase inhibitor cabozantinib targeting c-Met was approved for the treatment of advanced renal cell carcinoma (RCC). In contrast to clear cell RCC, little is known about c-Met expression patterns in rarer RCC subtypes. The aim of this study was to evaluate the prevalence, distribution and prognostic impact of c-Met expression on chromophobe (ch)RCC. Patients who underwent renal surgery due to chRCC were retrospectively evaluated. Tumor specimens were analyzed for c-Met expression by immunohistochemistry. Expression data were associated with clinicopathological parameters including patient survival. Eighty-one chRCC patients were eligible for analysis. Twenty-four (29.6%) patients showed a high c-Met expression (c-Met(high), staining intensity higher than median). Our results showed an association between c-Met(high) expression and the existence of lymph node metastasis (p = 0.007). No further significant clinicopathological associations with c-Met were identified, also regarding c-Met expression and overall survival. In conclusion, to our knowledge this is the first study evaluating the prognostic impact of c-Met in a considerably large cohort of chRCC. High c-Met expression is associated with the occurrence of lymph node metastasis. This indicates that c-Met might be implicated into metastatic progression in chRCC.

  9. Fibroblast growth factor 7 inhibits cholesterol 7{alpha}-hydroxylase gene expression in hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Zhichao [Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai (China); Yu, Xuemei [Department of Endocrinology, Fengxian Central Hospital, Shanghai (China); Wu, Weibin; Jia, Dongwei; Chen, Yinle; Ji, Lingling; Liu, Xijun; Peng, Xiaomin [Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai (China); Li, Yintao [Institute of Endocrinology and Diabetology, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai (China); Yang, Lili [Department of Endocrinology, Fengxian Central Hospital, Shanghai (China); Ruan, Yuanyuan; Gu, Jianxin [Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai (China); Ren, Shifang, E-mail: renshifang@fudan.edu.cn [Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai (China); Zhang, Songwen, E-mail: songwenzhang@fudan.edu.cn [Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai (China)

    2012-07-13

    Highlights: Black-Right-Pointing-Pointer FGF7 strongly and rapidly down-regulates the expression of CYP7A1 in hepatocytes. Black-Right-Pointing-Pointer FGF7 suppresses the expression of CYP7A1 via FGFR2 and downstream JNK activation. Black-Right-Pointing-Pointer Blocking FGF7 abrogates HSC-induced inhibition of CYP7A1 expression in hepatocytes. -- Abstract: Cholesterol 7{alpha}-hydroxylase (CYP7A1) is the initial and rate-limiting enzyme for bile acid synthesis. Transcription of the CYP7A1 gene is regulated by bile acids, nuclear receptors and cytokines. Fibroblast growth factor 7 (FGF7) secreted from activated hepatic stellate cells (HSC) during chronic liver fibrosis regulates hepatocyte survival and liver regeneration. In the carbon tetrachloride (CCl{sub 4})-induced fibrotic mouse liver, we demonstrated that the expression of CYP7A1 was largely decreased while the expression of FGF7 was significantly increased. We further demonstrated that FGF7 inhibited CYP7A1 gene expression in hepatocytes. Knockdown study by short interfering RNA, kinase inhibition and phosphorylation assays revealed that the suppression of CYP7A1 expression by FGF7 was mediated by FGFR2 and its downstream JNK signaling cascade. The FGF7 neutralizing antibody restored CYP7A1 expression in Hep3B cells treated with conditioned medium from HSC. In summary, the data suggest that FGF7 is a novel regulator of CYP7A1 expression in hepatocytes and may prevent hepatocytes from accumulating toxic bile acids during liver injury and fibrosis.

  10. Targeting HGF/c-MET induces cell cycle arrest, DNA damage, and apoptosis for primary effusion lymphoma.

    Science.gov (United States)

    Dai, Lu; Trillo-Tinoco, Jimena; Cao, Yueyu; Bonstaff, Karlie; Doyle, Lisa; Del Valle, Luis; Whitby, Denise; Parsons, Chris; Reiss, Krzysztof; Zabaleta, Jovanny; Qin, Zhiqiang

    2015-12-24

    Kaposi sarcoma-associated herpesvirus (KSHV) is a principal causative agent of primary effusion lymphoma (PEL) with a poor prognosis in immunocompromised patients. However, it still lacks effective treatment which urgently requires the identification of novel therapeutic targets for PEL. Here, we report that the hepatocyte growth factor (HGF)/c-MET pathway is highly activated by KSHV in vitro and in vivo. The selective c-MET inhibitor, PF-2341066, can induce PEL apoptosis through cell cycle arrest and DNA damage, and suppress tumor progression in a xenograft murine model. By using microarray analysis, we identify many novel genes that are potentially controlled by HGF/c-MET within PEL cells. One of the downstream candidates, ribonucleoside-diphosphate reductase subunit M2 (RRM2), also displays the promising therapeutic value for PEL treatment. Our findings provide the framework for development of HGF/c-MET-focused therapy and implementation of clinical trials for PEL patients.

  11. cMET in NSCLC: Can We Cut off the Head of the Hydra? From the Pathway to the Resistance

    Energy Technology Data Exchange (ETDEWEB)

    Van Der Steen, Nele [Center for Oncological Research Antwerp, University of Antwerp, Universiteitsplein 1, Wilrijk 2610 (Belgium); Pauwels, Patrick [Center for Oncological Research Antwerp, University of Antwerp, Universiteitsplein 1, Wilrijk 2610 (Belgium); Molecular Pathology Unit, Pathology Department, Antwerp University Hospital, Wilrijkstraat 10, Edegem 2650 (Belgium); Gil-Bazo, Ignacio [Department of Oncology, Clínica Universidad de Navarra, Pamplona 31008 (Spain); Castañon, Eduardo [Department of Oncology, Clínica Universidad de Navarra, Pamplona 31008 (Spain); Phase I-Early Clinical Trials Unit, Oncology Department, Antwerp University Hospital, Wilrijkstraat 10, Edegem 2650 (Belgium); Raez, Luis [Thoracic Oncology Program, Memorial Cancer Institute, Memorial Health Care System, Pembroke Pines, FL 33024 (United States); Cappuzzo, Federico [4Thoracic Oncology Program, Memorial Cancer Institute, Memorial Health Care System, Pembroke Pines, FL 33024 (United States); Rolfo, Christian, E-mail: Christian.Rolfo@uza.be [Center for Oncological Research Antwerp, University of Antwerp, Universiteitsplein 1, Wilrijk 2610 (Belgium); Phase I-Early Clinical Trials Unit, Oncology Department, Antwerp University Hospital, Wilrijkstraat 10, Edegem 2650 (Belgium)

    2015-03-25

    In the last decade, the tyrosine kinase receptor cMET, together with its ligand hepatocyte growth factor (HGF), has become a target in non-small cell lung cancer (NSCLC). Signalization via cMET stimulates several oncological processes amongst which are cell motility, invasion and metastasis. It also confers resistance against several currently used targeted therapies, e.g., epidermal growth factor receptor (EGFR) inhibitors. In this review, we will discuss the basic structure of cMET and the most important signaling pathways. We will also look into aberrations in the signaling and the effects thereof in cancer growth, with the focus on NSCLC. Finally, we will discuss the role of cMET as resistance mechanism.

  12. Leflunomide attenuates hepatocyte injury by inhibiting Kupffer cells

    Institute of Scientific and Technical Information of China (English)

    Hong-Wei Yao; Jun Li; Ji-Qiang Chen; Shu-Yun Xu

    2004-01-01

    AIM: To investigate the importance of direct contact between Kupffer cells (KCs) and hepatocytes (HCs) during hepatic inflammatory responses, and the effect of leflunomide′s active metabolite, A771726, on cytokines in KCs, HCs and KC cocultures (DC cocultures).METHODS: KCs and HCs in liver were isolated by digestion with pronase and collagenase. Lipopolysaccharide (LPS)-induced inflammatory response in monocultures of rat HCs and KCs was compared with that in DC cocultures. Tumor necrosis factor-α (TNF-α) and interleukin-1 (IL-1)concentrations in different culture supernatants were measured with ELISA. TNF-α mRNA in KCs of inflammatory liver injury was analyzed with reverse transcriptase polymerase chain reaction (RT-PCR).RESULTS: DC cocultures strongly exhibited the production of TNF-α and IL-1 compared with other cultures, and these cytokines were mainly produced by KCs, especially by activated KCs. Time course studies revealed an increased production of TNF-α preceding the IL-1 production,suggesting that increased TNF-α levels could be involved in the increase of IL-1 production. Leflunomide′s active metabolite, A771726, had significantly inhibitory effect on TNF-αand IL-1 at protein and transcription levels, and the reduced production of IL-1 by A771726 was associated with the inhibitory action of A771726 on TNF-α.

  13. Development of antibody-based c-Met inhibitors for targeted cancer therapy

    Directory of Open Access Journals (Sweden)

    Lee D

    2015-02-01

    Full Text Available Dongheon Lee, Eun-Sil Sung, Jin-Hyung Ahn, Sungwon An, Jiwon Huh, Weon-Kyoo You Hanwha Chemical R&D Center, Biologics Business Unit, Daejeon, Republic of Korea Abstract: Signaling pathways mediated by receptor tyrosine kinases (RTKs and their ligands play important roles in the development and progression of human cancers, which makes RTK-mediated signaling pathways promising therapeutic targets in the treatment of cancer. Compared with small-molecule compounds, antibody-based therapeutics can more specifically recognize and bind to ligands and RTKs. Several antibody inhibitors of RTK-mediated signaling pathways, such as human epidermal growth factor receptor 2, vascular endothelial growth factor, epidermal growth factor receptor or vascular endothelial growth factor receptor 2, have been developed and are widely used to treat cancer patients. However, since the therapeutic options are still limited in terms of therapeutic efficacy and types of cancers that can be treated, efforts are being made to identify and evaluate novel RTK-mediated signaling pathways as targets for more efficacious cancer treatment. The hepatocyte growth factor/c-Met signaling pathway has come into the spotlight as a promising target for development of potent cancer therapeutic agents. Multiple antibody-based therapeutics targeting hepatocyte growth factor or c-Met are currently in preclinical or clinical development. This review focuses on the development of inhibitors of the hepatocyte growth factor/c-Met signaling pathway for cancer treatment, including critical issues in clinical development and future perspectives for antibody-based therapeutics. Keywords: hepatocyte growth factor, ligands, receptor tyrosine kinase, signaling pathway, therapeutic agent

  14. c-Met inhibitor SU11274 enhances the response of the prostate cancer cell line DU145 to ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Hongliang; Li, Xiaoying; Sun, Shaoqian [Department of Radiation Oncology, Peking University First Hospital, Peking University, Beijing (China); Gao, Xianshu, E-mail: xsgao777@hotmail.com [Department of Radiation Oncology, Peking University First Hospital, Peking University, Beijing (China); Zhou, Demin, E-mail: deminzhou@bjmu.edu.cn [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing (China)

    2012-10-26

    Highlights: Black-Right-Pointing-Pointer c-Met inhibition could significantly enhance the radiosensitivity of DU145 cells. Black-Right-Pointing-Pointer The mechanisms of the radiosensitization effect of c-Met inhibition on DU145 cells were also presented in this paper. Black-Right-Pointing-Pointer This is the first study demonstrating the effectiveness of c-Met inhibition on treating HRPC cells with radiotherapy. -- Abstract: Hormone-refractory prostate cancer shows substantial resistance to most conventional therapies including radiotherapy, constitutes a key impediment to curing patients with the disease. c-Met overexpression plays a key role in prostate cancer tumorigenesis and disease progression. Here, we demonstrate that c-Met inhibition by SU11274 could significantly suppress cell survival and proliferation as well as enhance the radiosensitivity of DU145 cells. The underlying mechanisms of the effects of SU11274 on DU145 cells may include the inhibition of c-Met signaling, depolarization of the mitochondrial membrane potential, impairment of DNA repair function, abrogation of cell cycle arrest, and enhancement of cell death. Our study is the first to show the effectiveness of combining c-Met inhibition with ionizing radiation to cure hormone-refractory prostate cancer.

  15. Farnesoid X Receptor Inhibits the Transcriptional Activity of Carbohydrate Response Element Binding Protein in Human Hepatocytes

    Science.gov (United States)

    Caron, Sandrine; Huaman Samanez, Carolina; Dehondt, Hélène; Ploton, Maheul; Briand, Olivier; Lien, Fleur; Dorchies, Emilie; Dumont, Julie; Postic, Catherine; Cariou, Bertrand; Lefebvre, Philippe

    2013-01-01

    The glucose-activated transcription factor carbohydrate response element binding protein (ChREBP) induces the expression of hepatic glycolytic and lipogenic genes. The farnesoid X receptor (FXR) is a nuclear bile acid receptor controlling bile acid, lipid, and glucose homeostasis. FXR negatively regulates hepatic glycolysis and lipogenesis in mouse liver. The aim of this study was to determine whether FXR regulates the transcriptional activity of ChREBP in human hepatocytes and to unravel the underlying molecular mechanisms. Agonist-activated FXR inhibits glucose-induced transcription of several glycolytic genes, including the liver-type pyruvate kinase gene (L-PK), in the immortalized human hepatocyte (IHH) and HepaRG cell lines. This inhibition requires the L4L3 region of the L-PK promoter, known to bind the transcription factors ChREBP and hepatocyte nuclear factor 4α (HNF4α). FXR interacts directly with ChREBP and HNF4α proteins. Analysis of the protein complex bound to the L4L3 region reveals the presence of ChREBP, HNF4α, FXR, and the transcriptional coactivators p300 and CBP at high glucose concentrations. FXR activation does not affect either FXR or HNF4α binding to the L4L3 region but does result in the concomitant release of ChREBP, p300, and CBP and in the recruitment of the transcriptional corepressor SMRT. Thus, FXR transrepresses the expression of genes involved in glycolysis in human hepatocytes. PMID:23530060

  16. Activation of c-MET induces a stem-like phenotype in human prostate cancer.

    Directory of Open Access Journals (Sweden)

    Geert J L H van Leenders

    Full Text Available Prostate cancer consists of secretory cells and a population of immature cells. The function of immature cells and their mutual relation with secretory cells are still poorly understood. Immature cells either have a hierarchical relation to secretory cells (stem cell model or represent an inducible population emerging upon appropriate stimulation of differentiated cells. Hepatocyte Growth Factor (HGF receptor c-MET is specifically expressed in immature prostate cells. Our objective is to determine the role of immature cells in prostate cancer by analysis of the HGF/c-MET pathway.Gene-expression profiling of DU145 prostate cancer cells stimulated with HGF revealed induction of a molecular signature associated with stem cells, characterized by up-regulation of CD49b, CD49f, CD44 and SOX9, and down-regulation of CD24 ('stem-like signature'. We confirmed the acquisition of a stem-like phenotype by quantitative PCR, FACS analysis and Western blotting. Further, HGF led to activation of the stem cell related Notch pathway by up-regulation of its ligands Jagged-1 and Delta-like 4. Small molecules SU11274 and PHA665752 targeting c-MET activity were both able to block the molecular and biologic effects of HGF. Knock-down of c-MET by shRNA infection resulted in significant reduction and delay of orthotopic tumour-formation in male NMRI mice. Immunohistochemical analysis in prostatectomies revealed significant enrichment of c-MET positive cells at the invasive front, and demonstrated co-expression of c-MET with stem-like markers CD49b and CD49f.In conclusion, activation of c-MET in prostate cancer cells induced a stem-like phenotype, indicating a dynamic relation between differentiated and stem-like cells in this malignancy. Its mediation of efficient tumour-formation in vivo and predominant receptor expression at the invasive front implicate that c-MET regulates tumour infiltration in surrounding tissues putatively by acquisition of a stem-like phenotype.

  17. 6-Phosphogluconate dehydrogenase regulates tumor cell migration in vitro by regulating receptor tyrosine kinase c-Met

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Barden, E-mail: cchan@bidmc.harvard.edu [Division of Interdisciplinary Medicine and Biotechnology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215 (United States); VanderLaan, Paul A. [Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215 (United States); Sukhatme, Vikas P. [Division of Interdisciplinary Medicine and Biotechnology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215 (United States)

    2013-09-20

    Highlights: •Expression of 6PGD positively correlates with advancing stage of lung carcinoma. •Knockdown of 6PGD by shRNA potently inhibits c-Met tyrosine phosphorylation. •Exogenous HGF fails to restore c-Met phosphorylation in cells with 6PGD knocked down. •6PGD knockdown results in inhibition of cell migration in vitro. •Constitutively active TPR-cMet significantly restores migration of cells without 6PGD. -- Abstract: 6-Phosphogluconate dehydrogenase (6PGD) is the third enzyme in the oxidative pentose phosphate pathway (PPP). Recently, we reported that knockdown of 6PGD inhibited lung tumor growth in vitro and in a xenograft model in mice. In this study, we continued to examine the functional role of 6PGD in cancer. We show that 6PGD expression positively correlates with advancing stage of lung carcinoma. In search of functional signals related to 6PGD, we discovered that knockdown of 6PGD significantly inhibited phosphorylation of c-Met at tyrosine residues known to be critical for activity. This downregulation of c-Met phosphorylation correlated with inhibition of cell migration in vitro. Overexpression of a constitutively active c-Met specifically rescued the migration but not proliferation phenotype of 6PGD knockdown. Therefore, 6PGD appears to be required for efficient c-Met signaling and migration of tumor cells in vitro.

  18. Inhibition of glycogen synthesis in rat hepatocytes by medium Zn/sup 2 +/

    Energy Technology Data Exchange (ETDEWEB)

    Rognstad, R.

    1984-07-31

    In hepatocytes from fasted rats, Zn/sup 2 +/ in the range from 0 to 500..mu..M has relatively minor effects on gluconeogenesis from most substrates, or on ureagenesis from NH/sub 3/. In hepatocytes from fed rats, Zn/sup 2 +/ does not affect glycogenolysis. In hepatocytes from fasted rats, in which glycogen is being actively synthesized using the substrate combination of glycose, lactate and glutamine (all 10mM), Zn/sup 2 +/ markedly inhibits glucogen synthesis, with total inhibition at 500..mu..M, and a half maximal effect in the range from 50 to 100..mu..M. Dipicolinate (pyridine 2,6-dicarboxylate), a zinc chelator, is about as effective as L-glutamine in activating glycogen synthesis with the substrate combination of dihydroxyacetone, lactate and glucose (all 10mM). This suggests the possible hypothesis that endogenous Zn/sup 2 +/ might control the rate of glycogen synthesis in vivo. However, alternate explanations such as metabolite accumulation are also possible, since dipicolinate causes inhibition of gluconeogenesis from L-lactate. 28 references, 3 tables.

  19. SF/HGF-c-Met autocrine and paracrine promote metastasis of hepatocellular carcinoma

    Institute of Scientific and Technical Information of China (English)

    Qian Xie; Kang-Da Liu; Mei-Yu Hu; Kang Zhou

    2001-01-01

    AIM: To explore the role of SF/HGF-Met autocrine and parscrine in metastasis of hepatocellular carcinoma (HCC). METHODS: SF/HGF and c-met transcription and protein expression in HCC were examined by RT-PCR and Western Blot in 4 HCC cell lines, including HepG2, Hep3B,SMMC7721 and MHCC-1, the last cell line had a higher potential of metastasis. Sf/hgf cDNA was transfected by the method of Lipofectin into SMMC7721. SF/HGF and c-met antibody were used to stimulate and block SF/HGF-c-met signal transduction. Cell morphology, mobility, and proliferation were respectively compared by microscopic observation, wound healing assay and cell growth curve. RESULTS: HCC malignancy appeared to be relative to its met-SF/HGF expression. In MHCC-1, c-met expression was much stronger than that in other cell lines with lower potential of metastasis and only SF/HGF autocrine existed in MHCC-1. After sf/hgf cDNA transfection or conditioned medium of MHCC-1 stimulation, SMMC7721 changed into elongated morphology, and the abilities of proliferation ( P < 0.05) and mobility increased. Such bio-activity could he blocked by c-met antibody ( P< 0.05). CONCLUSION: The system of SF/HGF-c-met autocrine and paracrine played an important role in development and metastasis potential of HCC. Inhibition of SF/HGF-c-met signal transduction system may reduce the growth and metastasis of HCC.

  20. Absence of tpr-met and expression of c-met in human gastric mucosa and carcinoma.

    Science.gov (United States)

    Heideman, D A; Snijders, P J; Bloemena, E; Meijer, C J; Offerhaus, G J; Meuwissen, S G; Gerritsen, W R; Craanen, M E

    2001-08-01

    The c-met proto-oncogene, encoding the hepatocyte growth factor receptor, can be activated by various mechanisms. These include, among others, gene amplification with concomitant overexpression and the tpr-met oncogenic rearrangement. In the case of gastric cancer, contradictory results on the presence of the tpr-met oncogenic rearrangement have been published. The current study aimed therefore to assess the prevalence of tpr-met expression in Caucasian gastric adenocarcinomas, to evaluate the importance of this oncogene in their carcinogenesis. In addition, the level of c-met expression was determined, to evaluate the role of this alternative mode of activation of the proto-oncogene. A series of Caucasian gastric adenocarcinomas (n=43) and normal gastric mucosal samples (n=14) was analysed for tpr-met and c-met expression. Expression of tpr-met mRNA in the samples was performed by two reverse transcriptase polymerase chain reaction (RT-PCR) assays, with excellent correlation. The specificity of both methods was confirmed by direct sequencing of the PCR products of the MNNG-HOS cell line, which is known to contain the rearrangement. The level of c-met expression was assessed using semi-quantitative RT-PCR assays and immunohistochemistry (IHC). None of the normal gastric mucosal or gastric adenocarcinoma samples expressed tpr-met mRNA, as determined by both RT-PCR assays. Seventy per cent of the adenocarcinomas showed overexpression of c-met, according to elevated c-met mRNA levels, compared with the expression level of normal gastric mucosa. A significant correlation was found between the level of c-met mRNA and protein expression. In conclusion, these results strongly suggest that tpr-met activation does not play a role in Caucasian gastric carcinogenesis, while overexpression of the c-met gene occurs in the majority of Caucasian gastric adenocarcinomas.

  1. Sulindac and its metabolites inhibit multiple transport proteins in rat and human hepatocytes.

    Science.gov (United States)

    Lee, Jin Kyung; Paine, Mary F; Brouwer, Kim L R

    2010-08-01

    Sulindac is a commonly used nonsteroidal anti-inflammatory drug. This study tested the hypothesis that sulindac-mediated drug-drug interactions and/or hepatotoxicity may be caused, in part, by inhibition of proteins responsible for the hepatic transport of drugs and/or bile acids by sulindac and/or sulindac metabolites [sulindac sulfone (S-sulfone) and sulindac sulfide (S-sulfide)]. The uptake and excretion of model substrates, [(3)H]taurocholate (TC), [(3)H]estradiol 17-beta-glucuronide (E217G), and nitrofurantoin (NF), were investigated in rat and human suspended and sandwich-cultured hepatocytes (SCH). In suspended rat hepatocytes, S-sulfone and S-sulfide inhibited Na(+)-dependent TC initial uptake (IC(50) of 24.9 +/- 6.4 and 12.5 +/- 1.8 microM, respectively) and Na(+)-independent E217G initial uptake (IC(50) of 12.1 +/- 1.6 and 6.3 +/- 0.3 microM, respectively). In rat SCH, sulindac metabolites (100 microM) decreased the in vitro biliary clearance (Cl(biliary)) of TC, E217G, and NF by 38 to 83%, 81 to 97%, and 33 to 57%, respectively; S-sulfone and S-sulfide also decreased the TC and NF biliary excretion index by 39 to 55%. In suspended human hepatocytes, S-sulfone and S-sulfide inhibited Na(+)-dependent TC initial uptake (IC(50) of 42.2 and 3.1 microM, respectively); S-sulfide also inhibited the TC Cl(biliary) in human SCH. Sulindac/metabolites markedly inhibited hepatic uptake and biliary excretion of E217G by 51 to 100% in human SCH. In conclusion, sulindac and metabolites are potent inhibitors of the uptake and biliary clearance of bile acids in rat and human hepatocytes and also inhibit substrates of rat breast cancer resistance protein, rat and human organic anion-transporting polypeptides, and human multidrug resistance-associated protein 2. Inhibition of multiple hepatic transport proteins by sulindac/metabolites may play an important role in clinically significant sulindac-mediated drug-drug interactions and/or liver injury.

  2. Potential inhibition of cytochrome P450 3A4 by propofol in human primary hepatocytes

    Institute of Scientific and Technical Information of China (English)

    Li-Qun Yang; Wei-Feng Yu; Yun-Fei Cao; Bin Gong; Qing Chang; Guang-Shun Yang

    2003-01-01

    AIM: Hepatic cytochrome P450 isoenzymes constitute a superfamily of hemoproteins that play a major role in the metabolism of endogenous compounds and in the detoxification of xenobiotic molecules. P450 3A4 is one of the most important forms in human being, and mediates the metabolism of around 70% of therapeutic drugs and endogenous compounds. Propofol, a widely used intravenous anesthetic drug, is known to inhibit cytochrome P450activities in isolated rat hepatocytes. The goal of this study was to evaluate the potential efficacy of propofol on P4503A4 in a dose-dependent manner to understand its drugdrug interaction.METHODS: Hepatocytes were isolated from liver specimens from hepatic angioma patients undergone hepatic surgery.Primary incubated hepatocytes were treated with 0, 0.01,0.05, 0.1, 0.5, and 1.0 mM propofol for 24 hours. P450 3A4activity was measured with Nash′s colorimetry. The protein expression was assessed by Western blot analysis.RESULTS: A dose-dependent inhibitory effect of propofol was observed in cytochrome P450 3A4 activity. A minimal dosage of propofol (0.01 mM) induced a significant inhibition of P450 3A4 activity, although its regular dosages (0.01-0.1mM) showed no inhibitory effect on the cellular protein expression of P450 3A4.CONCLUSION: Propofol may be a potential CYP3A4 inhibitor as this anesthetic can inhibit isoenzyme activity significantly and reduce the metabolic rate of CYP3A4 substrates. This inhibition occurs at post-expression level, and concentration of propofol used clinically does not affect CYP3A4 protein expression. propofol may thus induce drug interaction of cytochrome P450 3A4 activity at the dosage used clinically.

  3. cAMP prevents TNF-induced apoptosis through inhibiting DISC complex formation in rat hepatocytes.

    Science.gov (United States)

    Bhattacharjee, Rajesh; Xiang, Wenpei; Wang, Yinna; Zhang, Xiaoying; Billiar, Timothy R

    2012-06-22

    Tumor necrosis factor α (TNF) is a pleiotropic proinflammatory cytokine that plays a role in immunity and the control of cell proliferation, cell differentiation, and apoptosis. The pleiotropic nature of TNF is due to the formation of different signaling complexes upon the binding of TNF to its receptor, TNF receptor type 1 (TNFR1). TNF induces apoptosis in various mammalian cells when the cells are co-treated with a transcription inhibitor like actinomycin D (ActD). When TNFR1 is activated, it recruits an adaptor protein, TNF receptor-associated protein with death domain (TRADD), through its cytoplasmic death effector domain (DED). TRADD, in turn, recruits other signaling proteins, including TNF receptor-associated protein 2 (TRAF2) and receptor-associated protein kinase (RIPK) 1, to form a complex. Subsequently, this complex combines with FADD and procaspase-8, converts into a death-inducing signaling complex (DISC) to induce apoptosis. Cyclic AMP (cAMP) is a second messenger that regulates various cellular processes such as cell proliferation, gene expression, and apoptosis. cAMP analogues are reported to act as anti-apoptotic agents in various cell types, including hepatocytes. We found that a cAMP analogue, dibutyryl cAMP (db-cAMP), inhibits TNF+ActD-induced apoptosis in rat hepatocytes. The protein kinase A (PKA) inhibitor KT-5720 reverses this inhibitory effect of cAMP on apoptosis. Cytoprotection by cAMP involves down-regulation of various apoptotic signal regulators like TRADD and FADD and inhibition of caspase-8 and caspase-3 cleavage. We also found that cAMP exerts its affect at the proximal level of TNF signaling by inhibiting the formation of the DISC complex upon the binding of TNF to TNFR1. In conclusion, our study shows that cAMP prevents TNF+ActD-induced apoptosis in rat hepatocytes by inhibiting DISC complex formation.

  4. Evaluation of c-Met, HGF, and HER-2 expressions in gastric carcinoma and their association with other clinicopathological factors

    Directory of Open Access Journals (Sweden)

    Yıldız Y

    2016-09-01

    Full Text Available Yetkin Yıldız,1 Cenk Sokmensuer,2 Suayib Yalcin1 1Department of Medical Oncology, 2Department of Pathology, Hacettepe University, Ankara, Turkey Background: Met and HER-2 are proto-oncogenes encoding receptor tyrosine kinase c-Met and HER-2, respectively. Hepatocyte growth factor (HGF is a ligand of c-Met. The frequency of c-Met, HGF, and HER-2 expressions in gastric cancer and their association with other clinicopathological factors have not been fully understood. Patients and methods: Patients with stage 1–4 disease were analyzed. Expressions of c-Met, HGF, and HER-2 were examined using immunohistochemistry. Results: A total of 143 patients, 97 males and 46 females, were included. C-Met scores were 3(+ in 31.5%, 2(+ in 27.3%, and 1(+ in 10.5% of the patients. There was no statistically significant difference in age, sex, tumor location, differentiation, Lauren classification, TNM staging, presence of distant metastasis, depth of tumor invasion (T, lymphovascular invasion, and survival between c-Met subgroups. Overall HGF positivity was 20.6%. HER-2 scores were 3(+ in 9.1%, 2(+ in 9.8%, and 1(+ in 16.1% of the patients. HER-2 overexpression was associated with better differentiation, intestinal subtype, and advanced stage. C-Met overexpressions were 84.6% in the HER-2-overexpression-positive group and 56.2% in the HER-2-overexpression-negative group. There were no statistically significant differences in survival between the high c-Met-expression-positive and -negative stage 3 and stage 4 patients and between the HGF-positive and -negative groups. The mean survival was 11.6±6.3 months in the HER-2-overexpression-positive stage 4 group and 11.9±6.8 months in the HER-2-overexpression-negative stage 4 group. There were no statistically significant differences in survival between the two groups. Conclusion: c-Met was not associated with any prognostic factors in gastric cancer. HER-2 was associated with better differentiation, intestinal

  5. cAMP prevents TNF-induced apoptosis through inhibiting DISC complex formation in rat hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharjee, Rajesh [Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA 15213 (United States); Xiang, Wenpei [Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA 15213 (United States); Family Planning Research Institute, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, People' s Republic of China (China); Wang, Yinna [Vascular Medicine Institute, University of Pittsburgh School of Medicine, 10051-5A BST 3, 3501 Fifth Avenue, Pittsburgh, PA 15261 (United States); Zhang, Xiaoying [Department of Medicine/Endocrinology Division, University of Pittsburgh Medical Center, 200 Lothrop St., Pittsburgh, PA 15213 (United States); Billiar, Timothy R., E-mail: billiartr@upmc.edu [Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA 15213 (United States)

    2012-06-22

    Highlights: Black-Right-Pointing-Pointer cAMP blocks cell death induced by TNF and actinomycin D in cultured hepatocytes. Black-Right-Pointing-Pointer cAMP blocks NF-{kappa}B activation induced by TNF and actinomycin D. Black-Right-Pointing-Pointer cAMP blocks DISC formation following TNF and actinomycin D exposure. Black-Right-Pointing-Pointer cAMP blocks TNF signaling at a proximal step. -- Abstract: Tumor necrosis factor {alpha} (TNF) is a pleiotropic proinflammatory cytokine that plays a role in immunity and the control of cell proliferation, cell differentiation, and apoptosis. The pleiotropic nature of TNF is due to the formation of different signaling complexes upon the binding of TNF to its receptor, TNF receptor type 1 (TNFR1). TNF induces apoptosis in various mammalian cells when the cells are co-treated with a transcription inhibitor like actinomycin D (ActD). When TNFR1 is activated, it recruits an adaptor protein, TNF receptor-associated protein with death domain (TRADD), through its cytoplasmic death effector domain (DED). TRADD, in turn, recruits other signaling proteins, including TNF receptor-associated protein 2 (TRAF2) and receptor-associated protein kinase (RIPK) 1, to form a complex. Subsequently, this complex combines with FADD and procaspase-8, converts into a death-inducing signaling complex (DISC) to induce apoptosis. Cyclic AMP (cAMP) is a second messenger that regulates various cellular processes such as cell proliferation, gene expression, and apoptosis. cAMP analogues are reported to act as anti-apoptotic agents in various cell types, including hepatocytes. We found that a cAMP analogue, dibutyryl cAMP (db-cAMP), inhibits TNF + ActD-induced apoptosis in rat hepatocytes. The protein kinase A (PKA) inhibitor KT-5720 reverses this inhibitory effect of cAMP on apoptosis. Cytoprotection by cAMP involves down-regulation of various apoptotic signal regulators like TRADD and FADD and inhibition of caspase-8 and caspase-3 cleavage. We also found

  6. Fc-mediated activity of EGFR x c-Met bispecific antibody JNJ-61186372 enhanced killing of lung cancer cells.

    Science.gov (United States)

    Grugan, Katharine D; Dorn, Keri; Jarantow, Stephen W; Bushey, Barbara S; Pardinas, Jose R; Laquerre, Sylvie; Moores, Sheri L; Chiu, Mark L

    2017-01-01

    Epidermal growth factor receptor (EGFR) mutant non-small cell lung cancers acquire resistance to EGFR tyrosine kinase inhibitors through multiple mechanisms including c-Met receptor pathway activation. We generated a bispecific antibody targeting EGFR and c-Met (JNJ-61186372) demonstrating anti-tumor activity in wild-type and mutant EGFR settings with c-Met pathway activation. JNJ-61186372 was engineered with low fucosylation (<10 %), resulting in enhanced antibody-dependent cell-mediated cytotoxicity and FcγRIIIa binding. In vitro and in vivo studies with the single-arm EGFR or c-Met versions of JNJ-61186372 identified that the Fc-activity of JNJ-61186372 is mediated by binding of the anti-EGFR arm and required for inhibition of EGFR-driven tumor cells. In a tumor model driven by both EGFR and c-Met, treatment with Fc-silent JNJ-61186372 or with c-Met single-arm antibody reduced tumor growth inhibition compared to treatment with JNJ-61186372, suggesting that the Fc function of JNJ-61186372 is essential for maximal tumor inhibition. Moreover in this same model, downregulation of both EGFR and c-Met receptors was observed upon treatment with Fc-competent JNJ-61186372, suggesting that the Fc interactions are necessary for down-modulation of the receptors in vivo and for efficacy. These Fc-mediated activities, in combination with inhibition of both the EGFR and c-Met signaling pathways, highlight the multiple mechanisms by which JNJ-61186372 combats therapeutic resistance in EGFR mutant patients.

  7. Low c-Met expression levels are prognostic for and predict the benefits of temozolomide chemotherapy in malignant gliomas

    Science.gov (United States)

    Li, Ming-Yang; Yang, Pei; Liu, Yan-Wei; Zhang, Chuan-Bao; Wang, Kuan-Yu; Wang, Yin-Yan; Yao, Kun; Zhang, Wei; Qiu, Xiao-Guang; Li, Wen-Bin; Peng, Xiao-Xia; Wang, Yong-Zhi; Jiang, Tao

    2016-01-01

    Aberrant c-Met has been implicated in the development of many cancers. The objective of this study was to identify an unfavorable prognostic marker that might guide decisions regarding clinical treatment strategies for high-grade gliomas. C-Met expression was measured using immunohistochemistry in 783 gliomas, and we further analyzed c-Met mRNA levels using the Agilent Whole Genome mRNA Microarray in 286 frozen samples. In vitro, we performed cell migration and invasion assays. Cell sensitivity to temozolomide (TMZ) chemotherapy was determined using MTT assays. Both mRNA and protein levels of c-Met were significantly associated with tumor grade progression and inversely correlated with overall and progression-free survival in high-grade gliomas (all P < 0.0001). These findings were nearly consistent at the mRNA level across 3 independent cohorts. Multivariable analysis indicated that c-Met was an independent prognostic marker after adjusting for age, preoperative Karnofsky Performance Status (KPS) score, the extent of resection, radiotherapy, TMZ chemotherapy, and O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status. Further analysis in vitro revealed that downregulating the expression of c-Met dramatically inhibited cell migration and invasion capacities, enhanced sensitivity to TMZ chemotherapy in H4 and U87 glioma cells. Our results suggest that c-Met may serve as a potential predictive maker for clinical decision making. PMID:26879272

  8. Evaluation of c-Met, HGF, and HER-2 expressions in gastric carcinoma and their association with other clinicopathological factors

    Science.gov (United States)

    Yıldız, Yetkin; Sokmensuer, Cenk; Yalcin, Suayib

    2016-01-01

    Background Met and HER-2 are proto-oncogenes encoding receptor tyrosine kinase c-Met and HER-2, respectively. Hepatocyte growth factor (HGF) is a ligand of c-Met. The frequency of c-Met, HGF, and HER-2 expressions in gastric cancer and their association with other clinicopathological factors have not been fully understood. Patients and methods Patients with stage 1–4 disease were analyzed. Expressions of c-Met, HGF, and HER-2 were examined using immunohistochemistry. Results A total of 143 patients, 97 males and 46 females, were included. C-Met scores were 3(+) in 31.5%, 2(+) in 27.3%, and 1(+) in 10.5% of the patients. There was no statistically significant difference in age, sex, tumor location, differentiation, Lauren classification, TNM staging, presence of distant metastasis, depth of tumor invasion (T), lymphovascular invasion, and survival between c-Met subgroups. Overall HGF positivity was 20.6%. HER-2 scores were 3(+) in 9.1%, 2(+) in 9.8%, and 1(+) in 16.1% of the patients. HER-2 overexpression was associated with better differentiation, intestinal subtype, and advanced stage. C-Met overexpressions were 84.6% in the HER-2-overexpression-positive group and 56.2% in the HER-2-overexpression-negative group. There were no statistically significant differences in survival between the high c-Met-expression-positive and -negative stage 3 and stage 4 patients and between the HGF-positive and -negative groups. The mean survival was 11.6±6.3 months in the HER-2-overexpression-positive stage 4 group and 11.9±6.8 months in the HER-2-overexpression-negative stage 4 group. There were no statistically significant differences in survival between the two groups. Conclusion c-Met was not associated with any prognostic factors in gastric cancer. HER-2 was associated with better differentiation, intestinal subtype, advanced stage, and c-Met overexpression. PMID:27703380

  9. The c-Met receptor tyrosine kinase inhibitor MP470 radiosensitizes glioblastoma cells

    Directory of Open Access Journals (Sweden)

    Bearss David

    2009-12-01

    Full Text Available Abstract Purpose Glioblastoma multiforme (GBM is resistant to current cytotoxic therapies, in part because of enhanced DNA repair. Activation of the receptor tyrosine kinase c-Met has been shown to protect cancer cells from DNA damage. We hypothesized that inhibiting c-Met would decrease this protection and thus sensitize resistant tumor cells to the effects of radiation therapy. Materials and methods Eight human GBM cell lines were screened for radiosensitivity to the small-molecule c-Met inhibitor MP470 with colony-count assays. Double-strand (ds DNA breaks was quantified by using antibodies to gamma H2AX. Western blotting demonstrate expression of RAD51, glycogen synthase kinase (GSK-3β, and other proteins. A murine xenograft tumor flank model was used for in vivo radiosensitization studies. Results MP470 reduced c-Met phosphorylation and enhanced radiation-induced cell kill by 0.4 logs in SF767 cells. Cells pretreated with MP470 had more ds DNA damage than cells treated with radiation alone. Mechanistically, MP470 was shown to inhibit dsDNA break repair and increase apoptosis. MP470 influences various survival and DNA repair related proteins such as pAKT, RAD51 and GSK3β. In vivo, the addition of MP470 to radiation resulted in a tumor-growth-delay enhancement ratio of 2.9 over radiation alone and extended survival time. Conclusions GBM is a disease site where radiation is often used to address both macroscopic and microscopic disease. Despite attempts at dose escalation outcomes remain poor. MP470, a potent small-molecule tyrosine kinase inhibitor of c-Met, radiosensitized several GBM cell lines both in vitro and in vivo, and may help to improve outcomes for patients with GBM.

  10. The indole alkaloid meleagrin, from the olive tree endophytic fungus Penicillium chrysogenum, as a novel lead for the control of c-Met-dependent breast cancer proliferation, migration and invasion.

    Science.gov (United States)

    Mady, Mohamed S; Mohyeldin, Mohamed M; Ebrahim, Hassan Y; Elsayed, Heba E; Houssen, Wael E; Haggag, Eman G; Soliman, Randa F; El Sayed, Khalid A

    2016-01-15

    Fungi of the genus Penicillium produce unique and chemically diverse biologically active secondary metabolites, including indole alkaloids. The role of dysregulated hepatocyte growth factor (HGF) and its receptor, c-Met, in the development and progression of breast carcinoma is documented. The goal of this work is to explore the chemistry and bioactivity of the secondary metabolites of the endophytic Penicillium chrysogenum cultured from the leaf of the olive tree Olea europea, collected in its natural habitat in Egypt. This fungal extract showed good inhibitory activities against the proliferation and migration of several human breast cancer lines. The CH2Cl2 extract of P. chrysogenum mycelia was subjected to bioguided chromatographic separation to afford three known indole alkaloids; meleagrin (1), roquefortine C (2) and DHTD (3). Meleagrin inhibited the growth of the human breast cancer cell lines MDA-MB-231, MDA-468, BT-474, SK BR-3, MCF7 and MCF7-dox, while similar treatment doses were found to have no effect on the growth and viability of the non-tumorigenic human mammary epithelial cells MCF10A. Meleagrin also showed excellent ATP competitive c-Met inhibitory activity in Z-Lyte assay, which was further confirmed via molecular docking studies and Western blot analysis. In addition, meleagrin treatment caused a dose-dependent inhibition of HGF-induced cell migration, and invasion of breast cancer cell lines. Meleagrin treatment potently suppressed the invasive triple negative breast tumor cell growth in an orthotopic athymic nude mice model, promoting this unique natural product from hit to a lead rank. The indole alkaloid meleagrin is a novel lead c-Met inhibitory entity useful for the control of c-Met-dependent metastatic and invasive breast malignancies.

  11. HGF/c-MET Pathway in AIDS-Related Lymphoma

    Science.gov (United States)

    2016-09-01

    Russell DL. The metalloproteinase ADAMTS1: a comprehensive review of its role in tumorigenic and metastatic pathways . Int J Cancer . 2013; 133...protein kinase and p38 pathways acting on hypoxia-inducible factor 1alpha. Cancer Res. 2000; 60:4873–4880. 45. Dai L, Trillo-Tinoco J, Bai L, Kang B...Louisiana Cancer Research Center, New Orleans, LA Key Points • The HGF/c-MET pathway has a complex network to control KSHV1 PEL cell survival. • The c-MET

  12. INHIBITION OF BILE ACID ACCUMULATION DECREASED THE EXCESSIVE HEPATOCYTE APOPTOSIS AND IMPROVED THE LIVER SECRETION FUNCTIONS ON OBSTRUCTIVE JAUNDICE PATIENTS

    Directory of Open Access Journals (Sweden)

    Akmal Taher

    2011-06-01

    Full Text Available Excessive hepatocyte apoptosis induced by bile acid accumulation occurred in severe obstructive jaundice, and impair the liver secretion function. The objective of this study is to determine whether the inhibition of bile acid accumulation through bile duct decompression affect the excessive hepatocyte apoptosis and caused improvement the liver secretion functions on human model. In this study we use a before and after study on severe obstructive jaundice patients due to extra hepatic bile duct tumor was decompressed. Bile duct decompression was performed as a model of the role of inhibition of bile acid accumulation inhibition bile acid accumulation and excessive hepatocyte apoptosis. Bile acid and marker of liver secretion functions were serially measured. Liver biopsy pre and post decompression was performed for Hepatocyte apoptosis pathologic examination by TUNEL fluorescing, which measured by 2 people in double blinded system. Total bile acid, and liver secretion functions were measured by automated chemistry analyzer. The result of this study shows that twenty one severe obstructive jaundice patients were included. After decompression the hepatocyte apoptosis index decreased from an average of 53.1 (SD 105 to 11.7 (SD 13.6 (p < 0.05. Average of bile acid serum decreased from 96.4 (SD 53.8 to 19.9 (SD 39.5 until 13.0 (SD 12.6 μmol/L (p < 0.05 Total ilirubin decreased from 20.0 (SD 8.9 to 13.3 (SD 5.0 until 6.2 (SD 4.0 mg/dL (p < 0.05, while the phosphates alkaline (ALP and γ-glutamil transpeptidase (γ-GT activities also decreased ignificantly. In conclusion, bile acids accumulation and excessive hepatocyte poptosis through bile duct decompression improve the liver secretion functions by inhibition mechanism.

  13. Insulin inhibits glucagon-induced glycogenolysis normally in perivenous hepatocytes of Wistar fatty rats.

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    Ikezawa, Yoshihiro; Yamatani, Keiichi; Ohnuma, Hiroshi; Daimon, Makoto; Manaka, Hideo; Sasaki, Hideo

    2005-08-01

    Wistar fatty (WF) rats are obese, hyperinsulinemic and hyperglycemic, and thus a model of type 2 diabetes mellitus. Since we have found that insulin specifically inhibits glucagon-induced glycogenolysis in perivenous hepatocytes (PVH) from normal rats, we examined the inhibitory effect of insulin on glucagon-induced glycogenolysis in PVH of hyperinsulinemic WF rats. Basal glucose release was 64.0+/-4.1 nmol/mgprotein/30 min from PVH of lean littermates (WL rats) and 137.0+/-19.3 nmol/mgprotein/30 min from that of WF rats (pglycogenolysis in PVH similarly between WL and WF rats, to 56.7+/-13.3% and to 46.1+/-7.5%, respectively. Thus, the antagonizing effect of insulin on glucagon-induced increase in glycogenolysis was preserved in PVH of hyperinsulinemic and hyperglycemic WF rats.

  14. Signal transduction and downregulation of C-MET in HGF stimulated low and highly metastatic human osteosarcoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Husmann, Knut, E-mail: khusmann@research.balgrist.ch [Laboratory for Orthopedic Research, Department of Orthopedics, Balgrist University Hospital, University of Zurich, Zurich (Switzerland); Ducommun, Pascal [Laboratory for Orthopedic Research, Department of Orthopedics, Balgrist University Hospital, University of Zurich, Zurich (Switzerland); Division of Plastic Surgery and Hand Surgery, Department of Surgery, University Hospital Zurich, Zurich (Switzerland); Sabile, Adam A.; Pedersen, Else-Marie; Born, Walter; Fuchs, Bruno [Laboratory for Orthopedic Research, Department of Orthopedics, Balgrist University Hospital, University of Zurich, Zurich (Switzerland)

    2015-09-04

    The poor outcome of osteosarcoma (OS), particularly in patients with metastatic disease and a five-year survival rate of only 20%, asks for more effective therapeutic strategies targeting malignancy-promoting mechanisms. Dysregulation of C-MET, its ligand hepatocyte growth factor (HGF) and the fusion oncogene product TPR-MET, first identified in human MNNG-HOS OS cells, have been described as cancer-causing factors in human cancers. Here, the expression of these molecules at the mRNA and the protein level and of HGF-stimulated signaling and downregulation of C-MET was compared in the parental low metastatic HOS and MG63 cell lines and the respective highly metastatic MNNG-HOS and 143B and the MG63-M6 and MG63-M8 sublines. Interestingly, expression of TPR-MET was only observed in MNNG-HOS cells. HGF stimulated the phosphorylation of Akt and Erk1/2 in all cell lines investigated, but phospho-Stat3 remained at basal levels. Downregulation of HGF-stimulated Akt and Erk1/2 phosphorylation was much faster in the HGF expressing MG63-M8 cells than in HOS cells. Degradation of HGF-activated C-MET occurred predominantly through the proteasomal and to a lesser extent the lysosomal pathway in the cell lines investigated. Thus, HGF-stimulated Akt and Erk1/2 signaling as well as proteasomal degradation of HGF activated C-MET are potential therapeutic targets in OS. - Highlights: • Expression of TPR-MET was only observed in MNNG-HOS cells. • HGF stimulated the phosphorylation of Akt and Erk1/2 but not of Stat3 in osteosarcoma cell lines. • Degradation of HGF-activated C-MET occurred predominantly through the proteasomal pathway.

  15. Weight loss reversed obesity-induced HGF/c-Met pathway and basal-like breast cancer progression

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    Sneha eSundaram

    2014-07-01

    Full Text Available Epidemiologic studies demonstrate that obesity is associated with an aggressive subtype of breast cancer called basal-like breast cancer (BBC. Using the C3(1-TAg murine model of BBC, we previously demonstrated that mice displayed an early onset of tumors when fed obesogenic diets in the adult window of susceptibility. Obesity was also shown to elevate mammary gland expression and activation of hepatocyte growth factor (HGF/c-Met compared to lean controls, a pro-tumorigenic pathway associated with BBC in patients. Epidemiologic studies estimate that weight loss could prevent a large proportion of BBC. We sought to investigate whether weight loss in adulthood prior to tumor onset would protect mice from accelerated tumorigenesis observed in obese mice. Using a life-long model of obesity, C3(1-TAg mice were weaned onto and maintained on an obesogenic high fat diet. Obese mice displayed significant elevations in tumor progression, but not latency or burden. Tumor progression was significantly reversed when obese mice were induced to lose weight by switching to a control low fat diet prior to tumor onset compared to mice maintained on obesogenic diet. It is likely that other factors regulated tumor progression, hence we investigated the HGF/c-Met pathway known to regulate tumorigenesis. Importantly, HGF/c-Met expression in normal mammary glands and c-Met in tumors was elevated with obesity and was significantly reversed with weight loss. Changes in tumor growth could not be explained by measures of HGF action including phospho-AKT or phospho-S6. Other mediators associated with oncogenesis such as hyperinsulinemia and a high leptin/adiponectin ratio were elevated by obesity and reduced with weight loss. In sum, weight loss significantly blunted the obesity-responsive pro-tumorigenic HGF/c-Met pathway and improved several metabolic risk factors associated with BBC, which together may have contributed to the dramatic reversal of obesity-driven tumor

  16. Cross-arm binding efficiency of an EGFR x c-Met bispecific antibody.

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    Zheng, Songmao; Moores, Sheri; Jarantow, Stephen; Pardinas, Jose; Chiu, Mark; Zhou, Honghui; Wang, Weirong

    2016-01-01

    Multispecific proteins, such as bispecific antibodies (BsAbs), that bind to two different ligands are becoming increasingly important therapeutic agents. Such BsAbs can exhibit markedly increased target binding and target residence time when both pharmacophores bind simultaneously to their targets. The cross-arm binding efficiency (χ) describes an increase in apparent affinity when a BsAb binds to the second target or receptor (R2) following its binding to the first target or receptor (R1) on the same cell. χ is an intrinsic characteristic of a BsAb mostly related to the binding epitopes on R1 and R2. χ can have significant impacts on the binding to R2 for BsAbs targeting two receptors on the same cell. JNJ-61186372, a BsAb that targets epidermal growth factor receptor (EGFR) and c-Met, was used as the model compound for establishing a method to characterize χ. The χ for JNJ-61186372 was successfully determined via fitting of in vitro cell binding data to a ligand binding model that incorporated χ. The model-derived χ value was used to predict the binding of JNJ-61186372 to individual EGFR and c-Met receptors on tumor cell lines, and the results agreed well with the observed IC50 for EGFR and c-Met phosphorylation inhibition by JNJ-61186372. Consistent with the model, JNJ-61186372 was shown to be more effective than the combination therapy of anti-EGFR and anti-c-Met monovalent antibodies at the same dose level in a mouse xenograft model. Our results showed that χ is an important characteristic of BsAbs, and should be considered for rationale design of BsAbs targeting two membrane bound targets on the same cell.

  17. Nitric oxide donor NOR 3 inhibits ketogenesis from oleate in isolated rat hepatocytes by a cyclic GMP-independent mechanism.

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    Nomura, T; Ohtsuki, M; Matsui, S; Sumi-Ichinose, C; Nomura, H; Hagino, Y

    1998-01-01

    Studies were conducted to clarify the effects of nitric oxide donors NOR 3 ((+/-)-(E)-ethyl-2-[(E)-hydroxyimino]-5-nitro-3-hexeneamide, FK409), SIN-1 (3-morpholinosydnonimine) and SNAP (S-nitroso-N-acetylpenicillamine) on the accumulation of cGMP and cAMP and Ca2+ mobilization as well as ketogenesis from oleate in isolated rat hepatocytes. NOR 3 caused inhibition of ketogenesis from oleate along with stimulation of cGMP accumulation in rat hepatocytes, whereas SIN-1 and SNAP exerted no effect on ketogenesis despite their marked stimulation of cGMP accumulation. Although the nitric oxide trapping agent, carboxy-PTIO (2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide), antagonized the stimulation by NOR 3 of cGMP accumulation, it failed to modulate the anti-ketogenic action of NOR 3. Furthermore, neither 8-bromoguanosine-3',5'-cyclic monophosphate nor N2,2'-O-dibutyrylguanosine-3',5'-cyclic monophosphate mimicked the anti-ketogenic action of NOR 3. It is concluded in the present study that NOR 3-induced inhibition of ketogenesis in rat hepatocytes is not mediated by cGMP. The present study revealed that the remaining structure of NOR 3 from which nitric oxide had been spontaneously released had no anti-ketogenic action. We first and clearly demonstrated that nitrite production was dramatically enhanced when NOR 3 was incubated in the presence of rat hepatocytes. The mechanism whereby NOR 3 inhibits ketogenesis in rat hepatocytes will be discussed.

  18. Inducing effects of hepatocyte growth factor on the expression of vascular endothelial growth factor in human colorectal carcinoma cells through MEK and PI3K signaling pathways

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yu-hua; WEI Wei; XU Hao; WANG Yan-yan; WU Wen-xi

    2007-01-01

    Background Vascular endothelial growth factor plays a key role in human colorectal carcinoma invasion and metastasis. However, the regulation mechanism remains unknown. Recent studies have shown that several cytokines can regulate the expression of vascular endothelial growth factor in tumor cells. In this study, we investigated whether hepatocyte growth factor can regulate the expression of vascular endothelial growth factor in colorectal carcinoma cells.Methods Hepatocyte growth factor and vascular endothelial growth factor in human serum were measured by ELISA.The mRNA level of vascular endothelial growth factor was analyzed by reverse transcription-PCR. Western blot assay was performed to evaluate levels of c-Met and several other proteins involved in the MAPK and PI3K signaling pathways in colorectal carcinoma cells.Results Serum hepatocyte growth factor and vascular endothelial growth factor were significantly increased in colorectal carcinoma subjects. In vitro extraneous hepatocyte growth factor markedly increased protein and mRNA levels of vascular endothelial growth factor in colorectal carcinoma cells. Hepatocyte growth factor induced phosphorylation of c-Met, ERK1/2 and AKT in a dose-dependent manner. Specific inhibitors on MEK and PI3K inhibited the hepatocyte growth factor-induced expression of vascular endothelial growth factor in colorectal carcinoma cells.Conclusion This present study indicates that hepatocyte growth factor upregulates the expression of vascular endothelial growth factor in colorectal carcinoma cells via the MEK/ERK and PI3K/AKT signaling pathways.

  19. Vanadate inhibition of hepatocytic autophagy. Calcium-modulated and osmolality-modulated antagonism by asparagine.

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    Fosse, M; Berg, T O; O'Reilly, D S; Seglen, P O

    1995-05-15

    The phosphate analogue vanadate, at 10 mM, strongly (approximately 90%) inhibited the autophagic sequestration of endogenous lactate dehydrogenase in isolated rat hepatocytes. The effect of vanadate was markedly (approximately 80%) antagonized by asparagine (20 mM), and to a lesser extent by glutamine, glycine, and alanine. The antagonism was only observed in the presence of Ca2+ when an isotonic standard incubation medium was used, but by increasing the medium osmolality this Ca2+ requirement could be eliminated. Asparagine induced a cell swelling (17% at 20 mM) that might account for at least part of its vanadate antagonism, since hypotonic cell swelling by itself stimulated autophagy (with a maximal effect at approximately 200 mosM). Conversely, hypertonic media inhibited autophagy and were additive to vanadate. In a strongly hypotonic medium (less than 200 mosM), both asparagine and vanadate were inhibitory. However, since vanadate alone had no effect on cell volume, the vanadate-asparagine antagonism could not be exerted exclusively at the level of cell volume regulation. An additional mechanism might be a partial deamination of asparagine, generating ammonia, which was found to oppose the vanadate inhibition of autophagy while having no effect on cell volume. Other metabolizable amino acids, like alanine and glycine, were moderately vanadate-antagonistic while failing to induce cell swelling. These results are compatible with a vanadate-antagonistic effect of asparagine mediated partly through an unknown mechanism (possibly pH change) by its deamination product, ammonia, partly through cell swelling and a secondary Ca2+ influx that could compensate for a vanadate-induced depletion of intracellular calcium stores.

  20. Correlations of microvascular blood flow of contrast-enhanced ultrasound and HGF/c-Met signaling pathway with clinicopathological features and prognosis of patients with hepatocellular carcinoma

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    Zhuang, Peng-Hui; Xu, Lei; Gao, Lu; Lu, Wei; Ruan, Li-Tao; Yang, Jin

    2017-01-01

    The study is designed to explore the correlations of microvascular blood flow of contrast-enhanced ultrasound (CEUS) and hepatocyte growth factor (HGF)/c-Met signaling pathway with clinicopathological features and prognosis of patients with hepatocellular carcinoma (HCC). One hundred and eighteen patients pathologically diagnosed as primary HCC were selected. All HCC patients underwent CEUS examination before operation. HCC tissues and adjacent normal tissue specimens were obtained to detect the protein rates of HGF and c-Met expressions by immunohistochemistry. The mRNA expressions of HGF and c-Met were detected by quantitative real-time polymerase chase reaction assay. The microvessel density (MVD) was tested by CD34 immunohistochemistry. Compared with liver parenchyma, the HCC lesions had higher MVD, preoperative peak intensity (PI), area under the curve (AUC), lower preoperative time to peak (TTP), and washout time (WOT). Compared with adjacent normal tissues, the protein and mRNA expressions of HGF were reduced in HCC tissues, but the protein and mRNA expressions of c-Met and MVD were increased. The protein expressions of HGF and c-Met exhibited evident correlations with TNM stage, tumor size, vascular invasion, liver cirrhosis, and hepatitis B virus and hepatitis C virus infection of HCC patients. The tumor size and number, vascular invasion, the protein expressions of HGF and c-Met, and MVD were associated with the TTP, PI, WOT, and AUC of CEUS in HCC patients. The protein expressions of HGF and c-Met, MVD and preoperative PI revealed negative associations with the prognosis of HCC patients. In conclusion, quantitative parameters of CEUS and HGF/c-Met signaling pathway-related proteins may be helpful for early diagnosis and prognosis prediction of HCC patients.

  1. Discovery and optimization of novel 4-phenoxy-6,7-disubstituted quinolines possessing semicarbazones as c-Met kinase inhibitors.

    Science.gov (United States)

    Qi, Baohui; Mi, Bin; Zhai, Xin; Xu, Ziyi; Zhang, Xiaolong; Tian, Zeru; Gong, Ping

    2013-09-01

    A novel series of N(1)-(3-fluoro-4-(6,7-disubstituted-quinolin-4-yloxy)phenyl)-N(4)-arylidenesemicarbazide derivatives were synthesized and evaluated for their c-Met kinase inhibition and cytotoxicity against A549, HT-29, MKN-45 and MDA-MB-231 cancer cell lines in vitro. Several potent compounds were further evaluated against three other cancer cell lines (U87MG, NCI-H460 and SMMC7721). Most of compounds tested exhibited moderate to excellent activity. The studies of SARs identified the most promising compound 28 (c-Met IC50=1.4nM) as a c-Met kinase inhibitor. In this study, a promising compound 28 was identified, which displayed 2.1-, 3.3-, 48.4- and 3.6-fold increase against A549, HT-29, U87MG and NCI-H460 cell lines, respectively, compared with that of Foretinib.

  2. Ghrelin Inhibition Restores Glucose Homeostasis in Hepatocyte Nuclear Factor-1α (MODY3)-Deficient Mice.

    Science.gov (United States)

    Brial, François; Lussier, Carine R; Belleville, Karine; Sarret, Philippe; Boudreau, François

    2015-09-01

    Hepatocyte nuclear factor-1α (HNF1α) is a transcription factor expressed in tissues of endoderm origin. Mutations in HNF1A are associated with maturity-onset diabetes of the young 3 (MODY3). Mice deficient for Hnf1α are hyperglycemic, with their pancreatic β-cells being defective in glucose-sensing insulin secretion. The specific mechanisms involved in this defect are unclear. Gut hormones control glucose homeostasis. Our objective was to explore whether changes in these hormones play a role in glucose homeostasis in the absence of Hnf1α. An increase in ghrelin gene transcript and a decrease in glucose-dependent insulinotropic polypeptide (GIP) gene transcripts were observed in the gut of Hnf1α-null mice. These changes correlated with an increase of ghrelin and a decrease of GIP-labeled cells. Ghrelin serological levels were significantly induced in Hnf1α-null mice. Paradoxically, GIP levels were also induced in these mice. Treatment of Hnf1α-null mice with a ghrelin antagonist led to a recovery of the diabetic symptoms. We conclude that upregulation of ghrelin in the absence of Hnf1α impairs insulin secretion and can be reversed by pharmacological inhibition of ghrelin/GHS-R interaction. These observations open up on future strategies to counteract ghrelin action in a program that could become beneficial in controlling non-insulin-dependent diabetes.

  3. Modulating carbonyl cytotoxicity in intact rat hepatocytes by inhibiting carbonyl-metabolizing enzymes. I. Aliphatic alkenals.

    Science.gov (United States)

    Niknahad, Hossein; Siraki, Arno G; Shuhendler, Adam; Khan, Sumsullah; Teng, Shirley; Galati, Giuseppe; Easson, Elaine; Poon, Raymond; O'Brien, Peter J

    2003-02-01

    The cytotoxicity of alkenals towards hepatocytes was related to their electrophilicity not their hydrophobicity as cytotoxicity decreased as the chain length increased from acrolein to hexenal and then cytotoxicity increased from hexenal to nonenal. The sequence of events found was rapid glutathione depletion, lipid peroxidation, and inhibition of respiration before cell lysis occurred. Cytotoxicity markedly increased if glutathione was depleted beforehand. Although acrolein-induced cytotoxicity was only delayed by antioxidants or glycolytic substrates (e.g. fructose), it was prevented by NADH generators (e.g. xylitol and sorbitol) due to increased metabolism by ADH1. Cytotoxicity induced by trans,trans-2,4-decadienal (decadienal), on the other hand, was prevented by antioxidants and/or glycolytic substrates but was not prevented by NADH generators. Decadienal-induced cytotoxicity was also more increased by mitochondrial ALDH2 inhibitors than acrolein and was more increased by decreasing mitochondrial NAD+ with rotenone or decreased by increasing mitochondrial NAD+ with oxaloacetate. This suggests that the high electrophilicity of acrolein makes acrolein a more promiscuous inhibitor than decadienal. This results in the inactivation of more enzymes required for cell viability including the cytosolic and mitochondrial ALDHs as well as other enzymes (e.g. mitochondrial) making the reductive detoxication of acrolein by ADH1 more important than the oxidative detoxification by ALDHs. Decadienal is detoxified by all cytosolic and mitochondrial ALDHs and is less dependent on ADH1 for detoxication. There was also marked cytotoxic synergism between acrolein and decadienal presumably because of ALDH inactivation by acrolein.

  4. Inhibition of bile salt transport by drugs associated with liver injury in primary hepatocytes from human, monkey, dog, rat, and mouse.

    Science.gov (United States)

    Zhang, Jie; He, Kan; Cai, Lining; Chen, Yu-Chuan; Yang, Yifan; Shi, Qin; Woolf, Thomas F; Ge, Weigong; Guo, Lei; Borlak, Jürgen; Tong, Weida

    2016-08-05

    Interference of bile salt transport is one of the underlying mechanisms for drug-induced liver injury (DILI). We developed a novel bile salt transport activity assay involving in situ biosynthesis of bile salts from their precursors in primary human, monkey, dog, rat, and mouse hepatocytes in suspension as well as LC-MS/MS determination of extracellular bile salts transported out of hepatocytes. Glycine- and taurine-conjugated bile acids were rapidly formed in hepatocytes and effectively transported into the extracellular medium. The bile salt formation and transport activities were time‒ and bile-acid-concentration‒dependent in primary human hepatocytes. The transport activity was inhibited by the bile salt export pump (BSEP) inhibitors ketoconazole, saquinavir, cyclosporine, and troglitazone. The assay was used to test 86 drugs for their potential to inhibit bile salt transport activity in human hepatocytes, which included 35 drugs associated with severe DILI (sDILI) and 51 with non-severe DILI (non-sDILI). Approximately 60% of the sDILI drugs showed potent inhibition (with IC50 values drugs showed this strength of inhibition in primary human hepatocytes and these drugs are associated only with cholestatic and mixed hepatocellular cholestatic (mixed) injuries. The sDILI drugs, which did not show substantial inhibition of bile salt transport activity, are likely to be associated with immune-mediated liver injury. Twenty-four drugs were also tested in monkey, dog, rat and mouse hepatocytes. Species differences in potency were observed with mouse being less sensitive than other species to inhibition of bile salt transport. In summary, a novel assay has been developed using hepatocytes in suspension from human and animal species that can be used to assess the potential for drugs and/or drug-derived metabolites to inhibit bile salt transport and/or formation activity. Drugs causing sDILI, except those by immune-mediated mechanism, are highly associated with potent

  5. Cyclic AMP-guanine exchange factor activation inhibits JNK-dependent lipopolysaccharide-induced apoptosis in rat hepatocytes

    Directory of Open Access Journals (Sweden)

    Kathleen Ponzetti

    2010-01-01

    Full Text Available Kathleen Ponzetti1, Melissa King1, Anna Gates1, M Sawkat Anwer2, Cynthia RL Webster11Department of Clinical Science, Tufts Cummings School of Veterinary Medicine, Grafton MA, USA; 2Department of Biomedical Sciences, Tufts Cummings School of Veterinary Medicine, Grafton MA, USAAbstract: Lipopolysaccharide (LPS is known to damage hepatocytes by cytokines released from activated Kupffer cells, but the ancillary role of LPS as a direct hepatotoxin is less well characterized. The aim of this study was to determine the direct effect of LPS on hepatocyte viability and the underlying signaling mechanism. Rat hepatocyte cultures treated overnight with LPS (500 ng/mL induced apoptosis as monitored morphologically (Hoechst 33258 and biochemically (cleavage of caspase 3 and 9 and the appearance of cytochrome C in the cytoplasm. LPS-induced apoptosis was additive to that induced by glycochenodeoxycholate or Fas ligand, was associated with activation of c-Jun N-terminal kinase B (JNK and p38 mitogenactivated protein kinases (MAPK, and inhibition of protein kinase (AKT. Inhibition of JNK by SP600125, but not of p38 MAPK by SB203580 attenuated LPS-induced apoptosis, indicating JNK dependency. CPT-2-Me-cAMP, an activator of cAMP-GEF, decreased apoptosis due to LPS alone or in combination with glycochenodeoxycholate or Fas ligand. CPT-2-Me-cAMP also prevented LPS-induced activation of JNK and inhibition of AKT. Taken together, these results suggest that LPS can induce hepatocyte apoptosis directly in vitro in a JNK-dependent manner and activation of cAMP-GEF protects against the LPS-induced apoptosis most likely by reversing the effect of LPS on JNK and AKT.Keywords: apoptosis, cAMP-GEF, AKT, exchange protein activated by cAMP (EPAC, lipopolysaccharide, JNK

  6. YAP Inhibition Restores Hepatocyte Differentiation in Advanced HCC, Leading to Tumor Regression

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    Julien Fitamant

    2015-03-01

    Full Text Available Defective Hippo/YAP signaling in the liver results in tissue overgrowth and development of hepatocellular carcinoma (HCC. Here, we uncover mechanisms of YAP-mediated hepatocyte reprogramming and HCC pathogenesis. YAP functions as a rheostat in maintaining metabolic specialization, differentiation, and quiescence within the hepatocyte compartment. Increased or decreased YAP activity reprograms subsets of hepatocytes to different fates associated with deregulation of the HNF4A, CTNNB1, and E2F transcriptional programs that control hepatocyte quiescence and differentiation. Importantly, treatment with small interfering RNA-lipid nanoparticles (siRNA-LNPs targeting YAP restores hepatocyte differentiation and causes pronounced tumor regression in a genetically engineered mouse HCC model. Furthermore, YAP targets are enriched in an aggressive human HCC subtype characterized by a proliferative signature and absence of CTNNB1 mutations. Thus, our work reveals Hippo signaling as a key regulator of the positional identity of hepatocytes, supports targeting of YAP using siRNA-LNPs as a paradigm of differentiation-based therapy, and identifies an HCC subtype that is potentially responsive to this approach.

  7. Inhibition of lipid synthesis and secretion in long-term cultures of adult rat hepatocytes by alpha-asarone.

    Science.gov (United States)

    Hernández, A; López, M L; Chamorro, G; Mendoza-Figueroa, T

    1993-04-01

    In this work we studied the effect of alpha-asarone, a hypolipidemic active principle of Guatteria gaumeri Greenman, on hepatic lipid metabolism using adult rat hepatocytes cultured on a feeder layer of 3T3 cells. These cultures synthesize and secrete for at least two weeks various lipids from [14C]-acetic and [14C]-oleic acid. Exposure for one or two weeks to 10 micrograms/ml of alpha-asarone decreased the secretion of various lipids to the culture medium; triacylglycerol secretion was inhibited by 80-97%, phospholipid secretion by 70-87%, cholesterol by 64-70%, and cholesterol esters by 50-92%. The incorporation of [14C]-acetic acid into cellular lipids decreased by 30-81% and that of [14C]-oleic acid into phospholipids by 25-47% whereas the incorporation of [14C]-oleic acid into triglycerides and cholesterol esters increased 3.2 fold and by 28-36%, respectively. Similarly, the activities of glycerol-3-phosphate dehydrogenase and malic enzyme, marker enzymes of glycerolipid and fatty acid synthesis, decreased by 22-50% and 30-76%, respectively. Our results show that the exposure of the 3T3-hepatocyte cultures to micromolar concentrations of alpha-asarone significantly inhibits lipid secretion and probably lipid synthesis. They also suggest that at least part of the hypolipidemic effect could be due to a decrease in the secretion of lipids (i.e., lipoproteins) by the hepatocytes.

  8. EGFR is dispensable for c-Met-mediated proliferation and survival activities in mouse adult liver oval cells.

    Science.gov (United States)

    Martínez-Palacián, A; del Castillo, G; Herrera, B; Fernández, M; Roncero, C; Fabregat, I; Sánchez, A

    2012-02-01

    Liver progenitor cells rise as potential critical players in hepatic regeneration but also carcinogenesis. It is therefore mandatory to define the signals controlling their activation and expansion. Recently, by using a novel in vitro model of oval cell lines expressing a mutant tyrosine kinase-inactive form of c-Met we demonstrated that autocrine c-Met signalling plays an essential role in promoting oval cell survival. Here, we investigated the significance of the epidermal growth factor receptor (EGFR) signalling in oval cell proliferation and survival, as well as a potential functional crosstalk between the c-Met and the EGFR pathways. We found an autocrine activation of the EGFR-triggered pathway in Met(flx/flx) and Met(-/-) oval cells as judged by constitutive expression of the EGFR ligands, transforming growth factor-alpha (TGF-α) and heparin-binding EGF like growth factor (HB-EGF), and activation of EGFR. On the other hand, treatment with AG1478, a specific inhibitor of EGFR, effectively blocked endogenous and EGF-induced proliferation, while increased serum withdrawal and transforming growth factor-beta (TGF-β)-induced apoptosis. These results suggest that constitutively activated EGFR might promote oval cell proliferation and survival. We found that hepatocyte growth factor (HGF) does not transactivate EGFR nor EGF transactivates c-Met. Furthermore, treatment with AG1478 or EGFR gene silencing did not interfere with HGF-mediated activation of target signals, such as protein kinase B (AKT/PKB), and extracellular signal-regulated kinases 1/2 (ERK 1/2), nor did it have any effect on HGF-induced proliferative and antiapoptotic activities in Met(flx/flx) cells, showing that HGF does not require EGFR activation to mediate such responses. EGF induced proliferation and survival equally in Met(flx/flx) and Met(-/-) oval cells, proving that EGFR signalling does not depend on c-Met tyrosine kinase activity. Together, our results provide strong evidence that in

  9. WNT5A inhibits hepatocyte proliferation and concludes β-catenin signaling in liver regeneration.

    Science.gov (United States)

    Yang, Jing; Cusimano, Antonella; Monga, Jappmann K; Preziosi, Morgan E; Pullara, Filippo; Calero, Guillermo; Lang, Richard; Yamaguchi, Terry P; Nejak-Bowen, Kari N; Monga, Satdarshan P

    2015-08-01

    Activation of Wnt/β-catenin signaling during liver regeneration (LR) after partial hepatectomy (PH) is observed in several species. However, how this pathway is turned off when hepatocyte proliferation is no longer required is unknown. We assessed LR in liver-specific knockouts of Wntless (Wls-LKO), a protein required for Wnt secretion from a cell. When subjected to PH, Wls-LKO showed prolongation of hepatocyte proliferation for up to 4 days compared with littermate controls. This coincided with increased β-catenin-T-cell factor 4 interaction and cyclin-D1 expression. Wls-LKO showed decreased expression and secretion of inhibitory Wnt5a during LR. Wnt5a expression increased between 24 and 48 hours, and Frizzled-2 between 24 and 72 hours, after PH in normal mice. Treatment of primary mouse hepatocytes and liver tumor cells with Wnt5a led to a notable decrease in β-catenin-T-cell factor activity, cyclin-D1 expression, and cell proliferation. Intriguingly, Wnt5a-LKO did not display any prolongation of LR because of compensation by other cells. In addition, Wnt5a-LKO hepatocytes failed to respond to exogenous Wnt5a treatment in culture because of a compensatory decrease in Frizzled-2 expression. In conclusion, we demonstrate Wnt5a to be, by default, a negative regulator of β-catenin signaling and hepatocyte proliferation, both in vitro and in vivo. We also provide evidence that the Wnt5a/Frizzled-2 axis suppresses β-catenin signaling in hepatocytes in an autocrine manner, thereby contributing to timely conclusion of the LR process.

  10. Dicer-Dependent Production of MicroRNA221 in Hepatocytes Inhibits p27 and is Required for Liver Regeneration in Mice.

    Science.gov (United States)

    Oya, Yuki; Masuzaki, Ryota; Tsugawa, Daisuke; Ray, Kevin C; Dou, Yongchao; Karp, Seth J

    2017-02-23

    Dicer processes microRNAs (miRs) into active forms in a wide variety of tissues including the liver. To determine the role of Dicer in liver regeneration, we performed a series of in vivo and in vitro studies in a murine 2/3 hepatectomy model. Dicer was downregulated after 2/3 hepatectomy, and loss of Dicer inhibited liver regeneration associated with decreased cyclin A2 and miR-221, and increased levels of the cell cycle inhibitor p27. In vitro, miR-221 inhibited p27 production in primary hepatocytes and increased hepatocyte proliferation. Specific reconstitution of miR-221 in hepatocyte-specific Dicer null mice inhibited p27 and restored liver regeneration. In wild type mice, targeted inhibition of miR-221 using a cholesterol-conjugated anti-miR-221 inhibited hepatocyte proliferation after 2/3 hepatectomy. These results identify Dicer production of miR-221 as an essential component of a miRNA-dependent mechanism for suppression of p27 that controls the rate of hepatocyte proliferation after partial hepatectomy.

  11. The tyrosine kinase receptor c-met, its cognate ligand HGF and the tyrosine kinase receptor trasducers STAT3, PI3K and RHO in thyroid nodules associated with Hashimoto's thyroiditis: an immunohistochemical characterization

    Directory of Open Access Journals (Sweden)

    R. M. Ruggeri

    2010-06-01

    Full Text Available Hepatocyte growth factor (HGF exerts proliferative activities in thyrocytes upon binding to its tyrosine kinase receptor c-met and is also expressed in benign thyroid nodules as well as in Hashimoto’s thyroiditis (HT. The simultaneous expression of HGF/c-met and three trasducers of tyrosine kinase receptors (STAT3, PI3K, RHO in both the nodular and extranodular tissues were studied by immunohistochemistry in 50 benign thyroid nodules (NGs, 25 of which associated with HT. The ligand/tyrosine kinase receptor pair HGF/c-met and the two trasducers PI3K and RHO were expressed in NGs, regardless of association with HT, with a higher positive cases percentage in HT-associated NGs compared to not HT-associated NGs (25/25 or 100% vs 7/25 or 28%; P<0.001. HGF, PI3K and RHO expression was only stromal (fibroblasts and endothelial cells, in all 32 reactive NGs, while c-met localization was consistently epithelial (thyrocyes. Immu­noreactions for HGF, c-met, PI3K and RHO were also apparent in the extra-nodular tissue of HT specimens, where HGF and PI3K were expressed not only in stromal cells but also in thyrocyes along with the c-met. Finally, a positive correlation was observed between the proportion of HGF, c-met, PI3K follicular cells and the grade of lymphoid aggregates in HT. In conclusion, HGF, c-met, PI3K are much more frequently and highly expressed in HT compared to NGs, and among all NGs in those present in the context of HT. A paracrine effect of HFG/c-met on nodule development, based on the prevalent stromal expression, may be suggested along with a major role of HGF/c-met and PI3K in HT. Finally, the expression of such molecules in HT may be regulated by lymphoid infiltrate.

  12. Activation of c-Met and upregulation of CD44 expression are associated with the metastatic phenotype in the colorectal cancer liver metastasis model.

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    Victoria A Elliott

    Full Text Available BACKGROUND: Liver metastasis is the most common cause of death in patients with colorectal cancer. Despite extensive research into the biology of cancer progression, the molecular mechanisms that drive colorectal cancer metastasis are not well characterized. METHODS: HT29 LM1, HT29 LM2, HT29 LM3 cell lines were derived from the human colorectal cancer cell line HT29 following multiple rounds of in vivo selection in immunodeficient mice. RESULTS: CD44 expression, a transmembrane glycoprotein involved in cell-cell and cell-matrix adhesions, and cancer cells adhesion to endothelial cells was increased in all in vivo selected cell lines, with maximum CD44 expression and cancer cells adhesion to endothelial cells in the highly metastatic HT29 LM3 cell line. Activation of c-Met upon hepatocyte growth factor (HGF stimulation in the in vivo selected cell lines is CD44 independent. In vitro separation of CD44 high and low expression cells from HT29 LM3 cell line with FACS sorting confirmed that c-Met activation is CD44 independent upon hepatocyte growth factor stimulation. Furthermore, in vivo evaluation of CD44 low and high expressing HT29 LM3 cells demonstrated no difference in liver metastasis penetrance. CONCLUSIONS: Taken together, our findings indicate that the aggressive metastatic phenotype of in vivo selected cell lines is associated with overexpression of CD44 and activation of c-MET. We demonstrate that c-Met activation is CD44 independent upon hepatocyte growth factor stimulation and confirm that CD44 expression in HT29 LM3 cell line is not responsible for the increase in metastatic penetrance in HT29 LM3 cell line.

  13. Dynamic expression and localization of c-MET isoforms in the developing rat pancreas.

    Science.gov (United States)

    Wu, Yulong; Cheng, Mei; Shi, Zhen; Feng, Zhenqing; Guan, Xiaohong

    2014-01-01

    Pancreata from Sprague Dawley rats of different developmental stages were studied to determine the expression and cellular localization of different c-MET isoforms in the developing rat pancreas. Pancreatic mRNA and protein expression levels of c-MET at different developmental stages from embryo to adult were detected by reverse transcription-polymerase chain reaction and by western blotting. To identify the cellular localization of c-MET protein in the developing rat pancreas, double immunofluorescent staining was performed using antibodies for cell type-specific markers and for c-MET. The expression of two isoforms of c-MET (190 kDa and 170 kDa) coincided with the development of the pancreas. The 190 kDa isoform of c-MET is expressed during embryonic stages, and its expression is replaced by the expression of the 170 kDa isoform as the pancreas develops. Only the 170 kDa isoform is expressed in the adult rat pancreas. Throughout all stages of pancreatic development, c-MET is expressed by vimentin-positive cells. In contrast, c-MET staining was stronger in rat pancreata from newborn to adult stages and overlapped with insulin-positive beta-cells. The dynamic expression and localization of different c-MET isoforms in the rat pancreas during different developmental stages indicates that distinct c-MET isoform might be involved in different aspects of pancreatic development.

  14. The sonic hedgehog signaling pathway stimulates anaplastic thyroid cancer cell motility and invasiveness by activating Akt and c-Met.

    Science.gov (United States)

    Williamson, Ashley J; Doscas, Michelle E; Ye, Jin; Heiden, Katherine B; Xing, Mingzhao; Li, Yi; Prinz, Richard A; Xu, Xiulong

    2016-03-01

    The sonic hedgehog (Shh) pathway is highly activated in thyroid neoplasms and promotes thyroid cancer stem-like cell phenotype, but whether the Shh pathway regulates thyroid tumor cell motility and invasiveness remains unknown. Here, we report that the motility and invasiveness of two anaplastic thyroid tumor cell lines, KAT-18 and SW1736, were inhibited by two inhibitors of the Shh pathway (cyclopamine and GANT61). Consistently, the cell motility and invasiveness was decreased by Shh and Gli1 knockdown, and was increased by Gli1 overexpression in KAT-18 cells. Mechanistic studies revealed that Akt and c-Met phosphorylation was decreased by a Gli1 inhibitor and by Shh and Gli1 knockdown, but was increased by Gli1 overexpression. LY294002, a PI-3 kinase inhibitor, and a c-Met inhibitor inhibited the motility and invasiveness of Gli1-transfected KAT-18 cells more effectively than the vector-transfected cells. Knockdown of Snail, a transcription factor regulated by the Shh pathway, led to decreased cell motility and invasiveness in KAT-18 and SW1736 cells. However, key epithelial-to-mesenchymal transition (EMT) markers including E-cadherin and vimentin as well as Slug were not affected by cyclopamine and GANT61 in either SW1736 or WRO82, a well differentiated follicular thyroid carcinoma cell line. Our data suggest that the Shh pathway-stimulated thyroid tumor cell motility and invasiveness is largely mediated by AKT and c-Met activation with little involvement of EMT.

  15. Inhibition of Hepatocyte Apoptosis: An Important Mechanism of Corn Peptides Attenuating Liver Injury Induced by Ethanol.

    Science.gov (United States)

    Ma, Zhili; Hou, Tao; Shi, Wen; Liu, Weiwei; He, Hui

    2015-09-11

    In this study, the effects of mixed corn peptides and synthetic pentapeptide (QLLPF) on hepatocyte apoptosis induced by ethanol were investigated in vivo. QLLPF, was previously characterized from corn protein hydrolysis, which had been shown to exert good facilitating alcohol metabolism activity. Mice were pre-treated with the mixed corn peptides and the pentapeptide for 1 week and then treated with ethanol. After treatment of three weeks, the biochemical indices and the key ethanol metabolizing enzymes, the serum TNF-α, liver TGF-β1 concentrations and the protein expressions related to apoptosis were determined. We found that the Bcl-2, Bax and cytochrome c expressions in the intrinsic pathway and the Fas, FasL and NF-κB expressions in the extrinsic pathway together with higher TNF-α and TGF-β1 concentrations were reversed compared with the model group by both the mixed corn peptides and the pentapeptide. The activation of caspase3 was also suppressed. Additionally, apoptosis was further confirmed with terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and the TUNEL assay demonstrated peptides suppressed hepatocyte apoptosis. Our results suggest that apoptosis induced by ethanol is alleviated in response to the treatment of corn peptides, potentially due to reversing the related protein expression.

  16. Pertussis toxin, an inhibitor of G(αi PCR, inhibits bile acid- and cytokine-induced apoptosis in primary rat hepatocytes.

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    Golnar Karimian

    Full Text Available Excessive hepatocyte apoptosis is a common event in acute and chronic liver diseases leading to loss of functional liver tissue. Approaches to prevent apoptosis have therefore high potential for the treatment of liver disease. G-protein coupled receptors (GPCR play crucial roles in cell fate (proliferation, cell death and act through heterotrimeric G-proteins. G(αiPCRs have been shown to regulate lipoapoptosis in hepatocytes, but their role in inflammation- or bile acid-induced apoptosis is unknown. Here, we analyzed the effect of inhibiting G(αiPCR function, using pertussis toxin (PT, on bile acid- and cytokine-induced apoptosis in hepatocytes. Primary rat hepatocytes, HepG2-rNtcp cells (human hepatocellular carcinoma cells or H-4-II-E cells (rat hepatoma cells were exposed to glycochenodeoxycholic acid (GCDCA or tumor necrosis factor-α (TNFα/actinomycin D (ActD. PT (50-200 nmol/L was added 30 minutes prior to the apoptotic stimulus. Apoptosis (caspase-3 activity, acridine orange staining and necrosis (sytox green staining were assessed. PT significantly reduced GCDCA- and TNFα/ActD-induced apoptosis in rat hepatocytes (-60%, p<0.05 in a dose-dependent manner (with no shift to necrosis, but not in HepG2-rNtcp cells or rat H-4-II-E cells. The protective effect of pertussis toxin was independent of the activation of selected cell survival signal transduction pathways, including ERK, p38 MAPK, PI3K and PKC pathways, as specific protein kinase inhibitors did not reverse the protective effects of pertussis toxin in GCDCA-exposed hepatocytes.Pertussis toxin, an inhibitor of G(αiPCRs, protects hepatocytes, but not hepatocellular carcinoma cells, against bile acid- and cytokine-induced apoptosis and has therapeutic potential as primary hepatoprotective drug, as well as adjuvant in anti-cancer therapy.

  17. Inhibition of NADPH-cytochrome P450 reductase by tannic acid in rat liver microsomes and primary hepatocytes: methodological artifacts and application to ischemia-reperfusion injury.

    Science.gov (United States)

    Pillai, Venkateswaran C; Mehvar, Reza

    2011-08-01

    Tannic acid (TA) inhibits nicotinamide adenine dinucleotide phosphate (NADPH)-cytochrome P450 reductase (CPR) activity, which is measured by reduction of cytochrome c, in rat liver microsomes (RLMs). In the current study, we noticed that TA directly reduces cytochrome c in the absence of microsomes, thus confounding the CPR activity assay. A method is presented that measures CPR activity in the presence of TA by subtracting the cytochrome c reduction in the absence of NADPH (TA effect) from that in the presence of NADPH (TA plus CPR effect). The method was used to determine the inhibitory effect of TA in RLMs, recombinant CPR enzyme, and primary hepatocytes. Additionally, application of TA in a study of role of CPR in a primary rat hepatocyte model of ischemia-reperfusion (IR) was investigated. TA showed concentration-dependent, complete inhibition of CPR with half maximal inhibitory concentration (IC(50) ) values of 58.2 μM in RLMs and 54.6 and 275 μM in primary rat hepatocytes in the absence and presence of serum in the medium, respectively. Additionally, inhibition of CPR by TA was associated with a significant reduction in reactive oxygen species and cell death after IR injury. These data may be useful in future studies using TA as an inhibitor of CPR in microsomes and primary hepatocytes.

  18. The transcriptional activity of hepatocyte nuclear factor 4 alpha is inhibited via phosphorylation by ERK1/2

    Science.gov (United States)

    Bacquet, Caroline; Kiss, Judit; Sipeki, Szabolcs; Martin, Ludovic; Buday, László; Bálint, Bálint L.; Arányi, Tamás

    2017-01-01

    Hepatocyte nuclear factor 4 alpha (HNF4α) nuclear receptor is a master regulator of hepatocyte development, nutrient transport and metabolism. HNF4α is regulated both at the transcriptional and post-transcriptional levels by different mechanisms. Several kinases (PKA, PKC, AMPK) were shown to phosphorylate and decrease the activity of HNF4α. Activation of the ERK1/2 signalling pathway, inducing proliferation and survival, inhibits the expression of HNF4α. However, based on our previous results we hypothesized that HNF4α is also regulated at the post-transcriptional level by ERK1/2. Here we show that ERK1/2 is capable of directly phosphorylating HNF4α in vitro at several phosphorylation sites including residues previously shown to be targeted by other kinases, as well. Furthermore, we also demonstrate that phosphorylation of HNF4α leads to a reduced trans-activational capacity of the nuclear receptor in luciferase reporter gene assay. We confirm the functional relevance of these findings by demonstrating with ChIP-qPCR experiments that 30-minute activation of ERK1/2 leads to reduced chromatin binding of HNF4α. Accordingly, we have observed decreasing but not disappearing binding of HNF4α to the target genes. In addition, 24-hour activation of the pathway further decreased HNF4α chromatin binding to specific loci in ChIP-qPCR experiments, which confirms the previous reports on the decreased expression of the HNF4a gene due to ERK1/2 activation. Our data suggest that the ERK1/2 pathway plays an important role in the regulation of HNF4α-dependent hepatic gene expression. PMID:28196117

  19. Activation of the constitutive androstane receptor inhibits gluconeogenesis without affecting lipogenesis or fatty acid synthesis in human hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Lynch, Caitlin; Pan, Yongmei; Li, Linhao [Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD 21201 (United States); Heyward, Scott; Moeller, Timothy [Bioreclamation In Vitro Technologies, Baltimore, MD 21227 (United States); Swaan, Peter W. [Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD 21201 (United States); Wang, Hongbing, E-mail: hwang@rx.umaryland.edu [Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD 21201 (United States)

    2014-08-15

    Objective: Accumulating evidence suggests that activation of mouse constitutive androstane receptor (mCAR) alleviates type 2 diabetes and obesity by inhibiting hepatic gluconeogenesis, lipogenesis, and fatty acid synthesis. However, the role of human (h) CAR in energy metabolism is largely unknown. The present study aims to investigate the effects of selective hCAR activators on hepatic energy metabolism in human primary hepatocytes (HPH). Methods: Ligand-based structure–activity models were used for virtual screening of the Specs database ( (www.specs.net)) followed by biological validation in cell-based luciferase assays. The effects of two novel hCAR activators (UM104 and UM145) on hepatic energy metabolism were evaluated in HPH. Results: Real-time PCR and Western blotting analyses reveal that activation of hCAR by UM104 and UM145 significantly repressed the expression of glucose-6-phosphatase and phosphoenolpyruvate carboxykinase, two pivotal gluconeogenic enzymes, while exerting negligible effects on the expression of genes associated with lipogenesis and fatty acid synthesis. Functional experiments show that UM104 and UM145 markedly inhibit hepatic synthesis of glucose but not triglycerides in HPH. In contrast, activation of mCAR by 1,4-bis[2-(3,5-dichloropyridyloxy)]benzene, a selective mCAR activator, repressed the expression of genes associated with gluconeogenesis, lipogenesis, and fatty acid synthesis in mouse primary hepatocytes, which were consistent with previous observations in mouse model in vivo. Conclusion: Our findings uncover an important species difference between hCAR and mCAR in hepatic energy metabolism, where hCAR selectively inhibits gluconeogenesis without suppressing fatty acid synthesis. Implications: Such species selectivity should be considered when exploring CAR as a potential therapeutic target for metabolic disorders. - Highlights: • Novel hCAR activators were identified by computational and biological approaches. • The role

  20. A Schisandra-Derived Compound Schizandronic Acid Inhibits Entry of Pan-HCV Genotypes into Human Hepatocytes

    Science.gov (United States)

    Qian, Xi-Jing; Zhang, Xiao-Lian; Zhao, Ping; Jin, Yong-Sheng; Chen, Hai-Sheng; Xu, Qing-Qiang; Ren, Hao; Zhu, Shi-Ying; Tang, Hai-Lin; Zhu, Yong-Zhe; Qi, Zhong-Tian

    2016-01-01

    Despite recent progress in the development of hepatitis C virus (HCV) inhibitors, cost-effective antiviral drugs, especially among the patients receiving liver transplantations, are still awaited. Schisandra is a traditional medicinal herb used to treat a range of liver disorders including hepatitis for thousands of years in China. To isolate the bioactive compounds of schisandra for the treatment of HCV infection, we screened a schisandra-extracts library and identified a tetracyclic triterpenoid, schizandronic acid (SZA), as a novel HCV entry inhibitor. Our findings suggested that SZA potently inhibited pan-HCV genotype entry into hepatoma cells and primary human hepatocytes without interfering virus binding on cell surface or internalization. However, virion-cell fusion process was impaired in the presence of SZA, along with the increased host membrane fluidity. We also found that SZA inhibited the spread of HCV to the neighboring cells, and combinations of SZA with interferon or telaprevir resulted in additive synergistic effect against HCV. Additionally, SZA diminished the establishment of HCV infection in vivo. The SZA target is different from conventional direct-acting antiviral agents, therefore, SZA is a potential therapeutic compound for the development of effective HCV entry inhibitors, especially for patients who need to prevent HCV reinfection during the course of liver transplantations. PMID:27252043

  1. The role of cMet in non-small cell lung cancer resistant to EGFR-inhibitors: did we really find the target?

    Science.gov (United States)

    Passiglia, Francesco; Van Der Steen, Nele; Raez, Luis; Pauwels, Patrick; Gil-Bazo, Ignacio; Santos, Edgardo; Santini, Daniele; Tesoriere, Giovanni; Russo, Antonio; Bronte, Giuseppe; Zwaenepoel, Karen; Cappuzzo, Federico; Rolfo, Christian

    2014-01-01

    The advent of the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) represented the most important innovation in NSCLC treatment over the last years. However, despite a great initial activity, secondary mutations in the same target, or different alterations in other molecular pathways, inevitably occur, leading to the emergence of acquired resistance, in median within the first year of treatment. In this scenario, the mesenchymal-epidermal transition (cMET) tyrosine kinase receptor and its natural ligand, the hepatocyte growth factor (HGF), seem to play an important role. Indeed either the overexpression or the amplification of cMET, as well as the overexpression of the HGF, have been reported in a substantial subgroup of NSCLC patients resistant to EGFR-TKIs. Several cMET-inhibitors have been developed as potential therapeutic candidates, and are currently under investigation in clinical trials. These compounds include both monoclonal antibodies and TKIs, and most of them have been investigated as dual combinations including an anti-EGFR TKI, to improve the efficacy of the available treatments, and ultimately overcome acquired resistance to EGFR-inhibitors.

  2. IL-1β inhibits β-Klotho expression and FGF19 signaling in hepatocytes.

    Science.gov (United States)

    Zhao, Yueshui; Meng, Chenling; Wang, Yang; Huang, Huihui; Liu, Wenjing; Zhang, Jin-Fang; Zhao, Hui; Feng, Bo; Leung, Po Sing; Xia, Yin

    2016-02-15

    Fibroblast growth factor (FGF) 19 is a member of the FGF15/19 subfamily of FGFs that includes FGF15/19, FGF21, and FGF23. FGF19 has been shown to have profound effects on liver metabolism and regeneration. FGF19 binds to FGFR4 and its coreceptor β-Klotho to activate intracellular kinases, including Erk1/2. Studies have shown that proinflammatory cytokines such as TNFα impair FGF21 signaling in adipose cells by repressing β-Klotho expression. However, little is known about the effects of inflammation on the FGF19 pathway in the liver. In the present study, we found that lipopolysaccharide (LPS) inhibited β-Klotho and Fgfr4 expression in livers in mice, whereas LPS had no effects on the two FGF19 receptors in Huh-7 and HepG2 cells. Of the three inflammatory cytokines TNFα, IL-1β, and IL-6, IL-1β drastically inhibited β-Klotho expression, whereas TNFα and IL-6 had no or minor effects. None of the three cytokines had any effects on FGFR4 expression. IL-1β directly inhibited β-Klotho transcription, and this inhibition required both the JNK and NF-κB pathways. In addition, IL-1β inhibited FGF19-induced Erk1/2 activation and cell proliferation. These results suggest that inflammation and IL-1β play an important role in regulating FGF19 signaling and function in the liver.

  3. Obesity-mediated regulation of HGF/c-Met is associated with reduced basal-like breast cancer latency in parous mice.

    Directory of Open Access Journals (Sweden)

    Sneha Sundaram

    Full Text Available It is widely thought that pregnancy reduces breast cancer risk, but this lacks consideration of breast cancer subtypes. While a full term pregnancy reduces risk for estrogen receptor positive (ER+ and luminal breast cancers, parity is associated with increased risk of basal-like breast cancer (BBC subtype. Basal-like subtypes represent less than 10% of breast cancers and are highly aggressive, affecting primarily young, African American women. Our previous work demonstrated that high fat diet-induced obesity in nulliparous mice significantly blunted latency in C3(1-TAg mice, a model of BBC, potentially through the hepatocyte growth factor (HGF/c-Met oncogenic pathway. Experimental studies have examined parity and obesity individually, but to date, the joint effects of parity and obesity have not been studied. We investigated the role of obesity in parous mice on BBC. Parity alone dramatically blunted tumor latency compared to nulliparous controls with no effects on tumor number or growth, while obesity had only a minor role in further reducing latency. Obesity-associated metabolic mediators and hormones such as insulin, estrogen, and progesterone were not significantly regulated by obesity. Plasma IL-6 was also significantly elevated by obesity in parous mice. We have previously reported a potential role for stromal-derived hepatocyte growth factor (HGF via its cognate receptor c-Met in the etiology of obesity-induced BBC tumor onset and in both human and murine primary coculture models of BBC-aggressiveness. Obesity-associated c-Met concentrations were 2.5-fold greater in normal mammary glands of parous mice. Taken together, our studies demonstrate that, parity in C3(1-TAg mice dramatically reduced BBC latency compared to nulliparous mice. In parous mice, c-Met is regulated by obesity in unaffected mammary gland and is associated with tumor onset. C3(1-TAg mice recapitulate epidemiologic findings such that parity drives increased BBC risk and

  4. Hepatocyte Growth Factor from a Clinical Perspective: A Pancreatic Cancer Challenge

    Energy Technology Data Exchange (ETDEWEB)

    Rizwani, Wasia [Department of Biochemistry, Osmania University, Hyderabad, Telangana 500007 (India); Allen, Amanda E.; Trevino, Jose G., E-mail: Jose.Trevino@surgery.ufl.edu [Department of Surgery, University of Florida, 1600 SW Archer Rd, Rm 6175, P.O. Box 100109, Gainesville, FL 32610 (United States)

    2015-09-03

    Pancreatic cancer is the fourth leading cause of cancer-related deaths in the United States and incidence rates are rising. Both detection and treatment options for pancreatic cancer are limited, providing a less than 5% five-year survival advantage. The need for new biomarkers for early detection and treatment of pancreatic cancer demands the efficient translation of bench knowledge to provide clinical benefit. One source of therapeutic resistance is the pancreatic tumor microenvironment, which is characterized by desmoplasia and hypoxia making it less conducive to current therapies. A major factor regulating desmoplasia and subsequently promoting chemoresistance in pancreatic cancer is hepatocyte growth factor (HGF), the sole ligand for c-MET (mesenchymal-epithelial transition), an epithelial tyrosine kinase receptor. Binding of HGF to c-MET leads to receptor dimerization and autophosphorylation resulting in the activation of multiple cellular processes that support cancer progression. Inhibiting activation of c-MET in cancer cells, in combination with other approaches for reducing desmoplasia in the tumor microenvironment, might significantly improve the success of chemotherapy. Therefore, HGF makes a potent novel target for developing therapeutic strategies in combination with existing drugs for treating pancreatic adenocarcinoma. This review provides a comprehensive analysis of HGF and its promising potential as a chemotherapeutic target for pancreatic cancer.

  5. Lipopolysaccharide preconditioning protects hepatocytes from ischemia/reperfusion injury (IRI through inhibiting ATF4-CHOP pathway in mice.

    Directory of Open Access Journals (Sweden)

    Jianhua Rao

    consistent with results of LPS preconditioning in macrophages. CONCLUSIONS: This work is the first time to provide evidence for LPS preconditioning protects hepatocytes from IRI through inhibiting ATF4-CHOP pathway, which may be critical to reducing related apoptosis molecules and modulating innate inflammation.

  6. Mechanism of Hepatocyte Growth Factor Inhibition of Angiotensin II-induced Apoptosis in Primary Lung Cells

    Science.gov (United States)

    2010-02-19

    joints. In addition, they may experience enlargement and bulb-like development of the fingertips and nails , a condition called clubbing [41]. Clinical...2 family, which act to regulate the permeability of the mitochondrial membrane and its release of cytochrome . Initiator caspase 9 is activated in...either a Bax channel blocker (BCB) or a Bax inhibiting peptide (V-5), while a control peptide had no effect (Fig 3B). We found that cell permeable

  7. Loss of HGF/c-Met signaling in pancreatic β-cells leads to incomplete maternal β-cell adaptation and gestational diabetes mellitus.

    Science.gov (United States)

    Demirci, Cem; Ernst, Sara; Alvarez-Perez, Juan C; Rosa, Taylor; Valle, Shelley; Shridhar, Varsha; Casinelli, Gabriella P; Alonso, Laura C; Vasavada, Rupangi C; García-Ocana, Adolfo

    2012-05-01

    Hepatocyte growth factor (HGF) is a mitogen and insulinotropic agent for the β-cell. However, whether HGF/c-Met has a role in maternal β-cell adaptation during pregnancy is unknown. To address this issue, we characterized glucose and β-cell homeostasis in pregnant mice lacking c-Met in the pancreas (PancMet KO mice). Circulating HGF and islet c-Met and HGF expression were increased in pregnant mice. Importantly, PancMet KO mice displayed decreased β-cell replication and increased β-cell apoptosis at gestational day (GD)15. The decreased β-cell replication was associated with reductions in islet prolactin receptor levels, STAT5 nuclear localization and forkhead box M1 mRNA, and upregulation of p27. Furthermore, PancMet KO mouse β-cells were more sensitive to dexamethasone-induced cytotoxicity, whereas HGF protected human β-cells against dexamethasone in vitro. These detrimental alterations in β-cell proliferation and death led to incomplete maternal β-cell mass expansion in PancMet KO mice at GD19 and early postpartum periods. The decreased β-cell mass was accompanied by increased blood glucose, decreased plasma insulin, and impaired glucose tolerance. PancMet KO mouse islets failed to upregulate GLUT2 and pancreatic duodenal homeobox-1 mRNA, insulin content, and glucose-stimulated insulin secretion during gestation. These studies indicate that HGF/c-Met signaling is essential for maternal β-cell adaptation during pregnancy and that its absence/attenuation leads to gestational diabetes mellitus.

  8. Sequence-defined cMET/HGFR-targeted Polymers as Gene Delivery Vehicles for the Theranostic Sodium Iodide Symporter (NIS) Gene.

    Science.gov (United States)

    Urnauer, Sarah; Morys, Stephan; Krhac Levacic, Ana; Müller, Andrea M; Schug, Christina; Schmohl, Kathrin A; Schwenk, Nathalie; Zach, Christian; Carlsen, Janette; Bartenstein, Peter; Wagner, Ernst; Spitzweg, Christine

    2016-08-01

    The sodium iodide symporter (NIS) as well-characterized theranostic gene represents an outstanding tool to target different cancer types allowing noninvasive imaging of functional NIS expression and therapeutic radioiodide application. Based on its overexpression on the surface of most cancer types, the cMET/hepatocyte growth factor receptor serves as ideal target for tumor-selective gene delivery. Sequence-defined polymers as nonviral gene delivery vehicles comprising polyethylene glycol (PEG) and cationic (oligoethanoamino) amide cores coupled with a cMET-binding peptide (cMBP2) were complexed with NIS-DNA and tested for receptor-specificity, transduction efficiency, and therapeutic efficacy in hepatocellular cancer cells HuH7. In vitro iodide uptake studies demonstrated high transduction efficiency and cMET-specificity of NIS-encoding polyplexes (cMBP2-PEG-Stp/NIS) compared to polyplexes without targeting ligand (Ala-PEG-Stp/NIS) and without coding DNA (cMBP2-PEG-Stp/Antisense-NIS). Tumor recruitment and vector biodistribution were investigated in vivo in a subcutaneous xenograft mouse model showing high tumor-selective iodide accumulation in cMBP2-PEG-Stp/NIS-treated mice (6.6 ± 1.6% ID/g (123)I, biological half-life 3 hours) by (123)I-scintigraphy. Therapy studies with three cycles of polyplexes and (131)I application resulted in significant delay in tumor growth and prolonged survival. These data demonstrate the enormous potential of cMET-targeted sequence-defined polymers combined with the unique theranostic function of NIS allowing for optimized transfection efficiency while eliminating toxicity.

  9. Decorin is down-regulated in multiple myeloma and MGUS bone marrow plasma and inhibits HGF-induced myeloma plasma cell viability and migration

    DEFF Research Database (Denmark)

    Kristensen, Ida Bruun; Pedersen, Lise Mariager; Rø, Torstein Baade;

    2013-01-01

    OBJECTIVES: Decorin is a stromal-produced small leucine-rich proteoglycan known to attenuate tumour pro-survival, migration, proliferation and angiogenic signalling pathways. Recent studies have shown that decorin interacts with the hepatocyte growth factor (HGF) receptor c-Met, a potential key p...... of decorin to inhibit HGF-induced effects on MM cell lines were analysed in vitro using cell viability and Transwell migration assays. RESULTS: We found that decorin concentrations were significantly higher (p...

  10. Deguelin action involves c-Met and EGFR signaling pathways in triple negative breast cancer cells.

    Directory of Open Access Journals (Sweden)

    Rajeshwari Mehta

    Full Text Available BACKGROUND: Treatment of breast cancer patients with antiestrogens and aromatase inhibitor(s or Herceptin have shown significant success in steroid receptor positive or Her-2+ breast cancers respectively. However, choice of treatments for breast cancer patients with negative status for estrogen, progesterone receptors and HER2/neu is limited. As a result, search for appropriate therapy regimen for these triple negative breast cancers (TNBC has become a major focus of investigations for many laboratories. Recently, Deguelin, a natural product isolated from African plant Mundulea sericea (Leguminossae has shown both antiproliferative actions in various cancers including breast as well as chemoprenventive activity against carcinogen induced experimental cancers. In this report we evaluated efficacy and mechanism of action of Deguelin in triple negative breast cancer cell lines. METHODS/FINDINGS: In vitro, Deguelin in a dose and time dependent manner inhibited the growth of MDA-MB-231, MDA-MB-468, BT-549 and BT-20 cells. Deguelin (2 or 4 mg/kg body weight, when injected intraperitoneally, reduced the in vivo tumor growth of MDA-MB-231 cells transplanted subcutaneously in athymic mice. Moreover it was nontoxic as evident from daily observations on mobility, food and water consumption and comparison of bodyweight and other visceral organ weights with those in control animals at the termination of the study. The western blot analyses and immunostaining studies indicated that the deguelin effects may be mediated through EGFR-PAKT/c-Met p-ERK and NF-κB by down regulating their downstream targets such as p-STAT3, c-Myc, Survivin. CONCLUSION/SIGNIFICANCE: These results suggest that Deguelin may have a significant therapeutic value for the treatment of TNBC patients.

  11. High levels of c-Met is associated with poor prognosis in glioblastoma

    DEFF Research Database (Denmark)

    Petterson, Stine Asferg; Dahlrot, Rikke Hedegaard; Hermansen, Simon Kjær;

    2015-01-01

    . Measurements of high c-Met intensity correlated with high WHO grade (p = 0.006) but no association with survival was observed in patients with WHO grade II (p = 0.09) or III (p = 0.17) tumors. High expression of c-Met was associated with shorter overall survival in patients with glioblastoma multiforme (p = 0.......03). However the prognostic effect of c-Met in glioblastomas was time-dependent and only observed in patients who survived more than 8.5 months, and not within the first 8.5 months after diagnosis. This was significant in multivariate analysis (HR 1.99, 95 % CI 1.29-3.08, p = 0.002) adjusted for treatment...... and the clinical variables age (HR 1.01, 95 % CI 0.99-1.03, p = 0.30), performance status (HR 1.34, 95 % CI 1.17-1.53, p glioblastomas....

  12. PRIMARY STUDY ON MECHANISM OF COLLAGEN SYNTHESIS INHIBITION IN CULTURED HUMAN FETAL HEPATOCYTES PRETREATED BY SALVIA MILTIORRHIZA BUNGE

    Institute of Scientific and Technical Information of China (English)

    赵英仁; 朱风群; 和水祥; 苌新明; 乔文

    2003-01-01

    Objective The effects of salvia miltiorrhiza bunge (SMB) on collagen synthesis in the human fetal hepatocytes culture were studied. Methods The collagen synthesis of hepatocytes were stimulated by the addition of carbon tetrachloride (CCl4) to the culture medium, the concentration of type procollagen (PC) in the culture medium and the hydroxyproline (Hyp) in hepatocytes were determined, as well as the activity of se-dependent glutathione peroxidase (Se-GSH-Px) and the concentration of malondiadehyde (MDA) in the culture medium. Results A significant decrease in PC, Hyp and MDA production, and the significant increase in Se-GSH-Px activity were observed in the cultures pretreated with 1 g L-1 SMB for 4 hours compared with the untreated cultures. Analysis of the Se-GSH-Px/MDA ratio in SMB pretreated group showed more marked increase compared to that of the untreated group (P<0.01). There was a significant negative correlation between the ratio of Se-GSH-Px/MDA and the concentration of PC in SMB pretreated group (r=-0.9017, P<0.01). Conclusion Our results indicate that SMB may suppress the collagen synthesis of cultured human fetal hepatocytes stimulated by CCl4, and its mechanism may be related to the increase in Se-GSH-Px/MDA ratio and the enhancement of hepatocytes antioxidation capability.

  13. E-cadherin and c-Met expression in actinic cheilits and lip squamous cell carcinoma

    Directory of Open Access Journals (Sweden)

    A Martínez

    2011-12-01

    Full Text Available Objective: The aim of this study was to assess epithelial expression of E-cadherin and c-Met in normal lip, in actinic cheilitis and lip squamous cell carcinoma. Study Design: Biopsies of normal lip vermillion (NL, n=18, actinic cheilitis (AC, n=37, and lip SCC (n=22 were processed for E-cadherin and c-Met immunodetection. Epithelial and tumor cell expression was scored for each sample considering staining intensity and percentage. Results: E-cadherin expression was significantly reduced in AC and lip SCC as compared to normal lip (P<0.05, with a significant reduction in lip SCC as compared to AC (P=0.003. Expression of c-Met was significantly higher in AC and lip SCC as compared to NL (P<0.05, with a significant increase in lip SCC as compared to AC (P<0.0001. Conclusion: The results showed that epithelial E-cadherin expression is reduced and c-Met expression is increased as lip carcinogenesis progresses, suggesting that these proteins may be useful markers of malignant transformation.

  14. Novel germline c-MET mutation in a family with hereditary papillary renal carcinoma

    DEFF Research Database (Denmark)

    Wadt, Karin; Gerdes, Anne-Marie; Hansen, Thomas V O;

    2012-01-01

    Hereditary papillary renal carcinoma (HPRC) is a highly penetrant hereditary renal cancer syndrome caused by germline missense mutations in the c-MET proto-oncogene. HPRC is clinically characterized by multiple bilateral papillary renal-cell carcinomas. Here we report a family with a novel missense...... mutation in c-MET. The original pathology report of four primary kidney cancers (1988-1997) revealed renal-cell carcinoma. A revised report described multiple adenomas and papillary renal-cell carcinomas with focal clear cells and a mixture of type 1 and type 2 pattern, emphasizing the importance...... of revised pathology examinations in possible hereditary renal-cell carcinomas especially when described before 1997....

  15. Structure Based Drug Design of Crizotinib (PF-02341066), a Potent and Selective Dual Inhibitor of Mesenchymal-Epithelial Transition Factor (c-MET) Kinase and Anaplastic Lymphoma Kinase (ALK)

    Energy Technology Data Exchange (ETDEWEB)

    Cui, J Jean; Tran-Dube,; #769; Michelle,; Shen, Hong; Nambu, Mitchell; Kung, Pei-Pei; Pairish, Mason; Jia, Lei; Meng, Jerry; Funk, Lee; Botrous, Iriny; McTigue, Michele; Grodsky, Neil; Ryan, Kevin; Padrique, Ellen; Alton, Gordon; Timofeevski, Sergei; Yamazaki, Shinji; Li, Qiuhua; Zou, Helen; Christensen, James; Mroczkowski, Barbara; Bender, Steve; Kania, Robert S; Edwards, Martin P [Pfizer

    2011-08-03

    Because of the critical roles of aberrant signaling in cancer, both c-MET and ALK receptor tyrosine kinases are attractive oncology targets for therapeutic intervention. The cocrystal structure of 3 (PHA-665752), bound to c-MET kinase domain, revealed a novel ATP site environment, which served as the target to guide parallel, multiattribute drug design. A novel 2-amino-5-aryl-3-benzyloxypyridine series was created to more effectively make the key interactions achieved with 3. In the novel series, the 2-aminopyridine core allowed a 3-benzyloxy group to reach into the same pocket as the 2,6-dichlorophenyl group of 3 via a more direct vector and thus with a better ligand efficiency (LE). Further optimization of the lead series generated the clinical candidate crizotinib (PF-02341066), which demonstrated potent in vitro and in vivo c-MET kinase and ALK inhibition, effective tumor growth inhibition, and good pharmaceutical properties.

  16. Inhibition of preS1-hepatocyte interaction by an array of recombinant human antibodies from naturally recovered individuals

    DEFF Research Database (Denmark)

    Sankhyan, Anurag; Sharma, Chandresh; Dutta, Durgashree;

    2016-01-01

    binding signature, interacting with different amino acids within the preS1-peptide region. Ability to prevent binding of the preS1 protein (N-terminus 60a.a.) to HepG2 cells stably expressing hNTCP (HepG2-hNTCP-C4 cells), the HBV receptor on human hepatocytes was taken as a surrogate marker...

  17. Hepatitis B Virus X Protein Sensitizes TRAIL-Induced Hepatocyte Apoptosis by Inhibiting the E3 Ubiquitin Ligase A20.

    Directory of Open Access Journals (Sweden)

    Hang Zhang

    Full Text Available Hepatitis B virus (HBV infection causes hepatocyte death and liver damage, which may eventually lead to cirrhosis and liver cancer. Hepatitis B virus X protein (HBx is a key antigen that is critically involved in HBV-associated liver diseases. However, the molecular basis for its pathogenesis, particularly in liver damage, has not been well defined. Herein, we report that HBx was able to enhance the susceptibility of hepatocytes to TNF-related apoptosis-inducing ligand (TRAIL-induced apoptosis. Increased sensitivity to TRAIL was associated with HBx-induced upregulation of miR-125a, which, in turn, suppressed the expression of its putative target gene, A20 E3 ligase. Importantly, we demonstrate that the defective expression of A20 impaired the K63-linked polyubiquitination of caspase-8, which reciprocally enhanced the activation of caspase-8, the recruitment of Fas-associated death domain (FADD, and the formation of death-inducing signaling complex (DISC, thereby promoting HBx-mediated apoptotic signaling. Accordingly, antagonizing miR-125a or ectopically expressing A20 in hepatocytes abolished the pro-apoptotic effect of HBx. Conversely, the overexpression of miR-125a or knockdown of A20 mimicked HBx to enhance TRAIL susceptibility in hepatocytes. Thus, we establish, for the first time, a miR-125a/A20-initiated and caspase-8-targeted mechanism by which HBx modulates apoptotic signaling and increases hepatic susceptibility to the damaging agent, which might provide novel insight into HBV-related liver pathology.

  18. Synthesis and biological evaluation of 4-phenoxy-6,7-disubstituted quinolines possessing semicarbazone scaffolds as selective c-Met inhibitors.

    Science.gov (United States)

    Qi, Baohui; Tao, Haiyan; Wu, Di; Bai, Jinying; Shi, Yandan; Gong, Ping

    2013-08-01

    Novel quinoline derivatives bearing acyclic semicarbazones were prepared and their chemical structures as well as the relative stereochemistry were confirmed. All the synthesized compounds were evaluated for their c-Met kinase inhibitory activity and their cytotoxicity against the cell lines HT-29, MKN-45, and MDA-MB-231 in vitro. Several potent compounds were further evaluated against A549 cells. Most compounds displayed moderate to excellent activity, and the structure-activity relationship studies identified the most promising compound 35 as a selective c-Met kinase inhibitor (IC50  = 4.3 nM). Compound 35 showed a 3.5- and 18.8-fold increase in cytotoxicity in vitro against HT-29 and A549 cells, respectively, compared to that of foretinib. Poor off-target effects of compound 35 were further confirmed by the antiproliferative activity against the c-Met inhibition less sensitive MDA-MB-231 cell line (IC50  = 0.77 µM).

  19. The afatinib resistance of in vivo generated H1975 lung cancer cell clones is mediated by SRC/ERBB3/c-KIT/c-MET compensatory survival signaling.

    Science.gov (United States)

    Booth, Laurence; Roberts, Jane L; Tavallai, Mehrad; Webb, Timothy; Leon, Daniel; Chen, Jesse; McGuire, William P; Poklepovic, Andrew; Dent, Paul

    2016-04-12

    We generated afatinib resistant clones of H1975 lung cancer cells by transient exposure of established tumors to the drug and collected the re-grown tumors. Afatinib resistant H1975 clones did not exhibit any additional mutations in proto-oncogenes when compared to control clones. Afatinib resistant H1975 tumor clones expressed less PTEN than control clones and in afatinib resistant clones this correlated with increased basal SRC Y416, ERBB3 Y1289, AKT T308 and mTOR S2448 phosphorylation, decreased expression of ERBB1, ERBB2 and ERBB3 and increased total expression of c-MET, c-KIT and PDGFRβ. Afatinib resistant clones were selectively killed by knock down of [ERBB3 + c-MET + c-KIT] but not by the individual or doublet knock down combinations. The combination of the ERBB1/2/4 inhibitor afatinib with the SRC family inhibitor dasatinib killed afatinib resistant H1975 cells in a greater than additive fashion; other drugs used in combination with dasatinib such as sunitinib, crizotinib and amufatinib were less effective. [Afatinib + dasatinib] treatment profoundly inactivated ERBB3, AKT and mTOR in the H1975 afatinib resistant clones and increased ATG13 S318 phosphorylation. Knock down of ATG13, Beclin1 or eIF2α strong suppressed killing by [ERBB3 + c-MET + c-KIT] knock down, but were only modestly protective against [afatinib + dasatinib] lethality. Thus afatinib resistant H1975 NSCLC cells rely on ERBB1- and SRC-dependent hyper-activation of residual ERBB3 and elevated signaling, due to elevated protein expression, from wild type c-MET and c-KIT to remain alive. Inhibition of ERBB3 signaling via both blockade of SRC and ERBB1 results in tumor cell death.

  20. Indolo[3,2-b]carbazole inhibits gap junctional intercellular communication in rat primary hepatocytes and acts as a potential tumor promoter

    DEFF Research Database (Denmark)

    Herrmann, Susan; Seidelin, Michel; Bisgaard, Hanne Cathrine

    2002-01-01

    Indole-3-carbinol (I3C) is a naturally occurring substance that shows anti-carcinogenic properties in animal models. Besides its clear anti-carcinogenic effects, some studies indicate that I3C may sometimes act as a tumor promoter. Indolo[3,2-b]carbazole (ICZ), which is formed in the acidic...... environment of the stomach after intake of I3C, has a similar structure to, and shares biological effects with, the well-known tumor promoter 2,3,7,8-tetrachlorodibenzo-pdioxin (TCDD). Therefore, we hypothesized that ICZ could be responsible for the potential tumor-promoting activity of I3C. The aim...... of the present study was to investigate the effect of ICZ on gap junctional intercellular communication (GJIC) in primary cultured rat hepatocytes co-cultured with the rat liver epithelial cell line WB-F344. Indolo[3,2-b]carbazole inhibited GJIC in the rat hepatocytes in a dose- and time-dependent manner...

  1. Efficient Recombinase-Mediated Cassette Exchange in hPSCs to Study the Hepatocyte Lineage Reveals AAVS1 Locus-Mediated Transgene Inhibition

    Directory of Open Access Journals (Sweden)

    Laura Ordovás

    2015-11-01

    Full Text Available Tools for rapid and efficient transgenesis in “safe harbor” loci in an isogenic context remain important to exploit the possibilities of human pluripotent stem cells (hPSCs. We created hPSC master cell lines suitable for FLPe recombinase-mediated cassette exchange (RMCE in the AAVS1 locus that allow generation of transgenic lines within 15 days with 100% efficiency and without random integrations. Using RMCE, we successfully incorporated several transgenes useful for lineage identification, cell toxicity studies, and gene overexpression to study the hepatocyte lineage. However, we observed unexpected and variable transgene expression inhibition in vitro, due to DNA methylation and other unknown mechanisms, both in undifferentiated hESC and differentiating hepatocytes. Therefore, the AAVS1 locus cannot be considered a universally safe harbor locus for reliable transgene expression in vitro, and using it for transgenesis in hPSC will require careful assessment of the function of individual transgenes.

  2. Expressions of estrogen receptor subtypes and c-met proto-oncogene in endometrial carcinoma and their correlation

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Objective To investigate the expressions of estrogen receptor(ER)subtypes and c-met proto-oncogene in human endometrial carcinomas and to assess the clinical significance of ER and c-met in this carcinoma.Methods Reverse transcription PCR(RT-PCR)was used to detect the expressions of ERα,ERβ and c-met proto-oncogene mRNA in 30 samples of endometrial carcinoma and 11 samples of normal endometrium.Results The expression of ERα in endometrial carcinoma(0.70±0.40)was significantly reduced in comparison to that i...

  3. Inhibition of fatty acid synthesis in rat hepatocytes by exogenous polyunsaturated fatty acids is caused by lipid peroxidation

    DEFF Research Database (Denmark)

    Mikkelsen, L.; Hansen, Harald S.; Grunnet, N.

    1993-01-01

    by the peroxidized PUFA. Arachidonic acid and eicosapentaenoic acid showed a dose- and time-dependent cytotoxicity. Two other antioxidants: 50 µM a-tocopherol acid succinate and 1 µM N,N'-diphenyl-1,4-phenylenediamine, both proved more efficient than a-tocopherol phosphate. There was a significant correlation......Rat hepatocyte long-term cultures were utilized to investigate the impact of different polyunsaturated fatty acids (PUFA) on the insulin-induced de novo fatty acid synthesis in vitro. The addition of 0.5 mM albumin-complexed oleic, linoleic, columbinic, arachidonic, eicosapentaenoic...... or docosahexaenoic acid resulted in a marked suppression of fatty acid synthesis. By evaluation of cell viability (determined as the leakage of lactate dehydrogenase (LDH)) it turned our, that the antioxidant used (50 µM a-tocopherol phosphate) had a low antioxidant activity, resulting in cytotoxic effects...

  4. Research Progress of HGF/c-MET Inhibitor in the Treatment 
of Non-small Cell Lung Cancer

    Directory of Open Access Journals (Sweden)

    Tao JIANG

    2015-04-01

    Full Text Available Molecular targeted therapy has become more and more important in the treatment of non-small cell lung cancer (NSCLC. HGF/c-MET plays the pivotal role in the growth, development and tolerance to epidermal growth factor receptor tyrosine kinase inhibitor of NSCLC. Moreover it has become another heat point in the molecular targeted therapy of NSCLC. c-MET amplification or high expression was deemed to another significant gene modification beyond EGFR and ALK. In the preclinical studies, HGF/c-MET inhibitors have showed the promising anti-tumor effect. Recently, some phase II/III clinical trials have proved that these inhibitors could improve the survival of patients with NSCLC. Hence we performed this review to elaborate the research progress of c-MET inhibitor in the treatment of NSCLC.

  5. Fullerene inhibits benzo(a)pyrene Efflux from Cyprinus carpio hepatocytes by affecting cell membrane fluidity and P-glycoprotein expression.

    Science.gov (United States)

    Chen, Qiqing; Hu, Xialin; Wang, Rui; Yuan, Jin; Yin, Daqiang

    2016-05-01

    P-Glycoprotein (P-gp) can protect cells by pumping out toxic compounds, and has been found widely expressed in fish tissues. Here, we illustrate the P-gp efflux ability for benzo(a)pyrene (BaP) in the hepatocytes of common carp (Cyprinus carpio) after exposing to fullerene aqueous suspension (nC60). The results revealed that nC60 increased the membrane fluidity by decreasing the ratio of saturated to unsaturated fatty acids, and increased the cholesterol contents. These findings, combined with 10-38% and 70-75% down-regulation of P-gp mRNA and protein respectively, suggested that nC60 caused inhibition on P-gp efflux transport system. Therefore, we further investigated the cellular efflux ability for BaP. Results showed unequivocally that nC60 is a potent P-gp inhibitor. The retaining BaP amounts after efflux were elevated by 1.7-2.8 fold during the 10 day exposure. Meanwhile, 5mg/L humic acid (one of the important fractions of natural organic matter, which is ubiquitous in aquatic environment) alleviated the nC60 damage to hepatocytes in terms of oxidative damage, cholesterol increment, and P-gp content reduction; and finally attenuated the suppressed P-gp efflux ability. Collectively, this study provides the first evidence of nC60 toxicity to P-gp functionality in fish and illustrates the possible mechanism of the suppressed P-gp efflux ability for BaP.

  6. Molecular modeling studies and synthesis of novel quinoxaline derivatives with potential anticancer activity as inhibitors of c-Met kinase.

    Science.gov (United States)

    Abbas, Hebat-Allah S; Al-Marhabi, Aisha R; Eissa, Sally I; Ammar, Yousry A

    2015-10-15

    In an effort to develop potent anti-cancer agents, we have synthesized some substituted quinoxaline derivatives. Reaction of 6-bromo-3-methylquinoxalin-2(1H)-one 1 with aromatic aldehydes furnished the styryl derivatives 2a-e. Alkylation of 1 with ethyl chloroacetate produced the N-alkyl derivatives 3. Hydrazinolysis of the ester derivative 3 with hydrazine hydrate afforded the hydrazide derivative 4. In addition, chlorination of 1 with phosphorus oxychloride afforded the 2-chloro derivative 5 which was used as a key intermediate for the synthesis of substituted quinoxaline derivatives 6-8, N-pyrazole derivative 9, tetrazolo[1,5-a]quinoxaline derivative 10 and Schiff base derivatives 13, 15 via reaction with several nucleophiles reagents. Docking methodologies were used to predict their binding conformation to explain the differences of their tested biological activities. All the tested compounds were screened in vitro for their cytotoxic effect on three tumor cell lines. Some new quinoxaline derivatives were studied as inhibitors of c-Met kinase, a receptor associated with high tumor grade and poor prognosis in a number of human cancers. Compounds 2e, 4, 7a, 12a, 12b and 13 showed the highest binding affinity with CDOCKER energy score, while showed the lowest IC50 values against three types of cancer cell lines. It is worth to mention that, compounds 2e, 7a, 12b and 13 showed comparable inhibition activity to the reference drug, while compounds 4 and 12a showed a more potent inhibition activity than Doxorubicin.

  7. Hepatocyte growth factor in renal failure: promise and reality.

    Science.gov (United States)

    Vargas, G A; Hoeflich, A; Jehle, P M

    2000-04-01

    Can science discover some secrets of Greek mythology? In the case of Prometheus, we can now suppose that his amazing hepatic regeneration was caused by a peptide growth factor called hepatocyte growth factor (HGF). Increasing evidence indicates that HGF acts as a multifunctional cytokine on different cell types. This review addresses the molecular mechanisms that are responsible for the pleiotropic effects of HGF. HGF binds with high affinity to its specific tyrosine kinase receptor c-met, thereby stimulating not only cell proliferation and differentiation, but also cell migration and tumorigenesis. The three fundamental principles of medicine-prevention, diagnosis, and therapy-may be benefited by the rational use of HGF. In renal tubular cells, HGF induces mitogenic and morphogenetic responses. In animal models of toxic or ischemic acute renal failure, HGF acts in a renotropic and nephroprotective manner. HGF expression is rapidly up-regulated in the remnant kidney of nephrectomized rats, inducing compensatory growth. In a mouse model of chronic renal disease, HGF inhibits the progression of tubulointerstitial fibrosis and kidney dysfunction. Increased HGF mRNA transcripts were detected in mesenchymal and tubular epithelial cells of rejecting kidney. In transplanted patients, elevated HGF levels may indicate renal rejection. When HGF is considered as a therapeutic agent in human medicine, for example, to stimulate kidney regeneration after acute injury, strategies need to be developed to stimulate cell regeneration and differentiation without an induction of tumorigenesis.

  8. Mecp2-mediated Epigenetic Silencing of miR-137 Contributes to Colorectal Adenoma-Carcinoma Sequence and Tumor Progression via Relieving the Suppression of c-Met

    Science.gov (United States)

    Chen, Tao; Cai, Shi-Lun; Li, Jian; Qi, Zhi-Peng; Li, Xu-Quan; Ye, Le-Chi; Xie, Xiao-Feng; Hou, Ying-Yong; Yao, Li-Qing; Xu, Mei-Dong; Zhou, Ping-Hong; Xu, Jian-Min; Zhong, Yun-Shi

    2017-01-01

    The molecular mechanisms underlying colorectal cancer (CRC) development remain elusive. In this study, we examined the miRNA and mRNA expressions in the adenoma-carcinoma sequence (ACS), a critical neoplastic progression in CRC development. We found that miR-137 was down-regulated in all adenoma and carcinoma tissues. Low miR-137 levels were correlated negatively with tumor progression and metastasis. Then we identified the inhibition effect of the miR-137 in CRC development, both in CRC cell lines and mouse models. MiR-137 was shown to control CRC cell proliferation, colony formation, migration and invasion and to control tumor growth and metastasis. We further confirmed the negative association between miR-137 and c-Met expression and thus validated this important oncogene as the target of miR-137 in CRC. In addition, we found a DNA methyl-CpG-binding protein, Mecp2, was up-regulated in ACS tissues via mRNA sequencing. Further experiment showed that miR-137 expression in CRC was subjected to epigenetic regulation mediated by Mecp2. We also confirmed c-Met expression can be up-regulated by silencing of miR-137 and suppressed by coexpression of Mecp2 and miR-137. These findings highlight the critical role of miR-137-c-Met nexus in CRC development and reveal Mecp2-regulated epigenetic silence causes the downregulation of miR-137 in colorectal adenoma and carcinoma. PMID:28291253

  9. Design, synthesis and biological evaluation of 1H-pyrrolo[2,3-b]pyridine and 1H-pyrazolo[3,4-b]pyridine derivatives as c-Met inhibitors.

    Science.gov (United States)

    Liu, Na; Wang, Yanfen; Huang, Gongchao; Ji, Conghui; Fan, Wei; Li, Haitao; Cheng, Ying; Tian, Hongqi

    2016-04-01

    Five novel 1H-pyrrolo[2,3-b]pyridine or 1H-pyrazolo[3,4-b]pyridine derivatives, with a methylene, sulfur, sulfoxide or cyclopropyl group as a linker, were designed, synthesized and biologically evaluated against c-Met and ALK. The development of these methods of compound synthesis may provide an important reference for the construction of novel 7-azaindole and 7-azaindazole derivatives with a single atom linker. The enzyme assay and cell assay in vitro showed that compound 9 displayed strong c-Met kinase inhibition with IC50 of 22.8nM, moderate ALK kinase inhibition, and strong cell inhibition with MKN-45 IC50 of 329nM and EBC-1 IC50 of 479nM. In order to find the better candidate compounds, compounds 8, 9 and 10 have been selected as tool compounds for further optimization.

  10. Glucagon and cAMP inhibit cholesterol 7alpha-hydroxylase (CYP7A1) gene expression in human hepatocytes: discordant regulation of bile acid synthesis and gluconeogenesis.

    Science.gov (United States)

    Song, Kwang-Hoon; Chiang, John Y L

    2006-01-01

    The gene encoding cholesterol 7alpha-hydroxylase (CYP7A1) is tightly regulated to control bile acid synthesis and maintain lipid homeostasis. Recent studies in mice suggest that bile acid synthesis is regulated by the fasted-to-fed cycle, and fasting induces CYP7A1 gene expression in parallel to the induction of peroxisome proliferators-activated receptor gamma co-activator 1alpha (PGC-1alpha) and phosphoenolpyruvate carboxykinase (PEPCK). How glucagon regulates CYP7A1 gene expression in the human liver is not clear. Here we show that glucagon and cyclic adenosine monophosphate (cAMP) strongly repressed CYP7A1 mRNA expression in human primary hepatocytes. Reporter assays confirmed that cAMP and protein kinase A (PKA) inhibited human CYP7A1 gene transcription, in contrast to their stimulation of the PEPCK gene. Mutagenesis analysis identified a PKA-responsive region located within the previously identified HNF4alpha binding site in the human CYP7A1 promoter. Glucagon and cAMP increased HNF4alpha phosphorylation and reduced the amount of HNF4alpha present in CYP7A1 chromatin. Our findings suggest that glucagon inhibited CYP7A1 gene expression via PKA phosphorylation of HNF4alpha, which lost its ability to bind the CYP7A1 gene and resulted in inhibition of human CYP7A1 gene transcription. In conclusion, this study unveils a species difference in nutrient regulation of the human and mouse CYP7A1 gene and suggests a discordant regulation of bile acid synthesis and gluconeogenesis by glucagon in human livers during fasting.

  11. Assessment of competitive and mechanism-based inhibition by clarithromycin: use of domperidone as a CYP3A probe-drug substrate and various enzymatic sources including a new cell-based assay with freshly isolated human hepatocytes.

    Science.gov (United States)

    Michaud, Veronique; Turgeon, Jacques

    2010-04-01

    Clarithromycin is involved in a large number of clinically relevant drug-drug interactions. Discrepancies are observed between the magnitude of drug interactions predicted from in vitro competitive inhibition studies and changes observed clinically in the plasma levels of affected CYP3A substrates. The formation of metabolic-intermediate complexes has been proposed to explain these differences. The objectives of our study were: 1) to determine the competitive inhibition potency of clarithromycin on the metabolism of domperidone as a CYP3A probe drug using human recombinant CYP3A4 and CYP3A5 isoenzymes, human liver microsomes and cultured human hepatocytes; 2) to establish the modulatory role of cytochrome b5 on the competitive inhibition potency of clarithromycin; 3) to demonstrate the clarithromycin-induced formation of CYP450 metabolic-intermediate complexes in human liver microsomes; and 4) to determine the extent of CYP3A inhibition due to metabolic-intermediate complex formation using human liver microsomes and cultured human hepatocytes. At high concentrations (100 µM), clarithromycin had weak competitive inhibition potency towards CYP3A4 and CYP3A5. Inhibition potency was further decreased by the addition of cytochrome b5 (9-19%). Clarithromycin-induced metabolic-intermediate complexes were revealed by spectrophotometry analysis using human liver microsomes while time- and concentration-dependent mechanism-based inhibitions were quantified using isolated hepatocytes. These results indicate that mechanism-based but not competitive inhibition of CYP3As is the major underlying mechanism of drug-drug interactions observed clinically with clarithromycin. Drug interactions between clarithromycin and several CYP3A substrates are predicted to be insidious; the risk of severe adverse events should increase over time and persist for a few days after cessation of the drug.

  12. Protective Effect of Aframomum melegueta phenolics Against CCl4-Induced Rat Hepatocytes Damage; Role of Apoptosis and Pro-inflammatory Cytokines inhibition

    Science.gov (United States)

    El-Halawany, Ali M.; Dine, Riham Salah El; El Sayed, Nesrine S.; Hattori, Masao

    2014-01-01

    Aframomum melegueta is a commonly used African spice. Through a hepatoprotective bioassay-guided isolation, the chloroform fraction of A.melegueta seeds yielded one new diarylheptanoid named 3-(S)-acetyl-1-(4′-hydroxy-3′, 5′-di methoxyphenyl)-7-(3″,4″, 5″-trihydroxyphenyl)heptane (1), and two new hydroxyphenylalkanones, [8]-dehydrogingerdione (2) and [6]-dehydroparadol (3), in addition to six known compounds (4–9). The hepatoprotective effect of A. melegueta methanol extract, sub-fractions and isolated compounds was investigated using carbon tetrachloride (CCl4)-induced liver injury in a rat hepatocytes model. The methanol, chloroform extracts and compounds 1, 5, 8 and 9 of A. melegueta significantly inhibited the elevated serum alanine aminotransferase (ALT), thiobarbituric acid reactive substances (TBARS), tumor necrosis factor (TNFα), interleukin-1beta (Il-1β), caspase3 and 9 and enhanced the reduced liver glutathione (GSH) level caused by CCl4 intoxication. These results indicate that A.melegueta extracts, and isolated compounds play a protective role in CCl4 induced acute liver injury which might be due to elevated antioxidative defense potentials, suppressed inflammatory responses and apoptosis of liver tissue. PMID:25077538

  13. Discovery of quinazolin-4-amines bearing benzimidazole fragments as dual inhibitors of c-Met and VEGFR-2.

    Science.gov (United States)

    Shi, Lei; Wu, Ting-Ting; Wang, Zhi; Xue, Jia-Yu; Xu, Yun-Gen

    2014-09-01

    Both c-Met and VEGFR-2 are important targets for the treatment of cancers. In this study, a series of N-(2-phenyl-1H-benzo[d]imidazol-5-yl)quinazolin-4-amine derivatives were designed and identified as dual c-Met and VEGFR-2 inhibitors. Among these compounds bearing quinazoline and benzimidazole fragments, compound 7j exhibited the most potent inhibitory activity against c-Met and VEGFR-2 with IC50 of 0.05μM and 0.02μM, respectively. It also showed the highest anticancer activity against the tested cancer cell lines with IC50 of 1.5μM against MCF-7 and 8.7μM against Hep-G2. Docking simulation supported the initial pharmacophoric hypothesis and suggested a common mode of interaction at the ATP-binding site of c-Met and VEGFR-2, which demonstrates that compound 7j is a potential agent for cancer therapy deserving further researching.

  14. Immunohistochemical expressions of fatty acid synthase and phosphorylated c-Met in thyroid carcinomas of follicular origin.

    Science.gov (United States)

    Liu, Jing; Brown, Robert E

    2011-01-01

    Thyroid carcinoma is the most common endocrine malignancy and the first cause of death among endocrine cancers. Fatty acid synthase (FASN) and c-Met are overexpressed in many types of human cancers. Recent studies have suggested a functional interaction between FASN and c-Met. However, their roles in thyroid carcinomas have not been fully investigated. In this study, we evaluated the expressions of FASN and phosphorylated (p)-c-Met by using immunohistochemistry in thyroid carcinomas of follicular origin, from 32 patients. The adjacent non-neoplastic thyroid tissue was also evaluated for comparison. Immunoreactive intensity and extensiveness were semi-quantified. The overexpression of FASN was observed in a subset of papillary thyroid carcinomas (PTC) including the classical type and tall cell, follicular, trabecular/insular and diffuse sclerosing variants, a subset of follicular thyroid carcinomas (FTC), and the PTC and FTC components in anaplastic thyroid carcinomas (ATC). No overexpression was observed in the ATCs per se and the columnar cell, solid, and cribriform variants of PTCs. All Hürthle cell variant FTCs and non-neoplastic Hürthle cells demonstrated positive staining for FASN while the non-neoplastic follicular cells without Hürthle cell change were negative. An association in overexpression between FASN and p-c-Met was observed in the majority of carcinomas as well as in the non-neoplastic Hürthle cells. In conclusion, overexpressions of FASN and p-c-Met were observed in a subset of thyroid carcinomas of follicular origin, which may be of values for targeted therapy and predicting prognosis while the positive immunostaining for these immunomarkers may be nonspecific for Hürthle cell thyroid carcinomas.

  15. Schisandrin B inhibits cell growth and induces cellular apoptosis and autophagy in mouse hepatocytes and macrophages: implications for its hepatotoxicity.

    Science.gov (United States)

    Zhang, Yi; Zhou, Zhi-Wei; Jin, Hua; Hu, Chengbin; He, Zhi-Xu; Yu, Zhi-Ling; Ko, Kam-Ming; Yang, Tianxin; Zhang, Xueji; Pan, Si-Yuan; Zhou, Shu-Feng

    2015-01-01

    A number of drugs and herbal compounds have been documented to cause hepatoxicity. Schisandrin B (Sch B) is an active dibenzocyclooctadiene isolated from Schisandrae fructus, with a wide array of pharmacological activities. However, the potential hepatotoxicity of Sch B is a major safety concern, and the underlying mechanism for Sch B-induced liver toxic effects is not fully elucidated. In the present study, we aimed to investigate the liver toxic effects and the molecular mechanisms of Sch B in mouse liver and macrophage cells. The results have shown that Sch B exhibits potent grow inhibitory, proapoptotic, and proautophagic effects in AML-12 and RAW 264.7 cells. Sch B markedly arrested cells in G1 phase in both cell lines, accompanied by the down-regulation of cyclin dependent kinase 2 (CDK2) and cyclin D1 and up-regulation of p27 Kip1 and checkpoint kinase 1. Furthermore, Sch B markedly increased the apoptosis of AML-12 and RAW 264.7 cells with a decrease in the expression of B-cell lymphoma-extra-large and (Bcl-xl) B-cell lymphoma 2 (Bcl-2), but an increase in the expression of B-cell lymphoma 2-associated X protein (Bax). Sch B promoted the cleavage of caspase 3 and poly-adenosine diphosphate-ribose polymerase (PARP) in both cell lines. Additionally, Sch B significantly induced autophagy of AML-12 and RAW 264.7 cells. Sch B inhibited the activation of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway, as indicated by their altered phosphorylation, contributing to the proautophagic effect of Sch B. Taken together, our findings show that the inducing effects of Sch B on cell cycle arrest, apoptosis, and autophagy may contribute to its liver toxic effects, which might provide a clue for the investigation of the molecular toxic targets and underlying mechanisms for Sch B-induced hepatotoxicity in herbal consumers. More studies are warranted to fully delineate the underlying mechanisms, efficacy, and

  16. Ochratoxin A activates opposing c-MET/PI3K/Akt and MAPK/ERK 1-2 pathways in human proximal tubule HK-2 cells.

    Science.gov (United States)

    Özcan, Zeynep; Gül, Gizem; Yaman, Ibrahim

    2015-08-01

    Ochratoxin A (OTA) is a mycotoxin produced as a secondary metabolite by filamentous fungi, such as Aspergillus and Penicillium. Because OTA is a common contaminant of food and feeds, humans and animals are frequently exposed to OTA in daily life. It has been classified as a carcinogen in rodents and a possible carcinogen in humans. OTA has been shown to deregulate a variety of different signal transduction pathways in a cell type- and dosage-depending manner resulting in contrasting physiological effects, such as survival or cell death. While the ERK1-2 and JNK/SAPK MAPK pathways are major targets, knowledge about their role in OTA-mediated cell survival and death is fragmented. Similarly, the contribution of the PI3K/Akt pathway to the carcinogenic effect of OTA in proximal tubule cells has not been elucidated in detail. In this study, we demonstrated that OTA induced sustained activation of the PI3K/Akt and MEK/ERK1-2 signaling pathways in a dose- and time-dependent manner in HK-2 cells. Chemical inhibition of ERK1-2 activation or overexpression of dominant-negative and kinase-dead MEK1 leads to increased cell viability and decreased apoptosis in OTA-treated cells. Blockage of PI3K/Akt with Wortmannin aggravated the negative effect of OTA on cell viability and increased the levels of apoptosis. Moreover, we identified the c-MET proto-oncogene as an upstream receptor tyrosine kinase responsible for OTA-induced activation of PI3K/Akt signaling in HK-2 cells. Our data suggest that OTA may potentiate carcinogenesis by sustained activation of c-MET/PI3K/Akt signaling through suppression of apoptosis induced by MEK/ERK1-2 activation in damaged renal proximal tubule epithelial cells.

  17. c-Met Expression Is a Marker of Poor Prognosis in Patients With Locally Advanced Head and Neck Squamous Cell Carcinoma Treated With Chemoradiation

    Energy Technology Data Exchange (ETDEWEB)

    Baschnagel, Andrew M. [Department of Radiation Oncology, William Beaumont Hospital, Royal Oak, Michigan (United States); Williams, Lindsay [Department of Pathology, William Beaumont Hospital, Royal Oak, Michigan (United States); Hanna, Alaa; Chen, Peter Y.; Krauss, Daniel J. [Department of Radiation Oncology, William Beaumont Hospital, Royal Oak, Michigan (United States); Pruetz, Barbara L. [Beaumont BioBank, William Beaumont Hospital, Royal Oak, Michigan (United States); Akervall, Jan [Beaumont BioBank, William Beaumont Hospital, Royal Oak, Michigan (United States); Department of Otolaryngology, William Beaumont Hospital, Royal Oak, Michigan (United States); Wilson, George D., E-mail: George.Wilson@Beaumont.edu [Department of Radiation Oncology, William Beaumont Hospital, Royal Oak, Michigan (United States); Beaumont BioBank, William Beaumont Hospital, Royal Oak, Michigan (United States)

    2014-03-01

    Purpose: To examine the prognostic significance of c-Met expression in relation to p16 and epidermal growth factor receptor (EGFR) in patients with locally advanced head and neck squamous cell carcinoma (HNSCC) treated with definitive concurrent chemoradiation. Methods and Materials: Archival tissue from 107 HNSCC patients treated with chemoradiation was retrieved, and a tissue microarray was assembled. Immunohistochemical staining of c-Met, p16, and EGFR was performed. c-Met expression was correlated with p16, EGFR, clinical characteristics, and clinical endpoints including locoregional control (LRC), distant metastasis (DM), disease-free survival (DFS), and overall survival (OS). Results: Fifty-one percent of patients were positive for p16, and 53% were positive for EGFR. Both p16-negative (P≤.001) and EGFR-positive (P=.019) status predicted for worse DFS. Ninety-three percent of patients stained positive for c-Met. Patients were divided into low (0, 1, or 2+ intensity) or high (3+ intensity) c-Met expression. On univariate analysis, high c-Met expression predicted for worse LRC (hazard ratio [HR] 2.27; 95% CI, 1.08-4.77; P=.031), DM (HR 4.41; 95% CI, 1.56-12.45; P=.005), DFS (HR 3.00; 95% CI, 1.68-5.38; P<.001), and OS (HR 4.35; 95% CI, 2.13-8.88; P<.001). On multivariate analysis, after adjustment for site, T stage, smoking history, and EGFR status, only high c-Met expression (P=.011) and negative p16 status (P=.003) predicted for worse DFS. High c-Met expression was predictive of worse DFS in both EGFR-positive (P=.032) and -negative (P=.008) patients. In the p16-negative patients, those with high c-Met expression had worse DFS (P=.036) than did those with low c-Met expression. c-Met expression was not associated with any outcome in the p16-positive patients. Conclusions: c-Met is expressed in the majority of locally advanced HNSCC cases, and high c-Met expression predicts for worse clinical outcomes. High c-Met expression predicted for worse DFS in p16

  18. Concurrent Deletion of Cyclin E1 and Cyclin-Dependent Kinase 2 in Hepatocytes Inhibits DNA Replication and Liver Regeneration in Mice

    OpenAIRE

    Hu W; Nevzorova YA; Haas U; Moro N.; Sicinski P; Geng Y; Barbacid M; Trautwein C; Liedtke C.

    2014-01-01

    The liver has a strong regenerative capacity. After injury, quiescent hepatocytes can reenter the mitotic cell cycle to restore tissue homeostasis. This G0/G1-S cell-cycle transition of primed hepatocytes is regulated by complexes of cyclin-dependent kinase 2 (Cdk2) with E-type cyclins (CcnE1 or CcnE2). However, single genetic ablation of either E-cyclin or Cdk2 does not affect overall liver regeneration. Here, we systematically investigated the contribution of CcnE1, CcnE2, and Cdk2 for live...

  19. Matriptase is required for the active form of hepatocyte growth factor induced Met, focal adhesion kinase and protein kinase B activation on neural stem/progenitor cell motility.

    Science.gov (United States)

    Fang, Jung-Da; Lee, Sheau-Ling

    2014-07-01

    Hepatocyte growth factor (HGF) is a chemoattractant and inducer for neural stem/progenitor (NS/P) cell migration. Although the type II transmembrane serine protease, matriptase (MTP) is an activator of the latent HGF, MTP is indispensable on NS/P cell motility induced by the active form of HGF. This suggests that MTP's action on NS/P cell motility involves mechanisms other than proteolytic activation of HGF. In the present study, we investigate the role of MTP in HGF-stimulated signaling events. Using specific inhibitors of phosphatidylinositol-3-kinase (PI3K), protein kinase B (Akt) or focal adhesion kinase (FAK), we demonstrated that in NS/P cells HGF-activated c-Met induces PI3k-Akt signaling which then leads to FAK activation. This signaling pathway ultimately induces MMP2 expression and NS/P cell motility. Knocking down of MTP in NS/P cells with specific siRNA impaired HGF-stimulation of c-Met, Akt and FAK activation, blocked HGF-induced production of MMP2 and inhibited HGF-stimulated NS/P cell motility. MTP-knockdown NS/P cells cultured in the presence of recombinant protein of MTP protease domain or transfected with the full-length wild-type but not the protease-defected MTP restored HGF-responsive events in NS/P cells. In addition to functioning as HGF activator, our data revealed novel function of MTP on HGF-stimulated c-Met signaling activation.

  20. Studies on Platelet-Derived Growth Factor Beta-Receptor and Hepatocyte Growth Factor Receptor c-met in Paracrine Interactions in Human Breast Cancer

    Science.gov (United States)

    1996-09-01

    matrix. B.E. Elliott, R. Saulnier, B. Bhardwaj, R. Lall, D. Leopold, N. Rahimi, and L. Maxwell. UCLA Symposium on Breast and Prostate Cancer, Taos...adipocytes. N. Rahimi, R. Lall, R. Saulnier and B.E. Elliott. UCLA Symposium on Breast and Prostate Cancer, Taos, New Mexico, February, 1994. 34...seen throughout the stroma of eight nonmalig- taxis (16), and fibronectin matrix assembly (17) in connective nant breast tissues as well as of

  1. Establishment of Multiple Myeloma Cell lines with Hepatocyte growth factor (HGF) overexpression and knockdown

    OpenAIRE

    Qadir, Fouzia

    2013-01-01

    Multiple myeloma is the malignancy of plasma cells which causes 0.9 % of all cancer related deaths. These malignant plasma cells acquire chromosomal abnormalities and complex genetic instability. Hepatocyte growth factor (HGF) is a multifunctional cytokine promoting cell proliferation, survival, motility, scattering, differentiation and morphogenesis. HGF/c-MET pathway plays an important role in multiple myeloma pathogenesis and in extravasation and homing of myeloma cells to bone marrow micr...

  2. Overexpression of c-met in the early stage of pancreatic carcinogenesis; altered expression is not sufficient for progression from chronic pancreatitis to pancreatic cancer

    Institute of Scientific and Technical Information of China (English)

    Jun Yu; Eishi Nagai; Masao Tanaka; Kenoki Ohuchida; Kazuhiro Mizumoto; Nami Ishikawa; Yasuhiro Ogura; Daisuke Yamada; Takuya Egami; Hayato Fujita; Seiji Ohashi

    2006-01-01

    AIM: To investigate c-met expression during early pancreatic carcinogenesis.METHODS: We used 46 bulk tissues and 36 microdissected samples, including normal pancreas, chronic pancreatitis, and pancreatic cancer, for quantitative real time reverse transcription-polymerase chain reaction.RESULTS: In bulk tissue analyses, pancreatic cancer tissues expressed significantly higher levels of c-met than did chronic pancreatitis and normal pancreas tissues.c-met levels did not differ between chronic pancreatitis and normal pancreas tissues. In microdissection-based analyses, c-met was expressed at higher levels in microdissected pancreatic cancer cells and pancreatitisaffected epithelial cells than in normal ductal epithelial cells (both, P < 0.01). Interestingly, pancreatitis-affected epithelial cells expressed levels of c-met similar to those of pancreatic cancer cells.CONCLUSION: Overexpression of c-met occurs during the early stage of pancreatic carcinogenesis, and a single alteration of c-met expression is not sufficient for progression of chronic pancreatitis-affected epithelial cells to pancreatic cancer cells.

  3. MicroRNA-181b-5p, ETS1, and the c-Met pathway exacerbate the prognosis of pancreatic ductal adenocarcinoma after radiation therapy.

    Science.gov (United States)

    Tomihara, Hideo; Yamada, Daisaku; Eguchi, Hidetoshi; Iwagami, Yoshifumi; Noda, Takehiro; Asaoka, Tadafumi; Wada, Hiroshi; Kawamoto, Koichi; Gotoh, Kunihito; Takeda, Yutaka; Tanemura, Masahiro; Mori, Masaki; Doki, Yuichiro

    2017-03-01

    Preoperative chemoradiation therapy (CRT) for pancreatic ductal adenocarcinoma (PDAC) has emerged as a reasonable strategy that shows good prognostic impact. However, after preoperative CRT, resected specimens show remnant tumor cells, which indicate that some tumor cells had acquired or were selected for resistance to CRT. Recently, two oncological mechanisms, the EMT and the presence of CSCs, were reported to be associated with resistance in various cancers. Previous reports showed that HGF could induce EMT in PDAC cells; moreover, the HGF receptor, c-Met, was identified as a dominant pancreatic CSC marker. However, the clinical significance of c-Met expression remains unclear. So, we hypothesized that remnant PDAC tissue after CRT might harbor cells with high c-Met expression, and these cells may exacerbate patients' prognosis. In the immunohistochemical analysis, we showed that preoperative CRT was significantly associated with high c-Met expression; moreover, high c-Met expression was a significant marker of a dismal prognosis. Next, we investigated mechanisms of c-Met upregulation in PDAC cells. We established GEM-resistant and radioresistant PDAC cells to analyze the transcriptome involved in c-Met expression. The microarray data for the established radiation-resistant PDAC cells indicated miR-181b-5p downregulation, which targets ETS1, one of the transcription factors for c-Met, and it was shown that radiation exposure induced c-Met expression through ETS1 increase by the suppression of miR-181b-5p. These results suggested that targeting these mechanisms may promote the development of a novel multidisciplinary treatment strategy for improving preoperative CRT efficiency.

  4. Inhibitive effect of cremophor RH40 or tween 80-based self-microemulsiflying drug delivery system on cytochrome P450 3A enzymes in murine hepatocytes.

    Science.gov (United States)

    Rao, Zichao; Si, Luqin; Guan, Yanbin; Pan, Hongping; Qiu, Jun; Li, Gao

    2010-10-01

    This study examined the effect of self-microemulsiflying drug delivery system (SMEDDS) containing Cremophor RH40 or Tween 80 at various dilutions on cytochrome P450 3A (CYP3A) enzymes in rat hepatocytes, with midazolam serving as a CYP3A substrate. The particle size and zeta potential of microemulsions were evaluated upon dilution with aqueous medium. In vitro release was detected by a dialysis method in reverse. The effects of SMEDDS at different dilutions and surfactants at different concentrations on the metabolism of MDZ were investigated in murine hepatocytes. The cytotoxicity of SMEDDS at different dilutions was measured by LDH release and MTT technique. The effects of SMEDDS on the CYP3A enzymes activity were determined by Western blotting. Our results showed that dilution had less effect on the particle size and zeta potential in the range from 1:25 to 1:500. The MDZ was completely released in 10 h. A significant decrease in the formation of 1'-OH-MDZ in rat hepatocytes was observed after treatment with both SMEDDS at dilutions ranging from 1:50 to 1:250 and Cremophor RH 40 or Tween 80 at concentrations ranging from 0.1% to 1% (w/v), with no cytotoxicity observed. A significant decrease in CYP3A protein expression was observed in cells by Western blotting in the presence of either Cremophor RH40 or Tween 80-based SMEDDS at the dilutions ranging from 1:50 to 1:250. This study suggested that the excipient inhibitor-based formulation is a potential protective platform for decreasing metabolism of sensitive drugs that are CYP3A substrates.

  5. Inhibition of hepatocyte nuclear factor 1 and 4 alpha (HNF1α and HNF4α) as a mechanism of arsenic carcinogenesis.

    Science.gov (United States)

    Pastoret, Anna; Marcos, Ricard; Sampayo-Reyes, Adriana; Saucedo-Cardenas, Odila; Lozano-Garza, Gerardo H; Hernandez, Alba

    2013-06-01

    Inorganic arsenic (i-As) is a naturally occurring toxic metalloid affecting millions of people worldwide. It is known to be carcinogen, liver being a potential target, and related to the prevalence of diabetes in arseniasis-endemic areas. Hepatocyte nuclear factor 1 and 4 alpha (HNF1α and HNF4α) are key members of a transcriptional network essential for normal liver architecture. Changes in HNF1α and HNF4α expression are clearly associated with the development of liver malignancies and diabetes in humans. In this work, hepatic HepG2 cells and golden Syrian hamsters were exposed to sub-toxic, environmentally relevant doses of sodium arsenite (SA; up to 10 μM in vitro, 15 mg/L in vivo) in order to evaluate whether arsenic is able to compromise the expression of hepatocyte nuclear factors. Also, liver histopathological examination was carried out, and several markers of hepatocyte differentiation and glucose metabolism status were determined as a measure of i-As-induced effects. Results show a consistent down-regulation of HNF1α and HNF4α under a scenario of exposure where HepG2 cells (1) gained resistance to arsenic-induced toxicity/apoptosis, (2) attained loss of tissue-specific features (as shown by the observed down-regulation of ALDOB, PEPCK and CYP1A2, triggering of the epithelial-to-mesenchymal transition program and the hypersecretion of matrix metalloproteinase-2 and 9), (3) failed to maintain balanced expression of the "stemness" genes C-MYC, OCT3/4, LIN28 and NOTCH2 and (4) showed glucose metabolism impairment. We conclude that the i-As-induced down-regulation of HNF1α and HNF4α under chronic settings may play a central role in the features of disease and cancer observed both in vivo and in vitro.

  6. Glutamine inhibits CCl4 induced liver fibrosis in mice and TGF-β1 mediated epithelial-mesenchymal transition in mouse hepatocytes.

    Science.gov (United States)

    Shrestha, Nirajan; Chand, Lokendra; Han, Myung Kwan; Lee, Seung Ok; Kim, Chan Young; Jeong, Yeon Jun

    2016-07-01

    Glutamine, traditionally a non-essential amino acid, now has been considered as essential in serious illness and injury. It is a major precursor for glutathione synthesis. However, the anti-fibrotic effect of glutamine and its molecular mechanism in experimental liver fibrosis have not been explored. In the present study we aimed to examine the potential role of glutamine in carbon tetrachloride (CCl4) induced liver fibrosis and TGF-β1 mediated epithelial mesenchymal transition (EMT) and apoptosis in mouse hepatocytes. Liver fibrosis was induced by intraperitoneal injection of CCl4 three times a week for 10 weeks. Glutamine treatment effectively attenuated liver injury and oxidative stress. Collagen content was significantly decreased in liver sections of glutamine treated mice compared to CCl4 model mice. Furthermore, glutamine decreased expression level of α-SMA and TGF-β in liver tissue. Our in vitro study showed that TGF-β1 treatment in hepatocytes resulted in loss of E-cadherin and increased expression of mesenchymal markers and EMT related transcription factor. In addition, TGF-β1 increased the expression of apoptotic markers. However, glutamine interestingly suppressed TGF-β1 mediated EMT and apoptosis. In conclusion, our results suggest that glutamine ameliorates CCl4 induced liver fibrosis and suppresses TGF-β1 induced EMT progression and apoptosis.

  7. Gene signatures derived from a c-MET-driven liver cancer mouse model predict survival of patients with hepatocellular carcinoma.

    Directory of Open Access Journals (Sweden)

    Irena Ivanovska

    Full Text Available Biomarkers derived from gene expression profiling data may have a high false-positive rate and must be rigorously validated using independent clinical data sets, which are not always available. Although animal model systems could provide alternative data sets to formulate hypotheses and limit the number of signatures to be tested in clinical samples, the predictive power of such an approach is not yet proven. The present study aims to analyze the molecular signatures of liver cancer in a c-MET-transgenic mouse model and investigate its prognostic relevance to human hepatocellular carcinoma (HCC. Tissue samples were obtained from tumor (TU, adjacent non-tumor (AN and distant normal (DN liver in Tet-operator regulated (TRE human c-MET transgenic mice (n = 21 as well as from a Chinese cohort of 272 HBV- and 9 HCV-associated HCC patients. Whole genome microarray expression profiling was conducted in Affymetrix gene expression chips, and prognostic significances of gene expression signatures were evaluated across the two species. Our data revealed parallels between mouse and human liver tumors, including down-regulation of metabolic pathways and up-regulation of cell cycle processes. The mouse tumors were most similar to a subset of patient samples characterized by activation of the Wnt pathway, but distinctive in the p53 pathway signals. Of potential clinical utility, we identified a set of genes that were down regulated in both mouse tumors and human HCC having significant predictive power on overall and disease-free survival, which were highly enriched for metabolic functions. In conclusions, this study provides evidence that a disease model can serve as a possible platform for generating hypotheses to be tested in human tissues and highlights an efficient method for generating biomarker signatures before extensive clinical trials have been initiated.

  8. Relationship between pathological characteristics of prostate cancer and MACC1, c-Met, Apaf-1 as well as Caspase-9 expression in tumor tissue

    Institute of Scientific and Technical Information of China (English)

    Hang-Yu Ai; Xue-De Qiu

    2016-01-01

    Objective:To study the MACC1, c-Met, Apaf-1 and Caspase-9 expression in prostate cancer tissue and their relationship with the pathological characteristics of tumor.Methods:Prostate cancer and benign prostatic hyperplasia patients who received surgical treatment in our hospital from May 2015 to March 2016 were selected as the research subjects, prostate cancer tissue and benign prostatic hyperplasia tissue were collected during surgery to determine MACC1, c-Met, Apaf-1 and Caspase-9 expression, and serum specimens were collected to determine miR-let7i, -32, -128, -196a and -218 expression levels.Results: mRNA content of MACC1 and c-Met in prostate cancer tissue were significantly higher than those in benign prostatic hyperplasia tissue while mRNA content of Apaf-1 and Caspase-9 were significantly lower than those in benign prostatic hyperplasia tissue, and the higher the Gleason grading and the higher the Whitmore-Prout staging, the higher the mRNA content of MACC1 and c-Met in prostate cancer tissue and the lower the mRNA content of Apaf-1 and Caspase-9; serum miR-32, miR-128 and miR-196a expression levels in prostate cancer patients were significantly higher than those in patients with benign prostatic hyperplasia and negatively correlated with the mRNA content of Apaf-1 and Caspase-9, and the expression levels of miR-let7i and miR-218 were significantly lower than those in patients with benign prostatic hyperplasia and negatively correlated with MACC1 and c-Met.Conclusion: High MACC1 and c-Met expression and low Caspase-9 and Apaf-1 expression are related to the occurrence and progression of prostate cancer, and the MACC1, c-Met, Apaf-1 and Caspase-9 expression in prostate cancer tissue are regulated by miRNAs.

  9. Design and synthesis of novel benzo[d]oxazol-2(3H)-one derivatives bearing 7-substituted-4-enthoxyquinoline moieties as c-Met kinase inhibitors.

    Science.gov (United States)

    Lu, Dong; Shen, Aijun; Liu, Yang; Peng, Xia; Xing, Weiqiang; Ai, Jing; Geng, Meiyu; Hu, Youhong

    2016-06-10

    Analysis of the results of studies of docking 1 and 7a with c-Met kinase led to the identification of benzo[d]oxazol-2(3H)-one-quinolone derivatives as potential inhibitors of this enzyme. A molecular hybrid strategy, using a 4-ethoxy-7-substituted-quinoline core and a benzo[d]oxazol-2(3H)-one scaffold, was employed to design members of this family for study as inhibitors of the kinase and proliferation of EBC-1 cells. Most of the substances were found to display good to excellent c-Met kinase inhibitory activities. The results of a structure-activity relationship (SAR) study led to the discovery of benzo[d]oxazol-2(3H)-one-quinolone 13, which has IC50 values of 1 nM against c-Met kinase and 5 nM against proliferation of the EBC-1 cell line.

  10. Transcriptional activation of the Axl and PDGFR-α by c-Met through a ras- and Src-independent mechanism in human bladder cancer

    Directory of Open Access Journals (Sweden)

    Tseng Vincent S

    2011-04-01

    Full Text Available Abstract Background A cross-talk between different receptor tyrosine kinases (RTKs plays an important role in the pathogenesis of human cancers. Methods Both NIH-Met5 and T24-Met3 cell lines harboring an inducible human c-Met gene were established. C-Met-related RTKs were screened by RTK microarray analysis. The cross-talk of RTKs was demonstrated by Western blotting and confirmed by small interfering RNA (siRNA silencing, followed by elucidation of the underlying mechanism. The impact of this cross-talk on biological function was demonstrated by Trans-well migration assay. Finally, the potential clinical importance was examined in a cohort of 65 cases of locally advanced and metastatic bladder cancer patients. Results A positive association of Axl or platelet-derived growth factor receptor-alpha (PDGFR-α with c-Met expression was demonstrated at translational level, and confirmed by specific siRNA knock-down. The transactivation of c-Met on Axl or PDGFR-α in vitro was through a ras- and Src-independent activation of mitogen-activated protein kinase/extracellular signal-regulated kinase (MEK/ERK pathway. In human bladder cancer, co-expression of these RTKs was associated with poor patient survival (p p Conclusions In addition to c-Met, the cross-talk with Axl and/or PDGFR-α also contributes to the progression of human bladder cancer. Evaluation of Axl and PDGFR-α expression status may identify a subset of c-Met-positive bladder cancer patients who may require co-targeting therapy.

  11. Induction and inhibition of cytochrome P450 1A1 and ethoxyresorufin-O-deethylation activity by polybrominated diphenyl ethers (PBDEs) in cynomolgus monkey primary hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Peters, L.; Sanderson, J.T.; Berg, M. van den [Utrecht Univ. (Netherlands). Inst. for Risk Assessment Sciences; Bergman, A. [Stockholm Univ. (Sweden). Dept. of Environmental Chemistry

    2004-09-15

    Brominated flame retardants (BFRs) make up for 39% of the worldwide flame-retardants market. One groups of BFR, Polybrominated diphenylethers (PBDEs) are used as additive flameretardants in plastic materials, paints, and textile fabrics. Some PBDEs have been found to be lipophilic and persistent, and consequently bioaccumulate. Recently, levels of some PBDEs have been increasing in fish, wildlife, and in human tissue. The structural similarity of certain PBDE congeners to other polyhalogenated aromatic hydrocarbons such as polychlorinated biphenyls (PCBs) has raised concerns that these compounds might act as agonists for the aryl hydrocarbon receptor (AhR). If some of these PBDEs were to act as Ah receptor agonists, they would warrant inclusion in the toxic equivalence factor (TEF) concept. CYP1A1 is a cytochrome P450 (CYP) enzyme that is involved in phase 1 biotransformation of xenobiotics and endogenous compounds such as estrogens. Many CYP enzymes detoxify xenobiotics or bioactivate xenobiotics to reactive intermediates. Although CYP1A1 is expressed in all mammals, there are differences in expression levels among species and tissues. To study the possible dioxin-like effects of environmentally most relevant PBDEs (BDE47, 77, 99, 100, 153, 154, 183, 209), the Ah receptor-mediated induction CYP1A1 was studied in cynomolgus monkey (Macaca fascicularis) primary hepatocytes. CYP 1A1 is the major enzyme that catalyses the deethylation of 7-ethoxyresorufin to resorufin. This ethoxyresorufin-Odeethylation (EROD) activity was used as a marker for CYP1A1 activity.

  12. Effects of quercetin on hepatocyte stimulating factor production by mouse peritoneal macrophases

    Institute of Scientific and Technical Information of China (English)

    周斌; 张俊平; 刘宏; 殷明; 钱定华

    2003-01-01

    Objective: To study the effects of quercetin on hepatocyte stimulating factor production from mouse peritoneal macrophages. Methods: Hepatocyte stimulating factor was evaluated by the amount of fibrinogen synthesized in Hep3B cells. Interleukin-6 activity was measured by B9 cell proliferation methyl thiazolyl tetrazolium colorimetric method. Hep3B cell supernatant fibrinogen was quantitated with ELISA. Results: LPS induced the synthesis of hepatocyte stimulating factor in mouse peritoneal macrophages, and hepatocyte stimulating factor promotes the synthesis of fibrinogen from Hep3B cells. Quercetin(5 to 40 μmol/ L)inhibited the synthesis of hepatocyte stimulating factor stimulated by LPS. Quercetin(5 to 20 μmol/ L) inhibited release of interleukin-6 from mouse peritoneal macrophages induced by 0.5 g/ L fibrin fibrinogen degradation products. Conclusion: Quercetin inhibits the synthesis of hepatocyte stimulating factor in macrophages.

  13. 抑制脂筏对肝细胞生长因子受体介导的信号跨膜转导作用的影响%Effects of lipid rafts on signal transmembrane transduction mediated by c-Met

    Institute of Scientific and Technical Information of China (English)

    王蕾; 赵玉峰; 李亚丽; 徐跃飞; 夏泉; 马克里

    2008-01-01

    Objective To study the effects of lipid rafts on cell signal transmembrane transduction mediated by c-Met. Methods After HepG2Cells were treated with MβCD to disrupt the lipid rafts and were treated with artificial recombination hepatocyte growth factor to activate c-Met, the activities of PLCγ1/PKC, P13K/Akt and MAPK signaling pathways in HepG2 cells were analyzed using Western blot. Results (1) After disruption of lipid rafts with MβCD, phosphorylation of PLCγ1 decreased by 35% (P=0.022); the content of PLCγ in the cytoplasm increased by 1.75 fold (P=0.017); PLCγ1 conjugated with membrane decreased by 30% (P=0.037). (2) The content of PKB in the cytosol decreased by 38% (P=0.028), and the phosphorylation level of PKB conjugated with membrane decreased by 14% (P=0.041). At the same time, PDK translocation from cytosol to the plasma membrane and its activation were inhibited by treatment with MβCD. (3) Treatment with MβCD had no significant effect on ErK/MAPK, p38/MAPK and JNK/MAPK signaling pathways. Conclusion Disruption of lipid rafts with MβCD inhibits the activation of PLCγ1/PKC and PI3K/PKB signaling pathways by HGF/cMet, but has no effect on MAPK signaling pathway.%目的 探讨脂筏在肝细胞生长因子受体介导的信号跨膜转导中的作用.方法 采用甲基-β-环糊精(MβCD)处理HepG2细胞,以干扰脂筏的形成,然后加入人工重组肝细胞生长因子以活化其受体.采用Western blot技术及计算机扫描定量分析分别检测MβCD处理组和对照组细胞磷脂酶Cγ1(PLCγ1)/二脂酰甘油/蛋白激酶C信号通路、磷脂酰肌醇-3-激酶/磷脂酰肌醇依赖的蛋白激酶/蛋白激酶B信号通路和有丝分裂原激活的蛋白激酶(MAPK)信号通路活性的变化.结果 (1)用MβCD处理细胞后,细胞PLCγ1磷酸化程度降低,为对照组的65%(P=0.022);胞浆中PLCγ1含量增加,为对照组的1.75倍(P=0.017);膜结合的PLCγ1减少,为对照组的70%(P=0.037).(2)用MβCD处理细胞

  14. Design, Synthesis, and Biological Evaluation of 4-Phenoxyquinoline Derivatives Containing Benzo[d]thiazole-2-yl Urea as c-Met Kinase Inhibitors.

    Science.gov (United States)

    Lei, Hongrui; Hu, Gang; Wang, Yu; Han, Pei; Liu, Zijian; Zhao, Yanfang; Gong, Ping

    2016-08-01

    A series of novel 4-phenoxyquinoline derivatives containing the benzo[d]thiazole-2-yl urea moiety were synthesized and evaluated for their cytotoxicity against the HT-29, MKN-45, and H460 cell lines. The structures of the target compounds were confirmed by (1) H NMR and MS spectra. Most of them showed moderate to excellent potency against the three tested cell lines. Especially, compound 23 was identified a promising agent (c-Met IC50  = 17.6 nM), showing the most potent anticancer activities with IC50 values of 0.18, 0.06, and 0.01 µM against the HT-29, MKN-45, and H460 cell lines, respectively. The docking results of 23 with the c-Met kinase model 3LQ8 showed a specific binding mode between the ligand and the target protein.

  15. Lysophosphatidic acid transactivates both c-Met and epidermal growth factor receptor, and induces cyclooxygenase-2 expression in human colon cancer LoVo cells

    Institute of Scientific and Technical Information of China (English)

    Dai Shida; Joji Kitayama; Hironori Yamaguchi; Hiroharu Yamashita; Ken Mori; Toshiaki Watanabe; Hirokazu Nagawa

    2005-01-01

    AIM: To examine whether lysophosphatidic acid (LPA)induces phosphorylation of c-Met and epidermal growth factor receptor (EGFR), both of which have been proposed as prognostic markers of colorectal cancer, and whether LPA induces cyclooxygenase-2 (COX-2) expression in human colon cancer cells.METHODS: Using a human colon cancer cell line, LoVo cells, we performed immunoprecipitation analysis,followed by Western blot analysis. We also examined whether LPA induced COX-2 expression, by Western blot analysis.RESULTS: Immunoprecipitation analysis revealed that 10 μmol/L LPA induced tyrosine phosphorylation of c-Met and EGFR in LoVo cells within a few minutes. We found that c-Met tyrosine phosphorylation induced by LPA was not attenuated by pertussis toxin or a matrix metalloproteinase inhibitor, in marked contrast to the results for EGFR. In addition, 0.2-40 μmol/L LPA induced COX-2 expression in a dose-dependent manner.CONCLUSION: Our results suggest that LPA acts upstream of various receptor tyrosine kinases (RTKs) and COX-2,and thus may act as a potent stimulator of colorectal cancer.

  16. Hepatocyte differentiation of mesenchymalstemcells

    Institute of Scientific and Technical Information of China (English)

    Xu-Bo Wu; Ran Tao

    2012-01-01

    BACKGROUND: Liver cell transplantation and bioartiifcial liver may provide metabolic support of liver function temporary and are prospective treatments for patients with liver failure. Mesenchymal stem cells (MSCs) are expected to be an ideal cell source for transplantation or liver tissue engineering, however the hepatic differentiation of MSCs is still insufifcient for clinical application. DATA  SOURCES: A PubMed search on "mesenchymal stem cells","liver cell"and"hepatocyte differentiation"was performed on the topic, and the relevant articles published in the past ten years were reviewed. RESULTS:Hepatocyte-like cells differentiated from MSCs are a promising cell source for liver regeneration or tissue engineering. Although it is still a matter of debate as to whether MSC-derived hepatocytes may efifciently repopulate a host liver to provide adequate functional substitution, the majority of animal studies support that MSCs can become key players in liver-directed regenerative medicine. However the clinical application of human stem cells in the treatment of liver diseases is still in its infancy. CONCLUSIONS: Future studies are required to improve the efifcacy and consistency of hepatic differentiation from MSCs. It is necessary to better understand the mechanism to achieve transdifferentiation with high efifciency. More clinical trials are warranted to prove their efifcacy in the management of patients with liver failure.

  17. Deregulation of ARID1A, CDH1, cMET and PIK3CA and target-related microRNA expression in gastric cancer

    Science.gov (United States)

    Ibarrola-Villava, Maider; Llorca-Cardeñosa, Marta J.; Tarazona, Noelia; Mongort, Cristina; Fleitas, Tania; Perez-Fidalgo, José Alejandro; Roselló, Susana; Navarro, Samuel; Ribas, Gloria; Cervantes, Andrés

    2015-01-01

    Genetic and epigenetic alterations play an important role in gastric cancer (GC) pathogenesis. Aberrations of the phosphatidylinositol-3-kinase signaling pathway are well described. However, emerging genes have been described such as, the chromatin remodeling gene ARID1A. Our aim was to determine the expression levels of four GC-related genes, ARID1A, CDH1, cMET and PIK3CA, and 14 target-related microRNAs (miRNAs). We compared mRNA and miRNA expression levels among 66 gastric tumor and normal adjacent mucosa samples using quantitative real-time reverse transcription PCR. Moreover, ARID1A, cMET and PIK3CA protein levels were assessed by immunohistochemistry (IHC). Finally, gene and miRNAs associations with clinical characteristics and outcome were also evaluated. An increased cMET and PIK3CA mRNA expression was found in 78.0% (P = 2.20 × 10−5) and 73.8% (P = 1.00 × 10−3) of the tumors, respectively. Moreover, IHC revealed that cMET and PIK3CA expression was positive in 63.6% and 87.8% of the tumors, respectively. Six miRNAs had significantly different expression between paired-samples, finding five up-regulated [miR-223-3p (P = 1.65 × 10−6), miR-19a-3p (P = 1.23 × 10−4), miR-128-3p (P = 3.49 × 10−4), miR-130b-3p (P = 1.00 × 10−3) and miR-34a-5p (P = 4.00 × 10−3)] and one down-regulated [miR-124-3p (P = 0.03)]. Our data suggest that cMET, PIK3CA and target-related miRNAs play an important role in GC and may serve as potential targets for therapy. PMID:26334097

  18. Phase II study evaluating 2 dosing schedules of oral foretinib (GSK1363089, cMET/VEGFR2 inhibitor, in patients with metastatic gastric cancer.

    Directory of Open Access Journals (Sweden)

    Manish A Shah

    Full Text Available PURPOSE: The receptors for hepatocyte and vascular endothelial cell growth factors (MET and VEGFR2, respectively are critical oncogenic mediators in gastric adenocarcinoma. The purpose is to examine the safety and efficacy of foretinib, an oral multikinase inhibitor targeting MET, RON, AXL, TIE-2, and VEGFR2 receptors, for the treatment of metastatic gastric adenocarcinoma. PATIENTS AND METHODS: Foretinib safety and tolerability, and objective response rate (ORR were evaluated in patients using intermittent (240 mg/day, for 5 days every 2 weeks or daily (80 mg/day dosing schedules. Thirty evaluable patients were required to achieve alpha = 0.10 and beta = 0.2 to test the alternative hypothesis that single-agent foretinib would result in an ORR of ≥ 25%. Up to 10 additional patients could be enrolled to ensure at least eight with MET amplification. Correlative studies included tumor MET amplification, MET signaling, pharmacokinetics and plasma biomarkers of foretinib activity. RESULTS: From March 2007 until October 2009, 74 patients were enrolled; 74% male; median age, 61 years (range, 25-88; 93% had received prior therapy. Best response was stable disease (SD in 10 (23% patients receiving intermittent dosing and five (20% receiving daily dosing; SD duration was 1.9-7.2 months (median 3.2 months. Of 67 patients with tumor samples, 3 had MET amplification, one of whom had SD. Treatment-related adverse events occurred in 91% of patients. Rates of hypertension (35% vs. 15% and elevated aspartate aminotransferase (23% vs. 8% were higher with intermittent dosing. In both patients with high baseline tumor phospho-MET (pMET, the pMET:total MET protein ratio decreased with foretinib treatment. CONCLUSION: These results indicate that few gastric carcinomas are driven solely by MET and VEGFR2, and underscore the diverse molecular oncogenesis of this disease. Despite evidence of MET inhibition by foretinib, single-agent foretinib lacked efficacy in

  19. Schisandrin B inhibits cell growth and induces cellular apoptosis and autophagy in mouse hepatocytes and macrophages: implications for its hepatotoxicity

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    Zhang Y

    2015-04-01

    Kip1 and checkpoint kinase 1. Furthermore, Sch B markedly increased the apoptosis of AML-12 and RAW 264.7 cells with a decrease in the expression of B-cell lymphoma-extra-large and (Bcl-xl B-cell lymphoma 2 (Bcl-2, but an increase in the expression of B-cell lymphoma 2-associated X protein (Bax. Sch B promoted the cleavage of caspase 3 and poly-adenosine diphosphate-ribose polymerase (PARP in both cell lines. Additionally, Sch B significantly induced autophagy of AML-12 and RAW 264.7 cells. Sch B inhibited the activation of phosphatidylinositol 3-kinase (PI3K/protein kinase B (Akt/mammalian target of rapamycin (mTOR signaling pathway, as indicated by their altered phosphorylation, contributing to the proautophagic effect of Sch B. Taken together, our findings show that the inducing effects of Sch B on cell cycle arrest, apoptosis, and autophagy may contribute to its liver toxic effects, which might provide a clue for the investigation of the molecular toxic targets and underlying mechanisms for Sch B-induced hepatotoxicity in herbal consumers. More studies are warranted to fully delineate the underlying mechanisms, efficacy, and safety of Sch B for clinical use.Keywords: herbal medicine, liver toxicity, mTOR, Bcl-2, AML-12 cell, RAW 264.7 cell

  20. Correlation of Epstein-Barr virus and its encoded proteins with Helicobacter pylori and expression of c-met and c-myc in gastric carcinoma

    Institute of Scientific and Technical Information of China (English)

    Bing Luo; Yun Wang; Xiao-Feng Wang; Yu Gao; Bao-Hua Huang; Peng Zhao

    2006-01-01

    AIM: To investigate the interrelationship of Epstein-Barr virus (EBV) and EBV- encoded proteins with Helicobacter pylori (H pylori) infection and the expression of c-met and c-myc oncogene proteins in gastric carcinoma, and to explore their role in gastric carcinogenesis.METHODS: One hundred and eighty-five gastric carcinoma tissues were detected by polymerase chain reaction (PCR)-Southern blot for EBV genome and in situ hybridization (ISH) for EBV-encoded small RNA 1 (EBER1). Gastric carcinoma with positive EBER1 signals was confirmed EBV-associated gastric carcinoma (EBVaGC). The status of H pylori infection in 185 gastric carcinomas was assessed by rapid urease test and PCR.The samples with positive PCR and urease test were defined as H pylori infection. The expression of c-met and c-myc oncogene proteins in tissues of EBVaGC and matched EBV-negative gastric carcinoma (EBVnGC) were examined by immunohistochemistry. RT-PCR and Southern hybridization were used to detect the expression of nuclear antigens (EBNAs) 1 and 2, latent membrane protein (LMP) 1, early genes BARF1 and BHRF1 in EBVaGC cases.RESULTS: The positive rate of H pylori and EBV in 185 gastric carcinomas was 59.45% (110/L85) and 7.03% (13/185) respectively. No difference was found in sex, age, pathological differentiation, clinical stages and lymph node metastasis between H pylori-positive and H pylori-negative gastric carcinomas. However, the positive rate of H pylori infection in the antrum gastric carcinomas was higher than that of cardia and body gastric carcinomas. In our series, age, pathological differentiation, clinical stages, lymph node metastasis and location of cancer were not different between EBVnGC and EBVaGC, while the positive rate of EBV in male patients was significantly higher than that of female patients. The positivity of Hpyloriin EBV-associated and EBV-negative gastric carcinomas was 46.15% (6/13) and 81.40%(104/172) respectively. There was no significant correlation between

  1. Culture of cryopreserved rat hepatocyte

    Institute of Scientific and Technical Information of China (English)

    Haitao Yin; Gaojun Teng; Lifeng Wang; Baorui Liu; Xiaoping Qian

    2006-01-01

    Objective: To study the method of cryopreserving rat hepatocytes and double collagen gel culture measurement after its cryopreservation. Methods: Rat hepatocytes, isolated by two-step perfusion with collagenase using an extra corporeal perfusion apparatus, were cryopreserved in double collagen gel with culture medium added by epidermal growth factor(EGF).The expression of cell function and cellular morphology were examined during culture. Results: The hepatocytes cryopreserved in double collagen gel concluding EGF showed good morphology and biological characteristics. After thawing, the MTT metabolism and protein synthesis of hepatocytes in sandwich ± EGF groups were better than those in control group. And the morphology and function of hepatocytes in sandwich group was better than that in EGF group(P < 0.05). Conclusion: Double collagen gel culture can keep hepatocyte's activities. Thawed hepatocytes can be cultivated with collagenous matrix, which provides an environment that more closely resembles that in vivo and maintain the expression of certain liver-specific function of hepatocytes.

  2. Bile acid formation in primary human hepatocytes

    Institute of Scientific and Technical Information of China (English)

    Curt Einarsson; Ewa Ellis; Anna Abrahamsson; Bo-G6ran Ericzon; Ingemar Bj rkhem; Magnus Axelson

    2000-01-01

    AIM To evaluate a culture system for bile acid formation in primary human hepatocytes in comparison with HepG2 cells. METHODS Hepatocytes were isolated from normal human liver tissue and were cultured in serum-free William's E medium. The medium was collected and renewed every 24 h. Bile acids and their precursors in media were finally analysed by gas chromatography-mass spectrometry. RESULTS Cholic acid ( CA ) andchenodeoxycholic acid (CDCA) conjugated with glycine or taurine accounted for 70% and 25% of total steroids. A third of CDCA was also conjugated with sulphuric acid. Dexamathasone and thyroid hormorm alone or in combination did not significantly effect bile acid formation. The addition of cyclosporin A (10 μmol/L) inhibited the synthesis of CA and CDCA by about 13% and 30%, respectively. CONCLUSION Isolated human hepatocytes in primary culture behave as in the intact liver by converting cholesterol to conjugated CA and CDCA. This is in contrast to cultured HepG2 cells, which release large amounts of bile acid precursors and unconjugated bile acids into the medium.

  3. Bile acid formation in primary human hepatocytes

    Institute of Scientific and Technical Information of China (English)

    Curt Einarsson; Ewa Ellis; Anna Abrahamsson; Bo-G ran Ericzon; Ingemar Bj rkhem; Magnus Axelson

    2000-01-01

    AIM To evaluate a system for bile acid formation in human hepatocytes in comparison with HepG2 cells.METHODS Hepatocytes were isolated from normal human liver tissue and were cultured in serum-freeWilliam's E medium. The medium was collected and renewed every 24 h. Bile acids and their precursors inmedia were finally analysed by gas chromatography-mass spectrometry.RESULTS Cholic acid (CA) and chenodeoxycholic acid (CDCA) conjugated with glycine or taurineaccounted for 70% and 25% of total steroids. One third of CDCA was also conjugated with sulphuric acid.Dexamethasone and thyroid hormone alone or in combination did not significantly affect bile acid formation.The addition of cyclosporin A (10 tm) inhibited the synthesis of CA and CDCA by about 13% and 30%,respectively.CONCLUSION Isolated human hepatocytes in primary culture behave as in the intact liver by convertingalmost quantitatively cholesterol to conjugated CA and CDCA. This is in contrast to cultured HepG2 cells,which release large amounts of bile acid precursors and unconjugated bile acids into the medium.

  4. Hepatitis B virus polymerase inhibits RIG-I- and Toll-like receptor 3-mediated beta interferon induction in human hepatocytes through interference with interferon regulatory factor 3 activation and dampening of the interaction between TBK1/IKKepsilon and DDX3.

    Science.gov (United States)

    Yu, Shiyan; Chen, Jieliang; Wu, Min; Chen, Hui; Kato, Nobuyuki; Yuan, Zhenghong

    2010-08-01

    Hepatitis B virus (HBV) infection remains one of the most serious health problems worldwide. Whilst studies have shown that HBV impairs interferon (IFN) production from dendritic cells in chronic hepatitis B patients, it remains unknown whether HBV inhibits IFN production in human hepatocytes. Using transient transfection assays in a primary human hepatocyte cell line (PH5CH8), this study demonstrated that HBV polymerase inhibits IFN-beta promoter activity induced by Newcastle disease virus, Sendai virus or poly(I : C) in a dose-dependent manner, whilst ectopic expression of the HBV core and X proteins had no effect on IFN-beta promoter activity. In addition, HBV polymerase blocked cellular IFN-beta expression and consequent antiviral immunity revealed by an infection protection assay. Furthermore, overexpression of key molecules on the IFN-beta induction axis, together with HBV polymerase, resulted in a block of IFN-beta promoter activity triggered by RIG-I, IPS-1, TRIF, TBK1 and IKKepsilon, but not by an IFN regulatory factor 3 dominant-positive mutant (IRF3-5D), suggesting that HBV polymerase prevents IFN-beta expression at the TBK1/IKKepsilon level. Further studies showed that HBV polymerase inhibited phosphorylation, dimerization and nuclear translocation of IRF3, in response to Sendai virus infection. Finally, it was shown that HBV polymerase-mediated dampening of the interaction between TBK1/IKKepsilon and DDX3 may be involved in the inhibitory effect on IFN-beta induction. Taken together, these findings reveal a novel role of HBV polymerase in HBV counteraction of IFN-beta production in human hepatocytes.

  5. Molecular cytotoxic mechanisms of chlorpromazine in isolated rat hepatocytes.

    Science.gov (United States)

    MacAllister, Stephanie L; Young, Cheryl; Guzdek, Anna; Zhidkov, Nickholas; O'Brien, Peter J

    2013-01-01

    Chlorpromazine (CPZ), a member of the largest class of first-generation antipsychotic agents, is known to cause hepatotoxicity in the form of cholestasis and hepatocellular necrosis in some patients. The mechanism of CPZ hepatotoxicity is unclear, but is thought to result from reactive metabolite formation. The goal of this research was to assess potential cytotoxic mechanisms of CPZ using the accelerated cytotoxicity mechanism screening (ACMS) technique with freshly isolated rat hepatocytes. This study identified CPZ cytotoxicity and inhibition of mitochondrial membrane potential (MMP) to be concentration-dependent. Furthermore, inhibition of cytochrome P450s (CYPs), including CYP2D1 and 1A2, delayed CPZ cytotoxicity, suggesting a role for CYP activation of CPZ to a toxic metabolite(s) in this model. Metabolism studies also demonstrated glucuronide and glutathione (GSH) requirement for CPZ detoxification in hepatocytes. Inactivating the 2-electron reduction pathway, NAD(P)H quinone oxidoreductase (NQO1), caused a significant increase in hepatocyte susceptibility to CPZ, indicating quinoneimine contribution to CPZ cytotoxicity. Nontoxic concentrations of peroxidase/H(2)O(2) (inflammatory model) increased cytotoxicity in CPZ-treated hepatocytes and caused additional mitochondrial toxicity. Inflammation further depleted GSH and increased oxidized glutathione (GSSG) levels. Results suggest activation of CPZ to reactive metabolites by 2 pathways in hepatocytes: (i) a CYP-catalyzed quinoneimine pathway, and (ii) a peroxidase-catalyzed oxidation of CPZ to CPZ radicals.

  6. Effect of nonsteroidal anti-inflammatory drugs on glycogenolysis in isolated hepatocytes.

    OpenAIRE

    Brass, E. P.; Garrity, M. J.

    1985-01-01

    E-series prostaglandins have previously been demonstrated to inhibit hormone-stimulated glycogenolysis when added to isolated hepatocytes of the rat. In the present study, the effect of nonsteroidal anti-inflammatory drugs, which inhibit cyclo-oxygenase activity, on glycogenolysis was examined in the hepatocyte model. Ibuprofen (80 microM), indomethacin (50 microM) and meclofenamate (60 microM) all increased rates of glycogenolysis when added under basal conditions. In contrast, piroxicam (50...

  7. Genetic abolishment of hepatocyte proliferation activates hepatic stem cells.

    Directory of Open Access Journals (Sweden)

    Yoko Endo

    Full Text Available Quiescent hepatic stem cells (HSCs can be activated when hepatocyte proliferation is compromised. Chemical injury rodent models have been widely used to study the localization, biomarkers, and signaling pathways in HSCs, but these models usually exhibit severe promiscuous toxicity and fail to distinguish damaged and non-damaged cells. Our goal is to establish new animal models to overcome these limitations, thereby providing new insights into HSC biology and application. We generated mutant mice with constitutive or inducible deletion of Damaged DNA Binding protein 1 (DDB1, an E3 ubiquitin ligase, in hepatocytes. We characterized the molecular mechanism underlying the compensatory activation and the properties of oval cells (OCs by methods of mouse genetics, immuno-staining, cell transplantation and gene expression profiling. We show that deletion of DDB1 abolishes self-renewal capacity of mouse hepatocytes in vivo, leading to compensatory activation and proliferation of DDB1-expressing OCs. Partially restoring proliferation of DDB1-deficient hepatocytes by ablation of p21, a substrate of DDB1 E3 ligase, alleviates OC proliferation. Purified OCs express both hepatocyte and cholangiocyte markers, form colonies in vitro, and differentiate to hepatocytes after transplantation. Importantly, the DDB1 mutant mice exhibit very minor liver damage, compared to a chemical injury model. Microarray analysis reveals several previously unrecognized markers, including Reelin, enriched in oval cells. Here we report a genetic model in which irreversible inhibition of hepatocyte duplication results in HSC-driven liver regeneration. The DDB1 mutant mice can be broadly applied to studies of HSC differentiation, HSC niche and HSCs as origin of liver cancer.

  8. Metabolism of dicarboxylic acids in rat hepatocytes.

    Science.gov (United States)

    Bergseth, S; Poisson, J P; Bremer, J

    1990-02-06

    [carboxyl-14C]Dodecanedioic acid (DC12) is metabolized in hepatocytes at a rate about two thirds that of [1-14C]palmitate. Shorter dicarboxylates (sebacic (DC10), suberic (DC8), and adipic (DC6) acid) are formed, mainly DC6, less DC8 and only a little DC10. In hepatocytes from clofibrate-treated rats, more polar products account for most of the breakdown products, presumably because the beta-oxidation proceeds all the way to succinate and acetyl-CoA. [carboxyl-14C]Suberic acid (DC8) is oxidized at a rate only one fifth that of dodecanedioic acid. (+)-Decanoylcarnitine inhibits palmitate oxidation but not the oxidation of dodecanedioic acid. At low concentrations of [carboxyl-14C]dodecanedioic acid or of [1-14C]palmitate, acetylsulfanilamide is more efficiently labeled by the former. High concentrations of dodecanedioic acid inhibit palmitate oxidation and the acetylation of sulfanilamide, presumably because their CoA-esters accumulate in the cytosol. These results indicate that medium-chain dicarboxylic acids are beta-oxidized mainly in the peroxisomes.

  9. Cancer-Associated Fibroblasts Regulate Tumor-Initiating Cell Plasticity in Hepatocellular Carcinoma through c-Met/FRA1/HEY1 Signaling

    Directory of Open Access Journals (Sweden)

    Eunice Yuen Ting Lau

    2016-05-01

    Full Text Available Like normal stem cells, tumor-initiating cells (T-ICs are regulated extrinsically within the tumor microenvironment. Because HCC develops primarily in the context of cirrhosis, in which there is an enrichment of activated fibroblasts, we hypothesized that cancer-associated fibroblasts (CAFs would regulate liver T-ICs. We found that the presence of α-SMA(+ CAFs correlates with poor clinical outcome. CAF-derived HGF regulates liver T-ICs via activation of FRA1 in an Erk1,2-dependent manner. Further functional analysis identifies HEY1 as a direct downstream effector of FRA1. Using the STAM NASH-HCC mouse model, we find that HGF-induced FRA1 activation is associated with the fibrosis-dependent development of HCC. Thus, targeting the CAF-derived, HGF-mediated c-Met/FRA1/HEY1 cascade may be a therapeutic strategy for the treatment of HCC.

  10. Current status of hepatocyte xenotransplantation.

    Science.gov (United States)

    Meier, Raphael P H; Navarro-Alvarez, Nalu; Morel, Philippe; Schuurman, Henk-Jan; Strom, Stephen; Bühler, Leo H

    2015-11-01

    The treatment of acute liver failure, a condition with high mortality, comprises optimal clinical care, and in severe cases liver transplantation. However, there are limitations in availability of organ donors. Hepatocyte transplantation is a promising alternative that could fill the medical need, in particular as the bridge to liver transplantation. Encapsulated porcine hepatocytes represent an unlimited source that could function as a bioreactor requiring minimal immunosuppression. Besides patients with acute liver failure, patients with alcoholic hepatitis who are unresponsive to a short course of corticosteroids are a target for hepatocyte transplantation. In this review we present an overview of the innate immune barriers in hepatocyte xenotransplantation, including the role of complement and natural antibodies; the role of phagocytic cells and ligands like CD47 in the regulation of phagocytic cells; and the role of Natural Killer cells. We present also some illustrations of physiological species incompatibilities in hepatocyte xenotransplantation, such as incompatibilities in the coagulation system. An overview of the methodology for cell microencapsulation is presented, followed by proof-of-concept studies in rodent and nonhuman primate models of fulminant liver failure: these studies document the efficacy of microencapsulated porcine hepatocytes which warrants progress towards clinical application. Lastly, we present an outline of a provisional clinical trial, that upon completion of preclinical work could start within the upcoming 2-3 years.

  11. Increased NQO1 but Not c-MET and Survivin Expression in Non-Small Cell Lung Carcinoma with KRAS Mutations

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    Ahmet Yilmaz

    2014-09-01

    Full Text Available Cigarette smoking is one of the most significant public health issues and the most common environmental cause of preventable cancer deaths worldwide. EGFR (Epidermal Growth Factor Receptor-targeted therapy has been used in the treatment of LC (lung cancer, mainly caused by the carcinogens in cigarette smoke, with variable success. Presence of mutations in the KRAS (Kirsten rat sarcoma viral oncogene homolog driver oncogene may confer worse prognosis and resistance to treatment for reasons not fully understood. NQO1 (NAD(PH:quinone oxidoreductase, also known as DT-diaphorase, is a major regulator of oxidative stress and activator of mitomycins, compounds that have been targeted in over 600 pre-clinical trials for treatment of LC. We sequenced KRAS and investigated expression of NQO1 and five clinically relevant proteins (DNMT1, DNMT3a, ERK1/2, c-MET, and survivin in 108 patients with non-small cell lung carcinoma (NSCLC. NQO1, ERK1/2, DNMT1, and DNMT3a but not c-MET and survivin expression was significantly more frequent in patients with KRAS mutations than those without, suggesting the following: (1 oxidative stress may play an important role in the pathogenesis, worse prognosis, and resistance to treatment reported in NSCLC patients with KRAS mutations, (2 selecting patients based on their KRAS mutational status for future clinical trials may increase success rate, and (3 since oxidation of nucleotides also specifically induces transversion mutations, the high rate of KRAS transversions in lung cancer patients may partly be due to the increased oxidative stress in addition to the known carcinogens in cigarette smoke.

  12. ERO1α及其 DNA 甲基化在同型半胱氨酸抑制肝细胞增殖中的作用%Role of ERO1αand its DNA methylation in homocysteine-induced inhibition of hepatocyte proliferation

    Institute of Scientific and Technical Information of China (English)

    赵丽; 杨晓玲; 姜怡邓; 曹成建; 刘现梅; 孔繁琪; 马文斌; 周龙霞; 陈久凯; 张鸣号; 焦运

    2014-01-01

    目的:探讨内质网氧化还原酶-1α(endoplasmic reticu-lum oxidoreductin 1-α,ERO1α)及其 DNA 甲基化在同型半胱氨酸(homocysteine,Hcy)抑制肝细胞增殖中的作用。方法以0μmol·L -1 Hcy 为正常对照组(NC group),以100μmol ·L -1 Hcy 为干预组(Hcy group),干预肝细胞48h 后,四甲基偶氮唑盐比色法(MTT)检测肝细胞增殖活力的变化;实时定量聚合酶链反应(qRT-PCR)及 Western blot 分别检测ERO1αmRNA 和蛋白表达水平;构建 ERO1α真核表达质粒,转染肝细胞后,荧光显微镜下观察转染效率并以 qRT-PCR 及 Western blot 验证 ERO1α是否过表达,后用 MTT 法检测肝细胞增殖活力的变化;巢式降落式甲基化特异性 PCR (ntMS-PCR)检测 ERO1αDNA 甲基化水平。结果与正常对照组相比,Hcy 干预组肝细胞内 ERO1αmRNA 及蛋白表达水平降低,且细胞增殖活力减弱(P <0.01)。测序结果证明 ERO1α重组质粒构建成功,荧光显微镜下可见绿色荧光蛋白大量表达,qRT-PCR 及 Western blot 验证结果显示ERO1α过表达(P <0.01),而 MTT 法结果表明 ERO1α过表达可缓解 Hcy 导致的肝细胞增殖抑制(P <0.01)。Hcy 刺激后 ERO1αDNA 甲基化水平升高(P <0.05)。结论Hcy通过下调 ERO1α表达抑制肝细胞增殖,而 ERO1α启动子区DNA 甲基化是其重要的调控机制。%Aim To explore the role of ERO1 αand its DNA methylation in homocysteine (Hcy)-induced in-hibition of hepatocytes proliferation.Methods The hepatocytes stimulated with 0 μmol·L -1 Hcy were set as the normal group (NC group)and the hepatocytes stimulated with 1 00 μmol·L -1 Hcy as the experimen-tal group (Hcy group).Methyl thiazolyl tetrazolium (MTT)reduction assay was used to reflect the prolifer-ation of the hepatocytes;qRT-PCR and Western blot were used to detect the mRNA and protein levels of ERO1 α;the expression of green fluorescence protein

  13. The Mechanism of Gefitinib Resistance Induced by Hepatocyte Growth Factor 
in Sensitive Non-small Cell Lung Cancer Cells in Vitro

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    Xianglan XUAN

    2013-01-01

    Full Text Available Background and objective Previous studies have reported that Met might be related to gefitinib resistance in non-small cell lung cancer (NSCLC. The present study aims to explore the mechanism of hepatocyte growth factor (HGF-induced gefitinib resistance in different gene types of sensitive NSCLC in vitro. Methods The PC-9 and H292 cell lines were chosen and induced by HGF. The cell survival was measured using MTT assay, the cell cycle distribution was measured using PI assay, and cell apoptosis with an Annexin V-PE assay, respectively. The c-Met and p-Met protein expression was determined via Western blot analysis. Results Gefitinib inhibited the growth of PC-9 and H292 cells in a dose-dependent manner. The concentration-survival curves of both cell lines shifted to the right when induced with HGF. HGF did not affect PC-9 and H292 cell proliferation. The cell also had a higher cell survival rate when treated with HGF and gefitinib compared with that under gefitinib alone (P<0.05. The apoptotic rate and cell cycle progression showed no significant difference between the HG and G group (P>0.05. HGF stimulated Met phosphorylation in the PC-9 and H292 cells. Gefitinib inhibited the HGF-induced Met phosphorylation in PC-9 cells, but not in H292 cells. Conclusion HGF induces gefitinib resistance in PC-9 and H292 cells. HGF-induced Met phosphorylation may be an important mechanism of gefitinib resistance in sensitive NSCLC.

  14. Endotoxin-stimulated Rat Hepatic Stellate Cells Induce Autophagy in Hepatocytes as a Survival Mechanism.

    Science.gov (United States)

    Dangi, Anil; Huang, Chao; Tandon, Ashish; Stolz, Donna; Wu, Tong; Gandhi, Chandrashekhar R

    2016-01-01

    Bacterial lipopolysaccharide (LPS)-stimulated hepatic stellate cells (HSCs) produce many cytokines including IFNβ, TNFα, and IL6, strongly inhibit DNA synthesis, but induce apoptosis of a small number of hepatocytes. In vivo administration of LPS (up to 10 mg/mL) causes modest inflammation and weight loss in rats but not mortality. We determined whether LPS-stimulated HSCs instigate mechanisms of hepatocyte survival. Rats received 10 mg/kg LPS (i.p.) and determinations were made at 6 h. In vitro, HSCs were treated with 100 ng/mL LPS till 24 h. The medium was transferred to hepatocytes, and determinations were made at 0-12 h. Controls were HSC-conditioned medium or medium-containing LPS. LPS treatment of rats caused autophagy in hepatocytes, a physiological process for clearance of undesirable material including injured or damaged organelles. This was accompanied by activation of c-Jun NH2 terminal kinase (JNK) and apoptosis of ~4-5% of hepatocytes. In vitro, LPS-conditioned HSC medium (LPS/HSC) induced autophagy in hepatocytes but apoptosis of only ~10% of hepatocytes. While LPS/HSC stimulated activation of JNK (associated with cell death), it also activated NFkB and ERK1/2 (associated with cell survival). LPS-stimulated HSCs produced IFNβ, and LPS/HSC-induced autophagy in hepatocytes and their apoptosis were significantly inhibited by anti-IFNβ antibody. Blockade of autophagy, on the other hand, strongly augmented hepatocyte apoptosis. While LPS-stimulated HSCs cause apoptosis of a subpopulation of hepatocytes by producing IFNβ, they also induce cell survival mechanisms, which may be of critical importance in resistance to liver injury during endotoxemia.

  15. Expression of c-Met in Endemic Kaposi's Sarcoma and AIDS-related Kaposi's Sarcoma%c-Met蛋白和c-Met mRNA在地方性及艾滋病相关性Kaposi肉瘤中的表达

    Institute of Scientific and Technical Information of China (English)

    张树华; 阮幼冰; 武忠弼; J.N Kitinya; 马云; 朱玉红; 吕增华

    2003-01-01

    目的探讨c-Met原癌基因蛋白和c-Met mRNA在地方性及艾滋病相关性Kaposi肉瘤不同期的表达.方法对源自坦桑尼亚首都Muhimbili医疗中心病理科的30份标本,用免疫组化、原位杂交方法进行了研究.结果根据Kaposi肉瘤组织中血管成分和梭形细胞的比例分为早期血管瘤样型(11个病灶)、晚期梭形细胞型(14个病灶)和中期混合型(13个病灶).c-Met蛋白在早期表达弱,晚期表达强,中期介于两者之间,相互间差异有非常显著性(P<0.01);c-Met mRNA在不同期的表达与c-Met蛋白的表达类似.c-Met蛋白和c-Met mRNA在地方性和艾滋病相关性Kaposi肉瘤的表达差异无显著性(P>0.05).结论c-Met表达的改变在地方性和艾滋病相关性Kaposi肉瘤的发生发展过程中起了作用.

  16. CYP2E1-dependent hepatotoxicity and oxidative damage after ethanol administration in human primary hepatocytes

    Institute of Scientific and Technical Information of China (English)

    Lie-Gang Liu; Hong Yan; Ping Yao; Wen Zhang; Li-Jun Zou; Fang-Fang Song; Ke Li; Xiu-Fa Sun

    2005-01-01

    AIM: To observe the relationship between ethanol-induced oxidative damage in human primary cultured hepatocytes and cytochrome P450 2E1 (CYP2E1) activity, in order to address if inhibition of CYP2E1 could attenuate ethanol-induced cellular damage.METHODS: The dose-dependent (25-100 mmol/L) and time-dependent (0-24 h) exposures of primary human cultured hepatocytes to ethanol were carried out. CYP2E1 activity and protein expression were detected by spectrophotometer and Western blot analysis respectively.Hepatotoxicity was investigated by determination of lactate dehydrogenase (LDH) and aspartate transaminase (AST) level in hepatocyte culture supernatants, as well as the intracellular formation of malondialdehyde (MDA).RESULTS: A dose-and time-dependent response between ethanol exposure and CYP2E1 activity in human hepatocytes was demonstrated. Moreover, there was a time-dependent increase of CYP2E1 protein after 100 mmol/L ethanol exposure. Meanwhile, ethanol exposure of hepatocytes caused a time-dependent increase of ceilular MDA level, LDH, and AST activities in supernatants.Furthermore, the inhibitor of CYP2E1, diallyl sulfide (DAS) could partly attenuate the increases of MDA, LDH, and AST in human hepatocytes.CONCLUSION: A positive relationship between ethanol-induced oxidative aamage in human primary cultured hepatocytes and CYP2E1 activity was exhibited, and the inhibition of CYP2E1 could partly attenuate ethanol-induced oxidative damage.

  17. Sodium-independent, bicuculline-sensitive (/sup 3/H)GABA binding to isolated rat hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Minuk, G.Y.; Bear, C.E.; Sarjeant, E.J.

    1987-05-01

    To determine whether hepatocytes possess specific receptor sites for gamma-aminobutyric acid (GABA), a potent amino acid neurotransmitter, (/sup 3/H)GABA, was added to sodium-free suspensions of Percoll-purified hepatocytes derived from collagenase-perfused rat livers under various experimental conditions and in the presence or absence of specific GABA receptor agonists (muscimol) and antagonists (bicuculline). The effects of GABA, muscimol, and bicuculline on hepatocyte resting membrane potentials were also determined. Specific binding of (/sup 3/H)GABA to hepatocytes was a consistent finding. GABA-hepatocyte interactions were reversible and temperature dependent. Muscimol and bicuculline inhibited binding in a dose-dependent manner (IC50, 30 nM and 50 microM, respectively), whereas strychnine (1.0-100 microM), a nonspecific central nervous system stimulant, had no appreciable effect. Both GABA and muscimol (100 microM) caused significant hyperpolarization of hepatocyte resting membrane potential (delta PD 5.4 +/- 3.1 and 22.2 +/- 16.2 mV, respectively, means +/- SD, P less than 0.0005). Bicuculline (100 microM) inhibited the effect of muscimol (P less than 0.05). The results of this study suggest that specific GABA receptor sites exist on the surface of isolated rat hepatocytes. The presence of such sites raises the possibility that, in addition to adrenergic and cholinergic innervation, hepatic function may be influenced by GABA-ergic neurotransmitter mechanisms.

  18. Antifolate/folate-activated HGF/c-Met signalling pathways in mouse kidneys-the putative role of their downstream effectors in cross-talk with androgen receptor.

    Science.gov (United States)

    Dudkowska, Magdalena; Bajer, Seweryn; Jaworski, Tomasz; Zielińska, Joanna; Manteuffel-Cymborowska, Małgorzata; Grzelakowska-Sztabert, Barbara

    2009-03-01

    This in vivo study of mouse kidneys was focused on the identification of protein mediators involved in the cross-talk between two signalling pathways. One pathway was triggered by testosterone via an androgen receptor, AR, and the other induced by CB 3717/folate via HGF, and its membrane receptor c-Met. Sequential activation of these pathways leads to a drastic decrease of testosterone-induced ornithine decarboxylase, ODC, expression. We proved that CB 3717/folate-induced ODC expression is Akt-dependent. CB 3717/folate activates Akt and ERK1/2 kinases, PTEN phosphatase and also up-regulates cyclin D2 and PCNA, but decreases GSK3beta and cyclin D1 protein levels. Testosterone activation of AR induces GSK3beta and PTEN. Results of the sequential activation of the studied signalling pathways suggest that Akt, GSK3beta and possibly ERK1/2 kinases may participate in the negative cross-talk and attenuation of AR transactivity, while the involvement of PTEN and cyclin D1 seems to be doubtful.

  19. Overexpression of NK2 inhibits liver regeneration after partial hepatectomy in mice

    Institute of Scientific and Technical Information of China (English)

    Toshiyuki Otsuka; Hitoshi Takagi; Glenn Merlino; Masatomo Mori; Norio Horiguchi; Daisuke Kanda; Takashi Kosone; Yuichi Yamazaki; Kazuhisa Yuasa; Naondo Sohara; Satoru Kakizaki; Ken Sato

    2005-01-01

    AIM: To investigate the in vivo effects of NK2 on liver regeneration after partial hepatectomy (PH). METHODS: Survival after PH was observed with 21 NK2 transgenic mice and 23 wild-type (WT) mice over 10 d. Liver regeneration was analyzed using histology and immunohistochemistry. Expressions of genes were analyzed using Northern blot analysis, immunoprecipitation and immunoblotting, and reverse transcriptase polymerase chain reaction assay. KaplanMeier method and the log-rank test were used for ahalyzing the survival after PH. Differences in the resultsof immunohistochemistry and percentage of liver regeneration was determined by the Student's t-test. RESULTS: More than half of NK2 transgenic mice died within 48 h after PH. After PH, increased deposition of small lipid droplets in hepatocytes was evident and hepatic proliferation was inhibited in NK2 transgenic mice. The hepatic expression and kinase activity of HGF receptor, c-Met, were unchanged among WT mice and NK2 transgenic mice after PH. The expression of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in liver tissues were prolonged in NK2 transgenic mice that died after PH.CONCLUSION: Our findings indicate that overexpression of NK2 inhibits liver regeneration after PH.

  20. Hepatocyte growth factor protects endothelial cells against gamma ray irradiation-induced damage

    Institute of Scientific and Technical Information of China (English)

    Shun-ying HU; Hai-feng DUAN; Qing-fang LI; Yue-feng YANG; Jin-long CHEN; Li-sheng WANG; Hua WANG

    2009-01-01

    Aim:To investigate the effect of HGF on proliferation, apoptosis and migratory ability of human vascular endothelial cells against gamma ray irradiation.Methods: ECV304 cells derived from adult human umbilical vein endothelial cells (HUVEC) were irradiated with a single gamma ray dose of 20 Gy. Immunocytochemistry and Western blot analysis were used to detect c-Met protein expression and HGF/c-Met signal pathway. In the HGF-treated groups, ECV304 cells were incubated with HGF (20 or 40 ng/mL) 3 h prior to irradiation. At 48 h post-irradiation, the proliferation of ECV304 cells was measured by MTT assay, the apoptosis was assessed by flow cytometry, and the migratory ability of ECV304 cells was measured by transwell chamber assay.Results: c-Met protein is expressed in ECV304 cells and can be activated by HGF. Gamma ray irradiation inhibits proliferation and migration of ECV304 cells in a dose-dependent manner. HGF significantly promoted the proliferation of ECV304 cells, and flow cytom-etry revealed that HGF can inhibit apoptosis of ECV304 cells. Transwell chamber assay also showed that HGF increases migration activity of endothelial cells.Conclusion: HGF may afford protection to vascular endothelial cells against gamma ray irradiation-induced damage.

  1. Response of porcine hepatocytes in primary culture to plasma from severe viral hepatitis patients

    Institute of Scientific and Technical Information of China (English)

    Yong-Bo Cheng; Ying-Jie Wang; Shi-Chang Zhang; Jun Liu; Zhi Chen; Jia-Jia Li

    2005-01-01

    AIM: To observe the effects of plasma from patients with severe viral hepatitis (SVHP) on the growth and metabolism of porcine hepatocytes and the clinical efficiency of bioartificial liver device.METHODS: Hepatocytes were isolated from male porcines by collagenase perfusion. The synthesis of DNA and total protein, leakages of AST and LDH, changes in glutathione (GSH), catalase and morphology of porcine hepatocytes exposed to SVHP were investigated to indicate the effect of plasma from patients with severe hepatitis on the growth, injury, detoxification, and morphology of porcine hepatocytes.RESULTS: The synthesis of DNA and protein was inhibited in the medium containing 100% SVHP compared to the controls. The leakages of LDH and AST increased in porcine hepatocytes following exposure to 100% SVHP for 5 h. The difference between 100% SVHP and 10% newborn calf serum (NCS) was significant in t-test (LDH: t = 24.552, P = 0.001; AST: t = 4.169, P =0.014). After exposure to SVHP for 24 h, alterations in GSH status were significant (F = 2.746, P<0.05) between porcine hepatocytes in 100% SVHP and 10% NCS, but no alteration occurred in the culture medium after 48 h (F = 4.378, P<0.05). A similar profile was observed in catalase activity. Many round vacuoles were observed in porcine hepatocytes cultured in SVHP. The membranes of these cells became indistinct and almost all the cells died on d 5.CONCLUSION: Plasma from patients with severe hepatitis inhibits the growth, injures membrane, disturbs GSH homeostasis and induces morphological changes of porcine hepatocytes. It is suggested that SVHP should be pretreated to reduce the toxin load and improve the performance of porcine hepatocytes in extracorporeal liver-support devices.

  2. Preparation and property analysis of a hepatocyte targeting pH-sensitive liposome

    Institute of Scientific and Technical Information of China (English)

    Si-Yuan Wen; Xiao-Hong Wang; Li Lin; Wei Guan; Sheng-Qi Wang

    2004-01-01

    AIM: To develop a hepatocyte targeting pH-sensitive liposome for drug delivery based on active targeting technology mediated by asialoglycoprotein receptors.METHODS: Four types of targeting molecules with galactose residue were synthesized and mixed with pH-sensitive lipids DC-chol/DOPE to prepare liposome with integrated property of hepatocyte specificity and pH sensitivity. Liposome 18-gal was selected with the best transfection activity through cellular uptake experiment. Property analysis was made through experiments of competitive inhibition of receptors,red blood cell hemolysis,in vitro cytotoxicity test by MTS assay and mediation of inhibitory effects of antisense phosphorothioate ODN on gene expression, etc.RESULTS: Liposome L8-gal had the desired properties of hepatocyte specificity, pH sensitivity, low cytotoxicity, and high transfection efficiency.CONCLUSION: Liposome 18-gal can be further developed as a potential hepatocyte- targeting delivery system.

  3. Hepatocytes: critical for glucose homeostasis.

    Science.gov (United States)

    Klover, Peter J; Mooney, Robert A

    2004-05-01

    Maintaining blood glucose levels within a narrow range is a critical physiological function requiring multiple metabolic pathways and involving several cell types, including a prominent role for hepatocytes. Under hormonal control, hepatocytes can respond to either feeding or fasting conditions by storing or producing glucose as necessary. In the fasting state, the effects of glucagon avoid hypoglycemia by stimulating glucogenesis and glycogenolysis and initiating hepatic glucose release. Postprandially, insulin prevents hyperglycemia, in part, by suppressing hepatic gluconeogenesis and glycogenolysis and facilitating hepatic glycogen synthesis. Both transcriptional regulation of rate limiting enzymes and modulation of enzyme activity through phosphorylation and allosteric regulation are involved. Type 2 diabetes mellitus is the most common serious metabolic condition in the world, and results from a subnormal response of tissues to insulin (insulin resistance) and a failure of the insulin-secreting beta cells to compensate. In type 2 diabetes, glucose is overproduced by the hepatocyte and is ineffectively metabolized by other organs. Impairments in the insulin signal transduction pathway appear to be critical lesions contributing to insulin resistance and type 2 diabetes.

  4. Piceatannol increases the expression of hepatocyte growth factor and IL-10 thereby protecting hepatocytes in thioacetamide-induced liver fibrosis.

    Science.gov (United States)

    Abd-Elgawad, Hazem; Abu-Elsaad, Nashwa; El-Karef, Amr; Ibrahim, Tarek

    2016-07-01

    Piceatannol is a polyphenolic analog of resveratrol that selectively inhibits the non-receptor tyrosine kinase-Syk. This study investigates the potential ability of piceatannol to attenuate liver fibrosis and protect hepatocytes from injury. Thioacetamide was injected in adult male mice (100 mg/kg, i.p., 3 times/week) for 8 weeks. Piceatannol (1 or 5 mg/kg per day) was administered by oral gavage during the last 4 weeks. Liver function biomarkers, tissue malondialdehyde (MDA), cytokeratin-18 (CK18), hepatocyte growth factor (HGF), and interleukin-10 (IL-10) were measured. Necroinflammation, fibrosis, expression of transforming growth factor (TGF)-β1, and α-smooth muscle actin (SMA) were scored by histopathological examination and immunohistochemistry. Obtained results showed ability of piceatannol (1 mg/kg) to restore liver function and reduce inflammation. It significantly (p IL-10. It can be concluded that piceatannol at low dose can inhibit TGF-β1 induced hepatocytes apoptosis and exerts an anti-inflammatory effect attenuating fibrosis progression.

  5. Inhibitory effects of berberine on ion channels of rat hepatocytes

    Institute of Scientific and Technical Information of China (English)

    Fang Wang; Hong-Yi Zhou; Gang Zhao; Li-Ying Fu; Lan Cheng; Jian-Guo Chen; Wei-Xing Yao

    2004-01-01

    AIM: To examine the effects of berberine, an isoquinoline alkaloid with a long history used as a tonic remedy for liver and heart, on ion channels of isolated rat hepatocytes.METHODS: Tight-seal whole-cell patch-clamp techniques were performed to investigate the effects of berberine on the delayed outward potassium currents (IK), inward rectifier potassium currents (IK1) and Ca2+ release-activated Ca2+currents (ICRAC) in enzymatically isolated rat hepatocytes.RESULTS: Berberine 1-300 nmol/L reduced IK in a concentration dependent manner with EC50 of 38.86±5.37 μmol/L and nH of 0.82±0.05 (n = 8). When the bath solution was changed to tetraethylammonium (TEA) 8 mmol/L, IK was inhibited.Berberine 30 μmol/L reduced IK at all examined membrane potentials, especially at potentials positive to +60 mV (n = 8,P<0.05 or P<0.01 vs control). Berberine had mild inhibitory effects on IK1 in rat hepatocytes. Berberine 1-300 μmol/L also inhibited ICRAC in a concentration-dependent fashion.The fitting parameters were EC50 = 47.20±10.86 μmol/L,nH = 0.71±0.09 (n = 8). The peak value of ICRAC in the Ⅰ-Ⅴrelationship was decreased by berberine 30 μmol/L at potential negative to -80 mV (n = 8, P<0.05 vscontrol). But the reverse potential of ICRAC occurred at voltage 0 mV in all cells.CONCLUSION: Berberine has inhibitory effects on potassium and calcium currents in isolated rat hepatocytes, which may be involved in hepatoprotection.

  6. Hepatocyte Growth Factor Effects on Mesenchymal Stem Cells Derived from Human Arteries: A Novel Strategy to Accelerate Vascular Ulcer Wound Healing

    Directory of Open Access Journals (Sweden)

    Sabrina Valente

    2016-01-01

    Full Text Available Vascular ulcers are a serious complication of peripheral vascular disease, especially in diabetics. Several approaches to treat the wounds are proposed but they show poor outcomes and require long healing times. Hepatocyte Growth Factor/Scatter Factor (HGF/SF is a pleiotropic cytokine exerting many biological activities through the c-Met receptor. This study was aimed at verifying whether HGF/SF influences proliferation, migration, and angiogenesis on mesenchymal stem cells isolated from human arteries (hVW-MSCs. hVW-MSCs were exposed to NIBSC HGF/SF (2.5, 5, 10, and 70 ng/mL from 6 hrs to 7 days. HGF and c-MET mRNA and protein expression, cell proliferation (Alamar Blue and Ki–67 assay, migration (scratch and transwell assays, and angiogenesis (Matrigel were investigated. hVW-MSCs displayed stemness features and expressed HGF and c-MET. HGF/SF did not increase hVW-MSC proliferation, whereas it enhanced the cell migration, the formation of capillary-like structures, and the expression of angiogenic markers (vWF, CD31, and KDR. The HGF/SF effects on hVW-MSC migration and angiogenic potential are of great interest to accelerate wound healing process. Local delivery of HGF/SF could therefore improve the healing of unresponsive vascular ulcers.

  7. Hepatocyte Growth Factor Effects on Mesenchymal Stem Cells Derived from Human Arteries: A Novel Strategy to Accelerate Vascular Ulcer Wound Healing.

    Science.gov (United States)

    Valente, Sabrina; Ciavarella, Carmen; Pasanisi, Emanuela; Ricci, Francesca; Stella, Andrea; Pasquinelli, Gianandrea

    2016-01-01

    Vascular ulcers are a serious complication of peripheral vascular disease, especially in diabetics. Several approaches to treat the wounds are proposed but they show poor outcomes and require long healing times. Hepatocyte Growth Factor/Scatter Factor (HGF/SF) is a pleiotropic cytokine exerting many biological activities through the c-Met receptor. This study was aimed at verifying whether HGF/SF influences proliferation, migration, and angiogenesis on mesenchymal stem cells isolated from human arteries (hVW-MSCs). hVW-MSCs were exposed to NIBSC HGF/SF (2.5, 5, 10, and 70 ng/mL) from 6 hrs to 7 days. HGF and c-MET mRNA and protein expression, cell proliferation (Alamar Blue and Ki-67 assay), migration (scratch and transwell assays), and angiogenesis (Matrigel) were investigated. hVW-MSCs displayed stemness features and expressed HGF and c-MET. HGF/SF did not increase hVW-MSC proliferation, whereas it enhanced the cell migration, the formation of capillary-like structures, and the expression of angiogenic markers (vWF, CD31, and KDR). The HGF/SF effects on hVW-MSC migration and angiogenic potential are of great interest to accelerate wound healing process. Local delivery of HGF/SF could therefore improve the healing of unresponsive vascular ulcers.

  8. CM2 antigen, a potential novel molecule participating in glucuronide transport on rat hepatocyte canalicular membrane

    Directory of Open Access Journals (Sweden)

    L. Wang

    2012-06-01

    Full Text Available The polarized molecules predominately distributing at hepatocyte canalicular surface play a vital role in disclosing the process of bile formation and etiopathogenisis of cholestatic live diseases. Therefore, it is important to find novel polarized molecules on hepatocyte canalicular membrane. In the present study, canalicular membrane vesicles (CMVs isolated from rat hepatocyte by density gradient centrifugation were used as immunogens to produce hybridoma and 46 strains of monoclonal antibodies (mAb against CMVs were obtained. With a series of morphological assay methods, including immunohistochemistry, immunofluorescence and immuno-electron microscope, the antigens recognized by canalicular mAb1 (CM1 and canalicular mAb2 (CM2 were confirmed to predominately distribute at hepatocyte canalicular membrane. Transport activity assay revealed that CM2 could inhibit ATP-dependent E217βG uptake of rat hepatocyte CMVs. Meanwhile, Western blotting analysis showed that the molecular mass of CM2 antigen was approximately 110kDa, which was much less than Mr 180kDa of multidrug resistance-associated protein 2 (MRP2 involved in glucuronide transport. These data indicated that CM2 antigen might be a potential novel molecule participating in glucuronide transport on the hepatocyte canalicular membrane.

  9. Protection of hepatocytes from cytotoxic T cell mediated killing by interferon-alpha.

    Directory of Open Access Journals (Sweden)

    Christian B Willberg

    Full Text Available BACKGROUND: Cellular immunity plays a key role in determining the outcome of hepatitis C virus (HCV infection, although the majority of infections become persistent. The mechanisms behind persistence are still not clear; however, the primary site of infection, the liver, may be critical. We investigated the ability of CD8+ T-cells (CTL to recognise and kill hepatocytes under cytokine stimulation. METHODS/PRINCIPLE FINDINGS: Resting hepatocytes cell lines expressed low levels of MHC Class I, but remained susceptible to CTL cytotoxicity. IFN-alpha treatment, in vitro, markedly increased hepatocyte MHC Class I expression, however, reduced sensitivity to CTL cytotoxicity. IFN-alpha stimulated hepatocyte lines were still able to present antigen and induce IFN-gamma expression in interacting CTL. Resistance to killing was not due to the inhibition of the FASL/FAS- pathway, as stimulated hepatocytes were still susceptible to FAS-mediated apoptosis. In vitro stimulation with IFN-alpha, or the introduction of a subgenomic HCV replicon into the HepG2 line, upregulated the expression of the granzyme-B inhibitor-proteinase inhibitor 9 (PI-9. PI-9 expression was also observed in liver tissue biopsies from patients with chronic HCV infection. CONCLUSION/SIGNIFICANCE: IFN-alpha induces resistance in hepatocytes to perforin/granzyme mediate CTL killing pathways. One possible mechanism could be through the expression of the PI-9. Hindrance of CTL cytotoxicity could contribute to the chronicity of hepatic viral infections.

  10. Mechanisms and prevention of hepatocyte cell death

    NARCIS (Netherlands)

    Vrenken, Titia Eveline

    2008-01-01

    In many liver diseases, hepatocyte damage occurs upon exposure to toxic bile acids, inflammatory cytokines and increased levels of reactive oxygen species (ROS). Detailed information of the signaling pathways involved in hepatocyte damage will facilitate the discovery of new targets for intervention

  11. Adropin induction of lipoprotein lipase expression in tilapia hepatocytes.

    Science.gov (United States)

    Lian, Anji; Wu, Keqiang; Liu, Tianqiang; Jiang, Nan; Jiang, Quan

    2016-01-01

    The peptide hormone adropin plays a role in energy homeostasis. However, biological actions of adropin in non-mammalian species are still lacking. Using tilapia as a model, we examined the role of adropin in lipoprotein lipase (LPL) regulation in hepatocytes. To this end, the structural identity of tilapia adropin was established by 5'/3'-rapid amplification of cDNA ends (RACE). The transcripts of tilapia adropin were ubiquitously expressed in various tissues with the highest levels in the liver and hypothalamus. The prolonged fasting could elevate tilapia hepatic adropin gene expression, whereas no effect of fasting was observed on hypothalamic adropin gene levels. In primary cultures of tilapia hepatocytes, synthetic adropin was effective in stimulating LPL release, cellular LPL content, and total LPL production. The increase in LPL production also occurred with parallel rises in LPL gene levels. In parallel experiments, adropin could elevate cAMP production and up-regulate protein kinase A (PKA) and PKC activities. Using a pharmacological approach, cAMP/PKA and PLC/inositol trisphosphate (IP3)/PKC cascades were shown to be involved in adropin-stimulated LPL gene expression. Parallel inhibition of p38MAPK and Erk1/2, however, were not effective in these regards. Our findings provide, for the first time, evidence that adropin could stimulate LPL gene expression via direct actions in tilapia hepatocytes through the activation of multiple signaling mechanisms.

  12. Effect of sodium citrate plasma on growth and function of hepatocytes

    Institute of Scientific and Technical Information of China (English)

    CHENG Yong-bo; WANG Ying-jie; CHEN Zhi; ZHANG Shi-chang; CHEN Guo-zhi; LEI Juan

    2006-01-01

    Objective:To observe the effect of sodium citrate plasma (scP) on the growth and function of hepatocytes. Methods: HepG2, fetus and porcine hepatocytes were cultured. The viability, cell cycle and apoptosis, the leakage of LDH, AFP, total protein, glutathione and the changes on morphology of hepatocytes exposured to scP were investigated. Results: (1)Cultured in 10%, 30%, 50%, 100% scP for 24 h,the viability of HepG2 cells was inhibited (F=40. 108, P=0. 001). After 48 h, nearly all cells died except10% scP group. (2)Exposured to scP for 24 h,the percentage of S phase of the cell cycle was significantly increased and apoptosis was also significantly increased compared to control cultures. (3) The leakages of LDH were increased in the HepG2, fetus and porcine hepatocytes following exposure to scP for 5 h. (4)The synthesis of AFP in fetus and porcine hepatocytes were inhibited in medium containing 10% scP for 3d (t values were 8.1902, 5. 1034 separately, P<0. 01). Exposure of HepG2 cells to scP within 24 h resulted in a decrease in the total protein synthesis and a increase inthe GSH content. (5)Most of HepG2, fetus and porcine hepatocytes died in all except 10% scP groups after 24 h exposed to scP. Conclusion :scP can damage hepatocytes, which results from citric acid and sodium citrate contained in the fluid of blood maintenance.

  13. Relationship between metabolism and cytotoxicity of ortho-phenylphenol in isolated rat hepatocytes.

    Science.gov (United States)

    Nakagawa, Y; Tayama, S; Moore, G A; Moldéus, P

    1992-04-01

    The relationship between the metabolism and the cytotoxicity of ortho-phenylphenol (OPP) was investigated using isolated rat hepatocytes. Addition of OPP (0.5-1.0 mM) to the hepatocytes caused a dose-dependent toxicity; 1.0 mM OPP caused acute cell death. Pretreatment of hepatocytes with SKF-525A (50 microM, a non-toxic level) enhanced the cytotoxicity of OPP (0.5-1.0 mM). This was accompanied by inhibition of OPP metabolism. Conversely, OPP at low concentrations (0.5 or 0.75 mM) was converted sequentially to phenyl-hydroquinol (PHQ) and then to glutathione (GSH) conjugate in the cells. The concentrations of both metabolites, especially PHQ-GSH conjugate, were very low in hepatocytes exposed to 1.0 mM OPP alone as well as with SKF-525A. The cytotoxicity induced by 0.5 mM OPP was enhanced by the addition of diethylmaleate (1.25 mM) which continuously depletes cellular GSH. In contrast, additions to hepatocytes of 5 mM of dithiothreitol, cysteine, N-acetyl-L-cysteine or ascorbic acid significantly inhibited the cytotoxicity induced by 0.5 mM PHQ; GSH, protein thiols and ATP losses were also prevented. Further, these compounds depressed the rate of PHQ loss in hepatocyte suspensions. These results indicate that the acute cytotoxicity caused by the high dose (1.0 mM) of OPP is associated with direct action by the parent compound; at low doses (0.5-0.75 mM) of OPP, the prolonged depletion of GSH in hepatocytes enhances the cytotoxicity induced by PHQ.

  14. 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.

  15. Uptake of albumin nanoparticle surface modified with glycyrrhizin by primary cultured rat hepatocytes

    Institute of Scientific and Technical Information of China (English)

    Sheng-Jun Mao; Shi-Xiang Hou; Ru He; Liang-Ke Zhang; Da-Peng Wei; Yue-Qi Bi; Hui Jin

    2005-01-01

    AIM: To investigate the uptake difference between bovine serum albumin nanoparticle (BSA-NP) and bovine serum albumin nanoparticles with their surface modified byglycyrrhizin (BSA-NP-GL) and to develop a novel hepatocyte targeting BSA-NP-GL based on active targeting technology mediated by specific binding site of GL on rat cellular membrane. METHODS: Calcein loaded bovine serum albumin nanoparticles (Cal-BSA-NP) were prepared by desolvation process. Glycyrrhizin was conjugated to the surface reactive amino groups (SRAG) of Cal-BSA-NP by sodium periodate oxidization, which resulted in calcein-loaded bovine serum albumin nanoparticles with their surface modified by glycyrrhizin (Cal-BSA-NP-GL). The morphology of the two types of prepared nanoparticles (NP) was observed by transmission electron microscopy. The diameter of NP was measured with a laser particle size analyzer. The interaction between Cal-BSA-NP-GL and primary cultured hepatocytes was studied through cellular uptake experiments. The uptake amount of Cal-BSA-NPGL and Cal-BSA-NP by rat hepatocytes was determinedby fluorospectrophotometry. Uptake characteristics were investigated through experiments of competitive inhibition of specific binding site of GL. RESULTS: Both Cal-BSA-NP-GL and Cal-BSA-NP had regular spherical surfaces. The average diameter of CalBSA-NP-GL and Cal-BSA-NP was 77 and 79 nm respectively. The uptake amount of the two NP by hepatocytes reached its maximum at 2 h after incubation. The uptake amount of Cal-BSA-NP-GL by rat hepatocytes was 4.43-fold higher than that of Cal-BSA-NP. There was a significant difference in the uptake of Cal-BSA-NP-GL and Cal-BSA-NP by hepatocytes (P<0.01). The uptake of Cal-BSA-NP-GL was inhibited when GL was added previously to isolated rat hepatocytes, and the uptake of Cal-BSA-NP was not affected by GL.CONCLUSION: A binding site of GL is present on the surface of rat hepatocytes, BSA-NP-GL may be internalized via this site by hepatocytes and can be used as

  16. Inhibitors and pathways of hepatocytic protein degradation.

    Science.gov (United States)

    Seglen, P O; Gordon, P B; Grinde, B; Solheim, A; Kovács, A L; Poli, A

    1981-01-01

    On the basis of experiments using amino acids and various inhibitors (lysosomotropic amines, leupeptin, chymostatin, vanadate, vinblastine, anoxia, methylaminopurines), five different modes of endogenous protein degradation in isolated rat hepatocytes can be distinguished. The two non-lysosomal (amine-resistant) mechanisms preferentially degrade relatively labile (short-lived) proteins: one of these mechanisms is energy-dependent and chymostatin-sensitive, the other is not. Of the three lysosomal (amine-sensitive) mechanisms, one--quantitatively minor--is amino acid-resistant and preferentially degrades labile proteins. The two amino acid-sensitive mechanisms each seen account for about one-half of the degradation of relatively stable (long-lived) proteins; one of them is suppressed by leucine and apparently corresponds to the formation of electron microscopically visible autophagosomes; the other may represent a different type of autophagy, inhibited by asparagine and glutamine. A new class of inhibitors, the purine derivatives (methylated 6-aminopurines, and 6-mercaptopurines) appear to specifically suppress autophagic/lysosomal protein degradation, and may help to further elucidate the mechanisms of autophagy.

  17. Expression of CCR5 and c-Met in Breast Cancer and Its Significance%乳腺癌中CCR5和c-Met的表达及意义

    Institute of Scientific and Technical Information of China (English)

    张玉文; 王丹; 刘亚

    2014-01-01

    Objective To study the signiifcance of CCR5 and c-Met expression in breast cancer.Methods The expression of CCR5 and c-Met in 45 cases of breast cancer was analyzed by using immunohistochemisty. Results CCR5 was expressed in 55.6% of cancerous breast tissue (25/45), whereas it was only expressed in 8.9% of normal breast tissue (4/45). Signiifcant difference was noted between the expression levels (P<0.01). c-Met was expressed in 51% of cancerous breast tissue (23/45), but only 6.6% (3/45) of normal tissue. The observed difference in expression level of c-Met was also statistically signiifcant (P<0.01). On the other hand, 44.4% (20/45) of breast cancer patients with lymph node metastasis showed co-expression of both c-Met and CCR5, compared to 22.2% (10/45) in the normal breast tissue. Our ifndings demonstrate signiifcant associations between the expression of c-Met, CCR5 and lymph node metastasis in breast cancer patients. Conclusion CCR5 and c-Met expression was associated with poor prognosis of breast cancer patients, which could be predict the prognosis of breast cancer.%目的:探讨乳腺癌组织中CCR5和c-Met的表达及其意义。方法采用免疫组化SP法检测45例乳腺癌中CCR5和c-Met的表达。结果乳腺癌组织CCR5阳性率55.6%(25/45),正常乳腺组织中CCR5表达率8.9%(4/45),两种组织阳性表达率差异显著(P<0.01),c-Met的阳性表达率为51%(23/45),正常乳腺组织中c-Met表达率6.6%(3/45),两种组织阳性表达率差异显著(P<0.01)。在伴有淋巴结转移的乳腺癌中c-Met和CCR5的共同阳性率44.4%(20/45),无淋巴结转移的乳腺癌中阳性表达率为22.2%(10/45)。CCR5和c-Met的表达和乳腺癌的淋巴结转移成正相关。结论CCR5和c-Met与提示乳腺癌的转移预后因素有关,可作为预测乳腺癌转移的参考指标之一。

  18. Clinical applications of hepatocyte transplantation

    Institute of Scientific and Technical Information of China (English)

    Giada Pietrosi; Giovanni Battista Vizzini; Salvatore Gruttadauria; Bruno Gridelli

    2009-01-01

    The shortage of organ donors is a problem worldwide, with approximately 15% of adult patients with lifethreatening liver diseases dying while on the waiting list. The use of cell transplantation for liver disease is an attempt to correct metabolic defects, or to support liver function as a bridge to liver transplantation and, as such, has raised a number of expectations. Most of the available studies briefly reported here focus on adult hepatocyte transplantation (HT), and the results are neither reproducible nor comparable, because the means of infusion, amount of injected cells and clinical variability differ among the studies. To better understand the specific role of HT in the management of end-stage liver disease, it is important that controlled studies, designed on the principles of evidence-based medicine, be done in order to guarantee the reproducibility of results.

  19. Primary 3-dimensional culture of mouse hepatocytes

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Complex 3-dimensional structures with good functions have been obtained under the primary mixcoculture of mouse hepatocytes with mouse liver fibroblasts without serum. Albumin secretion is kept above 10 μg/106 cells and urea synthesis reaches 25 μg/106 on the 7th day of culture. Avoiding serum affection, liver fibroblasts' effects on hepatocytes' viability, functions and 3-dimensional structure forming in primary serum-free culture have been studied. Important effects of the mesenchyma, especially the direct adherence of fibroblasts to hepatocytes, are shown.

  20. Fenofibrate: metabolism and species differences for peroxisome proliferation in cultured hepatocytes.

    Science.gov (United States)

    Cornu-Chagnon, M C; Dupont, H; Edgar, A

    1995-06-01

    The hypolipidemic agent fenofibrate, which is a peroxisome proliferator in some rodents in vivo, was studied in cultured hepatocytes for its metabolism and effects on enzymatic induction related to peroxisome proliferation so as to lead to a better understanding of the mechanisms involved in peroxisome proliferation. [14C]-Fenofibrate was completely metabolized within 24 hr by primary cultures of rat hepatocytes and the metabolic pattern corresponded to that found in vivo. The main products were fenofibric acid and its glucuronidated form. Carbonyl reduction of fenofibric acid also occurred. The metabolic pattern of [14C]fenofibric acid was nearly the same as that of fenofibrate. Fenofibrate, fenofibric acid, and its reduced metabolite all induced peroxisomal (cyanide-insensitive) palmitoyl-CoA oxidation activity (PCOA) in rat hepatocytes, whereas derivatives lacking the carboxyl group were nearly inactive. The known species differences with respect to sensitivity to peroxisome proliferators in vivo was mirrored in cultured cells because fenofibric acid did not induce peroxisomal PCOA in primary culture of guinea pig hepatocytes nor in the human hepatoma cell line HepG2. The mechanistic association between the induction of CYP4A1-catalyzed lauric acid omega-hydroxylase (LAH) activity and peroxisomal PCOA induction was investigated. Fenofibric acid concomitantly induced LAH activity and peroxisomal PCOA in rat hepatocytes. Specific inhibition of LAH activity (-52%) by 10-undecynoic acid partially prevented induction of peroxisomal PCOA (-32%). The putative role of dicarboxylic acids, the oxidation product of omega-hydroxymonocarboxylic acids, in PCOA induction was further substantiated by the observed induction of peroxisomal PCOA by 1-12-dodecanedioic acid. We conclude that (1) fenofibric acid is the possible proximate peroxisome proliferator of fenofibrate in rat hepatocytes, (2) cultured hepatocytes reflect in vivo sensitivity to fenofibrate with respect to

  1. Sydnone SYD-1 affects the metabolic functions of isolated rat hepatocytes.

    Science.gov (United States)

    Brandt, Anna Paula; Pires, Amanda do Rocio Andrade; Rocha, Maria Eliane Merlin; Noleto, Guilhermina Rodrigues; Acco, Alexandra; de Souza, Carlos Eduardo Alves; Echevarria, Aurea; Canuto, André Vinícius dos Santos; Cadena, Sílvia Maria Suter Correia

    2014-07-25

    Previously, we demonstrated that sydnone SYD-1 (3-[4-chloro-3-nitrophenyl]-1,2,3-oxadiazolium-5-olate) impairs the mitochondrial functions linked to energy provision and suggested that this effect could be associated with its antitumor activity. Herein, we evaluated the effects of SYD-1 (25 and 50 μM) on rat hepatocytes to determine its cytotoxicity on non-tumor cells. SYD-1 (25 and 50 μM) did not affect the viability of hepatocytes in suspension after 1-40 min of incubation. However, the viability of the cultured hepatocytes was decreased by ∼66% as a consequence of treatment with SYD-1 (50 μM) for 18 h. Under the same conditions, SYD-1 promoted an increase in the release of LDH by ∼19%. The morphological changes in the cultured cells treated with SYD-1 (50 μM) were suggestive of cell distress, which was demonstrated by the presence of rounded hepatocytes, cell fragments and monolayer impairment. Furthermore, fluorescence microscopy showed an increase in the annexin label after treatment with SYD-1 (50 μM), suggesting that apoptosis had been induced in these cells. SYD-1 did not affect the states of respiration in the suspended hepatocytes, but the pyruvate levels were decreased by ∼36%, whereas the lactate levels were increased by ∼22% (for the 50 μM treatment). The basal and uncoupled states of respiration of the cultured hepatocytes were inhibited by ∼79% and ∼51%, respectively, by SYD-1 (50 μM). In these cells, SYD-1 (50 μM) increased the pyruvate and lactate levels by ∼84% and ∼16%, respectively. These results show that SYD-1 affects important metabolic functions related to energy provision in hepatocytes and that this effect was more pronounced on cells in culture than those in suspension.

  2. Role of hepatocyte nuclear factor 4α (HNF4α) in cell proliferation and cancer.

    Science.gov (United States)

    Walesky, Chad; Apte, Udayan

    2015-01-01

    Hepatocyte nuclear factor 4α (HNF4α) is an orphan nuclear receptor commonly known as the master regulator of hepatic differentiation, owing to the large number of hepatocyte-specific genes it regulates. Whereas the role of HNF4α in hepatocyte differentiation is well recognized and extensively studied, its role in regulation of cell proliferation is relatively less known. Recent studies have revealed that HNF4α inhibits proliferation not only of hepatocytes but also cells in colon and kidney. Further, a growing number of studies have demonstrated that inhibition or loss of HNF4α promotes tumorigenesis in the liver and colon, and reexpression of HNF4α results in decreased cancer growth. Studies using tissue-specific conditional knockout mice, knock-in studies, and combinatorial bioinformatics of RNA/ChIP-sequencing data indicate that the mechanisms of HNF4α-mediated inhibition of cell proliferation are multifold, involving epigenetic repression of promitogenic genes, significant cross talk with other cell cycle regulators including c-Myc and cyclin D1, and regulation of miRNAs. Furthermore, studies indicate that posttranslational modifications of HNF4α may change its activity and may be at the core of its dual role as a differentiation factor and repressor of proliferation. This review summarizes recent findings on the role of HNF4α in cell proliferation and highlights the newly understood function of this old receptor.

  3. Metformin protects rat hepatocytes against bile acid-induced apoptosis.

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    Titia E Woudenberg-Vrenken

    Full Text Available BACKGROUND: Metformin is used in the treatment of Diabetes Mellitus type II and improves liver function in patients with non-alcoholic fatty liver disease (NAFLD. Metformin activates AMP-activated protein kinase (AMPK, the cellular energy sensor that is sensitive to changes in the AMP/ATP-ratio. AMPK is an inhibitor of mammalian target of rapamycin (mTOR. Both AMPK and mTOR are able to modulate cell death. AIM: To evaluate the effects of metformin on hepatocyte cell death. METHODS: Apoptotic cell death was induced in primary rat hepatocytes using either the bile acid glycochenodeoxycholic acid (GCDCA or TNFα in combination with actinomycin D (actD. AMPK, mTOR and phosphoinositide-3 kinase (PI3K/Akt were inhibited using pharmacological inhibitors. Apoptosis and necrosis were quantified by caspase activation, acridine orange staining and Sytox green staining respectively. RESULTS: Metformin dose-dependently reduces GCDCA-induced apoptosis, even when added 2 hours after GCDCA, without increasing necrotic cell death. Metformin does not protect against TNFα/ActD-induced apoptosis. The protective effect of metformin is dependent on an intact PI3-kinase/Akt pathway, but does not require AMPK/mTOR-signaling. Metformin does not inhibit NF-κB activation. CONCLUSION: Metformin protects against bile acid-induced apoptosis and could be considered in the treatment of chronic liver diseases accompanied by inflammation.

  4. Control of IBMIR Induced by Fresh and Cryopreserved Hepatocytes by Low Molecular Weight Dextran Sulfate Versus Heparin.

    Science.gov (United States)

    Gustafson, Elisabet; Asif, Sana; Kozarcanin, Huda; Elgue, Graciela; Meurling, Staffan; Ekdahl, Kristina N; Nilsson, Bo

    2017-01-24

    Rapid destruction of hepatocytes after hepatocyte transplantation has hampered the application of this procedure clinically. The instant blood-mediated inflammatory reaction (IBMIR) is a plausible underlying cause for this cell loss. The present study was designed to evaluate the capacity of low molecular weight dextran sulfate (LMW-DS) to control these initial reactions from the innate immune system. Fresh and cryopreserved hepatocytes were tested in an in vitro whole-blood model using ABO-compatible blood. The ability to elicit IBMIR and the capacity of LMW-DS (100 μg/ml) to attenuate the degree of activation of the cascade systems were monitored. The effect was also compared to conventional anticoagulant therapy using unfractionated heparin (1 IU/ml). Both fresh and freeze-thawed hepatocytes elicited IBMIR to the same extent. LMW-DS reduced the platelet loss and maintained the cell counts at the same degree as unfractionated heparin, but controlled the coagulation and complement systems significantly more efficiently than heparin. LMW-DS also attenuated the IBMIR elicited by freeze-thawed cells. Therefore, LMW-DS inhibits the cascade systems and maintains the cell counts in blood triggered by both fresh and cryopreserved hepatocytes in direct contact with ABO-matched blood. LMW-DS at a previously used and clinically applicable concentration (100 μg/ml) inhibits IBMIR in vitro and is therefore a potential IBMIR inhibitor in hepatocyte transplantation.

  5. Selective insulin resistance in hepatocyte senescence

    Energy Technology Data Exchange (ETDEWEB)

    Aravinthan, Aloysious [Division of Gastroenterology and Hepatology, Department of Medicine, University of Cambridge, Cambridge (United Kingdom); Challis, Benjamin [Institute of Metabolic Sciences, University of Cambridge, Cambridge (United Kingdom); Shannon, Nicholas [Cancer Research UK Cambridge Institute, Cambridge (United Kingdom); Hoare, Matthew [Division of Gastroenterology and Hepatology, Department of Medicine, University of Cambridge, Cambridge (United Kingdom); Cancer Research UK Cambridge Institute, Cambridge (United Kingdom); Heaney, Judith [Division of Gastroenterology and Hepatology, Department of Medicine, University of Cambridge, Cambridge (United Kingdom); Foundation for Liver Research, Institute of Hepatology, London (United Kingdom); Alexander, Graeme J.M., E-mail: gja1000@doctors.org.uk [Division of Gastroenterology and Hepatology, Department of Medicine, University of Cambridge, Cambridge (United Kingdom)

    2015-02-01

    Insulin resistance has been described in association with chronic liver disease for decades. Hepatocyte senescence has been demonstrated in chronic liver disease and as many as 80% of hepatocytes show a senescent phenotype in advanced liver disease. The aim of this study was to understand the role of hepatocyte senescence in the development of insulin resistance. Senescence was induced in HepG2 cells via oxidative stress. The insulin metabolic pathway was studied in control and senescent cells following insulin stimulation. GLUT2 and GLUT4 expressions were studied in HepG2 cells and human liver tissue. Further, GLUT2 and GLUT4 expressions were studied in three independent chronic liver disease cohorts. Signalling impairment distal to Akt in phosphorylation of AS160 and FoxO1 was evident in senescent HepG2 cells. Persistent nuclear localisation of FoxO1 was demonstrated in senescent cells despite insulin stimulation. Increased GLUT4 and decreased GLUT2 expressions were evident in senescent cells, human cirrhotic liver tissue and publically available liver disease datasets. Changes in GLUT expressions were associated with a poor clinical prognosis. In conclusion, selective insulin resistance is evident in senescent HepG2 cells and changes in GLUT expressions can be used as surrogate markers of hepatocyte senescence. - Highlights: • Senescent hepatocytes demonstrate selective insulin resistance. • GLUT changes act as markers of hepatocyte senescence and have prognostic value. • Study offers insight into long noticed intimacy of cirrhosis and insulin resistance.

  6. Citotoxicity of Fipronil on Hepatocytes Isolated from Rat and Effects of Its Biotransformation

    Directory of Open Access Journals (Sweden)

    Marieli Guelfi

    2015-12-01

    Full Text Available ABSTRACT The aim of this study was to characterize the mechanism of toxicity of fipronil on hepatocytes isolated from the rat and the effect of its biotransformation on the toxicological potential. The toxicity of fipronil was assessed by monitoring the oxygen consumption and mitochondrial membrane potential, intracellular ATP concentration, Ca2+ homeostasis and cell viability. The cell viability was evaluated by trypan blue exclusion in hepatocytes that were isolated from the normal rats and by the release of the enzymes alanine transaminase and aspartate transaminase in hepatocytes that were isolated from the normal rats or proadifen-pretreated rats. Fipronil reduced mitochondrial respiration in the cells that were energized with glutamate plus malate in a dose-dependent manner and dissipated the mitochondrial membrane potential that was accompanied by a reduction in ATP concentration and a disruption of intracellular Ca2+ homeostasis. The cell viability was affected by fipronil with higher potency in hepatocytes that were isolated from the normal rats, which indicated that the metabolism of this insecticide increased its toxicological potential. The results of this study indicated that the toxicity of fipronil to the hepatocytes was related to the inhibition of mitochondrial activity, which led to decreased ATP synthesis and a consequent alteration in intracellular Ca2+ homeostasis and ultimately resulted in cell death.

  7. Regulation of ketogenesis during the suckling-weanling transition in the rat. Studies with isolated hepatocytes.

    Science.gov (United States)

    Benito, M; Whitelaw, E; Williamson, D H

    1979-04-15

    The rates of ketogenesis from endogenous substrates, butyrate or oleate, have been measured in isolated hepatocytes from suckling and weanling rats. Ketogenesis from endogenous substrate and from oleate decreased on weaning, whereas the rate from butyrate remained unchanged. It is concluded that the major site of regulation of ketogenesis during this period of development involves the disposal of long-chain fatty acyl-CoA between the esterification and beta-oxidation pathways. Modulators of lipogenesis [dihydroxyacetone and 5-(tetradecyloxy)-2-furoic acid] did not alter the rate of ketogenesis in hepatocytes from suckling rats, and it is suggested that this is due to the low rate of lipogenesis in these cells. Hepatocytes from fed weanling rats have a high rate of lipogenesis and evidence is presented for a reciprocal relationship between ketogenesis and lipogenesis, and ketogenesis, and esterification in these cells. Dibutyryl cyclic AMP stimulated ketogenesis from oleate in hepatocytes from fed weanling rats, even in the presence of an inhibitor of lipogenesis [5-(tetradecyloxy)-2-furoic acid], but not in cells from suckling rats. It is suggested that cyclic AMP may act via inhibition of esterification and that in hepatocytes from suckling rats ketogenesis is already maximally stimulated by the high basal concentrations of cyclic AMP [Beaudry, Chiasson & Exton (1977) Am. J. Physiol. 233, E175--E180].

  8. The biosynthesis of ascorbate protects isolated rat hepatocytes from cumene hydroperoxide-mediated oxidative stress.

    Science.gov (United States)

    Chan, Tom S; Shangari, Nandita; Wilson, John X; Chan, Helen; Butterworth, Roger F; O'Brien, Peter J

    2005-04-01

    Most animals synthesize ascorbate. It is an essential enzymatic cofactor for the synthesis of a variety of biological molecules and also a powerful antioxidant. There is, however, little direct evidence supporting an antioxidant role for endogenously produced ascorbate. Recently, we demonstrated that incubation of rat hepatocytes with 1-bromoheptane or phorone simultaneously depleted glutathione (GSH) and triggered rapid ascorbate synthesis. The present study investigates the hypothesis that endogenous ascorbate synthesis can confer protection against oxidative stress. Rat and guinea pig hepatocytes were depleted of GSH with 1-bromoheptane and subsequently treated with the oxidative stressor cumene hydroperoxide (CHP) in the presence or absence of the ascorbate synthesis inhibitor sorbinil. In rat hepatocytes, ascorbate content increased linearly (from 15.1 to 35.8 nmol/10(6) cells) over a 105-min incubation. Prior depletion of GSH increased CHP-induced cellular reactive oxygen species (ROS) production, lipid peroxidation, and cell death in rat and guinea pig hepatocytes. Inhibiting ascorbate synthesis, however, further elevated ROS production (2-fold), lipid peroxidation (1.5-fold), and cell death (2-fold) in rat hepatocytes only. This is the first time that endogenous ascorbate synthesis has been shown to decrease cellular susceptibility to oxidative stress. Protection by endogenously produced ascorbate may therefore need to be addressed when extrapolating data to humans from experiments using rodents capable of synthesizing ascorbate.

  9. The DNA replication licensing factor miniature chromosome maintenance 7 is essential for RNA splicing of epidermal growth factor receptor, c-Met, and platelet-derived growth factor receptor.

    Science.gov (United States)

    Chen, Zhang-Hui; Yu, Yan P; Michalopoulos, George; Nelson, Joel; Luo, Jian-Hua

    2015-01-16

    Miniature chromosome maintenance 7 (MCM7) is an essential component of DNA replication licensing complex. Recent studies indicate that MCM7 is amplified and overexpressed in a variety of human malignancies. In this report, we show that MCM7 binds SF3B3. The binding motif is located in the N terminus (amino acids 221-248) of MCM7. Knockdown of MCM7 or SF3B3 significantly increased unspliced RNA of epidermal growth factor receptor, platelet-derived growth factor receptor, and c-Met. A dramatic drop of reporter gene expression of the oxytocin exon 1-intron-exon 2-EGFP construct was also identified in SF3B3 and MCM7 knockdown PC3 and DU145 cells. The MCM7 or SF3B3 depleted cell extract failed to splice reporter RNA in in vitro RNA splicing analyses. Knockdown of SF3B3 and MCM7 leads to an increase of cell death of both PC3 and DU145 cells. Such cell death induction is partially rescued by expressing spliced c-Met. To our knowledge, this is the first report suggesting that MCM7 is a critical RNA splicing factor, thus giving significant new insight into the oncogenic activity of this protein.

  10. Directed random walks and constraint programming reveal active pathways in hepatocyte growth factor signaling.

    Science.gov (United States)

    Kittas, Aristotelis; Delobelle, Aurélien; Schmitt, Sabrina; Breuhahn, Kai; Guziolowski, Carito; Grabe, Niels

    2016-01-01

    An effective means to analyze mRNA expression data is to take advantage of established knowledge from pathway databases, using methods such as pathway-enrichment analyses. However, pathway databases are not case-specific and expression data could be used to infer gene-regulation patterns in the context of specific pathways. In addition, canonical pathways may not always describe the signaling mechanisms properly, because interactions can frequently occur between genes in different pathways. Relatively few methods have been proposed to date for generating and analyzing such networks, preserving the causality between gene interactions and reasoning over the qualitative logic of regulatory effects. We present an algorithm (MCWalk) integrated with a logic programming approach, to discover subgraphs in large-scale signaling networks by random walks in a fully automated pipeline. As an exemplary application, we uncover the signal transduction mechanisms in a gene interaction network describing hepatocyte growth factor-stimulated cell migration and proliferation from gene-expression measured with microarray and RT-qPCR using in-house perturbation experiments in a keratinocyte-fibroblast co-culture. The resulting subgraphs illustrate possible associations of hepatocyte growth factor receptor c-Met nodes, differentially expressed genes and cellular states. Using perturbation experiments and Answer Set programming, we are able to select those which are more consistent with the experimental data. We discover key regulator nodes by measuring the frequency with which they are traversed when connecting signaling between receptors and significantly regulated genes and predict their expression-shift consistently with the measured data. The Java implementation of MCWalk is publicly available under the MIT license at: https://bitbucket.org/akittas/biosubg.

  11. Conserved balance of hepatocyte nuclear DNA content in mononuclear and binuclear hepatocyte populations during the course of chronic viral hepatitis

    Institute of Scientific and Technical Information of China (English)

    Hidenori Toyoda; Takashi Kumada; Olivier Bregerie; Christian Brechot; Chantal Desdouets

    2006-01-01

    AIM: To analyze the percentages of hepatocytes with increased nuclear DNA content, i.e., tetraploid (4n) and octoploid (8n) nuclei, and then compared mononuclear and binuclear hepatocyte populations:METHODS: The percentages of mononuclear diploid(2n), 4n, and 8n hepatocytes and those of binuclear 2× 2n, 2 × 4n, and 2 × 8n hepatocytes were determined with a method that can simultaneously measure hepatocyte nuclear DNA content and binuclearity in 62patients with chronic hepatitis B or C. The percentage of 4n and 8n hepatocytes in the mononuclear hepatocyte population was compared with the percentage of 2 ×4n and 2 × 8n hepatocytes in the binuclear hepatocyte population.RESULTS: The percentages of 4n and 8n hepatocytes in mononuclear hepatocytes and 2 × 4n and 2 × 8n hepatocytes in binuclear hepatocytes were similar,regardless of the activity or fibrosis grade of chronic hepatitis and regardless of the infecting virus.CONCLUSION: The distribution of nuclear DNA content within mononuclear and binuclear hepatocyte populations was conserved during the course of chronic viral hepatitis.

  12. On the mechanism of metformin-inhibited hepatic gluconeogenesis

    Institute of Scientific and Technical Information of China (English)

    唐红菊

    2014-01-01

    Objective To investigate the underlying molecular mechanisms of metformin in inhibiting hepatic gluconeogenesis.Methods Primary hepatocytes of mice were isolated by a modified version of the collagenase method.The effect of metformin on glucose production in primary hepatocytes was detected by glucose oxidation method.The

  13. Transcriptome of extracellular vesicles released by hepatocytes.

    Directory of Open Access Journals (Sweden)

    Felix Royo

    Full Text Available The discovery that the cells communicate through emission of vesicles has opened new opportunities for better understanding of physiological and pathological mechanisms. This discovery also provides a novel source for non-invasive disease biomarker research. Our group has previously reported that hepatocytes release extracellular vesicles with protein content reflecting the cell-type of origin. Here, we show that the extracellular vesicles released by hepatocytes also carry RNA. We report the messenger RNA composition of extracellular vesicles released in two non-tumoral hepatic models: primary culture of rat hepatocytes and a progenitor cell line obtained from a mouse foetal liver. We describe different subpopulations of extracellular vesicles with different densities and protein and RNA content. We also show that the RNA cargo of extracellular vesicles released by primary hepatocytes can be transferred to rat liver stellate-like cells and promote their activation. Finally, we provide in vitro and in vivo evidence that liver-damaging drugs galactosamine, acetaminophen, and diclofenac modify the RNA content of these vesicles. To summarize, we show that the extracellular vesicles secreted by hepatocytes contain various RNAs. These vesicles, likely to be involved in the activation of stellate cells, might become a new source for non-invasive identification of the liver toxicity markers.

  14. Angiotensin II Induces C-Reactive Protein Expression via AT1-ROS-MAPK-NF-κB Signal Pathway in Hepatocytes

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    Jingjing Zhao

    2013-09-01

    Full Text Available Background: C-reactive protein (CRP participates in development of inflammatory diseases. Hepatocytes are a major contributor of circulating CRP. Although angiotensin II (Ang II is known to evoke inflammatory response, it remains unknown whether Ang II induces CRP expression in hepatocytes. The present study observed effect of Ang II on CRP expression and the related signal pathway in hepatocytes. Methods: mRNA and protein expressions in human hepatocytes were determined with RT-PCR and Western blot respectively. Reactive oxygen species (ROS was measured using a fluorescence probe. CRP in liver and serum of rats was determined by immunohistochemistry and ELISA respectively. Results: Ang II induced mRNA and protein expression of CRP in hepatocytes and increased CRP production in liver and CRP level in serum. Losartan reduced Ang II- induced CRP expression in hepatocytes. Losartan and thenoyltrifluoroacetone decreased Ang II-stimulated ROS production. N-acetylcysteine antagonized Ang II-induced CRP expression. Losartan and N-acetylcysteine inhibited Ang II-activated ERK1/2. Unlike ERK1/2, only losartan inhibited Ang II-activated JNK. Furthermore, pyrrolidine dithiocarbamate abolished Ang II-induced CRP expression. Conclusion: Ang II has ability to induce CRP expression in hepatocytes in vitro and in vivo through AT1 receptor followed by ROS, MAPK and NF-κB signal pathway.

  15. Cytotoxicity of ortho-phenylphenol in isolated rat hepatocytes.

    Science.gov (United States)

    Nakagawa, Y; Moldéus, P; Moore, G A

    1992-01-22

    The effects of ortho-phenylphenol (OPP) and its metabolites, phenyl-hydroquinol (PHQ) and phenyl-benzoquinone (PBQ), on isolated rat hepatocytes were investigated. Addition of OPP (0.5-1.0 mM) to cells caused a dose-dependent cell death accompanied by the depletion of intracellular levels of ATP, glutathione (GSH) and protein thiols. GSH loss correlated with the formation of oxidized GSH. In addition, PHQ and especially PBQ (both at 0.5 mM) resulted in acute cell death with rapid depletion of ATP, GSH and protein thiols, and further low doses of PBQ (10-50 microM) elicited serious impairment of mitochondrial functions related to oxidative phosphorylation and Ca fluxes in isolated liver mitochondria. These results indicate that mitochondria are a target for these compounds and that OPP is itself toxic to hepatocytes even when metabolism is inhibited. The loss of cellular GSH and protein thiols accompanied by the impairment of mitochondrial function may be the main mechanisms of cytotoxicity induced by OPP and its metabolites.

  16. Profile of hepatocyte apoptosis and bile lakes before and after bile duct decompression in severe obstructive jaundice patients

    Institute of Scientific and Technical Information of China (English)

    ToarJMLalisang; RadenSjamsuhidajat; NurjatiCSiregar; AkmalTaher

    2010-01-01

    BACKGROUND: Excessive hepatocyte apoptosis and bile lakes in severe obstructive jaundice might impair liver functions. Although decompression of the bile duct has been reported to improve liver functions in animal studies, the mechanism of obstruction differs from that in humans. This study aimed to determine the profiles of hepatocyte apoptosis and bile lakes following bile duct decompression in patients with severe obstructive jaundice in the clinical setting. METHODS: We conducted a "before and after study" on severe obstructive jaundice patients as a model of inhibition of the excessive process by bile duct decompression. Specimens of liver biopsies were taken before and after decompression of the bile duct and then stained by terminal deoxynucleotide transferase-mediated dUTP nick end-labeling (TUNEL) to identify hepatocyte apoptosis and by hematoxilin-eosin (HE) to identify bile lakes. All measurements were independently done by 2 observers. RESULTS: Twenty-one severe obstructive jaundice patients were included. In all patients, excessive hepatocyte apoptosis and bile lakes were apparent. After decompression, the hepatocyte apoptosis index decreased from 53.1 (SD 105) to 11.7 (SD 13.6) (P CONCLUSION: Bile duct decompression improves hepatocyte apoptosis and bile lakes in cases of severe obstructive jaundice, similar to the findings in animal studies.

  17. Cholangiocarcinomas can originate from hepatocytes in mice.

    Science.gov (United States)

    Fan, Biao; Malato, Yann; Calvisi, Diego F; Naqvi, Syed; Razumilava, Nataliya; Ribback, Silvia; Gores, Gregory J; Dombrowski, Frank; Evert, Matthias; Chen, Xin; Willenbring, Holger

    2012-08-01

    Intrahepatic cholangiocarcinomas (ICCs) are primary liver tumors with a poor prognosis. The development of effective therapies has been hampered by a limited understanding of the biology of ICCs. Although ICCs exhibit heterogeneity in location, histology, and marker expression, they are currently thought to derive invariably from the cells lining the bile ducts, biliary epithelial cells (BECs), or liver progenitor cells (LPCs). Despite lack of experimental evidence establishing BECs or LPCs as the origin of ICCs, other liver cell types have not been considered. Here we show that ICCs can originate from fully differentiated hepatocytes. Using a mouse model of hepatocyte fate tracing, we found that activated NOTCH and AKT signaling cooperate to convert normal hepatocytes into biliary cells that act as precursors of rapidly progressing, lethal ICCs. Our findings suggest a previously overlooked mechanism of human ICC formation that may be targetable for anti-ICC therapy.

  18. Resveratrol alters the lipid composition, metabolism and peroxide level in senescent rat hepatocytes.

    Science.gov (United States)

    Momchilova, Albena; Petkova, Diana; Staneva, Galya; Markovska, Tania; Pankov, Roumen; Skrobanska, Ralica; Nikolova-Karakashian, Mariana; Koumanov, Kamen

    2014-01-25

    Investigations were performed on the influence of resveratrol on the lipid composition, metabolism, fatty acid and peroxide level in plasma membranes of hepatocytes, isolated from aged rats. Hepatocytes were chosen due to the central role of the liver in lipid metabolism and homeostasis. The obtained results showed that the level of sphingomyelin (SM) and phosphatidylserine (PS) was augmented in plasma membranes of resveratrol-treated senescent hepatocytes. The saturated/unsaturated fatty acids ratio of the two most abundant membrane phospholipids, phosphatidylcholine (PC) and phosphatidylethanolamine (PE), was decreased as a result of resveratrol treatment. The neutral sphingomyelinase was found to be responsible for the increase of SM and the decrease of ceramide in plasma membranes of resveratrol-treated senescent hepatocytes. Using labeled acetate as a precursor of lipid synthesis we demonstrated, that resveratrol treatment resulted in inhibition mainly of phospholipid synthesis, followed by fatty acids synthesis. Resveratrol induced reduction of specific membrane-associated markers of apoptosis such as localization of PS in the external plasma membrane monolayer and ceramide level. Finally, the content of lipid peroxides was investigated, because the unsaturated fatty acids, which were augmented as a result of resveratrol treatment, are an excellent target of oxidative attack. The results showed that the lipid peroxide level was significantly lower, ROS were slightly reduced and GSH was almost unchanged in resveratrol-treated hepatocytes. We suggest, that one possible biochemical mechanism, underlying the reported resveratrol-induced changes, is the partial inactivation of neutral sphingomyelinase, leading to increase of SM, the latter acting as a native membrane antioxidant. In conclusion, our studies indicate that resveratrol treatment induces beneficial alterations in the phospholipid and fatty acid composition, as well as in the ceramide and peroxide

  19. Resveratrol differentially regulates NAMPT and SIRT1 in Hepatocarcinoma cells and primary human hepatocytes.

    Directory of Open Access Journals (Sweden)

    Susanne Schuster

    Full Text Available Resveratrol is reported to possess chemotherapeutic properties in several cancers. In this study, we wanted to investigate the molecular mechanisms of resveratrol-induced cell cycle arrest and apoptosis as well as the impact of resveratrol on NAMPT and SIRT1 protein function and asked whether there are differences in hepatocarcinoma cells (HepG2, Hep3B cells and non-cancerous primary human hepatocytes. We found a lower basal NAMPT mRNA and protein expression in hepatocarcinoma cells compared to primary hepatocytes. In contrast, SIRT1 was significantly higher expressed in hepatocarcinoma cells than in primary hepatocytes. Resveratrol induced cell cycle arrest in the S- and G2/M- phase and apoptosis was mediated by activation of p53 and caspase-3 in HepG2 cells. In contrast to primary hepatocytes, resveratrol treated HepG2 cells showed a reduction of NAMPT enzymatic activity and increased p53 acetylation (K382. Resveratrol induced NAMPT release from HepG2 cells which was associated with increased NAMPT mRNA expression. This effect was absent in primary hepatocytes where resveratrol was shown to function as NAMPT and SIRT1 activator. SIRT1 inhibition by EX527 resembled resveratrol effects on HepG2 cells. Furthermore, a SIRT1 overexpression significantly decreased both p53 hyperacetylation and resveratrol-induced NAMPT release as well as S-phase arrest in HepG2 cells. We could show that NAMPT and SIRT1 are differentially regulated by resveratrol in hepatocarcinoma cells and primary hepatocytes and that resveratrol did not act as a SIRT1 activator in hepatocarcinoma cells.

  20. Hepatocyte growth factor promotes proliferation, invasion, and metastasis of myeloid leukemia cells through PI3K-AKT and MAPK/ERK signaling pathway

    Science.gov (United States)

    Guo, Jiang-Rui; Li, Wei; Wu, Yong; Wu, Lin-Qing; Li, Xin; Guo, Ya-Fei; Zheng, Xiao-Hui; Lian, Xiao-Lan; Huang, Hui-Fang; Chen, Yuan-Zhong

    2016-01-01

    This study aims to investigate effects of HGF expression on biological behaviors of Kasumi-1 and HL60. Expression of HGF and c-Met gene were detected using qRT-PCR. Short hairpin RNA (shRNA) was used to reduce HGF expression. Silencing effect of shRNA was verified by qRT-PCR and western blot. Cell reproductive capacity, cell clonality and cell cycle (apoptosis) were detected by CCK-8, clone formation, flow cytometry (FCM), respectively. Cell adhesion, cell invasion ability and cell proliferation were also examined. Changes of PI3K-AKT, MAPK/ERK signaling factors were detected by western blot. HGF and c-Met expression in first-vist AML group was significantly higher than in AML-relief and normal control group. HGF shRNA can inhibit cell proliferation, inhibit cloning ability. Compared with control group, apoptosis ratios of Kasumi-1 and HL60 cell in interference groups were significantly higher. After shRNA interference, the number of adherent cells and transmembrane cells were significantly decreased compared with control group. Meanwhile, shRNA also down-regulated Bad, Bcl-XL, Bcl-2, CDK1, Cyclin B, MMP2, MMP9, and up-regulated cleaved caspase9, cleaved caspase3, cleaved PARP, Bax, and P21. Moreover, phosphorylated c-Met, AKT, Erk, and mTOR were also reduced. In conclusion, HGF and c-Met gene highly expressed among first-visit AML patients, but decreased after relief treatment. HGF may promote proliferation, invasion, and metastasis of AML cells through PI3K-AKT and MAPK/ERK signaling pathway. Therefore, proliferation and invasion ability of AML cell can be inhibited by down-regulating HGF gene to retardate cell in G2/M stage. PMID:27725846

  1. Hepatocyte expression of minichromosome maintenance protein-2 predicts fibrosis progression after transplantation for chronic hepatitis C virus: a pilot study.

    Science.gov (United States)

    Marshall, Aileen; Rushbrook, Simon; Morris, Lesley S; Scott, Ian S; Vowler, Sarah L; Davies, Susan E; Coleman, Nicholas; Alexander, Graeme

    2005-04-01

    Although graft infection with hepatitis C virus (HCV) occurs in virtually all patients transplanted for HCV-related liver disease, the outcome ranges from minimal disease to the rapid development of cirrhosis. Induction of hepatocyte cell cycle entry followed by inhibition of cell cycle progression has been proposed as a potential mechanism whereby HCV may cause hepatocyte dysfunction and may promote fibrogenesis. The aim of this study was to assess whether early hepatocyte cell cycle entry might predict subsequent fibrosis progression in patients with graft HCV infection after liver transplantation. Liver biopsies from 21 liver transplant recipients diagnostic of graft HCV infection but before development of significant fibrosis were studied. Patients were classed as nonprogressors, intermediate progressors, or rapid progressors according to the rate of fibrosis progression calculated from the most recent biopsy. Minichromosome maintenance protein 2 (Mcm-2), a highly sensitive and specific marker of cell cycle entry, and cyclin-dependent kinase inhibitor p21 were detected by immunohistochemistry. Hepatocyte Mcm-2 expression increased significantly according to rate of fibrosis. For nonprogressors, the median percentage of positive hepatocytes was 5.3% (range, 0.92%-11.2%) compared with 20.7% (4.6%-43.7%) in intermediate progressors and 23.7% (11.6%-55.2%) in rapid progressors (P = 0.002). By contrast, there was no evidence of a difference in hepatocyte p21 expression. Median values and ranges were 3.4% (range, 1.1%-30%), 13.3% (range, 1.4%-42.3%), and 11.8% (range, 7.6%-52.3%) for nonprogressors, intermediate progressors, and rapid progressors, respectively (P = 0.11). In conclusion, hepatocyte cell cycle entry may be important in the pathogenesis of posttransplant HCV hepatitis. Early assessment of hepatocyte Mcm-2 expression could help identify patients at high risk for progressive fibrosis before it occurs.

  2. Hepatocyte growth factor in lung repair and pulmonary fibrosis

    Institute of Scientific and Technical Information of China (English)

    Ronald Allan M PANGANIBAN; Regina M DAY

    2011-01-01

    Pulmonary remodeling is characterized by the permanent and progressive loss of the normal alveolar architecture, especially the loss of alveolar epithelial and endothelial cells, persistent proliferation of activated fibroblasts, or myoflbroblasts, and alteration of extracellular matrix. Hepatocyte growth factor (HGF) is a pleiotropic factor, which induces cellular motility, survival, proliferation, and morphogenesis, depending upon the cell type. In the adult, HGF has been demonstrated to play a critical role in tissue repair, including in the lung. Administration of HGF protein or ectopic expression of HGF has been demonstrated in animal models of pulmonary fibrosis to induce normal tissue repair and to prevent fibrotic remodeling. HGF-induced inhibition of fibrotic remodeling may occur via multiple direct and indirect mechanisms including the induction of cell survival and proliferation of pulmonary epithelial and endothelial cells, and the reduction of myofibroblast accumulation.

  3. Hepatocyte Growth Factor Reduces Free Cholesterol-Mediated Lipotoxicity in Primary Hepatocytes by Countering Oxidative Stress

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    Mayra Domínguez-Pérez

    2016-01-01

    Full Text Available Cholesterol overload in the liver has shown toxic effects by inducing the aggravation of nonalcoholic fatty liver disease to steatohepatitis and sensitizing to damage. Although the mechanism of damage is complex, it has been demonstrated that oxidative stress plays a prominent role in the process. In addition, we have proved that hepatocyte growth factor induces an antioxidant response in hepatic cells; in the present work we aimed to figure out the protective effect of this growth factor in hepatocytes overloaded with free cholesterol. Hepatocytes from mice fed with a high-cholesterol diet were treated or not with HGF, reactive oxygen species present in cholesterol overloaded hepatocytes significantly decreased, and this effect was particularly associated with the increase in glutathione and related enzymes, such as γ-gamma glutamyl cysteine synthetase, GSH peroxidase, and GSH-S-transferase. Our data clearly indicate that HGF displays an antioxidant response by inducing the glutathione-related protection system.

  4. Hepatocyte Growth Factor Reduces Free Cholesterol-Mediated Lipotoxicity in Primary Hepatocytes by Countering Oxidative Stress

    Science.gov (United States)

    Domínguez-Pérez, Mayra; Nuño-Lámbarri, Natalia; Clavijo-Cornejo, Denise; Luna-López, Armando; Souza, Verónica; Bucio, Leticia; Miranda, Roxana U.; Muñoz, Linda; Gomez-Quiroz, Luis Enrique; Uribe-Carvajal, Salvador; Gutiérrez-Ruiz, María Concepción

    2016-01-01

    Cholesterol overload in the liver has shown toxic effects by inducing the aggravation of nonalcoholic fatty liver disease to steatohepatitis and sensitizing to damage. Although the mechanism of damage is complex, it has been demonstrated that oxidative stress plays a prominent role in the process. In addition, we have proved that hepatocyte growth factor induces an antioxidant response in hepatic cells; in the present work we aimed to figure out the protective effect of this growth factor in hepatocytes overloaded with free cholesterol. Hepatocytes from mice fed with a high-cholesterol diet were treated or not with HGF, reactive oxygen species present in cholesterol overloaded hepatocytes significantly decreased, and this effect was particularly associated with the increase in glutathione and related enzymes, such as γ-gamma glutamyl cysteine synthetase, GSH peroxidase, and GSH-S-transferase. Our data clearly indicate that HGF displays an antioxidant response by inducing the glutathione-related protection system. PMID:27143995

  5. Constrained spheroids for prolonged hepatocyte culture.

    Science.gov (United States)

    Tong, Wen Hao; Fang, Yu; Yan, Jie; Hong, Xin; Hari Singh, Nisha; Wang, Shu Rui; Nugraha, Bramasta; Xia, Lei; Fong, Eliza Li Shan; Iliescu, Ciprian; Yu, Hanry

    2016-02-01

    Liver-specific functions in primary hepatocytes can be maintained over extended duration in vitro using spheroid culture. However, the undesired loss of cells over time is still a major unaddressed problem, which consequently generates large variations in downstream assays such as drug screening. In static culture, the turbulence generated by medium change can cause spheroids to detach from the culture substrate. Under perfusion, the momentum generated by Stokes force similarly results in spheroid detachment. To overcome this problem, we developed a Constrained Spheroids (CS) culture system that immobilizes spheroids between a glass coverslip and an ultra-thin porous Parylene C membrane, both surface-modified with poly(ethylene glycol) and galactose ligands for optimum spheroid formation and maintenance. In this configuration, cell loss was minimized even when perfusion was introduced. When compared to the standard collagen sandwich model, hepatocytes cultured as CS under perfusion exhibited significantly enhanced hepatocyte functions such as urea secretion, and CYP1A1 and CYP3A2 metabolic activity. We propose the use of the CS culture as an improved culture platform to current hepatocyte spheroid-based culture systems.

  6. Enhanced differentiation of embryonic stem cells using co-cultivation with hepatocytes.

    Science.gov (United States)

    Moore, Rebecca N; Dasgupta, Anouska; Rajaei, Nayyereh; Yarmush, Martin L; Toner, Mehmet; Larue, Lionel; Moghe, Prabhas V

    2008-12-15

    We examined the effects of co-cultivated hepatocytes on the hepatospecific differentiation of murine embryonic stem (ES) cells. Utilizing an established mouse ES cell line expressing high or low levels of E-cadherin, that we have previously shown to be responsive to hepatotrophic growth factor stimulation (Dasgupta et al., 2005. Biotechnol Bioeng 92(3):257-266), we compared co-cultures of cadherin-expressing ES (CE-ES) cells with cultured rat hepatocytes, allowing for either paracrine interactions (indirect co-cultures) or both juxtacrine and paracrine interactions (direct co-cultures, random and patterned). Hepatospecific differentiation of ES cells was evaluated in terms of hepatic-like cuboidal morphology, heightened gene expression of late maturation marker, glucose-6-phosphatase in relation to early marker, alpha-fetoprotein (AFP), and the intracellular localization of albumin. Hepatocytes co-cultured with growth factor primed CE-ES cells markedly enhanced ES cell differentiation toward the hepatic lineage, an effect that was reversed through E-cadherin blockage and inhibited in control ES cells with reduced cadherin expression. Comparison of single ES cell cultures versus co-cultures show that direct contact co-cultures of hepatocytes and CE-ES cells maximally promoted ES cell commitment towards hepatodifferentiation, suggesting cooperative effects of cadherin-based juxtacrine and paracrine interactions. In contrast, E-cadherin deficient mouse ES (CD-ES) cells co-cultured with hepatocytes failed to show increased G6P expression, confirming the role of E-cadherin expression. To establish whether albumin expression in CE-ES cells was spatially regulated by co-cultured hepatocytes, we co-cultivated CE-ES cells around micropatterned, pre-differentiated rat hepatocytes. Albumin localization was enhanced "globally" within CE-ES cell colonies and was inhibited through E-cadherin antibody blockage in all but an interfacial band of ES cells. Thus, stem cell based

  7. Rifampicin does not significantly affect the expression of Small heterodimer partner (SHP in primary human hepatocytes

    Directory of Open Access Journals (Sweden)

    Petr ePavek

    2012-01-01

    Full Text Available The small/short heterodimer partner (SHP, NR0B2 is a nuclear receptor corepressor lacking a DNA binding domain. SHP is induced by bile acid-activated farnesoid X receptor (FXR resulting in CYP7A1 gene suppression. In contrast, Pregnane X receptor (PXR activation by its ligands was recently suggested to inhibit SHP gene transactivation to maximize the induction of PXR target genes. However, there are also conflicting reports in literature whether PXR or rodent Pxr activation down-regulates SHP/Shp expression. Moreover, the PXR-mediated regulation of the SHP gene has been studied only at the SHP mRNA and transactivation (gene reporter assay levels.In this study, we studied the effect of rifampicin, a prototype PXR ligand, on SHP mRNA and protein expression in three primary human hepatocyte cultures.We found that SHP mRNA is not systematically down-regulated in hepatocyte in culture after 24 h treatment with rifampicin. Consistently, we did not observe down-regulation of SHP protein in primary human hepatocytes after 24 and 48 h of incubation with rifampicin.We can conclude that although we observed slight down-regulation of SHP mRNA and protein in several hepatocyte preparations, the phenomenon is unlikely critical for PXR-mediated induction of its target genes.

  8. Ammonia-induced energy disorders interfere with bilirubin metabolism in hepatocytes.

    Science.gov (United States)

    Wang, Qiongye; Wang, Yanfang; Yu, Zujiang; Li, Duolu; Jia, Bin; Li, Jingjing; Guan, Kelei; Zhou, Yubing; Chen, Yanling; Kan, Quancheng

    2014-08-01

    Hyperammonemia and jaundice are the most common clinical symptoms of hepatic failure. Decreasing the level of ammonia in the blood is often accompanied by a reduction in bilirubin in patients with hepatic failure. Previous studies have shown that hyperammonemia can cause bilirubin metabolism disorders, however it is unclear exactly how hyperammonemia interferes with bilirubin metabolism in hepatocytes. The purpose of the current study was to determine the mechanism or mechanisms by which hyperammonemia interferes with bilirubin metabolism in hepatocytes. Cell viability and apoptosis were analyzed in primary hepatocytes that had been exposed to ammonium chloride. Mitochondrial morphology and permeability were observed and analyzed, intermediates of the tricarboxylic acid (TCA) cycle were determined and changes in the expression of enzymes related to bilirubin metabolism were analyzed after ammonia exposure. Hyperammonemia inhibited cell growth, induced apoptosis, damaged the mitochondria and hindered the TCA cycle in hepatocytes. This led to a reduction in energy synthesis, eventually affecting the expression of enzymes related to bilirubin metabolism, which then caused further problems with bilirubin metabolism. These effects were significant, but could be reversed with the addition of adenosine triphosphate (ATP). This study demonstrates that ammonia can cause problems with bilirubin metabolism by interfering with energy synthesis.

  9. Intracytoplasmic triglyceride accumulation produced by dexamethasone in adult rat hepatocytes cultivated on 3T3 cells.

    Science.gov (United States)

    Mendoza-Figueroa, T; Hernandez, A; De Lourdes Lopez, M; Kuri-Harcuch, W

    1988-11-30

    Glucocorticoids, such as hydrocortisone (HC) and dexamethasone (DEX), when administered to rats, induce lipid accumulation within hepatocytes (fatty liver). To investigate whether glucocorticoids can produce triglyceride (TG) accumulation as they do in vivo and the involved mechanisms, we have used primary cultures of rat hepatocytes which synthesized and secrete triglycerides into the culture medium. Hepatocytes cultivated on a feeder layer of lethally treated 3T3 cells were exposed for 2 weeks to micromolar concentrations of DEX. This glucocorticoid caused morphological alterations and cells accumulated lipid droplets in their cytoplasm; the TG content increased up to 6-fold in a concentration- and time-dependent manner. The removal of [14C]acetic or [14C]oleic acid from the culture medium was not altered in the cultures treated with 50 micrograms/ml DEX but the incorporation of [14C]acetic and [14C]oleic acid into TG in these cultures was about 13-fold and 60% higher than in non-treated cells, respectively. On the other hand, hepatocytes treated with 50 micrograms/ml DEX for 2 weeks showed a 16-fold decrease in TG release and 40% inhibition in protein export, whereas synthesis of total cellular proteins was not altered. Our results show that corticosteroids, such as DEX, caused lipid accumulation in liver cells through an increased synthesis and/or esterification of fatty acids, but mostly through a decrease in the secretion of TG.

  10. Recruitment of stem cells by hepatocyte growth factor via intracoronary gene transfection in the postinfarction heart failure

    Institute of Scientific and Technical Information of China (English)

    YANG; ZhiJian; WANG; Wei; MA; DongChao; ZHANG; YouRong; WANG; LianSheng; ZHANG; YuQing; XU; ShunLin; CHEN; Bo; MIAO; DengShun; CAO; KeJiang

    2007-01-01

    We aim to study the amelioration effect of adenovirus5-mediated human hepatocyte growth factor gene transfer on postinfarction heart failure in swine model. Twelve Suzhong young swine were randomly divided into 2 groups of 6 pigs each: Ad5-HGF group and mock-vector Ad5 group. Four weeks after ligation of the left anterior descending coronary artery, Ad5-HGF was intracoronarily transferred into the myocardium. Simultaneously, gate cardiac perfusion imaging was performed to evaluate the heart function. Three weeks later, gate cardiac perfusion imaging was performed again, then the hearts were removed and sectioned for immunohistochemical examination to illustrate the effects of Ad5-HGF on infarcted myocardium. The expression of HGF was examined by ELISA. The results were: (1) compared with the mock-vector Ad5 group, high expression of human HGF was observed in the myocardium of Ad5-HGF group; (2) in the Ad5-HGF group, the number of CD117+ cells co-expressing c-Met per mm2 was significantly larger; (3) the improvement in LVEF was greater in the Ad5-HGF group than in the mock-vector Ad5 group. We concluded that: (1) high expression of human HGF was observed in the myocardium through intracoronary gene transfection; (2) HGF can improve the mobilization of CD117+/c-Met+ stem cells into ischemic myocardium. The amelioration effect of HGF on postinfarction heart failure could not be limited to stimulating angiogenesis, anti-apoptosis, anti-fibrosis, but was also involved in the recruitment of stem cells into myocardium.

  11. Species-specific interaction of HIV protease inhibitors with accumulation of cholyl-glycylamido-fluorescein (CGamF) in sandwich-cultured hepatocytes.

    Science.gov (United States)

    Ye, Zhi-wei; Van Pelt, Jos; Camus, Sandrine; Snoeys, Jan; Augustijns, Patrick; Annaert, Pieter

    2010-06-01

    Using sandwich-cultured hepatocytes from rat, dog, pig, and human, we investigated the species-specificity of interaction of HIV protease inhibitors (PI) with in vitro hepatic accumulation of the bile salt analogue cholyl-glycylamido-fluorescein (CGamF). Extracellular sodium depletion or coincubation with the OATP/Oatp inhibitors rifampicin and digoxin revealed that about 35% of active CGamF accumulation was mediated by Ntcp/NTCP in rat and human hepatocytes, while the contribution of this sodium-dependent transporter reached 50-60% in dog and pig hepatocytes. One or more sodium-independent transporters, likely belonging to the Oatp/OATP family, constitute a major transport mechanism for CGamF accumulation. Various HIV PI (0.5, 5, 25 microM) exhibited pronounced species differences in their interaction with active CGamF accumulation (1 microM), although some similarity was observed between the dog and human interaction profiles when HIV PI were tested at 0.5 microM. Atazanavir, indinavir, and darunavir were the most potent inhibitors of CGamF accumulation in human hepatocytes. Potent inhibition of CGamF accumulation by ritonavir in rat hepatocytes contrasted with a weak effect in human hepatocytes. Thorough characterization of in vitro disposition of probe substrates in preclinical species compared to human hepatocytes will ultimately support a better insight in species-specific mechanisms underlying drug interactions and drug-mediated toxicity.

  12. Fipronil induces CYP isoforms and cytotoxicity in human hepatocytes.

    Science.gov (United States)

    Das, Parikshit C; Cao, Yan; Cherrington, Nathan; Hodgson, Ernest; Rose, Randy L

    2006-12-15

    Recent studies have demonstrated the potential of pesticides to either inhibit or induce xenobiotic metabolizing enzymes in humans. Exposure of human hepatocytes to doses of fipronil (5-amino-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-4-[(trifluoromethyl) sulfinyl]-1H-pyrazole-3-carbonitrile) ranging from 0.1 to 25 microM resulted in a dose dependent increase in CYP1A1 mRNA expression (3.5 to approximately 55-fold) as measured by the branched DNA assay. In a similar manner, CYP3A4 mRNA expression was also induced (10-30-fold), although at the higher doses induction returned to near control levels. CYP2B6 and 3A5 were also induced by fipronil, although at lower levels (2-3-fold). Confirmation of bDNA results were sought through western blotting and/or enzyme activity assays. Western blots using CYP3A4 antibody demonstrated a dose responsive increase from 0.5 to 1 microM followed by decreasing responses at higher concentrations. Similar increases and decreases were observed in CYP3A4-specific activity levels as measured using 6beta-hydroxytestosterone formation following incubation with testosterone. Likewise, activity levels for a CYP1A1-specific substrate, luciferin CEE, demonstrated that CYP1A1 enzyme activities were maximally induced by 1 microM fipronil followed by dramatically declining activity measurements at 10 and 25 microM. Cytotoxic effects of fipronil and fipronil sulfone were examined using the adenylate kinase and the trypan blue exclusion assays in HepG2 cells and human hepatocytes. The results indicate both that HepG2 cells and primary human hepatocytes are sensitive to the cytotoxic effects of fipronil. The maximum induction of adenylate kinase was ca. 3-fold greater than the respective controls in HepG2 and 6-10-fold in the case of primary hepatocytes. A significant time- and dose-dependent induction of adenylate kinase activity in HepG2 cells was noted from 0.1 to 12.5 microM fipronil followed by decreasing activities at 25 and 50 microM. For

  13. Duck hepatitis B virus covalently closed circular DNA appears to survive hepatocyte mitosis in the growing liver

    Energy Technology Data Exchange (ETDEWEB)

    Reaiche-Miller, Georget Y.; Thorpe, Michael; Low, Huey Chi; Qiao, Qiao; Scougall, Catherine A. [School of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA 5005 (Australia); Mason, William S.; Litwin, Samuel [Institute for Cancer Research, Fox Chase Cancer Center, Philadelphia, PA 19111 (United States); Jilbert, Allison R., E-mail: allison.jilbert@adelaide.edu.au [School of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA 5005 (Australia)

    2013-11-15

    Nucleos(t)ide analogues that inhibit hepatitis B virus (HBV) DNA replication are typically used as monotherapy for chronically infected patients. Treatment with a nucleos(t)ide analogue eliminates most HBV DNA replication intermediates and produces a gradual decline in levels of covalently closed circular DNA (cccDNA), the template for viral RNA synthesis. It remains uncertain if levels of cccDNA decline primarily through hepatocyte death, or if loss also occurs during hepatocyte mitosis. To determine if cccDNA survives mitosis, growing ducklings infected with duck hepatitis B virus (DHBV) were treated with the nucleoside analogue, Entecavir. Viremia was suppressed at least 10{sup 5}-fold, during a period when average liver mass increased 23-fold. Analysis of the data suggested that if cccDNA synthesis was completely inhibited, at least 49% of cccDNA survived hepatocyte mitosis. However, there was a large duck-to-duck variation in cccDNA levels, suggesting that low level cccDNA synthesis may contribute to this apparent survival through mitosis. - Highlights: • The hepatitis B virus nuclear template is covalently closed circular DNA (cccDNA). • cccDNA was studied during liver growth in duck hepatitis B virus infected ducks. • Virus DNA replication and new cccDNA synthesis were inhibited with Entecavir. • At least 49% of cccDNA appeared to survive hepatocyte mitosis. • Low level virus DNA synthesis may contribute to survival of cccDNA through mitosis.

  14. Stathmin mediates hepatocyte resistance to death from oxidative stress by down regulating JNK.

    Science.gov (United States)

    Zhao, Enpeng; Amir, Muhammad; Lin, Yu; Czaja, Mark J

    2014-01-01

    Stathmin 1 performs a critical function in cell proliferation by regulating microtubule polymerization. This proliferative function is thought to explain the frequent overexpression of stathmin in human cancer and its correlation with a bad prognosis. Whether stathmin also functions in cell death pathways is unclear. Stathmin regulates microtubules in part by binding free tubulin, a process inhibited by stathmin phosphorylation from kinases including c-Jun N-terminal kinase (JNK). The involvement of JNK activation both in stathmin phosphorylation, and in hepatocellular resistance to oxidative stress, led to an examination of the role of stathmin/JNK crosstalk in oxidant-induced hepatocyte death. Oxidative stress from menadione-generated superoxide induced JNK-dependent stathmin phosphorylation at Ser-16, Ser-25 and Ser-38 in hepatocytes. A stathmin knockdown sensitized hepatocytes to both apoptotic and necrotic cell death from menadione without altering levels of oxidant generation. The absence of stathmin during oxidative stress led to JNK overactivation that was the mechanism of cell death as a concomitant knockdown of JNK1 or JNK2 blocked death. Hepatocyte death from JNK overactivation was mediated by the effects of JNK on mitochondria. Mitochondrial outer membrane permeabilization occurred in stathmin knockdown cells at low concentrations of menadione that triggered apoptosis, whereas mitochondrial β-oxidation and ATP homeostasis were compromised at higher, necrotic menadione concentrations. Stathmin therefore mediates hepatocyte resistance to death from oxidative stress by down regulating JNK and maintaining mitochondrial integrity. These findings demonstrate a new mechanism by which stathmin promotes cell survival and potentially tumor growth.

  15. Stathmin mediates hepatocyte resistance to death from oxidative stress by down regulating JNK.

    Directory of Open Access Journals (Sweden)

    Enpeng Zhao

    Full Text Available Stathmin 1 performs a critical function in cell proliferation by regulating microtubule polymerization. This proliferative function is thought to explain the frequent overexpression of stathmin in human cancer and its correlation with a bad prognosis. Whether stathmin also functions in cell death pathways is unclear. Stathmin regulates microtubules in part by binding free tubulin, a process inhibited by stathmin phosphorylation from kinases including c-Jun N-terminal kinase (JNK. The involvement of JNK activation both in stathmin phosphorylation, and in hepatocellular resistance to oxidative stress, led to an examination of the role of stathmin/JNK crosstalk in oxidant-induced hepatocyte death. Oxidative stress from menadione-generated superoxide induced JNK-dependent stathmin phosphorylation at Ser-16, Ser-25 and Ser-38 in hepatocytes. A stathmin knockdown sensitized hepatocytes to both apoptotic and necrotic cell death from menadione without altering levels of oxidant generation. The absence of stathmin during oxidative stress led to JNK overactivation that was the mechanism of cell death as a concomitant knockdown of JNK1 or JNK2 blocked death. Hepatocyte death from JNK overactivation was mediated by the effects of JNK on mitochondria. Mitochondrial outer membrane permeabilization occurred in stathmin knockdown cells at low concentrations of menadione that triggered apoptosis, whereas mitochondrial β-oxidation and ATP homeostasis were compromised at higher, necrotic menadione concentrations. Stathmin therefore mediates hepatocyte resistance to death from oxidative stress by down regulating JNK and maintaining mitochondrial integrity. These findings demonstrate a new mechanism by which stathmin promotes cell survival and potentially tumor growth.

  16. Impaired mitochondrial functions contribute to 3-bromopyruvate toxicity in primary rat and mouse hepatocytes.

    Science.gov (United States)

    Sobotka, Ondřej; Endlicher, René; Drahota, Zdeněk; Kučera, Otto; Rychtrmoc, David; Raad, Marjan; Hakeem, Khurum; Červinková, Zuzana

    2016-08-01

    A compound with promising anticancer properties, 3-bromopyruvate (3-BP) is a synthetic derivative of a pyruvate molecule; however, its toxicity in non-malignant cells has not yet been fully elucidated. Therefore, we elected to study the effects of 3-BP on primary hepatocytes in monolayer cultures, permeabilized hepatocytes and isolated mitochondria. After a 1-h treatment with 100 μM 3-BP cell viability of rat hepatocytes was decreased by 30 % as measured by the WST-1 test (p < 0.001); after 3-h exposure to ≥200 μM 3-BP lactate dehydrogenase leakage was increased (p < 0.001). Reactive oxygen species production was increased in the cell cultures after a 1-h treatment at concentrations ≥100 μmol/l (p < 0.01), and caspase 3 activity was increased after a 20-h incubation with 150 μM and 200 μM 3-BP (p < 0.001). This toxic effect of 3-BP was also proved using primary mouse hepatocytes. In isolated mitochondria, 3-BP induced a dose- and time-dependent decrease of mitochondrial membrane potential during a 10-min incubation both with Complex I substrates glutamate + malate or Complex II substrate succinate, although this decrease was more pronounced with the latter. We also measured the effect of 3-BP on respiration of isolated mitochondria. ADP-activated respiration was inhibited by 20 μM 3-BP within 10 min. Similar effects were also found in permeabilized hepatocytes of both species.

  17. Biotransformation and cytotoxic effects of hydroxychavicol, an intermediate of safrole metabolism, in isolated rat hepatocytes.

    Science.gov (United States)

    Nakagawa, Yoshio; Suzuki, Toshinari; Nakajima, Kazuo; Ishii, Hidemi; Ogata, Akio

    2009-06-15

    The biotransformation and cytotoxic effects of hydroxychavicol (HC; 1-allyl-3,4-dihydroxybenzene), which is a catecholic component in piper betel leaf and a major intermediary metabolite of safrole in rats and humans, was studied in freshly isolated rat hepatocytes. The exposure of hepatocytes to HC caused not only concentration (0.25-1.0mM)- and time (0-3h)-dependent cell death accompanied by the loss of cellular ATP, adenine nucleotide pools, reduced glutathione, and protein thiols, but also the accumulation of glutathione disulfide and malondialdehyde, indicating lipid peroxidation. At a concentration of 1mM, the cytotoxic effects of safrole were less than those of HC. The loss of mitochondrial membrane potential and generation of oxygen radical species assayed using 2',7'-dichlorodihydrofluoresein diacetate (DCFH-DA) in hepatocytes treated with HC were greater than those with safrole. HC at a weakly toxic level (0.25 and/or 0.50mM) was metabolized to monoglucuronide, monosulfate, and monoglutathione conjugates, which were identified by mass spectra and/or (1)H nuclear magnetic resonance spectra. The amounts of sulfate rather than glucuronide or glutathione conjugate predominantly increased, accompanied by a loss of the parent compound, with time. In hepatocytes pretreated with either diethyl maleate or salicylamide, HC-induced cytotoxicity was enhanced, accompanied by a decrease in the formation of these conjugates and by the inhibition of HC loss. Taken collectively, our results indicate that (a) mitochondria are target organelles for HC, which elicits cytotoxicity through mitochondrial failure related to mitochondrial membrane potential at an early stage and subsequently lipid peroxidation through oxidative stress at a later stage; (b) the onset of cytotoxicity depends on the initial and residual concentrations of HC rather than those of its metabolites; (c) the toxicity of HC is greater than that of safrole, suggesting the participation of a catecholic

  18. Experimental hepatocyte xenotransplantation--a comprehensive review of the literature.

    Science.gov (United States)

    Zhou, Huidong; Liu, Hong; Ezzelarab, Mohamed; Schmelzer, Eva; Wang, Yi; Gerlach, Jörg; Gridelli, Bruno; Cooper, David K C

    2015-01-01

    Hepatocyte transplantation (Tx) is a potential therapy for certain diseases of the liver, including hepatic failure. However, there is a limited supply of human livers as a source of cells and, after isolation, human hepatocytes can be difficult to expand in culture, limiting the number available for Tx. Hepatocytes from other species, for example, the pig, have therefore emerged as a potential alternative source. We searched the literature through the end of 2014 to assess the current status of experimental research into hepatocyte xenoTx. The literature search identified 51 reports of in vivo cross-species Tx of hepatocytes in a variety of experimental models. Most studies investigated the Tx of human (n = 23) or pig (n = 19) hepatocytes. No studies explored hepatocytes from genetically engineered pigs. The spleen was the most common site of Tx (n = 23), followed by the liver (through the portal vein [n = 6]) and peritoneal cavity (n = 19). In 47 studies (92%), there was evidence of hepatocyte engraftment and function across a species barrier. The data provided by this literature search strengthen the hypothesis that xenoTx of hepatocytes is feasible and potentially successful as a clinical therapy for certain liver diseases, including hepatic failure. By excluding vascular structures, hepatocytes isolated from genetically engineered pig livers may address some of the immunological problems of xenoTx.

  19. Determination of a novel anticancer c-Met inhibitor LS-177 in rat plasma and tissues with a validated UPLC-MS/MS method: application to pharmacokinetics and tissue distribution study.

    Science.gov (United States)

    Ju, Ping; Liu, Zhenzhen; Jiang, Yu; Zhao, Simin; Zhang, Lunhui; Zhang, Yuanyuan; Gu, Liqiang; Tang, Xing; Bi, Kaishun; Chen, Xiaohui

    2015-07-01

    LS-177 is a novel small-molecule kinase inhibitor employed to interrupt the c-Met signaling pathway. A rapid and sensitive ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for determination of LS-177 in rat plasma and tissues. The biosamples were extracted by liquid-liquid extraction with methyl tert-butyl ether and separated on a C18 column (50 × 4.6 mm, 2.6 µm) using a gradient elution mobile phase consisting of acetonitrile-0.1% formic acid water. Under the optimal conditions, the selectivity of the method was satisfactory with no endogenous interference. The intraday and interday precisions (relative standard deviation) were LS-177 was stable during the preparation and analytical processes. The UPLC-MS/MS method was successfully applied to pharmacokinetic and tissue distribution studies. The results indicated that there was no significant drug accumulation after multiple-dose oral administration of LS-177. The tissue distribution study exhibited significant higher uptakes of LS-177 in stomach, intestine, lung and liver among all of the tissues. The results in pharmacokinetics and tissue distribution may provide a meaningful basis for clinical application.

  20. 乳腺浸润性导管癌患者癌组织c-Met蛋白的表达及病理探讨%C-Met protein expression of cancer tissue of patients with breast inifltrating ductal carcinoma and its pathological study

    Institute of Scientific and Technical Information of China (English)

    王晓娟

    2016-01-01

    Objective to analyze and investigate c-Met protein expression of cancer tissue of patients with breast infiltrating ductal carcinoma and its pathological significance.Methods randomly choose clinical pathological specimens of 140 patients with breast infiltrating ductal carcinoma in our hospital from January 2015 to December 2015 as research objects, detect c-met protein expression of breast cancer tissue, and analyze relations between c-Met protein expression and TNM staging, tumor pathological grading, lymph node metastasis and tumor size.Results there were 60 cases positive c-Met protein, accounting for 42.86%; 80 cases negative c-Met protein, accounting for 57.14%. C-met protein expression positive rate in pathological grade I, II, and III and different tumor sizes showed no significant difference (P> 0.05); expression positive rate at TNM stage III to IV and breast cancer tissue with lymph node metastasis was significantly higher than that in TNM stage I-II and breast cancer tissue without lymph node metastasis, and data difference showed statistical significance (P0.05);在TNM分期III~IV期及有淋巴结转移的乳腺癌组织中表达阳性率明显高于TNM分期I~II期无淋巴转移的乳腺癌组织,且数据均差异有统计学意义(P<0.05)。结论 c-Met蛋白的表达在乳腺癌的转移以及侵袭中具有不可忽视的作用,可以采用干预手段或者是检测c-Met蛋白表达来进行对乳腺癌其发生、发展情况和患者的预后做判断。

  1. Hepatocyte xenotransplantation for treating liver disease.

    Science.gov (United States)

    Bonavita, André Gustavo; Quaresma, Kátia; Cotta-de-Almeida, Vinícius; Pinto, Marcelo Alves; Saraiva, Roberto Magalhães; Alves, Luiz Anastácio

    2010-01-01

    The treatment of acute and chronic liver failure is still a challenge despite modern therapeutic innovations. While liver transplantation can restore liver function and improve patient survival, donor shortages limit this treatment to a small number of patients. Cellular xenotransplantation has emerged as an alternative for treating liver failure. Xenohepatocytes could be readily available in sufficient quantities to treat patients in critical condition and thereby reduce the donor shortage. The use of isolated encapsulated or non-encapsulated cells can reduce the immunorejection response. Several studies using animal models of acute or chronic liver failure have demonstrated improved survival and recovery of liver function after xenotransplantation of adult hepatocytes. Porcine liver cells are a potential source of xenohepatocytes due to similarities with human physiology and the great number of hepatocytes that can be obtained. The recent development of less immunogenic transgenic pigs, new immunosuppressive drugs, and cellular encapsulation systems represents important advances in the field of cellular xenotransplantation. In this study, we review the work carried out in animal models that deals with the advantages and limitations of hepatocyte xenotransplantation, and we propose new studies needed in this field.

  2. Hepatitis C virus (HCV) and hepatitis B virus (HBV) can coinfect the same hepatocyte in the liver of patients with chronic HCV and occult HBV infection.

    Science.gov (United States)

    Rodríguez-Iñigo, E; Bartolomé, J; Ortiz-Movilla, N; Platero, C; López-Alcorocho, J M; Pardo, M; Castillo, I; Carreño, V

    2005-12-01

    In this work, we have shown that hepatitis C virus (HCV) and hepatitis B virus (HBV) can coexist in the same hepatocyte using double fluorescent in situ hybridization in liver biopsy samples from patients with chronic HCV infection with occult HBV infection. Digital image analysis of hybridization signals showed that the HBV DNA levels in coinfected hepatocytes were lower than those in cells infected only with HBV. This finding supports the hypothesis of inhibition of HBV replication by HCV. Furthermore, HCV RNA levels were lower in coinfected cells than in cells infected only with HCV, suggesting that HBV may also inhibit HCV replication.

  3. Primary hepatocyte culture in collagen gel mixture and collagen sandwich

    Institute of Scientific and Technical Information of China (English)

    Ying-Jie Wang; Hong-Ling Liu; Hai-Tao Guo; Hong-Wei Wen; Jun Liu

    2004-01-01

    AIM: To explore the methods of hepatocytes culture in a collagen gel mixture or between double layers of collagen sandwich configuration and to examine the functional and cytomorphological characteristics of cultured hepatocytes.METHODS: A two-step collagenase perfusion technique was used to isolate the hepatocytes from Wistar rats or newborn Chinese experimental piglets. The isolated hepatocytes were cultured in a collagen gel mixture or between double layers of collagen sandwich configuration respectively. The former was that rat hepatocytes were mixed with type I rat tail collagen solution till gelled, and the medium was added onto the gel. The latter was that swine hepatocytes were seeded on a plate precoated with collagen gel for 24 h, then another layer of collagen gel was overlaid, resulting in a sandwich configuration. The cytomorphological characteristics, albumin secretion, and LDH-release of the hepatocytes cultured in these two models were examined.RESULTS: Freshly isolated rat hepatocytes were successfully mixed and fixed in collagen gel, and cultured in the gel condition. During the culture period, the urea synthesized and secreted by rat hepatocytes was detected throughout the period. Likewise, newborn experimental piglet hepatocytes were successfully fixed between the double layers of collagen gel, forming a sandwich configuration.Within a week of culture, the albumin secreted by swine hepatocytes was detected by SDS/PAGE analysis. The typical cytomorphological characteristics of the hepatocytes cultured by the above two culture models were found under a phasecontrast microscope. There was little LDH-release during the culture period.CONCLUSION: Both collagen gel mixture and double layers of collagen sandwich configuration can provide cultural conditions much closer to in vivoenvironment, and are helpful for maintaining specific hepatic fiJnctions and cytomorphological characteristics. A collagen gel mixture culture may be more eligible for the

  4. Arsenite alters heme synthesis in long-term cultures of adult rat hepatocytes.

    Science.gov (United States)

    Aguilar-González, M G; Hernández, A; López, M L; Mendoza-Figueroa, T; Albores, A

    1999-06-01

    Arsenite (As[III]) effects on the intermediate steps of heme biosynthesis were studied in adult rat hepatocytes seeded on a feeder layer of 3T3 cells (3T3-hepatocytes) and maintained for 2 weeks with culture medium non-supplemented or supplemented with 150 microM 5-aminolevulinic acid (ALA). The activities of the intracellular enzymes porphobilinogen deaminase (PBG-D), uroporphyrinogen III synthase (UROIII-S), and uroporphyrinogen III decarboxylase (URO-D), and the intermediary uroporphyrins (URO), coproporphyrins (COPRO) and protoporphyrin IX (PROTO) were determined in these cultures. The 3T3-hepatocytes maintained the activities of PBG-D, UROIII-S and URO-D during 2 weeks and ALA addition to the culture medium increased PBG-D (2-3-fold) and UROIII-S (50%) activities and porphyrin production, which accumulated as PROTO. Exposure to 3.9 microM As(III) inhibited UROIII-S activity (down to 34%), and PBG-D and URO-D activities to a lower extent; these effects were magnified by ALA supplementation. As(III) also produced an intracellular accumulation and a decreased excretion of PROTO, and a 31% reduction of the COPRO/URO ratio in the culture medium. Additionally, As(III) caused cytoplasmic vacuolization and lipid accumulation. Our results show that As(III) exposure selectively inhibits several intermediary enzymes of heme metabolism and affects the intra- and extracellular content of porphyrins and their ratio in the culture medium. They also confirm that 3T3-hepatocytes are a suitable in vitro model to study hepatic heme metabolism and its alterations by hepatotoxic chemicals.

  5. The effect of inducing agents on the metabolism of trypanocidal diamidines by isolated rat hepatocytes.

    Science.gov (United States)

    Atsriku, C; Watson, D G; Grant, M H; Skellern, G G

    2003-12-15

    This study has investigated the effect of phenobarbitone (PB), 3-methylcholanthrene (3-MC), and deltamethrin (DM) on the metabolism of two trypanocidal diamidines; pentamidine isethionate and diminazene aceturate in freshly isolated Sprague-Dawley rat hepatocytes. There were significant increases in the total cytochrome p450 content of hepatocytes obtained from rats pre-treated with PB and 3-MC, whereas pre-treatment with DM did not produce any significant induction of cytochrome p450. However, pre-treatment of rats with each of the three agents led to inhibition of pentamidine metabolism following a 3h incubation of pentamidine (100 microM) with freshly isolated rat hepatocytes (5 x 10(6) cells ml(-1)). Pre-treatment with 3-MC caused the highest inhibitory effect on pentamidine metabolism (8-fold inhibition), compared with PB (4.8-fold) and DM (2.2-fold). Six previously reported phase I metabolites of pentamidine were identified in cells from all the pre-treated animals as well as controls. When compared to the control group, there were significant differences between the profiles of the three major metabolites of pentamidine, 1,5-di(4'-amidinophenoxy)-2-pentanol, 1,5-di(4'-amidinophenoxy)-3-pentanol and 5-(4'-amidinophenoxy) pentanoic acid, in hepatocytes from the DM and 3-MC pre-treated rats, whereas no significant differences were observed in the cells from the PB pre-treated group. In contrast, diminazene was not metabolised with the same experimental conditions. Differences in the metabolic profiles of pentamidine and its metabolites as a result of concomitant exposure to environmental xenobiotics could have important toxicological and pharmacological implications for patients that receive the drug.

  6. Stem cell-derived hepatocytes for functional liver replacement

    Directory of Open Access Journals (Sweden)

    Bruno eChrist

    2012-06-01

    Full Text Available Mesenchymal stem cells (MSC represent an alternate cell source to substitute for primary hepatocytes in hepatocyte transplantation because of their multiple differentiation potential and nearly unlimited availability. They may differentiate into hepatocyte-like cells in vitro and maintain specific hepatocyte functions also after transplantation into the regenerating livers of mice or rats both under injury and non-injury conditions. Depending on the underlying liver disease their mode of action is either to replace the diseased liver tissue or to support liver regeneration through their anti-inflammatory and anti-apoptotic as well as their pro-proliferative action.

  7. Deficiency of G1 regulators P53, P21Cip1 and/or pRb decreases hepatocyte sensitivity to TGFβ cell cycle arrest

    Directory of Open Access Journals (Sweden)

    Harrison David J

    2007-11-01

    Full Text Available Abstract Background TGFβ is critical to control hepatocyte proliferation by inducing G1-growth arrest through multiple pathways leading to inhibition of E2F transcription activity. The retinoblastoma protein pRb is a key controller of E2F activity and G1/S transition which can be inhibited in viral hepatitis. It is not known whether the impairment of pRb would alter the growth inhibitory potential of TGFβ in disease. We asked how Rb-deficiency would affect responses to TGFβ-induced cell cycle arrest. Results Primary hepatocytes isolated from Rb-floxed mice were infected with an adenovirus expressing CRE-recombinase to delete the Rb gene. In control cells treatment with TGFβ prevented cells to enter S phase via decreased cMYC activity, activation of P16INK4A and P21Cip and reduction of E2F activity. In Rb-null hepatocytes, cMYC activity decreased slightly but P16INK4A was not activated and the great majority of cells continued cycling. Rb is therefore central to TGFβ-induced cell cycle arrest in hepatocytes. However some Rb-null hepatocytes remained sensitive to TGFβ-induced cell cycle arrest. As these hepatocytes expressed very high levels of P21Cip1 and P53 we investigated whether these proteins regulate pRb-independent signaling to cell cycle arrest by evaluating the consequences of disruption of p53 and p21Cip1. Hepatocytes deficient in p53 or p21Cip1 showed diminished growth inhibition by TGFβ. Double deficiency had a similar impact showing that in cells containing functional pRb; P21Cip and P53 work through the same pathway to regulate G1/S in response to TGFβ. In Rb-deficient cells however, p53 but not p21Cip deficiency had an additive effect highlighting a pRb-independent-P53-dependent effector pathway of inhibition of E2F activity. Conclusion The present results show that otherwise genetically normal hepatocytes with disabled p53, p21Cip1 or Rb genes respond less well to the antiproliferative effects of TGFβ. As the function of

  8. Construction of human naive Fab library, screening and identification of phage antibody against c-Met%人源天然Fab噬菌体抗体库的构建及抗c-Met抗体的筛选、鉴定

    Institute of Scientific and Technical Information of China (English)

    万佳艺; 孙慧; 焦永军; 朱晓娟; 朱进; 刘政; 冯振卿

    2008-01-01

    目的:构建大容量人源天然Fab噬菌体抗体库,筛选抗c-Met特异性抗体并进行初步鉴定.方法:采集20位健康成人的骨髓淋巴细胞.用PCR扩增人Fab片断抗体基因,插入载体pComb3XSS内,构建人源天然Fab抗体库.以固相化的抗原对抗体库进行6轮筛选后,随机挑选60个克隆用Phage ELISA、BstO I酶切片断分析进行检测,阳性克隆作可溶性表达和鉴定.结果:构建的Fab噬菌体抗体库的库容为1.2×109,从中筛选到1株与c-Met特异性结合的人源抗体克隆,命名为AM2-26.DNA序列分析证明为人免疫球蛋白可变区基因,Western blot证实为人源抗c-Met Fab抗体片段,ELISA特异性鉴定阳性.结论:构建了大容量人源天然Fab抗体库,从中获得1株抗c-Met人源Fab抗体片段,有望为抗肿瘤药物的研制提供新的候选分子.

  9. Cryopreservation and gel collagen culture of porcine hepatocytes

    Institute of Scientific and Technical Information of China (English)

    Hong-Ling Liu; Ying-Jie Wang; Hai-Tao Guo; Yu-Ming Wang; Jun Liu; Yue-Cheng Yu

    2004-01-01

    AIM: To study the method of cryopreserving porcine hepatocytes and gel collagen culture measure after its cryopreservation.METHODS: Hepatocytes, isolated from Chinese experimental suckling mini-pigs by two-step perfusion with collagenase using an extra corporeal perfusion apparatus, were cryopreserved with 50 mL/L to 200 mL/L DMSO in liquid nitrogen for 4 mo, then thawed and seeded in 1 or between 2 layers of gel collagen. The expression of porcine albumin message RNA, cellular morphology and content of aspartate aminotransferase (AST) and urea nitrogen (UN) were examined during culture in gel.RESULTS: Viability of 150 mL/L DMSO group thawed hepatocytes was (83±4)%, but after purification, its viability was (90±5)%, attachment efficiency was (86±7)%, the viability of thawed hepatocytes was near to fresh cells. When the thawed hepatocytes were cultivated in gel collagen with culture medium adding epidermal growth factor, the hepatocytes grew in various administrative levels in mixed collagen gel, and bunchy in the sandwich configuration cultures. For up to 10 days' culture, the typical cellular morphological characteristics of cultivated hepatocytes could be observed. The leakage of AST was lower during culture in gel than that in common culture. At the same time, the UN synthesized by cells cultivated in mixed gel collagen was higher than that in other groups.CONCLUSION: Storage in liquid nitrogen can long keep hepatocytes' activities, the concentration of 150 mL/L DMSO is fit for porcine hepatocytes' cryopreservation. Thawed hepatocytes can be cultivated with coliagenous matrix, which provides an environment that more closely resembles that in vivo and maintain the expression of certain liver-specific function of hepatocytes.

  10. Hepatic Stellate Cell-Derived Microvesicles Prevent Hepatocytes from Injury Induced by APAP/H2O2

    Directory of Open Access Journals (Sweden)

    Renwei Huang

    2016-01-01

    Full Text Available Hepatic stellate cells (HSCs, previously described for liver-specific mesenchymal stem cells (MSCs, appear to contribute to liver regeneration. Microvesicles (MVs are nanoscale membrane fragments, which can regulate target cell function by transferring contents from their parent cells. The aim of this study was to investigate the effect of HSC-derived MVs on xenobiotic-induced liver injury. Rat and human hepatocytes, BRL-3A and HL-7702, were used to build hepatocytes injury models by n-acetyl-p-aminophenol n-(APAP or H2O2 treatment. MVs were prepared from human and rat HSCs, LX-2, and HST-T6 and, respectively, added to injured BRL-3A and HL-7702 hepatocytes. MTT assay was utilized to determine cell proliferation. Cell apoptosis was analyzed by flow cytometry and hoechst33258 staining. Western blot was used for analyzing the expression of activated caspase-3. Liver injury indicators, alanine aminotransferase (ALT, aspartate aminotransferase (AST, and lactate dehydrogenase (LDH in culture medium were also assessed. Results showed that (1 HSC-MVs derived from LX-2 and HST-T6 were positive to CD90 and annexin V surface markers; (2 HSC-MVs dose-dependently improved the viability of hepatocytes in both injury models; (3 HSC-MVs dose-dependently inhibited the APAP/H2O2 induced hepatocytes apoptosis and activated caspase-3 expression and leakage of LDH, ALT, and AST. Our results demonstrate that HSC-derived MVs protect hepatocytes from toxicant-induced injury.

  11. Scavenger receptor BI boosts hepatocyte permissiveness to Plasmodium infection.

    NARCIS (Netherlands)

    Yalaoui, S.; Huby, T.; Franetich, J.F.; Gego, A.; Rametti, A.; Moreau, M.; Collet, X.; Siau, A.; Gemert, G.J.A. van; Sauerwein, R.W.; Luty, A.J.F.; Vaillant, J.C.; Hannoun, L.; Chapman, J.; Mazier, D.; Froissard, P.

    2008-01-01

    Infection of hepatocytes by Plasmodium falciparum sporozoites requires the host tetraspanin CD81. CD81 is also predicted to be a coreceptor, along with scavenger receptor BI (SR-BI), for hepatitis C virus. Using SR-BI-knockout, SR-BI-hypomorphic and SR-BI-transgenic primary hepatocytes, as well as s

  12. Serotonin receptor agonist quipazine promotes proliferation and apoptosis of human hepatocyte strain of L-02 strain

    Institute of Scientific and Technical Information of China (English)

    Yang Liu; Zhi-Yong Zhang

    2009-01-01

    BACKGROUND:Liver disease is commonly seen in the clinic and its pathological characteristic is combined hepatocellular death and apoptosis. Promoting hepatocyte regeneration is one of the main methods of treating liver disease. Serotonin (5-HT) is an important compound which participates in various life process, and 95% of it is carried by platelets in the blood. A recent ifnding showed that platelet-derived serotonin is the key factor in liver regeneration, which fails without serotonin. This study aimed to investigate the effects of quipazine, a selective 5-HT receptor agonist, on proliferation and apoptosis in the human hepatocyte strain L-02. METHODS:L-02 cells were cultured in medium with 5-HT and quipazine, and samples were collected at 24, 48, and 72 hours. The methyl thiazolyl tetrazolium (MTT) method was used to test viability, lfow cytometry to assess the cell cycle, the Annexin-V/PI method to evaluate apoptosis, and immunohistochemistry to detect proliferating cell nuclear antigen (PCNA). RESULTS:Compared with the control group, the viability of L-02 cells was improved in the 10, 50, and 250 μg/ml quipazine groups (P0.05); and no difference in the percentage of apoptotic cells was found between the 50μg/ml quipazine and control groups (P>0.05).CONCLUSION:Quipazine improves proliferation of a human hepatocyte strainin vitro, and this is not based on the inhibition of apoptosis.

  13. Mechanism of radiation-induced diacylglycerol production in primary cultured rat hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, Tetsuo; Yukawa, Osami [National Inst. of Radiological Sciences, Chiba (Japan)

    1999-06-01

    Protein kinase C (PKC) is known to be a key enzyme in radiation-induced signal transduction pathways. We have previously demonstrated that {gamma}-irradiation induces PKC activation and translocation from cytosol to membranes as a consequence of membrane lipid peroxidation in cultured rat hepatocytes (Int. J. Radiat. Biol. 70, 473-480, 1996). The present study was undertaken to investigate production of diacylglycerol, an endogenous activator of PKC, following {gamma}-irradiation of hepatocytes. Diacylglycerol content increased 3 min after irradiation, then decreased at 15 min and increased again at 30 min, indicating a biphasic pattern. This result implies participation of diacylglycerol in the radiation-induced activation of PKC in hepatocytes. In order to clarify the mechanism of the initial process of radiation-induced diacylglycerol production, the effects of reactive oxygens were investigated. Treatment of cells with hydroxyl radical, a major oxygen radical produced by radiation, induced diacylglycerol production without any change in the content of phosphatidylcholine, showing a peak at 1 min after treatment. No change in the diacylglycerol content was observed at that time by hydrogen peroxide treatment. Furthermore, the diacylglycerol production by hydroxyl radical was inhibited by pretreatment with neomycin sulfate, a phosphatidylinositol-specific phospholipase C (PI-PLC) inhibitor. These results suggest that radiation exerts PI-PLC activation through hydroxyl radical generation, followed by diacylglycerol production and PKC activation. (author)

  14. Novel regulation of Ski protein stability and endosomal sorting by actin cytoskeleton dynamics in hepatocytes.

    Science.gov (United States)

    Vázquez-Victorio, Genaro; Caligaris, Cassandre; Del Valle-Espinosa, Eugenio; Sosa-Garrocho, Marcela; González-Arenas, Nelly R; Reyes-Cruz, Guadalupe; Briones-Orta, Marco A; Macías-Silva, Marina

    2015-02-13

    TGF-β-induced antimitotic signals are highly regulated during cell proliferation under normal and pathological conditions, such as liver regeneration and cancer. Up-regulation of the transcriptional cofactors Ski and SnoN during liver regeneration may favor hepatocyte proliferation by inhibiting TGF-β signals. In this study, we found a novel mechanism that regulates Ski protein stability through TGF-β and G protein-coupled receptor (GPCR) signaling. Ski protein is distributed between the nucleus and cytoplasm of normal hepatocytes, and the molecular mechanisms controlling Ski protein stability involve the participation of actin cytoskeleton dynamics. Cytoplasmic Ski is partially associated with actin and localized in cholesterol-rich vesicles. Ski protein stability is decreased by TGF-β/Smads, GPCR/Rho signals, and actin polymerization, whereas GPCR/cAMP signals and actin depolymerization promote Ski protein stability. In conclusion, TGF-β and GPCR signals differentially regulate Ski protein stability and sorting in hepatocytes, and this cross-talk may occur during liver regeneration.

  15. Pluripotent stem cell-derived hepatocyte-like cells.

    Science.gov (United States)

    Schwartz, R E; Fleming, H E; Khetani, S R; Bhatia, S N

    2014-01-01

    Liver disease is an important clinical problem, impacting over 30 million Americans and over 600 million people worldwide. It is the 12th leading cause of death in the United States and the 16th worldwide. Due to a paucity of donor organs, several thousand Americans die yearly while waiting for liver transplantation. Unfortunately, alternative tissue sources such as fetal hepatocytes and hepatic cell lines are unreliable, difficult to reproduce, and do not fully recapitulate hepatocyte phenotype and functions. As a consequence, alternative cell sources that do not have these limitations have been sought. Human embryonic stem (hES) cell- and induced pluripotent stem (iPS) cell-derived hepatocyte-like cells may enable cell based therapeutics, the study of the mechanisms of human disease and human development, and provide a platform for screening the efficacy and toxicity of pharmaceuticals. iPS cells can be differentiated in a step-wise fashion with high efficiency and reproducibility into hepatocyte-like cells that exhibit morphologic and phenotypic characteristics of hepatocytes. In addition, iPS-derived hepatocyte-like cells (iHLCs) possess some functional hepatic activity as they secrete urea, alpha-1-antitrypsin, and albumin. However, the combined phenotypic and functional traits exhibited by iHLCs resemble a relatively immature hepatic phenotype that more closely resembles that of fetal hepatocytes rather than adult hepatocytes. Specifically, iHLCs express fetal markers such as alpha-fetoprotein and lack key mature hepatocyte functions, as reflected by drastically reduced activity (~0.1%) of important detoxification enzymes (i.e. CYP2A6, CYP3A4). These key differences between iHLCs and primary adult human hepatocytes have limited the use of stem cells as a renewable source of functional adult hepatocytes for in vitro and in vivo applications. Unfortunately, the developmental pathways that control hepatocyte maturation from a fetal into an adult hepatocyte are

  16. Mechanisms of the statins cytotoxicity in freshly isolated rat hepatocytes.

    Science.gov (United States)

    Abdoli, Narges; Heidari, Reza; Azarmi, Yadollah; Eghbal, Mohammad Ali

    2013-06-01

    Statins are potent drugs, used as lipid-lowering agents in cardiovascular diseases. Hepatotoxicity is one of the serious adverse effects of statins, and the exact mechanism of hepatotoxicity is not yet clear. In this study, the cytotoxic effects of the most commonly used statins, that is, atorvastatin, lovastatin, and simvastatin toward isolated rat hepatocytes, were evaluated. Markers, such as cell death, reactive oxygen species (ROS) formation, lipid peroxidation, mitochondrial membrane potential, and the amount of reduced and oxidized glutathione in the statin-treated hepatocytes, were investigated. It was found that the statins caused cytotoxicity toward rat hepatocytes dose dependently. An elevation in ROS formation, accompanied by a significant amount of lipid peroxidation and mitochondrial depolarization, was observed. Cellular glutathione reservoirs were decreased, and a significant amount of oxidized glutathione was formed. This study suggests that the adverse effect of statins toward hepatocytes is mediated through oxidative stress and the hepatocytes mitochondria play an important role in the statin-induced toxicity.

  17. Dichloroacetate Stimulates Glycogen Accumulation in Primary Hepatocytes through an Insulin-Independent Mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Lingohr, Melissa K.(Washington State University); Bull, Richard J.(SELF-EMPLOYED CONSULTANTS); Kato-Weinstein, Junko (UNIVERSITY PROGRAMS); Thrall, Brian D.(BATTELLE (PACIFIC NW LAB))

    2002-01-01

    Dichloroacetate (DCA), a by-product of water chlorination, causes liver cancer in B6C3F1 mice. A hallmark response observed in mice exposed to carcinogenic doses of DCA is an accumulation of hepatic glycogen content. To distinguish whether the in vivo glycogenic effect of DCA was dependent on insulin and insulin signaling proteins, experiments were conducted in isolated hepatocytes where insulin concentrations could be controlled. In hepatocytes isolated from male B6C3F1 mice, DCA increased glycogen levels in a dose-related manner, independently of insulin. The accumulation of hepatocellular glycogen induced by DCA was not the result of decreased glycogenolysis, since DCA had no effect on the rate of glucagon-stimulated glycogen breakdown. Glycogen accumulation caused by DCA treatment was not hindered by inhibitors of extracellular-regulated protein kinase kinase (Erk1/2 kinase or MEK) or p70 kDa S6 protein kinase (p70(S6K)), but was completely blocked by the phosphatidylinositol 3-kinase (PI3K) inhibitors, LY294002 and wortmannin. Similarly, insulin-stimulated glycogen deposition was not influenced by the Erk1/2 kinase inhibitor, PD098509, or the p70(S6K) inhibitor, rapamycin. Unlike DCA-stimulated glycogen deposition, PI3K-inhibition only partially blocked the glycogenic effect of insulin. DCA did not cause phosphorylation of the downstream PI3K target protein, protein kinase B (PKB/Akt). The phosphorylation of PKB/Akt did not correlate to insulin-stimulated glycogenesis either. Similar to insulin, DCA in the medium decreased IR expression in isolated hepatocytes. The results indicate DCA increases hepatocellular glycogen accumulation through a PI3K-dependent mechanism that does not involve PKB/Akt and is, at least in part, different from the classical insulin-stimulated glycogenesis pathway. Somewhat surprisingly, insulin-stimulated glycogenesis also appears not to involve PKB/Akt in isolated murine hepatocytes.

  18. Reactive nitrogen species in acetaminophen-induced mitochondrial damage and toxicity in mouse hepatocytes.

    Science.gov (United States)

    Burke, Angela S; MacMillan-Crow, Lee Ann; Hinson, Jack A

    2010-07-19

    Acetaminophen (APAP) toxicity in primary mouse hepatocytes occurs in two phases. The initial phase (0-2 h) occurs with metabolism to N-acetyl-p-benzoquinoneimine which depletes glutathione, and covalently binds to proteins, but little toxicity is observed. Subsequent washing of hepatocytes to remove APAP and reincubating in media alone (2-5 h) results in toxicity. We previously reported that the reincubation phase occurs with mitochondrial permeability transition (MPT) and increased oxidative stress (dichlorodihydrofluorescein fluorescence) (DCFH(2)). Since DCFH(2) may be oxidized by multiple oxidative mechanisms, we investigated the role of reactive nitrogen species (RNS) leading to 3-nitrotyrosine in proteins by ELISA and by immunoblots. Incubation of APAP with hepatocytes for 2 h did not result in toxicity or protein nitration; however, washing hepatocytes and reincubating in media alone (2-5 h) resulted in protein nitration which correlated with toxicity. Inclusion of the MPT inhibitor, cyclosporine A, in the reincubation media eliminated toxicity and protein nitration. The general nitric oxide synthase (NOS) inhibitor L-NMMA and the neuronal NOS (NOS1) inhibitor, 7-nitroindazole, added in the reincubation media decreased toxicity and protein nitration; however, neither the inducible NOS (NOS2) inhibitors L-NIL (N6-(1-iminoethyl)-L-lysine) nor SAIT (S-(2-aminoethyl)isothiourea) decreased protein nitration or toxicity. The RNS scavengers, N-acetylcysteine, and high concentrations of APAP, added in the reincubation phase decreased toxicity and protein nitration. 7-Nitroindazole and cyclosporine A inhibited the APAP-induced loss of mitochondrial membrane potential when added in the reincubation phase. The data indicate a role for RNS in APAP induced toxicity.

  19. Role of hepatocyte S6K1 in palmitic acid-induced endoplasmic reticulum stress, lipotoxicity, insulin resistance and in oleic acid-induced protection.

    Science.gov (United States)

    Pardo, Virginia; González-Rodríguez, Águeda; Muntané, Jordi; Kozma, Sara C; Valverde, Ángela M

    2015-06-01

    The excess of saturated free fatty acids, such as palmitic acid, that induces lipotoxicity in hepatocytes, has been implicated in the development of non-alcoholic fatty liver disease also associated with insulin resistance. By contrast, oleic acid, a monounsaturated fatty acid, attenuates the effects of palmitic acid. We evaluated whether palmitic acid is directly associated with both insulin resistance and lipoapoptosis in mouse and human hepatocytes and the impact of oleic acid in the molecular mechanisms that mediate both processes. In human and mouse hepatocytes palmitic acid at a lipotoxic concentration triggered early activation of endoplasmic reticulum (ER) stress-related kinases, induced the apoptotic transcription factor CHOP, activated caspase 3 and increased the percentage of apoptotic cells. These effects concurred with decreased IR/IRS1/Akt insulin pathway. Oleic acid suppressed the toxic effects of palmitic acid on ER stress activation, lipoapoptosis and insulin resistance. Besides, oleic acid suppressed palmitic acid-induced activation of S6K1. This protection was mimicked by pharmacological or genetic inhibition of S6K1 in hepatocytes. In conclusion, this is the first study highlighting the activation of S6K1 by palmitic acid as a common and novel mechanism by which its inhibition by oleic acid prevents ER stress, lipoapoptosis and insulin resistance in hepatocytes.

  20. Concanavalin A/IFN-gamma triggers autophagy-related necrotic hepatocyte death through IRGM1-mediated lysosomal membrane disruption.

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    Chih-Peng Chang

    Full Text Available Interferon-gamma (IFN-γ, a potent Th1 cytokine with multiple biological functions, can induce autophagy to enhance the clearance of the invading microorganism or cause cell death. We have reported that Concanavalin A (Con A can cause autophagic cell death in hepatocytes and induce both T cell-dependent and -independent acute hepatitis in immunocompetent and immunodeficient mice, respectively. Although IFN-γ is known to enhance liver injury in Con A-induced hepatitis, its role in autophagy-related hepatocyte death is not clear. In this study we report that IFN-γ can enhance Con A-induced autophagic flux and cell death in hepatoma cell lines. A necrotic cell death with increased lysosomal membrane permeabilization (LMP is observed in Con A-treated hepatoma cells in the presence of IFN-γ. Cathepsin B and L were released from lysosomes to cause cell death. Furthermore, IFN-γ induces immunity related GTPase family M member 1(IRGM1 translocation to lysosomes and prolongs its activity in Con A-treated hepatoma cells. Knockdown of IRGM1 inhibits the IFN-γ/Con A-induced LMP change and cell death. Furthermore, IFN-γ(-/- mice are resistant to Con A-induced autophagy-associated necrotic hepatocyte death. We conclude that IFN-γ enhances Con A-induced autophagic flux and causes an IRGM1-dependent lysosome-mediated necrotic cell death in hepatocytes.

  1. Isolation and Primary Culture of Rat Hepatocytes Using Kiwifruit Actinidin

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    Z. Shirvani Farsani

    2007-07-01

    Full Text Available Introduction & Objective: Isolation of cells from different tissues rely on proteolytic enzymes mainly collagenases that selectively digest collagen fibers of extra-cellular matrix. It is important to find new and proper collagenases from plant sources. In the present research actinidin, a cysteine protease abundant in Kiwifruit, was used to isolate and culture of rat hepatocytes. Materials & Methods: Different concentrations of actinidin was used to isolate rat hepatocytes by one or two-step perfusion method. The viability of the separated cells was examined by the trypan blue test. The isolated rat hepatocytes were cultured on collagen coated plates in William´s E medium. The morphology of hepatocytes was examined microscopically after staining with the Papanicolaou method.Results: Actinidin in the concentration of 0.4 mg/ml in two-step perfusion method properly isolated hepatocytes from rat liver. The viability of isolated hepatocytes that successfully cultured in collagen coated plates was 90-95 percent.Conclusion: These results showed that actinidin is a proper protease for isolation of hepatocytes. In addition, purification of this enzyme is simpler than the collagenases.

  2. Peroxisome proliferator-activated receptor alpha acts as a mediator of endoplasmic reticulum stress-induced hepatocyte apoptosis in acute liver failure

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    Li Zhang

    2016-07-01

    Full Text Available Peroxisome proliferator-activated receptor α (PPARα is a key regulator to ameliorate liver injury in cases of acute liver failure (ALF. However, its regulatory mechanisms remain largely undetermined. Endoplasmic reticulum stress (ER stress plays an important role in a number of liver diseases. This study aimed to investigate whether PPARα activation inhibits ER stress-induced hepatocyte apoptosis, thereby protecting against ALF. In a murine model of D-galactosamine (D-GalN- and lipopolysaccharide (LPS-induced ALF, Wy-14643 was administered to activate PPARα, and 4-phenylbutyric acid (4-PBA was administered to attenuate ER stress. PPARα activation ameliorated liver injury, because pre-administration of its specific inducer, Wy-14643, reduced the serum aminotransferase levels and preserved liver architecture compared with that of controls. The protective effect of PPARα activation resulted from the suppression of ER stress-induced hepatocyte apoptosis. Indeed, (1 PPARα activation decreased the expression of glucose-regulated protein 78 (Grp78, Grp94 and C/EBP-homologous protein (CHOP in vivo; (2 the liver protection by 4-PBA resulted from the induction of PPARα expression, as 4-PBA pre-treatment promoted upregulation of PPARα, and inhibition of PPARα by small interfering RNA (siRNA treatment reversed liver protection and increased hepatocyte apoptosis; (3 in vitro PPARα activation by Wy-14643 decreased hepatocyte apoptosis induced by severe ER stress, and PPARα inhibition by siRNA treatment decreased the hepatocyte survival induced by mild ER stress. Here, we demonstrate that PPARα activation contributes to liver protection and decreases hepatocyte apoptosis in ALF, particularly through regulating ER stress. Therefore, targeting PPARα could be a potential therapeutic strategy to ameliorate ALF.

  3. Ploidy reductions in murine fusion-derived hepatocytes.

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    Andrew W Duncan

    2009-02-01

    Full Text Available We previously showed that fusion between hepatocytes lacking a crucial liver enzyme, fumarylacetoacetate hydrolase (FAH, and wild-type blood cells resulted in hepatocyte reprogramming. FAH expression was restored in hybrid hepatocytes and, upon in vivo expansion, ameliorated the effects of FAH deficiency. Here, we show that fusion-derived polyploid hepatocytes can undergo ploidy reductions to generate daughter cells with one-half chromosomal content. Fusion hybrids are, by definition, at least tetraploid. We demonstrate reduction to diploid chromosome content by multiple methods. First, cytogenetic analysis of fusion-derived hepatocytes reveals a population of diploid cells. Secondly, we demonstrate marker segregation using ss-galactosidase and the Y-chromosome. Approximately 2-5% of fusion-derived FAH-positive nodules were negative for one or more markers, as expected during ploidy reduction. Next, using a reporter system in which ss-galactosidase is expressed exclusively in fusion-derived hepatocytes, we identify a subpopulation of diploid cells expressing ss-galactosidase and FAH. Finally, we track marker segregation specifically in fusion-derived hepatocytes with diploid DNA content. Hemizygous markers were lost by >or=50% of Fah-positive cells. Since fusion-derived hepatocytes are minimally tetraploid, the existence of diploid hepatocytes demonstrates that fusion-derived cells can undergo ploidy reduction. Moreover, the high degree of marker loss in diploid daughter cells suggests that chromosomes/markers are lost in a non-random fashion. Thus, we propose that ploidy reductions lead to the generation of genetically diverse daughter cells with about 50% reduction in nuclear content. The generation of such daughter cells increases liver diversity, which may increase the likelihood of oncogenesis.

  4. Raman spectroscopic identification of normal and malignant hepatocytes

    Institute of Scientific and Technical Information of China (English)

    Jianyu Guo; Bing Du; Min Qian; Weiying Cai; Zugeng Wang; Zhenrong Sun

    2009-01-01

    Raman spectroscopy has strong potential for providing non-invasion diagnosis of cancers. In this paper, micro-Raman spectroscopy is used to diagnose one most common liver cancer, hepatocellular carcinoma (HCC). The statistical analyzes, including i-test, principal component analysis (PCA), and linear discrim inant analysis (LDA), are performed on the Raman spectra of malignant and normal hepatocytes. The t-test-LDA results show that the 786- and 1004-cm-1 bands of the malignant and normal hepatocytes are significantly different, and PCA-LDA results show an overall accuracy of 100% for the Raman spectro scopic identification of normal and malignant hepatocytes in our experiment.

  5. Stimulatory and inhibitory effects of forskolin on adenylate cyclase in rat normal hepatocytes and hepatoma cells.

    Science.gov (United States)

    Miyamoto, K; Sanae, F; Koshiura, R; Matsunaga, T; Takagi, K; Satake, T; Hasegawa, T

    1989-02-01

    Forskolin synergistically potentiated adenosine 3',5'-cyclic monophosphate formation by prostaglandin E1 (PGE1) in rat normal hepatocytes freshly prepared by collagenase digestion and rat ascites hepatoma AH66 cells, but dose-dependently inhibited the accumulation by PGE1 in AH66F cells. Forskolin activated adenylate cyclase in a dose-dependent manner in homogenates of all cell lines. In normal hepatocytes and AH66 cells, simultaneous addition of forskolin and other adenylate cyclase activators [isoproterenol (IPN), PGE1, guanosine 5'-triphosphate sodium salt (GTP), 5'-guanylylimidodiphosphate sodium salt (Gpp (NH)p), NaF, cholera toxin, islet activating protein and MnCl2] gave greater than additive responses. On the other hand, in AH66F cells, the effect of forskolin on adenylate cyclase was hardly influenced by GTP, but forskolin diminished the activities induced by high concentrations of GTP to that by the diterpene alone. Forskolin also significantly inhibited the PGE1-stimulated and the guanine nucleotide binding regulatory protein-stimulated activities. Because AH66F cells were insensitive to IPN, the combination with forskolin and IPN gave similar activity to that obtained with the diterpene alone. The effect of forskolin on the activation by manganese ion was neither synergistic nor inhibitory but was additive in AH66F cells. These results suggest that forskolin promotes the interaction between the stimulatory guanine nucleotide binding regulatory protein and the catalytic unit in normal hepatocytes and AH66 cells, but in AH66F cells forskolin interferes with the coupling of the two components of adenylate cyclase.

  6. The glucagon-like peptide-1 analogue exendin-4 reverses impaired intracellular Ca(2+) signalling in steatotic hepatocytes.

    Science.gov (United States)

    Ali, Eunüs S; Hua, Jin; Wilson, Claire H; Tallis, George A; Zhou, Fiona H; Rychkov, Grigori Y; Barritt, Greg J

    2016-09-01

    The release of Ca(2+) from the endoplasmic reticulum (ER) and subsequent replenishment of ER Ca(2+) by Ca(2+) entry through store-operated Ca(2+) channels (SOCE) play critical roles in the regulation of liver metabolism by adrenaline, glucagon and other hormones. Both ER Ca(2+) release and Ca(2+) entry are severely inhibited in steatotic hepatocytes. Exendin-4, a slowly-metabolised glucagon-like peptide-1 (GLP-1) analogue, is known to reduce liver glucose output and liver lipid, but the mechanisms involved are not well understood. The aim of this study was to determine whether exendin-4 alters intracellular Ca(2+) homeostasis in steatotic hepatocytes, and to evaluate the mechanisms involved. Exendin-4 completely reversed lipid-induced inhibition of SOCE in steatotic liver cells, but did not reverse lipid-induced inhibition of ER Ca(2+) release. The action of exendin-4 on Ca(2+) entry was rapid in onset and was mimicked by GLP-1 or dibutyryl cyclic AMP. In steatotic liver cells, exendin-4 caused a rapid decrease in lipid (half time 6.5min), inhibited the accumulation of lipid in liver cells incubated in the presence of palmitate plus the SOCE inhibitor BTP-2, and enhanced the formation of cyclic AMP. Hormone-stimulated accumulation of extracellular glucose in glycogen replete steatotic liver cells was inhibited compared to that in non-steatotic cells, and this effect of lipid was reversed by exendin-4. It is concluded that, in steatotic hepatocytes, exendin-4 reverses the lipid-induced inhibition of SOCE leading to restoration of hormone-regulated cytoplasmic Ca(2+) signalling. The mechanism may involve GLP-1 receptors, cyclic AMP, lipolysis, decreased diacylglycerol and decreased activity of protein kinase C.

  7. Cytoprotection by almond skin extracts or catechins of hepatocyte cytotoxicity induced by hydroperoxide (oxidative stress model) versus glyoxal or methylglyoxal (carbonylation model).

    Science.gov (United States)

    Dong, Qiang; Banaich, Monica S; O'Brien, Peter J

    2010-04-29

    Oxidative and carbonyl stress are detrimental in the pathogenesis of diabetic complications, as well as in other chronic diseases. However, this process may be decreased by dietary bioactive compounds. Almond skin is an abundant source of bioactive compounds and antioxidants, including polyphenolic flavonoids, which may contribute to the decrease in oxidative and carbonyl stress. In this study, four Almond Skin Extracts (ASEI, ASEII, ASEIII, and ASEIV) were prepared by different methods and evaluated for their antioxidant activity. The order of the polyphenol content (total muM gallic acid equivalents) of the four extracts was found to be, in decreasing order of effectiveness: ASEI>ASEIII>ASEIV>ASEII. The order of Ferric-reducing antioxidant power (FRAP, microM FeSO(4)/g) value, in decreasing order was ASEI (216)>ASEIII (176)>ASEIV (89)>ASEII (85). The order of ASE effectiveness for decreasing protein carbonyation induced by the copper Fenton reaction was ASEI>ASEIV>ASEII>ASEIII. The order of antioxidant effectiveness for inhibiting tertiary-butyl hydroperoxide (TBH) induced microsomal lipid peroxidation was ASEI>ASEIV>ASEII, ASEIII. Also, the order of ASE effectiveness for inhibiting TBH induced hepatocyte cell death was: ASEIII, ASEIV>ASEI, ASEII. Catechin also protected hepatocytes from TBH induced hepatocyte, lipid peroxidation and cytotoxicity. In a cell free model, equimolar concentrations of catechin or epicatechin rescued serum albumin from protein carbonylation induced by methylglyoxal (MGO). Catechin, epicatechin and ASEI all decreased gloxal induced hepatocyte cell death and reactive oxygen species (ROS) formation in GSH-depleted hepatocytes. Catechin and epicatechin protected against GO or MGO induced hepatocyte cell death, protein carbonylation and ROS formation. Catechin was more effective than epicatechin. Our results suggest that (a) bioactive almond skin constituents in the non-lipophilic polyphenol extract were the most effective at protecting

  8. The effect of 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR on fatty acid oxidation in hepatocytes isolated from neonatal piglets

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    Xi Lin

    2012-10-01

    Full Text Available Abstract In the present study, the effect of 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR on long-chain fatty acid oxidation by hepatocytes isolated from suckled neonatal pig liver (a low ketogenic and lipogenic tissue was tested. Incubation of hepatocytes with AICAR (0.5 mM in the presence of 1 mM of carnitine and 10 mM of glucose for 1 hour at 37°C had no significant effect on total [1-14C]-palmitate (0.5 mM oxidation (14CO2 and 14C-Acid soluble products (ASP. Consistent with the fatty acid oxidation, carnitine palmitoyltransferase I activity and inhibition of its activity by malonyl-CoA (10 μM assayed in cell homogenate also remained constant. However, addition of AICAR to the hepatocytes decreased 14CO2 production by 18% compared to control (p 2 caused a significant difference in distribution of oxidative products between 14CO2 and 14C-ASP (p 14C-ASP. Addition of insulin to hepatocyte incubations with AICAR did not change the oxidative product distribution between CO2 and ASP, but further promoted ACC activity. The increased ACC activity was 70% higher than in the control group when citrate was absent in the reaction medium and was 30% higher when citrate was present in the medium. Our results suggest that AICAR may affect the distribution of metabolic products from fatty acid oxidation by changing ACC activity in hepatocyte isolated from suckled neonatal piglets; however, the basis for the increase in ACC activity elicited by AICAR is not apparent.

  9. Biomechanics and functionality of hepatocytes in liver cirrhosis.

    Science.gov (United States)

    Sun, Shan; Song, Zhenyuan; Cotler, Scott J; Cho, Michael

    2014-06-27

    Cirrhosis is a life-threatening condition that is generally attributed to overproduction of collagen fibers in the extracellular matrix that mechanically stiffens the liver. Chronic liver injury due to causes including viral hepatitis, inherited and metabolic liver diseases and external factors such as alcohol abuse can result in the development of cirrhosis. Progression of cirrhosis leads to hepatocellular dysfunction. While extensive studies to understand the complexity underlying liver fibrosis have led to potential application of anti-fibrotic drugs, no such FDA-approved drugs are currently available. Additional studies of hepatic fibrogenesis and cirrhosis primarily have focused on the extracellular matrix, while hepatocyte biomechanics has received limited attention. The role of hepatocyte biomechanics in liver cirrhosis remains elusive, and how the cell stiffness is correlated with biological functions of hepatocytes is also unknown. In this study, we demonstrate that the biomechanical properties of hepatocytes are correlated with their functions (e.g., glucose metabolism), and that hepatic dysfunction can be restored through modulation of the cellular biomechanics. Furthermore, our results indicate the hepatocyte functionality appears to be regulated through a crosstalk between the Rho and Akt signaling. These novel findings may lead to biomechanical intervention of hepatocytes and the development of innovative tissue engineering for clinical treatment to target liver cells rather than exclusively focusing on the extracellular matrix alone in liver cirrhosis.

  10. alpha-Amanitin induced apoptosis in primary cultured dog hepatocytes.

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    Adam Szelag

    2010-06-01

    Full Text Available Amatoxin poisoning is caused by mushroom species belonging to the genera Amanita, Galerina and Lepiota with the majority of lethal mushroom exposures attributable to Amanita phalloides. High mortality rate in intoxications with these mushrooms is principally a result of the acute liver failure following significant hepatocyte damage due to hepatocellular uptake of amatoxins. A wide variety of amatoxins have been isolated; however, alpha-amanitin (alpha-AMA appears to be the primary toxin. Studies in vitro and in vivo suggest that alpha-AMA does not only cause hepatocyte necrosis, but also may lead to apoptotic cell death. The objective of this study was to evaluate the complex hepatocyte apoptosis in alpha-AMA cytotoxicity. All experiments were performed on primary cultured canine hepatocytes. The cells were incubated for 12 h with alpha-AMA at a final concentration of 1, 5, 10 and 20 microM. Viability test (MTT assay, apoptosis evaluation (TUNEL reaction, detection of DNA laddering and electron microscopy were performed at 6 and 12 h of exposure to alpha-AMA. There was a clear correlation between hepatocyte viability, concentration of alpha-AMA and time of exposure to this toxin. The decline in cultured dog hepatocyte viability during the exposure to alpha-AMA is most likely preceded by enhanced cellular apoptosis. Our results demonstrate that apoptosis might contribute to pathogenesis of the severe liver injury in the course of amanitin intoxication, particularly during the early phase of poisoning.

  11. Effects of betaine on ethanol-stimulated secretion of IGF-Ⅰ and IGFBP-1 in rat primary hepatocytes: involvement of p42/44 MAPK activation

    Institute of Scientific and Technical Information of China (English)

    Myeong Soo Lee; Myung-Sunny Kim; Soo Young Park; Chang-Won Kang

    2006-01-01

    AIM: To evaluate the effects of betaine on the ethanolinduced secretion of IGF-Ⅰ and IGFBP-1 using radioimmunoassay and Western blotting, respectively, in primary cultured rat hepatocytes.METHODS: Hepatocytes isolated from male Sprague-Dawley rats were incubated with various concentrations of ethanol and PD98059 procedures. The hepatocytes were also treated with different doses of betaine (10-5,10-4, and 10-3 mol/L). We measured IGF-Ⅰ and IGFBP-1 using radioimmunoassay and Western blotting, respectively.RESULTS: The ethanol-induced inhibition of IGF-Ⅰ secretion was attenuated by betaine in a concentration-dependent manner in primary cultured rat hepatocytes. At 10-3 mol/L, betaine significantly increased IGF-Ⅰ secretion but decreased IGFBP-1 secretion. In addition, p42/44 mitogen-activated protein kinase (MAPK) activity was accelerated significantly from 10 min to 5 h after treatment with 10-3 mol/L betaine. Furthermore, the changes in IGF-1 and IGFBP-1 secretion resulting from the increased betaine-induced p42/44 MAPK activity in primary cultured rat hepatocytes was blocked by treatment with the MAPK inhibitor PD98059. Betaine treatment blocked the ethanol-induced inhibition of IGF-Ⅰ secretion and p42/44 MAPK activity, and the ethanol-induced increase in IGFBP-1 secretion.CONCLUSION: Betaine modulates the secretion of IGF-Ⅰ and IGFBP-1 via the activation of p42/44 MAPK in primary cultured rat hepatocytes. Betaine also alters the MAPK activations induced by ethanol.

  12. Duck hepatitis B virus covalently closed circular DNA appears to survive hepatocyte mitosis in the growing liver.

    Science.gov (United States)

    Reaiche-Miller, Georget Y; Thorpe, Michael; Low, Huey Chi; Qiao, Qiao; Scougall, Catherine A; Mason, William S; Litwin, Samuel; Jilbert, Allison R

    2013-11-01

    Nucleos(t)ide analogues that inhibit hepatitis B virus (HBV) DNA replication are typically used as monotherapy for chronically infected patients. Treatment with a nucleos(t)ide analogue eliminates most HBV DNA replication intermediates and produces a gradual decline in levels of covalently closed circular DNA (cccDNA), the template for viral RNA synthesis. It remains uncertain if levels of cccDNA decline primarily through hepatocyte death, or if loss also occurs during hepatocyte mitosis. To determine if cccDNA survives mitosis, growing ducklings infected with duck hepatitis B virus (DHBV) were treated with the nucleoside analogue, Entecavir. Viremia was suppressed at least 10(5)-fold, during a period when average liver mass increased 23-fold. Analysis of the data suggested that if cccDNA synthesis was completely inhibited, at least 49% of cccDNA survived hepatocyte mitosis. However, there was a large duck-to-duck variation in cccDNA levels, suggesting that low level cccDNA synthesis may contribute to this apparent survival through mitosis.

  13. The involvement of cytochrome P450 peroxidase in the metabolic bioactivation of cumene hydroperoxide by isolated rat hepatocytes.

    Science.gov (United States)

    Anari, M R; Khan, S; O'Brien, P J

    1996-09-01

    Organic hydroperoxides are believed to be primarily detoxified in cells by the GSH peroxidase/GSSG reductase system and activated to cytotoxic radical species by non-heme iron. However, organic hydroperoxides seem to be bioactivated by cytochrome P450 (P450) in isolated hepatocytes as various P450 (particularly P450 2E1) inhibitors inhibited cumene hydroperoxide (CumOOH) metabolism and attenuated subsequent cytotoxic effects including antimycin A-resistant respiration, lipid peroxidation, iron mobilization, ATP depletion, and cell membrane disruption. CumOOH metabolism was also faster in P450 1A-induced hepatocytes and was inhibited by the P450 1A inhibitor alpha-naphthoflavone. The ferric chelator deferoxamine also prevented cytotoxicity even after CumOOH had been metabolized but had no effect on CumOOH metabolism. This emphasizes the toxicological significance of the iron released following hydroperoxide metabolic activation by cytochrome P450. The radical trap, 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO), had no effect on CumOOH metabolism but prevented CumOOH-induced antimycin A-resistant respiration, lipid peroxidation, iron mobilization, and loss of membrane integrity. These results suggest that CumOOH is metabolically activated by some P450 enzymes (e.g., P450 2E1) in hepatocytes to form reactive radical metabolites or oxidants that cause lipid peroxidation and cytotoxicity.

  14. Force spectroscopy of hepatocytic extracellular matrix components

    Energy Technology Data Exchange (ETDEWEB)

    Yongsunthon, R., E-mail: YongsuntR@Corning.com [Corning Incorporated, SP-FR-01, R1S32D, Corning, NY 14831 (United States); Baker, W.A.; Bryhan, M.D.; Baker, D.E.; Chang, T.; Petzold, O.N.; Walczak, W.J.; Liu, J.; Faris, R.A.; Senaratne, W.; Seeley, L.A.; Youngman, R.E. [Corning Incorporated, SP-FR-01, R1S32D, Corning, NY 14831 (United States)

    2009-07-15

    We present atomic force microscopy and force spectroscopy data of live hepatocytes (HEPG2/C3A liver cell line) grown in Eagle's Minimum Essential Medium, a complex solution of salts and amino acids commonly used for cell culture. Contact-mode imaging and force spectroscopy of this system allowed correlation of cell morphology and extracellular matrix (ECM) properties with substrate properties. Force spectroscopy analysis of cellular 'footprints' indicated that the cells secrete large polymers (e.g., 3.5 {mu}m contour length and estimated MW 1000 kDa) onto their substrate surface. Although definitive identification of the polymers has not yet been achieved, fluorescent-labeled antibody staining has specified the presence of ECM proteins such as collagen and laminin in the cellular footprints. The stretched polymers appear to be much larger than single molecules of known ECM components, such as collagen and heparan sulfate proteoglycan, thus suggesting that the cells create larger entangled, macromolecular structures from smaller components. There is strong evidence which suggests that the composition of the ECM is greatly influenced by the hydrophobicity of the substrate surface, with preferential production and/or adsorption of larger macromolecules on hydrophobic surfaces.

  15. In vitro culture of isolated primary hepatocytes and stem cell-derived hepatocyte-like cells for liver regeneration.

    Science.gov (United States)

    Hu, Chenxia; Li, Lanjuan

    2015-08-01

    Various liver diseases result in terminal hepatic failure, and liver transplantation, cell transplantation and artificial liver support systems are emerging as effective therapies for severe hepatic disease. However, all of these treatments are limited by organ or cell resources, so developing a sufficient number of functional hepatocytes for liver regeneration is a priority. Liver regeneration is a complex process regulated by growth factors (GFs), cytokines, transcription factors (TFs), hormones, oxidative stress products, metabolic networks, and microRNA. It is well-known that the function of isolated primary hepatocytes is hard to maintain; when cultured in vitro, these cells readily undergo dedifferentiation, causing them to lose hepatocyte function. For this reason, most studies focus on inducing stem cells, such as embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs), hepatic progenitor cells (HPCs), and mesenchymal stem cells (MSCs), to differentiate into hepatocyte-like cells (HLCs) in vitro. In this review, we mainly focus on the nature of the liver regeneration process and discuss how to maintain and enhance in vitro hepatic function of isolated primary hepatocytes or stem cell-derived HLCs for liver regeneration. In this way, hepatocytes or HLCs may be applied for clinical use for the treatment of terminal liver diseases and may prolong the survival time of patients in the near future.

  16. Functional hepatocyte heterogeneity. Vascular 2-oxoglutarate is almost exclusively taken up by perivenous, glutamine-synthetase-containing hepatocytes.

    Science.gov (United States)

    Stoll, B; Hüssinger, D

    1989-05-15

    about 100% utilization of the [14C]oxoglutarate taken up by the liver for glutamine synthesis. This was again true for both the antegrade and the retrograde perfusion directions. On the other hand, addition of ammonia did not affect 14CO2 production from labeled oxoglutarate, when glutamine synthetase was inhibited by methionine sulfoximine. 4. The data suggest that vascular oxoglutarate is almost exclusively taken up by the small perivenous hepatocyte population containing glutamine synthetase, i.e. a cell population comprising only 6-7% of all hepatocytes. Thus, the findings demonstrate the existence of a, to date, uniquely zonally distributed oxoglutarate transport system which is probably Na+-dependent in the plasma membrane.(ABSTRACT TRUNCATED AT 400 WORDS)

  17. Epinephrine effects on mitochondrial Krebs cycle are not mediated by typical adrenergic receptors in isolated rat hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Mohan, C.; Memon, R.A.; Bessman, S.P. (Univ. of Southern California, Los Angeles (United States))

    1990-02-26

    Oxidation of 2,3-{sup 14}C succinate (suc) carbons in the intra-mitochondrial Krebs cycle was used as a probe to investigate the effects of epinephrine (epi) on isolated rat hepatocytes. Hepatocytes were incubated at 30{degrees}C in Krebs-Henseleit bicarbonate buffer, pH 7.4, with 0.5 mM concentration of each of the 20 natural amino acids, 0.5 mm concentration of each of the 20 natural amino acids, 2,3-{sup 14}C suc and epi (10 uM), phenylephrine (pheni) (10uM) or isoproterenol (10 uM). Epi and phepi caused a significant increase in {sup 14}CO{sub 2} formation from 2,3-{sup 14}C suc, however, phentolamine, an {infinity}-antagonist, failed to inhibit this increased oxidation of suc carbons. Isoproterenol had no effect on hepatocyte metabolism and propranolol, a {beta}-antagonist, failed to cause any reduction in basal or epi stimulated oxidation of 2,3-{sup 14}C carbons. Unlike insulin, neither epi nor phepi had any significant effect on the anabolic utilization of suc carbons for protein or lipid synthesis. Anabolic channeling of Krebs cycle intermediates into amino acids was reduced by epi treatment of hepatocytes. Although epi treatment can enhance the oxidation of substrate through the Krebs cycle reactions, only insulin is capable of channeling these substrates into anabolic reactions. Data presented also suggest that epi effects on mitochondrial Krebs cycle oxidation are mediated through an atypical {infinity}-adrenergic receptor which is unresponsive to inhibition by non-selective {infinity}-antagonists.

  18. Caffeine induces CYP1A2 expression in rat hepatocytes but not in human hepatocytes.

    Science.gov (United States)

    Vaynshteyn, David; Jeong, Hyunyoung

    2012-06-01

    Caffeine is the active constituent in coffee. Continual consumption of caffeine can lead to an attenuated response also known as tolerance. Results from rat studies have shown that caffeine is an inducer of CYP1A2, the enzyme responsible for caffeine's metabolism. This suggests that CYP1A2 induction by caffeine may be in part responsible for caffeine tolerance. However, whether caffeine induces CYP1A2 expression in humans remains unknown. Our results from luciferase assays performed in HepG2 cells showed that caffeine is not an activator of the aromatic hydrocarbon receptor (AhR), a major transcription factor involved in upregulation of CYP1A2. Furthermore, caffeine did not induce CYP1A2 expression in primary human hepatocytes at a concentration attained by ordinary coffee drinking. On the other hand, caffeine enhanced CYP1A2 expression by 9-fold in rat hepatocytes. Our results suggest that caffeine from ordinary coffee drinking does not induce CYP1A2 expression in humans and that factors other than CYP1A2 induction by caffeine likely contribute to development of caffeine tolerance in humans.

  19. Keratin 8 modulation of desmoplakin deposition at desmosomes in hepatocytes.

    Science.gov (United States)

    Loranger, Anne; Gilbert, Stéphane; Brouard, Jean-Simon; Magin, Thomas M; Marceau, Normand

    2006-12-10

    Keratins, the intermediate filament proteins of epithelial cells, connect to desmosomes, the cell-cell adhesion structures at the surface membrane. The building elements of desmosomes include desmoglein and desmocollin, which provide the actual cell adhesive properties, and desmoplakins, which anchor the keratin intermediate filaments to desmosomes. In the work reported here, we address the role of keratin 8 in modulating desmoplakin deposition at surface membrane in mouse hepatocytes. The experimental approach is based on the use of keratin 8- and keratin 18-null mouse hepatocytes as cell models. In wild-type mouse hepatocytes, desmoplakin is aligned with desmoglein and keratin 8 at the surface membrane. In keratin 8-null hepatocytes, the intermediate filament loss leads to alterations in desmoplakin distribution at the surface membrane, but not of desmoglein. Intriguingly, a significant proportion of keratin 18-null hepatocytes express keratin 8 at the surface membrane, associated with a proper desmoplakin alignment with desmoglein at desmosomes. A Triton treatment of the monolayer reveals that most of the desmoplakin present in either wild-type, keratin 8- or keratin 18-null hepatocytes is insoluble. Deletion analysis of keratin 8 further suggests that the recovery of desmoplakin alignment requires the keratin 8 rod domain. In addition, similarly to other works revealing a key role of desmoplakin phosphorylation on its interaction with intermediate filaments, we find that the phosphorylation status of the keratin 8 head domain affects desmoplakin distribution at desmosomes. Together, the data indicate that a proper alignment/deposition of desmoplakin with keratins and desmoglein in hepatocytes requires keratin 8, through a reciprocal phosphoserine-dependent process.

  20. Suppression of bile acid synthesis by thyroid hormone in primary human hepatocytes

    Institute of Scientific and Technical Information of China (English)

    Ewa Cristine Siljevik Ellis

    2006-01-01

    AIM: It is known that thyroid hormones alter the bile acid metabolism in humans, however the effect on individual enzymes has been difficult to elucidate.This is mainly due to the lack of human liver cell lines producing bile acids. We used cultures of primary human hepatocytes to study the effects of triiodothyronine (T3) on bile acid synthesis.METHODS: Primary hepatocytes were isolated from liver tissue obtained from three different patients undergoing liver resection due to underlying malignancy. The hepatocytes were cultured under serum-free conditions and treated from d 1 to d 5 with culture containing 0.1-1000 nmol/L of T3. Bile acid formation and mRNA levels of key enzymes were analysed.RESULTS: The lowest concentration of T3 decreased cholic acid (CA) formation to 43%-53% of controls and chenodeoxycholic acid (CDCA) to 52%-75% of controls on d 5. The highest dose further decreased CA formation to 16%-48% of controls while CDCA formation remained at 50%-117% of controls. Expression of mRNA levels of cholesterol 7α-hydroxylase (CYP7A1) and sterol 12α-hydroxylase (CYP8B1) dose-dependently decreased.Sterol 27-hydroxylase (CYP27A1) levels also decreased,but not to the same extent.CONCLUSION: T3 dose-dependently decreased total bile acid formation in parallel with decreased expression of CYP7A1 and CYP8B1. CA formation is inhibited to a higher degree than CDCA, resulting in a marked decrease in the CA/CDCA ratio.

  1. The effect of human milk on DNA synthesis of neonatal rat hepatocytes in primary culture.

    Science.gov (United States)

    Kohno, Y; Shiraki, K; Mura, T

    1991-03-01

    We studied the effect of human milk on DNA synthesis of neonatal hepatocytes to elucidate the physiologic role of human milk in growth of the liver. Neonatal hepatocytes were isolated from 5-d-old rats and cultured in serum-free medium. Human milk stimulated DNA synthesis of these hepatocytes in a concentration-dependent manner. The stimulatory activity of 7.5% (vol/vol) human milk plus 0.1 mumol/L insulin was five times that of control and was almost the same as that of 20 micrograms/L human epidermal growth factor (hEGF) plus insulin. The effect of human milk was additive with treatment with hEGF and insulin. The milk associated with prolonged jaundice of infants was significantly more active than the milk that was not associated with jaundice, although the concentration of hEGF was not different between the two types of milk. The mitogenic activity of milk was heat-labile, inactivated by DTT and stable after treatment with trypsin. Three peaks of the activity were detected in milk by gel filtration and the fraction containing proteins of molecular weight between 36,000 and 76,000 showed the highest activity. Anti-hEGF antibody did not inhibit this activity completely. These results suggested the presence of mitogens other than hEGF or a more active form of hEGF in human milk. The milk associated with breast-milk jaundice exerts a different influence on cell growth and may affect maturation of the liver function related to bilirubin metabolism. The mitogenic activity of milk might be important for growth and development of the liver in infants.

  2. Regulation of alpha-1 acid glycoprotein synthesis by porcine hepatocytes in monolayer culture.

    Science.gov (United States)

    Caperna, T J; Shannon, A E; Stoll, M; Blomberg, L A; Ramsay, T G

    2015-07-01

    Alpha-1 acid glycoprotein (AGP, orosomucoid, ORM-1) is a highly glycosylated mammalian acute-phase protein, which is synthesized primarily in the liver and represents the major serum protein in newborn pigs. Recent data have suggested that the pig is unique in that AGP is a negative acute-phase protein in this species, and its circulating concentration appears to be associated with growth rate. The purpose of the present study was to investigate the regulation of AGP synthesis in hepatocytes prepared from suckling piglets and to provide a framework to compare its regulation with that of haptoglobin (HP), a positive acute-phase protein. Hepatocytes were isolated from preweaned piglets and maintained in serum-free monolayer culture for up to 72 h. The influences of hormones, cytokines, and redox modifiers on the expression and secretion of AGP and HP were determined by relative polymerase chain reaction and by measuring the concentration of each protein secreted into culture medium. The messenger RNA abundance and/or secretion of AGP protein was enhanced by interleukin (IL)-17a, IL-1, and resveratrol and inhibited by tumor necrosis factor-α (TNF), oncostatin M, and thyroid hormone (P < 0.05). HP expression and synthesis were upregulated by oncostatin M, IL-6, and dexamethasone and downregulated by TNF (P < 0.01). The overall messenger RNA expression at 24 h was in agreement with the secreted protein patterns confirming that control of these proteins in hepatocytes is largely transcriptional. Moreover, these data support the consideration that AGP is a negative acute-phase reactant and appears to be regulated by cytokines (with the exception of TNF) and hormones primarily in a manner opposite to that of the positive acute-phase protein, HP.

  3. Bone morphogenetic protein-2 is a negative regulator of hepatocyte proliferation downregulated in the regenerating liver

    Institute of Scientific and Technical Information of China (English)

    Cui-Ping Xu; Wen-Min Ji; Gijs R van den Brink; Maikel P Peppelenbosch

    2006-01-01

    AIM: To characterize the expression and dynamic changes of bone morphogenetic protein (BMP)-2 in hepatocytes in the regenerating liver in rats after partial hepatectomy (PH), and examine the effects of BMP-2 on proliferation of human Huh7 hepatoma cells.METHODS: Fifty-four adult male Wistar rats were randomly divided into three groups: A normal control (NC) group, a partial hepatectomized (PH) group and a sham operated (SO) group. To study the effect of liver regeneration on BMP-2 expression, rats were sacrificed before and at different time points after PH or the sham intervention (6, 12, 24 and 48 h). For each time point, six rats were used in parallel. Expression and distribution of BMP-2 protein were determined in regenerating liver tissue by Western blot analysis and immunohistochemistry. Effects of BMP-2 on cell proliferation of human Huh7 hepatoma cell line were assessed using an MTT assay.RESULTS: In the normal liver strong BMP-2 expression was observed around the central and portal veins. The expression of BMP-2 decreased rapidly as measured by both immunohistochemistry and Western blot analysis.This decrease was at a maximum of 3.22 fold after 12 h and returned to normal levels at 48 h after PH. No significant changes in BMP-2 immunoreactivity were observed in the SO group. BMP-2 inhibited serum induced Huh7 cell proliferation.CONCLUSION: BMP-2 is expressed in normal adult rat liver and negatively regulates hepatocyte proliferation.The observed down regulation of BMP-2 following partial hepatectomy suggests that such down regulation may be necessary for hepatocyte proliferation.

  4. Honokiol activates the LKB1–AMPK signaling pathway and attenuates the lipid accumulation in hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Min Suk; Kim, Jung Hwan; Kim, Hye Jung; Chang, Ki Churl; Park, Sang Won, E-mail: parksw@gnu.ac.kr

    2015-04-15

    Honokiol is a bioactive neolignan compound isolated from the species of Magnolia. This study was designed to elucidate the cellular mechanism by which honokiol alleviates the development of non-alcoholic steatosis. HepG2 cells were treated with honokiol for 1 h, and then exposed to 1 mM free fatty acid (FFA) for 24 h to simulate non-alcoholic steatosis in vitro. C57BL/6 mice were fed with a high-fat diet for 28 days, and honokiol (10 mg/kg/day) was daily treated. Honokiol concentration-dependently attenuated intracellular fat overloading and triglyceride (TG) accumulation in FFA-exposed HepG2 cells. These effects were blocked by pretreatment with an AMP-activated protein kinase (AMPK) inhibitor. Honokiol significantly inhibited sterol regulatory element-binding protein-1c (SREBP-1c) maturation and the induction of lipogenic proteins, stearoyl-CoA desaturase-1 (SCD-1) and fatty acid synthase (FAS) in FFA-exposed HepG2 cells, but these effects were blocked by pretreatment of an AMPK inhibitor. Honokiol induced AMPK phosphorylation and subsequent acetyl-CoA carboxylase (ACC) phosphorylation, which were inhibited by genetic deletion of liver kinase B1 (LKB1). Honokiol stimulated LKB1 phosphorylation, and genetic deletion of LKB1 blocked the effect of honokiol on SREBP-1c maturation and the induction of SCD-1 and FAS proteins in FFA-exposed HepG2 cells. Honokiol attenuated the increases in hepatic TG and lipogenic protein levels and fat accumulation in the mice fed with high-fat diet, while significantly induced LKB1 and AMPK phosphorylation. Taken together, our findings suggest that honokiol has an anti-lipogenic effect in hepatocytes, and this effect may be mediated by the LKB1–AMPK signaling pathway, which induces ACC phosphorylation and inhibits SREBP-1c maturation in hepatocytes. - Highlights: • Honokiol attenuates lipid accumulation induced by free fatty acid in hepatocyte. • Honokiol inhibits the increase in lipogenic enzyme levels induced by free fatty

  5. COMMD1-deficient dogs accumulate copper in hepatocytes and provide a good model for chronic hepatitis and fibrosis.

    Directory of Open Access Journals (Sweden)

    Robert P Favier

    Full Text Available New therapeutic concepts developed in rodent models should ideally be evaluated in large animal models prior to human clinical application. COMMD1-deficiency in dogs leads to hepatic copper accumulation and chronic hepatitis representing a Wilson's disease like phenotype. Detailed understanding of the pathogenesis and time course of this animal model is required to test its feasibility as a large animal model for chronic hepatitis. In addition to mouse models, true longitudinal studies are possible due to the size of these dogs permitting detailed analysis of the sequence of events from initial insult to final cirrhosis. Therefore, liver biopsies were taken each half year from five new born COMMD1-deficient dogs over a period of 42 months. Biopsies were used for H&E, reticulin, and rubeanic acid (copper staining. Immunohistochemistry was performed on hepatic stellate cell (HSC activation marker (alpha-smooth muscle actin, α-SMA, proliferation (Ki67, apoptosis (caspase-3, and bile duct and liver progenitor cell (LPC markers keratin (K 19 and 7. Quantitative RT-PCR and Western Blots were performed on gene products involved in the regenerative and fibrotic pathways. Maximum copper accumulation was reached at 12 months of age, which coincided with the first signs of hepatitis. HSCs were activated (α-SMA from 18 months onwards, with increasing reticulin deposition and hepatocytic proliferation in later stages. Hepatitis and caspase-3 activity (first noticed at 18 months increased over time. Both HGF and TGF-β1 gene expression peaked at 24 months, and thereafter decreased gradually. Both STAT3 and c-MET showed an increased time-dependent activation. Smad2/3 phosphorylation, indicative for fibrogenesis, was present at all time-points. COMMD1-deficient dogs develop chronic liver disease and cirrhosis comparable to human chronic hepatitis, although at much higher pace. Therefore they represent a genetically-defined large animal model to test clinical

  6. The endocannabinoid N-arachidonoyl dopamine (NADA) selectively induces oxidative stress-mediated cell death in hepatic stellate cells but not in hepatocytes.

    Science.gov (United States)

    Wojtalla, Alexandra; Herweck, Frank; Granzow, Michaela; Klein, Sabine; Trebicka, Jonel; Huss, Sebastian; Lerner, Raissa; Lutz, Beat; Schildberg, Frank Alexander; Knolle, Percy Alexander; Sauerbruch, Tilman; Singer, Manfred Vincenz; Zimmer, Andreas; Siegmund, Sören Volker

    2012-04-15

    The endocannabinoid system is a crucial regulator of hepatic fibrogenesis. We have previously shown that the endocannabinoid anandamide (AEA) is a lipid mediator that blocks proliferation and induces death in hepatic stellate cells (HSCs), the main fibrogenic cell type in the liver, but not in hepatocytes. However, the effects of other endocannabinoids such as N-arachidonoyl dopamine (NADA) have not yet been investigated. The NADA-synthesizing enzyme tyrosine hydroxylase was mainly expressed in sympathetic neurons in portal tracts. Its expression pattern stayed unchanged in normal or fibrotic liver. NADA dose dependently induced cell death in culture-activated primary murine or human HSCs after 2-4 h, starting from 5 μM. Despite caspase 3 cleavage, NADA-mediated cell death showed typical features of necrosis, including ATP depletion. Although the cannabinoid receptors CB1, CB2, or transient receptor potential cation channel subfamily V, member 1 were expressed in HSCs, their pharmacological or genetic blockade failed to inhibit NADA-mediated death, indicating a cannabinoid-receptor-independent mechanism. Interestingly, membrane cholesterol depletion with methyl-β-cyclodextrin inhibited AEA- but not NADA-induced death. NADA significantly induced reactive oxygen species formation in HSCs. The antioxidant glutathione (GSH) significantly decreased NADA-induced cell death. Similar to AEA, primary hepatocytes were highly resistant against NADA-induced death. Resistance to NADA in hepatocytes was due to high levels of GSH, since GSH depletion significantly increased NADA-induced death. Moreover, high expression of the AEA-degrading enzyme fatty acid amide hydrolase (FAAH) in hepatocytes also conferred resistance towards NADA-induced death, since pharmacological or genetic FAAH inhibition significantly augmented hepatocyte death. Thus the selective induction of cell death in HSCs proposes NADA as a novel antifibrogenic mediator.

  7. Astaxanthin inhibits sodium azide-induced cytotoxicity in hepatocyte L-02 cells probably by H+ transferring function%虾青素可能通过H+传递功能保护NaN3损伤的人胎肝L-02细胞

    Institute of Scientific and Technical Information of China (English)

    马建; 陈海敏; 严小军; 王峰; 徐炜烽

    2011-01-01

    观察虾青素(astaxanthin)对呼吸链复合体Ⅳ抑制剂叠氮钠(NaN)损伤的人胎肝L-02细胞保护作用,并初步探讨其作用机制.100 mmol·L NaN用于构建肝损伤细胞模型,通过测定不同浓度虾青素(0.01、0.10、1.00及10.00 nmol·L)对损伤细胞存活率(MTT检测)、细胞内活性氧(reactive oxygen species,ROS)水平(DCFH-DA检测)、细胞凋亡率(Annexin V-FITC/PI双染法)以及线粒体膜电位(mitochondrial membranepotential,MMP)水平(JC-1法)的影响,发现虾青素能抑制损伤细胞晚期凋亡;对细胞存活率和MMP的保护作用呈现先增加后降低的非剂量依赖性关系,其中0.10 nmol·L虾青素表现为较强的保护作用;实验浓度范围内的虾青素并不能显著降低细胞内ROS水平(P>0.05).为进一步探讨虾青素对损伤细胞的保护作用,人工制备平面双层磷脂膜(planar bilaycr lipid membrane,BLM)模拟线粒体膜,测定不同浓度虾青素(0.1%、2.0%、10.0%)对H的传递能力.结果显示,虾青素对H传递效率无剂量依赖性,中等浓度(2.0%)的虾青素能够较高效率地传递H.结果提示,虾青素对NaN损伤的人胎肝细胞的保护作用与其直接淬灭ROS的抗氧化功能无关,而可能是通过适当浓度下的虾青素对H的高效传递进而维持线粒体膜电位实现的.%This study is to investigate the protective effect of astaxanthin against injured hepatocyte L-02 cells induced by sodium azide (NaN3) and reveal the possible mechanisms. Hepatocyte L-02 cells were exposed to 100 mmol·L-1 NaN3 with various concentrations of astaxanthin pre-incubated, then the cell viability was measured by MTT method; The level of reactive oxygen species (ROS) was determined by DCFH-DA method; The changes of mitochondrial membrane potential (MMP) and apoptosis ratio were detected by JC-1 method and Annexin V-FITC/PI double stain method, respectively. Results showed that after cells were exposed to 100 mmol·L-1 NaN3 for 3 hours, the cell

  8. Morphology and function of isolated hepatocytes transplanted into rat spleen.

    Science.gov (United States)

    Mito, M; Ebata, H; Kusano, M; Onishi, T; Saito, T; Sakamoto, S

    1979-12-01

    Hepatocytes isolated by the collagenase digestive method were transplanted into the spleens of syngeneic rats. Morphology and function of the hepatocytes in the spleen were investigated for 12 to 17 months after transplantation. The transplanted hepatocytes proliferated and reconfigured in the spleen without direct perfusion of portal venous blood and with the presence of an intact host liver. Fourteen to 17 months after transplantation, the hepatocytes which had formed a demarcated nodule occupied approximately 40% of the area of the splenic parenchyma without undifferentiation on microscopic examination. However, the weight of the hepatized spleen did not increase beyond the weight of a normal spleen and the weight of the host liver that had normal morphology also did not differ from a normal liver. Light and electron microscopic studies demonstrated differentiated cord structure and normal architecture for each heptocyte. Furthermore, the hepatized spleen synthesized albumin and glycogen as demonstrated by immunofluorescence and histochemical studies. Ammonia tolerance and indocyanine green clearance tests revealed functioning hepatocytes in the spleen proper. These results indicate that our experimental model lends itself well to investigations in cell growth mechanism and that hepatocellular transplantation has potential clinical application to compensate for impaired hepatic function.

  9. Hepatitis B antigen in hepatocytes of chronic active liver disease.

    Science.gov (United States)

    Kawanishi, H

    1979-04-01

    To study the morphologic interrelation of hepatocytes with the replication of hepatitis B vius (HBV) and immunocompetent cells in chronic active liver disease(CALD), organ cultures were prepared from liver biopsy specimens. Replication of hepatitis B core antigen (HBcAg) appears to occur in the nucleus of the hepatocyte in close association with intranuclear electron-dense strands and sometimes intranucleolar matrixes (likely HBcAg genomes), and cytoplasmic maturation of the HBcAg takes place in the preautolytic condition of host hepatocytes. Immunocompetent cells became progressively autolyzed in the early period of cultures. No difference in progression of hepatocyte injury in tissues from normal subjects and from hepatitis B surface antigen (HBsAg)-positive and HBsAg-negative patients with CALD may suggest that intracellular synthesis of HBV alone is not cytopathic to host hepatocytes. This model is promising for the study of HBV replication and development, and also for testing the efficacy of new antiviral agents against the virus.

  10. In vitro culture of functionally active buffalo hepatocytes isolated by using a simplified manual perfusion method.

    Directory of Open Access Journals (Sweden)

    Santanu Panda

    Full Text Available In farm animals, there is no suitable cell line available to understand liver-specific functions. This has limited our understanding of liver function and metabolism in farm animals. Culturing and maintenance of functionally active hepatocytes is difficult, since they survive no more than few days. Establishing primary culture of hepatocytes can help in studying cellular metabolism, drug toxicity, hepatocyte specific gene function and regulation. Here we provide a simple in vitro method for isolation and short-term culture of functionally active buffalo hepatocytes.Buffalo hepatocytes were isolated from caudate lobes by using manual enzymatic perfusion and mechanical disruption of liver tissue. Hepatocyte yield was (5.3 ± 0.66×107 cells per gram of liver tissue with a viability of 82.3 ± 3.5%. Freshly isolated hepatocytes were spherical with well contrasted border. After 24 hours of seeding onto fibroblast feeder layer and different extracellular matrices like dry collagen, matrigel and sandwich collagen coated plates, hepatocytes formed confluent monolayer with frequent clusters. Cultured hepatocytes exhibited typical cuboidal and polygonal shape with restored cellular polarity. Cells expressed hepatocyte-specific marker genes or proteins like albumin, hepatocyte nuclear factor 4α, glucose-6-phosphatase, tyrosine aminotransferase, cytochromes, cytokeratin and α1-antitrypsin. Hepatocytes could be immunostained with anti-cytokeratins, anti-albumin and anti α1-antitrypsin antibodies. Abundant lipid droplets were detected in the cytosol of hepatocytes using oil red stain. In vitro cultured hepatocytes could be grown for five days and maintained for up to nine days on buffalo skin fibroblast feeder layer. Cultured hepatocytes were viable for functional studies.We developed a convenient and cost effective technique for hepatocytes isolation for short-term culture that exhibited morphological and functional characteristics of active hepatocytes

  11. The effects of human umbilical cord perivascular cells on rat hepatocyte structure and functional polarity.

    Science.gov (United States)

    Gómez-Aristizábal, Alejandro; Davies, John Edward

    2013-06-01

    Hepatocyte culture is a useful tool for the study of their biology and the development of bioartificial livers. However, many challenges have to be overcome since hepatocytes rapidly lose their normal phenotype in vitro. We have recently demonstrated that human umbilical cord perivascular cells (HUCPVCs) are able to provide support to hepatocytes. In the present study we go further into exploring the effects that HUCPVCs have in the functional polarization, and both the internal and external organization, of hepatocytes. Also, we investigate HUCPVC-hepatocyte crosstalk by tracking both the effects of HUCPVCs on hepatocyte transcription factors and those of hepatocytes on the expression of hepatotrophic factors in HUCPVCs. Our results show that HUCPVCs maintain the functional polarity of hepatocytes ex vivo, as judged by the secretion of fluorescein into bile canaliculi, for at least 40 days. Transmission electron microscopy revealed that hepatocytes in coculture organize in an organoid-like structure embedded in extracellular matrix surrounded by HUCPVCs. In coculture, hepatocytes displayed a higher expression of C/EBPα, implicated in maintenance of the mature hepatocyte phenotype, and HUCPVCs upregulated hepatocyte growth factor and Jagged1 indicating that these genes may play important roles in HUCPVC-hepatocyte interactions.

  12. THE PROGNOSTIC RESEARCH AND RELATIONSHIP BETWEEN HELICOBACTER PYLORI AND EXPRESSION OF C-MET ONCOGENE IN GASTRIC CARCINOMAS%胃癌中幽门螺杆菌感染与原癌基因c-met表达及预后研究

    Institute of Scientific and Technical Information of China (English)

    庄小强; 孙桂华; 林三仁; 郑杰; 李燕; 王立新

    2001-01-01

    Aim To determine whether there is a relationship betweenHelicobacter pylori(Hp) and expression of c-met oncogene in gastric mucosal lesions,and prognostic significance of gastric carcinomas(GC).Methods Hp and expression of c-met were investigated in 145 gastric mucosal lesions by using immunohistochemistry,and Hp was examined by Warthin-starry method.Results For chronic superficial gastritis (CSG),chronic atrophic gastritis and intestinal mataplasia (CAG+IM),dysplasia(DYS),early GC and advanced GC,the expression rates of c-met were 25.53%,51.28%,61.54%,66.67% and 68.42%.The positive rates were higher in CAG+IM,DYS and GC than in CSG(P<0.05).Expressions of c-met of Hp positive were higher than Hp negative in intestinal GC(P<0.05).Expressions of c-met were correlated significantly with Hp positive in CAG+IM,DYS and GC.The survival rate of patients with Hp non-infection.Conclusions Hp infection and expression of c-met may be associated with in proliferation and malignant transformation of gastric mucosa.Hp infection is associated with prognosis of gastric carcinoma.%目的 研究幽门螺杆菌(Hp)感染的胃癌(GC)组织中c-met表达及(Hp)感染对胃癌预后的影响。方法 经病理证实,不同病变胃粘膜145例以免疫组化检测c-met基因表达,以W-S法及快速尿素酶试验检测(Hp)感染。结果 在浅表性胃炎(CSG)、萎缩肠化生胃炎(CAG+IM)、异型增生(DYS)、早期GC和进展期GC中,c-met基因表达率分别为25.53%,51.28%,61.54%,66.67%和68.42%,CAG+IM、DYS、GC均显著高于CSG(P<0.05)。肠型胃癌c-met阳性表达与(Hp)感染密切相关。CAG+IM,DYS和GC组c-met阳性表达(Hp)感染者明显高于阴性组。(Hp)阳性者5年生存期显著短于(Hp)阴性者。结论 (Hp)感染和c-met表达与胃粘膜增殖和恶化有关,前者也与胃癌预后有关。

  13. Potential hepatoprotective effects of new Cuban natural products in rat hepatocytes culture.

    Science.gov (United States)

    Rodeiro, I; Donato, M T; Martínez, I; Hernández, I; Garrido, G; González-Lavaut, J A; Menéndez, R; Laguna, A; Castell, J V; Gómez-Lechón, M J

    2008-08-01

    The protective effects of five Cuban natural products (Mangifera indica L. (MSBE), Erythroxylum minutifolium, Erythroxylum confusum, Thalassia testudinum and Dictyota pinnatifida extracts and mangiferin) on the oxidative damage induced by model toxicants in rat hepatocyte cultures were studied. Cells were pre-incubated with the natural products (5-200 microg/mL) for 24 h. Then hepatotoxins (tert-butyl hydroperoxide, ethanol, carbon tetrachloride and lipopolysaccharide) were individually added and post-incubated for another 24 h. After treatments, cell viability was determined using the MTT assay. Mangiferin and MSBE exhibited the highest cytoprotective potential (EC50 between 50 and 125 microg/mL), followed by T. testudinum and Erythroxylum extracts, whereas no significant protective effects was produced by Dictyota extract treatment. Antioxidant properties of the natural products against lipid peroxidation and GSH depletion induced by tert-butyl hydroperoxide were then investigated. The results show that at 36 h pre-treatment of cells with mangiferin or MSBE, concentrations of T. testudinum and Erythroxylum extracts ranging from 25 to 100 microg/mL significantly inhibited lipid peroxidation induced by tert-butyl hydroperoxide (100 and 250 microM) and increased the GSH levels reduced by the toxicant. D. pinnatifida inhibited lipid peroxidation, but did not preserve GSH levels. In conclusion, MSBE, E. minutifolium, E. confusum and T. testudinum extracts and mangiferin showed hepatoprotective activity against induced damage in all the experimental series, where mangiferin and the extracts of MSBE and T. testudinum were the best candidates to inhibit "in vitro" damage to rat hepatocytes. This hepatoprotective effect found could be associated with the antioxidant properties observed for the products.

  14. Fatty acids-stress attenuates gluconeogenesis induction and glucose production in primary hepatocytes

    Directory of Open Access Journals (Sweden)

    Budick-Harmelin Noga

    2012-07-01

    Full Text Available Abstract Background Hepatic gluconeogenesis tightly controls blood glucose levels in healthy individuals, yet disorders of fatty acids (FAs oxidation are characterized by hypoglycemia. We studied the ability of free-FAs to directly inhibit gluconeogenesis, as a novel mechanism that elucidates the hypoglycemic effect of FAs oxidation defects. Methods Primary rat hepatocytes were pre-treated with FAs prior to gluconeogenic stimuli with glucagon or dexamethasone and cAMP. Results Pre-treatment with 1 mM FAs (mixture of 2:1 oleate:palmitate for 1 hour prior to gluconeogenic induction, significantly decreases the induced expression of the gluconeogenic genes phosphoenolpyruvate carboxykinase (PEPCK and glucose-6-phosphatase (G6pase as well as the induced glucose production by the cells. The inhibitory effect of FAs upon gluconeogenesis is abolished when pre-treatment is elongated to 18 hours, allowing clearance of FAs into triglycerides by the cells. Replacement of palmitate with the non-metabolic fatty acid 2-bromopalmitate inhibits esterification of FAs into triglycerides. Accordingly, the increased exposure to unesterified-FAs allows their inhibitory effect to be extended even when pre-treatment is elongated to 18 hours. Similar changes were caused by FAs to the induction of peroxisome-proliferator-activated receptor-γ coactivator 1α (PGC1α expression, indicating this transcriptional coactivator as the mediating link of the effect. This inhibitory effect of FAs upon gluconeogenic induction is shown to involve reduced activation of cAMP response element-binding (CREB transcription factor. Conclusions The present results demonstrate that free-FAs directly inhibit the induced gluconeogenic response in hepatocytes. Hence, high levels of free-FAs may attenuate hepatic gluconeogenesis, and liver glucose output.

  15. Gelsolin-mediated activation of PI3K/Akt pathway is crucial for hepatocyte growth factor-induced cell scattering in gastric carcinoma.

    Science.gov (United States)

    Huang, Baohua; Deng, Shuo; Loo, Ser Yue; Datta, Arpita; Yap, Yan Lin; Yan, Benedict; Ooi, Chia Huey; Dinh, Thuy Duong; Zhuo, Jingli; Tochhawng, Lalchhandami; Gopinadhan, Suma; Jegadeesan, Tamilarasi; Tan, Patrick; Salto-Tellez, Manuel; Yong, Wei Peng; Soong, Richie; Yeoh, Khay Guan; Goh, Yaw Chong; Lobie, Peter E; Yang, Henry; Kumar, Alan Prem; Maciver, Sutherland K; So, Jimmy B Y; Yap, Celestial T

    2016-05-01

    In gastric cancer (GC), the main subtypes (diffuse and intestinal types) differ in pathological characteristics, with diffuse GC exhibiting early disseminative and invasive behaviour. A distinctive feature of diffuse GC is loss of intercellular adhesion. Although widely attributed to mutations in the CDH1 gene encoding E-cadherin, a significant percentage of diffuse GC do not harbor CDH1 mutations. We found that the expression of the actin-modulating cytoskeletal protein, gelsolin, is significantly higher in diffuse-type compared to intestinal-type GCs, using immunohistochemical and microarray analysis. Furthermore, in GCs with wild-type CDH1, gelsolin expression correlated inversely with CDH1 gene expression. Downregulating gelsolin using siRNA in GC cells enhanced intercellular adhesion and E-cadherin expression, and reduced invasive capacity. Interestingly, hepatocyte growth factor (HGF) induced increased gelsolin expression, and gelsolin was essential for HGF-medicated cell scattering and E-cadherin transcriptional repression through Snail, Twist and Zeb2. The HGF-dependent effect on E-cadherin was found to be mediated by interactions between gelsolin and PI3K-Akt signaling. This study reveals for the first time a function of gelsolin in the HGF/cMet oncogenic pathway, which leads to E-cadherin repression and cell scattering in gastric cancer. Our study highlights gelsolin as an important pro-disseminative factor contributing to the aggressive phenotype of diffuse GC.

  16. Gelsolin-mediated activation of PI3K/Akt pathway is crucial for hepatocyte growth factor-induced cell scattering in gastric carcinoma

    Science.gov (United States)

    Huang, Baohua; Deng, Shuo; Loo, Ser Yue; Datta, Arpita; Yap, Yan Lin; Yan, Benedict; Ooi, Chia Huey; Dinh, Thuy Duong; Zhuo, Jingli; Tochhawng, Lalchhandami; Gopinadhan, Suma; Jegadeesan, Tamilarasi; Tan, Patrick; Salto-Tellez, Manuel; Yong, Wei Peng; Soong, Richie; Yeoh, Khay Guan; Goh, Yaw Chong; Lobie, Peter E.; Yang, Henry; Kumar, Alan Prem; Maciver, Sutherland K.; So, Jimmy B.Y.; Yap, Celestial T.

    2016-01-01

    In gastric cancer (GC), the main subtypes (diffuse and intestinal types) differ in pathological characteristics, with diffuse GC exhibiting early disseminative and invasive behaviour. A distinctive feature of diffuse GC is loss of intercellular adhesion. Although widely attributed to mutations in the CDH1 gene encoding E-cadherin, a significant percentage of diffuse GC do not harbor CDH1 mutations. We found that the expression of the actin-modulating cytoskeletal protein, gelsolin, is significantly higher in diffuse-type compared to intestinal-type GCs, using immunohistochemical and microarray analysis. Furthermore, in GCs with wild-type CDH1, gelsolin expression correlated inversely with CDH1 gene expression. Downregulating gelsolin using siRNA in GC cells enhanced intercellular adhesion and E-cadherin expression, and reduced invasive capacity. Interestingly, hepatocyte growth factor (HGF) induced increased gelsolin expression, and gelsolin was essential for HGF-medicated cell scattering and E-cadherin transcriptional repression through Snail, Twist and Zeb2. The HGF-dependent effect on E-cadherin was found to be mediated by interactions between gelsolin and PI3K-Akt signaling. This study reveals for the first time a function of gelsolin in the HGF/cMet oncogenic pathway, which leads to E-cadherin repression and cell scattering in gastric cancer. Our study highlights gelsolin as an important pro-disseminative factor contributing to the aggressive phenotype of diffuse GC. PMID:27058427

  17. Effect of Liver Damage and Hyperbaric Oxygenation on Glutamine Synthetase of Hepatocytes.

    Science.gov (United States)

    Savilov, P N; Yakovlev, V N

    2016-01-01

    Activity of glutamine synthetase in the hepatocytes of healthy animals and animals with chronic CCl4-induced hepatitis was studied on white mature female rats after liver resection (15-20% of organ weight) and hyperbaric oxygenation (3 atm, 50 min, 3 times). Surgically operated left and non-operated middle lobes of the liver were analyzed on day 3 after liver resection and exposure to hyperbaric oxygenation. On day 65 of CCl4 poisoning, activity of glutamine synthetase decreased in both lobes and did not recover on day 3 after toxin cessation. Liver resection under conditions of CCl4-induced hepatitis restored reduced activity of glutamine synthetase in both liver lobes to the normal level. In healthy rats, the increase in glutamine synthetase activity after liver resection was found only in the middle lobe of the liver. Hyperbaric oxygenation enhanced the stimulatory effect of liver resection on glutamine synthetase activity in hepatocytes during chronic CCl4-induced hepatitis. In healthy animals with liver resection, activity of glutamine synthetase did not change after hyperbaric oxygenation, while normally oxygenation inhibited glutamine synthetase activity.

  18. Selective protection of normal hepatocytes by indocyanine green in photodynamic therapy for the hepatoma of rat

    Science.gov (United States)

    Gu, Ying; Li, Junheng; Guo, Zhong-He

    1993-03-01

    Using hepatocarcinoma transplanted rats, the present study made consecutive observation for the color change and indocyanine green (ICG) absorption peak of the normal liver and tumor tissues after intravenous injection of ICG. The normal liver tissue of the rat was found to turn violet-green soon after ICG injection and the optic density (OD) of ICG-characteristic spectral peak of the tissue homogenate reached its maximum value at 35 minutes post-injection, while neither color change nor OD value increase was noticed in the tissue of transplanted hepatocarcinoma, suggesting that there is a specific absorption of ICG by the normal liver tissue. Chemiluminescentoassay revealed inhibited luminal chemiluminescence by ICG, indicating the depression of singlet oxygen and reactive oxygen species (ROS) oxidation during HPD photosensitization by ICG. In PDT of the hepatocarcinoma, the irradiated area was examined under microscope and auto-microimage analysis system after ICG administration. For tumor-free tissue, the photosensitization induced necrotic area was found smaller in those with than those without ICG administration, whereas the tumor killing effect was almost the same of the two. It is suggested that ICG may offer selective protection for healthy hepatocytes without diminishing the destruction of tumor cells. The protection of healthy hepatocytes by ICG is thought to be in accordance with the amount of ICG in the cell and the distribution of light energy.

  19. Resistin induces insulin resistance, but does not affect glucose output in rat-derived hepatocytes

    Institute of Scientific and Technical Information of China (English)

    Feng LIU; Xiao-qing PAN; Mei GUO; Rong-hua CHEN; Xi-rong GUO; Tao YANG; Bin WANG; Min ZHANG; Nan GU; Jie QIU; Hong-qi FAN; Chun-mei ZHANG; Li FEI

    2008-01-01

    Aim: The aim of the present study was to observe the effects of resistin on insulin sensitivity and glucose output in rat-derived hepatocytes. Methods: The rat hepatoma cell line H4IIE was cultured and stimulated with resistin; supernant glucose and glycogen content were detected. The insulin receptor substrate (IRS)-1 and IRS-2, protein kinase B/Akt, glycogen synthase kinase-3β (GSK-3β), the suppressor of cytokine signaling 3 (SOCS-3) protein content, as well as the phosphorylation status were assessed by Western blotting. Specific antisense oligodeoxynucleotides directed against SOCS-3 were used to knockdown SOCS-3. Results: Resistin induced insulin resistance, but did not affect glucose output in rat hepatoma cell line H4IIE. Resistin attenuated multiple effects of insulin, including insulin-stimulated glycogen synthesis and phosphorylation of IRS, pro-tein kinase B/Akt, as well as GSK-3β. Resistin treatment markedly induced the gene and protein expression of SOCS-3, a known inhibitor of insulin signaling. Furthermore, a specific antisense oligodeoxynucleotide directed against SOCS-3 treatment prevented resistin from antagonizing insulin action. Conclusion: The major function of resistin on liver is to induce insulin resistance. SOCS-3 induc-tion may contribute to the resistin-mediated inhibition of insulin signaling in H4IIE hepatocytes.

  20. Down-regulation of MiR-127 facilitates hepatocyte proliferation during rat liver regeneration.

    Directory of Open Access Journals (Sweden)

    Chuanyong Pan

    Full Text Available Liver regeneration (LR after partial hepatectomy (PH involves the proliferation and apoptosis of hepatocytes, and microRNAs have been shown to post-transcriptionally regulate genes involved in the regulation of these processes. To explore the role of miR-127 during LR, the expression patterns of miR-127 and its related proteins were investigated. MiR-127 was introduced into a rat liver cell line to examine its effects on the potential target genes Bcl6 and Setd8, and functional studies were undertaken. We discovered that miR-127 was down-regulated and inversely correlated with the expression of Bcl6 and Setd8 at 24 hours after PH, a time at which hypermethylation of the promoter region of the miR-127 gene was detected. Furthermore, in BRL-3A rat liver cells, we observed that overexpression of miR-127 significantly suppressed cell growth and directly inhibited the expression of Bcl6 and Setd8. The results suggest that down-regulation of miR-127 may be due to the rapid methylation of its promoter during the first 24 h after PH, and this event facilitates hepatocyte proliferation by releasing Bcl6 and Setd8. These findings support a miRNA-mediated negative regulation pattern in LR and implicate an anti-proliferative role for miR-127 in liver cells.

  1. Alternative Cell Sources to Adult Hepatocytes for Hepatic Cell Therapy.

    Science.gov (United States)

    Pareja, Eugenia; Gómez-Lechón, María José; Tolosa, Laia

    2017-01-01

    Adult hepatocyte transplantation is limited by scarce availability of suitable donor liver tissue for hepatocyte isolation. New cell-based therapies are being developed to supplement whole-organ liver transplantation, to reduce the waiting-list mortality rate, and to obtain more sustained and significant metabolic correction. Fetal livers and unsuitable neonatal livers for organ transplantation have been proposed as potential useful sources of hepatic cells for cell therapy. However, the major challenge is to use alternative cell sources for transplantation that can be derived from reproducible methods. Different types of stem cells with hepatic differentiation potential are eligible for generating large numbers of functional hepatocytes for liver cell therapy to treat degenerative disorders, inborn hepatic metabolic diseases, and organ failure. Clinical trials are designed to fully establish the safety profile of such therapies and to define target patient groups and standardized protocols.

  2. Protective effect of liver ischemic preconditioning on rat hepatocytes

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Ischemic preconditioning (IPC) protects liver graft function following ischemia in liver transplantation and liver resection. The aim of this study was to assess the advantages and any potential disadvantages of liver IPC prior to isolation for rat hepatocytes during isolation and cryopreservation. After isolating and thawing the cryopreserved hepatocytes after 14 and 28 d,cell viability,efficiency,and lactate dehydrogenase (LDH) levels in preserve solution were examined for every group. Groups treated with IPC had better cell viability determination,assessment of plating efficiency and lactate dehydrogenase (LDH) assay than Group without IPC,suggesting that IPC prior to isolation may have a significant protective effect on hepatocytes subjected to isolation and short period cryopreservation.

  3. Acetaminophen metabolism, cytotoxicity, and genotoxicity in rat primary hepatocyte cultures

    Energy Technology Data Exchange (ETDEWEB)

    Milam, K.M.; Byard, J.L.

    1985-06-30

    Acetaminophen (APAP) metabolism, cytotoxicity, and genotoxicity were measured in primary cultures of rat hepatocytes. Although 3 mM APAP caused a slight increase in cellular release of lactate dehydrogenase into the culture medium, cellular glutathione concentration (an index of APAP metabolism) was reduced by 50%. APAP at 7 mM was significantly more toxic to these hepatocytes and had a similar but more marked effect on glutathione concentrations. In spite of its cytotoxicity, neither dose of APAP stimulated DNA repair synthesis when monitored by the rate of incorporation of (/sup 3/H)thymidine into DNA following exposure to APAP. Thus, although APAP has been shown to be both hepato- and nephrotoxic in several in vivo and in vitro systems, the reactive toxic metabolite of APAP is not genotoxic in rat primary hepatocyte cultures.

  4. Morphological and functional behaviors of rat hepatocytes cultured on single-walled carbon nanotubes.

    Science.gov (United States)

    Koga, Haruka; Fujigaya, Tsuyohiko; Nakashima, Naotoshi; Nakazawa, Kohji

    2011-09-01

    This study describes the morphological and functional behaviors of rat hepatocytes on single-walled carbon nanotube (CNT)-coated surfaces. Although the hydrophobic characteristics of CNT-coated surfaces increased with increasing CNT density, hepatocyte adhesion decreased, indicating that the interaction between hepatocytes and CNTs is weak. We found that hepatocytes on a CNT-coated surface gradually gather together and form spheroids (spherical multicellular aggregates). These spheroids exhibit compact spherical morphology with a smooth surface and express connexin-32, an intracellular communication molecule. In contrast, collagen treatment in conjunction with the CNT-coated surface improved hepatocyte adhesion, and the cells maintained a monolayer configuration throughout the culture period. The albumin secretion and ammonia removal activities of hepatocyte spheroids were maintained at elevated levels for at least 15 days of culturing as compared with hepatocyte monolayers. These results indicate that CNTs can be used for the formation and long-term culture of hepatocyte spheroids.

  5. In vivo hepatocyte MR imaging using lactose functionalized magnetoliposomes.

    Science.gov (United States)

    Ketkar-Atre, Ashwini; Struys, Tom; Dresselaers, Tom; Hodenius, Michael; Mannaerts, Inge; Ni, Yicheng; Lambrichts, Ivo; Van Grunsven, Leo A; De Cuyper, Marcel; Himmelreich, Uwe

    2014-01-01

    The aim of this study was to assess a novel lactose functionalized magnetoliposomes (MLs) as an MR contrast agent to target hepatocytes as well as to evaluate the targeting ability of MLs for in vivo applications. In the present work, 17 nm sized iron oxide cores functionalized with anionic MLs bearing lactose moieties were used for targeting the asialoglycoprotein receptor (ASGP-r), which is highly expressed in hepatocytes. Non-functionalized anionic MLs were tested as negative controls. The size distribution of lactose and anionic MLs was determined by transmission electron microscopy (TEM) and dynamic light scattering (DLS). After intravenous administration of both MLs, contrast enhancement in the liver was observed by magnetic resonance imaging (MRI). Label retention was monitored non-invasively by MRI and validated with Prussian blue staining and TEM for up to eight days post MLs administration. Although the MRI signal intensity did not show significant differences between functionalized and non-functionalized particles, iron-specific Prussian blue staining and TEM analysis confirmed the uptake of lactose MLs mainly in hepatocytes. In contrast, non-functionalized anionic MLs were mainly taken up by Kupffer and sinusoidal cells. Target specificity was further confirmed by high-resolution MR imaging of phantoms containing isolated hepatocytes, Kupffer cell (KCs) and hepatic stellate cells (HSCs) fractions. Hypointense signal was observed for hepatocytes isolated from animals which received lactose MLs but not from animals which received anionic MLs. These data demonstrate that galactose-functionalized MLs can be used as a hepatocyte targeting MR contrast agent to potentially aid in the diagnosis of hepatic diseases if the non-specific uptake by KCs is taken into account.

  6. Intrasplenic transplantation of allogeneic hepatocytes prolongs survival in anhepatic rats.

    Science.gov (United States)

    Arkadopoulos, N; Lilja, H; Suh, K S; Demetriou, A A; Rozga, J

    1998-11-01

    To examine whether hepatocytes transplanted in the spleen can function as an ectopic liver, we performed hepatocyte transplantation in rats that were rendered anhepatic. Total hepatectomy was performed by using a novel single-stage technique. Following hepatectomy, Group 1 rats (n = 16) were monitored until death to determine survival time without prior intervention. Group 2 anhepatic rats (n = 20) were sacrificed at various times to measure blood hepatocyte growth factor (HGF) and transforming growth factor beta1 (TGF-beta1) levels. Group 3 (n = 16) rats received intrasplenic injection of isolated hepatocytes (2.5 x 10(7) cells/rat) followed by total hepatectomy after 3 days. Group 4 (n = 12) sham-transplanted rats received intrasplenic saline infusion, and after 3 days they were rendered anhepatic. Group 2, 3, and 4 rats were maintained on daily Cyclosporine A (10 mg/kg; intramuscularly). Group 1 anhepatic rats survived for 22.4 +/- 5.2 hours (standard deviation). The anhepatic state was associated with a progressive and statistically significant rise in blood HGF and TGF-beta1 levels. Rats that received hepatocyte transplantation before total hepatectomy had a significantly longer survival time than sham-transplanted anhepatic controls (34.1 +/- 8.5 vs. 15.5 +/- 4.8 hrs, P ammonia, prothrombin time, international normalized ratio, and TGF-beta1 levels when compared with sham-transplanted controls. In conclusion, intrasplenic transplantation of allogeneic hepatocytes prolonged survival, improved blood chemistry, and lowered blood TGF-beta1 levels in rats rendered anhepatic.

  7. Biological effects of extract from newborn porcine liver on hepatocytes, hepatic stellate cells, and hepatoma cell line

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Objective: Porcine liver extract has been shown to be effective in the clinical treatment of severe hepatitis. The aim of the present study was to study its antifibrotic as well as immune regulatory effect in vitro. Methods: Hepatocytes, hepatic stellate cells (HSCs), hepatoma cell line (HepG2) and human peripheral blood mononuclear cells (PMNCs) were studied with respect to proliferation, extracellular matrix production and apoptotic activities by proliferation assay, radioimmunoassay, gene transfection, reporter gene analysis and flow cytometry, respectively. Results: A strong stimulatory proliferation effect was observed in hepatocytes, and an inhibitory effect was found in HSCs. Hyaluronic acid (HA) production and reporter gene activities driven by various α1(Ⅰ) procollagen gene promoters in HSC-T6 were significantly decreased after treatment with the extract. Fluo-Anexin V binding apoptotic HepG2 cells were more prominent in the presence of 60 μg/ml extract. More CD4+/CD69+ positive T lymphocytes existed in the presence of the extract. Conclusion: Porcine liver extract is effective for antifibrogenesis via hepatocyte regeneration, HSC and hepatoma cell inhibition in vitro. The elevation of active T lymphocytes is helpful for immune surveillance. Fine mapping of the extract is necessary in order to get definite molecules which are essential in all described functions.

  8. Expression of p53, Bax and Bcl-2 proteins in hepatocytes in non-alcoholic fatty liver disease

    Institute of Scientific and Technical Information of China (English)

    Anatol Panasiuk; Janusz Dzieciol; Bozena Panasiuk; Danuta Prokopowicz

    2006-01-01

    AIM: To analyze the protein expression essential for apoptosis in liver steatosis.METHODS: The expression of proapoptotic proteinsp53, Bax, and antiapoptotic Bcl-2 in hepatocytes with steatosis (SH) and without steatosis (NSH) was evaluated in 84 patients at various stages of non-alcoholic fatty liver disease (NAFLD).RESULTS: Immunohistochemical staining of liver tissue showed the activation of p53 protein in SH and NSH with increased liver steatosis, diminished Bcl-2 and slightly decreased Bax protein. Positive correlation was found between the stage of liver steatosis with p53 expression in SH (r = 0.54, P < 0.01) and NSH (r = 0.49,P < 0.01).The antiapoptotic protein Bcl-2 was diminished together with the advancement of liver steatosis, especially in non-steatosed hepatocytes (r =0.43, P < 001).CONCLUSION: Apoptosis is one of the most important mechanisms leading to hepatocyte elimination in NAFLD. The intensification of inflammation in NAFLD induces proapoptotic protein p53 with the inhibition of antiapoptotic Bcl-2.

  9. [Current status and future perspectives of hepatocyte transplantation].

    Science.gov (United States)

    Pareja, Eugenia; Cortés, Miriam; Gómez-Lechón, M José; Maupoey, Javier; San Juan, Fernando; López, Rafael; Mir, Jose

    2014-02-01

    The imbalance between the number of potential beneficiaries and available organs, originates the search for new therapeutic alternatives, such as Hepatocyte transplantation (HT).Even though this is a treatment option for these patients, the lack of unanimity of criteria regarding indications and technique, different cryopreservation protocols, as well as the different methodology to assess the response to this therapy, highlights the need of a Consensus Conference to standardize criteria and consider future strategies to improve the technique and optimize the results.Our aim is to review and update the current state of hepatocyte transplantation, emphasizing the future research attempting to solve the problems and improve the results of this treatment.

  10. No evidence for protective erythropoietin alpha signalling in rat hepatocytes

    Directory of Open Access Journals (Sweden)

    Frede Stilla

    2009-04-01

    Full Text Available Abstract Background Recombinant human erythropoietin alpha (rHu-EPO has been reported to protect the liver of rats and mice from ischemia-reperfusion injury. However, direct protective effects of rHu-EPO on hepatocytes and the responsible signalling pathways have not yet been described. The aim of the present work was to study the protective effect of rHu-EPO on warm hypoxia-reoxygenation and cold-induced injury to hepatocytes and the rHu-EPO-dependent signalling involved. Methods Loss of viability of isolated rat hepatocytes subjected to hypoxia/reoxygenation or incubated at 4°C followed by rewarming was determined from released lactate dehydrogenase activity in the absence and presence of rHu-EPO (0.2–100 U/ml. Apoptotic nuclear morphology was assessed by fluorescence microscopy using the nuclear fluorophores H33342 and propidium iodide. Erythropoietin receptor (EPOR, EPO and Bcl-2 mRNAs were quantified by real time PCR. Activation of JAK-2, STAT-3 and STAT-5 in hepatocytes and rat livers perfused in situ was assessed by Western blotting. Results In contrast to previous in vivo studies on ischemia-reperfusion injury to the liver, rHu-EPO was without any protective effect on hypoxic injury, hypoxia-reoxygenation injury and cold-induced apoptosis to isolated cultured rat hepatocytes. EPOR mRNA was identified in these cells but specific detection of the EPO receptor protein was not possible due to the lack of antibody specificity. Both, in the cultured rat hepatocytes (10 U/ml for 15 minutes and in the rat liver perfused in situ with rHu-EPO (8.9 U/ml for 15 minutes no evidence for EPO-dependent signalling was found as indicated by missing effects of rHu-EPO on phosphorylation of JAK-2, STAT-3 and STAT-5 and on the induction of Bcl-2 mRNA. Conclusion Together, these results indicate the absence of any protective EPO signalling in rat hepatocytes. This implies that the protection provided by rHu-EPO in vivo against ischemia-reperfusion and

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  9. Fate tracing of mature hepatocytes in mouse liver homeostasis and regeneration.

    Science.gov (United States)

    Malato, Yann; Naqvi, Syed; Schürmann, Nina; Ng, Raymond; Wang, Bruce; Zape, Joan; Kay, Mark A; Grimm, Dirk; Willenbring, Holger

    2011-12-01

    Recent evidence has contradicted the prevailing view that homeostasis and regeneration of the adult liver are mediated by self duplication of lineage-restricted hepatocytes and biliary epithelial cells. These new data suggest that liver progenitor cells do not function solely as a backup system in chronic liver injury; rather, they also produce hepatocytes after acute injury and are in fact the main source of new hepatocytes during normal hepatocyte turnover. In addition, other evidence suggests that hepatocytes are capable of lineage conversion, acting as precursors of biliary epithelial cells during biliary injury. To test these concepts, we generated a hepatocyte fate-tracing model based on timed and specific Cre recombinase expression and marker gene activation in all hepatocytes of adult Rosa26 reporter mice with an adenoassociated viral vector. We found that newly formed hepatocytes derived from preexisting hepatocytes in the normal liver and that liver progenitor cells contributed minimally to acute hepatocyte regeneration. Further, we found no evidence that biliary injury induced conversion of hepatocytes into biliary epithelial cells. These results therefore restore the previously prevailing paradigms of liver homeostasis and regeneration. In addition, our new vector system will be a valuable tool for timed, efficient, and specific loop out of floxed sequences in hepatocytes.

  10. Effect of trifluoperazine on toxicity, HIF-1α induction and hepatocyte regeneration in acetaminophen toxicity in mice

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhuri, Shubhra, E-mail: SCHAUDHURI@uams.edu [Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas (United States); Arkansas Children' s Hospital Research Institute, Little Rock, AR (United States); McCullough, Sandra S., E-mail: mcculloughsandras@uams.edu [Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas (United States); Arkansas Children' s Hospital Research Institute, Little Rock, AR (United States); Hennings, Leah, E-mail: lhennings@uams.edu [Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, Arkansas (United States); Arkansas Children' s Hospital Research Institute, Little Rock, AR (United States); Brown, Aliza T., E-mail: brownalizat@uams.edu [Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas (United States); Arkansas Children' s Hospital Research Institute, Little Rock, AR (United States); Li, Shun-Hwa [Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI (United States); Simpson, Pippa M., E-mail: psimpson@mcw.edu [Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI (United States); Hinson, Jack A., E-mail: hinsonjacka@uams.edu [Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, Arkansas Children' s Hospital Research Institute, Little Rock, AR (United States); James, Laura P., E-mail: jameslaurap@uams.edu [Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas (United States); Arkansas Children' s Hospital Research Institute, Little Rock, AR (United States); Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, Arkansas Children' s Hospital Research Institute, Little Rock, AR (United States)

    2012-10-15

    Oxidative stress and mitochondrial permeability transition (MPT) are important mechanisms in acetaminophen (APAP) toxicity. The MPT inhibitor trifluoperazine (TFP) reduced MPT, oxidative stress, and toxicity in freshly isolated hepatocytes treated with APAP. Since hypoxia inducible factor-one alpha (HIF-1α) is induced very early in APAP toxicity, a role for oxidative stress in the induction has been postulated. In the present study, the effect of TFP on toxicity and HIF-1α induction in B6C3F1 male mice treated with APAP was examined. Mice received TFP (10 mg/kg, oral gavage) prior to APAP (200 mg/kg IP) and at 7 and 36 h after APAP. Measures of metabolism (hepatic glutathione and APAP protein adducts) were comparable in the two groups of mice. Toxicity was decreased in the APAP/TFP mice at 2, 4, and 8 h, compared to the APAP mice. At 24 and 48 h, there were no significant differences in toxicity between the two groups. TFP lowered HIF-1α induction but also reduced the expression of proliferating cell nuclear antigen, a marker of hepatocyte regeneration. TFP can also inhibit phospholipase A{sub 2}, and cytosolic and secretory PLA{sub 2} activity levels were reduced in the APAP/TFP mice compared to the APAP mice. TFP also lowered prostaglandin E{sub 2} expression, a known mechanism of cytoprotection. In summary, the MPT inhibitor TFP delayed the onset of toxicity and lowered HIF-1α induction in APAP treated mice. TFP also reduced PGE{sub 2} expression and hepatocyte regeneration, likely through a mechanism involving PLA{sub 2}. -- Highlights: ► Trifluoperazine reduced acetaminophen toxicity and lowered HIF-1α induction. ► Trifluoperazine had no effect on the metabolism of acetaminophen. ► Trifluoperazine reduced hepatocyte regeneration. ► Trifluoperazine reduced phospholipase A{sub 2} activity and prostaglandin E{sub 2} levels.

  11. MiR-21 simultaneously regulates ERK1 signaling in HSC activation and hepatocyte EMT in hepatic fibrosis.

    Directory of Open Access Journals (Sweden)

    Juan Zhao

    Full Text Available BACKGROUND: MicroRNA-21 (miR-21 plays an important role in the pathogenesis and progression of liver fibrosis. Here, we determined the serum and hepatic content of miR-21 in patients with liver cirrhosis and rats with dimethylnitrosamine-induced hepatic cirrhosis and examined the effects of miR-21 on SPRY2 and HNF4α in modulating ERK1 signaling in hepatic stellate cells (HSCs and epithelial-mesenchymal transition (EMT of hepatocytes. METHODS: Quantitative RT-PCR was used to determine miR-21 and the expression of SPRY2, HNF4α and other genes. Immunoblotting assay was carried out to examine the expression of relevant proteins. Luciferase reporter assay was performed to assess the effects of miR-21 on its predicted target genes SPRY2 and HNF4α. Primary HSCs and hepatocytes were treated with miR-21 mimics/inhibitors or appropriate adenoviral vectors to examine the relation between miR-21 and SPRY2 or HNF4α. RESULTS: The serum and hepatic content of miR-21 was significantly higher in cirrhotic patients and rats. SPRY2 and HNF4α mRNA levels were markedly lower in the cirrhotic liver. MiR-21 overexpression was associated with enhanced ERK1 signaling and EMT in liver fibrosis. Luciferase assay revealed suppressed SPRY2 and HNF4α expression by miR-21. Ectopic miR-21 stimulated ERK1 signaling in HSCs and induced hepatocyte EMT by targeting SPRY2 or HNF4α. Downregulating miR-21 suppressed ERK1 signaling, inhibited HSC activation, and blocked EMT in TGFβ1-treated hepatocytes. CONCLUSIONS: MiR-21 modulates ERK1 signaling and EMT in liver fibrosis by regulating SPRY2 and HNF4α expression. MiR-21 may serve as a potentially biomarker as well as intervention target for hepatic cirrhosis.

  12. Triglyceride accumulation in long-term cultures of adult rat hepatocytes by chronic exposure to Aroclor 1254.

    Science.gov (United States)

    Mendoza-Figueroa, T; Hernández, A; López, M L

    1989-01-01

    The effect of chronic exposure to micromolar concentrations of Aroclor 1254 (Aro) on the hepatic lipid metabolism was studied in long-term cultures of adult rat hepatocytes. Hepatocytes were cocultivated with mitomycin C-treated 3T3 cells and exposed for 2 wk to Aroclor 1254 concentrations ranging from 0.01 to 20 micrograms/ml. The Aro-exposed cultures showed intracytoplasmic lipid droplets and a maximum increase of 55% in the triglyceride (TG) content and of 4.4-fold in the cytochrome P-450 content. Labeling studies with [14C]acetic and [14C]oleic acid showed no changes in the uptake of fatty acid and TG precursors by the Aro-treated cultures; the synthesis of cellular lipids from [14C]acetic acid was slightly inhibited by Aroclor 1254, but that from [14C]oleic acid was increased, specially for TG (37%). The secretion of total lipids and TG was 2.1- and 2.7-fold lower, respectively, in the cultures treated with 20 micrograms/ml of Aroclor 1254, resulting in an increase of 1.9-fold in the intracellular content of TG. The synthesis of cellular proteins labeled with [3H]leucine was unchanged in the Aro-treated cultures, but the secretion of exportable proteins was 1.7-fold lower in the cultures treated with 20 micrograms/ml of Aroclor 1254. Our results showed that long-term exposure to in vivo relevant concentrations of Aroclor 1254 produced morphological and biochemical changes in cultured hepatocytes, like those described in vivo, and intracellular TG accumulation due mostly to impaired secretion of TG by the hepatocytes. Our results also suggest that this culture system could be useful for the screening of toxic agents producing fatty liver and the study of the involved mechanism(s).

  13. Triglyceride accumulation in long-term cultures of adult rat hepatocytes by chronic exposure to Aroclor 1254

    Energy Technology Data Exchange (ETDEWEB)

    Mendoza-Figueroa, T.; Hernandez, A.; de Lourdes Lopez, M. (Instituto Politecnico Nacional, Mexico City (Mexico))

    1989-01-01

    The effect of chronic exposure to micromolar concentrations of Aroclor 1254 (Aro) on the hepatic lipid metabolism was studied in long-term cultures of adult rat hepatocytes. Hepatocytes were cocultivated with mytomicin C-treated 3T3 cells and exposed for 2 wk to Aroclor 1254 concentrations ranging from 0.01 to 20 {mu}g/ml. The Aro-exposed cultures showed intracytoplasmic lipid droplets and a maximum increase of 55% in the triglyceride (TG) content and of 4.4-fold in the cytochrome P-450 content. Labeling studies with ({sup 14}C)acetic and ({sup 14}C)oleic acid showed no changes in the uptake of fatty acid and TG precursors by the Aro-treated cultures; the synthesis of cellular lipids from ({sup 14}C)acetic acid was slightly inhibited by Aroclor 1254, but that from ({sup 14}C)oleic acid was increased, specially for TF (37%). The secretion of total lipids and TG was 2.1- and 2.7-fold lower, respectively, in the cultures treated with 20 {mu}g/ml of Aroclor 1254, resulting in an increase of 1.9-fold in the intracellular content of TG. The synthesis of cellular proteins labeled with ({sup 3}H)leucine was unchanged in the Aro-treated cultures, but the secretion of exportable proteins was 1.7-fold lower in the cultures treated with 20 {mu}g/ml of Aroclor 1254. Our results showed that long-term exposure to in vivo relevant concentrations of Aroclor 1254 produced morphological and biochemical changes in cultured hepatocytes, like those described in vivo, and intracellular TG accumulation due mostly to impaired secretion of TG by the hepatocytes. Our results also suggest that this culture system could be useful for the screening of toxic agents producing fatty liver and the study of the involved mechanism(s).

  14. Effect of rapeseed oil and dietary n-3 fatty acids on triacylglycerol synthesis and secretion in Atlantic salmon hepatocytes.

    Science.gov (United States)

    Kjaer, M A; Vegusdal, A; Gjøen, T; Rustan, A C; Todorcević, M; Ruyter, B

    2008-03-01

    Fish oil (FO) has traditionally been used as the dominating lipid component in fish feed. However, FO is a limited resource and the price varies considerably, which has led to an interest in using alternative oils, such as vegetable oils (VOs), in fish diets. It is far from clear how these VOs affect liver lipid secretion and fish health. The polyunsaturated fatty acids (PUFAs), eicosapentanoic acid (EPA) and docosahexanioc acid (DHA), reduce the secretion of lipoproteins rich in triacylglycerols (TAGs) in Atlantic salmon, as they do in humans. The mechanism by which n-3 fatty acids (FAs) in the diet reduce TAG secretion is not known. We have therefore investigated the effects of rapeseed oil (RO) and n-3 rich diets on the accumulation and secretion of (3)H-glycerolipids by salmon hepatocytes. Salmon, of approximately 90 g were fed for 17 weeks on one of four diets supplemented with either 13.5% FO, RO, EPA-enriched oil or DHA-enriched oil until a final average weight of 310 g. Our results show that the dietary FA composition markedly influences the endogenous FA composition and lipid content of the hepatocytes. The intracellular lipid level in hepatocytes from fish fed RO diet and DHA diet were higher, and the expressions of the genes for microsomal transfer protein (MTP) and apolipoprotein A1 (Apo A1) were lower, than those in fish fed the two other diets. Secretion of hepatocyte glycerolipids was lower in fish fed the EPA diet and DHA diet than it was in fish fed the RO diet. Our results indicate that EPA and DHA possess different hypolipidemic properties. Both EPA and DHA inhibit TAG synthesis and secretion, but only EPA induces mitochondrial proliferation and reduce intracellular lipid. Expression of the gene for peroxisome proliferator-activated receptor alpha (PPARalpha) was higher in the DHA dietary group than it was in the other groups.

  15. TGFbeta induces apoptosis and EMT in primary mouse hepatocytes independently of p53, p21Cip1 or Rb status

    Directory of Open Access Journals (Sweden)

    Harrison David J

    2008-07-01

    Full Text Available Abstract Background TGFβ has pleiotropic effects that range from regulation of proliferation and apoptosis to morphological changes and epithelial-mesenchymal transition (EMT. Some evidence suggests that these effects may be interconnected. We have recently reported that P53, P21Cip1 and pRB, three critical regulators of the G1/S transition are variably involved in TGFβ-induced cell cycle arrest in hepatocytes. As these proteins are also involved in the regulation of apoptosis in many circumstances, we investigated their contribution to other relevant TGFβ-induced effects, namely apoptosis and EMT, and examined how the various processes were interrelated. Methods Primary mouse hepatocytes deficient in p53, p21 and/or Rb, singly or in combination were treated with TGFβ for 24 to 96 hours. Apoptosis was quantified according to morphology and by immunostaining for cleaved-capsase 3. Epithelial and mesenchymal marker expression was studied using immunocytochemistry and real time PCR. Results We found that TGFβ similarly induced morphological changes regardless of genotype and independently of proliferation index or sensitivity to inhibition of proliferation by TGFβ. Morphological changes were accompanied by decrease in E-cadherin and increased Snail expression but the mesenchymal markers (N-cadherin, SMAα and Vimentin studied remained unchanged. TGFβ induced high levels of apoptosis in p53-/-, Rb-/-, p21cip1-/- and control hepatocytes although with slight differences in kinetics. This was unrelated to proliferation or changes in morphology and loss of cell-cell adhesion. However, hepatocytes deficient in both p53 and p21cip1were less sensitive to TGFβ-induced apoptosis. Conclusion Although p53, p21Cip1 and pRb are well known regulators of both proliferation and apoptosis in response to a multitude of stresses, we conclude that they are critical for TGFβ-driven inhibition of hepatocytes proliferation, but only slightly modulate TGF

  16. Influence of adenovirus vector-mediated RNAi on expression of c-Met in SK-BR-3 cells%腺病毒载体介导的RNAi对SK-BR-3细胞c-Met表达的影响

    Institute of Scientific and Technical Information of China (English)

    赵慧; 陈东; 袁振华; 王忠山; 吴小兵

    2006-01-01

    目的:通过腺病毒载体介导的RNA干扰技术抑制乳腺癌细胞HGF受体c-Met的表达,抑制乳腺癌细胞增殖、诱导细胞凋亡.方法:PCR法获得人U6启动子及带有c-Met反向互补靶序列的片段HU6shmet;利用腺病毒载体将其传递至SK-BR-3细胞;RNA狭缝杂交检测SK-BR-3细胞c-Met mRNA水平,Western印迹检测c-Met蛋白水平.结果:获得了带有人U6启动子及c-Met反向互补靶序列的重组腺病毒载体rAdUshmet1和rAdUshmet2.转导了重组腺病毒的SK-BR-3细胞的c-Met mRNA和蛋白相对表达量均有所下降.结论:腺病毒载体rAdUshmet通过抑制HGF受体c-Met表达,能在一定程度上阻断HGF-c-Met信号转导通路,有可能成为对乳腺癌进行基因治疗的有效载体.

  17. Hierarchical targeted hepatocyte mitochondrial multifunctional chitosan nanoparticles for anticancer drug delivery.

    Science.gov (United States)

    Chen, Zhipeng; Zhang, Liujie; Song, Yang; He, Jiayu; Wu, Li; Zhao, Can; Xiao, Yanyu; Li, Wei; Cai, Baochang; Cheng, Haibo; Li, Weidong

    2015-06-01

    The overwhelming majority of drugs exert their pharmacological effects after reaching their target sites of action, however, these target sites are mainly located in the cytosol or intracellular organelles. Consequently, delivering drugs to the specific organelle is the key to achieve maximum therapeutic effects and minimum side-effects. In the work reported here, we designed, synthesized, and evaluated a novel mitochondrial-targeted multifunctional nanoparticles (MNPs) based on chitosan derivatives according to the physiological environment of the tumor and the requirement of mitochondrial targeting drug delivery. The intelligent chitosan nanoparticles possess various functions such as stealth, hepatocyte targeting, multistage pH-response, lysosomal escape and mitochondrial targeting, which lead to targeted drug release after the progressively shedding of functional groups, thus realize the efficient intracellular delivery and mitochondrial localization, inhibit the growth of tumor, elevate the antitumor efficacy, and reduce the toxicity of anticancer drugs. It provides a safe and efficient nanocarrier platform for mitochondria targeting anticancer drug delivery.

  18. Inhibitory effect of picroside Ⅱ on hepatocyte apoptosis

    Institute of Scientific and Technical Information of China (English)

    Hua GAO; Ya-wei ZHOU

    2005-01-01

    Aim: To investigate the influence of picroside Ⅱ on hepatocyte apoptosis and its mechanism. Methods: Morphological changes and quantification of apoptotic cells were determined under transmission electron microscopy and flow cytometry respectively. DNA fragmentation was visualized by agarose gel electrophoresis.Semi-quantitative reverse transcription-PCR (RT-PCR) was used to analyze the expression of bcl-2 and bax genes. The content of manganese-superoxide dismutase (SOD) in liver mitochondria was detected by the Marland method. The content of malonic aldehyde (MDA) and the protein level in liver tissue were determined by thiobarbituric acid colorimetry and Lowry method. Results:Picroside Ⅱ decreased the levels of alanine aminotransferase and aspartate aminotransferase in the serum resulting from acute-liver injured mice induced with D-GalN and LPS; it also reduced the content of MDA, and thus, enhanced the activity of SOD. Picroside Ⅱ 10 mg/kg was found to protect hepatocytes against apoptosis in a dose-dependent manner; it up-regulated the expression of bcl-2 genes,thus increased the bcl-2/bax ratio. Conclusion: Picroside Ⅱ can protect hepatocytes against injury and prevent hepatocytes from apoptosis. It might by upregulating the bcl-2 gene expression and antioxidation.

  19. Effect of matrine on primary human hepatocytes in vitro.

    Science.gov (United States)

    Gong, Xiaobing; Gao, Yuan; Guo, Guoqing; Vondran, Florian W R; Schwartlander, Ruth; Efimova, Ekaterina; Pless, Gesine; Sauera, Igor M; Neuhaus, Peter

    2015-03-01

    Matrine is a bioactive component of the traditional Chinese medical herb Sophora flavescens that has been used in China to treat various kinds of diseases including virus hepatitis. However, the molecular mechanisms underlying its hepatoprotective effects remains elusive. In the present study, primary human hepatocytes were employed to elucidate the protective effects and molecular mechanisms of matrine. We observed that low concentrations of matrine had no significant impact on albumin secretion, but high concentrations (>140 mg/L) of matrine decreased the albumin secretion in hepatocytes. Western blot data indicated that matrine at 140 mg/L at 72 h induced protein expression of CYP2A6, CYP2B6 and CYP3A4. Furthermore, high concentrations of matrine reduced LDH and AST levels and were cytotoxic to hepatocytes, leading to a decreased cell viability and total protein amount. Moreover, low concentrations of matrine, enhanced the ECOD activity and decreased the level of NO2 (-) induced by cytokines in human hepatocytes. Taken together, the present study sheds novel light on the molecular mechanisms of matrine and potential application of matrine in hepatic diseases.

  20. A Microfabricated Platform for Generating Physiologically-Relevant Hepatocyte Zonation

    Science.gov (United States)

    McCarty, William J.; Usta, O. Berk; Yarmush, Martin L.

    2016-05-01

    In vitro liver models have been important tools for more than 40 years for academic research and preclinical toxicity screening by the pharmaceutical industry. Hepatocytes, the highly metabolic parenchymal cells of the liver, are efficient at different metabolic chemistries depending on their relative spatial location along the sinusoid from the portal triad to the central vein. Although replicating hepatocyte metabolic zonation is vitally important for physiologically-relevant in vitro liver tissue and organ models, it is most often completely overlooked. Here, we demonstrate the creation of spatially-controlled zonation across multiple hepatocyte metabolism levels through the application of precise concentration gradients of exogenous hormone (insulin and glucagon) and chemical (3-methylcholanthrene) induction agents in a microfluidic device. Observed gradients in glycogen storage via periodic acid-Schiff staining, urea production via carbamoyl phosphatase synthetase I staining, and cell viability after exposure to allyl alcohol and acetaminophen demonstrated the in vitro creation of hepatocyte carbohydrate, nitrogen, alcohol degradation, and drug conjugation metabolic zonation. This type of advanced control system will be crucial for studies evaluating drug metabolism and toxicology using in vitro constructs.

  1. Asialoglycoprotein receptor mediated hepatocyte targeting - strategies and applications.

    Science.gov (United States)

    D'Souza, Anisha A; Devarajan, Padma V

    2015-04-10

    Hepatocyte resident afflictions continue to affect the human population unabated. The asialoglycoprotein receptor (ASGPR) is primarily expressed on hepatocytes and minimally on extra-hepatic cells. This makes it specifically attractive for receptor-mediated drug delivery with minimum concerns of toxicity. ASGPR facilitates internalization by clathrin-mediated endocytosis and exhibits high affinity for carbohydrates specifically galactose, N-acetylgalactosamine and glucose. Isomeric forms of sugar, galactose density and branching, spatial geometry and galactose linkages are key factors influencing ligand-receptor binding. Popular ligands for ASGPR mediated targeting are carbohydrate polymers, arabinogalactan and pullulan. Other ligands include galactose-bearing glycoproteins, glycopeptides and galactose modified polymers and lipids. Drug-ligand conjugates provide a viable strategy; nevertheless ligand-anchored nanocarriers provide an attractive option for ASGPR targeted delivery and are widely explored. The present review details various ligands and nanocarriers exploited for ASGPR mediated delivery of drugs to hepatocytes. Nanocarrier properties affecting ASGPR mediated uptake are discussed at length. The review also highlights the clinical relevance of ASGPR mediated targeting and applications in diagnostics. ASGPR mediated hepatocyte targeting provides great promise for improved therapy of hepatic afflictions.

  2. 3D Cultivation Techniques for Primary Human Hepatocytes

    Directory of Open Access Journals (Sweden)

    Anastasia Bachmann

    2015-02-01

    Full Text Available One of the main challenges in drug development is the prediction of in vivo toxicity based on in vitro data. The standard cultivation system for primary human hepatocytes is based on monolayer cultures, even if it is known that these conditions result in a loss of hepatocyte morphology and of liver-specific functions, such as drug-metabolizing enzymes and transporters. As it has been demonstrated that hepatocytes embedded between two sheets of collagen maintain their function, various hydrogels and scaffolds for the 3D cultivation of hepatocytes have been developed. To further improve or maintain hepatic functions, 3D cultivation has been combined with perfusion. In this manuscript, we discuss the benefits and drawbacks of different 3D microfluidic devices. For most systems that are currently available, the main issues are the requirement of large cell numbers, the low throughput, and expensive equipment, which render these devices unattractive for research and the drug-developing industry. A higher acceptance of these devices could be achieved by their simplification and their compatibility with high-throughput, as both aspects are of major importance for a user-friendly device.

  3. Transplantation of human hepatocytes into tolerized genetically immunocompetent rats

    Institute of Scientific and Technical Information of China (English)

    Edwin C. Ouyang; Catherine H. Wu; Cherie Walton; Kittichai Promrat; George Y. Wu

    2001-01-01

    AIM To determine whether normal geneticallyirnmunocornpetent rodent hosts could bemanipulated to accept human hepatocytetransplants with long term survival withoutirnrnunosuppression.METHODS Tolerance towards humanhepatocytes was established by injection ofprimary human hepatocytes or Huh7 humanhepatoma cells into the peritoneal cavities offetal rats. Corresponding cells weresubsequently transplanted into newborn rats viaintrasplenic injection within 24 h after birth.RESULTS Mixed lymphocyte assays showedthat spleen cells from non-tolerized rats werestimulated to proliferate when exposed to humanhepatocytes, while cells from tolerized ratswere not. Injections made between 15 d and 17 dof gestation produced optimal tolerizaton.Transplanted human hepatocytes in rat liverswere visualized by immunohistochemicalstaining of human albumin. By dot blotting ofgenomic DNA in livers of tolerized rats 16 weeksafter hepatocyte transplantation, it was foundthat approximately 2.5 × 105 human hepatocytessurvived per rat liver. Human albumin mRNA wasdetected in rat livers by RT-PCR for 15 wk, andhuman albumin protein was also detectable in ratserum.CONCLUSION Tolerization of an immuno-competent rat can permit transplantation, andsurvival of functional human hepatocytes.

  4. Mesenchymal stem cells support hepatocyte function in engineered liver grafts.

    Science.gov (United States)

    Kadota, Yoshie; Yagi, Hiroshi; Inomata, Kenta; Matsubara, Kentaro; Hibi, Taizo; Abe, Yuta; Kitago, Minoru; Shinoda, Masahiro; Obara, Hideaki; Itano, Osamu; Kitagawa, Yuko

    2014-01-01

    Recent studies suggest that organ decellularization is a promising approach to facilitate the clinical application of regenerative therapy by providing a platform for organ engineering. This unique strategy uses native matrices to act as a reservoir for the functional cells which may show therapeutic potential when implanted into the body. Appropriate cell sources for artificial livers have been debated for some time. The desired cell type in artificial livers is primary hepatocytes, but in addition, other supportive cells may facilitate this stem cell technology. In this context, the use of mesenchymal stem cells (MSC) is an option meeting the criteria for therapeutic organ engineering. Ideally, supportive cells are required to (1) reduce the hepatic cell mass needed in an engineered liver by enhancing hepatocyte function, (2) modulate hepatic regeneration in a paracrine fashion or by direct contact, and (3) enhance the preservability of parenchymal cells during storage. Here, we describe enhanced hepatic function achieved using a strategy of sequential infusion of cells and illustrate the advantages of co-cultivating bone marrow-derived MSCs with primary hepatocytes in the engineered whole-liver scaffold. These co-recellularized liver scaffolds colonized by MSCs and hepatocytes were transplanted into live animals. After blood flow was established, we show that expression of adhesion molecules and proangiogenic factors was upregulated in the graft.

  5. The use of pig hepatocytes for biotransformation and toxicity studies.

    NARCIS (Netherlands)

    Hoogenboom, L.A.P.

    1991-01-01

    The three main objectives of this study were, (1) to investigate the possibility to isolate viable hepatocytes from liver samples of pigs, (2) to study their use for biotransformation and toxicity studies, and (3) to demonstrate the value of this model, in particular in the field of residue toxicolo

  6. Metformin stimulates FGF21 expression in primary hepatocytes

    DEFF Research Database (Denmark)

    Nygaard, Eva B; Vienberg, Sara G; Ørskov, Cathrine

    2012-01-01

    incubated with Compound C (an AMPK inhibitor) in the presence of metformin. A strong dose-dependent increase in FGF21 expression was observed in both rat and human hepatocytes treated with metformin. This effect was blocked by addition of the AMPK-inhibitor Compound C. The study shows that metformin...

  7. Stem cell-derived hepatocytes and their use in toxicology.

    Science.gov (United States)

    Guguen-Guillouzo, Christiane; Corlu, Anne; Guillouzo, Andre

    2010-03-30

    Better prediction of safety risk and understanding of mechanism of action of drug candidates remain a major challenge in order to prevent late stage attrition. Continuous efforts are made to improve and develop new models, especially in some areas such as hepatotoxicity. Besides primary hepatocytes and transformed liver cell lines, stem cells either isolated from embryos or adult tissues or obtained by reprogramming somatic cells are emerging as a new potential source of unlimited numbers of hepatocytes. Presently, only hepatocyte-like cells expressing low levels of liver-specific markers, especially drug metabolizing and detoxifying enzymes, are usually obtained, making them still unsuitable as metabolically competent cells for toxicity studies. The only exceptions are some hepatoma cell lines, particularly the HepaRG cell line that can differentiate from a bipotent progenitor stage to attain the functional capacity of normal adult hepatocytes in primary culture without losing the indefinite growth property of transformed cells. Since the research field on stem cells is growing fast marked advances might be expected in the next future.

  8. Preservation of hepatocyte suspensions at 4 degrees C.

    Science.gov (United States)

    Lund, P; Wiggins, D

    1988-10-01

    Suspensions of rat hepatocytes are resistant to hypoxia for at least 24 hr at 4 degrees C. After storage for 24 hr with xylitol, sorbitol, or glycerol, their subsequent capacity for glucogenesis from these substrates is increased. Even storage under N2/CO2 as the gas phase has little deleterious effect.

  9. Aniline Induces Oxidative Stress and Apoptosis of Primary Cultured Hepatocytes

    Directory of Open Access Journals (Sweden)

    Yue Wang

    2016-11-01

    Full Text Available The toxicity and carcinogenicity of aniline in humans and animals have been well documented. However, the molecular mechanism involved in aniline-induced liver toxicity and carcinogenesis remains unclear. In our research, primary cultured hepatocytes were exposed to aniline (0, 1.25, 2.50, 5.0 and 10.0 μg/mL for 24 h in the presence or absence of N-acetyl-l-cysteine (NAC. Levels of reactive oxygen species (ROS, malondialdehyde (MDA, and glutathione (GSH, activities of superoxide dismutase (SOD and catalase (CAT, mitochondrial membrane potential, DNA damage, cell viability, and apoptosis were detected. Levels of ROS and MDA were significantly increased and levels of GSH and CAT, activity of SOD, and mitochondrial membrane potential in hepatocytes were significantly decreased by aniline compared with the negative control group. The tail moment and DNA content of the tail in exposed groups were significantly higher than those in the negative control group. Cell viability was reduced and apoptotic death was induced by aniline in a concentration-dependent manner. The phenomena of ROS generation, oxidative damage, loss of mitochondrial membrane potential, DNA damage and apoptosis could be prevented if ROS inhibitor NAC was added. ROS generation is involved in the loss of mitochondrial membrane potential and DNA injury, which may play a role in aniline-induced apoptosis in hepatocytes. Our study provides insight into the mechanism of aniline-induced toxicity and apoptosis of hepatocytes.

  10. Toluene metabolism in isolated rat hepatocytes: effects of in vivo pretreatment with acetone and phenobarbital

    Energy Technology Data Exchange (ETDEWEB)

    Smith-Kielland, A.; Ripel, A. (National Inst. of Forensic Toxicology, Oslo (Norway))

    1993-02-01

    Hepatocytes isolated from control, acetone- and phenobarbital-pretreated rats were used to study the metabolic conversion of toluene to benzyl alcohol, benzaldehyde, benzoic acid and hippuric acid at low (<100 [mu]M) and high (100-500 [mu]M) toluene concentrations. The baseline formation rates of toluene metabolites (benzyl alcohol, benzoic acid and hippuric acid) were 2.9[+-]1.7 and 10.0[+-]2.3 nmol/mg cell protein/60 min at low and high toluene concentrations, respectively. In vivo pretreatment of rats with acetone and phenobarbital increased the formation of metabolites: at low toluene concentrations 3- and 5-fold, respectively; at high toluene concentrations no significant increase (acetone) and 8-fold increase (phenobarbital). Apparent inhibition by ethanol, 7 and 60 mM, was most prominent at low toluene concentrations: 63% and 69%, respectively, in control cells; 84% and 91% in acetone-pretreated cells, and 32% (not significant) and 51% in phenobarbital-pretreated cells. Ethanol also caused accumulation of benzyl alcohol. The apparent inhibition by isoniazid was similar to that of ethanol at low toluene concentrations. Control and acetone-pretreated cells were apparently resistant towards metyrapone; the decrease was 49% and 64% in phenobarbital-pretreated cells at low and high toluene concentrations, respectively. In these cells, the decrease in presence of combined ethanol and metyrapone was 95% (low toluene concentrations). 4-Methylpyrazole decreased metabolite formation extensively in all groups. Benzaldehyde was only found in the presence of an aldehyde dehydrogenase inhibitor. Increased ratio benzoic/hippuric acid was observed at high toluene concentrations. These results demonstrate that toluene oxidation may be studied by product formation in isolated hepatocytes. However, the influence of various enzymes in the overall metabolism could not be ascertained due to lack of inhibitor specificity. (orig.).

  11. alpha-Asarone toxicity in long-term cultures of adult rat hepatocytes.

    Science.gov (United States)

    López, M L; Hernández, A; Chamorro, G; Mendoza-Figueroa, T

    1993-04-01

    In this work we studied the toxic effects of alpha-asarone, a hypolipidemic active principle of Guatteria gaumeri Greenman, on long-term cultures of adult rat hepatocytes cultivated on a feeder layer of 3T3 cells. The exposure for one and two weeks to alpha-asarone (1-50 micrograms/ml) produced intracytoplasmic lipid droplets and at higher concentrations (25-50 micrograms/ml) retraction of the hepatocyte cords and cell detachment. Ultrastructurally, the treated cultures (10 micrograms/ml) showed enlargement and vacuolization of the mitochondria in addition to lipid droplets. The triacylglycerol content increased up to 2.3-fold in the cultures treated for one week with 50 micrograms/ml, whereas the protein content per culture, a rough estimate of cell number and viability, decreased by up to 53% in the cultures treated for two weeks with 50 micrograms/ml. The synthesis and secretion of proteins, measured by the incorporation of [3H]-leucine into cellular and secreted macromolecules, decreased also in the cultures exposed. After one and two week exposure to 50 micrograms/ml of alpha-asarone, the secretion of labeled proteins decreased by 53 and 67%, respectively, whereas the synthesis of cellular and total proteins decreased by 48-67%, respectively. The secretion of proteins was the most sensitive parameter of alpha-asarone toxicity. The mean inhibitory dose (ID50), i.e, that producing 50% inhibition in the incorporation of the labeled precursor, was 22.12 and 5.04 micrograms/ml after one and two weeks exposure, respectively. Our results show that long-term exposure to micromolar concentrations of alpha-asarone produces morphologic and ultrastructural alterations, triacylglycerol accumulation (fatty liver), and inhibition of protein synthesis and secretion.(ABSTRACT TRUNCATED AT 250 WORDS)

  12. Effects of 2-APB on Store-operated Ca2+ Channel Currents of Hepatocytes after Hepatic Ischemia/Reperfusion Injury in Rats

    Institute of Scientific and Technical Information of China (English)

    HUANG Changzhou; ZHANG Zongming; QIU Fazu

    2005-01-01

    The effects of hepatic ischemia/reperfusion (I/R) injuries on hepatocellular viability and store-operated calcium current (Isoc) in isolated rat hepatocytes and the effects of 2-APB on storeoperated calcium current (Isoc) in isolated rat hepatocytes after hepaticischemia/reperfusion injuries were studied. Hepatic ischemia and reperfusion injury model was established and whole cell patch-clamp techniques were used to investigate the effects of 2-APB on Isoc. The results showed that ischemia/reperfusion injuries could significantly reduce hepatocellular viability and further increase Isoc in hepatocytes and 2-APB (20, 40, 60, 80, 100 μmol/L) produced a concentration-dependent decrease of Isoc with IC50 value of 64.63±10.56 μmol/L (n= 8). It was concluded that ischemia/reperfusion injuries could reduce hepatocellular viability, probably through increased Isoc in hepatocytes and 2-APB had a protective effect on ischemia/reperfusion-induced liver injury, probably though inhibiting Isoc.

  13. Application of a higher throughput approach to derive apparent Michaelis-Menten constants of isoform-selective p450-mediated biotransformation reactions in human hepatocytes.

    Science.gov (United States)

    Li, Albert P; Schlicht, Kari E

    2014-01-01

    A higher throughput platform was developed for the determination of K(M) values for isoformselective P450 substrates in human hepatocytes via incubation of the hepatocytes with substrates in 384- well plates and metabolite quantification by RapidFire™ mass spectrometry. Isoform-selective P450 substrates were incubated at 8 concentrations in triplicate with cryopreserved human hepatocytes from 16 donors. The metabolic pathways examined were the CYP1A2-catalyzed tacrine 1-hydroxylation, CYP2B6-catalyzed bupropion hydroxylation, CYP2C8-catalyzed amodiaquine N-deethylation, CYP2C9- catalyzed diclofenac 4'-hydroxylation, CYP2D6-catalyzed dextromethorphan O-demethylation, and CYP3A4-catalyzed midazolam 1'-hydroxylation. Typical saturation enzyme kinetics was observed for all the pathways evaluated. Individual differences in the apparent V(max) and K(M) values were observed among the human hepatocytes from each of the 16 individual donors, with no statistically significant gender- or age-associated differences. A "composite" K(M) value was calculated for each of the pathways via normalizing the individual activities to their respective V(max) values to develop "relative activities" followed by Michaelis-Menten analysis of the mean relative activities of the 16 donors at each of the 8 substrate concentrations. The resulting "composite" K(M) values for the P450 substrates may be used to guide in vitro P450 inhibition and induction studies and kinetic modeling of in vivo drug-drug interaction.

  14. Bufalin reverses hepatocyte growth factor-induced resistance to afatinib in H1975 lung cancer cells%蟾毒灵对肝细胞生长因子诱导阿法替尼耐药的逆转作用

    Institute of Scientific and Technical Information of China (English)

    康小红; 路平; 崔艳慧; 王颖; 张清琴; 龚亚斌; 徐振晔

    2015-01-01

    及阻止EMT进程有关。%Objective To investigate the effects of bufalin in reversing hepatocyte growth factor ( HGF)⁃induced resistance to afatinib in H1975 lung cancer cells, and explore its possible mechanism. Methods The afatinib⁃resistant H1975 lung cancer cells ( H1975AR) were induced by exogenous HGF and transfected with recombinant adenoviral vector Ad⁃HGF⁃GFP. The cytostatic effects of bufalin, afatinib and bufalin plus afatinib on H1975AR cells were evaluated by MTT assay. The impact of combined therapy with bufalin and afatinib on invasion of H1975AR cells was determined by transwell migration assay. The concentrations of HGF in the culture supernatants of H1975/Vec and H1975/HGF cells were determined by ELISA. The expression of EGFR, cMET and EMT signal pathway⁃related proteins in H1975AR cells treated with bufalin, afatinib and bufalin plus afatinib were detected by Western blot. Results The results of MTT assay showed that afatinib did not inhibit the growth of H1975 cells, but after 72 h of the combined treatment with bufalin and afatinib and in the presence of HGF, the growth rate of H1975 cells was (38.67±8.76)%, significantly lower than the growth rate of (63.45±12.65)% in the H1975 cells treated with HGF alone (P<0.05) . The results of transwell migration assay showed that in the presence of HGF, afatinib plus bufalin combination therapy markedly decreased the number of invaded H1975 cells through the Matrigel chamber (48.98±11.43), significantly lower than the 118.92±37.29 of afatinib⁃treated or the 88.84±19.53 of bufalin⁃treated cells (P<0.05 for all). The result of ELISA showed that H1975/HGF cells secreted high levels of HGF, and afatinib and bufalin had no effect on the HGF secretion in H1975/HGF cells. The results of Western blot analysis showed that the expression of p⁃EGFR, p⁃cMet, p⁃AKT, p⁃ERK, vimentin and snail in H1975AR cells treated with bufalin puls afatinb was down⁃regulated markedly, and the expression of E⁃cadherin was up

  15. Reduction in porphyrin excretion as a sensitive indicator of lead toxicity in primary cultures of adult rat hepatocytes.

    Science.gov (United States)

    Quintanilla-Vega, B; Hernandez, A; Mendoza-Figueroa, T

    1996-12-01

    Alterations of specific metabolic pathways can be used as sensitive indicators of toxicity by chemicals and can give valuable information on the mechanism(s) involved. Short-term effects of lead on hepatic haem biosynthesis were studied in an in vitro system. Primary cultures of adult rat hepatocytes were exposed for 24-48 hr to lead (0.024-3.6 mm), and excreted and intracellular porphyrins were measured in untreated and lead-treated cultures. Cytotoxicity, as estimated by enzyme leakage, and morphological alterations were also evaluated. Control hepatocytes produced porphyrins at a rate of 387 pmol/mg cellular protein/day. Most of the released and intracellular porphyrins were protoporphyrins, although uro- and coproporphyrins were also detected in lower amounts. After 24 hr of exposure to 0.1-3.6 mm Pb(2+) , excreted porphyrins decreased by 24-92% and intracellular porphyrins by 36-60%, while 48 hr of exposure to 0.024-3.6 mm Pb(2+) caused a progressive reduction of 77-97% in porphyrin excretion and of 49-67% in intracellular porphyrins. Lead exposure also produced a differential decrease of proto-, copro- and uro-porphyrin excretion. These lead effects can be explained mainly by inhibition of the enzyme 5-aminolaevulinate dehydratase, resulting in a decreased monopyrrole supply for porphyrin biosynthesis, and probably by inhibition of the enzyme uroporphyrinogen decarboxylase. Morphological alterations and enzyme leakage were detected only after 24 hr of exposure to 2.4 mm and 48 hr of exposure to 3.6 mm Pb(2+), respectively. The results show that changes in porphyrin production, and particularly in their excretion, in cultured rat hepatocytes are useful indicators of lead toxicity, since they are more sensitive than enzyme leakage and can give preliminary information on the enzyme(s) that could be affected. They also suggest the potential benefits of the use of this method for the evaluation of compounds that alter haem biosynthesis.

  16. Investigation of the role of sigma1-receptors in inositol 1,4,5-trisphosphate dependent calcium signaling in hepatocytes.

    Science.gov (United States)

    Abou-Lovergne, A; Collado-Hilly, M; Monnet, F P; Koukoui, O; Prigent, S; Coquil, J F; Dupont, G; Combettes, L

    2011-07-01

    In hepatocytes, as in other cell types, Ca(2+) signaling is subject to complex regulations, which result largely from the intrinsic characteristics of the different inositol 1,4,5-trisphosphate receptor (InsP(3)R) isoforms and from their interactions with other proteins. Although sigma1 receptors (Sig-1Rs) are widely expressed in the liver, their involvement in hepatic Ca(2+) signaling remains unknown. We here report that in this cell type Sig-1R interact with type 1 isoforms of the InsP(3) receptors (InsP(3)R-1). These results obtained by immunoprecipitation experiments are confirmed by the observation that Sig-1R proteins and InsP(3)R-1 colocalize in hepatocytes. However, Sig-1R ligands have no effect on InsP(3)-induced Ca(2+) release in hepatocytes. This can be explained by the rather low expression level expression of InsP(3)R-1. In contrast, we find that Sig-1R ligands can inhibit agonist-induced Ca(2+) signaling via an inhibitory effect on InsP(3) synthesis. We show that this inhibition is due to the stimulation of PKC activity by Sig-1R, resulting in the well-known down-regulation of the signaling pathway responsible for the transduction of the extracellular stimulus into InsP(3) synthesis. The PKC sensitive to Sig-1R activity belongs to the family of conventional PKC, but the precise molecular mechanism of this regulation remains to be elucidated.

  17. Effects of natural and synthetic estrogens and various environmental contaminants on vitellogenesis in fish primary hepatocytes: comparison of bream (Abramis brama) and carp (Cyprinus carpio).

    Science.gov (United States)

    Rankouhi, T Rouhani; Sanderson, J T; van Holsteijn, I; van Leeuwen, C; Vethaak, A D; van den Berg, M

    2004-09-01

    Interaction of environmental estrogens with the estrogen receptor (ER) has been shown in various fish species. Our objective was to compare the sensitivity of bream (Abramis brama) to (xeno-)estrogens with that of the carp (Cyprinus carpio), by measuring the effects of 17beta-estradiol (E2), estrone (E1), ethynylestradiol (EE2), bisphenol A (BPA), nonylphenol (NP), methoxychlor (MXCL), and halogenated aromatic hydrocarbons (HAHs) such as polychlorinated biphenyls (PCB126, PCB118), 2,3,7,8-tetrachlorodibenzo-dioxin (TCDD), and 2,3,4,7,8-pentachlorodibenzofuran (PCDF) on vitellogenesis in primary hepatocytes. Comparing the EC50 values in bream hepatocytes: EE2 (0.1-0.2 microM) estrogenic potency of E2 and E1, indicating interspecies differences. Exposure to BPA, NP, MXCL, and HAHs did not or only weakly induce vitellogenesis. Bream hepatocytes coexposed to E2 and TCDD, PCB126 or PCDF showed a concentration-dependent inhibition of E2-induced vitellogenesis. IC50 (concentration of a compound that elicits 50% inhibition of E2-induced vitellogenesis) values determined in bream were: TCDD (0.02-0.09 nM) estrogenic response. IC50 values and benchmark-concentration for TCDD and PCB126 in bream and carp hepatocytes were in the same range, indicating similar sensitivity to these compounds. Due to their anti-estrogenic capacity with benchmark-concentrations in the pM range TCDD, PCDF, and PCB126 may form a potential hazard for the reproductive success of fish species by inhibition of vitellogenesis.

  18. Molecular mechanisms underlying the cholesterol-lowering effect of Ginkgo biloba extract in hepatocytes: a comparative study with Iovastatin

    Institute of Scientific and Technical Information of China (English)

    Zuo-quan XIE; Gai LIANG; Lu ZHANG; Qi WANG; Yi QU; Yang GAO; Li-bo LIN; Sai YE; Ji ZHANG; Hui WANG; Guo-ping ZHAO; Qing-hua ZHANG

    2009-01-01

    Aim: To explore the molecular mechanisms underlying the cholesterol-lowering effect of a Ginkgo biloba extract (GBE). Methods: Enzyme activity, cholesterol flux and changes in gene expression levels were assessed in cultured hepatocytes treated with GBE or Iovastatin. Results: GBE decreased the total cholesterol content in cultured hepatocytes and inhibited the activity of HMG-CoA reductase, as determined by an in vitro enzyme activity assay. In addition, GBE decreased cholesterol influx, whereas Iovastatin increased choles-terol influx. GBE treatment induced significant increases in the expression of cholesterogenic genes and genes involved in cholesterol metabolism, such as SREBF2, as determined by cDNA microarray and real-time RT-PCR. Furthermore, INSIG2, LDLR, LRP1, and LRP10 were differentially regulated by GBE and Iovastatin. The data imply that the two compounds modulate cholesterol metabolism through distinct mechanisms. Conclusion: By using a gene expression profiling approach, we were able to broaden the understanding of the molecular mechanisms by which GBE lowers cellular cholesterol levels. Specifically, we demonstrated that GBE exhibited dual effects on the cellular choles-terol pool by modulating both HMG-CoA reductase activity and inhibiting cholesterol influx.

  19. A role for lipid rafts in the protection afforded by docosahexaenoic acid against ethanol toxicity in primary rat hepatocytes.

    Science.gov (United States)

    Aliche-Djoudi, Fatiha; Podechard, Normand; Collin, Aurore; Chevanne, Martine; Provost, Emilie; Poul, Martine; Le Hégarat, Ludovic; Catheline, Daniel; Legrand, Philippe; Dimanche-Boitrel, Marie-Thérèse; Lagadic-Gossmann, Dominique; Sergent, Odile

    2013-10-01

    Previously, we demonstrated that eicosapentaenoic acid enhanced ethanol-induced oxidative stress and cell death in primary rat hepatocytes via an increase in membrane fluidity and lipid raft clustering. In this context, another n-3 polyunsaturated fatty acid, docosahexaenoic acid (DHA), was tested with a special emphasis on physical and chemical alteration of lipid rafts. Pretreatment of hepatocytes with DHA reduced significantly ethanol-induced oxidative stress and cell death. DHA protection could be related to an alteration of lipid rafts. Indeed, rafts exhibited a marked increase in membrane fluidity and packing defects leading to the exclusion of a raft protein marker, flotillin. Furthermore, DHA strongly inhibited disulfide bridge formation, even in control cells, thus suggesting a disruption of protein-protein interactions inside lipid rafts. This particular spatial organization of lipid rafts due to DHA subsequently prevented the ethanol-induced lipid raft clustering. Such a prevention was then responsible for the inhibition of phospholipase C-γ translocation into rafts, and consequently of both lysosome accumulation and elevation in cellular low-molecular-weight iron content, a prooxidant factor. In total, the present study suggests that DHA supplementation could represent a new preventive approach for patients with alcoholic liver disease based upon modulation of the membrane structures.

  20. [Cytoskeletal reorganization in hepatocytes of the regenerating mouse liver].

    Science.gov (United States)

    Gleĭberman, A S; Troianovskiĭ, S M; Bannikov, G A

    1984-12-01

    The intracellular pattern of prekeratin and actin filaments has been studied on sections of mouse livers regenerating after CCl4 injury. Monoclonal antibodies against one of liver prekeratins and monospecific polyclonal actin antibodies were used in the indirect immunofluorescent test. The presence of alpha-fetoprotein and bile canaliculi antigen was also monitored during regeneration. In control livers, prekeratin and actin filaments formed thick bundles adjacent to plasma membranes. The cytoplasmic prekeratin network was unmarked. In contrast to the latter, the bright well developed intracytoplasmic prekeratin network and intracytoplasmic actin fibers were identified in the perinecrotic hepatocytes by the 3d-4th day of regeneration. This rearrangement of the cytoskeleton coincided in time with the appearance of alpha-fetoprotein and the loss of the bile canaliculi antigen in the perinecrotic hepatocytes.

  1. Effects of electroporation on primary rat hepatocytes in vitro

    Institute of Scientific and Technical Information of China (English)

    Yun-Qing Yao; Ding-Feng Zhang; Ai-Long Huang; Yun Luo; Da-Zhi Zhang; Bo Wang; Wei-Ping Zhou; Hong Ren; Shu-Hua Guo

    2002-01-01

    AIM: To investigate the effects of electroporation on primaryrat hepatocyte and to optimize the electroporation conditionsintroducing foreign genes into primary hepatocytes.METHODS: A single-pulse procedure was performed at Iowvoltage (220-400 V) but with high capacitance (500-950 μF).Hepatocytes were divided into 4 groups according to theelectroporation conditions: group Ⅰ, 220 V and 500 μF;group Ⅱ, 220 Vand 950 μF; group Ⅲ, 400 V and 950 μF,and group Ⅳ.The control group was freshly isolatedhepatocytes and directly cultured under the same conditionsas those of electroporation groups. The effects ofelectroporation on primary rat hepatocytes were detectedby trypan blue exclusion (TBE) and MTT analysis. Besides,albumin (AIb), alanine transaminase (ALT) and lactatedehydrogenase (LDH) in the supernatants of culturedhepatocytes were measured by biochemical assay.RESULTS: Between day 1 and day 15 after incubation,primary rat hepatocytes of each electroporation groupappeared normal, being the same with those of controlgroup. TBE staining showed that slight hepatocyte damageand high survival rate were found in the electroporationgroups and the control group. Cultured for 3, 7, 11 and 15days, hepatocyte viability was approximatly 92.6±2.5 %,89.5±3.3 %, 82.0±3.5 % and 74.3±1.2 %, respectively.MTT analysis indicated that the viabilities of hepatocyteshad no significant difference between each electroporationgroup, and those were similar to that of control group. Atthe 36th hour after electroporation, AIb, ALT and LDH in thesupernatants of control group were 5.3±0.1 g. L-1, 183.7±8.4 nkat. L-1 and 896.8±58.5 nkat. L-1; those of group Ⅱwere 5.7±0.1 g. L-1, 215.4±16.7 nkat. L-1 and 1063.8±51.8 nkat. L-1; and those of group Ⅲ were 5.80.2 g. L-1,217.1 ± 8.4 nkat. L-1 and 1063.8± 10.0 nkat. L-1 . Statistically,the proteins of group Ⅱ and group Ⅲ were significantlyhigher than those of control group (P<0.05), whereas theprotein production of group

  2. The cytoskeleton of digitonin-treated rat hepatocytes.

    Science.gov (United States)

    Fiskum, G; Craig, S W; Decker, G L; Lehninger, A L

    1980-06-01

    Treatment of isolated rat hepatocptes with low concentrations of digitonin increases the permeability of the plsma membrane to cytosolic proteins without causing release of organelles such as mitochondria into the surrounding medium. Electron microscopy showed that treatment of the cells with increasing concentations of digitonin results in a progressive loss in the continuity of the plasma membrane, while most other aspects of cellular morphology remain normal. Depletion of background staining material from the cytosol by digitonin treatment of the cells greatly enhances the visualization of the cytoskeleton. The use of this technique, together with immunofluorescent light microscopy, has verified the presence of an actin-containing filamentous network at the hepatocyte cortex as well as intermediate filaments distributed throughout the cell. Digitonin is thus useful both for selectively permeabilizing the plasma membrane and for intensifying the appearance of intracellular structures such as microfilaments that are normally difficult to observe in cells such as hepatocytes.

  3. Detection of Dichlorvos Adducts in a Hepatocyte Cell Line

    Science.gov (United States)

    2014-06-30

    G6019) was obtained from Sigma (St. Louis, MS), human actin gamma recombinant protein (ACTG1, H00000071) and lactate dehydrogenase A recombi - nant...microRNA and mRNA expression profiling analysis of dichlorvos cytotoxicity in porcine kidney epithelial PK15 cells. DNA Cell Biol. 2011, 30 (12), 1073...Dissociation of DDVP-induced DNA strand breaks from oxidative damage in isolated rat hepatocytes. Toxicology 1996, 108 (1−2), 49−56. (40) Clapp, C.; Portt, L

  4. Prediction of fraction metabolized via CYP3A in humans utilizing cryopreserved human hepatocytes from a set of 12 single donors.

    Science.gov (United States)

    Desbans, C; Hilgendorf, C; Lutz, M; Bachellier, P; Zacharias, T; Weber, J C; Dolgos, H; Richert, L; Ungell, A-L

    2014-01-01

    1.  It has previously been demonstrated that metabolism of drugs via a single enzymatic pathway, particularly CYP3A4, is associated with increased risk for drug-drug interactions (DDI). Quantitative experimental systems as well as integrated prediction models to assess such risk during the preclinical phase are highly warranted. 2.  The present study was designed to systematically investigate the performance of human cryopreserved hepatocytes in suspension to predict fraction metabolized via CYP3A (fmCYP3A) by assessing the ketoconazole sensitive intrinsic clearance (CLint) for five prototypical CYP3A substrates with varying degree of CYP3A dependent CLint in twelve individual hepatocyte batches. 3.  We demonstrate that in contrast to well predicted mean hepatic metabolic clearance (CLH) and mean fmCYP3A data, the variability in CYP3A contribution for compounds having multiple metabolic pathways cannot be predicted from inhibition experiments using ketoconazole as inhibitor. Instead, data in the present paper indicate that the variability is larger after inhibition of CYP3A for compounds having multiple metabolic pathways. 4.  It is therefore recommended to estimate the average CLint and fmCYP3A for a given test compound in a series (n = 10) of individual human hepatocyte batches.

  5. SREBP-1c Gene Silencing can Decrease Lipid Deposits in Bovine Hepatocytes Cultured in Vitro

    Directory of Open Access Journals (Sweden)

    Qinghua Deng

    2014-05-01

    Full Text Available Background: Fatty liver is a major metabolic disorder that occurs during early lactation in high-producing dairy cows. Sterol regulatory element-binding protein-1c (SREBP-1c is an important transcription factor that regulates lipid synthesis by regulating the expression of lipid metabolism genes. Methods: In this study, we reduced the expression of SREBP-1c by adenovirus-mediated SREBP-1c with a low expression vector (AD-GFP-SREBP-1c to study the effects of SREBP-1c on lipid deposits in bovine hepatocytes. The expression levels and enzyme activities of SERBP-1c and its target genes were determined by real-time PCR, western blot, and ELISA. Results: These results showed that Ad-GFP-SREBP-1c could inhibit SREBP-1c expression. The expression of the lipid synthesis enzyme acetyl-CoA carboxylase (ACC was down-regulated. The expression levels of the lipid oxidation enzymes long-chain fatty acyl-COA synthetase (ACSL-1, carnitine palmitoyltransferase І (CPT-І, carnitine palmitoyltransferase II (CPT- II, and β-hydroxyacyl-CoA-DH (HADH were significantly elevated. Furthermore, the expression levels of factors involved in the assembly and transport of very low-density lipoproteins (VLDLs, such as apolipoprotein B100 (ApoB, apolipoprotein E (ApoE, and microsomal triglyceride transfer protein (MTTP were decreased comparison with the negative control and the blank control groups, but the low-density lipoprotein receptor (LDLR was elevated. The concentrations of TG (triglyceride and VLDL were also reduced. Conclusion: These data suggest that low SREBP-1c expression can decrease lipid synthesis, increase lipid oxidation, and decrease the TG and VLDL content in bovine hepatocytes.

  6. Evidence for a channel for the electrogenic transport of chloride ion in the rat hepatocyte

    Energy Technology Data Exchange (ETDEWEB)

    Bear, C.E.; Petrunka, C.N.; Strasberg, S.M.

    1985-05-01

    Chloride is the major inorganic anion in bile but its mechanism of passage from blood to bile is uncertain. Specific membrane channels account for most net inorganic anion flux in other cell types such as the proximal tubular cell and red blood cell; disulfonic stilbenes inhibit anion movement through these channels. Therefore, we have sought the presence of similar channels in the hepatocyte. Net inorganic anion flux or conductance was initiated in isolated rat hepatocytes by valinomycin in the presence of an outward potassium gradient. Potassium concentration in the extracellular medium increased from 2.75 +/- 0.02 in control cell suspensions to 3.15 +/- 0.04 in valinomycin-treated cell suspensions. Membrane potential difference (Em) (mV), determined as the distribution of (/sup 14/C)tetraphenyl phosphonium ion was -28 mV in control cells and -42 mV in valinomycin-treated cells. Intracellular chloride concentration (/sup 36/Cl-) (mEq per liter of cell water) decreased significantly from 38.6 in control cells to 32.0 in valinomycin-treated cells. The observed intracellular concentrations (/sup 36/Cl-) in both control and valinomycin-treated cell suspensions closely approximates values predicted on the basis of the Nernst equation: 41 and 29 (mEq per liter of cell water), respectively, suggesting that the chloride ion is passively distributed on the basis of the membrane potential difference. Furthermore, net rate-limited cell water loss of approximately 15% of control values was associated with the above valinomycin-stimulated changes in ion distribution, as assessed using three methods of cell water volume determination.

  7. Targeted in vivo delivery of siRNA and an endosome-releasing agent to hepatocytes.

    Science.gov (United States)

    Sebestyén, Magdolna G; Wong, So C; Trubetskoy, Vladimir; Lewis, David L; Wooddell, Christine I

    2015-01-01

    The discoveries of RNA interference (RNAi) and short interfering RNAs (siRNAs) have provided the opportunity to treat diseases in a fundamentally new way: by co-opting a natural process to inhibit gene expression at the mRNA level. Given that siRNAs must interact with the cells' natural RNAi machinery in order to exert their silencing effect, one of the most fundamental requirements for their use is efficient delivery to the desired cell type and, specifically, into the cytoplasm of those cells. Numerous research efforts involving the testing of a large number of delivery approaches using various carrier molecules and inventing several distinct formulation technologies during the past decade illustrate the difficulty and complexity of this task. We have developed synthetic polymer formulations for in vivo siRNA delivery named Dynamic PolyConjugates™ (DPCs) that are designed to mimic the features viruses possess for efficient delivery of their nucleic acids. These include small size, long half-life in circulation, capability of displaying distinct host cell tropism, efficient receptor binding and cell entry, disassembly in the endosome and subsequent release of the nucleic acid cargo to the cytoplasm. Here we present an example of this delivery platform composed of a hepatocyte-targeted endosome-releasing agent and a cholesterol-conjugated siRNA (chol-siRNA). This delivery platform forms the basis of ARC-520, an siRNA-based therapeutic for the treatment of chronic hepatitis B virus (HBV) infection. In this chapter, we provide a general overview of the steps in developing ARC-520 and detailed protocols for two critical stages of the discovery process: (1) verifying targeted in vivo delivery to hepatocytes and (2) evaluating in vivo drug efficacy using a mouse model of chronic HBV infection.

  8. The responses of rat hepatocytes to glucagon and adrenaline. Application of quantified elasticity analysis.

    Science.gov (United States)

    Ainscow, E K; Brand, M D

    1999-11-01

    The internal control of hepatocyte metabolism has been previously analysed using metabolic control analysis. The aim of this paper is to extend this analysis to include the responses of the cells to hormonal stimulus. Hepatocyte metabolism was divided into nine reaction blocks: glycogen breakdown, glucose release, glycolysis, lactate production, NADH oxidation, pyruvate oxidation, proton leak, mitochondrial phosphorylation and ATP consumption, linked by five intermediates: mitochondrial membrane potential, cytoplasmic NADH/NAD and total cellular ATP, glucose 6-phosphate and pyruvate. The kinetic responses of the reaction blocks to the intermediates were determined previously in the absence of added hormones. In this study, the changes in flux and intermediate levels that occurred upon addition of either glucagon or adrenaline were measured. From comparison of the fractional changes in fluxes and intermediate levels with the known kinetics of the system, it was possible to determine the primary sites of action of the hormones. The results show that the majority of processes in the cell are responsive to the hormones. The notable exception to this is the failure of adrenaline to have a direct effect on glycolysis. The activity change of each metabolic block observed in the presence of either hormone was quantified and compared to the indirect effects on each block caused by changes in metabolite levels. The second stage of the analysis was to use the calculated activity changes and the known control pattern of the system to give a semiquantitative analysis of the regulatory pathways employed by the hormones to achieve the changes in fluxes and metabolite levels. This was instructive in analysing, for example, how glucagon caused a decrease in flux through glycolysis and an increase in oxidative phosphorylation without large changes in metabolite levels (homeostasis). Conversely, it could be seen that the failure of adrenaline to maintain a constant glucose 6

  9. Biomaterial Scaffolds with Biomimetic Fluidic Channels for Hepatocyte Culture

    Institute of Scientific and Technical Information of China (English)

    Xiao Li; Jiankang He; Yaxiong Liu; Qian Zhao; Wanquan Wu; Dichen Li; Zhongmin Jin

    2013-01-01

    Biomaterial scaffolds play an important role in maintaining the viability and biological functions of highly metabolic hepatocytes in liver tissue engineering.One of the major challenges involves building a complex microchannel network inside three-dimensional (3D) scaffolds for efficient mass transportation.Here we presented a biomimetic strategy to generate a microchannel network within porous biomaterial scaffolds by mimicking the vascular tree of rat liver.The typical parameters of the blood vessels were incorporated into the biomimetic design of the microchannel network such as branching angle and diameter.Silk fibroin-gelatin scaffolds with biomimetic vascular tree were fabricated by combining micromolding,freeze drying and 3D rolling techniques.The relationship between the micro-channeled design and flow pattern was revealed by a flow experiment,which indicated that the scaffolds with biomimetic vascular tree exhibited unique capability in improving mass transportation inside the 3D scaffold.The 3D scaffolds,preseeded with primary hepatocytes,were dynamically cultured in a bioreactor system.The results confirmed that the pre-designed biomimetic microchannel network facilitated the generation and expansion of hepatocytes.

  10. Hepatocyte and Sertoli Cell Aquaporins, Recent Advances and Research Trends

    Science.gov (United States)

    Bernardino, Raquel L.; Marinelli, Raul A.; Maggio, Anna; Gena, Patrizia; Cataldo, Ilaria; Alves, Marco G.; Svelto, Maria; Oliveira, Pedro F.; Calamita, Giuseppe

    2016-01-01

    Aquaporins (AQPs) are proteinaceous channels widespread in nature where they allow facilitated permeation of water and uncharged through cellular membranes. AQPs play a number of important roles in both health and disease. This review focuses on the most recent advances and research trends regarding the expression and modulation, as well as physiological and pathophysiological functions of AQPs in hepatocytes and Sertoli cells (SCs). Besides their involvement in bile formation, hepatocyte AQPs are involved in maintaining energy balance acting in hepatic gluconeogenesis and lipid metabolism, and in critical processes such as ammonia detoxification and mitochondrial output of hydrogen peroxide. Roles are played in clinical disorders including fatty liver disease, diabetes, obesity, cholestasis, hepatic cirrhosis and hepatocarcinoma. In the seminiferous tubules, particularly in SCs, AQPs are also widely expressed and seem to be implicated in the various stages of spermatogenesis. Like in hepatocytes, AQPs may be involved in maintaining energy homeostasis in these cells and have a major role in the metabolic cooperation established in the testicular tissue. Altogether, this information represents the mainstay of current and future investigation in an expanding field. PMID:27409609

  11. Silver nanoparticles stimulate glycogenolysis in rainbow trout (Oncorhynchus mykiss) hepatocytes.

    Science.gov (United States)

    Massarsky, Andrey; Labarre, Justine; Trudeau, Vance L; Moon, Thomas W

    2014-02-01

    Silver nanoparticles (AgNPs) are found in many consumer products yet their biological effects on non-target aquatic organisms are yet to be fully understood. This research aimed to investigate the effects of AgNPs on cell signaling in rainbow trout (Oncorhynchus mykiss) hepatocytes. We focused on the β-adrenoreceptor (AR), which mediates glycogenolysis, and the glucocorticoid receptor (GCR), which mediates gluconeogenesis. These two receptors have been extensively studied in trout hepatocytes due to their key roles during the stress response to increase glucose availability (among other things), allowing the organisms to cope with the stressor. We show for the first time that AgNPs at a concentration of 1 μg/mL did not interfere with the function of either the β-AR or the GCR systems in rainbow trout hepatocytes, but at the concentration of 10 μg/mL AgNPs stimulated glycogenolysis which was apparently receptor-independent. This study suggests that AgNPs could affect hormone-regulated cell signaling pathways at a concentration of 10 μg/mL.

  12. A fast and robust hepatocyte quantification algorithm including vein processing

    Directory of Open Access Journals (Sweden)

    Homeyer André

    2010-03-01

    Full Text Available Abstract Background Quantification of different types of cells is often needed for analysis of histological images. In our project, we compute the relative number of proliferating hepatocytes for the evaluation of the regeneration process after partial hepatectomy in normal rat livers. Results Our presented automatic approach for hepatocyte (HC quantification is suitable for the analysis of an entire digitized histological section given in form of a series of images. It is the main part of an automatic hepatocyte quantification tool that allows for the computation of the ratio between the number of proliferating HC-nuclei and the total number of all HC-nuclei for a series of images in one processing run. The processing pipeline allows us to obtain desired and valuable results for a wide range of images with different properties without additional parameter adjustment. Comparing the obtained segmentation results with a manually retrieved segmentation mask which is considered to be the ground truth, we achieve results with sensitivity above 90% and false positive fraction below 15%. Conclusions The proposed automatic procedure gives results with high sensitivity and low false positive fraction and can be applied to process entire stained sections.

  13. Gene expression changes after hypoxic preconditioning in rat hepatocytes

    Institute of Scientific and Technical Information of China (English)

    Wei Chen; Jiang-Feng Qiu; Zhi-Qi Zhang; Hai-Feng Luo; Joan Rosello-Catafau; Zhi-Yong Wu

    2006-01-01

    BACKGROUND: Hypoxic preconditioning can protect hepatocytes against hypoxic injury, but its mechanism has not been elucidated. The aim of this study was to proifle gene expression patterns involved in hypoxic preconditioning and probable mechanism at the level of gene expression. METHODS: Hepatocytes were divided into 2 groups:control group and hypoxic preconditioning group. Biotin-labeled cRNA from the control group and the hypoxic preconditioning group was hybridized by oligonucleotide microarray. Genes that were signiifcantly associated with hypoxic preconditioning were ifltered, and validated at the level of transcript expression. RESULTS: Forty-three genes with signiifcantly altered expression patterns were discovered and most of them had not been previously reported. Among these genes, genes encoding superoxide dismutase 2 (SOD2)and interleukin 10 (IL-10) in the hypoxic preconditioning group were conifrmed to be up-regulated with real-time quantitative PCR. CONCLUSIONS:Many cytokines are involved in hypoxic preconditioning and protect hepatocytes from hypoxia-reoxygenation injury, and the increase of oxygen free-radical scavengers and anti-inlfammatory factors may play a key role in this phenomenon. Diverse signal pathways are probably involved.

  14. Effects of 2,3,7,8-TCDD and benzo[a]pyrene on modulating vitellogenin expression in primary culture of crucian carp (Carassius auratus) hepatocytes

    Institute of Scientific and Technical Information of China (English)

    LIANG Yong; C. K. C. Wong; XU Ying; M. H. Wong

    2004-01-01

    Vitellogenin (Vtg) is the precursor of yolk protein. Its expression and secretion are estrogen-regulated and are crucial for oocyte maturation. An in vitro xenoestrogen screening model was established by measuring Vtg induction in cultured primary hepatocytes from crucian carp. Vtg production was detected by biotin-avidin sandwich ELISA method while Vtg and cytochrome P4501A1 (CYP1A1) mRNA induction were measured by semi- quantitative PCR-primer dropping technique. Vtg and Vtg mRNA were dose-dependently induced by diethylstilbestrol (DES, 0.2-200 ng/mL) in hepatocytes of crucian carp. Co-treatment of the DES-induced hepatocytes with either 2,3,7,8-TCDD (TCDD, 0.1-4 pg/mL) or benzo[a]pyrene (B[a]P, 5-1000 ng/mL) resulted in a reduction of Vtg production and an increment of CYP1A1 mRNA expression both in a dose dependent manner, indicating the anti-estro-genic effects of the compounds. However, at lower tested concentrations, TCDD (0.1, 0.2 pg/mL), B[a]P (5 ng/mL) seemed to have a potentiating effect on Vtg expression and secretion, although by their own these compounds had no observable estrogenic effect on Vtg induction. Tamoxifen (a selective estrogen receptor modulators, 1 nmol/L-1 μmol/L), and β-naphtho-flavone (β-NF, an aryl hydrocarbon receptor inducing compounds, 2.5-1000 ng/mL) also were employed to study the possible interactions in DES-induced Vtg expression. In co-treatment of the DES-induced hepatocytes with β-NF or tamoxifen, the decrease in Vtg production did parallel induction of CYP1A1 for β-NF, but tamoxifen inhibited Vtg induction did not parallel induced CYP1A1 expression in all test concentrations. On the contrary, it was found that in co-treatment of the TCDD-induced hepatocytes with DES, TCDD induced CYP1A1 mRNA production was inhibited by DES also. These results implicated a possible cross talk between estrogen receptor- and aryl hydrocarbon receptor-mediated pathways in the hepatocytes.

  15. Freshly isolated hepatocyte transplantation in acetaminophen-induced hepatotoxicity model in rats

    Directory of Open Access Journals (Sweden)

    Daniela Rodrigues

    2012-12-01

    Full Text Available CONTEXT: Hepatocyte transplantation is an attractive therapeutic modality for liver disease as an alternative for orthotopic liver transplantation. OBJECTIVE: The aim of the current study was to investigate the feasibility of freshly isolated rat hepatocyte transplantation in acetaminophen-induced hepatotoxicity model. METHODS: Hepatocytes were isolated from male Wistar rats and transplanted 24 hours after acetaminophen administration in female recipients. Female rats received either 1x10(7 hepatocytes or phosphate buffered saline through the portal vein or into the spleen and were sacrificed after 48 hours. RESULTS: Alanine aminotransferase levels measured within the experiment did not differ between groups at any time point. Molecular analysis and histology showed presence of hepatocytes in liver of transplanted animals injected either through portal vein or spleen. CONCLUSION: These data demonstrate the feasibility and efficacy of hepatocyte transplantation in the liver or spleen in a mild acetaminophen-induced hepatotoxicity model.

  16. Depot-dependent effects of adipose tissue explants on co-cultured hepatocytes

    DEFF Research Database (Denmark)

    Du, Zhen-Yu; Ma, Tao; Lock, Erik-Jan;

    2011-01-01

    a stronger cytotoxic response and higher level of insulin resistance in the co-cultured hepatocytes. In conclusion, our results reveal depot-dependent effects of ATEs on co-cultured primary hepatocytes, which in part may be related to a more pronounced infiltration of stromal vascular cells (SVCs......We have developed an in vitro hepatocyte-adipose tissue explant (ATE) co-culture model enabling examination of the effect of visceral and subcutaneous adipose tissues on primary rat hepatocytes. Initial analyses of inflammatory marker genes were performed in fractionated epididymal or inguinal...... levels of IL-6, TNF-a and PGE(2) in the media from inguinal ATEs co-cultured with primary rat hepatocytes were higher than that in the media from epididymal ATEs co-cultured with hepatocytes, although the significant difference was only seen in PGE(2). Lipolysis, measured as glycerol release, was similar...

  17. Statins alter the hepatobiliary transport of unconjugated and conjugated bilirubin in sandwich-cultured rat hepatocytes.

    Science.gov (United States)

    Szabó, Mónika; Veres, Zsuzsa; Bátai-Konczos, Attila; Kékesi, Orsolya; Kis, Emese; Szabó, Kitti; Jemnitz, Katalin

    2014-09-01

    Several studies have reported that statins occasionally cause impairment of liver functions characterized by elevated serum bilirubin levels, which might be due to altered function of the multidrug resistance-associated proteins (Mrp2/3). We aimed to study the modulation of the hepatobiliary transport of bilirubin by four statin derivatives, atorvastatin, fluvastatin, pravastatin, and rosuvastatin in sandwich-cultured rat hepatocytes. All statins except pravastatin significantly inhibited the uptake of bilirubin. The biliary efflux of bilirubin conjugates was increased by pravastatin and rosuvastatin concentration dependently. Rosuvastatin stimulated not only the Mrp2 mediated biliary, but the Mrp3 mediated sinusoidal elimination, resulting in decreased intracellular bilirubin accumulation. The significantly induced Mrp2/3 protein levels (ranging from 1.5 to 1.8-fold) accounted for the elevated efflux. Cell polarization, the formation of biliary network was also significantly increased by fluvastatin, pravastatin and rosuvastatin (151%, 216% and 275% of the control, respectively). The simultaneous inhibition of the uptake and the stimulation of the sinusoidal and canalicular elimination may explain, at least in part, the clinical observation of elevated serum bilirubin levels. In conclusion, our results suggest that in spite of the elevated serum bilirubin levels, the altered Mrp2 and Mrp3 functions by statins is probably not associated with hepatotoxic effects.

  18. Antioxidant effect of a fermented powder of Lady Joy bean in primary rat hepatocytes.

    Science.gov (United States)

    La Marca, Margherita; Pucci, Laura; Bollini, Roberto; Russo, Rossella; Sparvoli, Francesca; Gabriele, Morena; Longo, Vincenzo

    2015-03-01

    The role and beneficial effects of plant and food extracts against various diseases induced by oxidative stress have received much attention in recent years. Legumes are rich in bioactive compounds, and some studies suggest a correlation between their consumption and a reduced incidence of diseases. Primary cultures of rat hepatocytes were used to investigate whether and how an extract obtained from a fermented powder of bean named Lady Joy (Phaseolus vulgaris L.) is able to regulate antioxidant and detoxifying enzymes through the NRF2 pathway, inhibit NF-kB activation, and reduce H2O2-induced endoplasmic reticulum (ER) stress. All of the antioxidant and detoxifying enzymes studied were significantly up-regulated by Lady Joy treatment. Western blot showed that Nrf2 was activated by Lady Joy treatment. Also, cells treated with this fermented bean were partially protected against NF-kB activation resulting from H2O2 stress. As a link between oxidative stress and ER dysfunction is hypothesized, we verified whether Lady Joy was able to protect cells from H2O2-induced ER stress, by studying the response of the proteins CHOP, BiP and caspase 12. The results of this study show that Lady Joy can induce the Nrf2 pathway, inhibit NF-kB, and protect ER from stress induced by H2O2.

  19. TRANSPLANTATION OF HEPATOCYTES AS THE METHOD OF TREATMENT OF LIVER FAILURE: EXPERIMENTAL AND CLINICAL EXPERIENCE

    Directory of Open Access Journals (Sweden)

    M. Y. Shagidulin

    2010-01-01

    Full Text Available For correction and treatment of liver failure before liver transplantation were proposed severe methods such as: extracorporal devices, transplantation of hepatocytes and implanted tissue-engineering units. The function of healthy hepatocytes presumes to stabilize the state of patients with chronic liver diseases and to wait a donor organ transplantation. In this review the results of experimental and clinical therapy of liver diseases by method of hepatocyte transplantation were summarized. 

  20. Hepatocytes isolated from neoplastic liver-immunomagnetic purging as a new source for transplantation

    Institute of Scientific and Technical Information of China (English)

    Aravin Gunasegaram; Javed Akhter; Peng Yao; Loreena A Johnson; Stephen M Riodan; David L Morris

    2008-01-01

    AIM: To investigate whether hepatocytes isolated from macroscopically normal liver during hepatic resection for neoplasia could provide a novel source of healthy hepatocytes, including the development of reliable protocols for malignant cells removal from the hepatocyte preparation.METHODS: Hepatocytes were procured from resected liver of 18 patients with liver tumors using optimised digestion and cell-enrichment protocols. Suspensions of various known quantities of the HT-29 tumor cell line and patient hepatocytes were treated or not with Ep-CAM-antibody-coated immunomagnetic beads in order to investigate the efficacy of tumor-purging by immunomagnetic depletion, using a semi-quantitative RT-PCR method developed to detect tumor cells.Immunomagnetic bead-treated or bead-untreated tumor cell-hepatocyte suspensions were transplanted intra-peritoneally in Balb/C nude mice to assess the rates of tumor development.RESULTS: Mean viable hepatocyte yield was 9.3 x 106 cells per gram of digested liver with mean viability of 70.5%. Immunomagnetic depletion removed tumor cells to below the RT-PCR detection-threshold of 1 tumor cell in 106 hepatocytes, representing a maximum tumor purging efficacy of greater than 400000-fold.Transplanted, immunomagnetic bead-purged tumor cell-hepatocyte suspensions did not form peritoneal tumors in Balb/C nude mice. Co-transplantation of hepatocytes with tumor cells did not increase tumorigenesis of the tumor cells.CONCLUSION: Immunomagnetic depletion appears to be an effective method of purging contaminating tumor cells to below threshold for likely tumorigenesis.Along with improved techniques for isolation of large numbers of viable hepatocytes, normal liver resected for neoplasia has potential as another clinically useful source of hepatocytes for transplantation.

  1. FGF19-induced Hepatocyte Proliferation Is Mediated through FGFR4 Activation

    OpenAIRE

    Wu, Xinle; Ge, Hongfei; Lemon, Bryan; Vonderfecht, Steven; Weiszmann, Jennifer; Hecht, Randy; Gupte, Jamila; Hager, Todd; Wang, Zhulun; Lindberg, Richard; Li, Yang

    2009-01-01

    FGF19 and FGF21, unique members of the fibroblast growth factor (FGF) family, are hormones that regulate glucose, lipid, and energy homeostasis. Increased hepatocyte proliferation and liver tumor formation have also been observed in FGF19 transgenic mice. Here, we report that, in contrast to FGF19, FGF21 does not induce hepatocyte proliferation in vivo. To identify the mechanism for FGF19-induced hepatocyte proliferation, we explored similarities and differences in receptor specificity betwee...

  2. Heparanase enhances early hepatocyte inclusion in the recipient liver after transplantation in partially hepatectomized rats.

    Science.gov (United States)

    Tsiperson, Vladislav; Goldshmidt, Orit; Ilan, Neta; Shoshany, Gideon; Vlodavsky, Israel; Veitsman, Ella; Baruch, Yaacov

    2008-03-01

    Hepatocyte transplantation is an emerging approach for the treatment of liver diseases. However, broad clinical application of this method has been limited by restricted source of cells and low efficiency of cell integration within the recipient liver. Heparanase cleaves heparan sulfate proteoglycans in the extracellular matrix and basement membrane, activity that affects cellular invasion associated with cancer metastasis and inflammation. This activity has a multifunctional effect on cell-cell interaction, cell adhesion, and angiogenesis. All these factors are important for successful integration of transplanted hepatocytes. Male donor hepatocytes pretreated with heparanase or untreated were transplanted into recipient female rat spleen following partial hepatectomy. Engraftment efficacy was evaluated by PCR for Y chromosome, histology and PCNA, and heparanase immunohistochemistry. In addition, proliferative activity of hepatocytes in vitro was determined by bromodeoxyuridine immunostaining. The number of heparanase-treated cells detected in the recipient liver was significantly increased three- to fivefold within 24-48 h posttransplantation and twofold at 14 days compared with untreated cells. The transplanted hepatocytes treated with heparanase were clearly seen inside portal vein radicles as cell aggregates up to 72 h posttransplantation. The number of portal radicles filled with heparanase-treated hepatocytes was increased compared to control early after transplantation. Heparanase treatment enhanced hepatocyte and sinusoidal endothelial cell proliferation in the liver, and hepatocyte proliferation within the spleen tissue. Preliminary in vitro studies with isolated hepatocytes treated with heparanase showed increased proliferative activity within 24-48 h of cell culture. These results suggest that preincubation of hepatocytes with heparanase increases the presence of hepatocytes within the recipient liver early following cell transplantation and stimulates

  3. Freshly isolated hepatocyte transplantation in acetaminophen-induced hepatotoxicity model in rats

    OpenAIRE

    Daniela Rodrigues; Themis Reverbel Da Silveira; Ursula Matte

    2012-01-01

    CONTEXT: Hepatocyte transplantation is an attractive therapeutic modality for liver disease as an alternative for orthotopic liver transplantation. OBJECTIVE: The aim of the current study was to investigate the feasibility of freshly isolated rat hepatocyte transplantation in acetaminophen-induced hepatotoxicity model. METHODS: Hepatocytes were isolated from male Wistar rats and transplanted 24 hours after acetaminophen administration in female recipients. Female rats received either 1x10(7) ...

  4. The role of insulin, glucagon, dexamethasone, and leptin in the regulation of ketogenesis and glycogen storage in primary cultures of porcine hepatocytes prepared from 60 kg pigs.

    Science.gov (United States)

    Fernández-Fígares, I; Shannon, A E; Wray-Cahen, D; Caperna, T J

    2004-08-01

    A study was conducted to elucidate hormonal control of ketogenesis and glycogen deposition in primary cultures of porcine hepatocytes. Hepatocytes were isolated from pigs (54-68 kg) by collagenase perfusion and seeded into collagen-coated T-25 flasks. Monolayers were established in medium containing fetal bovine serum for 1 day and switched to a serum-free medium for the remainder of the culture period. Hepatocytes were maintained in DMEM/M199 containing 1% DMSO, dexamethasone (10(-6) or 10(-7) M), linoleic acid (3.4 x 10(-5) M), and carnitine (10(-3) M) for 3 days. On the first day of serum-free culture, insulin was added at 1 or 100 ng/ml and glucagon was added at 0, 1, or 100 ng/ml. Recombinant human leptin (200 ng/ml) was added during the final 24 h; medium and all cells were harvested on the third day. Concentrations of acetoacetate and beta-hydroxybutyrate (ketone bodies) in media and glycogen deposition in the cellular compartment were determined. Ketogenesis was highly stimulated by glucagon (1 and 100 ng/ml) and inhibited by insulin. In contrast, glycogen deposition was stimulated by insulin and attenuated by glucagon; high insulin was also associated with a reduction in the ketone body ratio (acetoacetate:beta-hydroxybutyrate). High levels of dexamethasone stimulated ketogenesis, but inhibited glycogen deposition at low insulin. Culture of cells with leptin for 24 h, over the range of insulin, glucagon, and dexamethasone concentrations had no effect on either glycogen deposition or ketogenesis. These data suggest that while adult porcine hepatocytes are indeed sensitive to hormonal manipulation, leptin has no direct influence on hepatic energy metabolism in swine.

  5. Transcriptional Up-Regulation of APE1/Ref-1 in Hepatic Tumor: Role in Hepatocytes Resistance to Oxidative Stress and Apoptosis.

    Directory of Open Access Journals (Sweden)

    Vittorio Di Maso

    Full Text Available Human Hepatocellular Carcinoma (HCC is the fifth most frequent neoplasm worldwide and the most serious complication of long-standing chronic liver diseases (CLD. Its development is associated with chronic inflammation and sustained oxidative stress. Deregulation of apurinic apyrimidinic endonuclease 1/redox effector factor 1 (APE1/Ref-1, a master regulator of cellular response to oxidative stress, has been associated with poor prognosis in several cancers including HCC.In the present study we investigated the APE1/Ref-1 mRNA levels in cirrhotic and HCC tissues obtained during HCC resection. The possible protective role of APE1/Ref-1 against oxidative stress and apoptosis was evaluated in vitro in immortalized human hepatocytes (IHH over-expressing APE1/Ref-1.APE1/Ref-1 was up-regulated in HCC, regulation occurring at the transcriptional level. APE1/Ref-1 mRNA content increased with the progression of liver disease with the transcriptional up-regulation present in cirrhosis significantly increased in HCC. The up-regulation was higher in the less differentiated cancers. In vitro, over-expression of APE1/Ref-1 in normal hepatocytes conferred cell protection against oxidative stress and it was associated with BAX inhibition and escape from apoptosis.APE1/Ref-1 is up-regulated in HCC and this over-expression correlates with cancer aggressiveness. The up-regulation occurs at the transcriptional level and it is present in the earliest phases of hepatocarcinogenesis. The APE-1/Ref-1 over-expression is associated with hepatocyte survival and inhibits BAX activation and apoptosis. These data suggest a possible role of APE1/Ref-1 over-expression both in hepatocyte survival and HCC development calling attention to this molecule as a promising marker for HCC diagnosis and treatment.

  6. Three-dimensional (3D) printing of mouse primary hepatocytes to generate 3D hepatic structure

    Science.gov (United States)

    Kim, Yohan; Kang, Kyojin; Jeong, Jaemin; Paik, Seung Sam; Kim, Ji Sook; Park, Su A; Kim, Wan Doo; Park, Jisun

    2017-01-01

    Purpose The major problem in producing artificial livers is that primary hepatocytes cannot be cultured for many days. Recently, 3-dimensional (3D) printing technology draws attention and this technology regarded as a useful tool for current cell biology. By using the 3D bio-printing, these problems can be resolved. Methods To generate 3D bio-printed structures (25 mm × 25 mm), cells-alginate constructs were fabricated by 3D bio-printing system. Mouse primary hepatocytes were isolated from the livers of 6–8 weeks old mice by a 2-step collagenase method. Samples of 4 × 107 hepatocytes with 80%–90% viability were printed with 3% alginate solution, and cultured with well-defined culture medium for primary hepatocytes. To confirm functional ability of hepatocytes cultured on 3D alginate scaffold, we conducted quantitative real-time polymerase chain reaction and immunofluorescence with hepatic marker genes. Results Isolated primary hepatocytes were printed with alginate. The 3D printed hepatocytes remained alive for 14 days. Gene expression levels of Albumin, HNF-4α and Foxa3 were gradually increased in the 3D structures. Immunofluorescence analysis showed that the primary hepatocytes produced hepatic-specific proteins over the same period of time. Conclusion Our research indicates that 3D bio-printing technique can be used for long-term culture of primary hepatocytes. It can therefore be used for drug screening and as a potential method of producing artificial livers. PMID:28203553

  7. Hepatitis B virus infection and replication in primarily cultured human fetal hepatocytes

    Institute of Scientific and Technical Information of China (English)

    Min Lin; Qun Chen; Li-Ye Yang; Wen-Yu Li; Xi-Biao Cao; Jiao-Ren Wu; You-Peng Peng; Mo-Rui Chen

    2007-01-01

    AIM:To investigate the infection and replication of hepatitis B virus(HBV)in primarily cultured human fetal hepatocytes(HFHs).METHODS:The human fetal hepatocytes were cultured in serum-free medium,HBV-positive serum was added into the medium to study the susceptibility of hepatocytes to HBV infection.The supernatant was collected for ELISA assay of HBsAg and HBeAg,and quantitative fluorescence PCR for HBV-DNA assay daily.Albumin and HBcAg,CK8 and CK18 expressions were detected by immunohistochemistry in cultured hepatocytes.Content of lactate dehydrogenate(LDH)was measured to find out the integrity of the cell membrane.RESULTS:A stable hepatocyte culture system was established.HBV could infect the hepatocytes and replicate,and HBcAg expression could be detected by immunohistochemistry in hepatocyte-like cells.HBV-DNA in the supernatant could be detected from d 2 to d 18 and HBsAg and HBeAg were positive on d 3-d 18 after HBV infection.HBV in medium increased from d 0 to d 6 and subsequently decreased as the cells were progressively loosing their hepatocyte phenotypes.CONCLUSION:HBV could infect human fetal hepatocytes and replicate.This in vitro model allowed a detailed Study on early events associated with human HBV entry into cells and subsequent replication.

  8. Cholesterol Enhances the Toxic Effect of Ethanol and Acetaldehyde in Primary Mouse Hepatocytes.

    Science.gov (United States)

    López-Islas, Anayelly; Chagoya-Hazas, Victoria; Pérez-Aguilar, Benjamin; Palestino-Domínguez, Mayrel; Souza, Verónica; Miranda, Roxana U; Bucio, Leticia; Gómez-Quiroz, Luis Enrique; Gutiérrez-Ruiz, María-Concepción

    2016-01-01

    Obesity and alcohol consumption are risk factors for hepatic steatosis, and both commonly coexist. Our objective was to evaluate the effect of ethanol and acetaldehyde on primary hepatocytes obtained from mice fed for two days with a high cholesterol (HC) diet. HC hepatocytes increased lipid and cholesterol content. HC diet sensitized hepatocytes to the toxic effect of ethanol and acetaldehyde. Cyp2E1 content increased with HC diet, as well as in those treated with ethanol or acetaldehyde, while the activity of this enzyme determined in microsomes increased in the HC and in all ethanol treated hepatocytes, HC and CW. Oxidized proteins were increased in the HC cultures treated or not with the toxins. Transmission electron microscopy showed endoplasmic reticulum (ER) stress and megamitochondria in hepatocytes treated with ethanol as in HC and the ethanol HC treated hepatocytes. ER stress determined by PERK content was increased in ethanol treated hepatocytes from HC mice and CW. Nuclear translocation of ATF6 was observed in HC hepatocytes treated with ethanol, results that indicate that lipids overload and ethanol treatment favor ER stress. Oxidative stress, ER stress, and mitochondrial damage underlie potential mechanisms for increased damage in steatotic hepatocyte treated with ethanol.

  9. Cholesterol Enhances the Toxic Effect of Ethanol and Acetaldehyde in Primary Mouse Hepatocytes

    Directory of Open Access Journals (Sweden)

    Anayelly López-Islas

    2016-01-01

    Full Text Available Obesity and alcohol consumption are risk factors for hepatic steatosis, and both commonly coexist. Our objective was to evaluate the effect of ethanol and acetaldehyde on primary hepatocytes obtained from mice fed for two days with a high cholesterol (HC diet. HC hepatocytes increased lipid and cholesterol content. HC diet sensitized hepatocytes to the toxic effect of ethanol and acetaldehyde. Cyp2E1 content increased with HC diet, as well as in those treated with ethanol or acetaldehyde, while the activity of this enzyme determined in microsomes increased in the HC and in all ethanol treated hepatocytes, HC and CW. Oxidized proteins were increased in the HC cultures treated or not with the toxins. Transmission electron microscopy showed endoplasmic reticulum (ER stress and megamitochondria in hepatocytes treated with ethanol as in HC and the ethanol HC treated hepatocytes. ER stress determined by PERK content was increased in ethanol treated hepatocytes from HC mice and CW. Nuclear translocation of ATF6 was observed in HC hepatocytes treated with ethanol, results that indicate that lipids overload and ethanol treatment favor ER stress. Oxidative stress, ER stress, and mitochondrial damage underlie potential mechanisms for increased damage in steatotic hepatocyte treated with ethanol.

  10. Cholesterol Enhances the Toxic Effect of Ethanol and Acetaldehyde in Primary Mouse Hepatocytes

    Science.gov (United States)

    López-Islas, Anayelly; Chagoya-Hazas, Victoria; Pérez-Aguilar, Benjamin; Palestino-Domínguez, Mayrel; Souza, Verónica; Miranda, Roxana U.; Bucio, Leticia; Gómez-Quiroz, Luis Enrique; Gutiérrez-Ruiz, María-Concepción

    2016-01-01

    Obesity and alcohol consumption are risk factors for hepatic steatosis, and both commonly coexist. Our objective was to evaluate the effect of ethanol and acetaldehyde on primary hepatocytes obtained from mice fed for two days with a high cholesterol (HC) diet. HC hepatocytes increased lipid and cholesterol content. HC diet sensitized hepatocytes to the toxic effect of ethanol and acetaldehyde. Cyp2E1 content increased with HC diet, as well as in those treated with ethanol or acetaldehyde, while the activity of this enzyme determined in microsomes increased in the HC and in all ethanol treated hepatocytes, HC and CW. Oxidized proteins were increased in the HC cultures treated or not with the toxins. Transmission electron microscopy showed endoplasmic reticulum (ER) stress and megamitochondria in hepatocytes treated with ethanol as in HC and the ethanol HC treated hepatocytes. ER stress determined by PERK content was increased in ethanol treated hepatocytes from HC mice and CW. Nuclear translocation of ATF6 was observed in HC hepatocytes treated with ethanol, results that indicate that lipids overload and ethanol treatment favor ER stress. Oxidative stress, ER stress, and mitochondrial damage underlie potential mechanisms for increased damage in steatotic hepatocyte treated with ethanol. PMID:26788255

  11. Transcriptional Regulation of Cytosolic Sulfotransferase 1C2 by Intermediates of the Cholesterol Biosynthetic Pathway in Primary Cultured Rat Hepatocytes.

    Science.gov (United States)

    Rondini, Elizabeth A; Pant, Asmita; Kocarek, Thomas A

    2015-12-01

    Cytosolic sulfotransferase 1C2 (SULT1C2) is expressed in the kidney, stomach, and liver of rats; however, the mechanisms regulating expression of this enzyme are not known. We evaluated transcriptional regulation of SULT1C2 by mevalonate (MVA)-derived intermediates in primary cultured rat hepatocytes using several cholesterol synthesis inhibitors. Blocking production of mevalonate with the 3-hydroxy-3-methylglutaryl-CoA reductase inhibitor pravastatin (30 μM), reduced SULT1C2 mRNA content by ∼40% whereas the squalene synthase inhibitor squalestatin (SQ1, 0.1 μM), which causes accumulation of nonsterol isoprenoids, increased mRNA content by 4-fold. Treatment with MVA (10 mM) strongly induced SULT1C2 mRNA by 12-fold, and this effect was blocked by inhibiting squalene epoxidase but not by more distal cholesterol inhibitors, indicating the effects of MVA are mediated by postsqualene metabolites. Using rapid amplification of cDNA ends (RACE), we characterized the 5' end of SULT1C2 mRNA and used this information to generate constructs for promoter analysis. SQ1 and MVA increased reporter activity by ∼1.6- and 3-fold, respectively, from a construct beginning 49 base pairs (bp) upstream from the longest 5'-RACE product (-3140:-49). Sequence deletions from this construct revealed a hepatocyte nuclear factor 1 (HNF1) element (-2558), and mutation of this element reduced basal (75%) and MVA-induced (30%) reporter activity and attenuated promoter activation following overexpression of HNF1α or 1β. However, the effects of SQ1 were localized to a more proximal promoter region (-281:-49). Collectively, our findings demonstrate that cholesterol biosynthetic intermediates influence SULT1C2 expression in rat primary hepatocytes. Further, HNF1 appears to play an important role in mediating basal and MVA-induced SULT1C2 transcription.

  12. Effect of Non-Esterified Fatty Acids on Fatty Acid Metabolism-Related Genes in Calf Hepatocytes Cultured in Vitro

    Directory of Open Access Journals (Sweden)

    Peng Li

    2013-11-01

    Full Text Available Background: NEFA plays numerous roles in the metabolism of glucose, lipids, and proteins. A number of experimental studies have shown that NEFA may have an important role in fatty acid metabolism in the liver, especially in dairy cows that experience negative energy balance (NEB during early lactation. Methods: In this study, using fluorescent quantitative RT-PCR, ELISA, and primary hepatocytes cultured in vitro, we examined the effect of NEFA (0, 0.2, 0.4, 0.8, 1.6, and 3.2 mmol/L on fatty acid metabolism by monitoring the mRNA and protein expression of the following key enzymes: long chain acyl-CoA synthetase (ACSL, carnitine palmitoyltransferase IA (CPT IA, long chain acyl-CoA dehydrogenase (ACADL, and acetyl-CoA carboxylase (ACC. Results: The mRNA and protein expression levels of ACSL and ACADL markedly increased as the concentration of NEFA in the media was increased. The mRNA and protein expression levels of CPT IA were enhanced significantly when the NEFA concentrations increased from 0 to 1.6 mmol/L and decreased significantly when the NEFA concentrations increased from 1.6 to 3.2 mmol/L. The mRNA and protein expression of ACC decreased gradually with increasing concentrations of NEFA. Conclusion: These findings indicate that increased NEFA significantly promote the activation and β-oxidation of fatty acids, but very high NEFA concentrations may inhibit the translocation of fatty acids into mitochondria of hepatocytes. This may explain the development of ketosis or liver lipidosis in dairy cows. CPT IA might be the key control enzyme of the fatty acid oxidation process in hepatocytes.

  13. Differential effects on apoptosis induction in hepatocyte lines by stable expression of hepatitis B virus X protein

    Institute of Scientific and Technical Information of China (English)

    Nicola Fiedler; Ellen Quant; Ludger Fink; Jianguang Sun; Ralph Schuster; Wolfram H Gerlich; Stephan Schaefer

    2006-01-01

    AIM: Hepatitis B virus protein X (HBx) has been shown to be weakly oncogenic in vitro. The transforming activities of HBx have been linked with the inhibition of several functions of the tumor suppressor p53. We have studied whether HBx may have different effects on p53 depending on the cell type.METHODS: We used the human hepatoma cell line HepG2 and the immortalized murine hepatocyte line AML12 and analyzed stably transfected clones which expressed physiological amounts of HBx. P53 was induced by UV irradiation.RESULTS: The p53 induction by UV irradiation was unaffected by stable expression of HBx. However, the expression of the cyclin kinase inhibitor p21waf/cip/sdi which gets activated by p53 was affected in the HBx transformed cell line AML12-HBx9, but not in HepG2.In AML-HBx9 cells, p21waf/cip/sdi-protein expression and p21waf/cip/sdi transcription were deregulated. Furthermore,the process of apoptosis was affected in opposite ways in the two cell lines investigated. While stable expression of HBx enhanced apoptosis induced by UV irradiation in HepG2-cells, apoptosis was decreased in HBx transformed AML12-HBx9. P53 repressed transcription from the HBV enhancer I, when expressed from expression vectors or after induction of endogenous p53 by UV irradiation.Repression by endogenous p53 was partially reversible by stably expressed HBx in both cell lines.CONCLUSION: Stable expression of HBx leads to deregulation of apoptosis induced by UV irradiation depending on the cell line used. In an immortalized hepatocyte line HBx acted anti-apoptotic whereas expression in a carcinoma derived hepatocyte line HBx enhanced apoptosis.

  14. Fas mRNA expression and calcium influx change in H2O2-induced apoptotic hepatocytes in vitro

    Institute of Scientific and Technical Information of China (English)

    Qi-Ping Lu; Lei Tian

    2005-01-01

    AIM: To investigate the relationship between Fas gene expression and calcium influx change in peroxide-induced apoptotic hepatocytes and the possible molecular mechanism of Rxa in protecting hepatocytes.METHODS: Single-cell Fas mRNA expression in H2O2-exposed L02 hepatocytes with or without treatment of Rxa,an extract from an anti-peroxidant, Radix Salviae Miltiorrhizae,was determined by all-cell patch clamp and single-cell reverse transcriptase polymerase chain reaction (RT-PCR). Transient calcium influx change ([Ca2+]i) in the cells was evaluated with all-cell patch clamp micro-fluorescence single-cytosolic free Ca2+ concentration technique. Fas protein expression, early apoptotic index (annexin-V+) and cell membrane change inthe cells were evaluated by immunohistochemistry, flow cytometry (FCM) and scan electron microscopy respectively.RESULTS: In cells exposed to H2O2 for 2 h, the specific lane for Fas mRNA was vivid on electrophoresis, with increased Fas protein expression, [Ca2+]i (from 143.66±34.21 to 1115.28±227.16), annexin-V+ index (from 4.00±0.79 to 16.18±0.72) and membrane vesicle formation. However, in cells exposed to H2O2 but pre-treated with Rxa, there was no increase in Fas mRNA or protein expression and [Ca2+]i (103.56±28.92). Annexin-V+ index (8.92±1.44) was lower than the controls (P<0.01), and the cell membrane was intact.CONCLUSION: H2O2 induces apoptosis of L02 cells by increasing cytosolic [Ca2+]i, and inducing Fas mRNA and protein expression. Rxa protects the L02 cells from apoptosis through anti-peroxidation, inhibition of calcium overloading and prevention of the activation of cytosolic Fas signal pathway.

  15. Effect of trifluoperazine on toxicity, HIF-1α induction and hepatocyte regeneration in acetaminophen toxicity in mice.

    Science.gov (United States)

    Chaudhuri, Shubhra; McCullough, Sandra S; Hennings, Leah; Brown, Aliza T; Li, Shun-Hwa; Simpson, Pippa M; Hinson, Jack A; James, Laura P

    2012-10-15

    Oxidative stress and mitochondrial permeability transition (MPT) are important mechanisms in acetaminophen (APAP) toxicity. The MPT inhibitor trifluoperazine (TFP) reduced MPT, oxidative stress, and toxicity in freshly isolated hepatocytes treated with APAP. Since hypoxia inducible factor-one alpha (HIF-1α) is induced very early in APAP toxicity, a role for oxidative stress in the induction has been postulated. In the present study, the effect of TFP on toxicity and HIF-1α induction in B6C3F1 male mice treated with APAP was examined. Mice received TFP (10mg/kg, oral gavage) prior to APAP (200mg/kg IP) and at 7 and 36h after APAP. Measures of metabolism (hepatic glutathione and APAP protein adducts) were comparable in the two groups of mice. Toxicity was decreased in the APAP/TFP mice at 2, 4, and 8h, compared to the APAP mice. At 24 and 48h, there were no significant differences in toxicity between the two groups. TFP lowered HIF-1α induction but also reduced the expression of proliferating cell nuclear antigen, a marker of hepatocyte regeneration. TFP can also inhibit phospholipase A(2), and cytosolic and secretory PLA(2) activity levels were reduced in the APAP/TFP mice compared to the APAP mice. TFP also lowered prostaglandin E(2) expression, a known mechanism of cytoprotection. In summary, the MPT inhibitor TFP delayed the onset of toxicity and lowered HIF-1α induction in APAP treated mice. TFP also reduced PGE(2) expression and hepatocyte regeneration, likely through a mechanism involving PLA(2).

  16. The neuronal nitric oxide synthase inhibitor NANT blocks acetaminophen toxicity and protein nitration in freshly isolated hepatocytes.

    Science.gov (United States)

    Banerjee, Sudip; Melnyk, Stepan B; Krager, Kimberly J; Aykin-Burns, Nukhet; Letzig, Lynda G; James, Laura P; Hinson, Jack A

    2015-12-01

    3-Nitrotyrosine (3NT) in liver proteins of mice treated with hepatotoxic doses of acetaminophen (APAP) has been postulated to be causative in toxicity. Nitration is by a reactive nitrogen species formed from nitric oxide (NO). The source of the NO is unclear. iNOS knockout mice were previously found to be equally susceptible to APAP toxicity as wildtype mice and iNOS inhibitors did not decrease toxicity in mice or in hepatocytes. In this work we examined the potential role of nNOS in APAP toxicity in hepatocytes using the specific nNOS inhibitor NANT (10 µM)(N-[(4S)-4-amino-5-[(2-aminoethyl)amino]pentyl]-N'-nitroguanidinetris (trifluoroacetate)). Primary hepatocytes (1 million/ml) from male B6C3F1 mice were incubated with APAP (1mM). Cells were removed and assayed spectrofluorometrically for reactive nitrogen and oxygen species using diaminofluorescein (DAF) and Mitosox red, respectively. Cytotoxicity was determined by LDH release into media. Glutathione (GSH, GSSG), 3NT, GSNO, acetaminophen-cysteine adducts, NAD, and NADH were measured by HPLC. APAP significantly increased cytotoxicity at 1.5-3.0 h. The increase was blocked by NANT. NANT did not alter APAP mediated GSH depletion or acetaminophen-cysteine adducts in proteins which indicated that NANT did not inhibit metabolism. APAP significantly increased spectroflurometric evidence of reactive nitrogen and oxygen formation at 0.5 and 1.0 h, respectively, and increased 3NT and GSNO at 1.5-3.0 h. These increases were blocked by NANT. APAP dramatically increased NADH from 0.5-3.0 h and this increase was blocked by NANT. Also, APAP decreased the Oxygen Consumption Rate (OCR), decreased ATP production, and caused a loss of mitochondrial membrane potential, which were all blocked by NANT.

  17. Effects of aminoguanidine on nitric oxide production induced by inflammatory cytokines and endotoxin in cultured rat hepatocytes

    Institute of Scientific and Technical Information of China (English)

    Guo Liang Zhang; Ye Hong Wang; Hui Ling Teng; Zhi Bin Lin

    2001-01-01

    AIM To study the effects of aminoguanidine(AG) and two L-arginine analogues Nω-nitro-L-arginine methyl ester (L-NAME) and Nω-nitro-L-arginine (L-NNA) on nitric oxide (NO) productioninduced by cytokines (TNF-α, IL-11β, and IFN-γ)and bacterial lipopolysaccharide (LPS) mixture(CM) in the cultured rat hepatocytes, andexamine their mechanisms action.METHODS Rat hepatocytes were incubatedwith AG, L-NAME, L-NNA, Actinomycin D (ActD)and dexamethasene in a medium containing CM(LPS plus TNF-α, IL-1β, and IFN-γ) for 24 h. NOproduction in the cultured supernatant wasmeasured with the Griese reaction. IntracellularcGMP level was detected with radioimmunoasey.RESULTS NO production was markedlyblocked by AG and L-NAME in a dose-dependentmanner under inflammatory stimuli conditiontriggered by CM in vitro. The rate of themaximum inhibitory effects of L-NAME (38.9%)was less potent than that obtained with AG(53.7%, P<0.05). There was no significantdifference between the inhibitory effects of AGand two L-arginine analogues on intracellularcGMP accumulation in rat cultured hepatocytes.Non-specific NOS expression inhibitordexamethasone ( DEX ) and iNOS mRNAtranscriptional inhibitor ActD also significantlyinhibited CM-induced NO production. AG(0.1mmol.L-1) and ActD (0.2ng@Lt) wereequipotent in decreasing NO production inducedby inflammatory stimuli in vitro, and botheffects were more potent than that induced bynon-selectivity NOS activity inhibitor L-NAME(0. 1 mmol@ L- 1) under similar stimuli conditions(P<O.O1).CONCLUSION AG is a potent selectiveinhibitor of inducible isoform of NOS, and themechanism of action may be not onlycompetitive inhibition in the substrate level, butalso the gene expression level in rathepatocytes .

  18. Mapping the Cell-Surface N-Glycoproteome of Human Hepatocytes Reveals Markers for Selecting a Homogeneous Population of iPSC-Derived Hepatocytes.

    Science.gov (United States)

    Mallanna, Sunil K; Cayo, Max A; Twaroski, Kirk; Gundry, Rebekah L; Duncan, Stephen A

    2016-09-13

    When comparing hepatic phenotypes between iPSC-derived hepatocyte-like cells from different liver disease patients, cell heterogeneity can confound interpretation. We proposed that homogeneous cell populations could be generated by fluorescence-activated cell sorting (FACS). Using cell-surface capture proteomics, we identified a total of 300 glycoproteins on hepatocytes. Analyses of the expression profiles during the differentiation of iPSCs revealed that SLC10A1, CLRN3, and AADAC were highly enriched during the final stages of hepatocyte differentiation. FACS purification of hepatocyte-like cells expressing SLC10A1, CLRN3, or AADAC demonstrated enrichment of cells with hepatocyte characteristics. Moreover, transcriptome analyses revealed that cells expressing the liver gene regulatory network were enriched while cells expressing a pluripotent stem cell network were depleted. In conclusion, we report an extensive catalog of cell-surface N-linked glycoproteins expressed in primary hepatocytes and identify cell-surface proteins that facilitate the purification of homogeneous populations of iPSC-derived hepatocyte-like cells.

  19. Mapping the Cell-Surface N-Glycoproteome of Human Hepatocytes Reveals Markers for Selecting a Homogeneous Population of iPSC-Derived Hepatocytes

    Directory of Open Access Journals (Sweden)

    Sunil K. Mallanna

    2016-09-01

    Full Text Available When comparing hepatic phenotypes between iPSC-derived hepatocyte-like cells from different liver disease patients, cell heterogeneity can confound interpretation. We proposed that homogeneous cell populations could be generated by fluorescence-activated cell sorting (FACS. Using cell-surface capture proteomics, we identified a total of 300 glycoproteins on hepatocytes. Analyses of the expression profiles during the differentiation of iPSCs revealed that SLC10A1, CLRN3, and AADAC were highly enriched during the final stages of hepatocyte differentiation. FACS purification of hepatocyte-like cells expressing SLC10A1, CLRN3, or AADAC demonstrated enrichment of cells with hepatocyte characteristics. Moreover, transcriptome analyses revealed that cells expressing the liver gene regulatory network were enriched while cells expressing a pluripotent stem cell network were depleted. In conclusion, we report an extensive catalog of cell-surface N-linked glycoproteins expressed in primary hepatocytes and identify cell-surface proteins that facilitate the purification of homogeneous populations of iPSC-derived hepatocyte-like cells.

  20. Evaluation of UGT protein interactions in human hepatocytes: effect of siRNA down regulation of UGT1A9 and UGT2B7 on propofol glucuronidation in human hepatocytes.

    Science.gov (United States)

    Konopnicki, Camille M; Dickmann, Leslie J; Tracy, Jeffrey M; Tukey, Robert H; Wienkers, Larry C; Foti, Robert S

    2013-07-15

    Previous experiments performed in recombinant systems have suggested that protein-protein interactions occur between the UGTs and may play a significant role in modulating enzyme activity. However, evidence of UGT protein-protein interactions either in vivo or in more physiologically relevant in vitro systems has yet to be demonstrated. In this study, we examined oligomerization and its ability to affect glucuronidation in plated human hepatocytes. siRNA down regulation experiments and activity studies were used to examine changes in metabolite formation of one UGT isoform due to down regulation of a second UGT isoform. Selective siRNA directed towards UGT1A9 or UGT2B7 resulted in significant and selective decreases in their respective mRNA levels. As expected, the metabolism of the UGT1A9 substrate propofol decreased with UGT1A9 down regulation. Interestingly, UGT1A9 activity, but not UGT1A9 mRNA expression, was also diminished when UGT2B7 expression was selectively inhibited, implying potential interactions between the two isoforms. Minor changes to UGT1A4, UGT2B4 and UGT2B7 activity were also observed when UGT1A9 expression was selectively down regulated. To our knowledge, this represents the first piece of evidence that UGT protein-protein interactions occur in human hepatocytes and suggests that expression levels of UGT2B7 may directly impact the glucuronidation activity of selective UGT1A9 substrates.

  1. Contextualizing Hepatocyte Functionality of Cryopreserved HepaRG Cell Cultures.

    Science.gov (United States)

    Jackson, Jonathan P; Li, Linhou; Chamberlain, Erica D; Wang, Hongbing; Ferguson, Stephen S

    2016-09-01

    Over the last decade HepaRG cells have emerged as a promising alternative to primary human hepatocytes (PHH) and have been featured in over 300 research publications. Most of these reports employed freshly differentiated HepaRG cells that require time-consuming culture (∼28 days) for full differentiation. Recently, a cryopreserved, predifferentiated format of HepaRG cells (termed here "cryo-HepaRG") has emerged as a new model that improves global availability and experimental flexibility; however, it is largely unknown whether HepaRG cells in this format fully retain their hepatic characteristics. Therefore, we systematically investigated the hepatocyte functionality of cryo-HepaRG cultures in context with the range of interindividual variation observed with PHH in both sandwich-culture and suspension formats. These evaluations uncovered a novel adaptation period for the cryo-HepaRG format and demonstrated the impact of extracellular matrix on cryo-HepaRG functionality. Pharmacologically important drug-metabolizing alleles were genotyped in HepaRG cells and poor metabolizer alleles for CYP2D6, CYP2C9, and CYP3A5 were identified and consistent with higher frequency alleles found in individuals of Caucasian decent. We observed liver enzyme inducibility with aryl hydrocarbon receptor, constitutive androstane receptor (CAR), and pregnane X receptor activators comparable to that of sandwich-cultured PHH. Finally, we show for the first time that cryo-HepaRG supports proper CAR cytosolic sequestration and translocation to hepatocyte nuclei in response to phenobarbital treatment. Taken together, these data reveal important considerations for the use of this cell model and demonstrate that cryo-HepaRG are suitable for metabolism and toxicology screening.

  2. Effects of ethanol on antioxidant capacity in isolated rat hepatocytes

    Institute of Scientific and Technical Information of China (English)

    Sien-Sing Yang; Chi-Chang Huang; Jiun-Rong Chen; Che-Lin Chiu; Ming-Jer Shieh; Su-Jiun Lin; Suh-Ching Yang

    2005-01-01

    AIM: To investigate dose-response and time-course of the effects of ethanol on the cell viability and antioxidant capacity in isolated rat hepatocytes.METHODS: Hepatocytes were isolated from male adult Wistar rats and seeded into 100-mm dishes. Hepatocytes were treated with ethanol at concentrations between 0 (C), 10 (E10), 50 (E50), and 100 (E100) mmol/L (dose response) for 12, 24, and 36 h (time course). Then,lactate dehydrogenase (LDH) leakage, malondialdehyde (MDA) concentration, glutathione (GSH) level, and activities of glutathione peroxidase (GPX), glutathione reductase (GRD), superoxide dismutase (SOD), and catalase (CAT) were measured.RESULTS: Our data revealed that LDH leakage was significantly increased by about 30% in group E100 over those in groups C and E10 at 24 and 36 h, The MDA concentration in groups C, E10 and E50 were significantly lower than that in group E100 at 36 h. Furthermore,the concentration of MDA in group E100 at 36 h was significantly higher by 4.5- and 1.7-fold, respectively,than that at 12 and 24 h. On the other hand, the GSH level in group E100 at 24 and 36 h was significantly decreased, by 32% and 28%, respectively, compared to that at 12 h. The activities of GRD and CAT in group E100 at 36 h were significantly less than those in groups C and E10. However, The GPX and SOD activities showed no significant change in each group.CONCLUSION: These results suggest that longtime incubation with higher concentration of ethanol (100 mmol/L) decreased the cell viability by means of reducing GRD and CAT activities and increasing lipid peroxidation.

  3. Effects of eugenol on hepatic glucose production and AMPK signaling pathway in hepatocytes and C57BL/6J mice.

    Science.gov (United States)

    Jeong, Kyong Ju; Kim, Do Yeon; Quan, Hai-Yan; Jo, Hee Kyung; Kim, Go Woon; Chung, Sung Hyun

    2014-03-01

    Eugenol is a phenylpropanoid with many pharmacological activities, but its anti-hyperglycemic activity is not yet fully explored. For in vitro study, HepG2 cells and primary rat hepatocytes were used, and glucose production was induced by adding 100 nM of glucagon in the presence of gluconeogenic substrates. In animal study, hyperglycemia was induced by high fat diet (HFD) in male C57BL/6J mice, and eugenol was orally administered at 20 or 40 mg per kg (E20, E40) for 15 weeks. Eugenol significantly inhibited glucagon-induced glucose production and phosphorylated AMPK in the HepG2 and primary rat hepatocytes, and these effects were reversed in the presence of compound C (an AMPK inhibitor) or STO-609 (a CAMKK inhibitor). In addition, the protein and gene expression levels of CREB, CRTC2·CREB complex, PGC-1α, PEPCK and G6Pase were all significantly suppressed. Moreover, inhibition of AMPK by over-expression of dominant negative AMPK prevented eugenol from suppressions of gluconeogenic gene expression and hepatic glucose production. In animal study, plasma glucose and insulin levels of the E40 group were decreased by 31% and 63%, respectively, when compared to those of HFD control. In pyruvate tolerance tests, pyruvate-induced glucose excursions were decreased, indicating that the anti-hyperglycemic activity of eugenol is primarily due to the suppression of hepatic gluconeogenesis. In summary, eugenol effectively ameliorates hyperglycemia through inhibition of hepatic gluconeogenesis via modulating CAMKK-AMPK-CREB signaling pathway. Eugenol or eugenol-containing medicinal plants could represent a promising therapeutic agent to prevent type 2 diabetes.

  4. Extra virgin olive oil phenols down-regulate lipid synthesis in primary-cultured rat-hepatocytes.

    Science.gov (United States)

    Priore, Paola; Siculella, Luisa; Gnoni, Gabriele Vincenzo

    2014-07-01

    Hydroxytyrosol, tyrosol, and oleuropein, the main phenols present in extra virgin olive oil, have been reported to exert several biochemical and pharmacological effects. Here, we investigated the short-term effects of these compounds on lipid synthesis in primary-cultured rat-liver cells. Hydroxytyrosol, tyrosol and oleuropein inhibited both de novo fatty acid and cholesterol syntheses without an effect on cell viability. The inhibitory effect of individual compounds was already evident within 2 h of 25 μM phenol addition to the hepatocytes. The degree of cholesterogenesis reduction was similar for all phenol treatments (-25/30%), while fatty acid synthesis showed the following order of inhibition: hydroxytyrosol (-49%) = oleuropein (-48%) > tyrosol (-30%). A phenol-induced reduction of triglyceride synthesis was also detected. To clarify the lipid-lowering mechanism of these compounds, their influence on the activity of key enzymes of fatty acid biosynthesis (acetyl-CoA carboxylase and fatty acid synthase), triglyceride synthesis (diacylglycerol acyltransferase) and cholesterogenesis (3-hydroxy-3-methyl-glutaryl-CoA reductase) was investigated in situ by using digitonin-permeabilized hepatocytes. Acetyl-CoA carboxylase, diacylglycerol acyltransferase and 3-hydroxy-3-methyl-glutaryl-CoA reductase activities were reduced after 2 h of 25 μM phenol treatment. No change in fatty acid synthase activity was observed. Acetyl-CoA carboxylase inhibition (hydroxytyrosol, -41%, = oleuropein, -38%, > tyrosol, -17%) appears to be mediated by phosphorylation of AMP-activated protein kinase. These findings suggest that a decrease in hepatic lipid synthesis may represent a potential mechanism underlying the reported hypolipidemic effect of phenols of extra virgin olive oil.

  5. Insulin infusion reduces hepatocyte growth factor in lean humans

    DEFF Research Database (Denmark)

    de Courten, Barbora; de Courten, Maximilian; Dougherty, Sonia;

    2013-01-01

    OBJECTIVE: Plasma Hepatocyte Growth Factor (HGF) is significantly elevated in obesity and may contribute to vascular disease, metabolic syndrome or cancer in obese individuals. The current studies were done to determine if hyperinsulinemia increases plasma HGF. MATERIALS/METHODS: Twenty......-two participants (10 women/12 men, BMI 20.6-34.5 kg/m(2), age 18-49 years) underwent a hyperinsulinemic euglycemic clamp with measurement of HGF at baseline and steady state. Relationships between baseline HGF, anthropometrics, triglycerides, liver enzymes, c-reactive protein and adiponectin were also evaluated...

  6. Prolyl-4-Hydroxylase 2 Potentially Contributes to Hepatocellular Carcinoma-Associated Erythrocytosis by Maintaining Hepatocyte Nuclear Factor-4α Expression

    Directory of Open Access Journals (Sweden)

    Wenwen Sun

    2015-12-01

    Full Text Available Background: Increased red blood cell count (Erythrocytosis is an important paraneoplastic syndrome of hepatocellular carcinoma (HCC and is a significant risk factor for lethal lung artery thromboembolism. HCC-associated erythrocytosis is partially caused by the ability of several HCC cells to produce erythropoietin (EPO. Prolyl-4-hydroxylase 2 (PHD2 is an enzyme encoded by the gene EGLN1. The best-known function of PHD2 is to mediate the oxygen-dependent degradation of the labile α-subunit of hypoxia-inducible factor (HIF. However, there is increasing evidence that PHD2 also regulates HIF-independent pathways by interacting with other substrates. Methods: In the EPO-producing human HCC cell line HepG2, the expression of PHD2 gene was silenced with siRNA. EPO production was estimated using quantitative PCR and ELISA. Results: In HepG2 cells, PHD2 suppresses the activity of TGF-β1 pathway and consequently maintains the expression of hepatocyte nuclear factor-4α (HNF-4α, an important transcription factor promoting the EPO expression in hepatocytes. PHD2 knockdown caused a marked reduction of EPO production. HIF seemed not to be involved in this biology. Conclusion: Our findings show that PHD2 represents a potential contributing factor for HCC-associated erythrocytosis. Selective inhibition of PHD2 in HCC cells might be considered as a new way to manage erythrocytosis in HCC patients.

  7. Pravastatin transport across the hepatocyte canalicular membrane requires both ATP and a transmembrane pH gradient.

    Science.gov (United States)

    Adachi, Y; Okuyama, Y; Miya, H; Matsusita, H; Kitano, M; Kamisako, T; Yamamoto, T

    1996-06-01

    Hepatic excretion of non-bile acid organic anions is reported to be ATP-dependent and a defect of this transport has been reported in congenitally jaundiced rats, animal models of human Dubin-Johnson syndrome. To investigate the effect of the transmembrane pH gradient on hepatocyte canalicular membrane transport of ATP-dependent organic anions, uptake of pravastatin, a 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase-inhibiting organic anion, by hepatocyte canalicular membrane vesicles was observed in the presence or absence of transmembrane pH gradients. Uptake was assessed by a rapid filtration technique. ATP-dependent pravastatin uptake was stimulated in the presence of a transmembrane pH gradient (in > out) in Sprague-Dawley (SD) rats. Uptake was dependent on both pravastatin and ATP concentrations and showed saturation kinetics. After intravenous injection of [14C]-pravastatin (0.3 mumol), 81% of the dose was excreted in the bile within 35 min in SD rats, whereas only 20% was excreted in the bile in Eisai hyperbilirubinuria rats. ATP and the pH gradient also co-stimulated the uptake of pravastatin in Eisai hyperbilirubinuria rats, although the K(m) was much higher and Vmax was much lower than corresponding values in SD rats. This coincided well with the marked reduction in vivo biliary excretion of pravastatin in jaundiced rats.

  8. Pharmacokinetics and effects on serum cholinesterase activities of organophosphorus pesticides acephate and chlorpyrifos in chimeric mice transplanted with human hepatocytes.

    Science.gov (United States)

    Suemizu, Hiroshi; Sota, Shigeto; Kuronuma, Miyuki; Shimizu, Makiko; Yamazaki, Hiroshi

    2014-11-01

    Organophosphorus pesticides acephate and chlorpyrifos in foods have potential to impact human health. The aim of the current study was to investigate the pharmacokinetics of acephate and chlorpyrifos orally administered at lowest-observed-adverse-effect-level doses in chimeric mice transplanted with human hepatocytes. Absorbed acephate and its metabolite methamidophos were detected in serum from wild type mice and chimeric mice orally administered 150mg/kg. Approximately 70% inhibition of cholinesterase was evident in plasma of chimeric mice with humanized liver (which have higher serum cholinesterase activities than wild type mice) 1day after oral administrations of acephate. Adjusted animal biomonitoring equivalents from chimeric mice studies were scaled to human biomonitoring equivalents using known species allometric scaling factors and in vitro metabolic clearance data with a simple physiologically based pharmacokinetic (PBPK) model. Estimated plasma concentrations of acephate and chlorpyrifos in humans were consistent with reported concentrations. Acephate cleared similarly in humans and chimeric mice but accidental/incidental overdose levels of chlorpyrifos cleared (dependent on liver metabolism) more slowly from plasma in humans than it did in mice. The data presented here illustrate how chimeric mice transplanted with human hepatocytes in combination with a simple PBPK model can assist evaluations of toxicological potential of organophosphorus pesticides.

  9. Endocytosis via galactose receptors in vivo. Ligand size directs uptake by hepatocytes and/or liver macrophages

    Energy Technology Data Exchange (ETDEWEB)

    Schlepper-Schaefer, J.; Huelsmann, D.; Djovkar, A.; Meyer, H.E.; Herbertz, L.; Kolb, H.; Kolb-Bachofen, V.

    1986-01-01

    The intrahepatic binding and uptake of variously sized ligands with terminal galactosyl residues is rat liver was followed. The ligands were administered to prefixed livers in binding studies and in vivo and in situ (serum-free perfused livers) in uptake studies. Gold sols with different particle diameters were prepared: 5 nm (Au/sub 5/), 17 nm (Au/sub 17/), 50 nm (Au/sub 50/) and coated with galactose exposing glycoproteins (asialofetuin (ASF) or lactosylated BSA (LacBSA)). Electron microscopy of mildly prefixed livers perfused with LacBSA-Au/sub 5/ in serum-free medium showed ligand binding to liver macrophages, hepatocytes and endothelial cells. Ligands bound to prefixed cell surfaces reflect the initial distribution of receptor activity: pre-aggregated clusters of ligands are found on liver macrophages, single particles statistically distributed on hepatocytes and pre-aggregated clusters of particles restricted to coated pits on endothelial cells. Ligand binding is prevented in the presence of 80 mM N-acetylgalactosamine (GalNAc), while N-acetylglucosamine (GlcNAc) is without effect. Electron microscopy of livers after ligand injection into the tail vein shows that in vivo uptake of electron-dense galactose particles by liver cells is size-dependent. In vivo uptake by liver macrophages is mediated by galactose-specific recognition as shown by inhibition with GalNAc.

  10. Purinergic receptor functionality is necessary for infection of human hepatocytes by hepatitis delta virus and hepatitis B virus.

    Directory of Open Access Journals (Sweden)

    John M Taylor

    Full Text Available Hepatitis B virus (HBV and hepatitis delta virus (HDV are major sources of acute and chronic hepatitis. HDV requires the envelope proteins of HBV for the processes of assembly and infection of new cells. Both viruses are able to infect hepatocytes though previous studies have failed to determine the mechanism of entry into such cells. This study began with evidence that suramin, a symmetrical hexasulfated napthylurea, could block HDV entry into primary human hepatocytes (PHH and was then extrapolated to incorporate findings of others that suramin is one of many compounds that can block activation of purinergic receptors. Thus other inhibitors, pyridoxal-phosphate-6-azophenyl-2',4'-disulfonate (PPADS and brilliant blue G (BBG, both structurally unrelated to suramin, were tested and found to inhibit HDV and HBV infections of PHH. BBG, unlike suramin and PPADS, is known to be more specific for just one purinergic receptor, P2X7. These studies provide the first evidence that purinergic receptor functionality is necessary for virus entry. Furthermore, since P2X7 activation is known to be a major component of inflammatory responses, it is proposed that HDV and HBV attachment to susceptible cells, might also contribute to inflammation in the liver, that is, hepatitis.

  11. Identiifcation of Human Hepatocyte Proliferation Related Gene C2orf69

    Institute of Scientific and Technical Information of China (English)

    Ren-wen Zhang; Yong Qiao; Xiao-hua Hao; Hong-min Li; Hui Ren; Xiao-jing Zhang; Hong-shan Wei; Xiao-yuan Xu

    2014-01-01

    Objective To construct the prokaryotic expression vector pET-32a(+)-C2orf69 and induce the expression of recombinant proteins in vitro. Then the possible effects of recombinant protein on cell proliferation was observed and rabbit-anti-C2orf69 protein polyclonal antibodies was obtained. Methods Gene fragment of C2orf69 was ampliifed by PCR and then prokaryotic expression plasmid pET-32a(+)-C2orf69 was constructed. Recombinant protein C2orf69 expression was identiifed by SDS-PAGE and Western blot. The white-ear rabbits were immunized with purified recombinant protein C2orf69, and the potency and speciifcity of polyclonal antibody were evaluated by enzyme-linked immunosorbent assay (ELISA) and Western blot. Also, different liver cells were incubated with recombinant protein C2orf69 in vitro. Results C2orf69 gene fragment was successfully ampliifed, results of gene sequencing were consistent with the sequence in GenBank. Recombinant protein of C2orf69 was successfully induced and expressed. The polyclonal antibody titer was up to 1︰1 280 000 through enzyme-linked immunosorbent assay. Results of cell proliferation showed that the recombinant protein could inhibit the proliferation of different liver cells. Conclusions The recombinant protein C2orf69 could inhibit the proliferation of different liver cells, and we speculated that it may be a widely roled inhibitor of hepatocyte proliferation. Our experiment showed that the proliferation inhibition of cells may be realized by G1 phase extending and S phase shortening.

  12. Effects of nuclear translocation of tissue transglutaminase and the release of cytochrome C on hepatocyte apoptosis

    Institute of Scientific and Technical Information of China (English)

    宋良文; 马宪梅; 李扬; 崔雪梅; 王晓民

    2003-01-01

    Objective To assess the effects of nuclear translocation of tissue transglutaminase (TTG) and the release of cytochrome C on hepatocyte apoptosis and to reveal the mechanism of signal transduction of early apoptosis in injured hepatocytes. Methods Hepatocytes isolated from tissue transglutaminase gene knock-out rats and mice were stimulated with ethanol. Proteins from whole cell, cytoplasm and nuclei were extracted for determination of TTG activity by 14 C-putrescine incorporation. Distribution of TTG throughout the entire cell, as well as just nucleus was observed under a confocal scanning microscope. The amount of cytochrome C released from mitochondria was determined by ELISA. Cell apoptosis was observed by fluorescent cytochemistry.Results TTG activity in whole cells and nuclei was significantly increased after the hepatocytes were treated with ethanol. Cytochrome C release was remarkably increased in the cells isolated from rat and wild-type mouse after treatment with ethanol but not in TTG gene knock-out mice. Cellular apoptosis appeared in hepatocytes isolated from rats and wild-type mice but not in the hepatocytes from TTG gene knock-out mice after stimulation with ethanol.Conclusions Increased TTG in hepatocytes can be translocated into the nucleus and promote release of mitochondrial cytochrome C into the cytoplasm. Passing through a series of signal pathways, hepatocyte apoptosis is induced eventually.

  13. A dual-functional fibrous scaffold enhances P450 activity of cultured primary rat hepatocytes.

    Science.gov (United States)

    Chua, Kian-Ngiap; Tang, Yen-Ni; Quek, Chai-Hoon; Ramakrishna, Seeram; Leong, Kam W; Mao, Hai-Quan

    2007-09-01

    We have designed a novel dual-functional electrospun fibrous scaffold comprising two fiber mesh layers that were modified differently to induce two separate biological responses from hepatocytes. The first fiber layer was galactosylated on the surface to mediate hepatocyte attachment, while the second layer was loaded with 3-methylcholanthrene (3-Mc) to enhance cytochrome P450 activity of hepatocytes. Primary rat hepatocytes cultured on the galactosylated fibrous scaffolds loaded with different concentrations of 3-Mc were compared for their cell attachment efficiency, albumin secretion activity and cytochrome P450-dependent 7-ethoxycoumarin O-deethylase activity. This hybrid fibrous scaffold mediated hepatocyte attachment with slightly lower efficiency (76+/-2.3%) than a single-layer galactosylated fibrous scaffold (84+/-3.5%). More importantly, the cytochrome P450 activity of the hepatocytes cultured on the hybrid scaffold correlated well with the 3-Mc loading level. The results also showed that transfer of 3-Mc to hepatocytes through direct cell-fiber contact was the dominant transport route, with the induced cytochrome P450 activity being 1.9- to 4.8-fold higher than that of transfer of 3-Mc to hepatocytes via dissolution from fibers to medium. This study demonstrates the feasibility of creating multi-functional fibrous scaffolds that serve both as an adhesive substrate and as a delivery vehicle for bioactive molecules.

  14. A sandwich-cultured rat hepatocyte system with increased metabolic competence evaluated by gene expression profiling

    NARCIS (Netherlands)

    Kienhuis, A.S.; Wortelboer, H.M.; Maas, W.J.; Herwijnen, M. van; Kleinjans, J.C.S.; Delft, J.H.M. van; Stierum, R.H.

    2007-01-01

    A rapid decline of cytochrome P450 (CYP450) enzyme activities remains a drawback of rat hepatocyte-based in vitro cultures. Consequently, judgment of the toxic potential of compounds that need bioactivation by CYP450s may not be adequate using this model. In the present study, an improved hepatocyte

  15. Partial hepatectomy induces delayed hepatocyte proliferation and normal liver regeneration in ovariectomized mice

    Directory of Open Access Journals (Sweden)

    Umeda M

    2015-07-01

    Full Text Available Makoto Umeda,1 Masaki Hiramoto,1,2 Takeshi Imai1 1Department of Aging Intervention, National Center for Geriatrics and Gerontology, Obu, Aichi, Japan; 2Department of Biochemistry, Tokyo Medical University, Tokyo, Japan Abstract: Estrogens play central roles in sexual development, reproduction, and hepatocyte proliferation. The ovaries are one of the main organs for estradiol (E2 production. Ovariectomies (OVXs were performed on the female mice, and hepatocyte proliferation was analyzed. The ovariectomized mice exhibited delayed hepatocyte proliferation after partial hepatectomy (PH and also exhibited delayed and reduced E2 induction. Both E2 administration and PH induced the gene expression of estrogen receptor α (ERα. The transcripts of ERα were detected specifically in periportal hepatocytes after E2 administration and PH. Moreover, the E2 concentrations and hepatocyte proliferation rates were highest in the proestrus period of the estrous cycle. Taken together, these findings indicate that E2 accelerated ERα expression in periportal hepatocytes and hepatocyte proliferation in the female mice.Keywords: estrogen, ER, estrous cycle, hepatocyte proliferation, liver regeneration

  16. Fagopyrum tataricum (Buckwheat Improved High-Glucose-Induced Insulin Resistance in Mouse Hepatocytes and Diabetes in Fructose-Rich Diet-Induced Mice

    Directory of Open Access Journals (Sweden)

    Chia-Chen Lee

    2012-01-01

    Full Text Available Fagopyrum tataricum (buckwheat is used for the treatment of type 2 diabetes mellitus in Taiwan. This study was to evaluate the antihyperglycemic and anti-insulin resistance effects of 75% ethanol extracts of buckwheat (EEB in FL83B hepatocytes by high-glucose (33 mM induction and in C57BL/6 mice by fructose-rich diet (FRD; 60% induction. The active compounds of EEB (100 μg/mL; 50 mg/kg bw, quercetin (6 μg/mL; 3 mg/kg bw, and rutin (23 μg/mL; 11.5 mg/kg bw were also employed to treat FL83B hepatocytes and animal. Results indicated that EEB, rutin, and quercetin + rutin significantly improved 2-NBDG uptake via promoting Akt phosphorylation and preventing PPARγ degradation caused by high-glucose induction for 48 h in FL83B hepatocytes. We also found that EEB could elevate hepatic antioxidant enzymes activities to attenuate insulin resistance as well as its antioxidation caused by rutin and quercetin. Finally, EEB also inhibited increases in blood glucose and insulin levels of C57BL/6 mice induced by FRD.

  17. Fagopyrum tataricum (buckwheat) improved high-glucose-induced insulin resistance in mouse hepatocytes and diabetes in fructose-rich diet-induced mice.

    Science.gov (United States)

    Lee, Chia-Chen; Hsu, Wei-Hsuan; Shen, Siou-Ru; Cheng, Yu-Hsiang; Wu, She-Ching

    2012-01-01

    Fagopyrum tataricum (buckwheat) is used for the treatment of type 2 diabetes mellitus in Taiwan. This study was to evaluate the antihyperglycemic and anti-insulin resistance effects of 75% ethanol extracts of buckwheat (EEB) in FL83B hepatocytes by high-glucose (33 mM) induction and in C57BL/6 mice by fructose-rich diet (FRD; 60%) induction. The active compounds of EEB (100 μg/mL; 50 mg/kg bw), quercetin (6 μg/mL; 3 mg/kg bw), and rutin (23 μg/mL; 11.5 mg/kg bw) were also employed to treat FL83B hepatocytes and animal. Results indicated that EEB, rutin, and quercetin + rutin significantly improved 2-NBDG uptake via promoting Akt phosphorylation and preventing PPARγ degradation caused by high-glucose induction for 48 h in FL83B hepatocytes. We also found that EEB could elevate hepatic antioxidant enzymes activities to attenuate insulin resistance as well as its antioxidation caused by rutin and quercetin. Finally, EEB also inhibited increases in blood glucose and insulin levels of C57BL/6 mice induced by FRD.

  18. The dipeptide Pro-Asp promotes IGF-1 secretion and expression in hepatocytes by enhancing JAK2/STAT5 signaling pathway.

    Science.gov (United States)

    Wang, Songbo; Wang, Guoqing; Zhang, Mengyuan; Zhuang, Lu; Wan, Xiaojuan; Xu, Jingren; Wang, Lina; Zhu, Xiaotong; Gao, Ping; Xi, Qianyun; Zhang, Yongliang; Shu, Gang; Jiang, Qingyan

    2016-11-15

    It has been implicated that IGF-1 secretion can be regulated by dietary protein. However, whether the dipeptides, one of digested products of dietary protein, have influence on IGF-1 secretion remain largely unknown. Our study aimed to investigate the effects of the dipeptide Pro-Asp on IGF-1 secretion and expression in hepatocytes and to explore the possible underlying mechanisms. Our findings demonstrated that Pro-Asp promoted the secretion and gene expression of IGF-1 in HepG2 cells and primary porcine hepatocytes. Meanwhile, Pro-Asp activated the ERK and Akt signaling pathways, downstream of IGF-1. In addition, Pro-Asp enhanced GH-mediated JAK2/STAT5 signaling pathway, while inhibition of JAK2/STAT5 blocked the promotive effect of Pro-Asp on IGF-1 secretion and expression. Moreover, acute injection of Pro-Asp stimulated IGF-1 expression and activated JAK2/STAT5 signaling pathway in mice liver. Together, these results suggested that the dipeptide Pro-Asp promoted IGF-1 secretion and expression in hepatocytes by enhancing GH-mediated JAK2/STAT5 signaling pathway.

  19. Prolonged Survival of Mice with Acute Liver Failure with Transplantation of Monkey Hepatocytes Cultured with an Antiapoptotic Pentapeptide V5

    OpenAIRE

    田中, 公章

    2007-01-01

    BACKGROUND: Because hepatocyte transplantation has been considered to be an attractive method to treat acute liver failure (ALF), efficient recovery of hepatocytes and maintenance of differentiated hepatocyte functions is of extreme importance. We here report the usefulness of an antiapoptotic pentapeptide V5, composed of Val-Pro-Met-Leu-Lys, in the monkey hepatocyte cultures. METHODS: We evaluated albumin production, metabolizing abilities of ammonia, lidocaine, and diazepam of monkey hepato...

  20. HTS compatible assay for antioxidative agents using primary cultured hepatocytes.

    Science.gov (United States)

    Gaunitz, Frank; Heise, Kerstin

    2003-06-01

    We have used primary cultured rat hepatocytes to establish a system that is compatible with HTS for screening substance libraries for biologically active compounds. The hepatocytes were treated with t-BHP to induce oxidative stress, leading to the formation ROS. The involvement of ROS in oxidative stress and pathological alterations has been of major interest in recent years, and there is great demand to identify new compounds with antioxidant potential. In most HTS programs each compound is tested in duplicate, and may only be tested once. Because of this it is important to develop assays that can identify candidate compounds accurately and with high confidence. Using newly available cell-based assay systems, we have developed a system that can detect active compounds (hits) with a high degree of confidence. As an example of an agent that can be detected from a substance library, we analyzed the effect of fisetin as an antioxidative compound using this system. All measurements were performed using the newly developed and highly versatile Multilabel-Reader Mithras LB 940 (Berthold Technologies, Bad Wildbad, Germany). The data presented show that all Z' factors determined were highly reliable. Although the protocol is primarily designed to screen for substances with antioxidative potential, it can easily be adapted to screen for other biologically active substances.

  1. Study of Valproic Acid-Enhanced Hepatocyte Steatosis

    Directory of Open Access Journals (Sweden)

    Renin Chang

    2016-01-01

    Full Text Available Valproic acid (VPA is one of the most widely used antiepilepsy drugs. However, several side effects, including weight gain and fatty liver, have been reported in patients following VPA treatment. In this study, we explored the molecular mechanisms of VPA-induced hepatic steatosis using FL83B cell line-based in vitro model. Using fluorescent lipid staining technique, we found that VPA enhanced oleic acid- (OLA- induced lipid accumulation in a dose-dependent manner in hepatocytes; this may be due to upregulated lipid uptake, triacylglycerol (TAG synthesis, and lipid droplet formation. Real-time PCR results showed that, following VPA treatment, the expression levels of genes encoding cluster of differentiation 36 (Cd36, low-density lipoprotein receptor-related protein 1 (Lrp1, diacylglycerol acyltransferase 2 (Dgat2, and perilipin 2 (Plin2 were increased, that of carnitine palmitoyltransferase I a (Cpt1a was not affected, and those of acetyl-Co A carboxylase α (Acca and fatty acid synthase (Fasn were decreased. Furthermore, using immunofluorescence staining and flow cytometry analyses, we found that VPA also induced peroxisome proliferator-activated receptor γ (PPARγ nuclear translocation and increased levels of cell-surface CD36. Based on these results, we propose that VPA may enhance OLA-induced hepatocyte steatosis through the upregulation of PPARγ- and CD36-dependent lipid uptake, TAG synthesis, and lipid droplet formation.

  2. Rapid and sensitive measure of gluconeogenesis in isolated bovine hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Azain, M.J.; Kasser, T.R.; Atwell, C.A.; Baile, C.A.

    1986-03-05

    Available methods for determining glucose synthesis from radiolabelled precursors using ion exchange column chromatography limit the number of samples that can be processed. To facilitate this process, a rapid method for determining glucose synthesis from 3-carbon precursors was developed using suspensions of anion and cation exchange resins. Hepatocytes were prepared from calf liver by collagenase perfusion of the caudate lobe. Isolated cells were incubated with /sup 14/C-labelled lactate or propionate in the presence or absence of glucagen and/or palmitate. Glucose synthesis was determined by vortexing an aliquot of cell suspension with a 50% slurry of anion exchange resin (acetate form), followed by cation exchange resin. After centrifugation /sup 14/C-glucose was recovered in the supernatant and measured by scintillation counting. Using this method, more than 95% of unused labelled precursor was bound to the ion exchange resin and essentially 100% of /sup 14/C-glucose tracer was recovered in the supernatant. In hepatocyte suspensions, radioactivity recovered in the supernatants was confirmed to be glucose by pre-incubating aliquots of media with glucose oxidase prior to addition of ion exchange resins. The present system allows determination of hepatic gluconeogenesis, is sensitive to substrate and hormonal manipulations and has the capacity for processing several hundred samples per day.

  3. Discovering networks of perturbed biological processes in hepatocyte cultures.

    Directory of Open Access Journals (Sweden)

    Christopher D Lasher

    Full Text Available The liver plays a vital role in glucose homeostasis, the synthesis of bile acids and the detoxification of foreign substances. Liver culture systems are widely used to test adverse effects of drugs and environmental toxicants. The two most prevalent liver culture systems are hepatocyte monolayers (HMs and collagen sandwiches (CS. Despite their wide use, comprehensive transcriptional programs and interaction networks in these culture systems have not been systematically investigated. We integrated an existing temporal transcriptional dataset for HM and CS cultures of rat hepatocytes with a functional interaction network of rat genes. We aimed to exploit the functional interactions to identify statistically significant linkages between perturbed biological processes. To this end, we developed a novel approach to compute Contextual Biological Process Linkage Networks (CBPLNs. CBPLNs revealed numerous meaningful connections between different biological processes and gene sets, which we were successful in interpreting within the context of liver metabolism. Multiple phenomena captured by CBPLNs at the process level such as regulation, downstream effects, and feedback loops have well described counterparts at the gene and protein level. CBPLNs reveal high-level linkages between pathways and processes, making the identification of important biological trends more tractable than through interactions between individual genes and molecules alone. Our approach may provide a new route to explore, analyze, and understand cellular responses to internal and external cues within the context of the intricate networks of molecular interactions that control cellular behavior.

  4. Hepatocytes Polyploidization and Cell Cycle Control in Liver Physiopathology

    Directory of Open Access Journals (Sweden)

    Géraldine Gentric

    2012-01-01

    Full Text Available Most cells in mammalian tissues usually contain a diploid complement of chromosomes. However, numerous studies have demonstrated a major role of “diploid-polyploid conversion” during physiopathological processes in several tissues. In the liver parenchyma, progressive polyploidization of hepatocytes takes place during postnatal growth. Indeed, at the suckling-weaning transition, cytokinesis failure events induce the genesis of binucleated tetraploid liver cells. Insulin signalling, through regulation of the PI3K/Akt signalling pathway, is essential in the establishment of liver tetraploidization by controlling cytoskeletal organisation and consequently mitosis progression. Liver cell polyploidy is generally considered to indicate terminal differentiation and senescence, and both lead to a progressive loss of cell pluripotency associated to a markedly decreased replication capacity. Although adult liver is a quiescent organ, it retains a capacity to proliferate and to modulate its ploidy in response to various stimuli or aggression (partial hepatectomy, metabolic overload (i.e., high copper and iron hepatic levels, oxidative stress, toxic insult, and chronic hepatitis etc.. Here we review the mechanisms and functional consequences of hepatocytes polyploidization during normal and pathological liver growth.

  5. The mechanism of methyl mercury toxicity in isolated rat hepatocytes.

    Science.gov (United States)

    Ashour, H; Abdel-Rahman, M; Khodair, A

    1993-07-01

    Mercury is the major component of dental amalgam restorative material, which typically has 50% pure elemental mercury. It is also used in some skin creams, and in the manufacturing of plastic, drugs and fungicides. The present study was designed to investigate the toxicity of methyl mercury (MeHg+) on isolated rat hepatocytes using several toxicity parameters. The hepatocytes were isolated by a collagenase perfusion technique and were incubated with different concentrations of MeHg+ (0.1-100 ppm) for 2 h. Through the incubation period the viability was determined by Trypan blue exclusion. Reduced glutathione (GSH) content and its enzymes, glutathione peroxidase (GSH-PX) and glutathione reductase (GSH-RX) were measured. Leakage of enzymes such as aspartate transaminase (AST), and alanine transaminase (ALT) were determined. The cell viability was reduced significantly after 1 h incubation when 0.1 and 1 ppm MeHg+ were applied. The decrease in the cell viability was dose- and time-dependent. A depletion of GSH content was observed with 100 ppm MeHg+ after 30 min of incubation. A significant decrease in GSH-RX was observed with 100 ppm during 15 and 30 min of incubation, while 10 ppm of MeHg+ significantly increased ALT leakage after 60 min. However, there was a significant increase in AST leakage with 100 ppm only. The present investigation indicates that the toxic effect of MeHg+ is most likely cytosolic enzyme related.

  6. Measurement of Blood Coagulation Factor Synthesis in Cultures of Human Hepatocytes.

    Science.gov (United States)

    Heinz, Stefan; Braspenning, Joris

    2015-01-01

    An important function of the liver is the synthesis and secretion of blood coagulation factors. Within the liver, hepatocytes are involved in the synthesis of most blood coagulation factors, such as fibrinogen, prothrombin, factor V, VII, IX, X, XI, XII, as well as protein C and S, and antithrombin, whereas liver sinusoidal endothelial cells produce factor VIII and von Willebrand factor. Here, we describe methods for the detection and quantification of most blood coagulation factors in hepatocytes in vitro. Hepatocyte cultures indeed provide a valuable tool to study blood coagulation factors. In addition, the generation and expansion of hepatocytes or hepatocyte-like cells may be used in future for cell-based therapies of liver diseases, including blood coagulation factor deficiencies.

  7. In vivo N-acetyl cysteine reduce hepatocyte death by induced acetaminophen

    Science.gov (United States)

    Lin, Chih-Ju; Li, Feng-Chieh; Wang, Sheng-Shun; Lee, Hsuan-Shu; Dong, Chen-Yuan

    2011-07-01

    Acetaminophen (APAP) is the famous drug in global, and taking overdose Acetaminophen will intake hepatic cell injure. Desptie substantial progress in our understanding of the mechanism of hepatocellular injury during the last 40 years, many aspects of the pathophysiology are still unknown or controversial.1 In this study, mice are injected APAP overdose to damage hepatocyte. APAP deplete glutathione and ATP of cell, N-Acetyl Cysteine (NAC) plays an important role to protect hepatocytes be injury. N-Acetyl Cysteine provides mitochondrial to produce glutathione to release drug effect hepatocyte. By 6-carboxyfluorescein diacetate (6-CFDA) metabolism in vivo, glutathione keep depleting to observe the hepatocyte morphology in time. Without NAC, cell necrosis increase to plasma membrane damage to release 6-CFDA, that's rupture. After 6-CFDA injection, fluorescence will be retained in hepatocyte. For cell retain with NAC and without NAC are almost the same. With NAC, the number of cell rupture decreases about 75%.

  8. Depot-dependent effects of adipose tissue explants on co-cultured hepatocytes

    DEFF Research Database (Denmark)

    Du, Zhen-Yu; Ma, Tao; Lock, Erik-Jan;

    2011-01-01

    We have developed an in vitro hepatocyte-adipose tissue explant (ATE) co-culture model enabling examination of the effect of visceral and subcutaneous adipose tissues on primary rat hepatocytes. Initial analyses of inflammatory marker genes were performed in fractionated epididymal or inguinal...... levels of IL-6, TNF-a and PGE(2) in the media from inguinal ATEs co-cultured with primary rat hepatocytes were higher than that in the media from epididymal ATEs co-cultured with hepatocytes, although the significant difference was only seen in PGE(2). Lipolysis, measured as glycerol release, was similar...... in the ATEs isolated from inguinal and epididymal adipose tissues when cultured alone, but the glycerol release was higher in the ATEs isolated from epididymal than from inguinal adipose tissue when co-cultured with hepatocytes. Compared to epididymal ATEs, the ATEs from inguinal adipose tissue elicited...

  9. Differentiation of human embryonic stem cells along a hepatocyte lineage and its application in liver regeneration

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Hepatocyte transplantation and bioartificial liver(BAL)as alternatives to liver transplantation offer the possibility of effective treatment for many inherited and acquired hepatic disorders.Unfortunately,the limited availability of donated livers and the variability of their derived hepatocytes make it difficult to obtain enough viable human hepatocytes for the hepatocyte-based therapies.Embryonic stem cells (ESCs),which could be isolated directly from the blastocyst inner cell mass,have permanent self-renewal capability and developmental pluripotency and therefore might be an ideal cell source in the treatment of hepatic discords.However,differentiation of hESCS into hepatocytes with significant numbers remains a challenge.This review updates our current understanding of differentiation of ESCs into hepatic lineage cells,their future therapeutic uses and problems in liver regeneration.

  10. Lineage tracing reveals conversion of liver sinusoidal endothelial cells into hepatocytes.

    Science.gov (United States)

    Tan, Zhaoli; Chen, Keyan; Shao, Yong; Gao, Lihua; Wang, Yan; Xu, Jianming; Jin, Yang; Hu, Xianwen; Wang, Youliang

    2016-09-01

    Although liver sinusoidal endothelial cells (LSECs) have long been known to contribute to liver regeneration following injury, the exact role of these cells in liver regeneration remains poorly understood. In this work, we performed lineage tracing of LSECs in mice carrying Tie2-Cre or VE-cadherin-Cre constructs to facilitate fate-mapping of LSECs in liver regeneration. Some YFP-positive LSECs were observed to convert into hepatocytes following a two-thirds partial hepatectomy (PH). Furthermore, human umbilical vein endothelial cells (HUVECs) could be triggered to convert into cells that closely resembled hepatocytes when cultured with serum from mice that underwent an extended PH. These findings suggest that mature non-hepatocyte LSECs play an essential role in mammalian liver regeneration by converting to hepatocytes. The conversion of LSECs to hepatocyte-like (iHep) cells may provide a new approach to tissue engineering.

  11. Macrophage secretory products induce an inflammatory phenotype in hepatocytes

    Institute of Scientific and Technical Information of China (English)

    Michelle Melino; Gethin P Thomas; Andrew D Clouston; Julie R Jonsson; Elizabeth E Powell; Victoria L Gadd; Gene V Walker; Richard Skoien; Helen D Barrie; Dinesh Jothimani; Leigh Horsfall; Alun Jones; Matthew J Sweet

    2012-01-01

    AIM:To investigate the influence of macrophages on hepatocyte phenotype and function.METHODS:Macrophages were differentiated from THP-1 monocytes via phorbol myristate acetate stimulation and the effects of monocyte or macrophageconditioned medium on HepG2 mRNA and protein expression determined.The in vivo relevance of these findings was confirmed using liver biopsies from 147patients with hepatitis C virus (HCV) infection.RESULTS:Conditioned media from macrophages,but not monocytes,induced a transient morphological change in hepatocytes associated with upregulation of vimentin (7.8 ± 2.5-fold,P =0.045) and transforming growth factor (TGF)-β1 (2.6 ± 0.2-fold,P < 0.001) and downregulation of epithelial cadherin (1.7 ± 0.02-fold,P =0.017) mRNA expression.Microarray analysis revealed significant upregulation of lipocalin-2 (17-fold,P < 0.001) and pathways associated with inflammation,and substantial downregulation of pathways related to hepatocyte function.In patients with chronic HCV,realtime polymerase chain reaction and immunohistochemistry confirmed an increase in lipocalin-2 mRNA (F0 1.0± 0.3,F1 2.2 ± 0.2,F2 3.0 ± 9.3,F3/4 4.0 ± 0.8,P =0.003) and protein expression (F1 1.0 ± 0.5,F2 1.3 ±0.4,F3/4 3.6 ± 0.4,P =0.014) with increasing liver injury.High performance liquid chromatography-tandem mass spectrometry analysis identified elevated levels of matrix metalloproteinase (MMP)-9 in macrophageconditioned medium,and a chemical inhibitor of MMP-9attenuated the change in morphology and mRNA expression of TGF-β1 (2.9 ± 0.2 vs 1.04 ± 0.1,P < 0.001)in macrophage-conditioned media treated HepG2 cells.In patients with chronic HCV infection,hepatic mRNA expression of CD163 (F0 1.0 ± 0.2,F1/2 2.8 ± 0.3,F3/4 5.3 ± 1.0,P =0.001) and MMP-9 (F0 1.0 ± 0.4,F1/2 2.8 ± 0.3,F3/4 4.1 ± 0.8,P =0.011) was significantly associated with increasing stage of fibrosis.CONCLUSION:Secreted macrophage products alter the phenotype and function of hepatocytes

  12. Influence of 48 hours of cold storage in University of Wisconsin organ preservation solution on metabolic capacity of rat hepatocytes

    NARCIS (Netherlands)

    Olinga, Peter; Slooff, M.JH; Meijer, D.K F; Groothuis, Geny; Merema, M.T.

    1997-01-01

    Background/Aims: Suspensions of isolated hepatocytes are a valuable tool to study liver functions, For optimal use of the isolated hepatocytes, methods are needed to preserve the hepatocytes while maintaining their viability, metabolic and transport functions, Until now little has been known about t

  13. Omeprazole and lansoprazole enantiomers induce CYP3A4 in human hepatocytes and cell lines via glucocorticoid receptor and pregnane X receptor axis.

    Science.gov (United States)

    Novotna, Aneta; Dvorak, Zdenek

    2014-01-01

    Benzimidazole drugs lansoprazole and omeprazole are used for treatment of various gastrointestinal pathologies. Both compounds cause drug-drug interactions because they activate aryl hydrocarbon receptor and induce CYP1A genes. In the current paper, we examined the effects of lansoprazole and omeprazole enantiomers on the expression of key drug-metabolizing enzyme CYP3A4 in human hepatocytes and human cancer cell lines. Lansoprazole enantiomers, but not omeprazole, were equipotent inducers of CYP3A4 mRNA in HepG2 cells. All forms (S-, R-, rac-) of lansoprazole and omeprazole induced CYP3A4 mRNA and protein in human hepatocytes. The quantitative profiles of CYP3A4 induction by individual forms of lansoprazole and omeprazole exerted enantiospecific patterns. Lansoprazole dose-dependently activated pregnane X receptor PXR in gene reporter assays, and slightly modulated rifampicin-inducible PXR activity, with similar potency for each enantiomer. Omeprazole dose-dependently activated PXR and inhibited rifampicin-inducible PXR activity. The effects of S-omeprazole were much stronger as compared to those of R-omeprazole. All forms of lansoprazole, but not omeprazole, slightly activated glucocorticoid receptor and augmented dexamethasone-induced GR transcriptional activity. Omeprazole and lansoprazole influenced basal and ligand inducible expression of tyrosine aminotransferase, a GR-target gene, in HepG2 cells and human hepatocytes. Overall, we demonstrate here that omeprazole and lansoprazole enantiomers induce CYP3A4 in HepG2 cells and human hepatocytes. The induction comprises differential interactions of omeprazole and lansoprazole with transcriptional regulators PXR and GR, and some of the effects were enantiospecific. The data presented here might be of toxicological and clinical importance, since the effects occurred in therapeutically relevant concentrations.

  14. Taurolithocholate impairs bile canalicular motility and canalicular bile secretion in isolated rat hepatocyte couplets

    Institute of Scientific and Technical Information of China (English)

    Norihito Watanabe; Tatehiro Kagawa; Sei-ichiro Kojima; Shinji Takashimizu; Naruhiko Nagata; Yasuhiro Nishizaki; Tetsuya Mine

    2006-01-01

    AIM: To investigate the effects of taurolithocholate (TLC)on the canalicular motility in isolated rat hepatocyte couplets (IRHC).METHODS: TLC was added to IRHC at concentrations of 10 and 50 μmol/L, respectively. In each group, five time-lapse movies containing 3 representative bile canaliculi were taken under phase-contrast microscopy for 12 h. The number of bile canalicular contractions and the intervals between consecutive canalicular contractions were calculated. Furthermore, the effects of TLC on IRHC were examined by transmission electron microscopy.RESULTS: The bile canalicular contractions were spontaneous and forceful in the controls. Active vesicular movement was observed in the pericanalicular region. Immediately after the addition of TLC, the bile canaliculi were deformed, and canalicular bile was incorporated into the vacuoles. The canaliculi were gradually dilated, and canalicular contractions were markedly inhibited by TLC. The vesicular movements became extremely slow in the pericanalicular region. The number of canalicular contractions significantly decreased in the TLC-treated groups, as compared with that in the controls. The time intervals were prolonged, as the TLC dosage increased,indicating that bile secretion into the canaliculi was impaired with TLC. Transmission electron microscopy revealed the lamellar transformation of the canalicular membranes in IRHC treated with TLC.CONCLUSION: TLC impairs both the bile canalicular contractions and the canalicular bile secretion, possibly by acting directly on the canalicular membranes in TLCinduced cholestasis.

  15. Lupeol protects against acetaminophen-induced oxidative stress and cell death in rat primary hepatocytes.

    Science.gov (United States)

    Kumari, Archana; Kakkar, Poonam

    2012-05-01

    Drug induced hepatotoxicity is a major problem where phytochemicals hold promise for its abrogation. This study was carried out to explore cytoprotective potential of lupeol, a triterpene, against acetaminophen (AAP)-induced toxicity in rat hepatocytes. AAP exposure significantly (p<0.05) reduced cell viability, disturbed Bcl-2 family pro/anti-apoptotic protein balance, increased ROS production and altered redox homeostasis. It also induced mitochondria-mediated hepatocellular injury by significant mitochondrial depolarization, caspase-9/3 activation and subsequent DNA fragmentation. Our results suggest that lupeol pre-treatment effectively restored antioxidant enzyme levels, decreased lipid peroxidation, inhibited ROS generation and depolarization of mitochondria. Lupeol also attenuated mitochondria-mediated signaling pathway and DNA damage as evident from TUNEL assay and cell cycle studies leading to prevention of cytotoxicity. This study confirms the efficacy of lupeol, a food derived antioxidant, in abrogating ROS generation, maintaining redox balance and providing significant protection against mitochondria-mediated cell death during AAP-induced toxicity.

  16. Modulating Innate Immunity Improves Hepatitis C Virus Infection and Replication in Stem Cell-Derived Hepatocytes

    Directory of Open Access Journals (Sweden)

    Xiaoling Zhou

    2014-07-01

    Full Text Available In this study, human embryonic stem cell-derived hepatocytes (hESC-Heps were investigated for their ability to support hepatitis C virus (HCV infection and replication. hESC-Heps were capable of supporting the full viral life cycle, including the release of infectious virions. Although supportive, hESC-Hep viral infection levels were not as great as those observed in Huh7 cells. We reasoned that innate immune responses in hESC-Heps may lead to the low level of infection and replication. Upon further investigation, we identified a strong type III interferon response in hESC-Heps that was triggered by HCV. Interestingly, specific inhibition of the JAK/STAT signaling pathway led to an increase in HCV infection and replication in hESC-Heps. Of note, the interferon response was not evident in Huh7 cells. In summary, we have established a robust cell-based system that allows the in-depth study of virus-host interactions in vitro.

  17. Hepatocyte growth factor, a determinant of airspace homeostasis in the murine lung.

    Directory of Open Access Journals (Sweden)

    Carla Calvi

    Full Text Available The alveolar compartment, the fundamental gas exchange unit in the lung, is critical for tissue oxygenation and viability. We explored hepatocyte growth factor (HGF, a pleiotrophic cytokine that promotes epithelial proliferation, morphogenesis, migration, and resistance to apoptosis, as a candidate mediator of alveolar formation and regeneration. Mice deficient in the expression of the HGF receptor Met in lung epithelial cells demonstrated impaired airspace formation marked by a reduction in alveolar epithelial cell abundance and survival, truncation of the pulmonary vascular bed, and enhanced oxidative stress. Administration of recombinant HGF to tight-skin mice, an established genetic emphysema model, attenuated airspace enlargement and reduced oxidative stress. Repair in the TSK/+ mouse was punctuated by enhanced akt and stat3 activation. HGF treatment of an alveolar epithelial cell line not only induced proliferation and scattering of the cells but also conferred protection against staurosporine-induced apoptosis, properties critical for alveolar septation. HGF promoted cell survival was attenuated by akt inhibition. Primary alveolar epithelial cells treated with HGF showed improved survival and enhanced antioxidant production. In conclusion, using both loss-of-function and gain-of-function maneuvers, we show that HGF signaling is necessary for alveolar homeostasis in the developing lung and that augmentation of HGF signaling can improve airspace morphology in murine emphysema. Our studies converge on prosurvival signaling and antioxidant protection as critical pathways in HGF-mediated airspace maintenance or repair. These findings support the exploration of HGF signaling enhancement for diseases of the airspace.

  18. ADAR1 Prevents Liver Injury from Inflammation and Suppresses Interferon Production in Hepatocytes.

    Science.gov (United States)

    Wang, Guoliang; Wang, Hui; Singh, Sucha; Zhou, Pei; Yang, Shengyong; Wang, Yujuan; Zhu, Zhaowei; Zhang, Jinxiang; Chen, Alex; Billiar, Timothy; Monga, Satdarshan P; Wang, Qingde

    2015-12-01

    Adenosine deaminase acting on RNA 1 (ADAR1) is an essential protein for embryonic liver development. ADAR1 loss is embryonically lethal because of severe liver damage. Although ADAR1 is required in adult livers to prevent liver cell death, as demonstrated by liver-specific conditional knockout (Alb-ADAR1(KO)) mice, the mechanism remains elusive. We systematically analyzed Alb-ADAR1(KO) mice for liver damage. Differentiation genes and inflammatory pathways were examined in hepatic tissues from Alb-ADAR1(KO) and littermate controls. Inducible ADAR1 KO mice were used to validate regulatory effects of ADAR1 on inflammatory cytokines. We found that Alb-ADAR1(KO) mice showed dramatic growth retardation and high mortality because of severe structural and functional damage to the liver, which showed overwhelming inflammation, cell death, fibrosis, fatty change, and compensatory regeneration. Simultaneously, Alb-ADAR1(KO) showed altered expression of key differentiation genes and significantly higher levels of hepatic inflammatory cytokines, especially type I interferons, which was also verified by inducible ADAR1 knockdown in primary hepatocyte cultures. We conclude that ADAR1 is an essential molecule for maintaining adult liver homeostasis and, in turn, morphological and functional integrity. It inhibits the production of type I interferons and other inflammatory cytokines. Our findings may provide novel insight in the pathogenesis of liver diseases caused by excessive inflammatory responses, including autoimmune hepatitis.

  19. Effects of the Amino Acid Constituents of Microcystin Variants on Cytotoxicity to Primary Cultured Rat Hepatocytes

    Directory of Open Access Journals (Sweden)

    Kumiko Shimizu

    2013-12-01

    Full Text Available Microcystins, which are cyclic heptapeptides produced by some cyanobacterial species from algal blooms, strongly inhibit serine/threonine protein phosphatase and are known as hepatotoxins. Microcystins have many structural variations, yet insufficient information is available on the differences in the cytotoxic potentials among the structural variants. In this study, the cytotoxicities of 16 microcystin variants at concentrations of 0.03–10 μg/mL to primary cultured rat hepatocytes were determined by measuring cellular ATP content, and subsequently determined by their 50% inhibitory concentration (IC50. Differences in the amino acid constituents were associated with differences in cytotoxic potential. [d-Asp3, Z-Dhb7] microcystin-LR exhibited the strongest cytotoxicity at IC50 of 0.053 μg/mL among the microcystin variants tested. Furthermore, [d-Asp3, Z-Dhb7] microcystin-HtyR was also highly cytotoxic. These results suggest that both d-Asp and Z-Dhb residues are important in determining the cytotoxic potential of microcystin variants.

  20. 丹酚酸A诱导HepG2细胞凋亡及抑制c-Met表达%Salvianolic Acid A Induces Apoptosis and Inhibits the C-Met Expression in Hepatocellular Carcinoma HepG2 Cell Line

    Institute of Scientific and Technical Information of China (English)

    唐志华; 丁洁卫; 肖幸丰

    2014-01-01

    目的 通过研究丹酚酸A(salvianol acid A,SalA)对肝癌HepG2细胞株c-Met蛋白表达的影响,探讨SalA抑制肝癌细胞增殖,诱导细胞凋亡的可能作用机制.方法 以肝癌HepG2细胞株为研究对象,采用MTT法及流式细胞术检测SalA作用后细胞存活、增殖及凋亡情况;同时运用Western blot法及PCR法检测HepG2细胞c-Met及其下游信号通路中关键蛋白和基因表达的改变.结果 肝癌HepG2细胞经SalA处理后,其细胞增殖显著抑制,细胞凋亡比例亦升高,且呈浓度依赖性;同时HepG2细胞中c-Met及其下游信号分子AKT的磷酸化水平显著下调,凋亡相关蛋白Bax、caspase-3和caspase-9的表达亦明显上调.结论 SalA能有效抑制肝癌HepG2细胞的增殖并诱导细胞凋亡,其作用机制可能与其抑制HepG2细胞中c-Met蛋白及其下游信号通路中AKT蛋白的磷酸化水平有关.

  1. Viscosity regulates apolipoprotein A-1 gene expression in experimental models of secondary hyperlipidemia and in cultured hepatocytes.

    Science.gov (United States)

    Nuño, P; Hernández, A; Mendoza-Figueroa, T; Panduro, A

    1997-02-18

    This study analyzes the relationship of plasmatic colloid osmotic pressure (PCO) and viscosity with the different hyperlipidemic stages observed in rats with acute liver damage induced by carbon tetrachloride (CCl4) and in rats with nephrotic syndrome induced by puromycin amino nucleoside (PAN). In both animal models viscosity increases were associated with the induction of the hyperlipidemic stage characterized by an increase of high density lipoproteins (HDL) and steady-state levels (SSL) of apo A-1 mRNA. In both animal models PCO decreased at early stages of the disease when hyperlipidemia was characterized principally by an increase of total cholesterol and triacylglycerols, but was not associated with the induction of HDL and apo A-1 mRNA. To confirm the in vivo findings, we studied the effect of viscosity on apo A-1 gene expression in an in vitro model using cultured hepatocytes. When medium viscosity was maintained below physiological values, an induction of the SSL of apo A-1 mRNA was observed. By contrast, when medium viscosity was raised to values similar or higher than the physiological range, the SSL of apo A-1 mRNA decreased steadily and after 24 h incubation an almost total inhibition was observed. These results suggest that in both experimental animal models of secondary hyperlipidemia, small viscosity changes below the physiological range, most probably in the interstitial fluid, can induce apo A-1 gene expression at the mRNA level, and that when viscosity reaches physiological values, apo A-1 gene expression is inhibited. Both effects were shown in cultured hepatocytes.

  2. Changes in alpha 2- and beta-adrenoceptors in hepatocytes from rats during treatment with 3'-methyl-4-dimethylaminoazobenzene.

    Science.gov (United States)

    Sanae, F; Kohei, K; Nomura, M; Miyamoto, K

    1992-05-01

    A 3'-methyl-4-dimethylaminoazobenzene (3'-MeDAB) containing diet was given to 6 weeks old female Donryu rats, and the number of adrenoceptors and the response of adenylate cyclase in the hepatocytes were measured. The treatment with 3'-MeDAB led to rapid increases in [125I]iodocyanopindolol ([125I]ICYP)- and [3H]clonidine-binding sites to hepatic membranes without significant changes in the Kd values. The number or beta-adrenoceptors defined by [125I]ICYP binding sites was increased with a biphagic mode. The [3H]clonidine binding reached a peak 2 weeks after the start of the carcinogen diet and then began a slow descent. The alpha 2-adrenoceptor was defined by [3H]clonidine binding being selectively inhibited by an alpha 2-antagonist, yohimbine, but not by an alpha 1-antagonist, prazosin, or a beta-antagonist propranolol. Catecholamine responsiveness to adenylate cyclase in hepatocytes also increased during treatment with 3'-MeDAB. However, the efficacy of norepinephrine (NE) in activating cyclase was lower than that of isoproterenol (IPN) during 4 to 8 weeks of the carcinogen diet. The difference between the efficacies of IPN and NE resulted from inhibiting adenylate cyclase through alpha 2-adrenoceptors by NE. Therefore, we noticed that the increasing pattern of the number of beta-adrenoceptors did not always parallel IPN-stimulated adenylate cyclase activity and that the increase in the number of alpha 2-adrenoceptors preceded the difference between the efficacies of IPN and NE in activating adenylate cyclase.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. Hepatocyte nuclear factor 4α suppresses the aggravation of colon carcinoma.

    Science.gov (United States)

    Yao, Hou Shan; Wang, Juan; Zhang, Xiao Ping; Wang, Liang Zhe; Wang, Yi; Li, Xin Xing; Jin, Kai Zhou; Hu, Zhi Qian; Wang, Wei Jun

    2016-05-01

    Hepatocyte nuclear factor 4-α (HNF4α), a nuclear receptor, is expressed at lower levels in colon carcinoma tissues than in adjacent normal tissues. However, the relation between HNF4α and colon cancer progression and the underlying molecular mechanisms remain unclear. Here, we investigated the role of HNF4α in the progression of colon carcinoma. We showed that HNF4α mRNA and protein were downregulated in colon carcinoma specimens. HNF4α expression was related to pT classification (P colon carcinoma patients. Patients with low or negative HNF4α expression had worse 3-year progression-free survival (PFS, P = 0.006) and overall survival (OS, P = 0.005) than patients with high HNF4α expression. Low HNF4α expression was an independent prognostic factor for 3-year PFS (hazard ratio 2.94; 95% confidence interval 1.047-8.250; P = 0.041). Ectopic expression of HNF4α inhibited colon carcinoma cell (HT29, LoVo, and SW480) proliferation, migration, and invasion, induced G2/M phase arrest and promoted apoptosis. Ectopic expression of HNF4α upregulated E-cadherin and downregulated vimentin in vitro, and suppressed SW480 xenograft tumor growth and liver metastasis in vivo. Furthermore, HNF4α overexpression downregulated the expression of snail, slug and twist. HNF4α inhibited EMT through its effect on the Wnt/β-catenin signaling pathway, and HNF4α downregulation may be mediated by promoter methylation in cancer tissues. Our results suggest that downregulation of HNF4α plays a critical role in the aggravation of colon carcinoma possibly by promoting EMT via the Wnt/β-catenin signaling pathway and by affecting apoptosis and cell cycle progression.

  4. KAI1 inhibits HGF-induced invasion of pancreatic cancer by sphingosine kinase activity

    Institute of Scientific and Technical Information of China (English)

    Xu Liu; Xiao-Zhong Guo; Wei-Wei Zhang; Zhuo-Zhuang Lu; Qun-Wei Zhang; Hai-Feng Duan; d Li-Sheng Wang

    2011-01-01

    BACKGROUND: KAI1/CD82 has been reported to attenuate the process of metastases in a variety of tumors; however, its mechanism of action in invasion has not been fully elucidated. The present study aimed to investigate the importance of KAI1 in invasion and its correlation with activation of sphingosine kinase (SPK) in human pancreatic cancer PANC1 and Miapaca-2 cell lines. METHODS: The expression of KAI1 in PANC1 and Miapaca-2 cells,whichwasmediatedbyrecombinantadenovirus(Ad-KAI1), was assessed by a flow cytometer and Western blotting. After successful infection was established, in vitro growth curve and invasive ability in Boyden Chamber assay were studied. The presence of KAI1 correlating with c-Met and SPK was detected by co-immunoprecipitationand[γ-32P]ATPincorporation. RESULTS: KAI1 genes had no significant effects on the curve representing cell growth. After infection with the KAI1 gene, decreased invasive ability in the Boyden Chamber assay was observed in PANC1 and Miapaca-2 cells that were induced by hepatocyte growth factor. Over-expression of KAI1 in the cells led to the deactivation of SPK and a decreased level of intracellular sphingosine-1-phosphate. No correlation was observed between c-Met and KAI1 during co-immunoprecipitation. CONCLUSION: The results of this study for the first time demonstrated a regulatory role for KAI1 in SPK activation, which leads to decreased invasive ability in disease progression of human pancreatic cancer.

  5. In vitro induction of human embryonic stem cells into hepatocyte-like cells

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Human embryonic stem cells (hES cells) are pluripotent and provide a unique, unlimited resource for human hepatocytes, which can serve as a novel cell source for cell transplantation and bioartificial liver (BAL). Here, we have developed a procedure by which hES cells can differentiate into hepatocyte-like cells. After being cultured in suspension in bacteriological petri dishes for 7 d, hES cells developed into cystic embryoid bodies (EBs). The EBs were then cultured in conditional medium containing dexamethasone and insulin in collagen type I-coated tissue culture dishes for two weeks. The hES cell-derived hepatocyte-like cells (HLCs) displayed some morphologic characteristics of hepatocytes. Reverse-transcription polymerase chain reaction (RT-PCR) and immunofluorescence cell staining proved that the induced HLCs expressed several hepatocyte specific genes including AFP, ALB, CYP1B1 and cytokeratins CK18 and CK19. Furthermore, the induced cells executed a range of hepatocyte functions, such as ICG uptake/excretion, glycogen deposits, albumin production and ammonium metabolism. Taken together, our results show that HLCs exhibit similar morphologic, phenotypic, and functional characteristics to hepatocytes.

  6. Circadian rhythms of Per2::Luc in individual primary mouse hepatocytes and cultures.

    Directory of Open Access Journals (Sweden)

    Casey J Guenthner

    Full Text Available BACKGROUND: Hepatocytes, the parenchymal cells of the liver, express core clock genes, such as Period2 and Cryptochrome2, which are involved in the transcriptional/translational feedback loop of the circadian clock. Whether or not the liver is capable of sustaining rhythms independent of a central pacemaker is controversial. Whether and how circadian information may be shared among cells in the liver in order to sustain oscillations is currently unknown. RESULTS: In this study we isolated primary hepatocytes from transgenic Per2(Luc mice and used bioluminescence as a read-out of the state of the circadian clock. Hepatocytes cultured in a collagen gel sandwich configuration exhibited persistent circadian rhythms for several weeks. The amplitude of the rhythms damped, but medium changes consistently reset the phase and amplitude of the cultures. Cry2(-/- Per2(Luc cells oscillated robustly and expressed a longer period. Co-culturing with wildtype cells did not significantly shorten the period, indicating that coupling among hepatocytes is insufficient to synchronize cells with significantly differing periods. However, spatial patterns revealed by cellular imaging of wildtype cultures provided evidence of weak local coupling among the hepatocytes. CONCLUSIONS: Our results with primary hepatocyte cultures demonstrate that cultured hepatocytes are weakly coupled. While this coupling is not sufficient to sustain global synchrony, it does increase local synchrony, which may stabilize the circadian rhythms of peripheral oscillators, such as the liver, against noise in the entraining signals.

  7. Asialoglycoprotein Receptor-Mediated Gene Delivery to Hepatocytes Using Galactosylated Polymers.

    Science.gov (United States)

    Thapa, Bindu; Kumar, Piyush; Zeng, Hongbo; Narain, Ravin

    2015-09-14

    Highly efficient, specific, and nontoxic gene delivery vector is required for gene therapy to the liver. Hepatocytes exclusively express asialoglycoprotein receptor (ASGPR), which can recognize and bind to galactose or N-acetylgalactosamine. Galactosylated polymers are therefore explored for targeted gene delivery to the liver. A library of safe and stable galactose-based glycopolymers that can specifically deliver genes to hepatocytes were synthesized having different architectures, compositions, and molecular weights via the reversible addition-fragmentation chain transfer process. The physical and chemical properties of these polymers have a great impact on gene delivery efficacy into hepatocytes, as such block copolymers are found to form more stable complexes with plasmid and have high gene delivery efficiency into ASGPR expressing hepatocytes. Transfection efficiency and uptake of polyplexes with these polymers decreased significantly by preincubation of hepatocytes with free asialofetuin or by adding free asialofetuin together with polyplexes into hepatocytes. The results confirmed that polyplexes with these polymers were taken up specifically by hepatocytes via ASGPR-mediated endocytosis. The results from transfection efficiency and uptake of these polymers in cells without ASGPR, such as SK Hep1 and HeLa cells, further support this mechanism. Since in vitro cytotoxicity assays prove these glycopolymers to be nontoxic, they may be useful for delivery of clinically important genes specifically to the liver.

  8. Nrf2 is involved in maintaining hepatocyte identity during liver regeneration.

    Directory of Open Access Journals (Sweden)

    Yuhong Zou

    Full Text Available Nrf2, a central regulator of the cellular defense against oxidative stress and inflammation, participates in modulating hepatocyte proliferation during liver regeneration. It is not clear, however, whether Nrf2 regulates hepatocyte growth, an important cellular mechanism to regain the lost liver mass after partial hepatectomy (PH. To determine this, various analyses were performed in wild-type and Nrf2-null mice following PH. We found that, at 60 h post-PH, the vast majority of hepatocytes lacking Nrf2 reduced their sizes, activated hepatic progenitor markers (CD133, TWEAK receptor, and trefoil factor family 3, depleted HNF4α protein, and downregulated the expression of a group of genes critical for their functions. Thus, the identity of hepatocytes deficient in Nrf2 was transiently but massively impaired in response to liver mass loss. This event was associated with the coupling of protein depletion of hepatic HNF4α, a master regulator of hepatocyte differentiation, and concomitant inactivation of hepatic Akt1 and p70S6K, critical hepatocyte growth signaling molecules. We conclude that Nrf2 participates in maintaining newly regenerated hepatocytes in a fully differentiated state by ensuring proper regulation of HNF4α, Akt1, and p70S6K during liver regeneration.

  9. Mycelial culture of Phellinus linteus protects primary cultured rat hepatocytes against hepatotoxins.

    Science.gov (United States)

    Kim, S H; Lee, H S; Lee, S; Cho, J; Ze, K; Sung, J; Kim, Y C

    2004-12-01

    Hepatoprotective activity of Phellinus linteus was studied using H(2)O(2)- or galactosamine-injured primary cultures of rat hepatocytes as screening systems. The methanolic extract of the mycelial culture of Phellinus linteus significantly protected against hepatotoxins-induced toxicity in primary cultured rat hepatocytes as seen from the decreased level of glutamic pyruvic transaminase released from the injured hepatocytes. The methanolic extract of the mycelial culture of Phellinus linteus was subsequently fractionated with n-hexane, ethyl acetate, n-butanol and water. Among these fractions, 100 microg/mL of the ethyl acetate fraction was the most active one. The relative protections were 68.9 +/- 5.3% in H(2)O(2)-injured hepatocytes and 46.8 +/- 3.9% in galactosamine-injured hepatocytes, respectively. The ethyl acetate fraction appeared to maintain the glutathione level which was decreased by the treatment of H(2)O(2) or galactosamine and restored the level of RNA synthesis more than two times compared to galactosamine-injured hepatocytes. These results suggest that the ethyl acetate fraction of the mycelial culture of Phellinus linteus protects hepatocytes from H(2)O(2)- or galactosamine-induced injury by maintaining hepatic glutathione level and RNA synthesis as well.

  10. Auxiliary liver organ formation by implantation of spleen-encapsulated hepatocytes.

    Science.gov (United States)

    Nishio, Reiji; Nakayama, Miyuki; Ikekita, Masahiko; Watanabe, Yoshifumi

    2006-09-01

    Hepatocyte transplantation is an attractive alternative to orthotopic liver transplantation. However, its application has been limited because of its short-term success only. Here we report a new approach to hepatocyte transplantation resulting in the generation of an auxiliary liver in vivo. Isolated primary hepatocytes were encapsulated in isolated spleens and then transplanted by attaching the spleens to the livers of recipient animals (mice or rats) using biodegradable adhesive. A vascular network was rapidly established, and protein molecules circulated freely between the transplanted spleen and the liver, to which they adhered. In contrast, the spleen, which did not adhere to the liver or adhered elsewhere (adipose tissue or peritoneum), did not become vascularized but shrank and died. Encapsulation of hepatocytes in an isolated spleen enhanced their survival significantly, and co-encapsulation of Engelbreth- Holm-Swarm gel together with the hepatocytes further enhanced it. The encapsulated hepatocytes expressed liver-specific differentiation genes for more than 3 weeks. Plasma albumin concentrations in Nagase analbuminemic rats began to increase 3 days after transplantation. The transplanted hepatic cells migrated into the liver parenchyma, whereas the spleen was absorbed. Thus, we have developed a novel, simple approach for the rapid and efficient formation of functional auxiliary liver using a modified hepatocyte transplantation method.

  11. Restoration of cell polarity and bile excretion function of hepatocytes in sandwich-culture

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xian-jie; WANG Ying; SUN Jia-bang; SONG Mao-min; QIAO Xin

    2007-01-01

    Objective:To investigate the nature of the restoration of cell polarity and bile excretion function in Sandwich-cultured hepatocytes.Methods:Freshly isolated hepatocytes from male Sprague-Dawley rats were cultured in a double layer collagen gel Sandwich configuration.Morphological changes were observed under a inverted microscope.The domain specific membrane associated protein DPP Ⅳ was tested by immunofluorescenee,and the bile excretion function was determined by using fluorescein diacetate.Hepatocytes cultured on a single layer of collagen gel were taken as control.Results:Adult rat hepatocytes cultured in a double layer collagen gel sandwich configuration regained its morphological and functional polarity and maintained polygonal morphology for at least 4 weeks.Immunofluorescence studies USing antibodies against DPP Ⅳ showed polarity restoration as early as 48 h.After cultured in the double layer collagen gel Sandwich configuration for 96 h the hepatocytes began to excrete bile;while hepatocytes cultured on a single layer collagen gel had no bile excretion.Conclusion:Hepatocytes cultured in a double layer collagen gel Sandwich configuration are able to regain their morphological and functional polarity givan certain conditions.Hepaotcyte culture is a useful tool for the study of polarity restoration.

  12. 3D hepatic cultures simultaneously maintain primary hepatocyte and liver sinusoidal endothelial cell phenotypes.

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    Yeonhee Kim

    Full Text Available Developing in vitro engineered hepatic tissues that exhibit stable phenotype is a major challenge in the field of hepatic tissue engineering. However, the rapid dedifferentiation of hepatic parenchymal (hepatocytes and non-parenchymal (liver sinusoidal endothelial, LSEC cell types when removed from their natural environment in vivo remains a major obstacle. The primary goal of this study was to demonstrate that hepatic cells cultured in layered architectures could preserve or potentially enhance liver-specific behavior of both cell types. Primary rat hepatocytes and rat LSECs (rLSECs were cultured in a layered three-dimensional (3D configuration. The cell layers were separated by a chitosan-hyaluronic acid polyelectrolyte multilayer (PEM, which served to mimic the Space of Disse. Hepatocytes and rLSECs exhibited several key phenotypic characteristics over a twelve day culture period. Immunostaining for the sinusoidal endothelial 1 antibody (SE-1 demonstrated that rLSECs cultured in the 3D hepatic model maintained this unique feature over twelve days. In contrast, rLSECs cultured in monolayers lost their phenotype within three days. The unique stratified structure of the 3D culture resulted in enhanced heterotypic cell-cell interactions, which led to improvements in hepatocyte functions. Albumin production increased three to six fold in the rLSEC-PEM-Hepatocyte cultures. Only rLSEC-PEM-Hepatocyte cultures exhibited increasing CYP1A1/2 and CYP3A activity. Well-defined bile canaliculi were observed only in the rLSEC-PEM-Hepatocyte cultures. Together, these data suggest that rLSEC-PEM-Hepatocyte cultures are highly suitable models to monitor the transformation of toxins in the liver and their transport out of this organ. In summary, these results indicate that the layered rLSEC-PEM-hepatocyte model, which recapitulates key features of hepatic sinusoids, is a potentially powerful medium for obtaining comprehensive knowledge on liver metabolism

  13. Development of mouse hepatocyte lines permissive for hepatitis C virus (HCV.

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    Hussein Hassan Aly

    Full Text Available The lack of a suitable small animal model for the analysis of hepatitis C virus (HCV infection has hampered elucidation of the HCV life cycle and the development of both protective and therapeutic strategies against HCV infection. Human and mouse harbor a comparable system for antiviral type I interferon (IFN induction and amplification, which regulates viral infection and replication. Using hepatocytes from knockout (ko mice, we determined the critical step of the IFN-inducing/amplification pathways regulating HCV replication in mouse. The results infer that interferon-beta promoter stimulator (IPS-1 or interferon A receptor (IFNAR were a crucial barrier to HCV replication in mouse hepatocytes. Although both IFNARko and IPS-1ko hepatocytes showed a reduced induction of type I interferons in response to viral infection, only IPS-1-/- cells circumvented cell death from HCV cytopathic effect and significantly improved J6JFH1 replication, suggesting IPS-1 to be a key player regulating HCV replication in mouse hepatocytes. We then established mouse hepatocyte lines lacking IPS-1 or IFNAR through immortalization with SV40T antigen. Expression of human (hCD81 on these hepatocyte lines rendered both lines HCVcc-permissive. We also found that the chimeric J6JFH1 construct, having the structure region from J6 isolate enhanced HCV replication in mouse hepatocytes rather than the full length original JFH1 construct, a new finding that suggests the possible role of the HCV structural region in HCV replication. This is the first report on the entry and replication of HCV infectious particles in mouse hepatocytes. These mouse hepatocyte lines will facilitate establishing a mouse HCV infection model with multifarious applications.

  14. Proliferation of L02 human hepatocytes in tolerized geneticall yimmunocompetent rats

    Institute of Scientific and Technical Information of China (English)

    Hu Lin; Qing Mao; Yu-Ming Wang; Li Jiang

    2008-01-01

    AIM: To investigate whether human hepatocytes could proliferate after transplantation to normal immunocompetent rats treated with 2-acetaminofluorene or Retrorsine and partial hepatectomy.METHODS: L02 hepatocyte-tolerant Sprague-Dawley rats were injected with Retrorsine, 2-acetaminofluorene or normal saline. L02 hepatocytes were then transplanted via the spleen. Human albumin and its mRNA, specific proliferating cell nuclear antigen (PCNA), L02 hepatocyte dynamic distribution, number density and area density of PCNA-positive cells in the liver were determined.RESULTS: All the examined indicators were not significantly different between the rats treated with 2-acetaminofluorene and normal saline, which was not the case with rats treated with Retrorsine. A dynamic distribution of L02 hepatocytes in the rat liver was detected from wk 1 to mo 6 after transplantation in the Retrorsine group and from wk 1 to 10 in the 2-acetaminofluorene group. Human albumin and its mRNA were detected from wk 2 to mo 6 in the Retrorsine group and from wk 1 to 8 in the 2-acetaminofiuorene group.Specific human PCNA was detected in the rat liver from wk 2 to mo 6 in the Retrorsine group and from wk 2 to 6 in the 2-acetaminofluorene group. Human albumin and its mRNA contents as well as the number of PCNA positive cells reached a peak at wk 4.CONCLUSION: L02 human hepatocytes could not proliferate significiantly after transplantation to the normal,immunocompetent rats treated with 2-acetaminofluorene.L02 human hepatocytes can survive for 10 wk after transplantation and express human albumin for 8 wk. L02human hepatocytes can proliferate and express human albumin for 6 mo after transplantation to the rats treated with Retrorsine. The chimeric L02 human hepatocytes,which then underwent transplantation into tolerant rats,were normal in morphogenesis, biochemistry and function.

  15. Role of apoptotic hepatocytes in HCV dissemination: regulation by acetaldehyde.

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    Ganesan, Murali; Natarajan, Sathish Kumar; Zhang, Jinjin; Mott, Justin L; Poluektova, Larisa I; McVicker, Benita L; Kharbanda, Kusum K; Tuma, Dean J; Osna, Natalia A

    2016-06-01

    Alcohol consumption exacerbates hepatitis C virus (HCV) pathogenesis and promotes disease progression, although the mechanisms are not quite clear. We have previously observed that acetaldehyde (Ach) continuously produced by the acetaldehyde-generating system (AGS), temporarily enhanced HCV RNA levels, followed by a decrease to normal or lower levels, which corresponded to apoptosis induction. Here, we studied whether Ach-induced apoptosis caused depletion of HCV-infected cells and what role apoptotic bodies (AB) play in HCV-alcohol crosstalk. In liver cells exposed to AGS, we observed the induction of miR-122 and miR-34a. As miR-34a has been associated with apoptotic signaling and miR-122 with HCV replication, these findings may suggest that cells with intensive viral replication undergo apoptosis. Furthermore, when AGS-induced apoptosis was blocked by a pan-caspase inhibitor, the expression of HCV RNA was not changed. AB from HCV-infected cells contained HCV core protein and the assembled HCV particle that infect intact hepatocytes, thereby promoting the spread of infection. In addition, AB are captured by macrophages to switch their cytokine profile to the proinflammatory one. Macrophages exposed to HCV(+) AB expressed more IL-1β, IL-18, IL-6, and IL-10 mRNAs compared with those exposed to HCV(-) AB. The generation of AB from AGS-treated HCV-infected cells even enhanced the induction of aforementioned cytokines. We conclude that HCV and alcohol metabolites trigger the formation of AB containing HCV particles. The consequent spread of HCV to neighboring hepatocytes via infected AB, as well as the induction of liver inflammation by AB-mediated macrophage activation potentially exacerbate the HCV infection course by alcohol and worsen disease progression.

  16. Evidence against a stem cell origin of new hepatocytes in a common mouse model of chronic liver injury.

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    Schaub, Johanna R; Malato, Yann; Gormond, Coralie; Willenbring, Holger

    2014-08-21

    Hepatocytes provide most liver functions, but they can also proliferate and regenerate the liver after injury. However, under some liver injury conditions, particularly chronic liver injury where hepatocyte proliferation is impaired, liver stem cells (LSCs) are thought to replenish lost hepatocytes. Conflicting results have been reported about the identity of LSCs and their contribution to liver regeneration. To address this uncertainty, we followed candidate LSC populations by genetic fate tracing in adult mice with chronic liver injury due to a choline-deficient, ethionine-supplemented diet. In contrast to previous studies, we failed to detect hepatocytes derived from biliary epithelial cells or mesenchymal liver cells beyond a negligible frequency. In fact, we failed to detect hepatocytes that were not derived from pre-existing hepatocytes. In conclusion, our findings argue against LSCs, or other nonhepatocyte cell types, providing a backup system for hepatocyte regeneration in this common mouse model of chronic liver injury.

  17. Evidence against a Stem Cell Origin of New Hepatocytes in a Common Mouse Model of Chronic Liver Injury

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    Johanna R. Schaub

    2014-08-01

    Full Text Available Hepatocytes provide most liver functions, but they can also proliferate and regenerate the liver after injury. However, under some liver injury conditions, particularly chronic liver injury where hepatocyte proliferation is impaired, liver stem cells (LSCs are thought to replenish lost hepatocytes. Conflicting results have been reported about the identity of LSCs and their contribution to liver regeneration. To address this uncertainty, we followed candidate LSC populations by genetic fate tracing in adult mice with chronic liver injury due to a choline-deficient, ethionine-supplemented diet. In contrast to previous studies, we failed to detect hepatocytes derived from biliary epithelial cells or mesenchymal liver cells beyond a negligible frequency. In fact, we failed to detect hepatocytes that were not derived from pre-existing hepatocytes. In conclusion, our findings argue against LSCs, or other nonhepatocyte cell types, providing a backup system for hepatocyte regeneration in this common mouse model of chronic liver injury.

  18. Role of Nuclear Constitutive Androstane Receptor in Regulation of Hepatocyte Proliferation and Hepatocarcinogenesis.

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    Kazantseva, Y A; Pustylnyak, Y A; Pustylnyak, V O

    2016-04-01

    Activation of the constitutive androstane receptor (CAR) in hepatocytes occurs as a body adaptation in response to a number of external influences, and its functional activity is primarily related to induction of enzymes detoxifying xenobiotics. However, special attention was recently given to CAR due to the fact that its key role becomes unveiled in various physiological and pathophysiological processes occurring in the liver: gluconeogenesis, metabolism of fatty acids and bilirubin, hormonal regulation, proliferation of hepatocytes, and hepatocarcinogenesis. Here we review the main pathways and mechanisms that elevate hepatocyte proliferative activity related to CAR and whose disturbance may be a pivotal factor in hepatocarcinogenesis.

  19. In vitro drug metabolism of green tea catechins in human, monkey, dog, rat and mouse hepatocytes.

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    Chen, Wendy W; Qin, Geng-Yao; Zhang, Ting; Feng, Wan-Yong

    2012-06-01

    The metabolic fate of green tea catechins [(-)-epicatechin ((-)-EC), (-)-epicatechin-3-gallate (ECG) (-)- epigallocatechin (EGC) and (-)-epigallocatechin-3-gallate (EGCG)] in cryopreserved human, monkey, dog, rat and mouse hepatocytes was studied. Methylation, glucuronidation, sulfation and isomerization pathways of (-)-EC in all five species were found. Methylation, glucuronidation, sulfation, hydrolysis, isomerization and glucosidation pathways of ECG were found. Species differences in metabolism of (-)-EC or ECG were observed. Surprisingly, no metabolites of EGC or EGCG were detected, but chemical oxidation and polymerization were observed under these experimental conditions. It appeared that enzymatic reactions and chemical reactions were differentiated by an additional hydroxyl group on the B-ring between (-)-EC/ECG and EGC/EGCG. For (-)-EC, thirty-five metabolites including isomerized (M6. M10 and M25), glucuronidated (M3, M5 and M11), sulfated (M7, M15, M16, M18, M20, M23, M26), methylated (M2, M9, M12, M17, M19, M21, M27, M30, M32), glucuronated/methylated (M4, M8, M13, M14), sulfated/methylated (M22, M24, M28, M29, M31, M33, M34, M35) and diglucuronidate (M1), were detected and characterized. M11, M18, M19 and M23 were major metabolites in human hepatocytes; M11, M26 and M31 were major metabolites in monkey hepatocytes; M10, M20, M22, M26 and M31 were major metabolites in dog hepatocytes; M5, M6 and M10 were major metabolites in rat hepatocytes; and M5, M6 and M13 were major metabolites in mouse hepatocytes. For ECG, twelve metabolites including isomerized (M1), hydrolyzed (M3), glucosidated (M2), glucuronidated (M4 and M6), sulfated (M9, M11 and M12), methylated (M7), sulfated/glucuronidated/methylated (M8 and M10) and diglucuronidated (M5), were detected and characterized. M4, M11 and M12 were major metabolites in human hepatocytes; M11 and M12 were major metabolites in monkey hepatocytes; M3 and M11 were major metabolites in dog hepatocytes; M4, M6 and

  20. Recombinant Laminins Drive the Differentiation and Self-Organization of hESC-Derived Hepatocytes

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    Kate Cameron

    2015-12-01

    Full Text Available Stem cell-derived somatic cells represent an unlimited resource for basic and translational science. Although promisin