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Hepatocyte Cultures (hepatocyte + culture)

Distribution by Scientific Domains
Medical Sciences73%
Life Sciences13%

Kinds of Hepatocyte Cultures

  • rat hepatocyte culture
    		•

    Selected Abstracts

    Induction of Transferrin Receptor by Ethanol in Rat Primary Hepatocyte Culture

    ALCOHOLISM, Issue 2004
    Masako Suzuki
    Background: It is not uncommon for alcoholics to have iron accumulation in the liver, a condition that may contribute to the development of alcoholic liver disease. Recently, we reported that the expression of transferrin receptor, which mediates cellular iron uptake, was increased in hepatocytes in patients with alcoholic liver disease. To elucidate the mechanism of the iron accumulation in hepatocytes in such disease, we examined whether ethanol exposure induced the transferrin receptor expression and increased the cellular iron uptake. Methods: Rat primary hepatocytes were isolated and cultured in the presence of 20 ,mol/liter of iron and 25 mmol/liter of ethanol. Results: Ethanol exposure to the hepatocytes demonstrated an ,2-fold increase in transferrin receptor expression for 24 hr, shown by Western blot analysis and 35S-methionine metabolic labeling, 19% increase in 59Fe-transferrin uptake by hepatocytes, and 20% increase in activity of iron regulatory protein examined by band shift assay. Conclusion: Ethanol exposure induced the transferrin receptor expression, partially through the activation of iron regulatory protein, and increased the transferrin-bound iron uptake in rat hepatocyte cultures. The induction of transferrin receptor by ethanol might be one of the mechanisms of iron accumulation in the hepatocytes in alcoholic liver disease. [source]

    Primary hepatocyte culture supports hepatitis C virus replication: A model for infection-associated hepatocarcinogenesis,

    HEPATOLOGY, Issue 6 2010
    Krishna Banaudha
    Analysis of progressive changes in hepatic gene expression that underlie hepatocarcinogenesis following hepatitis C virus (HCV) infection require examination of long-term cultures of normally differentiating primary human hepatocytes. We report a culture system of primary hepatocytes that support productive replication of infectious HCV. Hepatic functions were analyzed by reverse-transcription polymerase chain reaction amplification of total cell RNA from cultures maintained in serum-free defined medium for up to 190 days. Sustained hepatic function was assessed by expression of albumin, alpha-fetoprotein, cytochrome P4502E1, cytokeratin-18, type-1 collagen, transforming growth factor-beta 1, matrix metalloproteinase-2 (MMP-2), MMP-13, and interferon alpha-receptors 1 and 2. Normally differentiated human primary hepatocytes supported productive replication of infectious clones of HCV genotypes 1a, 1b, and 2a; virus infection was inhibited by antibodies against CD81 virus entry factor. Virus released into the culture media of HCV-infected primary hepatocytes repeatedly passage to naïve hepatocytes. Replication of the three HCV genotypes shows interferon sensitivity observed in natural infections. Conclusion: Sustained cultures of physiologic host cells for the propagation of infectious HCV strains should accelerate studies of host response to HCV infection and progressive liver disease. Hepatology 2010;51:1922,1932 [source]

    Hepatocyte dynamics in a three-dimensional rotating bioreactor

    JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 11 2007
    Mitsuo Miyazawa
    Abstract Background and Aims:, The use of an artificial liver system with extracorporeal circulation or a three-dimensional bioreactor perfused with liquid culture medium inevitably exposes hepatocytes to fluid mechanical stress (MS). The expression of liver-specific hepatocyte functions seems to be modulated by the magnitude of MS. Nonetheless, few studies have focused on the direct effects of MS on hepatocytes. We subjected hepatocytes to MS using an MS loading device and investigated the effects on the cytoskeleton and hepatocyte dynamics inside three-dimensional scaffolds by monitoring the changes in actin fiber, one of the components of the cytoskeleton. We also assessed the influence of MS on specific hepatocyte functions. Methods:, We subjected hepatocytes to MS by a rotating radial flow bioreactor (RRFB) and examined the effects by comparing the MS-loaded culture cells with cells cultured under stationary conditions without MS loading. The hepatocytes (1 × 106/cm3) were seeded on gauze without collagen coating and examined to determine morphological changes after 60 h incubation. Actin filaments in samples from the MS-loaded hepatocyte culture were stained by fluorescein isothiocyanate-labeled phalloidin. Results:, Hepatocyte aggregation was observed in the MS-loaded culture, but not in the unloaded stationary culture. Better albumin products were observed in the MS-loaded group than in the stationary culture group at all measurement points. Actin filaments extended toward the scaffold after the start of MS loading incubation and polymerized around the hepatocytes. The hepatocyte aggregation eventually advanced to the formation of spheroids. Conclusion:, These results suggest that MS-induced polymerization of actin filaments stimulate hepatocyte aggregation and thereby improve hepatocyte-specific function. [source]

    Evaluation of Modified CMC and CMC-PVA as Miscible Polymer Blend Membranes for Hepatocytes

    MACROMOLECULAR BIOSCIENCE, Issue 5 2007
    Aysel Koç
    Abstract CMC and CMC-PVA were blended either with type I collagen, BSA or CS to obtain biocompatible membranes for evaluation as potential hepatocyte culture substrates. Pure and modified forms of CMC showed distinct surface, mechanical, and cell attachment properties. While the hydrophilicity decreased, the mechanical stability and the porosity of CMC membranes increased after blending. Serum proteins were adsorbed by all types of membranes. Among eight membranes tested, collagen-modified CMC was found to be a suitable membrane material for hepatocyte culture, in terms of mechanical and cell interaction properties. [source]

    Hepatoprotective and antioxidant effects of Alnus japonica extracts on acetaminophen-induced hepatotoxicity in rats

    PHYTOTHERAPY RESEARCH, Issue 12 2004
    Sang Tae Kim
    Abstract The stem bark of the Betulaceae plant Alnus japonica, which is indigenous to Korea, has been used as a popular folk medicine for hepatitis and cancer. In this study, the antioxidant activity of the crude extract and the hepatoprotective activities on acetaminophen (AAP)-induced toxicity in the rat liver were evaluated. We investigated the effect of the methanol (AJM) and solvent fracton of the stem bark of Alnus japonica (AJ) on AAP-induced hepatotoxicity in rats. In rat hepatocyte culture, pretreatment with AJM (50, 100, 150 and 200 µg[sol ]ml) significantly decreased the cytotoxicity of AAP in a dose-dependent manner. The pretreated with EtOAc and BuOH fraction led to an increase in free radical scavenging activity and a decrease in inhibition of lipid peroxidation, both superoxide dismutase and catalase prevent the hepatotoxicity by AAP in the treatment of A. japonica fraction. We conclude that AJ is an important antioxidant in AAP-induced live hepatotoxicity and that extract of AJM plays a hepatoprotective effects in the against AAP-induced cytotoxicity in cultured rat hepatocytes in vitro. Pending more evaluation for safety and efficacy, AJ can potentially be used in mitigating AAP-induced hepatotoxicity. Copyright © 2004 John Wiley & Sons, Ltd. [source]

    2,3,4,7,8-pentachlorodibenzofuran is a more potent cytochrome P4501A inducer than 2,3,7,8-tetrachlorodibenzo- p -dioxin in herring gull hepatocyte cultures

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 9 2010
    Jessica C. Hervé
    Abstract Concentration-dependent effects of 2,3,7,8-tetrachlorodibenzo- p -dioxin (TCDD), 2,3,4,7,8-pentachlorodibenzofuran (PeCDF), and 2,3,7,8-tetrachlorodibenzofuran (TCDF) on cytochrome P4501A (CYP1A) induction were determined in primary cultures of embryonic herring gull (Larus argentatus) hepatocytes exposed for 24,h. Based on the concentration that induced 50% of the maximal response (EC50), the relative potencies of TCDD and TCDF did not differ by more than 3.5-fold. However, also based on the EC50, PeCDF was 40-fold, 21-fold, and 9.8-fold more potent for inducing ethoxyresorufin- O -deethylase (EROD) activity, CYP1A4 mRNA expression, and CYP1A5 mRNA expression than TCDD, respectively. The relative CYP1A-inducing potencies of PeCDF and of other dioxin-like chemicals (DLCs) in herring gull hepatocytes (HEH RePs), along with data on concentrations of DLCs in Great Lakes herring gull eggs, were used to calculate World Health Organization toxic equivalent (WHO-TEQ) concentrations and herring gull embryonic hepatocyte toxic equivalent (HEH-TEQ) concentrations. The analysis indicated that, when using avian toxic equivalency factors (TEFs) recommended by the WHO, the relative contribution of TCDD (1.1,10.2%) to total WHO-TEQ concentration was higher than that of PeCDF (1.7,2.9%). These results differ from the relative contribution of TCDD and PeCDF when HEH RePs were used; PeCDF was a major contributor (36.5,52.9%) to total HEH-TEQ concentrations, whereas the contribution by TCDD (1.2,10.3%) was less than that of PeCDF. The WHO TEFs for avian species were largely derived from studies with the domestic chicken (Gallus gallus domesticus). The findings of the present study suggest that it is necessary to determine the relative potencies of DLCs in wild birds and to re-evaluate their relative contributions to the biochemical and toxic effects previously reported in herring gulls and other avian species. Environ. Toxicol. Chem. 2010;29:2088,2095. © 2010 SETAC [source]

    Gap junction-mediated intercellular communication in a long-term primary mouse hepatocyte culture system

    HEPATOLOGY, Issue 5 2003
    Stephanie A. Stoehr
    Gap junction-mediated intercellular communication (GJIC) is critical for maintaining integral cellular processes including differentiation and growth control. The disruption of GJIC has been correlated with aberrant function in many cell types, including hepatocytes in vivo; therefore it is imperative that cellular model systems support intercellular communication to simulate normal cellular functions. Functional GJIC has been shown in long-term primary rat hepatocyte cultures, which have been implemented widely to study various aspects of hepatocellular function; however, the onset of transgenic technology in murine species has necessitated the development of a primary mouse hepatocyte system. In this report, we analyze GJIC in a dimethylsulfoxide (DMSO)-containing long-term primary mouse hepatocyte culture system. The cells retain morphologic and biochemical characteristics of differentiated hepatocytes through day 30 post plating, including liver-specific gene expression. We further show that connexin32 and connexin26 expression and gap junction plaque formation increase over time in culture concomitant with an increase in GJIC between adjoining primary mouse hepatocytes. In conclusion, the findings described in this study make it possible to maintain differentiated primary mouse hepatocytes that also show GJIC in long-term culture for 30 days. In addition, this system has the potential to be extended to study primary mouse hepatocytes isolated from genetically engineered mice. [source]

    Regulation of multidrug resistance 2 P-glycoprotein expression by bile salts in rats and in primary cultures of rat hepatocytes

    HEPATOLOGY, Issue 2 2000
    Seema Gupta
    Biliary phospholipid secretion is tightly coupled to the secretion of free cholesterol and bile salts. The secretion of phospholipids across the canalicular membrane of hepatocytes occurs via the multidrug resistance 2 (mdr2) P-glycoprotein (Pgp). The mechanism underlying the coupling of bile salt and phospholipid secretion has not been elucidated. The aims of this study were to determine the effects of bile acid structure on the expression of mdr2 in vitro and in vivo. Under optimal culture conditions, taurine-conjugated bile acids (50 ,mol/L) increased mdr2 messenger RNA (mRNA) levels in the following order: taurocholate (TCA) (288 ± 36%, P < .005) = taurodeoxycholate (TDCA) (276 ± 36%, P < .025) > taurochenodeoxycholate (TCDCA) (216 ± 34%, P < .025) > tauroursodeoxycholate (TUDCA) (175 ± 28%, P < .05) of control levels. The increase in mdr2 mRNA levels by TCA was both time and concentration dependent. Cholate feeding to rats with intact enterohepatic circulation increased mdr2 transcriptional activity by 4-fold and protein mass by 1.9-fold. Chronic biliary diversion (CBD) decreased mdr2 mRNA levels to 66 ± 9% (P < .025) of sham-operated controls. Intraduodenal infusion of TCA for 48 hours in CBD rats caused a significant increase in mdr2 mRNA levels (224%) as compared with CBD controls. A diet high in cholesterol (4%) decreased mdr2 mRNA levels to 57% ± 2 (P < .001) of pair-fed controls. Squalestatin (1 ,mol/L), an inhibitor of cholesterol biosynthesis, increased mdr2 mRNA levels by 8.8-fold (P < .005) in hepatocyte cultures after 24 hours. In conclusion, in the rat, bile acids up-regulated mdr2 transcriptional activity whereas cholesterol decreased mdr2 mRNA both in vitro and in vivo. [source]

    Modulation of UDP-glucuronosyltransferase 1A1 in primary human hepatocytes by prototypical inducers,

    JOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 2 2005
    Cornelia M. Smith
    Abstract The primary objective of this study was to evaluate the modulation of UGT1A1 expression in human hepatocytes using prototypical CYP450 inducers. A bank of 16 human livers was utilized to obtain an estimate of the range of UGT1A1 protein expression and catalytic activity. Concentration-dependent changes in UGT1A1 response were evaluated in hepatocyte cultures after treatment with 3-methylchloranthrene, ,-napthoflavone, rifampicin, or phenobarbital. Pharmacodynamic analyses of UGT1A1 expression were conducted and compared to those of CYP450 after treatment with inducers in 2,3 different hepatocyte preparations. Additionally, expression of UGT1A1 mRNA and protein was evaluated in human hepatocytes treated with 14 different compounds known to activate differentially the human pregnane-X-receptor or constitutive androstane receptor. Pharmacodynamic modeling revealed EC50 values statistically significant between UGT1A1 and CYP2B6 after treatment with PB, but not statistically distinguishable between UGT1A1 and CYP's 1A2 or 3A4 after treatment with 3-methylchloranthrene or rifampicin, respectively. UGT1A1 was most responsive to the pregnane-X-receptor-agonists rifampicin, ritonavir, and clotrimazole at the mRNA level and, to a lesser extent, the constitutive androstane receptor-activators, phenobarbital and phenytoin. Pharmacodynamic analyses support a mechanism of coordinate regulation between UGT1A1 and a number of CYP450 enzymes by multiple nuclear receptors. © 2005 Wiley Periodicals, Inc. J Biochem Mol Toxicol 19:96,108, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20058 [source]

    Induction of Transferrin Receptor by Ethanol in Rat Primary Hepatocyte Culture

    ALCOHOLISM, Issue 2004
    Masako Suzuki
    Background: It is not uncommon for alcoholics to have iron accumulation in the liver, a condition that may contribute to the development of alcoholic liver disease. Recently, we reported that the expression of transferrin receptor, which mediates cellular iron uptake, was increased in hepatocytes in patients with alcoholic liver disease. To elucidate the mechanism of the iron accumulation in hepatocytes in such disease, we examined whether ethanol exposure induced the transferrin receptor expression and increased the cellular iron uptake. Methods: Rat primary hepatocytes were isolated and cultured in the presence of 20 ,mol/liter of iron and 25 mmol/liter of ethanol. Results: Ethanol exposure to the hepatocytes demonstrated an ,2-fold increase in transferrin receptor expression for 24 hr, shown by Western blot analysis and 35S-methionine metabolic labeling, 19% increase in 59Fe-transferrin uptake by hepatocytes, and 20% increase in activity of iron regulatory protein examined by band shift assay. Conclusion: Ethanol exposure induced the transferrin receptor expression, partially through the activation of iron regulatory protein, and increased the transferrin-bound iron uptake in rat hepatocyte cultures. The induction of transferrin receptor by ethanol might be one of the mechanisms of iron accumulation in the hepatocytes in alcoholic liver disease. [source]

    Gender-incompatible liver transplantation is not a risk factor for patient survival

    LIVER INTERNATIONAL, Issue 2 2009
    Frank Lehner
    Abstract Background/Aims: Clinical data may be suggestive for differences in patient survival in gender-incompatible orthotopic liver transplantation (OLT), but findings are inconsistent and are putatively linked to circulating hormones. We therefore investigated patient survival as well as metabolism of steroids to identify possible causes of improved graft survival in gender-mismatched OLT. Methods: We examined our single-centre database of 1355 recipients of first liver transplants for overall patient survival by non-parametric and parametric analysis of multivariance taking the age of recipient and donor, ischaemia time, underlying liver disease and the time period of transplantation into account. Furthermore, the metabolism of androgens in gender-incompatible OLT was studied in cultures of primary human hepatocytes obtained from male and female patients. Results: Unlike previous studies we were unable to determine overall significant differences in patient survival in gender-incompatible OLT, even though a statistically significant improved patient survival was observed when male donor livers were transplanted into female recipients in univariant analysis (P=0.047). However, when the overall patient management was taken into account no difference in survival was determined in multivariant analysis. Importantly, the metabolism of testosterone did not differ between male and female hepatocyte cultures, except for the production of 6-,-hydroxy-testosterone (P<0.001). Conclusions: Taken collectively, clinical observations may tend to suggest a slightly improved patient survival in gender-incompatible OLT but this cannot be explained on the bases of androgen metabolism. Overall, we view gender-incompatible liver transplantation not to be a confounder in patient survival after OLT. [source]

    Hepatocyte Function in a Radial-flow Bioreactor Using a Perfluorocarbon Oxygen Carrier

    ARTIFICIAL ORGANS, Issue 11 2005
    Martin J. Nieuwoudt
    Abstract:, The aims of this study were, first, to indicate the metabolic activity of hepatocytes in a radial-flow polyurethane foam matrix bioreactor relative to monocultures, and second, to evaluate the effect on the hepatocytes of including a synthetic perfluorocarbon (PFC) oxygen carrier to the recirculating medium. The efficient O2 -carrying ability of PFCs may be beneficial to bioreactors employed in stressed cellular environments. Thus, they may also be useful in the treatment of an acute liver failure patient with a bioartificial liver support system (BALSS). Data on the function of three-dimensional (3-D) hepatocyte cultures exposed to emulsified PFCs are lacking. Results: the metabolic functions of the 3-D hepatocyte cultures were improved relative to monocultures. Three-dimensional cultures with and without PFC behaved similarly, and no adverse effects could be detected when PFC was included in the recirculating medium. The addition of PFC significantly improved lidocaine clearance possibly due to the presence of higher O2 tension in the medium. Imaging indicated that large aggregates formed and that seeding had followed flow through the matrix. Simulations indicated first, that the cell numbers used in this study had been insufficient to challenge the bioreactor O2 supply explaining the similarity in performance of the 3-D cultures, and second, that the benefit of adding PFC would be more pronounced at the cell densities likely to be used in a BALSS bioreactor. [source]

    Inhibition of NF-,B activation by the histone deacetylase inhibitor 4-Me2N-BAVAH induces an early G1 cell cycle arrest in primary hepatocytes

    CELL PROLIFERATION, Issue 5 2007
    P. Papeleu
    4-Me2N-BAVAH has been shown to induce histone hyperacetylation and to inhibit proliferation in Friend erythroleukaemia cells in vitro. However, the molecular mechanisms have remained unidentified. Materials and Methods:,In this study, we evaluated the effects of 4-Me2N-BAVAH on proliferation in non-malignant cells, namely epidermal growth factor-stimulated primary rat hepatocytes. Results and Conclusion:,We have found that 4-Me2N-BAVAH inhibits HDAC activity at non-cytotoxic concentrations and prevents cells from responding to the mitogenic stimuli of epidermal growth factor. This results in an early G1 cell cycle arrest that is independent of p21 activity, but instead can be attributed to inhibition of cyclin D1 transcription through a mechanism involving inhibition of nuclear factor-kappaB activation. In addition, 4-Me2N-BAVAH delays the onset of spontaneous apoptosis in primary rat hepatocyte cultures as evidenced by down-regulation of the pro-apoptotic proteins Bid and Bax, and inhibition of caspase-3 activation. [source]

    An inhibitor of interleukin-6 trans-signalling, sgp130, contributes to impaired acute phase response in human chronic liver disease

    CLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2009
    A. Lemmers
    Summary In chronic liver disease, high circulating interleukin (IL)-6 contrasts with a poor acute phase response. We evaluated the impact of liver and circulating IL-6-receptor (IL-6R) forms on IL-6 bioactivity in chronic liver disease. IL-6, soluble IL-6-receptor and sgp130 levels were assayed in plasma from 45 patients with alcoholic liver disease, 84 with hepatitis C virus (HCV) infection undergoing transjugular liver biopsies and 15 healthy subjects. IL-6R mRNA was quantified on liver extracts from 54 patients with alcoholic liver disease with or without cirrhosis and 18 HCV-infected patients. The effect of gp130,Fc on fibrinogen secretion induced by IL-6 trans-signalling was evaluated on hepatocyte cultures. Levels of plasma IL-6 and sgp130, but not soluble IL-6R, increased with the stage of chronic liver disease, and correlated significantly with disease severity. Alcoholic liver disease patients had higher plasma IL-6 levels than hepatitis C, but lower liver IL-6R expression. In alcoholic and HCV-related liver diseases, liver IL-6R expression decreased with advanced fibrosis stage. In vitro, on hepatocytes, gp130,Fc blunted the acute phase response while soluble IL-6R enhanced IL-6 stimulation. In advanced chronic liver disease, high plasma IL-6 is associated with low liver IL-6R expression. This situation enables high plasma sgp130 to act as a major negative regulator of liver IL-6 trans-signalling, as demonstrated functionally here on hepatocytes. This might explain the poor acute phase response induced by IL-6 in chronic liver disease. [source]