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Sample records for body forming hepatocytes

  1. Whole-body γ-irradiation decelerates rat hepatocyte polyploidization.

    Science.gov (United States)

    Ikhtiar, Adnan M

    2015-07-01

    To characterize hepatocyte polyploidization induced by intermediate dose of γ-ray. Male Wistar strain rats were whole-body irradiated (WBI) with 2 Gy of γ-ray at the age of 1 month, and 5-6 rats were sacrificed monthly at 0-25 months after irradiation. The nuclear DNA content of individual hepatocytes was measured by flow cytometry, then hepatocytes were classified into various ploidy classes. Survival percentage, after exposure up to the end of the study, did not indicate any differences between the irradiated groups and controls. The degree of polyploidization in hepatocytes of irradiated rats, was significantly lower than that for the control after 1 month of exposure, and it continued to be lower after up to 8 months. Thereafter, the degree of polyploidization in the irradiated group slowly returned to the control level when the irradiated rats reached the age of 10 months. Intermediate dose of ionizing radiation, in contrast to high doses, decelerate hepatocyte polyploidization, which may coincides with the hypothesis of the beneficial effects of low doses of ionizing radiation.

  2. Whole-body X-irradiation of mice accelerates polyploidization of hepatocytes

    International Nuclear Information System (INIS)

    Shima, A.; Egami, N.

    1985-01-01

    Male C57BL/6 mice were whole-body irradiated with 4.75 gy of X-rays at the age of 2 months and killed at 2, 6, 12 and 19 months after irradiation. The percentage survival began to decline earlier and faster in the irradiated group than the controls up to 19 months after exposure when the study was terminated. The nuclear DNA content of individual hepatocytes was measured by a Feulgen-DNA microfluorometric method, and hepatocytes were classified into various ploidy classes. In the irradiated mice, the degree of polyploidization was significantly higher than the controls by 2 months after exposure and steadily increased up to 6 months after exposure. Thereafter, however, a slow return to the control level was found up to 19 months after irradiation. These results appear to support a hypothesis that radiation accelerates the ageing process as judged from hepatocyte polyploidization. (author)

  3. Recovery of important physiological functions in 3D culture of immortal hepatocytes

    DEFF Research Database (Denmark)

    Wrzesinski, Krzysztof; Fey, S. J.

    2011-01-01

    to grow human liver cells in ‘3 dimensional’ cultures so that they behave very similar to the liver in our bodies. By growing the immortal hepatocytes in specially designed bioreactors they form small pieces of ‘pseudotissue’ which exhibit several of the functions seen in the adult liver. We have grown...

  4. Comparison of the effects of the synthetic pyrethroid Metofluthrin and phenobarbital on CYP2B form induction and replicative DNA synthesis in cultured rat and human hepatocytes

    International Nuclear Information System (INIS)

    Hirose, Yukihiro; Nagahori, Hirohisa; Yamada, Tomoya; Deguchi, Yoshihito; Tomigahara, Yoshitaka; Nishioka, Kazuhiko; Uwagawa, Satoshi; Kawamura, Satoshi; Isobe, Naohiko; Lake, Brian G.; Okuno, Yasuyoshi

    2009-01-01

    High doses of Metofluthrin (MTF) have been shown to produce liver tumours in rats by a mode of action (MOA) involving activation of the constitutive androstane receptor leading to liver hypertrophy, induction of cytochrome P450 (CYP) forms and increased cell proliferation. The aim of this study was to compare the effects of MTF with those of the known rodent liver tumour promoter phenobarbital (PB) on the induction CYP2B forms and replicative DNA synthesis in cultured rat and human hepatocytes. Treatment with 50 μM MTF and 50 μM PB for 72 h increased CYP2B1 mRNA levels in male Wistar rat hepatocytes and CYP2B6 mRNA levels in human hepatocytes. Replicative DNA synthesis was determined by incorporation of 5-bromo-2'-deoxyuridine over the last 24 h of a 48 h treatment period. Treatment with 10-1000 μM MTF and 100-500 μM PB resulted in significant increases in replicative DNA synthesis in rat hepatocytes. While replicative DNA synthesis was increased in human hepatocytes treated with 5-50 ng/ml epidermal growth factor or 5-100 ng/ml hepatocyte growth factor, treatment with MTF and PB had no effect. These results demonstrate that while both MTF and PB induce CYP2B forms in both species, MTF and PB only induced replicative DNA synthesis in rat and not in human hepatocytes. These results provide further evidence that the MOA for MTF-induced rat liver tumour formation is similar to that of PB and some other non-genotoxic CYP2B form inducers and that the key event of increased cell proliferation would not occur in human liver

  5. Comparison of the effects of the synthetic pyrethroid Metofluthrin and phenobarbital on CYP2B form induction and replicative DNA synthesis in cultured rat and human hepatocytes.

    Science.gov (United States)

    Hirose, Yukihiro; Nagahori, Hirohisa; Yamada, Tomoya; Deguchi, Yoshihito; Tomigahara, Yoshitaka; Nishioka, Kazuhiko; Uwagawa, Satoshi; Kawamura, Satoshi; Isobe, Naohiko; Lake, Brian G; Okuno, Yasuyoshi

    2009-04-05

    High doses of Metofluthrin (MTF) have been shown to produce liver tumours in rats by a mode of action (MOA) involving activation of the constitutive androstane receptor leading to liver hypertrophy, induction of cytochrome P450 (CYP) forms and increased cell proliferation. The aim of this study was to compare the effects of MTF with those of the known rodent liver tumour promoter phenobarbital (PB) on the induction CYP2B forms and replicative DNA synthesis in cultured rat and human hepatocytes. Treatment with 50 microM MTF and 50 microM PB for 72 h increased CYP2B1 mRNA levels in male Wistar rat hepatocytes and CYP2B6 mRNA levels in human hepatocytes. Replicative DNA synthesis was determined by incorporation of 5-bromo-2'-deoxyuridine over the last 24 h of a 48 h treatment period. Treatment with 10-1000 microM MTF and 100-500 microM PB resulted in significant increases in replicative DNA synthesis in rat hepatocytes. While replicative DNA synthesis was increased in human hepatocytes treated with 5-50 ng/ml epidermal growth factor or 5-100 ng/ml hepatocyte growth factor, treatment with MTF and PB had no effect. These results demonstrate that while both MTF and PB induce CYP2B forms in both species, MTF and PB only induced replicative DNA synthesis in rat and not in human hepatocytes. These results provide further evidence that the MOA for MTF-induced rat liver tumour formation is similar to that of PB and some other non-genotoxic CYP2B form inducers and that the key event of increased cell proliferation would not occur in human liver.

  6. Study on radioprotection of alliin and damage mechanism in hepatocyte after irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Tae Jeong; Kim, Won Tae [Dept, of Radiological Science, Kaya University, Kimhae (Korea, Republic of)

    2016-12-15

    Liver tissue damage by a radiation exposure caused a jaundice and ascitic fluid e form harden atrophy. The reason for this lies in morphological damage of a liver cells. This study tried that observe damage mechanism of the cell organelles. It was especially observed mitochondria, endoplasmic reticulum and nuclear membrane associated with energy metabolizable. also, This study had with a radio-protector development research at the same time. Radio-protector was used to alliin that has an blood flow increase. Cell observation make used of transmission electron microscope(TEM). The result of an experiment, 7Gy of whole body irradiation was caused an inflammation in cell organelles and hypertrophy of the nucleus membrane. After 20 days, The hepatocyte has been observed in a damaged membrane on peroxisome, mitochondria and vacuole of the cell organelles. After 30 days, The hepatocyte has been observed in disconnected ribosomes on a rough endoplasmic reticulum. There was looked a giant lipoblast. There was clearly normal observed a mitochondria and nucleus membrane in the hepatocyte after alliin injection. aslo, It was no damaged the nucleus membrane. Therefore, It was identified portion a radio-protector effect from alliin.

  7. The neural basis of body form and body action agnosia.

    Science.gov (United States)

    Moro, Valentina; Urgesi, Cosimo; Pernigo, Simone; Lanteri, Paola; Pazzaglia, Mariella; Aglioti, Salvatore Maria

    2008-10-23

    Visual analysis of faces and nonfacial body stimuli brings about neural activity in different cortical areas. Moreover, processing body form and body action relies on distinct neural substrates. Although brain lesion studies show specific face processing deficits, neuropsychological evidence for defective recognition of nonfacial body parts is lacking. By combining psychophysics studies with lesion-mapping techniques, we found that lesions of ventromedial, occipitotemporal areas induce face and body recognition deficits while lesions involving extrastriate body area seem causatively associated with impaired recognition of body but not of face and object stimuli. We also found that body form and body action recognition deficits can be double dissociated and are causatively associated with lesions to extrastriate body area and ventral premotor cortex, respectively. Our study reports two category-specific visual deficits, called body form and body action agnosia, and highlights their neural underpinnings.

  8. Hepatocytes, rather than leukocytes reverse DNA damage in vivo induced by whole body y-irradiation of mice, as shown by the alkaline comet assay

    Directory of Open Access Journals (Sweden)

    JUANA PINCHEIRA

    2008-01-01

    Full Text Available DNA damage repair was assessed in quiescent (G0 leukocytes and in hepatocytes of mice, after 1 and 2 hours recovery from a single whole body y-irradiation with 0.5, 1 or 2 Gy. Evaluation of single-strand breaks (SSB and alkali-labile sites together were carried out by a single-cell electrophoresis at pH>13.0 (alkaline comet assay. In non-irradiated (control mice, the constitutive, endogenous DNA damage (basal was around 1.5 times higher in leukocytes than in hepatocytes. Irradiation immediately increased SSB frequency in both cell types, in a dose-dependent manner. Two sequential phases took place during the in vivo repair of the radio-induced DNA lesions. The earliest one, present in both hepatocytes and leukocytes, further increased the SSB frequency, making evident the processing of some primary lesions in DNA bases into the SSB repair intermediates. In a second phase, SSB frequency decreased because of their removal. In hepatocytes, such a frequency regressed to the constitutive basal level after 2 hours recovery from either 0.5 orí Gy. On the other hand, the SSB repair phase was specifically abrogated in leukocytes, at the doses and recovery times analyzed. Thus, the efficiency of in vivo repair of radio-induced DNA damage in dormant cells (lymphocytes is quite different from that in hepatocytes whose low proliferation activity accounts only for cell renewal.

  9. Generation of human hepatocytes by stem cell technology: definition of the hepatocyte.

    Science.gov (United States)

    Hengstler, Jan G; Brulport, Marc; Schormann, Wiebke; Bauer, Alexander; Hermes, Matthias; Nussler, Andreas K; Fandrich, Fred; Ruhnke, Maren; Ungefroren, Hendrik; Griffin, Louise; Bockamp, Ernesto; Oesch, Franz; von Mach, Marc-Alexander

    2005-06-01

    Since 1999, numerous articles have reported the generation of hepatocytes from different types of extrahepatic stem or precursor cells. This opens exciting new possibilities for pharmacology and toxicology, as well as for cell therapy. Hepatocyte marker expression, including albumin, cytokeratin 18, c-met, alpha-fetoprotein and cytochrome P450 3A4 and -2B6, has been observed after transplantation of different types of human stem cells into the liver of laboratory animals or in vitro after incubation with cytokines. These intriguing observations have prompted scientists to classify stem cell-derived cell populations as hepatocytes. However, this conclusion may be premature. It has been shown that factors of the liver microenvironment can induce expression of a limited number of hepatocyte marker genes in nonhepatic cell types. To conclude on the grounds of a limited number of markers that these cells are true hepatocytes is not indicated. In this case one should carefully evaluate crucial hepatocyte-defining enzymatic properties. The present article: i) reviews studies describing the fate of extrahepatic human stem and precursor cells in livers of laboratory animals, including the possibility of cell fusion; and ii) critically discusses the phenotype of stem cells after application of various differentiation protocols aimed at generating human hepatocytes. In addition, the necessary criteria needed for defining a true hepatocyte are suggested. Establishing the necessary properties for stem cell-derived hepatocytes is timely and reasonable, and thus avoids further misleading semantic confusion. Finally, it is essential to understand that the definition of a bona fide hepatocyte should not be limited to qualitative assays, such as reverse transcriptase polymerase chain reaction and immunohistochemistry, but has to include a quantitative analysis of enzymatic activities, which allows direct comparison with primary hepatocytes. Although the stem cell-derived-hepatocyte

  10. Method of forming aluminum oxynitride material and bodies formed by such methods

    Science.gov (United States)

    Bakas, Michael P [Ammon, ID; Lillo, Thomas M [Idaho Falls, ID; Chu, Henry S [Idaho Falls, ID

    2010-11-16

    Methods of forming aluminum oxynitride (AlON) materials include sintering green bodies comprising aluminum orthophosphate or another sacrificial material therein. Such green bodies may comprise aluminum, oxygen, and nitrogen in addition to the aluminum orthophosphate. For example, the green bodies may include a mixture of aluminum oxide, aluminum nitride, and aluminum orthophosphate or another sacrificial material. Additional methods of forming aluminum oxynitride (AlON) materials include sintering a green body including a sacrificial material therein, using the sacrificial material to form pores in the green body during sintering, and infiltrating the pores formed in the green body with a liquid infiltrant during sintering. Bodies are formed using such methods.

  11. Efficient derivation of functional hepatocytes from mouse induced pluripotent stem cells by a combination of cytokines and sodium butyrate

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qi; YANG Yang; ZHANG Jian; WANG Guo-ying; LIU Wei; QIU Dong-bo; HEI Zi-qing; YING Qi-long; CHEN Gui-hua

    2011-01-01

    Background Hepatocyte transplantation has been proposed as an alternative to whole-organ transplantation to support many forms of hepatic insufficiency.Unfortunately,the lack of donor livers makes it difficult to obtain enough viable human hepatocytes for hepatocyte-based therapies.Therefore,it is urgent to find new ways to provide ample hepatocytes.Induced pluripotent stem (iPS) cells,a breakthrough in stem cell research,may terminate these hinders for cell transplantation.For the promise of iPS cells to be realized in liver diseases,it is necessary to determine if and how efficient they can be differentiated into functional hepatocytes.Methods In this study,we directly compared the hepatic-differentiation capacity of mouse iPS cells and embryonic stem (ES) cells with three different induction approaches:conditions via embryonic body (EB) formation plus cytokines,conditions by combination of dimethyl sulfoxide and sodium butyrate and chemically defined,serum free monolayer conditions.Among these three induction conditions,more homogenous populations can be promoted under chemically defined,serum free conditions.The cells generated under these conditions exhibited hepatic functions in vitro,including glycogen storage,indocynine green (ICG) uptake and release as well as urea secretion.Although efficient hepatocytes differentiation from mouse iPS cells were observed,mouse iPS cells showed relatively lower hepatic induction efficiency compared with mouse ES cells.Results Mouse iPS cells would be efficiently differentiated into functional hepatocytes in vitro,which may be helpful in facilitating the development of hepatocytes for transplantation and for research on drug discovery.Conclusion We demonstrate that mouse iPS cells retain full potential for fetal liver development and describe procedures that facilitates the efficient generation of highly differentiated human hepatocyte-like cells from iPS cells in vitro.

  12. TGFbeta Induces Binucleation/Polyploidization in Hepatocytes through a Src-Dependent Cytokinesis Failure.

    Science.gov (United States)

    De Santis Puzzonia, Marco; Cozzolino, Angela Maria; Grassi, Germana; Bisceglia, Francesca; Strippoli, Raffaele; Guarguaglini, Giulia; Citarella, Franca; Sacchetti, Benedetto; Tripodi, Marco; Marchetti, Alessandra; Amicone, Laura

    2016-01-01

    In all mammals, the adult liver shows binucleated as well as mononucleated polyploid hepatocytes. The hepatic polyploidization starts after birth with an extensive hepatocyte binucleation and generates hepatocytes of several ploidy classes. While the functional significance of hepatocyte polyploidy is becoming clearer, how it is triggered and maintained needs to be clarified. Aim of this study was to identify a major inducer of hepatocyte binucleation/polyploidization and the cellular and molecular mechanisms involved. We found that, among several cytokines analyzed, known to be involved in early liver development and/or mass control, TGFbeta1 was capable to induce, together with the expected morphological changes, binucleation in hepatocytes in culture. Most importantly, the pharmacological inhibition of TGFbeta signaling in healthy mice during weaning, when the physiological binucleation occurs, induced a significant decrease of hepatocyte binucleation rate, without affecting cell proliferation and hepatic index. The TGFbeta-induced hepatocyte binucleation resulted from a cytokinesis failure, as assessed by video microscopy, and is associated with a delocalization of the cytokinesis regulator RhoA-GTPase from the mid-body of dividing cells. The use of specific chemical inhibitors demonstrated that the observed events are Src-dependent. Finally, the restoration of a fully epithelial phenotype by TGFbeta withdrawal gave rise to a cell progeny capable to maintain the polyploid state. In conclusion, we identified TGFbeta as a major inducer of hepatocyte binucleation both in vitro and in vivo, thus ascribing a novel role to this pleiotropic cytokine. The production of binucleated/tetraploid hepatocytes is due to a cytokinesis failure controlled by the molecular axis TGFbeta/Src/RhoA.

  13. TGFbeta Induces Binucleation/Polyploidization in Hepatocytes through a Src-Dependent Cytokinesis Failure.

    Directory of Open Access Journals (Sweden)

    Marco De Santis Puzzonia

    Full Text Available In all mammals, the adult liver shows binucleated as well as mononucleated polyploid hepatocytes. The hepatic polyploidization starts after birth with an extensive hepatocyte binucleation and generates hepatocytes of several ploidy classes. While the functional significance of hepatocyte polyploidy is becoming clearer, how it is triggered and maintained needs to be clarified. Aim of this study was to identify a major inducer of hepatocyte binucleation/polyploidization and the cellular and molecular mechanisms involved. We found that, among several cytokines analyzed, known to be involved in early liver development and/or mass control, TGFbeta1 was capable to induce, together with the expected morphological changes, binucleation in hepatocytes in culture. Most importantly, the pharmacological inhibition of TGFbeta signaling in healthy mice during weaning, when the physiological binucleation occurs, induced a significant decrease of hepatocyte binucleation rate, without affecting cell proliferation and hepatic index. The TGFbeta-induced hepatocyte binucleation resulted from a cytokinesis failure, as assessed by video microscopy, and is associated with a delocalization of the cytokinesis regulator RhoA-GTPase from the mid-body of dividing cells. The use of specific chemical inhibitors demonstrated that the observed events are Src-dependent. Finally, the restoration of a fully epithelial phenotype by TGFbeta withdrawal gave rise to a cell progeny capable to maintain the polyploid state. In conclusion, we identified TGFbeta as a major inducer of hepatocyte binucleation both in vitro and in vivo, thus ascribing a novel role to this pleiotropic cytokine. The production of binucleated/tetraploid hepatocytes is due to a cytokinesis failure controlled by the molecular axis TGFbeta/Src/RhoA.

  14. BODY SHAPE VERSUS BODY FORM: A COMPARISON OF THE ...

    African Journals Online (AJOL)

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    SWAZI CONSUMERS WITH THOSE OF BODY FORMS USED IN APPAREL .... China). Most South African apparel manufactu- rers are using sizing systems ... The issue of body image and ... exercise, it was explained to the participants that.

  15. Requirements of glycerol and fatty acid for triglyceride synthesis and ketogenesis by hepatocytes from normal and triiodothyronine-treated rats

    International Nuclear Information System (INIS)

    Olubadewo, J.O.; Heimberg, M.

    1985-01-01

    Hepatocytes from T3-treated rats synthesized less triglyceride and more ketone bodies from [1- 14 C]oleate at all concentrations from 0-2 mM, than did hepatocytes from euthyroid animals; addition of 1.0 mM glycerol increased triglyceride synthesis and reduced ketogenesis in hepatocytes from T3-treated rats to the rates observed in euthyroid hepatocytes in the absence of added glycerol. Glycerol did not alter triglyceride synthesis, but reduced ketogenesis genesis by euthyroid hepatocytes. It is probable from these and other data that, in the hyperthyroid rat, glycero-3-P, and not fatty acid, is rate limiting for synthesis of triglyceride, and, secondarily for reducing rates of ketogenesis in the hepatocyte

  16. Comparison of the biological features between human fetal hepatocyte and immortalized L-02 hepatocyte in vitro

    International Nuclear Information System (INIS)

    Kong Weiwei; Teng Gaojun

    2004-01-01

    Objective: To evaluate the feasibilities of the potential donors in liver cell transplantation using the human fetal hepatocytes and immortalized L-02 hepatocytes by comparing their biological features. Methods: Human fetal hepatocytes were isolated from aborted fetal livers (gestational ages from 14 w to 24 w) by an improved two-stage perfusion method and cultured in a conditioned medium without any growth factors. α-fetal protein (AFP) and albumin (ALB) were detected by radioimmunoassay (RIA) and cytokeratin-19 (CK-19 ) was identified by cellular immunochemistry study. Immortalized L-02 hepatocytes were cultured in the same condition and the characteristic proteins were detected by the same methods. Results: The viability of human fetal hepatocytes was approximately 95% using the perfusion method, and the maximum survival time of the cultured hepatocytes was 3 weeks. The expression of AFP, ALB, and CK19 was detected at the same time, especially during Day 3 to Day 7 in the culture. By comparison, the proliferation ability of L-02 hepatocyte was greater, although with a lower level of ALB secretion. The expression of AFP and CK19 was not detected. Furthermore, during the long culture, L-02 hepatocytes may undergo a morphologic change and fail to express ALB. Conclusion: Human fetal hepatocyte may be a practical donor for hepatocyte transplantation with its high-level protein expression and potential bi-differentiation ability. In view of the absent expression of ALB and the morphologic change in culture, although with better proliferation, L-02 hepatocyte seems not useful for hepatocyte transplantation

  17. [Changes in the chromatin structure of hepatocyte nuclei of rats trained to hypoxia].

    Science.gov (United States)

    Domkina, L K; Bresler, V M; Simanovskiĭ, L N

    1976-03-01

    Structure of chromatin in the nuclei of the isolated surviving hepatocytes and in the isolated nuclei of hepatocytes were studied by fluorochroming with acridine orange and by microfluorimetry of fluorescenc connected with the stain chromatin at 530 and 590 nm in intact rats and in the animals trained to hypoxia in a pressure chamber for 60 days. The nuclei of hepatocytes of intact rats were distributed by fluorescence at 530 nm into three classes with the intensity ratio of 1:2:4; as to the nuclei of hepatocytes of the rats trained to hypoxia - they formed a single class corresponding to the second class of control. In intact rats the ratio of the fluorescence intensity at 590 nm to such at 530 nm (alpha coefficient) formed normal distribution; in trained rats - a bimodal distribution with a shift of the maximum in the direction of reduction and increase of alpha in comparison with control. It is supposed that in hypoxia there is a repression of one and depression of other genes in the chromatine of the nuclei of the liver.

  18. Role of CYP2B in Phenobarbital-Induced Hepatocyte Proliferation in Mice.

    Science.gov (United States)

    Li, Lei; Bao, Xiaochen; Zhang, Qing-Yu; Negishi, Masahiko; Ding, Xinxin

    2017-08-01

    Phenobarbital (PB) promotes liver tumorigenesis in rodents, in part through activation of the constitutive androstane receptor (CAR) and the consequent changes in hepatic gene expression and increases in hepatocyte proliferation. A typical effect of CAR activation by PB is a marked induction of Cyp2b10 expression in the liver; the latter has been suspected to be vital for PB-induced hepatocellular proliferation. This hypothesis was tested here by using a Cyp2a(4/5)bgs -null (null) mouse model in which all Cyp2b genes are deleted. Adult male and female wild-type (WT) and null mice were treated intraperitoneally with PB at 50 mg/kg once daily for 5 successive days and tested on day 6. The liver-to-body weight ratio, an indicator of liver hypertrophy, was increased by 47% in male WT mice, but by only 22% in male Cyp2a(4/5)bgs -null mice, by the PB treatment. The fractions of bromodeoxyuridine-positive hepatocyte nuclei, assessed as a measure of the rate of hepatocyte proliferation, were also significantly lower in PB-treated male null mice compared with PB-treated male WT mice. However, whereas few proliferating hepatocytes were detected in saline-treated mice, many proliferating hepatocytes were still detected in PB-treated male null mice. In contrast, female WT mice were much less sensitive than male WT mice to PB-induced hepatocyte proliferation, and PB-treated female WT and PB-treated female null mice did not show significant difference in rates of hepatocyte proliferation. These results indicate that CYP2B induction plays a significant, but partial, role in PB-induced hepatocyte proliferation in male mice. U.S. Government work not protected by U.S. copyright.

  19. Cell proliferation studies in rodent hepatocytes during 1,4-dichlorobenzene administration

    International Nuclear Information System (INIS)

    Eldridge, S.R.; Tilbury, L.F.; Randall, H.; Goldsworthy, T.L.; Butterworth, B.E.

    1990-01-01

    In the NTP bioassay, 1,4-dichlorobenzene (DCB) induced hepatocellular carcinomas in mice, but not in rats. Because DCB is not DNA reactive, a cell proliferation study under conditions of the bioassay was undertaken to determine whether increased cell proliferation might play a role in DCB-induced hepatocarcinogenicity. DCB was administered in corn oil by gavage at the highest bioassay dose to male B6C3F1 mice (600 mg/kg) and male F344 rats (300 mg/kg) for five consecutive days. Cell proliferation was detected by labeling hepatocytes with either 5-bromo-2'-deoxyuridine (BRDU) or 3 H-thymidine delivered during the entire treatment period by subcutaneously implanted osmotic pumps. An increase in liver weight as a percentage of body weight was observed in treated mice (6.7±0.6 vs. 5.9±0.2) and rats (4.7±0.1 vs. 4.0±0.2) compared to controls. No significant elevations in plasma enzymes were found in either treated species, indicating a lack of overt hepatotoxicity. Histopathological evaluation revealed no evidence of hepatotoxicity in either species. The percentage of hepatocytes in S-phase was increased approximately 10-fold in both treated mice and rats compared to the respective control animals. Mice exhibited a centrilobular pattern of labeled hepatocytes, whereas rat hepatocytes were labeled hepatocytes, whereas rat hepatocytes were labeled throughout the lobules. These data demonstrate the hepatic mitogenic activity of DCB in mice and rats. However, this response dose not correlate with DCB-induced hepatocarcinogenicity. Further studies are required to examine the extent, duration and nature of the proliferative response in order to understand the species-specific effects of DCB

  20. Hepatocyte transplants improve liver function and encephalopathy in portacaval shunted rats.

    Science.gov (United States)

    Fogel, Wieslawa Agnieszka; Stasiak, Anna; Maksymowicz, Michał; Kobos, Jozef; Unzeta, Mercedes; Mussur, Miroslaw

    2014-07-01

    Rats with portacaval shunt (PCS) are useful experimental models of human hepatic encephalopathy in chronic liver dysfunction. We have previously shown that PCS modifies amine neurotransmitter systems in the CNS and increases voluntary alcohol intake by rats. Hepatocyte transplantation, used in acute liver failure, has recently also been applied to chronic liver diseases, which prompted us to investigate whether the altered brain amine system and the drinking behavior in long-term shunted rats could be normalized by hepatocyte transplants. Hepatocytes, isolated from syngeneic donors by collagenase digestion, were injected (3 × 10(6) cells/rat) into the pancreatic tail region, 6 months after PCS. Hepatic function was evaluated by measuring urine urea and plasma L-histidine concentrations. A free choice test with two bottles (tap water and 10% ethyl alcohol) was performed for 3 days to assess the rats' preference for alcohol. The rats were euthanized 2 months posttransplantation. Brain histamine and 5-hydroxyindoleacetic acid (5-HIAA) levels were measured by radioenzymatic assay and by HPLC-EC, respectively, N-tele-methylhistamine by GC/MS while MAOA and MAOB activities by isotopic procedures. Portacaval shunt rats with hepatocyte transplants gave more urea than before transplantation, with lower plasma L-His levels and higher body weight versus the PCS counterparts. Also, those rats consumed less alcohol. The CNS amines and 5-HIAA concentrations, as well as MAO-B activity, being abnormally high in untreated PCS rats, significantly reduced after PCS hepatocyte treatment. The results support the therapeutic values of hepatocyte transplants in chronic liver diseases and the temporary character of PCS-exerted CNS dysfunctions. © 2014 John Wiley & Sons Ltd.

  1. 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

  2. Repolarization of hepatocytes in culture.

    Science.gov (United States)

    Talamini, M A; Kappus, B; Hubbard, A

    1997-01-01

    We have evaluated the biochemical, morphological, and functional redevelopment of polarity in freshly isolated hepatocytes cultured using a double layer collagen gel sandwich technique. Western blot analysis showed increased cellular levels of the cell adhesion protein uvomorulin as cultured hepatocytes repolarized. Immunofluorescence studies using antibodies against domain-specific membrane proteins showed polarity as early as 48 hours, although the pattern of the polymeric Immunoglobulin-A receptor (pIgA-R) differed from in vivo liver. Electron microscopy showed developing bile canaliculi at 1 day. However, the functional presence of tight junctions was absent at 1 day, but present at 5 days. We further showed functional polarity to be present at 4 days by documenting the ability of cultured hepatocytes to metabolize and excrete fluorescein diacetate into visible bile canaliculi. We conclude that hepatocytes cultured appropriately develop morphological and functional polarity. Hepatocyte culture is therefore a useful tool for the study of mechanisms responsible for the development of polarized function.

  3. Glutamic Acid as Enhancer of Protein Synthesis Kinetics in Hepatocytes from Old Rats.

    Science.gov (United States)

    Brodsky, V Y; Malchenko, L A; Butorina, N N; Lazarev Konchenko, D S; Zvezdina, N D; Dubovaya, T K

    2017-08-01

    Dense cultures of hepatocytes from old rats (~2 years old, body weight 530-610 g) are different from similar cultures of hepatocytes from young rats by the low amplitude of protein synthesis rhythm. Addition of glutamic acid (0.2, 0.4, or 0.6 mg/ml) into the culture medium with hepatocytes of old rats resulted in increase in the oscillation amplitudes of the protein synthesis rhythm to the level of young rats. A similar action of glutamic acid on the protein synthesis kinetics was observed in vivo after feeding old rats with glutamic acid. Inhibition of metabotropic receptors of glutamic acid with α-methyl-4-carboxyphenylglycine (0.01 mg/ml) abolished the effect of glutamic acid. The amplitude of oscillation of the protein synthesis rhythm in a cell population characterizes synchronization of individual oscillations caused by direct cell-cell communications. Hence, glutamic acid, acting as a receptor-dependent transmitter, enhanced direct cell-cell communications of hepatocytes that were decreased with aging. As differentiated from other known membrane signaling factors (gangliosides, norepinephrine, serotonin, dopamine), glutamic acid can penetrate into the brain and thus influence the communications and protein synthesis kinetics that are disturbed with aging not only in hepatocytes, but also in neurons.

  4. Comparison of para-aminophenol cytotoxicity in rat renal epithelial cells and hepatocytes.

    Science.gov (United States)

    Li, Ying; Bentzley, Catherine M; Tarloff, Joan B

    2005-04-01

    Several chemicals, including para-aminophenol (PAP), produce kidney damage in the absence of hepatic damage. Selective nephrotoxicity may be related to the ability of the kidney to reabsorb filtered water, thereby raising the intraluminal concentration of toxicants and exposing tubular epithelial cells to higher concentrations than would be present in other tissues. The present experiments tested the hypothesis that hepatocytes and renal epithelial cells exposed to equivalent concentrations of PAP would be equally susceptible to toxicity. Hepatocytes and renal epithelial cells were prepared by collagenase digestion of tissues obtained from female Sprague-Dawley rats. Toxicity was monitored using trypan blue exclusion, oxygen consumption and ATP content. We measured the rate of PAP clearance and formation of PAP-glutathione conjugate by HPLC. We found that renal epithelial cells accumulated trypan blue and showed declines in oxygen consumption and ATP content at significantly lower concentrations of PAP and at earlier time points than hepatocytes. The half-life of PAP in hepatocyte incubations was significantly shorter (0.71+/-0.07 h) than in renal epithelial cell incubations (1.33+/-0.23 h), suggesting that renal epithelial cells were exposed to PAP for longer time periods than hepatocytes. Renal epithelial cells formed significantly less glutathione conjugates of PAP (PAP-SG) than did hepatocytes, consistent with less efficient detoxification of reactive PAP intermediates by renal epithelial cells. Finally, hepatocytes contained significant more reduced glutathione (NPSH) than did renal epithelial cells, possibly explaining the enhanced formation of PAP-SG by this cell population. In conclusion, our data indicates that renal epithelial cells are intrinsically more susceptible to PAP cytotoxicity than are hepatocytes. This enhanced cytotoxicity may be due to longer exposure to PAP and/or reduced detoxification of reactive intermediates due to lower concentrations

  5. Posttranslational modification of hepatic cytochrome P-450. Phosphorylation of phenobarbital-inducible P-450 forms PB-4 (IIB1) and PB-5 (IIB2) in isolated rat hepatocytes and in vivo

    International Nuclear Information System (INIS)

    Koch, J.A.; Waxman, D.J.

    1989-01-01

    Phosphorylation of hepatic cytochrome P-450 was studied in isolated hepatocytes incubated in the presence of agents known to stimulate protein kinase activity. Incubation of hepatocytes isolated from phenobarbital-induced adult male rats with [ 32 P]orthophosphate in the presence of N 6 , O 2' -dibutyryl-cAMP (diBtcAMP) or glucagon resulted in the phosphorylation of microsomal proteins that are immunoprecipitable by polyclonal antibodies raised to the phenobarbital-induced P-450 form PB-4 (P-450 gene IIB1). Two-dimensional gel electrophoresis revealed that these 32 P-labeled microsomal proteins consist of a mixture of P-450 PB-4 and the closely related P-450 PB-5 (gene IIB2), both of which exhibited heterogeneity in the isoelectric focusing dimension. Phosphorylation of both P-450 forms was markedly enhanced by diBtcAMP at concentrations as low as 5 μM. Phosphoamino acid analysis of the 32 P-labeled P-450 PB-4 + PB-5 immunoprecipitate revealed that these P-450s are phosphorylated on serine in the isolated hepatocytes. Peptide mapping indicated that the site of phosphorylation in hepatocytes is indistinguishable from the site utilized by cAMP-dependent protein kinase in vitro, which was previously identified as serine-128 for the related rabbit protein P-450 LM2. In vitro analyses revealed that phosphorylation of P-450 PB-4 leads to a loss of monooxygenase activity, suggesting that the posttranslational modification of this P-450 enzyme by cAMP-dependent protein kinase may play a role in the modulation of P-450-dependent monooxygenase activity in vivo

  6. Induction of unscheduled DNA synthesis on the nuclear matrix of rat hepatocytes after whole-body γ-irradiation

    International Nuclear Information System (INIS)

    Bezlepkin, V.G.; Malinovskij, Yu.Yu.; Kuznetsova, E.A.; Namvar, R.A.; Gaziev, A.I.

    1986-01-01

    DNA synthesis in hepatocytes was studied by incorporation of [ 3 H]thymidine administered of portal vein of γ-irradiated (80 Gy) rats. It was shown that the rate of replicative DNA synthesis decreased in hepatocytes of the regenerating liver and unscheduled DNA synthesis was induced at the nuclear matrix of resting cells of the intact liver. In addition to repair synthesis, DNA synthesis resembling replicative one (''aberrant'' DNA synthesis) accounts for a considerable fraction of γ-radiation-induced synthesis of DNA at the nuclear matrix

  7. Hanging Drop, A Best Three-Dimensional (3D) Culture Method for Primary Buffalo and Sheep Hepatocytes.

    Science.gov (United States)

    Shri, Meena; Agrawal, Himanshu; Rani, Payal; Singh, Dheer; Onteru, Suneel Kumar

    2017-04-26

    Livestock, having close resemblance to humans, could be a better source of primary hepatocytes than rodents. Herein, we successfully developed three-dimensional (3D) culturing system for primary sheep and buffalo hepatocytes. The 3D-structures of sheep hepatocytes were formed on the fifth-day and maintained until the tenth-day on polyHEMA-coated plates and in hanging drops with William's E media (HDW). Between the cultured and fresh cells, we observed a similar expression of GAPDH, HNF4α, ALB, CYP1A1, CK8 and CK18. Interestingly, a statistically significant increase was noted in the TAT, CPS, AFP, AAT, GSP and PCNA expression. In buffalo hepatocytes culture, 3D-like structures were formed on the third-day and maintained until the sixth-day on polyHEMA and HDW. The expression of HNF4α, GSP, CPS, AFP, AAT, PCNA and CK18 was similar between cultured and fresh cells. Further, a statistically significant increase in the TAT and CK8 expression, and a decrease in the GAPDH, CYP1A1 and ALB expression were noted. Among the culture systems, HDW maintained the liver transcript markers more or less similar to the fresh hepatocytes of the sheep and buffalo for ten and six days, respectively. Taken together, hanging drop is an efficient method for 3D culturing of primary sheep and buffalo hepatocytes.

  8. Hepatocyte nuclear factor 4A improves hepatic differentiation of immortalized adult human hepatocytes and improves liver function and survival.

    Science.gov (United States)

    Hang, Hua-Lian; Liu, Xin-Yu; Wang, Hai-Tian; Xu, Ning; Bian, Jian-Min; Zhang, Jian-Jun; Xia, Lei; Xia, Qiang

    2017-11-15

    Immortalized human hepatocytes (IHH) could provide an unlimited supply of hepatocytes, but insufficient differentiation and phenotypic instability restrict their clinical application. This study aimed to determine the role of hepatocyte nuclear factor 4A (HNF4A) in hepatic differentiation of IHH, and whether encapsulation of IHH overexpressing HNF4A could improve liver function and survival in rats with acute liver failure (ALF). Primary human hepatocytes were transduced with lentivirus-mediated catalytic subunit of human telomerase reverse transcriptase (hTERT) to establish IHH. Cells were analyzed for telomerase activity, proliferative capacity, hepatocyte markers, and tumorigenicity (c-myc) expression. Hepatocyte markers, hepatocellular functions, and morphology were studied in the HNF4A-overexpressing IHH. Hepatocyte markers and karyotype analysis were completed in the primary hepatocytes using shRNA knockdown of HNF4A. Nuclear translocation of β-catenin was assessed. Rat models of ALF were treated with encapsulated IHH or HNF4A-overexpressing IHH. A HNF4A-positive IHH line was established, which was non-tumorigenic and conserved properties of primary hepatocytes. HNF4A overexpression significantly enhanced mRNA levels of genes related to hepatic differentiation in IHH. Urea levels were increased by the overexpression of HNF4A, as measured 24h after ammonium chloride addition, similar to that of primary hepatocytes. Chromosomal abnormalities were observed in primary hepatocytes transfected with HNF4A shRNA. HNF4α overexpression could significantly promote β-catenin activation. Transplantation of HNF4A overexpressing IHH resulted in better liver function and survival of rats with ALF compared with IHH. HNF4A improved hepatic differentiation of IHH. Transplantation of HNF4A-overexpressing IHH could improve the liver function and survival in a rat model of ALF. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Phenotypic and functional analyses show stem cell-derived hepatocyte-like cells better mimic fetal rather than adult hepatocytes.

    Science.gov (United States)

    Baxter, Melissa; Withey, Sarah; Harrison, Sean; Segeritz, Charis-Patricia; Zhang, Fang; Atkinson-Dell, Rebecca; Rowe, Cliff; Gerrard, Dave T; Sison-Young, Rowena; Jenkins, Roz; Henry, Joanne; Berry, Andrew A; Mohamet, Lisa; Best, Marie; Fenwick, Stephen W; Malik, Hassan; Kitteringham, Neil R; Goldring, Chris E; Piper Hanley, Karen; Vallier, Ludovic; Hanley, Neil A

    2015-03-01

    Hepatocyte-like cells (HLCs), differentiated from pluripotent stem cells by the use of soluble factors, can model human liver function and toxicity. However, at present HLC maturity and whether any deficit represents a true fetal state or aberrant differentiation is unclear and compounded by comparison to potentially deteriorated adult hepatocytes. Therefore, we generated HLCs from multiple lineages, using two different protocols, for direct comparison with fresh fetal and adult hepatocytes. Protocols were developed for robust differentiation. Multiple transcript, protein and functional analyses compared HLCs to fresh human fetal and adult hepatocytes. HLCs were comparable to those of other laboratories by multiple parameters. Transcriptional changes during differentiation mimicked human embryogenesis and showed more similarity to pericentral than periportal hepatocytes. Unbiased proteomics demonstrated greater proximity to liver than 30 other human organs or tissues. However, by comparison to fresh material, HLC maturity was proven by transcript, protein and function to be fetal-like and short of the adult phenotype. The expression of 81% phase 1 enzymes in HLCs was significantly upregulated and half were statistically not different from fetal hepatocytes. HLCs secreted albumin and metabolized testosterone (CYP3A) and dextrorphan (CYP2D6) like fetal hepatocytes. In seven bespoke tests, devised by principal components analysis to distinguish fetal from adult hepatocytes, HLCs from two different source laboratories consistently demonstrated fetal characteristics. HLCs from different sources are broadly comparable with unbiased proteomic evidence for faithful differentiation down the liver lineage. This current phenotype mimics human fetal rather than adult hepatocytes. Copyright © 2014 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

  10. Magnetic cell labeling of primary and stem cell-derived pig hepatocytes for MRI-based cell tracking of hepatocyte transplantation.

    Directory of Open Access Journals (Sweden)

    Dwayne R Roach

    Full Text Available Pig hepatocytes are an important investigational tool for optimizing hepatocyte transplantation schemes in both allogeneic and xenogeneic transplant scenarios. MRI can be used to serially monitor the transplanted cells, but only if the hepatocytes can be labeled with a magnetic particle. In this work, we describe culture conditions for magnetic cell labeling of cells from two different pig hepatocyte cell sources; primary pig hepatocytes (ppHEP and stem cell-derived hepatocytes (PICM-19FF. The magnetic particle is a micron-sized iron oxide particle (MPIO that has been extensively studied for magnetic cell labeling for MRI-based cell tracking. ppHEP could endocytose MPIO with labeling percentages as high as 70%, achieving iron content as high as ~55 pg/cell, with >75% viability. PICM-19FF had labeling >97%, achieving iron content ~38 pg/cell, with viability >99%. Extensive morphological and functional assays indicated that magnetic cell labeling was benign to the cells. The results encourage the use of MRI-based cell tracking for the development and clinical use of hepatocyte transplantation methodologies. Further, these results generally highlight the importance of functional cell assays in the evaluation of contrast agent biocompatibility.

  11. Generation of Hepatocyte-like Cells from Human Induced Pluripotent Stem (iPS) Cells By Co-culturing Embryoid Body Cells with Liver Non-parenchymal Cell Line TWNT-1

    International Nuclear Information System (INIS)

    Javed, M. S.; Yaqoob, N.; Iwamuro, M.; Kobayashi, N.; Fujiwara, T.

    2014-01-01

    Objective: To generate a homogeneous population of patient-specific hepatocyte-like cells (HLCs) from human iPS cells those show the morphologic and phenotypic properties of primary human hepatocytes. Study Design: An experimental study. Place and Duration of Study: Department of Surgery, Okayama University, Graduate School of Medicine, Japan, from April to December 2011. Methodology: Human iPS cells were generated and maintained on ES qualified matrigel coated plates supplemented with mTeSR medium or alternatively on mitotically inactivated MEF feeder layer in DMEM/F12 medium containing 20% KOSR, 4ng/ml bFGF-2, 1 x 10-4 M 2-mercaptoethanol, 1 mmol/L NEAA, 2mM L-glutamine and 1% penicillin-streptomycin. iPS cells were differentiated to HLCs by sequential culture using a four step differentiation protocol: (I) Generation of embryoid bodies (EBs) in suspension culture; (II) Induction of definitive endoderm (DE) from 2 days old EBs by growth in human activin-A (100 ng/ml) and basic fibroblasts growth factor (bFGF2) (100 ng/ml) on matrigel coated plates; (III) Induction of hepatic progenitors by co-culture with non-parenchymal human hepatic stellate cell line (TWNT-1); and (IV) Maturation by culture in dexamethasone. Characterization was performed by RT-PCR and functional assays. Results: The generated HLCs showed microscopically morphological phenotype of human hepatocytes, expressed liver specific genes (ASGPR, Albumin, AFP, Sox17, Fox A2), secreted human liver-specific proteins such as albumin, synthesized urea and metabolized ammonia. Conclusion: Functional HLCs were generated from human iPS cells, which could be used for autologus hepatocyte transplantation for liver failure and as in vitro model for determining the metabolic and toxicological properties of drug compounds. (author)

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

    Directory of Open Access Journals (Sweden)

    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.

  13. Factor VIIa binding and internalization in hepatocytes

    DEFF Research Database (Denmark)

    Hjortoe, G; Sorensen, B B; Petersen, L C

    2005-01-01

    The liver is believed to be the primary clearance organ for coagulation proteases, including factor VIIa (FVIIa). However, at present, clearance mechanisms for FVIIa in liver are unknown. To obtain information on the FVIIa clearance mechanism, we investigated the binding and internalization...... no effect. HEPG2 cells internalized FVIIa with a rate of 10 fmol 10(-5) cells h(-1). In contrast to HEPG2 cells, FVIIa binding to primary rat hepatocytes was completely independent of TF, and excess unlabeled FVIIa partly reduced the binding of 125I-FVIIa to rat hepatocytes. Further, compared with HEPG2...... cells, three- to fourfold more FVIIa bound to rat primary hepatocytes, and the bound FVIIa was internalized at a faster rate. Similar FVIIa binding and internalization profiles were observed in primary human hepatocytes. Plasma inhibitors had no effect on FVIIa binding and internalization in hepatocytes...

  14. Selective insulin resistance in hepatocyte senescence

    International Nuclear Information System (INIS)

    Aravinthan, Aloysious; Challis, Benjamin; Shannon, Nicholas; Hoare, Matthew; Heaney, Judith; Alexander, Graeme J.M.

    2015-01-01

    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

  15. 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.

  16. Targeted deletion of hepatocyte Ikkβ confers growth advantages

    International Nuclear Information System (INIS)

    Koch, Katherine S.; Maeda, Shin; He, Guobin; Karin, Michael; Leffert, Hyam L.

    2009-01-01

    Mice lacking hepatocyte IKKβ (Ikkβ Δhep ) are defective in TNFα-activation of hepatocellular transcription factor NF-κB, and highly susceptible to hepatotoxicity. Following diethylnitrosamine (DEN) exposure, Ikkβ Δhep mice develop more hepatocellular carcinoma (HCC) than control mice due partly to enhanced DEN-induced hepatocyte death. Here we show that Ikkβ Δhep hepatocytes display growth advantages over normal hepatocytes consisting of precocious PCNA and cyclin D1 expression during liver regeneration (shortened hepatocyte G 0 → G 1 transitions), and enhanced recovery efficiency, cyclin D1 expression and cell proliferation after plating. Ex vivo deletion of Ikkβ also accelerates hepatocyte growth. Ikkβ Δhep hepatocyte proliferative responses show heightened sensitivity to TGFα and TNFα, and heightened expression of fibronectin, collagens I/III, nidogen, β-actin and integrin β1 mRNAs. These findings suggest that altered mitogen signaling and expression of extracellular matrix and its associated components underlie growth advantages. Increased HCC development in Ikkβ Δhep mice may also be caused by growth advantages of surviving Ikkβ-deleted hepatocytes.

  17. Generation of human pluripotent stem cell-derived hepatocyte-like cells for drug toxicity screening.

    Science.gov (United States)

    Takayama, Kazuo; Mizuguchi, Hiroyuki

    2017-02-01

    Because drug-induced liver injury is one of the main reasons for drug development failures, it is important to perform drug toxicity screening in the early phase of pharmaceutical development. Currently, primary human hepatocytes are most widely used for the prediction of drug-induced liver injury. However, the sources of primary human hepatocytes are limited, making it difficult to supply the abundant quantities required for large-scale drug toxicity screening. Therefore, there is an urgent need for a novel unlimited, efficient, inexpensive, and predictive model which can be applied for large-scale drug toxicity screening. Human embryonic stem (ES) cells and induced pluripotent stem (iPS) cells are able to replicate indefinitely and differentiate into most of the body's cell types, including hepatocytes. It is expected that hepatocyte-like cells generated from human ES/iPS cells (human ES/iPS-HLCs) will be a useful tool for drug toxicity screening. To apply human ES/iPS-HLCs to various applications including drug toxicity screening, homogenous and functional HLCs must be differentiated from human ES/iPS cells. In this review, we will introduce the current status of hepatocyte differentiation technology from human ES/iPS cells and a novel method to predict drug-induced liver injury using human ES/iPS-HLCs. Copyright © 2016 The Japanese Society for the Study of Xenobiotics. Published by Elsevier Ltd. All rights reserved.

  18. Metabolism of cysteine by cyteinesulfinate-independent pathway(s) in rat hepatocytes

    International Nuclear Information System (INIS)

    Stipanuk, M.H.; De La Rosa, J.; Drake, M.R.

    1986-01-01

    The metabolism of cysteine (CYS) and that of cysteinesulfinate (CSA) were studied in freshly isolated hepatocytes from fed rats. In incubations of rat hepatocytes with either 1 or 25 mM CSA, over 90% of the 14 CO 2 formed from [1- 14 C]CSA could be accounted for by production of hypotaurine plus taurine. In similar incubations with 1 or 25 mM CYS, only 4% of 14 CO 2 evolution from [1- 14 C]CYS could be accounted for by production of hypotaurine plus taurine. Addition of unlabeled CSA inhibited recovery of label from [1- 14 C]CYS as 14 CO 2 by 33%. Metabolism of CYS and of CSA were affected differently by addition of α-ketoglutarate, a cosubstrate for transamination, or of propargylglycine, an inhibitor of cystathionase activity. These data suggest that a substantial proportion of CYS is catabolized by CSA-independent pathways in the rat hepatocyte. Although addition of α-ketoglutarate to incubations of hepatocytes with CSA resulted in a marked increase in CSA catabolism via the transamination pathway, addition of keto acids to incubation systems had little or no effect on production of any metabolite from CYS. Thus, CYS transamination does not appear to be a major pathway of CYS metabolism in the hepatocyte. Inhibition of cystathionase with propargylglycine reduced both 14 CO 2 production from [1- 14 C]CYS and ammonia plus urea nitrogen production from CYS by about 50%; CSA catabolism was not affected. Thus, cleavage of cyst(e)ine by cystathionase may be an important physiological pathway for CYS catabolism in the liver

  19. [Inclusion Bodies are Formed in SFTSV-infected Human Macrophages].

    Science.gov (United States)

    Jin, Cong; Song, Jingdong; Han, Ying; Li, Chuan; Qiu, Peihong; Liang, Mifang

    2016-01-01

    The severe fever with thrombocytopenia syndrome virus (SFTSV) is a new member in the genus Phlebovirus of the family Bunyaviridae identified in China. The SFTSV is also the causative pathogen of an emerging infectious disease: severe fever with thrombocytopenia syndrome. Using immunofluorescent staining and confocal microscopy, the intracellular distribution of nucleocapsid protein (NP) in SFTSV-infected THP-1 cells was investigated with serial doses of SFTSV at different times after infection. Transmission electron microscopy was used to observe the ultrafine intracellular structure of SFTSV-infected THP-1 cells at different times after infection. SFTSV NP could form intracellular inclusion bodies in infected THP-1 cells. The association between NP-formed inclusion bodies and virus production was analyzed: the size of the inclusion body formed 3 days after infection was correlated with the viral load in supernatants collected 7 days after infection. These findings suggest that the inclusion bodies formed in SFTSV-infected THP-1 cells could be where the SFTSV uses host-cell proteins and intracellular organelles to produce new viral particles.

  20. Functional activity of the rats’ hepatocytes under cancerogenesis

    Directory of Open Access Journals (Sweden)

    V. V. Ivchuk

    2007-10-01

    Full Text Available Enzymatic activity in rat’s hepatocytes under carcinoma Geuren T8 development as well as after introduction of rhenium compounds and cis-platin were studied. It has been determined that the decrease of enzymatic activity contrary to the control animals has been observed under simultaneous injection of cis-platin and cluster rhenium compounds in a liposome form. That confirms possible hepatoprotective properties of the rhenium compounds.

  1. Contribution of several amino acids and lactate to gluconeogenesis in hepatocytes isolated from rats fed various diets

    International Nuclear Information System (INIS)

    Kaloyianni, M.; Freedland, R.A.

    1990-01-01

    The contribution under various nutritional regimens of several amino acids and lactate to gluconeogenesis was estimated by measuring the glucose formation from 14C-labeled substrates. Isolated rat hepatocytes were incubated for 60 min in a Krebs-Ringer bicarbonate buffer pH 7.4 containing lactate, pyruvate and all the amino acids at concentrations similar to their physiological levels found in rat plasma, with one precursor labeled in each flask. In all conditions, lactate was the major glucose precursor, providing over 60% of the glucose formed. Glutamine and alanine were the major amino acid precursors of glucose, contributing 9.8% and 10.6% of the glucose formed, respectively, in hepatocytes isolated from starved rats. Serine, glycine and threonine also contributed to gluconeogenesis in the starved liver cells at 2.6, 2.1 and 3.8%, respectively, of the glucose formed. The rate of glucose formation from the isolated hepatocytes of the starved rats and those fed either high protein or high fat was higher than that from rats fed a nonpurified diet

  2. Hepatocyte polyploidization and its association with pathophysiological processes.

    Science.gov (United States)

    Wang, Min-Jun; Chen, Fei; Lau, Joseph T Y; Hu, Yi-Ping

    2017-05-18

    A characteristic cellular feature of the mammalian liver is the progressive polyploidization of the hepatocytes, where individual cells acquire more than two sets of chromosomes. Polyploidization results from cytokinesis failure that takes place progressively during the course of postnatal development. The proportion of polyploidy also increases with the aging process or with cellular stress such as surgical resection, toxic stimulation, metabolic overload, or oxidative damage, to involve as much as 90% of the hepatocytes in mice and 40% in humans. Hepatocyte polyploidization is generally considered an indicator of terminal differentiation and cellular senescence, and related to the dysfunction of insulin and p53/p21 signaling pathways. Interestingly, the high prevalence of hepatocyte polyploidization in the aged mouse liver can be reversed when the senescent hepatocytes are serially transplanted into young mouse livers. Here we review the current knowledge on the mechanism of hepatocytes polyploidization during postnatal growth, aging, and liver diseases. The biologic significance of polyploidization in senescent reversal, within the context of new ways to think of liver aging and liver diseases is considered.

  3. Integrin-linked kinase is involved in matrix-induced hepatocyte differentiation

    International Nuclear Information System (INIS)

    Gkretsi, Vasiliki; Bowen, William C.; Yang, Yu; Wu, Chuanyue; Michalopoulos, George K.

    2007-01-01

    Hepatocytes have restricted proliferative capacity in culture and when cultured without matrix, lose the hepatocyte-specific gene expression and characteristic cellular micro-architecture. Overlay of matrix-preparations on de-differentiated hepatocytes restores differentiation. Integrin-linked kinase (ILK) is a cell-matrix-adhesion protein crucial in fundamental processes such as differentiation and survival. In this study, we investigated the role of ILK, and its binding partners PINCH, α-parvin, and Mig-2 in matrix-induced hepatocyte differentiation. We report here that ILK is present in the liver and localizes at cell-matrix adhesions of cultured hepatocytes. We also show that ILK, PINCH, α-parvin, and Mig-2 expression level is dramatically reduced in the re-differentiated hepatocytes. Interestingly, hepatocytes lacking ILK undergo matrix-induced differentiation but their differentiation is incomplete, as judged by monitoring cell morphology and production of albumin. Our results show that ILK and cell-matrix adhesion proteins play an important role in the process of matrix-induced hepatocyte differentiation

  4. A new splice variant of the major subunit of human asialoglycoprotein receptor encodes a secreted form in hepatocytes.

    Directory of Open Access Journals (Sweden)

    Jia Liu

    Full Text Available BACKGROUND: The human asialoglycoprotein receptor (ASGPR is composed of two polypeptides, designated H1 and H2. While variants of H2 have been known for decades, the existence of H1 variants has never been reported. PRINCIPAL FINDINGS: We identified two splice variants of ASGPR H1 transcripts, designated H1a and H1b, in human liver tissues and hepatoma cells. Molecular cloning of ASGPR H1 variants revealed that they differ by a 117 nucleotide segment corresponding to exon 2 in the ASGPR genomic sequence. Thus, ASGPR variant H1b transcript encodes a protein lacking the transmembrane domain. Using an H1b-specific antibody, H1b protein and a functional soluble ASGPR (sASGPR composed of H1b and H2 in human sera and in hepatoma cell culture supernatant were identified. The expression of ASGPR H1a and H1b in Hela cells demonstrated the different cellular loctions of H1a and H1b proteins at cellular membranes and in intracellular compartments, respectively. In vitro binding assays using fluorescence-labeled sASGPR or the substract ASOR revealed that the presence of sASGPR reduced the binding of ASOR to cells. However, ASOR itself was able to enhance the binding of sASGPR to cells expressing membrane-bound ASGPR. Further, H1b expression is reduced in liver tissues from patients with viral hepatitis. CONCLUSIONS: We conclude that two naturally occurring ASGPR H1 splice variants are produced in human hepatocytes. A hetero-oligomeric complex sASGPR consists of the secreted form of H1 and H2 and may bind to free substrates in circulation and carry them to liver tissue for uptake by ASGPR-expressing hepatocytes.

  5. 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.

  6. Polyploidization delay in rat hepatocytes under liver growth inhibition by hypokinesia

    Science.gov (United States)

    Faktor, V. M.; Malyutin, V. F.; Li, S. Y.; Brodskiy, V. Y.

    1981-01-01

    A study of young rats, weighing 55 to 59 g, after being for 10 days in conditions of limited mobility, shows a retardation of body growth as well as that of liver growth. The decrease in the rate of growth is accompanied by a reduction of cell proliferation and by delay polyploidization of hepatocytes in the liver of experimental rats. The materials, methods, and results of research are discussed.

  7. Long-term culture and expansion of primary human hepatocytes

    NARCIS (Netherlands)

    Levy, G.; Bomze, D.; Heinz, S.; Ramachandran, S.D.; Noerenberg, A.; Cohen, M.; Shibolet, O.; Sklan, E.; Braspenning, J.C.; Nahmias, Y.

    2015-01-01

    Hepatocytes have a critical role in metabolism, but their study is limited by the inability to expand primary hepatocytes in vitro while maintaining proliferative capacity and metabolic function. Here we describe the oncostatin M (OSM)-dependent expansion of primary human hepatocytes by low

  8. Artificial fish schools : Collective effects of school size, body size, and body form

    NARCIS (Netherlands)

    Kunz, H.; Hemelrijk, C.K.

    2003-01-01

    Individual-based models of schooling in fish have demonstrated that, via processes of self-organization. artificial fish may school in the absence of a leader or external stimuli, using local information only. We study for the first time how body size and body form of artificial fish affect school

  9. Distinct neural mechanisms for body form and body motion discriminations

    NARCIS (Netherlands)

    Vangeneugden, Joris; Peelen, Marius V; Tadin, Duje; Battelli, Lorella

    2014-01-01

    Actions can be understood based on form cues (e.g., static body posture) as well as motion cues (e.g., gait patterns). A fundamental debate centers on the question of whether the functional and neural mechanisms processing these two types of cues are dissociable. Here, using fMRI, psychophysics, and

  10. The potential of induced pluripotent stem cell derived hepatocytes.

    Science.gov (United States)

    Hannoun, Zara; Steichen, Clara; Dianat, Noushin; Weber, Anne; Dubart-Kupperschmitt, Anne

    2016-07-01

    Orthotopic liver transplantation remains the only curative treatment for liver disease. However, the number of patients who die while on the waiting list (15%) has increased in recent years as a result of severe organ shortages; furthermore the incidence of liver disease is increasing worldwide. Clinical trials involving hepatocyte transplantation have provided encouraging results. However, transplanted cell function appears to often decline after several months, necessitating liver transplantation. The precise aetiology of the loss of cell function is not clear, but poor engraftment and immune-mediated loss appear to be important factors. Also, primary human hepatocytes (PHH) are not readily available, de-differentiate, and die rapidly in culture. Hepatocytes are available from other sources, such as tumour-derived human hepatocyte cell lines and immortalised human hepatocyte cell lines or porcine hepatocytes. However, all these cells suffer from various limitations such as reduced or differences in functions or risk of zoonotic infections. Due to their significant potential, one possible inexhaustible source of hepatocytes is through the directed differentiation of human induced pluripotent stem cells (hiPSCs). This review will discuss the potential applications and existing limitations of hiPSC-derived hepatocytes in regenerative medicine, drug screening, in vitro disease modelling and bioartificial livers. Copyright © 2016 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

  11. Metabolism of para-aminophenol by rat hepatocytes.

    Science.gov (United States)

    Yan, Z; Nikelly, J G; Killmer, L; Tarloff, J B

    2000-08-01

    Autoxidation of para-aminophenol (PAP) has been proposed to account for the selective nephrotoxicity of this compound. However, other studies suggest that hepatic metabolites of PAP rather than the parent compound may be responsible for renal damage. These studies were designed to investigate PAP metabolism in isolated hepatocytes. We synthesized several proposed metabolites for analysis by HPLC/mass spectrometry and compared those results with HPLC/mass spectrometric analyses of metabolites found after incubating hepatocytes with PAP. Hepatocytes prepared from male Sprague-Dawley rats were incubated in Krebs-Henseleit buffer at 37 degrees C for 5 h with 2.3 mM PAP under an atmosphere of 5% CO2/95% O2. Aliquots were withdrawn at 0.1 h of incubation and then hourly through 5 h of incubation. Reactions were terminated by the addition of acetonitrile. Hepatocyte viability was unaltered with PAP present in the incubation medium. We found that hepatocytes converted PAP to two major metabolites (PAP-GSH conjugates and PAP-N-acetylcysteine conjugates) and several minor metabolites [PAP-O-glucuronide, acetaminophen (APAP), APAP-O-glucuronide, APAP-GSH conjugates, and 4-hydroxyformanilide]. Preincubating hepatoyctes with 1-aminobenzotriazole, an inhibitor of cytochromes P450, did not alter the pattern of PAP metabolism. In conclusion, we found that PAP was metabolized in hepatocytes predominantly to PAP-GSH conjugates and PAP-N-acetylcysteine conjugates in sufficient quantities to account for the nephrotoxicity of PAP.

  12. Prolongation of liver-specific function for primary hepatocytes maintenance in 3D printed architectures.

    Science.gov (United States)

    Kim, Yohan; Kang, Kyojin; Yoon, Sangtae; Kim, Ji Sook; Park, Su A; Kim, Wan Doo; Lee, Seung Bum; Ryu, Ki-Young; Jeong, Jaemin; Choi, Dongho

    2018-01-23

    Isolated primary hepatocytes from the liver are very similar to in vivo native liver hepatocytes, but they have the disadvantage of a limited lifespan in 2D culture. Although a sandwich culture and 3D organoids with mesenchymal stem cells (MSCs) as an attractive assistant cell source to extend lifespan can be used, it cannot fully reproduce the in vivo architecture. Moreover, long-term 3D culture leads to cell death because of hypoxic stress. Therefore, to overcome the drawback of 2D and 3D organoids, we try to use a 3D printing technique using alginate hydrogels with primary hepatocytes and MSCs. The viability of isolated hepatocytes was more than 90%, and the cells remained alive for 7 days without morphological changes in the 3D hepatic architecture with MSCs. Compared to a 2D system, the expression level of functional hepatic genes and proteins was higher for up to 7 days in the 3D hepatic architecture. These results suggest that both the 3D bio-printing technique and paracrine molecules secreted by MSCs supported long-term culture of hepatocytes without morphological changes. Thus, this technique allows for widespread expansion of cells while forming multicellular aggregates, may be applied to drug screening and could be an efficient method for developing an artificial liver.

  13. Liver tissue engineering based on aggregate assembly: efficient formation of endothelialized rat hepatocyte aggregates and their immobilization with biodegradable fibres

    International Nuclear Information System (INIS)

    Pang, Y; Shinohara, M; Komori, K; Sakai, Y; Montagne, K

    2012-01-01

    To realize long-term in vitro culture of hepatocytes at a high density while maintaining a high hepatic function for aggregate-based liver tissue engineering, we report here a novel culture method whereby endothelialized rat hepatocyte aggregates were formed using a PDMS microwell device and cultured in a perfusion bioreactor by introducing spacers between aggregates to improve oxygen and nutrient supply. Primary rat hepatocyte aggregates around 100 µm in diameter coated with human umbilical vein endothelial cells were spontaneously and quickly formed after 12 h of incubation, thanks to the continuous supply of oxygen by diffusion through the PDMS honeycomb microwell device. Then, the recovered endothelialized rat hepatocyte aggregates were mixed with biodegradable poly-l-lactic acid fibres in suspension and packed into a PDMS-based bioreactor. Perfusion culture of 7 days was successfully achieved with more than 73.8% cells retained in the bioreactor. As expected, the fibres acted as spacers between aggregates, which was evidenced from the enhanced albumin production and more spherical morphology compared with fibre-free packing. In summary, this study shows the advantages of using PDMS-based microwells to form heterotypic aggregates and also demonstrates the feasibility of spacing tissue elements for improving oxygen and nutrient supply to tissue engineering based on modular assembly. (paper)

  14. Water and nonelectrolyte permeability of isolated rat hepatocytes

    International Nuclear Information System (INIS)

    Alpini, G.; Garrick, R.A.; Jones, M.J.; Nunes, R.; Tavoloni, N.

    1986-01-01

    We have measured the diffusive permeability coefficients of isolated rat hepatocytes to 3 H 2 O, [ 14 C]urea, [ 14 C]erythritol, [ 14 C]mannitol, [ 3 H]sucrose, and [ 3 H]inulin, employing a technique previously developed for erythrocytes (Redwood et al., J. Gen. Physiol 64:706-729, 1974). Diffusion coefficients for the tracer molecules were measured in packed hepatocytes, supernatant fluid, and intracellular medium (lysed hepatocytes) and were calculated assuming one-dimensional semi-infinite diffusion through a homogeneous medium. By applying the series-parallel pathway model, the following permeability coefficients (10(-5) cm/sec) for the hepatocyte plasma membrane were obtained. 3 H 2 O, 98.6 +/- 18.4; [ 14 C]urea, 18.2 +/- 5.3; [ 14 C]erythritol, 4.8 +/- 1.6; [ 14 C]mannitol, 3.1 +/- 1.4; [ 3 H]sucrose, 0; [ 3 H]inulin, 0. These results indicate that isolated rat hepatocytes are highly permeable to water and polar nonelectrolytes, when compared with other transporting epithelia. This relatively high cellular permeability is consistent with a model in which nonelectrolyte permeation is via an aqueous pathway of equivalent pore diameter of 8-12 A. The finding that [ 14 C]erythritol and [ 14 C]mannitol cross the hepatocyte plasma membrane indicates that these molecules enter the bile canaliculus through the transcellular route. Conversely, the failure of [ 3 H]sucrose and [ 3 H]inulin to permeate the hepatocyte in the isolated condition supports the concept that biliary entry of these large carbohydrates, at least that fraction which cannot be accounted for by a vesicular mechanism, must occur via the transjunctional shunt pathway

  15. 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.

  16. Inhibition of hepatocyte gap junctional intercellular communication by tumor promoters

    International Nuclear Information System (INIS)

    Ruch, R.J.

    1988-01-01

    The mechanisms by which tumor promoters enhance neoplasia are poorly understood. One effect common to most tumor promoters is their ability to inhibit the cell-to-cell exchange of small molecules and ions through gap junctions, i.e., gap junctional intercellular communication (IC). IC maybe necessary for normal growth control and the loss of IC may predispose cells to enhanced growth. In the present studies, the effects of liver tumor promoters and other agents on IC between rodent hepatocytes in primary culture has been studied. IC was detected between hepatocytes: (1) autoradiographically following the passage and incorporation of [5- 3 H]uridine nucleotides from pre-labeled donor hepatocytes to non-labeled, adjacent recipient hepatocytes and (2) by fluorescence microscopy after microinjection of fluorescent Lucifer Yellow CH dye into hepatocytes and visualizing dye spread into adjacent hepatocytes

  17. Hepatocyte membrane injury and bleb formation following low dose comfrey toxicity in rats.

    Science.gov (United States)

    Yeong, M L; Wakefield, S J; Ford, H C

    1993-04-01

    Comfrey, a popular herbal remedy, contains hepatotoxic pyrrolizidine alkaloids and has been implicated in recent human toxicity. Although alkaloids from other plant sources have been extensively researched, studies on the hepatotoxic effects of comfrey alkaloids are scant. The effects of high dose comfrey toxicity have been studied and the present investigation was undertaken to identify changes associated with relatively low dose toxicity. Eight young adult rats were dosed weekly for six weeks with 50 mg/kg of comfrey derived alkaloids. The animals were dissected one week after the last dose and the livers examined by light and electron microscopy. Changes at the light microscopic level showed vascular congestion, mild zone 3 necrosis and loss of definition of hepatocyte cellular membranes. Extensive ultrastructural abnormalities were identified in the form of endothelial sloughing and the loss of hepatocyte microvilli. A striking finding was florid bleb formation on the sinusoidal borders of hepatocytes. Many blebs were shed into the space of Disse and extruded to fill, and sometimes occlude, sinusoidal lumina. Platelets were frequently found in areas of bleb formation. There was evidence of late damage in collagenization of Disse's space. Hepatocyte bleb formation is known to occur under a variety of pathological conditions but there is little to no information in the literature on the effects, if any, of bleb formation on fibrogenesis and the microcirculation and its role in the pathogenesis of liver disease. The pyrrolizidine alkaloids of comfrey may serve as an experimental tool to study the process of bleb formation and the intimate relationship between hepatocyte and sinusoidal injury in the liver.

  18. Intracellular cholesterol-binding proteins enhance HDL-mediated cholesterol uptake in cultured primary mouse hepatocytes.

    Science.gov (United States)

    Storey, Stephen M; McIntosh, Avery L; Huang, Huan; Landrock, Kerstin K; Martin, Gregory G; Landrock, Danilo; Payne, H Ross; Atshaves, Barbara P; Kier, Ann B; Schroeder, Friedhelm

    2012-04-15

    A major gap in our knowledge of rapid hepatic HDL cholesterol clearance is the role of key intracellular factors that influence this process. Although the reverse cholesterol transport pathway targets HDL to the liver for net elimination of free cholesterol from the body, molecular details governing cholesterol uptake into hepatocytes are not completely understood. Therefore, the effects of sterol carrier protein (SCP)-2 and liver fatty acid-binding protein (L-FABP), high-affinity cholesterol-binding proteins present in hepatocyte cytosol, on HDL-mediated free cholesterol uptake were examined using gene-targeted mouse models, cultured primary hepatocytes, and 22-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)-amino]-23,24-bisnor-5-cholen-3β-ol (NBD-cholesterol). While SCP-2 overexpression enhanced NBD-cholesterol uptake, counterintuitively, SCP-2/SCP-x gene ablation also 1) enhanced the rapid molecular phase of free sterol uptake detectable in rate and maximal uptake of HDL free cholesterol and 2) differentially enhanced free cholesterol uptake mediated by the HDL3, rather than the HDL2, subfraction. The increased HDL free cholesterol uptake was not due to increased expression or distribution of the HDL receptor [scavenger receptor B1 (SRB1)], proteins regulating SRB1 [postsynaptic density protein (PSD-95)/Drosophila disk large tumor suppressor (dlg)/tight junction protein (ZO1) and 17-kDa membrane-associated protein], or other intracellular cholesterol trafficking proteins (steroidogenic acute response protein D, Niemann Pick C, and oxysterol-binding protein-related proteins). However, expression of L-FABP, the single most prevalent hepatic cytosolic protein that binds cholesterol, was upregulated twofold in SCP-2/SCP-x null hepatocytes. Double-immunogold electron microscopy detected L-FABP sufficiently close to SRB1 for direct interaction, similar to SCP-2. These data suggest a role for L-FABP in HDL cholesterol uptake, a finding confirmed with SCP-2/SCP-x/L-FABP null

  19. Property of hepatitis B virus replication in Tupaia belangeri hepatocytes

    International Nuclear Information System (INIS)

    Sanada, Takahiro; Tsukiyama-Kohara, Kyoko; Yamamoto, Naoki; Ezzikouri, Sayeh; Benjelloun, Soumaya; Murakami, Shuko; Tanaka, Yasuhito; Tateno, Chise; Kohara, Michinori

    2016-01-01

    The northern treeshrew (Tupaia belangeri) has been reported to be an effective candidate for animal infection model with hepatitis B virus (HBV). The objective of our study was to analyze the growth characteristics of HBV in tupaia hepatocytes and the host response to HBV infection. We established primary tupaia hepatocytes (3–6-week old tupaia) and infected them with HBV genotypes A, B and C, and all the genotypes proliferated as well as those in human primary hepatocytes (>10"5 copies/ml in culture supernatant). We next generated a chimeric mouse with tupaia liver by transplantation of tupaia primary hepatocytes to urokinase-type plasminogen activator cDNA (cDNA-uPA)/severe combined immunodeficient (SCID) mice and the replacement ratio with tupaia hepatocytes was found to be more than 95%. Infection of chimeric mice with HBV (genotypes B, C, and D) resulted in HBV-DNA level of 10"4-10"6 copies/ml after 8 weeks of infection, which were almost similar to that in humanized chimeric mouse. In contrast, serum HBV level in adult tupaia (1-year-old tupaia) was quite low (<10"3 copies/ml). Understanding the differences in the response to HBV infection in primary tupaia hepatocytes, chimeric mouse, and adult tupaia will contribute to elucidating the mechanism of persistent HBV infection and viral eradication. Thus, T. belangeri was found to be efficient for studying the host response to HBV infection, thereby providing novel insight into the pathogenesis of HBV. - Highlights: • Primary hepatocytes were established from tupaia that is a novel HBV infection model. • Tupaia primary hepatocytes were susceptible for HBV infection. • The immunodeficient chimeric mice with tupaia hepatocytes were established. • The chimeric mice with tupaia hepatocytes were susceptible for HBV infection.

  20. Property of hepatitis B virus replication in Tupaia belangeri hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Sanada, Takahiro [Department of Microbiology and Cell Biology, Tokyo Metropolitan Institute of Medical Science, 2-1-6, Kamikitazawa, Setagaya-ku, Tokyo 156-8506 (Japan); Tsukiyama-Kohara, Kyoko, E-mail: kkohara@vet.kagoshima-u.ac.jp [Transboundary Animal Diseases Centre, Joint Faculty of Veterinary Medicine, Kagoshima University, 1-21-24, Korimoto, Kagoshima-city, Kagoshima 890-0065 (Japan); Laboratory of Animal Hygiene, Joint Faculty of Veterinary Medicine, Kagoshima University, 1-21-24, Korimoto, Kagoshima, Kagoshima 890-0065 (Japan); Yamamoto, Naoki [Department of Microbiology and Cell Biology, Tokyo Metropolitan Institute of Medical Science, 2-1-6, Kamikitazawa, Setagaya-ku, Tokyo 156-8506 (Japan); Ezzikouri, Sayeh; Benjelloun, Soumaya [Viral Hepatitis Laboratory, Virology Unit, Institut Pasteur du Maroc, 1, Louis Pasteur, Casablanca 20360 (Morocco); Murakami, Shuko; Tanaka, Yasuhito [Department of Virology and Liver Unit, Nagoya City University Graduate School of Medical Sciences, Kawasumi 1, Mizuho-ku, Nagoya, Aichi 467-8601 (Japan); Tateno, Chise [PhoenixBio Co. Ltd., 3-4-1, Kagamiyama, Higashi-Hiroshima, Hiroshima 739-0046 (Japan); Kohara, Michinori, E-mail: kohara-mc@igakuken.or.jp [Department of Microbiology and Cell Biology, Tokyo Metropolitan Institute of Medical Science, 2-1-6, Kamikitazawa, Setagaya-ku, Tokyo 156-8506 (Japan)

    2016-01-08

    The northern treeshrew (Tupaia belangeri) has been reported to be an effective candidate for animal infection model with hepatitis B virus (HBV). The objective of our study was to analyze the growth characteristics of HBV in tupaia hepatocytes and the host response to HBV infection. We established primary tupaia hepatocytes (3–6-week old tupaia) and infected them with HBV genotypes A, B and C, and all the genotypes proliferated as well as those in human primary hepatocytes (>10{sup 5} copies/ml in culture supernatant). We next generated a chimeric mouse with tupaia liver by transplantation of tupaia primary hepatocytes to urokinase-type plasminogen activator cDNA (cDNA-uPA)/severe combined immunodeficient (SCID) mice and the replacement ratio with tupaia hepatocytes was found to be more than 95%. Infection of chimeric mice with HBV (genotypes B, C, and D) resulted in HBV-DNA level of 10{sup 4}-10{sup 6} copies/ml after 8 weeks of infection, which were almost similar to that in humanized chimeric mouse. In contrast, serum HBV level in adult tupaia (1-year-old tupaia) was quite low (<10{sup 3} copies/ml). Understanding the differences in the response to HBV infection in primary tupaia hepatocytes, chimeric mouse, and adult tupaia will contribute to elucidating the mechanism of persistent HBV infection and viral eradication. Thus, T. belangeri was found to be efficient for studying the host response to HBV infection, thereby providing novel insight into the pathogenesis of HBV. - Highlights: • Primary hepatocytes were established from tupaia that is a novel HBV infection model. • Tupaia primary hepatocytes were susceptible for HBV infection. • The immunodeficient chimeric mice with tupaia hepatocytes were established. • The chimeric mice with tupaia hepatocytes were susceptible for HBV infection.

  1. Cholesterol crystallization within hepatocyte lipid droplets and its role in murine NASH.

    Science.gov (United States)

    Ioannou, George N; Subramanian, Savitha; Chait, Alan; Haigh, W Geoffrey; Yeh, Matthew M; Farrell, Geoffrey C; Lee, Sum P; Savard, Christopher

    2017-06-01

    We recently reported that cholesterol crystals form in hepatocyte lipid droplets (LDs) in human and experimental nonalcoholic steatohepatitis. Herein, we assigned WT C57BL/6J mice to a high-fat (15%) diet for 6 months, supplemented with 0%, 0.25%, 0.5%, 0.75%, or 1% dietary cholesterol. Increasing dietary cholesterol led to cholesterol loading of the liver, but not of adipose tissue, resulting in fibrosing steatohepatitis at a dietary cholesterol concentration of ≥0.5%, whereas mice on lower-cholesterol diets developed only simple steatosis. Hepatic cholesterol crystals and crown-like structures also developed at a dietary cholesterol concentration ≥0.5%. Crown-like structures consisted of activated Kupffer cells (KCs) staining positive for NLRP3 and activated caspase 1, which surrounded and processed cholesterol crystal-containing remnant LDs of dead hepatocytes. The KCs processed LDs at the center of crown-like structures in the extracellular space by lysosomal enzymes, ultimately transforming into lipid-laden foam cells. When HepG2 cells were exposed to LDL cholesterol, they developed cholesterol crystals in LD membranes, which caused activation of THP1 cells (macrophages) grown in coculture; upregulation of TNF-alpha , NLRP3, and interleukin 1beta ( IL1β ) mRNA; and secretion of IL-1beta. In conclusion, cholesterol crystals form on the LD membrane of hepatocytes and cause activation and cholesterol loading of KCs that surround and process these LDs by lysosomal enzymes.

  2. Hyperinsulinemia is associated with increased soluble insulin receptors release from hepatocytes

    Directory of Open Access Journals (Sweden)

    Marcia eHiriart

    2014-06-01

    Full Text Available It has been generally assumed that insulin circulates freely in blood. However it can also interact with plasma proteins. Insulin receptors are located in the membrane of target cells and consist of an alpha and beta subunits with a tyrosine kinase cytoplasmic domain. The ectodomain, called soluble insulin receptor (SIR has been found elevated in patients with diabetes mellitus. We explored if insulin binds to SIRs in circulation under physiological conditions and hypothesize that this SIR may be released by hepatocytes in response to high insulin concentrations. The presence of SIR in rat and human plasmas and the culture medium of hepatocytes was explored using Western blot analysis. A purification protocol was performed to isolated SIR using affinity, gel filtration and ion exchange chromatographies. A modified reverse hemolytic plaque assay was used to measure SIR release from cultured hepatocytes. Incubation with 1 nmol l-1 insulin induces the release of the insulin receptor ectodomains from normal rat hepatocytes. This effect can be partially prevented by blocking protease activity. Furthermore, plasma levels of SIR were higher in a model of metabolic syndrome, where rats are hyperinsulinemic. We also found increased SIR levels in hyperinsulinemic humans. SIR may be an important regulator of the amount of free insulin in circulation. In hyperinsulinemia the amount of this soluble receptor increases, this could lead to higher amounts of insulin bound to this receptor, rather than free insulin, which is the biologically active form of the hormone. This observation could enlighten the mechanisms of insulin resistance.

  3. The homeobox gene Hex regulates hepatocyte differentiation from embryonic stem cell-derived endoderm.

    Science.gov (United States)

    Kubo, Atsushi; Kim, Yon Hui; Irion, Stefan; Kasuda, Shogo; Takeuchi, Mitsuaki; Ohashi, Kazuo; Iwano, Masayuki; Dohi, Yoshiko; Saito, Yoshihiko; Snodgrass, Ralph; Keller, Gordon

    2010-02-01

    We investigated the role of the hematopoietically expressed homeobox (Hex) in the differentiation and development of hepatocytes within embryonic stem cell (ESC)-derived embryoid bodies (EBs). Analyses of hepatic endoderm derived from Hex(-/-) EBs revealed a dramatic reduction in the levels of albumin (Alb) and alpha-fetoprotein (Afp) expression. In contrast, stage-specific forced expression of Hex in EBs from wild-type ESCs led to the up-regulation of Alb and Afp expression and secretion of Alb and transferrin. These inductive effects were restricted to c-kit(+) endoderm-enriched EB-derived populations, suggesting that Hex functions at the level of hepatic specification of endoderm in this model. Microarray analysis revealed that Hex regulated the expression of a broad spectrum of hepatocyte-related genes, including fibrinogens, apolipoproteins, and cytochromes. When added to the endoderm-induced EBs, bone morphogenetic protein 4 acted synergistically with Hex in the induction of expression of Alb, Afp, carbamoyl phosphate synthetase, transcription factor 1, and CCAAT/enhancer binding protein alpha. These findings indicate that Hex plays a pivotal role during induction of liver development from endoderm in this in vitro model and suggest that this strategy may provide important insight into the generation of functional hepatocytes from ESCs.

  4. Functional assessment of hepatocytes after transplantation into rat spleen

    International Nuclear Information System (INIS)

    Woods, R.J.; Fuller, B.J.; Attenburrow, V.D.; Nutt, L.H.; Hobbs, K.E.

    1982-01-01

    The retention of structural integrity and metabolic function by isolated hepatocytes after ectopic transplantation has been investigated in autografted rats. Rats were partially hepatectomized and isolated hepatocytes prepared from the excised liver lobes were implanted into their spleens. Histological examination of the spleens 7 or more weeks after implantation revealed aggregates of hepatocytes in the red pulp. Two tests of biochemical function were applied to the hepatocytes after transplantation. In the first the hepatobiliary imaging agent technetium-99m N-[N'-(2, 6-dimethylphenyl)carbamoylmethyl]iminodiacetic acid (99mTc HIDA), which was shown to be avidly taken up by isolated hepatocytes in vitro, was infused into the tail veins of autograft and control rats. Radioactivity accumulating in the spleens of autografted rats was markedly greater than that in controls implanted with lethally damaged cells or in nontransplanted rats. In the second the presence of bilirubin metabolites was sought in autograft spleens after intravenous infusion of bilirubin. Both mono- and diglucuronides of bilirubin were recovered from the spleens of autograft rats but no conjugates were recovered from the spleens of unoperated controls. We conclude that after autotransplantation isolated hepatocytes retain their morphology and at least some of their functional activities

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    Lifescience Database Archive (English)

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  9. Billion-scale production of hepatocyte-like cells from human induced pluripotent stem cells.

    Science.gov (United States)

    Yamashita, Tomoki; Takayama, Kazuo; Sakurai, Fuminori; Mizuguchi, Hiroyuki

    2018-02-19

    Human induced pluripotent stem (iPS) cell-derived hepatocyte-like cells are expected to be utilized in drug screening and regenerative medicine. However, hepatocyte-like cells have not been fully used in such applications because it is difficult to produce such cells on a large scale. In this study, we tried to establish a method to mass produce hepatocyte-like cells using a three-dimensional (3D) cell culture bioreactor called the Rotary Cell Culture System (RCCS). RCCS enabled us to obtain homogenous hepatocyte-like cells on a billion scale (>10 9  cells). The gene expression levels of some hepatocyte markers (alpha-1 antitrypsin, cytochrome (CYP) 1A2, CYP2D6, and hepatocyte nuclear factor 4alpha) were higher in 3D-cultured hepatocyte-like cells than in 2D-cultured hepatocyte-like cells. This result suggests that RCCS could provide more suitable conditions for hepatocyte maturation than the conventional 2D cell culture conditions. In addition, more than 90% of hepatocyte-like cells were positive for albumin and could uptake low-density lipoprotein in the culture medium. We succeeded in the large-scale production of homogenous and functional hepatocyte-like cells from human iPS cells. This technology will be useful in drug screening and regenerative medicine, which require enormous numbers of hepatocyte-like cells. Copyright © 2018 Elsevier Inc. All rights reserved.

  10. Form or function: Does focusing on body functionality protect women from body dissatisfaction when viewing media images?

    Science.gov (United States)

    Mulgrew, Kate E; Tiggemann, Marika

    2018-01-01

    We examined whether shifting young women's ( N =322) attention toward functionality components of media-portrayed idealized images would protect against body dissatisfaction. Image type was manipulated via images of models in either an objectified body-as-object form or active body-as-process form; viewing focus was manipulated via questions about the appearance or functionality of the models. Social comparison was examined as a moderator. Negative outcomes were most pronounced within the process-related conditions (body-as-process images or functionality viewing focus) and for women who reported greater functionality comparison. Results suggest that functionality-based depictions, reflections, and comparisons may actually produce worse outcomes than those based on appearance.

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  14. File list: ALL.Liv.10.AllAg.Hepatocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  15. File list: Pol.Liv.05.AllAg.Hepatocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  16. File list: ALL.Liv.50.AllAg.Hepatocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  17. File list: Pol.Liv.10.AllAg.Hepatocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  18. Role of macrophages in the immune response to hepatocytes

    International Nuclear Information System (INIS)

    Bumgardner, G.L.; Chen, S.; Almond, S.P.; Ascher, N.L.; Payne, W.D.; Matas, A.J.

    1990-01-01

    The purpose of this study was to determine the role of host macrophages in the development of allospecific cytolytic T cells (allo-CTLs) in response to purified allogeneic MHC Class I+, Class II- hepatocytes in vivo in hepatocyte sponge matrix allografts (HC-SMA). Depletion of antigen-presenting cells (APCs) from responder splenocytes in mixed lymphocyte hepatocyte culture (MLHC) inhibits the development of allo-CTLs in response to purified hepatocytes. First the ability of sponge macrophages to function as accessory cells in indirect presentation of hepatocyte Class I antigen was tested in MLHC. We found that addition of irradiated sponge cells (a source of sponge macrophages) restored the development of allo-CTLs in MLHC depleted of responder APCs. Therefore, radioresistant sponge macrophages can function as accessory cells in MLHC. We next employed silica as an immunotherapy targeted against host macrophages and assessed the effect on development of allo-CTLs in HC-SMA. We found that local (intrasponge) silica treatment completely inhibited the development of allo-CTLs in HC-SMA. Combined local and systemic silica treatment resulted in inhibition of allocytotoxicity comparable to local silica treatment alone in the doses tested. We conclude that host macrophages which infiltrate HC-SMA can function as accessory cells in vitro in MLHC and that both infiltrating host macrophages and lymphocytes participate in the development of an alloimmune response to purified hepatocytes in vivo. This interaction may involve indirect antigen presentation of hepatocyte Class I antigen by macrophages to host lymphocytes which accumulate in HC-SMA

  19. File list: His.Liv.10.AllAg.Hepatocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  20. File list: ALL.Liv.50.AllAg.Hepatocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  1. High throughput micro-well generation of hepatocyte micro-aggregates for tissue engineering.

    Directory of Open Access Journals (Sweden)

    Elien Gevaert

    Full Text Available The main challenge in hepatic tissue engineering is the fast dedifferentiation of primary hepatocytes in vitro. One successful approach to maintain hepatocyte phenotype on the longer term is the cultivation of cells as aggregates. This paper demonstrates the use of an agarose micro-well chip for the high throughput generation of hepatocyte aggregates, uniform in size. In our study we observed that aggregation of hepatocytes had a beneficial effect on the expression of certain hepatocyte specific markers. Moreover we observed that the beneficial effect was dependent on the aggregate dimensions, indicating that aggregate parameters should be carefully considered. In a second part of the study, the selected aggregates were immobilized by encapsulation in methacrylamide-modified gelatin. Phenotype evaluations revealed that a stable hepatocyte phenotype could be maintained during 21 days when encapsulated in the hydrogel. In conclusion we have demonstrated the beneficial use of micro-well chips for hepatocyte aggregation and the size-dependent effects on hepatocyte phenotype. We also pointed out that methacrylamide-modified gelatin is suitable for the encapsulation of these aggregates.

  2. High throughput micro-well generation of hepatocyte micro-aggregates for tissue engineering.

    Science.gov (United States)

    Gevaert, Elien; Dollé, Laurent; Billiet, Thomas; Dubruel, Peter; van Grunsven, Leo; van Apeldoorn, Aart; Cornelissen, Ria

    2014-01-01

    The main challenge in hepatic tissue engineering is the fast dedifferentiation of primary hepatocytes in vitro. One successful approach to maintain hepatocyte phenotype on the longer term is the cultivation of cells as aggregates. This paper demonstrates the use of an agarose micro-well chip for the high throughput generation of hepatocyte aggregates, uniform in size. In our study we observed that aggregation of hepatocytes had a beneficial effect on the expression of certain hepatocyte specific markers. Moreover we observed that the beneficial effect was dependent on the aggregate dimensions, indicating that aggregate parameters should be carefully considered. In a second part of the study, the selected aggregates were immobilized by encapsulation in methacrylamide-modified gelatin. Phenotype evaluations revealed that a stable hepatocyte phenotype could be maintained during 21 days when encapsulated in the hydrogel. In conclusion we have demonstrated the beneficial use of micro-well chips for hepatocyte aggregation and the size-dependent effects on hepatocyte phenotype. We also pointed out that methacrylamide-modified gelatin is suitable for the encapsulation of these aggregates.

  3. Hepatocyte and keratinocyte growth factors and their receptors in human lung emphysema

    Directory of Open Access Journals (Sweden)

    Marchal Joëlle

    2005-10-01

    Full Text Available Abstract Background Hepatocyte and keratinocyte growth factors are key growth factors in the process of alveolar repair. We hypothesized that excessive alveolar destruction observed in lung emphysema involves impaired expression of hepatocyte and keratinocyte growth factors or their respective receptors, c-met and keratinocyte growth factor receptor. The aim of our study was to compare the expression of hepatocyte and keratinocyte growth factors and their receptors in lung samples from 3 groups of patients: emphysema; smokers without emphysema and non-smokers without emphysema. Methods Hepatocyte and keratinocyte growth factor proteins were analysed by immunoassay and western blot; mRNA expression was measured by real time quantitative polymerase chain reaction. Results Hepatocyte and keratinocyte growth factors, c-met and keratinocyte growth factor receptor mRNA levels were similar in emphysema and non-emphysema patients. Hepatocyte growth factor mRNA correlated negatively with FEV1 and the FEV1/FVC ratio both in emphysema patients and in smokers with or without emphysema. Hepatocyte and keratinocyte growth factor protein concentrations were similar in all patients' groups. Conclusion The expression of hepatocyte and keratinocyte growth factors and their receptors is preserved in patients with lung emphysema as compared to patients without emphysema. Hepatocyte growth factor mRNA correlates with the severity of airflow obstruction in smokers.

  4. File list: ALL.Liv.20.AllAg.Hepatocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  5. File list: ALL.Liv.05.AllAg.Hepatocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  6. File list: ALL.Liv.10.AllAg.Hepatocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  7. What women like: influence of motion and form on esthetic body perception

    Directory of Open Access Journals (Sweden)

    Valentina eCazzato

    2012-07-01

    Full Text Available Several studies have shown the distinct contribution of motion and form to the esthetic evaluation of female bodies. Here, we investigated how variations of implied motion and body size interact in the esthetic evaluation of female and male bodies in a sample of young healthy women. Participants provided attractiveness, beauty, and liking ratings for the shape and posture of virtual renderings of human bodies with variable body size and implied motion. The esthetic judgments for both shape and posture of human models were influenced by body size and implied motion, with a preference for thinner and more dynamic stimuli. Implied motion, however, attenuated the impact of extreme body size on the esthetic evaluation of body postures, and body size variations did not affect the preference for more dynamic stimuli. Results show that body form and action cues interact in esthetic perception, but the final esthetic appreciation of human bodies is predicted by a mixture of perceptual and affective evaluative components.

  8. Gel entrapment culture of rat hepatocytes for investigation of tetracycline-induced toxicity

    International Nuclear Information System (INIS)

    Shen Chong; Meng Qin; Schmelzer, Eva; Bader, Augustinus

    2009-01-01

    This paper aimed to explore three-dimensionally cultured hepatocytes for testing drug-induced nonalcoholic steatohepatitis. Gel entrapped rat hepatocytes were applied for investigation of the tetracycline-induced steatohepatitis, while hepatocyte monolayer was set as a control. The toxic responses of hepatocytes were systematically evaluated by measuring cell viability, liver-specific function, lipid accumulation, oxidative stress, adenosine triphosphate content and mitochondrial membrane potential. The results suggested that gel entrapped hepatocytes showed cell death after 96 h of tetracycline treatment at 25 μM which is equivalent to toxic serum concentration in rats, while hepatocyte monolayer showed cell death at a high dose of 200 μM. The concentration-dependent accumulation of lipid as well as mitochondrial damage were regarded as two early events for tetracycline hepatotoxicity in gel entrapment culture due to their detectability ahead of subsequent increase of oxidative stress and a final cell death. Furthermore, the potent protection of fenofibrate and fructose-1,6-diphosphate were evidenced in only gel entrapment culture with higher expressions on the genes related to β-oxidation than hepatocyte monolayer, suggesting the mediation of lipid metabolism and mitochondrial damage in tetracycline toxicity. Overall, gel entrapped hepatocytes in three-dimension reflected more of the tetracycline toxicity in vivo than hepatocyte monolayer and thus was suggested as a more relevant system for evaluating steatogenic drugs.

  9. Hepatitis C virus core protein expression leads to biphasic regulation of the p21 cdk inhibitor and modulation of hepatocyte cell cycle

    International Nuclear Information System (INIS)

    Nguyen, Hau; Mudryj, Maria; Guadalupe, Moraima; Dandekar, Satya

    2003-01-01

    Hepatitis C virus (HCV) Core protein is implicated in viral pathogenesis by the modulation of hepatocyte gene expression and function. To determine the effect of Core protein on the cell-cycle control of hepatocytes, a HepG2 cell line containing a Flag-tagged Core under the control of an inducible promoter was generated. Initial Core protein expression included the presence of unprocessed (191 aa) and processed (173 aa) forms of the Core proteins with the processed form becoming dominant later. Expression of the 191 aa form of Core protein corresponded to an increase in the expression of the p21, a decrease in cdk2-dependent kinase activity, and a decrease in the percentage of cells in S-phase along with an accumulation of cells in the G 0 /G 1 phase of the cell cycle. As the processed form accumulated, the p21 levels started to decline, suggesting that Core protein regulates p21 expression in a biphasic manner. These findings implicate Core protein in potentially modulating hepatocyte cell cycle differentially in the early stages of infection through biphasic regulation of p21 cdk kinase inhibitor

  10. File list: Oth.Liv.50.AllAg.Hepatocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  11. File list: Oth.Liv.20.AllAg.Hepatocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  12. File list: Oth.Liv.05.AllAg.Hepatocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  13. Effects of edaravone, a radical scavenger, on hepatocyte transplantation.

    Science.gov (United States)

    Hayashi, Chihiro; Ito, Masahiro; Ito, Ryoutaro; Murakumo, Akiko; Yamamoto, Naoki; Hiramatsu, Noriko; Fox, Ira J; Horiguchi, Akihiko

    2014-12-01

    Hepatocyte transplantation (HTx) has yielded significant improvements in liver function and survival in experimentally induced acute liver failure and liver-based metabolic disease. However, transplantation is inefficient, and it is thought that transplanted hepatocytes have a shortened lifespan because of inflammation involving excess nitric oxide (NO). The present study aimed to clarify whether edaravone, a free radical scavenger used to treat ischemic stroke, could reduce ischemic changes in hepatocyte-transplanted livers. Edaravone (3 mg/kg) was administered intravenously 24 h before HTx to Nagase analbuminemic rats (NARs). Hepatocytes were isolated, and 30 × 10(6) cells were injected in a 1.0-ml volume directly into the spleens of NARs. All experimental groups studied received FK506 to control rejection. Animals in Group A received medium-only; Group B received HTx only; and Group C received HTx and edaravone. Forty-eight hours after transplantation, the hepatocytes from animals were isolated and analyzed for staining with propidium iodide- and annexin-V using flow cytometry. Liver sections were also studied by immunostaining for albumin, and TUNEL. Peripheral blood serum albumin levels were measured on post-transplant days 0, 3, 5, 7, 10 and 14 using ELISA. The edaravone-treated animals demonstrated an increased number of engrafted donor hepatocytes in the liver. The edaravone-treated liver sections also contained fewer TUNEL-positive cells and animals that received edaravone had higher serum albumin levels post-transplantation. Hepatocytes were also found to have increased in numbers 2 weeks following treatment with edaravone. Edaravone administration during HTx can suppress apoptosis near the transplanted cells, increasing engraftment. These studies indicate its potential usefulness for future clinical application. © 2014 Japanese Society of Hepato-Biliary-Pancreatic Surgery.

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

    Directory of Open Access Journals (Sweden)

    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.

  15. RNA synthesis in primary cultures of adult rat hepatocytes

    International Nuclear Information System (INIS)

    Fugassa, E.; Gallo, G.; Voci, A.; Cordone, A.

    1983-01-01

    The ability of hepatocyte monolayers to synthesize RNA was investigated by measuring [3H]orotic acid incorporation into RNA and the total nuclear RNA polymerase activity as a function of the time in culture. The results demonstrate that primary cultures of hepatocytes maintained in a chemically defined serum- and hormone-free medium are able to synthesize RNA actively. This ability increases within the first 2 d of culture, despite the concomitant decrease in [3H]orotic acid uptake, and decreases only after 3 d. Factors such as serum, insulin, and dexamethasone, known to improve maintenance of functional hepatocytes, markedly stimulate the uptake of labeled precursor without apparently affecting the rate of RNA synthesis by cultured cells. It is suggested that the culture of adult rat hepatocytes provides a useful experimental model for the studies of hormonal regulation of transcription in liver

  16. File list: InP.Liv.20.AllAg.Hepatocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  17. File list: InP.Liv.50.AllAg.Hepatocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  18. High efficient differentiation of functional hepatocytes from porcine induced pluripotent stem cells.

    Directory of Open Access Journals (Sweden)

    Ying Ao

    Full Text Available Hepatocyte transplantation is considered to be a promising therapy for patients with liver diseases. Induced pluripotent stem cells (iPSCs provide an unlimited source for the generation of functional hepatocytes. In this study, we generated iPSCs from porcine ear fibroblasts (PEFs by overexpressing Sox2, Klf4, Oct4, and c-Myc (SKOM, and developed a novel strategy for the efficient differentiation of hepatocyte-like cells from porcine iPSCs by following the processes of early liver development. The differentiated cells displayed the phenotypes of hepatocytes, exhibited classic hepatocyte-associated bio-functions, such as LDL uptake, glycogen storage and urea secretion, as well as possessed the metabolic activities of cytochrome P-450 (CYP 3A and 2C. Furthermore, we compared the hepatocyte differentiation efficacy of our protocol with another published method, and the results demonstrated that our differentiation strategy could significantly improve the generation of morphological and functional hepatocyte-like cells from porcine iPSCs. In conclusion, this study establishes an efficient method for in vitro generation of functional hepatocytes from porcine iPSCs, which could represent a promising cell source for preclinical testing of cell-based therapeutics for liver failure and for pharmacological applications.

  19. Methods of forming aluminum oxynitride-comprising bodies, including methods of forming a sheet of transparent armor

    Science.gov (United States)

    Chu, Henry Shiu-Hung [Idaho Falls, ID; Lillo, Thomas Martin [Idaho Falls, ID

    2008-12-02

    The invention includes methods of forming an aluminum oxynitride-comprising body. For example, a mixture is formed which comprises A:B:C in a respective molar ratio in the range of 9:3.6-6.2:0.1-1.1, where "A" is Al.sub.2O.sub.3, "B" is AlN, and "C" is a total of one or more of B.sub.2O.sub.3, SiO.sub.2, Si--Al--O--N, and TiO.sub.2. The mixture is sintered at a temperature of at least 1,600.degree. C. at a pressure of no greater than 500 psia effective to form an aluminum oxynitride-comprising body which is at least internally transparent and has at least 99% maximum theoretical density.

  20. The extracellular redox state modulates mitochondrial function, gluconeogenesis, and glycogen synthesis in murine hepatocytes.

    Science.gov (United States)

    Nocito, Laura; Kleckner, Amber S; Yoo, Elsia J; Jones Iv, Albert R; Liesa, Marc; Corkey, Barbara E

    2015-01-01

    Circulating redox state changes, determined by the ratio of reduced/oxidized pairs of different metabolites, have been associated with metabolic diseases. However, the pathogenic contribution of these changes and whether they modulate normal tissue function is unclear. As alterations in hepatic gluconeogenesis and glycogen metabolism are hallmarks that characterize insulin resistance and type 2 diabetes, we tested whether imposed changes in the extracellular redox state could modulate these processes. Thus, primary hepatocytes were treated with different ratios of the following physiological extracellular redox couples: β-hydroxybutyrate (βOHB)/acetoacetate (Acoc), reduced glutathione (GSH)/oxidized glutathione (GSSG), and cysteine/cystine. Exposure to a more oxidized ratio via extracellular βOHB/Acoc, GSH/GSSG, and cysteine/cystine in hepatocytes from fed mice increased intracellular hydrogen peroxide without causing oxidative damage. On the other hand, addition of more reduced ratios of extracellular βOHB/Acoc led to increased NAD(P)H and maximal mitochondrial respiratory capacity in hepatocytes. Greater βOHB/Acoc ratios were also associated with decreased β-oxidation, as expected with enhanced lipogenesis. In hepatocytes from fasted mice, a more extracellular reduced state of βOHB/Acoc led to increased alanine-stimulated gluconeogenesis and enhanced glycogen synthesis capacity from added glucose. Thus, we demonstrated for the first time that the extracellular redox state regulates the major metabolic functions of the liver and involves changes in intracellular NADH, hydrogen peroxide, and mitochondrial respiration. Because redox state in the blood can be communicated to all metabolically sensitive tissues, this work confirms the hypothesis that circulating redox state may be an important regulator of whole body metabolism and contribute to alterations associated with metabolic diseases.

  1. The extracellular redox state modulates mitochondrial function, gluconeogenesis, and glycogen synthesis in murine hepatocytes.

    Directory of Open Access Journals (Sweden)

    Laura Nocito

    Full Text Available Circulating redox state changes, determined by the ratio of reduced/oxidized pairs of different metabolites, have been associated with metabolic diseases. However, the pathogenic contribution of these changes and whether they modulate normal tissue function is unclear. As alterations in hepatic gluconeogenesis and glycogen metabolism are hallmarks that characterize insulin resistance and type 2 diabetes, we tested whether imposed changes in the extracellular redox state could modulate these processes. Thus, primary hepatocytes were treated with different ratios of the following physiological extracellular redox couples: β-hydroxybutyrate (βOHB/acetoacetate (Acoc, reduced glutathione (GSH/oxidized glutathione (GSSG, and cysteine/cystine. Exposure to a more oxidized ratio via extracellular βOHB/Acoc, GSH/GSSG, and cysteine/cystine in hepatocytes from fed mice increased intracellular hydrogen peroxide without causing oxidative damage. On the other hand, addition of more reduced ratios of extracellular βOHB/Acoc led to increased NAD(PH and maximal mitochondrial respiratory capacity in hepatocytes. Greater βOHB/Acoc ratios were also associated with decreased β-oxidation, as expected with enhanced lipogenesis. In hepatocytes from fasted mice, a more extracellular reduced state of βOHB/Acoc led to increased alanine-stimulated gluconeogenesis and enhanced glycogen synthesis capacity from added glucose. Thus, we demonstrated for the first time that the extracellular redox state regulates the major metabolic functions of the liver and involves changes in intracellular NADH, hydrogen peroxide, and mitochondrial respiration. Because redox state in the blood can be communicated to all metabolically sensitive tissues, this work confirms the hypothesis that circulating redox state may be an important regulator of whole body metabolism and contribute to alterations associated with metabolic diseases.

  2. File list: InP.Liv.05.AllAg.Hepatocytes [Chip-atlas[Archive

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  3. File list: InP.Liv.50.AllAg.Hepatocytes [Chip-atlas[Archive

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  4. File list: InP.Liv.20.AllAg.Hepatocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  5. File list: InP.Liv.10.AllAg.Hepatocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  6. Local laser-strengthening: Customizing the forming behavior of car body steel sheets

    Science.gov (United States)

    Wagner, M.; Jahn, A.; Beyer, E.; Balzani, D.

    2018-05-01

    Future trends in designing lightweight components especially for automotive applications increasingly require complex and delicate structures with highest possible level of capacity [1]. The manufacturing of metallic car body components is primarily realized by deep or stretch drawing. The forming process of especially cold rolled and large-sized components is typically characterized by inhomogeneous stress and strain distributions. As a result, the avoidance of undesirable deep drawing effects like earing and local necking is among the greatest challenges in forming complex car body structures [2]. Hence, a novel local laser-treatment approach with the objective of customizing the forming behavior of car body steel sheets is currently explored.

  7. Renal medullary AA amyloidosis, hepatocyte dissociation and multinucleated hepatocytes in a 14-year-old free-ranging lioness (Panthera leo

    Directory of Open Access Journals (Sweden)

    J.H. Williams

    2005-06-01

    Full Text Available A 14-year-old lioness, originating from Etosha in Namibia, and a member of a pride in Pilanesberg National Park since translocation in 1994, was euthanased due to fight-related vertebral fracture and spinal injury, incurred approximately 6-8 weeks previously. Blood specimens collected at the time of death showed mild anaemia and a leukogram reflecting stress and chronic infection. Necropsy conducted within 2 hours of death was on a dehydrated, emaciated animal with hindquarter wasting and chronic traumatic friction injuries from dragging her hindlegs. There was cellulitis in the region of bite-wounds adjacent to the thoraco-lumbar vertebral fracture, at which site there was spinal cord compression, and there was marked intestinal helminthiasis. The outer renal medullae appeared pale and waxy and the liver was macroscopically unremarkable. Histopathology and electron microscopy of the kidneys revealed multifocal to coalescing deposits of proximal medullary interstitial amyloid, which fluoresced strongly with thioflavine T, and was sensitive to potassium permanganate treatment prior to Congo Red staining, thus indicating inflammatory (AA origin. There was diffuse hepatocyte dissociation, as well as numerous binucleated and scattered multinucleated (up to 8 nuclei/cell hepatocytes, with swollen hepatocyte mitochondria, in liver examined light microscopically. Ultrastructurally, the mono-, bi- and multinucleated hepatocytes contained multifocal irregular membrane-bound accumulations of finely-granular, amorphous material both intra-cytoplasmically and intra-nuclearly, as well as evidence of irreversible mitochondrial injury. The incidence and relevance in cats and other species of amyloidosis, particularly with renal medullary distribution, as well as of hepatocyte dissociation and multinucleation, as reported in selected literature, is briefly overviewed and their occurrence in this lioness is discussed.

  8. 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.

  9. Composite materials and bodies including silicon carbide and titanium diboride and methods of forming same

    Science.gov (United States)

    Lillo, Thomas M.; Chu, Henry S.; Harrison, William M.; Bailey, Derek

    2013-01-22

    Methods of forming composite materials include coating particles of titanium dioxide with a substance including boron (e.g., boron carbide) and a substance including carbon, and reacting the titanium dioxide with the substance including boron and the substance including carbon to form titanium diboride. The methods may be used to form ceramic composite bodies and materials, such as, for example, a ceramic composite body or material including silicon carbide and titanium diboride. Such bodies and materials may be used as armor bodies and armor materials. Such methods may include forming a green body and sintering the green body to a desirable final density. Green bodies formed in accordance with such methods may include particles comprising titanium dioxide and a coating at least partially covering exterior surfaces thereof, the coating comprising a substance including boron (e.g., boron carbide) and a substance including carbon.

  10. Clinical value of hemoglobin and its association with hepatocyte steatosis in chronic hepatitis B patients

    Directory of Open Access Journals (Sweden)

    WANG Peng

    2017-07-01

    Full Text Available :ObjectiveTo investigate the clinical value of hemoglobin and its association with hepatocyte steatosis in chronic hepatitis B (CHB patients. MethodsA retrospective analysis was performed for the clinical and pathological data of 1580 CHB patients who were hospitalized in The First People′s Hospital of Shunde from January 2006 to December 2014 and underwent liver biopsy, among whom 216 (13.67% had hepatocyte steatosis (hepatocyte steatosis group and 1364 had no hepatocyte steatosis (non-hepatocyte steatosis group. The patients were divided into groups 1, 2, and 3 according to hemoglobin level, and the clinical and pathological features were analyzed and compared between the three groups. The t-test was used for comparison of continuous data between group; a one-way analysis of variance was used for comparision between multiple groups. The Mann-Whitney U test was used for ranked data between groups. The Kruskal-wallis H test was used for ranked data between multiple groups; the chi-square test was used for comparison of categorical data between groups. Spearman correlation analysis was also performed to determine the correlation between two variables. Univariate logistic regression analysis and multivariate stepwise regression analysis were used to identify the influencing factors for hepatocyte steatosis. ResultsBody mass index (BMI, systolic pressure, diastolic pressure, uric acid, total cholesterol, low-density lipoprotein, and HBV DNA load increased with the increase in hemoglobin level (F=12718,3024,4026,4624,38276,28108,7358, all P<0.05. The incidence rates of hepatocyte steatosis in groups 1, 2, and 3 were 7.59%, 1176%,and 21.67%, respectively (χ2=44.23, P<0.05. Hemoglobin was positively correlated with hepatic steatosis (rs=0.211, P<0001. The multivariate logistic regression analysis showed that hemoglobin (odds ratio [OR]=1.066, P<0.05, BMI (OR=1576, P<005, age (OR=1.041, P<0.05, sex

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  15. Hepatocyte produced matrix metalloproteinases are regulated by CD147 in liver fibrogenesis.

    Science.gov (United States)

    Calabro, Sarah R; Maczurek, Annette E; Morgan, Alison J; Tu, Thomas; Wen, Victoria W; Yee, Christine; Mridha, Auvro; Lee, Maggie; d'Avigdor, William; Locarnini, Stephen A; McCaughan, Geoffrey W; Warner, Fiona J; McLennan, Susan V; Shackel, Nicholas A

    2014-01-01

    The classical paradigm of liver injury asserts that hepatic stellate cells (HSC) produce, remodel and turnover the abnormal extracellular matrix (ECM) of fibrosis via matrix metalloproteinases (MMPs). In extrahepatic tissues MMP production is regulated by a number of mechanisms including expression of the glycoprotein CD147. Previously, we have shown that CD147 is expressed on hepatocytes but not within the fibrotic septa in cirrhosis [1]. Therefore, we investigated if hepatocytes produce MMPs, regulated by CD147, which are capable of remodelling fibrotic ECM independent of the HSC. Non-diseased, fibrotic and cirrhotic livers were examined for MMP activity and markers of fibrosis in humans and mice. CD147 expression and MMP activity were co-localised by in-situ zymography. The role of CD147 was studied in-vitro with siRNA to CD147 in hepatocytes and in-vivo in mice with CCl4 induced liver injury using ãCD147 antibody intervention. In liver fibrosis in both human and mouse tissue MMP expression and activity (MMP-2, -9, -13 and -14) increased with progressive injury and localised to hepatocytes. Additionally, as expected, MMPs were abundantly expressed by activated HSC. Further, with progressive fibrosis there was expression of CD147, which localised to hepatocytes but not to HSC. Functionally significant in-vitro regulation of hepatocyte MMP production by CD147 was demonstrated using siRNA to CD147 that decreased hepatocyte MMP-2 and -9 expression/activity. Further, in-vivo α-CD147 antibody intervention decreased liver MMP-2, -9, -13, -14, TGF-β and α-SMA expression in CCl4 treated mice compared to controls. We have shown that hepatocytes produce active MMPs and that the glycoprotein CD147 regulates hepatocyte MMP expression. Targeting CD147 regulates hepatocyte MMP production both in-vitro and in-vivo, with the net result being reduced fibrotic matrix turnover in-vivo. Therefore, CD147 regulation of hepatocyte MMP is a novel pathway that could be targeted by

  16. Hepatocyte produced matrix metalloproteinases are regulated by CD147 in liver fibrogenesis.

    Directory of Open Access Journals (Sweden)

    Sarah R Calabro

    Full Text Available The classical paradigm of liver injury asserts that hepatic stellate cells (HSC produce, remodel and turnover the abnormal extracellular matrix (ECM of fibrosis via matrix metalloproteinases (MMPs. In extrahepatic tissues MMP production is regulated by a number of mechanisms including expression of the glycoprotein CD147. Previously, we have shown that CD147 is expressed on hepatocytes but not within the fibrotic septa in cirrhosis [1]. Therefore, we investigated if hepatocytes produce MMPs, regulated by CD147, which are capable of remodelling fibrotic ECM independent of the HSC.Non-diseased, fibrotic and cirrhotic livers were examined for MMP activity and markers of fibrosis in humans and mice. CD147 expression and MMP activity were co-localised by in-situ zymography. The role of CD147 was studied in-vitro with siRNA to CD147 in hepatocytes and in-vivo in mice with CCl4 induced liver injury using ãCD147 antibody intervention.In liver fibrosis in both human and mouse tissue MMP expression and activity (MMP-2, -9, -13 and -14 increased with progressive injury and localised to hepatocytes. Additionally, as expected, MMPs were abundantly expressed by activated HSC. Further, with progressive fibrosis there was expression of CD147, which localised to hepatocytes but not to HSC. Functionally significant in-vitro regulation of hepatocyte MMP production by CD147 was demonstrated using siRNA to CD147 that decreased hepatocyte MMP-2 and -9 expression/activity. Further, in-vivo α-CD147 antibody intervention decreased liver MMP-2, -9, -13, -14, TGF-β and α-SMA expression in CCl4 treated mice compared to controls.We have shown that hepatocytes produce active MMPs and that the glycoprotein CD147 regulates hepatocyte MMP expression. Targeting CD147 regulates hepatocyte MMP production both in-vitro and in-vivo, with the net result being reduced fibrotic matrix turnover in-vivo. Therefore, CD147 regulation of hepatocyte MMP is a novel pathway that could be

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  1. Galactosylated DNA lipid nanocapsules for efficient hepatocyte targeting.

    Science.gov (United States)

    Morille, M; Passirani, C; Letrou-Bonneval, E; Benoit, J-P; Pitard, B

    2009-09-11

    The main objective of gene therapy via a systemic pathway is the development of a stable and non-toxic gene vector that can encapsulate and deliver foreign genetic materials into specific cell types with the transfection efficiency of viral vectors. With this objective, DNA complexed with cationic lipids of DOTAP/DOPE was encapsulated into lipid nanocapsules (LNCs) forming nanocarriers (DNA LNCs) with a size suitable for systemic injection (109+/-6 nm). With the goal of increasing systemic delivery, LNCs were stabilised with long chains of poly(ethylene glycol) (PEG), either from a PEG lipid derivative (DSPE-mPEG(2000)) or from an amphiphilic block copolymer (F108). In order to overcome internalisation difficulties encountered with PEG shield, a specific ligand (galactose) was covalently added at the distal end of the PEG chains, in order to provide active targeting of the asialoglycoprotein-receptor present on hepatocytes. This study showed that DNA LNCs were as efficient as positively charged DOTAP/DOPE lipoplexes for transfection. In primary hepatocytes, when non-galactosylated, the two polymers significantly decreased the transfection, probably by creating a barrier around the DNA LNCs. Interestingly, galactosylated F108 coated DNA LNCs led to a 18-fold increase in luciferase expression compared to non-galactosylated ones.

  2. Cell polarity development and protein trafficking in hepatocytes lacking E-cadherin/beta-catenin-based adherens junctions

    NARCIS (Netherlands)

    Theard, Delphine; Steiner, Magdalena; Kalicharan, Dharamdajal; Hoekstra, Dick; van IJzendoorn, Sven C. D.

    Using a mutant hepatocyte cell line in which E-cadherin and ss-catenin are completely depleted from the cell surface, and, consequently, fail to form adherens junctions, we have investigated adherens junction requirement for apical-basolateral polarity development and polarized membrane trafficking.

  3. Scintigraphic evidence of transplanted hepatocytes in spleen and liver

    International Nuclear Information System (INIS)

    Henne-Bruns, D.; Kremer, B.; Gramminger, K.; Broelsch, C.

    1986-01-01

    In rats suffering from hepatic enzymatic deficiency transplanted hepatocytes could be evidenced scintigraphically in liver, spleen and granulomas. In pigs, however, it is very difficult to demonstrate transplanted hepatocytes by scintiscanning because of the thickness of the tissues and the high background radiation in large animals

  4. Method for Forming Fiber Reinforced Composite Bodies with Graded Composition and Stress Zones

    Science.gov (United States)

    Singh, Mrityunjay (Inventor); Levine, Stanley R. (Inventor); Smialek, James A. (Inventor)

    1999-01-01

    A near-net, complex shaped ceramic fiber reinforced silicon carbide based composite bodies with graded compositions and stress zones is disclosed. To provide the composite a fiber preform is first fabricated and an interphase is applied by chemical vapor infiltration, sol-gel or polymer processes. This first body is further infiltrated with a polymer mixture containing carbon, and/or silicon carbide, and additional oxide, carbide, or nitride phases forming a second body. One side of the second body is spray coated or infiltrated with slurries containing high thermal expansion and oxidation resistant. crack sealant phases and the other side of this second body is coated with low expansion phase materials to form a third body. This third body consisting of porous carbonaceous matrix surrounding the previously applied interphase materials, is then infiltrated with molten silicon or molten silicon-refractory metal alloys to form a fourth body. The resulting fourth body comprises dense composites consisting of fibers with the desired interphase which are surrounded by silicon carbide and other second phases materials at the outer and inner surfaces comprising material of silicon, germanium, refractory metal suicides, borides, carbides, oxides, and combinations thereof The resulting composite fourth body has different compositional patterns from one side to the other.

  5. A preliminary study for constructing a bioartificial liver device with induced pluripotent stem cell-derived hepatocytes

    Directory of Open Access Journals (Sweden)

    Iwamuro Masaya

    2012-12-01

    Full Text Available Abstract Background Bioartificial liver systems, designed to support patients with liver failure, are composed of bioreactors and functional hepatocytes. Immunological rejection of the embedded hepatocytes by the host immune system is a serious concern that crucially degrades the performance of the device. Induced pluripotent stem (iPS cells are considered a desirable source for bioartificial liver systems, because patient-derived iPS cells are free from immunological rejection. The purpose of this paper was to test the feasibility of a bioartificial liver system with iPS cell-derived hepatocyte-like cells. Methods Mouse iPS cells were differentiated into hepatocyte-like cells by a multi-step differentiation protocol via embryoid bodies and definitive endoderm. Differentiation of iPS cells was evaluated by morphology, PCR assay, and functional assays. iPS cell-derived hepatocyte-like cells were cultured in a bioreactor module with a pore size of 0.2 μm for 7 days. The amount of albumin secreted into the circulating medium was analyzed by ELISA. Additionally, after a 7-day culture in a bioreactor module, cells were observed by a scanning electron microscope. Results At the final stage of the differentiation program, iPS cells changed their morphology to a polygonal shape with two nucleoli and enriched cytoplasmic granules. Transmission electron microscope analysis revealed their polygonal shape, glycogen deposition in the cytoplasm, microvilli on their surfaces, and a duct-like arrangement. PCR analysis showed increased expression of albumin mRNA over the course of the differentiation program. Albumin and urea production was also observed. iPS-Heps culture in bioreactor modules showed the accumulation of albumin in the medium for up to 7 days. Scanning electron microscopy revealed the attachment of cell clusters to the hollow fibers of the module. These results indicated that iPS cells were differentiated into hepatocyte-like cells after culture

  6. Transplant of Hepatocytes, Undifferentiated Mesenchymal Stem Cells, and In Vitro Hepatocyte-Differentiated Mesenchymal Stem Cells in a Chronic Liver Failure Experimental Model: A Comparative Study.

    Science.gov (United States)

    El Baz, Hanan; Demerdash, Zeinab; Kamel, Manal; Atta, Shimaa; Salah, Faten; Hassan, Salwa; Hammam, Olfat; Khalil, Heba; Meshaal, Safa; Raafat, Inas

    2018-02-01

    Liver transplant is the cornerstone line of treatment for chronic liver diseases; however, the long list of complications and obstacles stand against this operation. Searching for new modalities for treatment of chronic liver illness is a must. In the present research, we aimed to compare the effects of transplant of undifferentiated human mesenchymal stem cells, in vitro differentiated mesenchymal stem cells, and adult hepatocytes in an experimental model of chronic liver failure. Undifferentiated human cord blood mesenchymal stem cells were isolated, pro-pagated, and characterized by morphology, gene expression analysis, and flow cytometry of surface markers and in vitro differentiated into hepatocyte-like cells. Rat hepatocytes were isolated by double perfusion technique. An animal model of chronic liver failure was developed, and undifferentiated human cord blood mesenchymal stem cells, in vitro hepato-genically differentiated mesenchymal stem cells, or freshly isolated rat hepatocytes were transplanted into a CCL4 cirrhotic experimental model. Animals were killed 3 months after transplant, and liver functions and histopathology were assessed. Compared with the cirrhotic control group, the 3 cell-treated groups showed improved alanine aminotransferase, aspartate aminotransferase, albumin, and bilirubin levels, with best results shown in the hepatocyte-treated group. Histopathologic examination of the treated groups showed improved fibrosis, with best results obtained in the undifferentiated mesenchymal stem cell-treated group. Both adult hepatocytes and cord blood mesenchymal stem cells proved to be promising candidates for cell-based therapy in liver regeneration on an experimental level. Improved liver function was evident in the hepatocyte-treated group, and fibrosis control was more evident in the undifferentiated mesenchymal stem cell-treated group.

  7. Differentiation of monkey embryonic stem cells to hepatocytes by feeder-free dispersion culture and expression analyses of cytochrome p450 enzymes responsible for drug metabolism.

    Science.gov (United States)

    Maruyama, Junya; Matsunaga, Tamihide; Yamaori, Satoshi; Sakamoto, Sakae; Kamada, Noboru; Nakamura, Katsunori; Kikuchi, Shinji; Ohmori, Shigeru

    2013-01-01

    We reported previously that monkey embryonic stem cells (ESCs) were differentiated into hepatocytes by formation of embryoid bodies (EBs). However, this EB formation method is not always efficient for assays using a large number of samples simultaneously. A dispersion culture system, one of the differentiation methods without EB formation, is able to more efficiently provide a large number of feeder-free undifferentiated cells. A previous study demonstrated the effectiveness of the Rho-associated kinase inhibitor Y-27632 for feeder-free dispersion culture and induction of differentiation of monkey ESCs into neural cells. In the present study, the induction of differentiation of cynomolgus monkey ESCs (cmESCs) into hepatocytes was performed by the dispersion culture method, and the expression and drug inducibility of cytochrome P450 (CYP) enzymes in these hepatocytes were examined. The cmESCs were successfully differentiated into hepatocytes under feeder-free dispersion culture conditions supplemented with Y-27632. The hepatocytes differentiated from cmESCs expressed the mRNAs for three hepatocyte marker genes (α-fetoprotein, albumin, CYP7A1) and several CYP enzymes, as measured by real-time polymerase chain reaction. In particular, the basal expression of cmCYP3A4 (3A8) in these hepatocytes was detected at mRNA and enzyme activity (testosterone 6β-hydroxylation) levels. Furthermore, the expression and activity of cmCYP3A4 (3A8) were significantly upregulated by rifampicin. These results indicated the effectiveness of Y-27632 supplementation for feeder-free dispersed culture and induction of differentiation into hepatocytes, and the expression of functional CYP enzyme(s) in cmESC-derived hepatic cells.

  8. A refined characterisation of the NeoHepatocyte phenotype necessitates a reappraisal of the transdifferentiation hypothesis.

    Science.gov (United States)

    Riquelme, Paloma; Wundt, Judith; Hutchinson, James A; Brulport, Marc; Jun, Yu; Sotnikova, Anna; Girreser, Ulrich; Braun, Felix; Gövert, Felix; Soria, Bernat; Nüssler, Andreas; Clement, Bernd; Hengstler, Jan G; Fändrich, Fred

    2009-03-01

    Under certain culture conditions human peripheral blood monocytes may be induced to express phenotypic markers of non-haematopoietic lineages, including hepatocyte-defining traits. One such example, the NeoHepatocyte, was previously shown to express a broad panel of hepatocyte-like marker antigens and metabolic activities, both in vitro and following engraftment in the liver of immunodeficient mice. In this report, a refined description of NeoHepatocytes, with regard to their expression of xenobiotic-metabolising enzymes, morphology, hepatocyte marker expression and cell surface phenotype, is presented in comparison with human macrophages in defined states of activation. Contrary to prior assertions, it would seem more likely that NeoHepatocytes express particular hepatocyte-defining genes during a normal programme of macrophage differentiation rather than undergoing a process of transdifferentiation to become hepatocyte-like cells.

  9. Lack of direct mitogenic activity of dichloroacetate and trichloroacetate in cultured rat hepatocytes

    International Nuclear Information System (INIS)

    Walgren, Jennie L.; Kurtz, David T.; McMillan, JoEllyn M.

    2005-01-01

    Dichloroacetate (DCA) and trichloroacetate (TCA) are hepatocarcinogenic metabolites of the common groundwater contaminant, 1,1,2-trichloroethylene. DCA and TCA have been shown to induce hepatocyte proliferation in vivo, but it is not known if this response is the result of direct mitogenic activity or whether cell replication occurs indirectly in response to tissue injury or inflammation. In this study we used primary cultures of rat hepatocytes, a species susceptible to DCA- but not TCA-induced hepatocarcinogenesis, to determine whether DCA and TCA are direct hepatocyte mitogens. Rat hepatocytes, cultured in growth factor-free medium, were treated with 0.01-1.0 mM DCA or TCA for 10-40 h; cell replication was then assessed by measuring incorporation of 3 H-thymidine into DNA and by cell counts. DCA or TCA treatment did not alter 3 H-thymidine incorporation in the cultured hepatocytes. Although an increase in cell number was not observed, DCA treatment significantly abrogated the normal background cell loss, suggesting an ability to inhibit apoptotic cell death in primary hepatocyte cultures. Furthermore, treatment with DCA synergistically enhanced the mitogenic response to epidermal growth factor. The data indicate that DCA and TCA are not direct mitogens in hepatocyte cultures, which is of interest in view of their ability to stimulate hepatocyte replication in vivo. Nevertheless, the synergistic enhancement of epidermal growth factor-induced hepatocyte replication by DCA is of particular interest and warrants further study

  10. Immortalized human hepatocytes as a tool for the study of hepatocytic (de-)differentiation

    NARCIS (Netherlands)

    Schippers, IJ; Moshage, H; Roelofsen, H; Muller, M; Heymans, HSA; Ruiters, M; Kuipers, F

    Primary human hepatocytes were immortalized by stable transfection with a recombinant plasmid containing the early region of simian virus (SV) 40. The cells were cultured in serum-free, hormonally defined medium during the immortalization procedure. Foci of dividing cells were seen after 3 months.

  11. Trifluoperazine inhibits acetaminophen-induced hepatotoxicity and hepatic reactive nitrogen formation in mice and in freshly isolated hepatocytes

    Directory of Open Access Journals (Sweden)

    Sudip Banerjee

    Full Text Available The hepatotoxicity of acetaminophen (APAP occurs by initial metabolism to N-acetyl-p-benzoquinone imine which depletes GSH and forms APAP-protein adducts. Subsequently, the reactive nitrogen species peroxynitrite is formed from nitric oxide (NO and superoxide leading to 3-nitrotyrosine in proteins. Toxicity occurs with inhibited mitochondrial function. We previously reported that in hepatocytes the nNOS (NOS1 inhibitor NANT inhibited APAP toxicity, reactive nitrogen and oxygen species formation, and mitochondrial dysfunction. In this work we examined the effect of trifluoperazine (TFP, a calmodulin antagonist that inhibits calcium induced nNOS activation, on APAP hepatotoxicity and reactive nitrogen formation in murine hepatocytes and in vivo. In freshly isolated hepatocytes TFP inhibited APAP induced toxicity, reactive nitrogen formation (NO, GSNO, and 3-nitrotyrosine in protein, reactive oxygen formation (superoxide, loss of mitochondrial membrane potential, decreased ATP production, decreased oxygen consumption rate, and increased NADH accumulation. TFP did not alter APAP induced GSH depletion in the hepatocytes or the formation of APAP protein adducts which indicated that reactive metabolite formation was not inhibited. Since we previously reported that TFP inhibits the hepatotoxicity of APAP in mice without altering hepatic APAP-protein adduct formation, we examined the APAP treated mouse livers for evidence of reactive nitrogen formation. 3-Nitrotyrosine in hepatic proteins and GSNO were significantly increased in APAP treated mouse livers and decreased in the livers of mice treated with APAP plus TFP. These data are consistent with a hypothesis that APAP hepatotoxicity occurs with altered calcium metabolism, activation of nNOS leading to increased reactive nitrogen formation, and mitochondrial dysfunction. Keywords: Acetaminophen, Neuronal nitric oxide, Oxidative stress, Mitochondria

  12. Hypoxia-inducible factor-dependent production of profibrotic mediators by hypoxic hepatocytes.

    Science.gov (United States)

    Copple, Bryan L; Bustamante, Juan J; Welch, Timothy P; Kim, Nam Deuk; Moon, Jeon-Ok

    2009-08-01

    During the development of liver fibrosis, mediators are produced that stimulate cells in the liver to differentiate into myofibroblasts and to produce collagen. Recent studies demonstrated that the transcription factor, hypoxia-inducible factor-1alpha (HIF-1alpha), is critical for upregulation of profibrotic mediators, such as platelet-derived growth factor-A (PDGF-A), PDGF-B and plasminogen activator inhibitor-1 (PAI-1) in the liver, during the development of fibrosis. What remains unknown is the cell type-specific regulation of these genes by HIF-1alpha in liver cell types. Accordingly, the hypothesis was tested that HIF-1alpha is activated in hypoxic hepatocytes and regulates the production of profibrotic mediators by these cells. In this study, hepatocytes were isolated from the livers of control and HIF-1alpha- or HIF-1beta-deficient mice and exposed to hypoxia. Exposure of primary mouse hepatocytes to 1% oxygen stimulated nuclear accumulation of HIF-1alpha and upregulated PAI-1, vascular endothelial cell growth factor and the vasoactive peptides adrenomedullin-1 (ADM-1) and ADM-2. In contrast, the levels of PDGF-A and PDGF-B mRNAs were unaffected in these cells by hypoxia. Exposure of HIF-1alpha-deficient hepatocytes to 1% oxygen only partially prevented upregulation of these genes, suggesting that other hypoxia-regulated transcription factors, such as HIF-2alpha, may also regulate these genes. In support of this, HIF-2alpha was activated in hypoxic hepatocytes, and exposure of HIF-1beta-deficient hepatocytes to 1% oxygen completely prevented upregulation of PAI-1, vascular endothelial cell growth factor and ADM-1, suggesting that HIF-2alpha may also contribute to upregulation of these genes in hypoxic hepatocytes. Collectively, our results suggest that HIFs may be important regulators of profibrotic and vasoactive mediators by hypoxic hepatocytes.

  13. 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 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 inhibition of bile salt transport. Published by Elsevier Ireland Ltd.

  14. A complex of meteorite-forming bodies (the Innisfree - Ridgedale family).

    Science.gov (United States)

    Shestaka, I. S.

    1994-12-01

    For the first time a swarm of meteorite-forming bodies was identified. Yearly this swarm's orbit approaches the Earth's orbit in early February. This swarm contains the Innisfree and Ridgedale fireballs, 9 small meteoric swarms, several asteroids and 12 fireballs photographed by the cameras of the Prairie Network and Canadian Meteorite Observation and Discovery Project. The discovery of this complex, intensive bombardments of the Moon's surface recorded by means of seismographs left on the Moon, the analysis of the time distributions of meteorite falls on the Earth and other established facts confirm the existence of swarms of meteorite-forming bodies which are crossing the Earth's orbit.

  15. Higher protein kinase C ζ in fatty rat liver and its effect on insulin actions in primary hepatocytes.

    Directory of Open Access Journals (Sweden)

    Wei Chen

    Full Text Available We previously showed the impairment of insulin-regulated gene expression in the primary hepatocytes from Zucker fatty (ZF rats, and its association with alterations of hepatic glucose and lipid metabolism. However, the molecular mechanism is unknown. A preliminary experiment shows that the expression level of protein kinase C ζ (PKCζ, a member of atypical PKC family, is higher in the liver and hepatocytes of ZF rats than that of Zucker lean (ZL rats. Herein, we intend to investigate the roles of atypical protein kinase C in the regulation of hepatic gene expression. The insulin-regulated hepatic gene expression was evaluated in ZL primary hepatocytes treated with atypical PKC recombinant adenoviruses. Recombinant adenovirus-mediated overexpression of PKCζ, or the other atypical PKC member PKCι/λ, alters the basal and impairs the insulin-regulated expressions of glucokinase, sterol regulatory element-binding protein 1c, the cytosolic form of phosphoenolpyruvate carboxykinase, the catalytic subunit of glucose 6-phosphatase, and insulin like growth factor-binding protein 1 in ZL primary hepatocytes. PKCζ or PKCι/λ overexpression also reduces the protein level of insulin receptor substrate 1, and the insulin-induced phosphorylation of AKT at Ser473 and Thr308. Additionally, PKCι/λ overexpression impairs the insulin-induced Prckz expression, indicating the crosstalk between PKCζ and PKCι/λ. We conclude that the PKCζ expression is elevated in hepatocytes of insulin resistant ZF rats. Overexpressions of aPKCs in primary hepatocytes impair insulin signal transduction, and in turn, the down-stream insulin-regulated gene expression. These data suggest that elevation of aPKC expression may contribute to the hepatic insulin resistance at gene expression level.

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

    Directory of Open Access Journals (Sweden)

    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.

  17. Hepatocyte Hypoxia Inducible Factor-1 Mediates the Development of Liver Fibrosis in a Mouse Model of Nonalcoholic Fatty Liver Disease.

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    Omar A Mesarwi

    Full Text Available Obstructive sleep apnea (OSA is associated with the progression of non-alcoholic fatty liver disease (NAFLD to steatohepatitis and fibrosis. This progression correlates with the severity of OSA-associated hypoxia. In mice with diet induced obesity, hepatic steatosis leads to liver tissue hypoxia, which worsens with exposure to intermittent hypoxia. Emerging data has implicated hepatocyte cell signaling as an important factor in hepatic fibrogenesis. We hypothesized that hepatocyte specific knockout of the oxygen sensing α subunit of hypoxia inducible factor-1 (HIF-1, a master regulator of the global response to hypoxia, may be protective against the development of liver fibrosis.Wild-type mice and mice with hepatocyte-specific HIF-1α knockout (Hif1a-/-hep were fed a high trans-fat diet for six months, as a model of NAFLD. Hepatic fibrosis was evaluated by Sirius red stain and hydroxyproline assay. Liver enzymes, fasting insulin, and hepatic triglyceride content were also assessed. Hepatocytes were isolated from Hif1a-/-hep mice and wild-type controls and were exposed to sustained hypoxia (1% O2 or normoxia (16% O2 for 24 hours. The culture media was used to reconstitute type I collagen and the resulting matrices were examined for collagen cross-linking.Wild-type mice on a high trans-fat diet had 80% more hepatic collagen than Hif1a-/-hep mice (2.21 μg collagen/mg liver tissue, versus 1.23 μg collagen/mg liver tissue, p = 0.03, which was confirmed by Sirius red staining. Body weight, liver weight, mean hepatic triglyceride content, and fasting insulin were similar between groups. Culture media from wild-type mouse hepatocytes exposed to hypoxia allowed for avid collagen cross-linking, but very little cross-linking was seen when hepatocytes were exposed to normoxia, or when hepatocytes from Hif1a-/-hep mice were used in hypoxia or normoxia.Hepatocyte HIF-1 mediates an increase in liver fibrosis in a mouse model of NAFLD, perhaps due to liver

  18. Gender differences in methionine accumulation and metabolism in freshly isolated mouse hepatocytes: Potential roles in toxicity

    International Nuclear Information System (INIS)

    Dever, Joseph T.; Elfarra, Adnan A.

    2009-01-01

    L-Methionine (Met) is hepatotoxic at high concentrations. Because Met toxicity in freshly isolated mouse hepatocytes is gender-dependent, the goal of this study was to assess the roles of Met accumulation and metabolism in the increased sensitivity of male hepatocytes to Met toxicity compared with female hepatocytes. Male hepatocytes incubated with Met (30 mM) at 37 o C exhibited higher levels of intracellular Met at 0.5, 1.0, and 1.5 h, respectively, compared to female hepatocytes. Conversely, female hepatocytes had higher levels of S-adenosyl-L-methionine compared to male hepatocytes. Female hepatocytes also exhibited higher L-methionine-L-sulfoxide levels relative to control hepatocytes, whereas the increases in L-methionine-D-sulfoxide (Met-D-O) levels were similar in hepatocytes of both genders. Addition of aminooxyacetic acid (AOAA), an inhibitor of Met transamination, significantly increased Met levels at 1.5 h and increased Met-D-O levels at 1.0 and 1.5 h only in Met-exposed male hepatocytes. No gender differences in cytosolic Met transamination activity by glutamine transaminase K were detected. However, female mouse liver cytosol exhibited higher methionine-DL-sulfoxide (MetO) reductase activity than male mouse liver cytosol at low (0.25 and 0.5 mM) MetO concentrations. Collectively, these results suggest that increased cellular Met accumulation, decreased Met transmethylation, and increased Met and MetO transamination in male mouse hepatocytes may be contributing to the higher sensitivity of the male mouse hepatocytes to Met toxicity in comparison with female mouse hepatocytes.

  19. Interspecies differences in metabolism of arsenic by cultured primary hepatocytes

    International Nuclear Information System (INIS)

    Drobna, Zuzana; Walton, Felecia S.; Harmon, Anne W.; Thomas, David J.; Styblo, Miroslav

    2010-01-01

    Biomethylation is the major pathway for the metabolism of inorganic arsenic (iAs) in many mammalian species, including the human. However, significant interspecies differences have been reported in the rate of in vivo metabolism of iAs and in yields of iAs metabolites found in urine. Liver is considered the primary site for the methylation of iAs and arsenic (+3 oxidation state) methyltransferase (As3mt) is the key enzyme in this pathway. Thus, the As3mt-catalyzed methylation of iAs in the liver determines in part the rate and the pattern of iAs metabolism in various species. We examined kinetics and concentration-response patterns for iAs methylation by cultured primary hepatocytes derived from human, rat, mice, dog, rabbit, and rhesus monkey. Hepatocytes were exposed to [ 73 As]arsenite (iAs III ; 0.3, 0.9, 3.0, 9.0 or 30 nmol As/mg protein) for 24 h and radiolabeled metabolites were analyzed in cells and culture media. Hepatocytes from all six species methylated iAs III to methylarsenic (MAs) and dimethylarsenic (DMAs). Notably, dog, rat and monkey hepatocytes were considerably more efficient methylators of iAs III than mouse, rabbit or human hepatocytes. The low efficiency of mouse, rabbit and human hepatocytes to methylate iAs III was associated with inhibition of DMAs production by moderate concentrations of iAs III and with retention of iAs and MAs in cells. No significant correlations were found between the rate of iAs methylation and the thioredoxin reductase activity or glutathione concentration, two factors that modulate the activity of recombinant As3mt. No associations between the rates of iAs methylation and As3mt protein structures were found for the six species examined. Immunoblot analyses indicate that the superior arsenic methylation capacities of dog, rat and monkey hepatocytes examined in this study may be associated with a higher As3mt expression. However, factors other than As3mt expression may also contribute to the interspecies differences

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

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    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

  1. Cell swelling and glycogen metabolism in hepatocytes from fasted rats

    NARCIS (Netherlands)

    Gustafson, L. A.; Jumelle-Laclau, M. N.; van Woerkom, G. M.; van Kuilenburg, A. B.; Meijer, A. J.

    1997-01-01

    Cell swelling is known to increase net glycogen production from glucose in hepatocytes from fasted rats by activating glycogen synthase. Since both active glycogen synthase and phosphorylase are present in hepatocytes, suppression of flux through phosphorylase may also contribute to the net increase

  2. Sodium-independent, bicuculline-sensitive [3H]GABA binding to isolated rat hepatocytes

    International Nuclear Information System (INIS)

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

    1987-01-01

    To determine whether hepatocytes possess specific receptor sites for gamma-aminobutyric acid (GABA), a potent amino acid neurotransmitter, [ 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 [ 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

  3. Controlled cell morphology and liver-specific function of engineered primary hepatocytes by fibroblast layer cell densities.

    Science.gov (United States)

    Sakai, Yusuke; Koike, Makiko; Kawahara, Daisuke; Hasegawa, Hideko; Murai, Tomomi; Yamanouchi, Kosho; Soyama, Akihiko; Hidaka, Masaaki; Takatsuki, Mitsuhisa; Fujita, Fumihiko; Kuroki, Tamotsu; Eguchi, Susumu

    2018-03-05

    Engineered primary hepatocytes, including co-cultured hepatocyte sheets, are an attractive to basic scientific and clinical researchers because they maintain liver-specific functions, have reconstructed cell polarity, and have high transplantation efficiency. However, co-culture conditions regarding engineered primary hepatocytes were suboptimal in promoting these advantages. Here we report that the hepatocyte morphology and liver-specific function levels are controlled by the normal human diploid fibroblast (TIG-118 cell) layer cell density. Primary rat hepatocytes were plated onto TIG-118 cells, previously plated 3 days before at 1.04, 5.21, and 26.1×10 3  cells/cm 2 . Hepatocytes plated onto lower TIG-118 cell densities expanded better during the early culture period. The hepatocytes gathered as colonies and only exhibited small adhesion areas because of the pushing force from proliferating TIG-118 cells. The smaller areas of each hepatocyte result in the development of bile canaliculi. The highest density of TIG-118 cells downregulated albumin synthesis activity of hepatocytes. The hepatocytes may have undergone apoptosis associated with high TGF-β1 concentration and necrosis due to a lack of oxygen. These occurrences were supported by apoptotic chromatin condensation and high expression of both proteins HIF-1a and HIF-1b. Three types of engineered hepatocyte/fibroblast sheets comprising different TIG-118 cell densities were harvested after 4 days of hepatocyte culture and showed a complete cell sheet format without any holes. Hepatocyte morphology and liver-specific function levels are controlled by TIG-118 cell density, which helps to design better engineered hepatocytes for future applications such as in vitro cell-based assays and transplantable hepatocyte tissues. Copyright © 2018 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  4. Property of hepatitis B virus replication in Tupaia belangeri hepatocytes.

    Science.gov (United States)

    Sanada, Takahiro; Tsukiyama-Kohara, Kyoko; Yamamoto, Naoki; Ezzikouri, Sayeh; Benjelloun, Soumaya; Murakami, Shuko; Tanaka, Yasuhito; Tateno, Chise; Kohara, Michinori

    2016-01-08

    The northern treeshrew (Tupaia belangeri) has been reported to be an effective candidate for animal infection model with hepatitis B virus (HBV). The objective of our study was to analyze the growth characteristics of HBV in tupaia hepatocytes and the host response to HBV infection. We established primary tupaia hepatocytes (3-6-week old tupaia) and infected them with HBV genotypes A, B and C, and all the genotypes proliferated as well as those in human primary hepatocytes (>10(5) copies/ml in culture supernatant). We next generated a chimeric mouse with tupaia liver by transplantation of tupaia primary hepatocytes to urokinase-type plasminogen activator cDNA (cDNA-uPA)/severe combined immunodeficient (SCID) mice and the replacement ratio with tupaia hepatocytes was found to be more than 95%. Infection of chimeric mice with HBV (genotypes B, C, and D) resulted in HBV-DNA level of 10(4)-10(6) copies/ml after 8 weeks of infection, which were almost similar to that in humanized chimeric mouse. In contrast, serum HBV level in adult tupaia (1-year-old tupaia) was quite low (<10(3) copies/ml). Understanding the differences in the response to HBV infection in primary tupaia hepatocytes, chimeric mouse, and adult tupaia will contribute to elucidating the mechanism of persistent HBV infection and viral eradication. Thus, T. belangeri was found to be efficient for studying the host response to HBV infection, thereby providing novel insight into the pathogenesis of HBV. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  5. Temperature shift and host cell contact up-regulate sporozoite expression of Plasmodium falciparum genes involved in hepatocyte infection.

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    Anthony Siau

    proteins involved in hepatocyte invasion, while the other two were predominantly expressed during hepatic parasite development. The genome-wide up-regulation of expression observed supports the hypothesis that the shift from the mosquito to the mammalian host contributes to activate quiescent salivary gland sporozoites into a state of readiness for the hepatic stages. Functional studies on four of the up-regulated genes validated our approach as one means to determine the repertoire of proteins implicated during the early events of the Plasmodium infection, and in this case that of P. falciparum, the species responsible for the severest forms of malaria.

  6. Effect of hepatocyte growth factor on radiation response of HeLa, V79, CHO and primary cultured parenchymal hepatocyte in vitro

    International Nuclear Information System (INIS)

    Yamazaki, Hideya; Inoue, Takehiro; Nose, Takayuki; Murayama, Shigeyuki; Teshima, Teruki; Ozeki, Syuji; Koizumi, Masahiko; Inoue, Toshihiko.

    1996-01-01

    Hepatocyte growth factor (HGF) is a multipotent cytokine enhancing regeneration of injured organs as liver, kidney and lung after injury. HGF enhances proliferation of various type of cells, inhibits proliferation of carcinoma cells, enhances motility of epithelial cells. We examined three cell lines (CHO, HeLa, V79) and primary cultured normal rat parenchymal hepatocytes to determine the effect of HGF on radiation response. HGF diminished survival of CHO and V79 cells determined by colony formation assay, whereas no significant change of survival was found in HeLa cells. No synergistic changes of survival were found when these three cell lines were irradiated with the addition of HGF. Thus, HGF did not enhance the radiation effect. We also analyzed the impact of irradiation with HGF on primary cultured normal rat parenchymal hepatocytes. At first, the release of glutamic-oxaloacetic amino-transaminase (GOT) in the supernatant was estimated. Irradiation (40 Gy) with or without HGF did not change GOT release in acute phase by 4 days after irradiation compared with the unirradiated control. Second, the DNA synthesis of rat parenchymal hepatocytes was analyzed using radioactive iodine-labeled deoxyuridine incorporation. HGF counteracted the suppression of DNA synthesis induced by irradiation. Thus, HGF may act as a mitogen even for irradiation-damaged normal cells. (author)

  7. Extracellular matrix components influence DNA synthesis of rat hepatocytes in primary culture

    International Nuclear Information System (INIS)

    Sawada, N.; Tomomura, A.; Sattler, C.A.; Sattler, G.L.; Kleinman, H.K.; Pitot, H.C.

    1986-01-01

    The effects of several extracellular matrix components (EMCs) - fibronectin (Fn), laminin (Ln), type I (C-I) and type IV (C-IV) collagen - on DNA synthesis in rat hepatocytes in primary culture were examined by both quantitative scintillation spectrometry and autoradiography of [ 3 H]thymidine incorporation. Hepatocytes cultured on Fn showed the most active DNA synthesis initiated by epidermal growth factor (EGF) with decreasing levels of [ 3 H]thymidine uptake exhibited in the cell cultured on C-IV, C-I, and Ln, respectively. The decreasing level of DNA synthesis in hepatocytes cultured on Fn, C-IV, C-I, and Ln respectively was not influenced by cell density. The number of EGF receptors of hepatocytes was also not influenced by EMCs. These data suggest that EMCs modify hepatocyte DNA synthesis by means of post-EGF-receptor mechanisms which are regulated by both growth factors and cell density

  8. THE LIVER OF WOODCHUCKS CHRONICALLY INFECTED WITH THE WOODCHUCK HEPATITIS VIRUS CONTAINS FOCI OF VIRUS CORE ANTIGEN NEGATIVE HEPATOCYTES WITH BOTH ALTERED AND NORMAL MORPHOLOGY

    Science.gov (United States)

    Xu, Chunxiao; Yamamoto, Toshiki; Zhou, Tianlun; Aldrich, Carol E.; Frank, Katy; Cullen, John M.; Jilbert, Allison R.; Mason, William S.

    2007-01-01

    The livers of woodchucks chronically infected with woodchuck hepatitis virus (WHV) contain foci of morphologically altered hepatocytes (FAH) with “basophilic”, “amphophilic” and “clear cell” phenotypes, which are possibly pre-neoplastic in nature. Interestingly, most fail to express detectable levels of WHV proteins and nucleic acids. We studied sections of WHV-infected liver tissue to determine if all foci of hepatocytes that failed to express detectable levels of WHV, as assessed by immunoperoxidase staining for WHV core antigen, could be classified morphologically as FAH. We found that at least half of the foci of WHV core antigen negative hepatocytes did not show clear morphological differences in either H&E or PAS (periodic acid Schiff) stained sections from surrounding hepatocytes, and were therefore not designated as FAH. In the second approach, we assayed core antigen negative foci for the presence of fetuin B, a serum protein produced by normal hepatocytes, but not by neoplastic hepatocytes in hepatocellular carcinomas. Basophilic and amphophilic FAH had reduced levels of fetuin B compared to hepatocytes present in the surrounding liver; fetuin B staining was detected in clear cell FAH but the level could not be accurately assessed because of the displacement of fetuin B to the cell periphery by accumulated glycogen. The foci of morphologically normal WHV core antigen negative hepatocytes had similar levels of fetuin B to that of the surrounding hepatocytes. The co-existence of at least four types of WHV core antigen negative foci, including those with no obvious morphologic changes, raises the possibility that the different foci arise from distinct primary events. We hypothesize that a common event is loss of the ability to express WHV, allowing these hepatocytes to escape immune mediated cell death and to undergo clonal expansion to form distinct foci. PMID:17078989

  9. Differential Impacts of Soybean and Fish Oils on Hepatocyte Lipid Droplet Accumulation and Endoplasmic Reticulum Stress in Primary Rabbit Hepatocytes

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    Xueping Zhu

    2016-01-01

    Full Text Available Parenteral nutrition-associated liver disease (PNALD is a severe ailment associated with long-term parenteral nutrition. Soybean oil-based lipid emulsions (SOLE are thought to promote PNALD development, whereas fish oil-based lipid emulsions (FOLE are thought to protect against PNALD. This study aimed to investigate the effects of SOLE and FOLE on primary rabbit hepatocytes. The results reveal that SOLE caused significant endoplasmic reticulum (ER and mitochondrial damage, ultimately resulting in lipid droplets accumulation and ER stress. While these deleterious events induce hepatocyte injury, FOLE at high doses cause only minor ER and mitochondrial damage, which has no effect on hepatic function. SOLE also significantly upregulated glucose-regulated protein 94 mRNA and protein expression. These data indicate that SOLE, but not FOLE, damage the ER and mitochondria, resulting in lipid droplets accumulation and ER stress and, finally, hepatocyte injury. This likely contributes to the differential impacts of SOLE and FOLE on PNALD development and progression.

  10. Metabolism of lipoproteins by human fetal hepatocytes

    International Nuclear Information System (INIS)

    Carr, B.R.

    1987-01-01

    The rate of clearance of lipoproteins from plasma appears to play a role in the development of atherogenesis. The liver may account for as much as two thirds of the removal of low-density lipoprotein and one third of the clearance of high-density lipoprotein in certain animal species and humans, mainly by receptor-mediated pathways. The purpose of the present investigation was to determine if human fetal hepatocytes maintained in vitro take up and degrade lipoproteins. We first determined that the maximal binding capacity of iodine 125-iodo-LDL was approximately 300 ng of low-density lipoprotein protein/mg of membrane protein and an apparent dissociation constant of approximately 60 micrograms low-density lipoprotein protein/ml in membranes prepared from human fetal liver. We found that the maximal uptake of [ 125 I]iodo-LDL and [ 125 I]iodo-HDL by fetal hepatocytes occurred after 12 hours of incubation. Low-density lipoprotein uptake preceded the appearance of degradation products by 4 hours, and thereafter the degradation of low-density lipoprotein increased linearly for at least 24 hours. In contrast, high-density lipoprotein was not degraded to any extent by fetal hepatocytes. [ 125 I]Iodo-LDL uptake and degradation were inhibited more than 75% by preincubation with low-density lipoprotein but not significantly by high-density lipoprotein, whereas [ 125 I]iodo-HDL uptake was inhibited 70% by preincubation with high-density lipoprotein but not by low-density lipoprotein. In summary, human fetal hepatocytes take up and degrade low-density lipoprotein by a receptor-mediated process similar to that described for human extrahepatic tissues

  11. Assessment of the role of in situ generated (E)-2,4-diene-valproic acid in the toxicity of valproic acid and (E)-2-ene-valproic acid in sandwich-cultured rat hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Surendradoss, Jayakumar; Chang, Thomas K.H.; Abbott, Frank S., E-mail: frank.abbott@ubc.ca

    2012-11-01

    Valproic acid (VPA) undergoes cytochrome P450-mediated desaturation to form 4-ene-VPA, which subsequently yields (E)-2,4-diene-VPA by β-oxidation. Another biotransformation pathway involves β-oxidation of VPA to form (E)-2-ene-VPA, which also generates (E)-2,4-diene-VPA by cytochrome P450-mediated desaturation. Although the synthetic form of (E)-2,4-diene-VPA is more hepatotoxic than VPA as shown in various experimental models, there is no conclusive evidence to implicate the in situ generated (E)-2,4-diene-VPA in VPA hepatotoxicity. The present study investigated the effects of modulating the in situ formation of (E)-2,4-diene-VPA on markers of oxidative stress (formation of 2′,7′-dichlorofluorescein; DCF), steatosis (accumulation of BODIPY 558/568 C{sub 12}), necrosis (release of lactate dehydrogenase; LDH), and on cellular total glutathione (GSH) levels in sandwich-cultured rat hepatocytes treated with VPA or (E)-2-ene-VPA. Treatment with either of these chemicals alone increased each of the toxicity endpoints. In VPA-treated hepatocytes, (E)-2,4-diene-VPA was detected only at trace levels, even after phenobarbital (PB) pretreatment and there was no effect on the toxicity of VPA. Furthermore, pretreatment with a cytochrome P450 enzyme inhibitor, 1-aminobenzotriazole (1-ABT), did not influence the extent of VPA toxicity in both PB-pretreated and vehicle-pretreated hepatocytes. However, in (E)-2-ene-VPA-treated hepatocytes, PB pretreatment greatly enhanced the levels of (E)-2,4-diene-VPA and this was accompanied by a further enhancement of the effects of (E)-2-ene-VPA on DCF formation, BODIPY accumulation, LDH release, and GSH depletion. Pretreatment with 1-ABT reduced the concentrations of (E)-2,4-diene-VPA and the extent of (E)-2-ene-VPA toxicity; however, this occurred in PB-pretreated hepatocytes, but not in control hepatocytes. In conclusion, in situ generated (E)-2,4-diene-VPA is not responsible for the hepatocyte toxicity of VPA, whereas it

  12. Lipopolysaccharide stimulates p62-dependent autophagy-like aggregate clearance in hepatocytes.

    Science.gov (United States)

    Chen, Christine; Deng, Meihong; Sun, Qian; Loughran, Patricia; Billiar, Timothy R; Scott, Melanie J

    2014-01-01

    Impairment of autophagy has been associated with liver injury. TLR4-stimulation by LPS upregulates autophagy in hepatocytes, although the signaling pathways involved remain elusive. The objective of this study was to determine the signaling pathway leading to LPS-stimulated autophagy in hepatocytes. Cell lysates from livers of wild type (WT; C57BL/6) mice given LPS (5 mg/kg-IP) and hepatocytes from WT, TLR4ko, and MyD88ko mice treated with LPS (100 ng/mL) up to 24 h were collected. LC3II, p62/SQSTM1, Nrf2, and beclin1 levels were determined by immunoblot, immunofluorescence, and qPCR. Autophagy-like activation was measured by GFP-LC3-puncta formation and LC3II-expression. Beclin1, Nrf2, p62, MyD88, and TIRAP were knocked-down using siRNA. LC3II-expression increased in both liver and hepatocytes after LPS and was dependent on TLR4. Beclin1 expression did not increase after LPS in hepatocytes and beclin1-knockdown did not affect LC3II levels. In hepatocytes given LPS, expression of p62 increased and p62 colocalized with LC3. p62-knockdown prevented LC3II puncta formation. LPS-induced LC3II/p62-puncta also required MyD88/TIRAP signaling and localization of both Nrf2 and NF κ B transcription factors to the nucleus to upregulate p62-expression. Therefore, TLR4-activation by LPS in hepatocytes induces a p62-mediated, not beclin1-mediated, autophagy-like clearance pathway that is hepatoprotective by clearing aggregate-prone or misfolded proteins from the cytosol and preserving energy homeostasis under stress.

  13. Concerted evolution of body mass and cell size: similar patterns among species of birds (Galliformes) and mammals (Rodentia)

    Science.gov (United States)

    Dragosz-Kluska, Dominika; Pis, Tomasz; Pawlik, Katarzyna; Kapustka, Filip; Kilarski, Wincenty M.; Kozłowski, Jan

    2018-01-01

    ABSTRACT Cell size plays a role in body size evolution and environmental adaptations. Addressing these roles, we studied body mass and cell size in Galliformes birds and Rodentia mammals, and collected published data on their genome sizes. In birds, we measured erythrocyte nuclei and basal metabolic rates (BMRs). In birds and mammals, larger species consistently evolved larger cells for five cell types (erythrocytes, enterocytes, chondrocytes, skin epithelial cells, and kidney proximal tubule cells) and evolved smaller hepatocytes. We found no evidence that cell size differences originated through genome size changes. We conclude that the organism-wide coordination of cell size changes might be an evolutionarily conservative characteristic, and the convergent evolutionary body size and cell size changes in Galliformes and Rodentia suggest the adaptive significance of cell size. Recent theory predicts that species evolving larger cells waste less energy on tissue maintenance but have reduced capacities to deliver oxygen to mitochondria and metabolize resources. Indeed, birds with larger size of the abovementioned cell types and smaller hepatocytes have evolved lower mass-specific BMRs. We propose that the inconsistent pattern in hepatocytes derives from the efficient delivery system to hepatocytes, combined with their intense involvement in supracellular function and anabolic activity. PMID:29540429

  14. Concerted evolution of body mass and cell size: similar patterns among species of birds (Galliformes and mammals (Rodentia

    Directory of Open Access Journals (Sweden)

    Marcin Czarnoleski

    2018-04-01

    Full Text Available Cell size plays a role in body size evolution and environmental adaptations. Addressing these roles, we studied body mass and cell size in Galliformes birds and Rodentia mammals, and collected published data on their genome sizes. In birds, we measured erythrocyte nuclei and basal metabolic rates (BMRs. In birds and mammals, larger species consistently evolved larger cells for five cell types (erythrocytes, enterocytes, chondrocytes, skin epithelial cells, and kidney proximal tubule cells and evolved smaller hepatocytes. We found no evidence that cell size differences originated through genome size changes. We conclude that the organism-wide coordination of cell size changes might be an evolutionarily conservative characteristic, and the convergent evolutionary body size and cell size changes in Galliformes and Rodentia suggest the adaptive significance of cell size. Recent theory predicts that species evolving larger cells waste less energy on tissue maintenance but have reduced capacities to deliver oxygen to mitochondria and metabolize resources. Indeed, birds with larger size of the abovementioned cell types and smaller hepatocytes have evolved lower mass-specific BMRs. We propose that the inconsistent pattern in hepatocytes derives from the efficient delivery system to hepatocytes, combined with their intense involvement in supracellular function and anabolic activity.

  15. DNA synthesis in periportal and perivenous hepatocytes of intact and hepatectomized young mice.

    Science.gov (United States)

    Fernández-Blanco, A; Inda, A M; Errecalde, A L

    2015-01-01

    DNA synthesis of hepatocytes in two areas of Intact and Hepatectomized young mice liver along a circadian period was studied. DNA synthesis was significantly different at all analyzed time points in Intact and Hepatectomized animals. Differences between periportal and perivenous hepatocytes were found in hepatectomized animals at 04/42 and 08/46 hr of day/hour post-hepatectomy. DNAs peak in periportal hepatocytes regenerating liver occurs 4 hr earlier than in perivenous hepatocytes, probably reflecting their shorter G1 phase. Besides, daily mean values of regenerating livers were higher than those observed in Intact animals, as a consequence of surgical removal.

  16. Induction of hepatocyte polyploidization in rats of different age by ionizing radiation of different LET

    International Nuclear Information System (INIS)

    Gil'yano, N.Ya.; Malinovskij, O.V.; Khair, M.B.

    1992-01-01

    A decrease in the effectiveness of neutron-irradiation with respect to fusion of nonproliferating hepatocytes of animals with age was shown by the method of flow cytometry. There was an inverse relationship between the effectiveness of induction of non-proliferating hepatocytes fusion and neutron energy. The process of hepatocyte fusion induced by neutrons was inhibited by uranyl acetate. No age-dependent changes were noted in the induction of polyploidization of proliferating hepatocytes by sparsely ionizing radiation. A hypothesis is proposed concerning a membrane nature of the target responsible for hepatocyte polyploidization induced by densely ionizing radiation. (authors). 8 refs., 4 figs., 5 tabs

  17. Induction of hepatocyte polyploidization in rats of different age by ionizing radiation of different LET

    International Nuclear Information System (INIS)

    Gil'yano, N.Ya.; Malinovskij, O.V.; Khair, M.B.

    1990-01-01

    A decrease in the effectiveness of neutron-irradiation with respect to fusion of nonproliferating hepatocytes of animals with age was shown by the method of flow cytometry. There was an inverse relationship between the effectiveness of induction of non-proliferating hepatocytes fusion and neutron energy. The process of hepatocyte fusion induced by neutrons was inhibited by uranyl acetate. No age-dependent changes were noted in the induction of polyploidization of proliferating hepatocytes by sparsely ionizing radiation. A hypothesis is proposed concerning a membrane nature of the target responsible for hepatocyte polyploidization induced by densely ionizing radiation

  18. Hepatocyte transplantation and advancements in alternative cell sources for liver-based regenerative medicine.

    Science.gov (United States)

    Lee, Charlotte A; Sinha, Siddharth; Fitzpatrick, Emer; Dhawan, Anil

    2018-06-01

    Human hepatocyte transplantation has been actively perused as an alternative to liver replacement for acute liver failure and liver-based metabolic defects. Current challenges in this field include a limited cell source, reduced cell viability following cryopreservation and poor engraftment of cells into the recipient liver with consequent limited life span. As a result, alternative stem cell sources such as pluripotent stem cells, fibroblasts, hepatic progenitor cells, amniotic epithelial cells and mesenchymal stem/stromal cells (MSCs) can be used to generate induced hepatocyte like cells (HLC) with each technique exhibiting advantages and disadvantages. HLCs may have comparable function to primary human hepatocytes and could offer patient-specific treatment. However, long-term functionality of transplanted HLCs and the potential oncogenic risks of using stem cells have yet to be established. The immunomodulatory effects of MSCs are promising, and multiple clinical trials are investigating their effect in cirrhosis and acute liver failure. Here, we review the current status of hepatocyte transplantation, alternative cell sources to primary human hepatocytes and their potential in liver regeneration. We also describe recent clinical trials using hepatocytes derived from stem cells and their role in improving the phenotype of several liver diseases.

  19. Unrestricted Hepatocyte Transduction with Adeno-Associated Virus Serotype 8 Vectors in Mice

    Science.gov (United States)

    Nakai, Hiroyuki; Fuess, Sally; Storm, Theresa A.; Muramatsu, Shin-ichi; Nara, Yuko; Kay, Mark A.

    2005-01-01

    Recombinant adeno-associated virus (rAAV) vectors can mediate long-term stable transduction in various target tissues. However, with rAAV serotype 2 (rAAV2) vectors, liver transduction is confined to only a small portion of hepatocytes even after administration of extremely high vector doses. In order to investigate whether rAAV vectors of other serotypes exhibit similar restricted liver transduction, we performed a dose-response study by injecting mice with β-galactosidase-expressing rAAV1 and rAAV8 vectors via the portal vein. The rAAV1 vector showed a blunted dose-response similar to that of rAAV2 at high doses, while the rAAV8 vector dose-response remained unchanged at any dose and ultimately could transduce all the hepatocytes at a dose of 7.2 × 1012 vector genomes/mouse without toxicity. This indicates that all hepatocytes have the ability to process incoming single-stranded vector genomes into duplex DNA. A single tail vein injection of the rAAV8 vector was as efficient as portal vein injection at any dose. In addition, intravascular administration of the rAAV8 vector at a high dose transduced all the skeletal muscles throughout the body, including the diaphragm, the entire cardiac muscle, and substantial numbers of cells in the pancreas, smooth muscles, and brain. Thus, rAAV8 is a robust vector for gene transfer to the liver and provides a promising research tool for delivering genes to various target organs. In addition, the rAAV8 vector may offer a potential therapeutic agent for various diseases affecting nonhepatic tissues, but great caution is required for vector spillover and tight control of tissue-specific gene expression. PMID:15596817

  20. Functional properties of hepatocytes in vitro are correlated with cell polarity maintenance.

    Science.gov (United States)

    Zeigerer, Anja; Wuttke, Anne; Marsico, Giovanni; Seifert, Sarah; Kalaidzidis, Yannis; Zerial, Marino

    2017-01-01

    Exploring the cell biology of hepatocytes in vitro could be a powerful strategy to dissect the molecular mechanisms underlying the structure and function of the liver in vivo. However, this approach relies on appropriate in vitro cell culture systems that can recapitulate the cell biological and metabolic features of the hepatocytes in the liver whilst being accessible to experimental manipulations. Here, we adapted protocols for high-resolution fluorescence microscopy and quantitative image analysis to compare two primary hepatocyte culture systems, monolayer and collagen sandwich, with respect to the distribution of two distinct populations of early endosomes (APPL1 and EEA1-positive), endocytic capacity, metabolic and signaling activities. In addition to the re-acquisition of hepatocellular polarity, primary hepatocytes grown in collagen sandwich but not in monolayer culture recapitulated the apico-basal distribution of EEA1 endosomes observed in liver tissue. We found that such distribution correlated with the organization of the actin cytoskeleton in vitro and, surprisingly, was dependent on the nutritional state in vivo. Hepatocytes in collagen sandwich also exhibited faster kinetics of low-density lipoprotein (LDL) and epidermal growth factor (EGF) internalization, showed improved insulin sensitivity and preserved their ability for glucose production, compared to hepatocytes in monolayer cultures. Although no in vitro culture system can reproduce the exquisite structural features of liver tissue, our data nevertheless highlight the ability of the collagen sandwich system to recapitulate key structural and functional properties of the hepatocytes in the liver and, therefore, support the usage of this system to study aspects of hepatocellular biology in vitro. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  1. A fat option for the pig: Hepatocytic differentiated mesenchymal stem cells for translational research

    Energy Technology Data Exchange (ETDEWEB)

    Brückner, Sandra, E-mail: sandra.brueckner@medizin.uni-leipzig.de [University Hospital Leipzig, Department of Visceral, Transplantation, Thoracic and Vascular Surgery, Liebigstraße 21, Leipzig D-04103 (Germany); Tautenhahn, Hans-Michael, E-mail: hans-michael.tautenhahn@medizin.uni-leipzig.de [University Hospital Leipzig, Department of Visceral, Transplantation, Thoracic and Vascular Surgery, Liebigstraße 21, Leipzig D-04103 (Germany); TRM, Translational Centre for Regenerative Medicine, Philipp-Rosenthal-Str. 55, Leipzig D-04103 (Germany); Winkler, Sandra, E-mail: sandra.pelz@medizin.uni-leipzig.de [University Hospital Leipzig, Department of Visceral, Transplantation, Thoracic and Vascular Surgery, Liebigstraße 21, Leipzig D-04103 (Germany); Stock, Peggy, E-mail: peggy.stock@medizin.uni-leipzig.de [University Hospital Leipzig, Department of Visceral, Transplantation, Thoracic and Vascular Surgery, Liebigstraße 21, Leipzig D-04103 (Germany); Dollinger, Matthias, E-mail: matthias.dollinger@uniklinik-ulm.de [University Hospital Ulm, First Department of Medicine, Albert-Einstein-Allee 23, Ulm D-89081 (Germany); Christ, Bruno, E-mail: bruno.christ@medizin.uni-leipzig.de [University Hospital Leipzig, Department of Visceral, Transplantation, Thoracic and Vascular Surgery, Liebigstraße 21, Leipzig D-04103 (Germany); TRM, Translational Centre for Regenerative Medicine, Philipp-Rosenthal-Str. 55, Leipzig D-04103 (Germany)

    2014-02-15

    Study background: Extended liver resection is the only curative treatment option of liver cancer. Yet, the residual liver may not accomplish the high metabolic and regenerative capacity needed, which frequently leads to acute liver failure. Because of their anti-inflammatory and -apoptotic as well as pro-proliferative features, mesenchymal stem cells differentiated into hepatocyte-like cells might provide functional and regenerative compensation. Clinical translation of basic research requires pre-clinical approval in large animals. Therefore, we characterized porcine mesenchymal stem cells (MSC) from adipose tissue and bone marrow and their hepatocyte differentiation potential for future assessment of functional liver support after surgical intervention in the pig model. Methods: Mesenchymal surface antigens and multi-lineage differentiation potential of porcine MSC isolated by collagenase digestion either from bone marrow or adipose tissue (subcutaneous/visceral) were assessed by flow cytometry. Morphology and functional properties (urea-, glycogen synthesis and cytochrome P450 activity) were determined during culture under differentiation conditions and compared with primary porcine hepatocytes. Results: MSC from porcine adipose tissue and from bone marrow express the typical mesenchymal markers CD44, CD29, CD90 and CD105 but not haematopoietic markers. MSC from both sources displayed differentiation into the osteogenic as well as adipogenic lineage. After hepatocyte differentiation, expression of CD105 decreased significantly and cells adopted the typical polygonal morphology of hepatocytes. Glycogen storage was comparable in adipose tissue- and bone marrow-derived cells. Urea synthesis was about 35% lower in visceral than in subcutaneous adipose tissue-derived MSC. Cytochrome P450 activity increased significantly during differentiation and was twice as high in hepatocyte-like cells generated from bone marrow as from adipose tissue. Conclusion: The hepatocyte

  2. A fat option for the pig: Hepatocytic differentiated mesenchymal stem cells for translational research

    International Nuclear Information System (INIS)

    Brückner, Sandra; Tautenhahn, Hans-Michael; Winkler, Sandra; Stock, Peggy; Dollinger, Matthias; Christ, Bruno

    2014-01-01

    Study background: Extended liver resection is the only curative treatment option of liver cancer. Yet, the residual liver may not accomplish the high metabolic and regenerative capacity needed, which frequently leads to acute liver failure. Because of their anti-inflammatory and -apoptotic as well as pro-proliferative features, mesenchymal stem cells differentiated into hepatocyte-like cells might provide functional and regenerative compensation. Clinical translation of basic research requires pre-clinical approval in large animals. Therefore, we characterized porcine mesenchymal stem cells (MSC) from adipose tissue and bone marrow and their hepatocyte differentiation potential for future assessment of functional liver support after surgical intervention in the pig model. Methods: Mesenchymal surface antigens and multi-lineage differentiation potential of porcine MSC isolated by collagenase digestion either from bone marrow or adipose tissue (subcutaneous/visceral) were assessed by flow cytometry. Morphology and functional properties (urea-, glycogen synthesis and cytochrome P450 activity) were determined during culture under differentiation conditions and compared with primary porcine hepatocytes. Results: MSC from porcine adipose tissue and from bone marrow express the typical mesenchymal markers CD44, CD29, CD90 and CD105 but not haematopoietic markers. MSC from both sources displayed differentiation into the osteogenic as well as adipogenic lineage. After hepatocyte differentiation, expression of CD105 decreased significantly and cells adopted the typical polygonal morphology of hepatocytes. Glycogen storage was comparable in adipose tissue- and bone marrow-derived cells. Urea synthesis was about 35% lower in visceral than in subcutaneous adipose tissue-derived MSC. Cytochrome P450 activity increased significantly during differentiation and was twice as high in hepatocyte-like cells generated from bone marrow as from adipose tissue. Conclusion: The hepatocyte

  3. 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.

  4. The evolution of the adult body form of the crested newt (Triturus cristatus superspecies, Caudata, Salamandridae)

    NARCIS (Netherlands)

    Vukov, T.D.; Sotiropoulos, K.; Wielstra, B.M.; Dzukic, G.; Kalezic, M.

    2011-01-01

    We characterized the adult body form of the crested newt (Triturus cristatus superspecies) and explored its evolution. From seven morphometric traits, we determined that body size, interlimb distance and head width define the body form. None of the morphometric traits showed a phylogenetic signal.

  5. Angiotensin II protects primary rat hepatocytes against bile salt-induced apoptosis.

    Directory of Open Access Journals (Sweden)

    Golnar Karimian

    Full Text Available UNLABELLED: Angiotensin II (AT-II is a pro-fibrotic compound that acts via membrane-bound receptors (AT-1R/AT-2R and thereby activates hepatic stellate cells (HSCs. AT-II receptor blockers (ARBs are thus important candidates in the treatment of liver fibrosis. However, multiple case reports suggest that AT-1R blockers may induce hepatocyte injury. Therefore, we investigated the effect of AT-II and its receptor blockers on cytokine-, oxidative stress- and bile salt-induced cell death in hepatocytes. Primary rat hepatocytes were exposed to TNF-α/Actinomycin D, the ROS-generating agent menadione or the bile salts: glycochenodeoxycholic acid (GCDCA and tauro-lithocholic acid-3 sulfate (TLCS, to induce apoptosis. AT-II (100 nmol/L was added 10 minutes prior to the cell death-inducing agent. AT-1R antagonists (Sartans and the AT-2R antagonist PD123319 were used at 1 µmol/L. Apoptosis (caspase-3 activity, acridine orange staining and necrosis (Sytox green staining were quantified. Expression of CHOP (marker for ER stress and AT-II receptor mRNAs were quantified by Q-PCR. AT-II dose-dependently reduced GCDCA-induced apoptosis of hepatocytes (-50%, p<0.05 without inducing necrosis. In addition, AT-II reduced TLCS-induced apoptosis of hepatocytes (-50%, p<0.05. However, AT-II did not suppress TNF/Act-D and menadione-induced apoptosis. Only the AT-1R antagonists abolished the protective effect of AT-II against GCDCA-induced apoptosis. AT-II increased phosphorylation of ERK and a significant reversal of the protective effect of AT-II was observed when signaling kinases, including ERK, were inhibited. Moreover, AT-II prevented the GCDCA-induced expression of CHOP (the marker of the ER-mediated apoptosis. CONCLUSION: Angiotensin II protects hepatocytes from bile salt-induced apoptosis through a combined activation of PI3-kinase, MAPKs, PKC pathways and inhibition of bile salt-induced ER stress. Our results suggest a mechanism for the observed hepatocyte

  6. Stimulation of glucose phosphorylation by fructose in isolated rat hepatocytes.

    Science.gov (United States)

    Van Schaftingen, E; Vandercammen, A

    1989-01-15

    The phosphorylation of glucose was measured by the formation of [3H]H2O from [2-3H]glucose in suspensions of freshly isolated rat hepatocytes. Fructose (0.2 mM) stimulated 2-4-fold the rate of phosphorylation of 5 mM glucose although not of 40 mM glucose, thus increasing the apparent affinity of the glucose phosphorylating system. A half-maximal stimulatory effect was observed at about 50 microM fructose. Stimulation was maximal 5 min after addition of the ketose and was stable for at least 40 min, during which period 60% of the fructose was consumed. The effect of fructose was reversible upon removal of the ketose. Sorbitol and tagatose were as potent as fructose in stimulating the phosphorylation of 5 mM glucose. D-Glyceraldehyde also had a stimulatory effect but at tenfold higher concentrations. In contrast, dihydroxyacetone had no significant effect and glycerol inhibited the detritiation of glucose. Oleate did not affect the phosphorylation of glucose, even in the presence of fructose, although it stimulated the formation of ketone bodies severalfold, indicating that it was converted to its acyl-CoA derivative. These results allow the conclusion that fructose stimulates glucokinase in the intact hepatocyte. They also suggest that this effect is mediated through the formation of fructose 1-phosphate, which presumably interacts with a competitive inhibitor of glucokinase other than long-chain acyl-CoAs.

  7. Rapid and sensitive measure of gluconeogenesis in isolated bovine hepatocytes

    International Nuclear Information System (INIS)

    Azain, M.J.; Kasser, T.R.; Atwell, C.A.; Baile, C.A.

    1986-01-01

    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 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 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 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

  8. Biotransformation of hydralazine (HDZ) in monolayer cultures of rabbit hepatocytes

    International Nuclear Information System (INIS)

    McQueen, C.A.; Rosado, R.R.

    1990-01-01

    Adverse reactions to HDZ have been associated with the acetylator polymorphism; slow acetylators are more likely to develop HDZ-induced lupus erythematosus. In studying the role of this polymorphism in susceptibility to HDZ toxicity, the biotransformation of HDZ was investigated in rabbit hepatocytes. New Zealand white rabbits, like humans, are classified as rapid or slow acetylators. Heptocytes were isolated from rapid acetylator rabbits by collagenase perfusion. Monolayer cultures were initiated and exposed to 14 C-HDZ. Since HDZ is unstable at neutral pH, parallel incubations were done in the absence of cells. Metabolites in the media were determined by reverse phase HPLC. Phthalazine (P), phthalazinone (PZ), triazoloph-thalazine (TP), methyl TP (MTP) and 3-hydroxy MTP were identified. In the absence of cells, more TP was formed than MTP, probably resulting from reaction of HDZ with components in the medium. In the presence of cells, there was a three-fold increase in MTP, while the amount of TP was relatively constant. Only trace amounts of P, PZ 3-hydroxy MTP were detected. These data indicate that monolayer cultures of rapid acetylator rabbit hepatocytes were capable of metabolizing HDZ with acetylation playing a major role. These studies are being extended to cells from slow acetylator rabbits

  9. ß-Hydroxybutyrate Activates the NF-κB Signaling Pathway to Promote the Expression of Pro-Inflammatory Factors in Calf Hepatocytes

    Directory of Open Access Journals (Sweden)

    Xiaoxia Shi

    2014-01-01

    Full Text Available Background/Aims: ß-hydroxybutyrate (BHBA is the major component of ketone bodies in ketosis. Dairy cows with ketosis often undergo oxidative stress. BHBA is related to the inflammation involved in other diseases of dairy cattle. However, whether BHBA can induce inflammatory injury in dairy cow hepatocytes and the potential mechanism of this induction are not clear. The NF-κB pathway plays a vital role in the inflammatory response. Methods: Therefore, this study evaluated the oxidative stress, pro-inflammatory factors and NF-κB pathway in cultured calf hepatocytes treated with different concentrations of BHBA, pyrrolidine dithiocarbamate (PDTC, an NF-κB pathway inhibitor and N-acetylcysteine (NAC, antioxidant. Results: The results showed that BHBA could significantly increase the levels of oxidation indicators (MDA, NO and iNOS, whereas the levels of antioxidation indicators (GSH-Px, CAT and SOD were markedly decreased in hepatocytes. The IKKß activity and phospho-IκBa (p-IκBa contents were increased in BHBA-treated hepatocytes. This increase was accompanied by the increased expression level and transcription activity of p65. The expression levels of NF-κB-regulated inflammatory cytokines, namely TNF-a, IL-6 and IL-1ß, were markedly increased after BHBA treatment, while significantly decreased after NAC treatment. However, the p-IκBa level and the expression and activity of p65 and its target genes were markedly decreased in the PDTC + BHBA group compared with the BHBA (1.8 mM group. Moreover, immunocytofluorescence of p65 showed a similar trend. Conclusion: The present data indicate that higher concentrations of BHBA can induce cattle hepatocyte inflammatory injury through the NF-κB signaling pathway, which may be activated by oxidative stress.

  10. The time point of β-catenin knockout in hepatocytes determines their response to xenobiotic activation of the constitutive androstane receptor

    International Nuclear Information System (INIS)

    Ganzenberg, Katrin; Singh, Yasmin; Braeuning, Albert

    2013-01-01

    The constitutive androstane receptor (CAR) controls the expression of drug-metabolizing enzymes and regulates hepatocyte proliferation. Studies with transgenic mice with an early postnatal conditional hepatocyte-specific knockout of the β-catenin gene Ctnnb1 revealed that β-catenin deficiency decreases the magnitude of induction of drug-metabolizing enzymes by CAR activators, abrogates zonal differences in the hepatocytes’ susceptibility to these compounds, and impacts on hepatocyte proliferation. These data, however, do not allow distinguishing between effects caused by β-catenin deficiency during postnatal liver development and acute effects of β-catenin deficiency in the adult animal at the time point of CAR activation. Therefore, CAR activation was now studied in a different mouse model allowing for the hepatocyte-specific knockout of β-catenin in adult mice. Treatment of these mice with 3 mg/kg body weight of the model CAR activator 1,4-bis-[2-(3,5-dichloropyridyloxy)]benzene (TCPOBOP) confirmed previous findings related to the coordinate regulation of drug metabolism by β-catenin and CAR. More importantly, the present study clarified that the impact of β-catenin signaling on CAR-mediated enzyme induction in the liver is not merely due to developmental defects caused by a postnatal lack of β-catenin, but depends on the presence of β-catenin at the time point of xenobiotic treatment. The study also revealed interesting differences between the two mouse models: hepatic zonation of TCPOBOP-dependent induction of drug-metabolizing enzymes was restored in mice with late knockout of β-catenin, and the strong proliferative response of female mice was exclusively abolished when using animals with a late β-catenin knockout. This suggests a β-catenin-dependent postnatal priming of hepatocytes during postnatal liver development, later affecting the proliferative response of adult animals to CAR-activating xenobiotics

  11. DIFFERENCES IN PROPIONATE-INDUCED INHIBITION OF CHOLESTEROL AND TRIACYLGLYCEROL SYNTHESIS BETWEEN HUMAN AND RAT HEPATOCYTES IN PRIMARY CULTURE

    NARCIS (Netherlands)

    LIN, YG; VONK, RJ; SLOOFF, MJH; KUIPERS, F; SMIT, MJ

    Propionate is a short-chain fatty acid formed in the colon and supposedly involved in the cholesterol-lowering effect of soluble fibre. To explore the underlying mechanism(s) of this fibre action, we have used human hepatocytes in primary culture to study the effects of propionate on hepatic lipid

  12. DISTINCT FUNCTIONS OF JNK AND C-JUN IN OXIDANT-INDUCED HEPATOCYTE DEATH

    Science.gov (United States)

    Amir, Muhammad; Liu, Kun; Zhao, Enpeng; Czaja, Mark J.

    2013-01-01

    Overactivation of c-Jun N-terminal kinase (JNK)/c-Jun signaling is a central mechanism of hepatocyte injury and death including that from oxidative stress. However, the functions of JNK and c-Jun are still unclear, and this pathway also inhibits hepatocyte death. Previous studies of menadione-induced oxidant stress demonstrated that toxicity resulted from sustained JNK/c-Jun activation as death was blocked by the c-Jun dominant negative TAM67. To further delineate the function of JNK/c-Jun signaling in hepatocyte injury from oxidant stress, the effects of direct JNK inhibition on menadione-induced death were examined. In contrast to the inhibitory effect of TAM67, pharmacological JNK inhibition by SP600125 sensitized the rat hepatocyte cell line RALA255-10G to death from menadione. SP600125 similarly sensitized mouse primary hepatocytes to menadione toxicity. Death from SP600125/menadione was c-Jun dependent as it was blocked by TAM67, but independent of c-Jun phosphorylation. Death occurred by apoptosis and necrosis and activation of the mitochondrial death pathway. Short hairpin RNA knockdowns of total JNK or JNK2 sensitized to death from menadione, whereas a jnk1 knockdown was protective. Jnk2 null mouse primary hepatocytes were also sensitized to menadione death. JNK inhibition magnified decreases in cellular ATP content and β-oxidation induced by menadione. This effect mediated cell death as chemical inhibition of β-oxidation also sensitized cells to death from menadione, and supplementation with the β-oxidation substrate oleate blocked death. Components of the JNK/c-Jun signaling pathway have opposing functions in hepatocyte oxidant stress with JNK2 mediating resistance to cell death and c-Jun promoting death. PMID:22644775

  13. β-Adrenergic induction of lipolysis in hepatocytes is inhibited by ethanol exposure.

    Science.gov (United States)

    Schott, Micah B; Rasineni, Karuna; Weller, Shaun G; Schulze, Ryan J; Sletten, Arthur C; Casey, Carol A; McNiven, Mark A

    2017-07-14

    In liver steatosis ( i.e. fatty liver), hepatocytes accumulate many large neutral lipid storage organelles known as lipid droplets (LDs). LDs are important in the maintenance of energy homeostasis, but the signaling mechanisms that stimulate LD metabolism in hepatocytes are poorly defined. In adipocytes, catecholamines target the β-adrenergic (β-AR)/cAMP pathway to activate cytosolic lipases and induce their recruitment to the LD surface. Therefore, the goal of this study was to determine whether hepatocytes, like adipocytes, also undergo cAMP-mediated lipolysis in response to β-AR stimulation. Using primary rat hepatocytes and human hepatoma cells, we found that treatment with the β-AR agent isoproterenol caused substantial LD loss via activation of cytosolic lipases adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL). β-Adrenergic stimulation rapidly activated PKA, which led to the phosphorylation of ATGL and HSL and their recruitment to the LD surface. To test whether this β-AR-dependent lipolysis pathway was altered in a model of alcoholic fatty liver, primary hepatocytes from rats fed a 6-week EtOH-containing Lieber-DeCarli diet were treated with cAMP agonists. Compared with controls, EtOH-exposed hepatocytes showed a drastic inhibition in β-AR/cAMP-induced LD breakdown and the phosphorylation of PKA substrates, including HSL. This observation was supported in VA-13 cells, an EtOH-metabolizing human hepatoma cell line, which displayed marked defects in both PKA activation and isoproterenol-induced ATGL translocation to the LD periphery. In summary, these findings suggest that β-AR stimulation mobilizes cytosolic lipases for LD breakdown in hepatocytes, and perturbation of this pathway could be a major consequence of chronic EtOH insult leading to fatty liver.

  14. Oxidative stress is involved in Dasatinib-induced apoptosis in rat primary hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Tao; Luo, Peihua; Zhu, Hong; Zhao, Yuqin [Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058 (China); Wu, Honghai; Gai, Renhua; Wu, Youping [Center for Drug Safety Evaluation and Research of Zhejiang University, Hangzhou 310058 (China); Yang, Bo [Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058 (China); Yang, Xiaochun, E-mail: yangxiaochun@zju.edu.cn [Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058 (China); Center for Drug Safety Evaluation and Research of Zhejiang University, Hangzhou 310058 (China); He, Qiaojun, E-mail: qiaojunhe@zju.edu.cn [Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058 (China); Center for Drug Safety Evaluation and Research of Zhejiang University, Hangzhou 310058 (China)

    2012-06-15

    Dasatinib, a multitargeted inhibitor of BCR–ABL and SRC kinases, exhibits antitumor activity and extends the survival of patients with chronic myeloid leukemia (CML) and Philadelphia chromosome-positive acute lymphoblastic leukemia (ALL). However, some patients suffer from hepatotoxicity, which occurs through an unknown mechanism. In the present study, we found that Dasatinib could induce hepatotoxicity both in vitro and in vivo. Dasatinib reduced the cell viability of rat primary hepatocytes, induced the release of alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) in vitro, and triggered the ballooning degeneration of hepatocytes in Sprague–Dawley rats in vivo. Apoptotic markers (chromatin condensation, cleaved caspase-3 and cleaved PARP) were detected to indicate that the injury induced by Dasatinib in hepatocytes in vitro was mediated by apoptosis. This result was further validated in vivo using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assays. Here we found that Dasatinib dramatically increased the level of reactive oxygen species (ROS) in hepatocytes, reduced the intracellular glutathione (GSH) content, attenuated the activity of superoxide dismutase (SOD), generated malondialdehyde (MDA), a product of lipid peroxidation, decreased the mitochondrial membrane potential, and activated nuclear factor erythroid 2-related factor 2 (Nrf2) and mitogen-activated protein kinases (MAPK) related to oxidative stress and survival. These results confirm that oxidative stress plays a pivotal role in Dasatinib-mediated hepatotoxicity. N-acetylcysteine (NAC), a typical antioxidant, can scavenge free radicals, attenuate oxidative stress, and protect hepatocytes against Dasatinib-induced injury. Thus, relieving oxidative stress is a viable strategy for reducing Dasatinib-induced hepatotoxicity. -- Highlights: ►Dasatinib shows potential hepatotoxicity both in vitro and in vivo. ►Apoptosis plays a vital role in Dasatinib

  15. Sexual Abuse of Children as a Form of Power Abuse and Abuse of the Body

    OpenAIRE

    Reynaert, Machteld

    2015-01-01

    This article investigates the relationship between sexual abuse, power and the body from a Catholic theological viewpoint. The article starts with the relationship between sexual abuse and power. It is argued that sexual abuse is always a form of power abuse. A second step examines the relation between sexual abuse and the body. We may not ignore the theme of the body when we speak about sexual abuse as a form of power abuse. The article also explores whether the body is a theme in recent (th...

  16. Determination of metabolic stability using cryopreserved hepatocytes from rainbow trout (Oncorhynchus mykiss)

    Science.gov (United States)

    Standard protocols for isolating, cryopreserving, and thawing rainbow trout hepatocytes are described, along with procedures for using fresh or cryopreserved hepatocytes to assess chemical metabolic stability in fish by means of a substrate depletion approach. Variations on thes...

  17. Evaluation of perfluoroalkyl acid activity using primary mouse and human hepatocytes

    International Nuclear Information System (INIS)

    Rosen, Mitchell B.; Das, Kaberi P.; Wood, Carmen R.; Wolf, Cynthia J.; Abbott, Barbara D.; Lau, Christopher

    2013-01-01

    While perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) have been studied at length, less is known about the biological activity of other perfluoroalkyl acids (PFAAs) detected in the environment. Using a transient transfection assay developed in COS-1 cells, our group has previously evaluated a variety of PFAAs for activity associated with activation of peroxisome proliferator-activated receptor alpha (PPARα). Here we use primary heptatocytes to further assess the biological activity of a similar group of PFAAs using custom designed Taqman Low Density Arrays. Primary mouse and human hepatoyctes were cultured for 48 h in the presence of varying concentrations of 12 different PFAAs or Wy14,643, a known activator of PPARα. Total RNA was collected and the expression of 48 mouse or human genes evaluated. Gene selection was based on either in-house liver microarray data (mouse) or published data using primary hepatocytes (human). Gene expression in primary mouse hepatocytes was more restricted than expected. Genes typically regulated in whole tissue by PPARα agonists were not altered in mouse cells including Acox1, Me1, Acaa1a, Hmgcs1, and Slc27a1. Cyp2b10, a gene regulated by the constitutive androstane receptor and a transcript normally up-regulated by in vivo exposure to PFAAs, was also unchanged in cultured mouse hepatocytes. Cyp4a14, Ehhadh, Pdk4, Cpt1b, and Fabp1 were regulated as expected in mouse cells. A larger group of genes were differentially expressed in human primary hepatocytes, however, little consistency was observed across compounds with respect to which genes produced a significant dose response making the determination of relative biological activity difficult. This likely reflects weaker activation of PPARα in human versus rodent cells as well as variation among individual cell donors. Unlike mouse cells, CYP2B6 was up-regulated in human hepatocytes by a number of PFAAs as was PPARδ. Rankings were conducted on the limited

  18. Bidirectional transport of iminodiacetic organic anion analogues between plasma and hepatocyte

    International Nuclear Information System (INIS)

    Peters, A.M.; Myers, M.J.; Mohammadtaghi, S.; Mubashar, M.; Mathie, R.T.

    1998-01-01

    The kinetics of organic anions are well described and back-diffusion from hepatocyte to plasma is accepted. Although iminodiacetic (IDA) analogues, as organic anions, should also show bidirectional transport between hepatocyte and plasma, this has not been directly demonstrated heretofore. The aim of this study was to directly demonstrate back-diffusion and to quantify it in terms of its fractional rate constant. Kinetics of diethyl IDA were studied in three anaesthetised dogs in which femoral arterial and hepatic venous samples were obtained after injection of tracer into (a) a peripheral vein or (b) hepatic artery or portal vein. Arterial time-concentration curves were also compared between peripheral venous and either hepatic arterial or portal venous injections. Time-activity curves were recorded from regions of interest over the cardiac blood pool and peripheral hepatic parenchyma in 30 patients undergoing routine IDA hepatobiliary imaging with diethyl IDA or mebrofenin and fractional rate constants of clearance of IDA from the hepatocyte compared between compartmental and deconvolution analyses. After peripheral injection in dogs, there was an early arteriovenous concentration gradient across the liver indicating an hepatocyte extraction fraction in the three animals of 0.9, 0.8 and 0.6. The net extraction fraction decreased exponentially over 40 min. Time-concentration curves from hepatic vein and femoral artery were virtually superimposed following intrahepatic injections. Peripheral arterial curves, however, had different shapes according to whether injections were intrahepatic or peripheral, and were consistent with significant back-diffusion. In clinical studies, the blood disappearance curves were fitted as the sum of two exponentials and the liver curves as the difference of two exponentials (with rate constants denoted α 1 h and α 2 h ). Based on compartmental analysis of the blood curves, the sum of the fractional rate constants of tracer movement

  19. Micropatterned co-culture of hepatocyte spheroids layered on non-parenchymal cells to understand heterotypic cellular interactions

    International Nuclear Information System (INIS)

    Otsuka, Hidenori; Sasaki, Kohei; Okimura, Saya; Nagamura, Masako; Nakasone, Yuichi

    2013-01-01

    Microfabrication and micropatterning techniques in tissue engineering offer great potential for creating and controlling cellular microenvironments including cell–matrix interactions, soluble stimuli and cell–cell interactions. Here, we present a novel approach to generate layered patterning of hepatocyte spheroids on micropatterned non-parenchymal feeder cells using microfabricated poly(ethylene glycol) (PEG) hydrogels. Micropatterned PEG-hydrogel-treated substrates with two-dimensional arrays of gelatin circular domains (ϕ = 100 μm) were prepared by photolithographic method. Only on the critical structure of PEG hydrogel with perfect protein rejection, hepatocytes were co-cultured with non-parenchymal cells to be led to enhanced hepatocyte functions. Then, we investigated the mechanism of the functional enhancement in co-culture with respect to the contributions of soluble factors and direct cell–cell interactions. In particular, to elucidate the influence of soluble factors on hepatocyte function, hepatocyte spheroids underlaid with fibroblasts (NIH/3T3 mouse fibroblasts) or endothelial cells (BAECs: bovine aortic endothelial cells) were compared with physically separated co-culture of hepatocyte monospheroids with NIH3T3 or BAEC using trans-well culture systems. Our results suggested that direct heterotypic cell-to-cell contact and soluble factors, both of these between hepatocytes and fibroblasts, significantly enhanced hepatocyte functions. In contrast, direct heterotypic cell-to-cell contact between hepatocytes and endothelial cells only contributed to enhance hepatocyte functions. This patterning technique can be a useful experimental tool for applications in basic science, drug screening and tissue engineering, as well as in the design of artificial liver devices. (paper)

  20. Acidosis-induced downregulation of hepatocyte mitochondrial aquaporin-8 and ureagenesis from ammonia.

    Science.gov (United States)

    Molinas, Sara M; Soria, Leandro R; Marrone, Julieta; Danielli, Mauro; Trumper, Laura; Marinelli, Raúl A

    2015-08-01

    It has been proposed that, during metabolic acidosis, the liver downregulates mitochondrial ammonia detoxification via ureagenesis, a bicarbonate-consuming process. Since we previously demonstrated that hepatocyte mitochondrial aquaporin-8 channels (mtAQP8) facilitate the uptake of ammonia and its metabolism into urea, we studied whether mtAQP8 is involved in the liver adaptive response to acidosis. Primary cultured rat hepatocytes were adapted to acidosis by exposing them to culture medium at pH 7.0 for 40 h. Control cells were exposed to pH 7.4. Hepatocytes exposed to acid medium showed a decrease in mtAQP8 protein expression (-30%, p ammonia was assessed by incubating the cells with (15)N-labeled ammonia and measuring (15)N-labeled urea synthesis by nuclear magnetic resonance. Reduced ureagenesis was found in acidified hepatocytes (-31%, p ammonia in response to acidosis.

  1. Hepatocyte heterogeneity in the metabolism of carbohydrates.

    Science.gov (United States)

    Jungermann, K; Thurman, R G

    1992-01-01

    Periportal and perivenous hepatocytes possess different amounts and activities of the rate-generating enzymes of carbohydrate and oxidative energy metabolism and thus different metabolic capacities. This is the basis of the model of metabolic zonation, according to which periportal cells catalyze predominantly the oxidative catabolism of fatty and amino acids as well as glucose release and glycogen formation via gluconeogenesis, and perivenous cells carry out preferentially glucose uptake for glycogen synthesis and glycolysis coupled to liponeogenesis. The input of humoral and nervous signals into the periportal and perivenous zones is different; gradients of oxygen, substrates and products, hormones and mediators and nerve densities exist which are important not only for the short-term regulation of carbohydrate metabolism but also for the long-term regulation of zonal gene expression. The specialization of periportal and perivenous hepatocytes in carbohydrate metabolism has been well characterized. In vivo evidence is provided by the complex metabolic situation termed the 'glucose paradox' and by zonal flux differences calculated on the basis of the distribution of enzymes and metabolites. In vitro evidence is given by the different flux rates determined with classical invasive techniques, e.g. in periportal-like and perivenous-like hepatocytes in cell culture, in periportal- and perivenous-enriched hepatocyte populations and in perfused livers during orthograde and retrograde flow, as well as with noninvasive techniques using miniature oxygen electrodes, e.g. in livers perfused in either direction. Differences of opinion in the interpretation of studies with invasive and noninvasive techniques by the authors are discussed. The declining gradient in oxygen concentrations, the decreasing glucagon/insulin ratio and the different innervation could be important factors in the zonal expression of the genes of carbohydrate-metabolizing enzymes. While it is clear that

  2. Live cell imaging of cytosolic NADH/NAD+ ratio in hepatocytes and liver slices.

    Science.gov (United States)

    Masia, Ricard; McCarty, William J; Lahmann, Carolina; Luther, Jay; Chung, Raymond T; Yarmush, Martin L; Yellen, Gary

    2018-01-01

    Fatty liver disease (FLD), the most common chronic liver disease in the United States, may be caused by alcohol or the metabolic syndrome. Alcohol is oxidized in the cytosol of hepatocytes by alcohol dehydrogenase (ADH), which generates NADH and increases cytosolic NADH/NAD + ratio. The increased ratio may be important for development of FLD, but our ability to examine this question is hindered by methodological limitations. To address this, we used the genetically encoded fluorescent sensor Peredox to obtain dynamic, real-time measurements of cytosolic NADH/NAD + ratio in living hepatocytes. Peredox was expressed in dissociated rat hepatocytes and HepG2 cells by transfection, and in mouse liver slices by tail-vein injection of adeno-associated virus (AAV)-encoded sensor. Under control conditions, hepatocytes and liver slices exhibit a relatively low (oxidized) cytosolic NADH/NAD + ratio as reported by Peredox. The ratio responds rapidly and reversibly to substrates of lactate dehydrogenase (LDH) and sorbitol dehydrogenase (SDH). Ethanol causes a robust dose-dependent increase in cytosolic NADH/NAD + ratio, and this increase is mitigated by the presence of NAD + -generating substrates of LDH or SDH. In contrast to hepatocytes and slices, HepG2 cells exhibit a relatively high (reduced) ratio and show minimal responses to substrates of ADH and SDH. In slices, we show that comparable results are obtained with epifluorescence imaging and two-photon fluorescence lifetime imaging (2p-FLIM). Live cell imaging with Peredox is a promising new approach to investigate cytosolic NADH/NAD + ratio in hepatocytes. Imaging in liver slices is particularly attractive because it allows preservation of liver microanatomy and metabolic zonation of hepatocytes. NEW & NOTEWORTHY We describe and validate a new approach for measuring free cytosolic NADH/NAD + ratio in hepatocytes and liver slices: live cell imaging with the fluorescent biosensor Peredox. This approach yields dynamic, real

  3. IL-6 modulates hepatocyte proliferation via induction of HGF/p21cip1: Regulation by SOCS3

    International Nuclear Information System (INIS)

    Sun Rui; Jaruga, Barbara; Kulkarni, Shailin; Sun Haoyu; Gao Bin

    2005-01-01

    The precise role of IL-6 in liver regeneration and hepatocyte proliferation is controversial and the role of SOCS3 in liver regeneration remains unknown. Here we show that in vitro treatment with IL-6 inhibited primary mouse hepatocyte proliferation. IL-6 induced p21 cip1 protein expression in primary mouse hepatocytes. Disruption of the p21 cip1 gene abolished the inhibitory effect of IL-6 on cell proliferation. Co-culture with nonparenchymal liver cells diminished IL-6 inhibition of hepatocyte proliferation, which was likely due to IL-6 stimulation of nonparenchymal cells to produce HGF. Finally, IL-6 induced higher levels of p21 cip1 protein expression and a slightly stronger inhibition of cell proliferation in SOCS3 +/- mouse hepatocytes compared to wild-type hepatocytes, while liver regeneration was enhanced and prolonged in SOCS3 +/- mice. Our findings suggest that IL-6 directly inhibits hepatocyte proliferation via a p21 cip1 -dependent mechanism and indirectly enhances hepatocyte proliferation via stimulating nonparenchymal cells to produce HGF. SOCS3 negatively regulates liver regeneration

  4. 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.

  5. Assessment of mitochondrial dysfunction-related, drug-induced hepatotoxicity in primary rat hepatocytes

    International Nuclear Information System (INIS)

    Liu, Cong; Sekine, Shuichi; Ito, Kousei

    2016-01-01

    Evidence that mitochondrial dysfunction plays a central role in drug-induced liver injury is rapidly accumulating. In contrast to physiological conditions, in which almost all adenosine triphosphate (ATP) in hepatocytes is generated in mitochondria via aerobic respiration, the high glucose content and limited oxygen supply of conventional culture systems force primary hepatocytes to generate most ATP via cytosolic glycolysis. Thus, such anaerobically poised cells are resistant to xenobiotics that impair mitochondrial function, and are not suitable to identify drugs with mitochondrial liabilities. In this study, primary rat hepatocytes were cultured in galactose-based medium, instead of the conventional glucose-based medium, and in hyperoxia to improve the reliance of energy generation on aerobic respiration. Activation of mitochondria was verified by diminished cellular lactate release and increased oxygen consumption. These conditions improved sensitivity to the mitochondrial complex I inhibitor rotenone. Since oxidative stress is also a general cause of mitochondrial impairment, cells were exposed to test compounds in the presence of transferrin to increase the generation of reactive oxygen species via increased uptake of iron. Finally, 14 compounds with reported mitochondrial liabilities were tested to validate this new drug-induced mitochondrial toxicity assay. Overall, the culture of primary rat hepatocytes in galactose, hyperoxia and transferrin is a useful model for the identification of mitochondrial dysfunction-related drug-induced hepatotoxicity. - Highlights: • Drug-induced mitochondrial toxicity was evaluated using primary rat hepatocytes. • Galactose and hyperoxia could activate OXPHOS in primary rat hepatocytes. • Cells with enhanced OXPHOS exhibit improved sensitivity to mitochondrial toxins. • Transferrin potentiate mitochondrial toxicity via increased ROS production.

  6. Assessment of mitochondrial dysfunction-related, drug-induced hepatotoxicity in primary rat hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Cong; Sekine, Shuichi, E-mail: ssekine@faculty.chiba-u.jp; Ito, Kousei

    2016-07-01

    Evidence that mitochondrial dysfunction plays a central role in drug-induced liver injury is rapidly accumulating. In contrast to physiological conditions, in which almost all adenosine triphosphate (ATP) in hepatocytes is generated in mitochondria via aerobic respiration, the high glucose content and limited oxygen supply of conventional culture systems force primary hepatocytes to generate most ATP via cytosolic glycolysis. Thus, such anaerobically poised cells are resistant to xenobiotics that impair mitochondrial function, and are not suitable to identify drugs with mitochondrial liabilities. In this study, primary rat hepatocytes were cultured in galactose-based medium, instead of the conventional glucose-based medium, and in hyperoxia to improve the reliance of energy generation on aerobic respiration. Activation of mitochondria was verified by diminished cellular lactate release and increased oxygen consumption. These conditions improved sensitivity to the mitochondrial complex I inhibitor rotenone. Since oxidative stress is also a general cause of mitochondrial impairment, cells were exposed to test compounds in the presence of transferrin to increase the generation of reactive oxygen species via increased uptake of iron. Finally, 14 compounds with reported mitochondrial liabilities were tested to validate this new drug-induced mitochondrial toxicity assay. Overall, the culture of primary rat hepatocytes in galactose, hyperoxia and transferrin is a useful model for the identification of mitochondrial dysfunction-related drug-induced hepatotoxicity. - Highlights: • Drug-induced mitochondrial toxicity was evaluated using primary rat hepatocytes. • Galactose and hyperoxia could activate OXPHOS in primary rat hepatocytes. • Cells with enhanced OXPHOS exhibit improved sensitivity to mitochondrial toxins. • Transferrin potentiate mitochondrial toxicity via increased ROS production.

  7. Possibility of Undifferentiated Human Thigh Adipose Stem Cells Differentiating into Functional Hepatocytes

    Directory of Open Access Journals (Sweden)

    Jong Hoon Lee

    2012-11-01

    Full Text Available BackgroundThis study aimed to investigate the possibility of isolating mesenchymal stem cells (MSCs from human thigh adipose tissue and the ability of human thigh adipose stem cells (HTASCs to differentiate into hepatocytes.MethodsThe adipose-derived stem cells (ADSCs were isolated from thigh adipose tissue. Growth factors, cytokines, and hormones were added to the collagen coated dishes to induce the undifferentiated HTASCs to differentiate into hepatocyte-like cells. To confirm the experimental results, the expression of hepatocyte-specific markers on undifferentiated and differentiated HTASCs was analyzed using reverse transcription polymerase chain reaction and immunocytochemical staining. Differentiation efficiency was evaluated using functional tests such as periodic acid schiff (PAS staining and detection of the albumin secretion level using enzyme-linked immunosorbent assay (ELISA.ResultsThe majority of the undifferentiated HTASCs were changed into a more polygonal shape showing tight interactions between the cells. The differentiated HTASCs up-regulated mRNA of hepatocyte markers. Immunocytochemical analysis showed that they were intensely stained with anti-albumin antibody compared with undifferentiated HTASCs. PAS staining showed that HTASCs submitted to the hepatocyte differentiation protocol were able to more specifically store glycogen than undifferentiated HTASCs, displaying a purple color in the cytoplasm of the differentiated HTASCs. ELISA analyses showed that differentiated HTASCs could secrete albumin, which is one of the hepatocyte markers.ConclusionsMSCs were islolated from human thigh adipose tissue differentiate to heapatocytes. The source of ADSCs is not only abundant abdominal adipose tissue, but also thigh adipose tissue for cell therapy in liver regeneration and tissue regeneration.

  8. 3D hepatic cultures simultaneously maintain primary hepatocyte and liver sinusoidal endothelial cell phenotypes.

    Directory of Open Access Journals (Sweden)

    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

  9. Pretreatment with mixed-function oxidase inducers increases the sensitivity of the hepatocyte/DNA repair assay

    International Nuclear Information System (INIS)

    Shaddock, J.G.; Heflich, R.H.; McMillan, D.C.; Hinson, J.A.; Casciano, D.A.

    1989-01-01

    A recent National Toxicology Program evaluation indicates that the rat hepatocyte/DNA repair assay has a high false-negative rate and that it is insensitive to some genotoxic hepatocarcinogens as well as other species and organ-specific carcinogens. In this study, the authors examined whether the sensitivity of the hepatocyte/DNA repair assay might be increased through animal pretreatment with various hepatic mixed-function oxidase inducers, i.e., Aroclor 1254, phenobarbital, and 3,3',4,4'-tetrachloroazobenzene (TCAB). The effects on unscheduled DNA synthesis (UDS), a measured of DNA damage and repair, were studied in cultures exposed to known and/or potential carcinogens that had been evaluated as negative or questionable or that produced conflicting results with hepatocytes isolated from uninduced animals. 4,4'-Oxydianiline, 1-nitropy-rene, and TCAB produced concentration-dependent increases in UDS in hepatocytes from rats pretreated with Aroclor 1254. 4,4'-Oxydianiline and TCAB also induced a dose-dependent increase in DNA repair in hepatocytes from rats pretreated with phenobarbital, whereas 1-nitropyrene was negative. These data indicate that the limited sensitivity to chemical carcinogens displayed by the hepatocyte/DNA repair assay may be increased by using hepatocytes isolated from animals exposed to hepatic mixed-function oxidase inducers

  10. Pretreatment with mixed-function oxidase inducers increases the sensitivity of the hepatocyte/DNA repair assay

    Energy Technology Data Exchange (ETDEWEB)

    Shaddock, J.G.; Heflich, R.H.; McMillan, D.C.; Hinson, J.A.; Casciano, D.A. (National Center for Toxicological Research, Jefferson, AK (USA) Univ. of Arkansas for Medical Sciences, Little Rock (USA))

    1989-01-01

    A recent National Toxicology Program evaluation indicates that the rat hepatocyte/DNA repair assay has a high false-negative rate and that it is insensitive to some genotoxic hepatocarcinogens as well as other species and organ-specific carcinogens. In this study, the authors examined whether the sensitivity of the hepatocyte/DNA repair assay might be increased through animal pretreatment with various hepatic mixed-function oxidase inducers, i.e., Aroclor 1254, phenobarbital, and 3,3{prime},4,4{prime}-tetrachloroazobenzene (TCAB). The effects on unscheduled DNA synthesis (UDS), a measured of DNA damage and repair, were studied in cultures exposed to known and/or potential carcinogens that had been evaluated as negative or questionable or that produced conflicting results with hepatocytes isolated from uninduced animals. 4,4{prime}-Oxydianiline, 1-nitropy-rene, and TCAB produced concentration-dependent increases in UDS in hepatocytes from rats pretreated with Aroclor 1254. 4,4{prime}-Oxydianiline and TCAB also induced a dose-dependent increase in DNA repair in hepatocytes from rats pretreated with phenobarbital, whereas 1-nitropyrene was negative. These data indicate that the limited sensitivity to chemical carcinogens displayed by the hepatocyte/DNA repair assay may be increased by using hepatocytes isolated from animals exposed to hepatic mixed-function oxidase inducers.

  11. Metabolism of methyl-branched iodo palmitic acids in cultured hepatocytes

    International Nuclear Information System (INIS)

    Thomas, G.; Pepin, D.; Loriette, C.; Chambaz, J.; Bereziat, G.; Vidal, M.; Apparu, M.; Coornaert, S.

    1989-01-01

    The metabolic fate of methyl-branched iodo fatty acids was studied in primary culture of rat hepatocytes. We compared 16-iodo-2-R,S-methyl palmitic acid (2-Me), which can be β oxidized, with 16-iodo-3-R,S-methyl palmitic acid (3-Me) which can be β oxidized only after an initial α oxydation and with 16-iodo-2,2-dimethyl palmitic acid (2,2-Me 2 ) and 16-iodo-3,3-dimethyl palmitic acid (3,3-Me 2 ) which cannot be β oxidized at all. The normal fate of natural fatty acids was given by comparative experiments with [1- 14 C] palmitic acid. Monomethyl-branched iodo fatty acids were taken up in the same range as palmitic acid but more than dimethyl-branched iodo fatty acids. After a 15-h incubation, acido-soluble products (ASP) accounted for 75% of the radioactivity taken up as 16-iodo-2-methyl palmitic acid, 50% as other methyl-branched iodo fatty acids and only 30% as palmitic acid. Cultured hepatocytes, labelled for 3 h with the various fatty acids and reincubated for 12 h without fatty acid, secreted large amounts of free dimethyl-branched iodo fatty acids as compared to the monomethyl ones and palmitic acid. Only hepatocytes prelabelled with 16-[ 125 I]iodo-2,2-dimethyl palmitic acid exhibited an appreciable secretion of labeled triglycerides, but at a lower rate than with [1- 14 C] palmitic acid. Conversely, the 16-iodo-monomethyl palmitic acids remained chiefly in hepatocyte triglycerides. Minute amounts of 16-iodo-methyl-branched palmitic acids were found in hepatocyte or secreted phospholipids as compared with palmitic acid. (orig.)

  12. 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.

  13. Insulin-induced CARM1 upregulation facilitates hepatocyte proliferation

    International Nuclear Information System (INIS)

    Yeom, Chul-gon; Kim, Dong-il; Park, Min-jung; Choi, Joo-hee; Jeong, Jieun; Wi, Anjin; Park, Whoashig; Han, Ho-jae; Park, Soo-hyun

    2015-01-01

    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

  14. 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. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Optimization of the isolation and cultivation of Cyprinus carpio primary hepatocytes.

    Science.gov (United States)

    Yanhong, Fan; Chenghua, He; Guofang, Liu; Haibin, Zhang

    2008-10-01

    The aquatic environment is affected by numerous chemical contaminants. There is an increasing need to identify these chemicals and to evaluate their potential toxicity towards aquatic life. In this research we optimized techniques for primary cell culture of Cyprinus carpio hepatocytes as one adjunct model for ecotoxicological evaluation of the potential hazards of xenobiotics in the aquatic environment. In this study, Cyprinus carpio hepatocytes were isolated by mechanical separation, two-step collagenase perfusion, and pancreatin digestion. The hepatocytes or parenchymal cells could be separated from cell debris and from non-parenchymal cells by low-speed centrifugation (Percoll gradient centrifugation). The harvested hepatocytes were suspended in DMEM, M199 (cultured in 5% CO(2)), or L-15 (cultured without 5% CO(2)) medium then cultured at 17, 27, or 37 degrees C. Cell yield was counted by use of a hemocytometer, and the viability of the cells was assessed by use of the Trypan blue exclusion test. Results from these studies showed that the best method of isolation was pancreatin digestion (the cell yield was 2.7 x 10(8) per g (liver weight) and the viability was 98.4%) and the best medium was M199 (cultured in 5% CO(2)) or L-15 (cultured without 5% CO(2)). The optimum culture temperature was 27 degrees C. The primary hepatocytes culture of Cyprimus carpio grew well and satisfied requirements for most toxicological experiments in this condition.

  16. Inducibility of carbamoylphosphate synthetase (ammonia) in cultures of embryonic hepatocytes: ontogenesis of the responsiveness to hormones

    NARCIS (Netherlands)

    Lamers, W. H.; Zonneveld, D.; Charles, R.

    1984-01-01

    Glucocorticosteroids and cyclic AMP induce carbamoylphosphate synthetase (ammonia) (CPS) in rat hepatocytes. Using an enzyme immunoassay applied to hepatocyte cultures fixed in situ, it has been demonstrated that the capacity of hepatocytes to synthesize CPS in the presence of both hormones is

  17. Mechanism of free radical generation in platelets and primary hepatocytes: A novel electron spin resonance study.

    Science.gov (United States)

    Wang, Chiun-Lang; Yang, Po-Sheng; Tsao, Jeng-Ting; Jayakumar, Thanasekaran; Wang, Meng-Jiy; Sheu, Joen-Rong; Chou, Duen-Suey

    2018-01-01

    Oxygen free radicals have been implicated in the pathogenesis of toxic liver injury and are thought to be involved in cardiac dysfunction in the cirrhotic heart. Therefore, direct evidence for the electron spin resonance (ESR) detection of how D‑galactosamine (GalN), an established experimental hepatotoxic substance, induced free radicals formation in platelets and primary hepatocytes is presented in the present study. ESR results demonstrated that GalN induced hydroxyl radicals (OH•) in a resting human platelet suspension; however, radicals were not produced in a cell free Fenton reaction system. The GalN‑induced OH• formation was significantly inhibited by the cyclooxygenase (COX) inhibitor indomethasin, though it was not affected by the lipoxygenase (LOX) or cytochrome P450 inhibitors, AA861 and 1‑aminobenzotriazole (ABT), in platelets. In addition, the present study demonstrated that baicalein induced semiquinone free radicals in platelets, which were significantly reduced by the COX inhibitor without affecting the formed OH•. In the mouse primary hepatocytes, the formation of arachidonic acid (AA) induced carbon‑centered radicals that were concentration dependently enhanced by GalN. These radicals were inhibited by AA861, though not affected by indomethasin or ABT. In addition, GalN did not induce platelet aggregation prior to or following collagen pretreatment in human platelets. The results of the present study indicated that GalN and baicalein may induce OH• by COX and LOX in human platelets. GalN also potentiated AA induced carbon‑centered radicals in hepatocytes via cytochrome P450. The present study presented the role of free radicals in the pathophysiological association between platelets and hepatocytes.

  18. 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.

  19. High Throughput Micro-Well Generation of Hepatocyte Micro-Aggregates for Tissue Engineering

    NARCIS (Netherlands)

    Gevaert, Elien; Dollé, Laurent; Billiet, Thomas; Dubruel, Peter; van Grunsven, Leo; van Apeldoorn, Aart A.; Cornelissen, Ria

    2014-01-01

    The main challenge in hepatic tissue engineering is the fast dedifferentiation of primary hepatocytes in vitro. One successful approach to maintain hepatocyte phenotype on the longer term is the cultivation of cells as aggregates. This paper demonstrates the use of an agarose micro-well chip for the

  20. Subtoxic Alterations in Hepatocyte-Derived Exosomes: An Early Step in Drug-Induced Liver Injury?

    Science.gov (United States)

    Holman, Natalie S; Mosedale, Merrie; Wolf, Kristina K; LeCluyse, Edward L; Watkins, Paul B

    2016-06-01

    Drug-induced liver injury (DILI) is a significant clinical and economic problem in the United States, yet the mechanisms that underlie DILI remain poorly understood. Recent evidence suggests that signaling molecules released by stressed hepatocytes can trigger immune responses that may be common across DILI mechanisms. Extracellular vesicles released by hepatocytes, principally hepatocyte-derived exosomes (HDEs), may constitute one such signal. To examine HDE alterations as a function of drug-induced stress, this work utilized prototypical hepatotoxicant acetaminophen (APAP) in male Sprague-Dawley (SD) rats, SD rat hepatocytes, and primary human hepatocytes. HDE were isolated using ExoQuick precipitation reagent and analyzed by quantification of the liver-specific RNAs albumin and microRNA-122 (miR-122). In vivo, significant elevations in circulating exosomal albumin mRNA were observed at subtoxic APAP exposures. Significant increases in exosomal albumin mRNA were also observed in primary rat hepatocytes at subtoxic APAP concentrations. In primary human hepatocytes, APAP elicited increases in both exosomal albumin mRNA and exosomal miR-122 without overt cytotoxicity. However, the number of HDE produced in vitro in response to APAP did not increase with exosomal RNA quantity. We conclude that significant drug-induced alterations in the liver-specific RNA content of HDE occur at subtoxic APAP exposures in vivo and in vitro, and that these changes appear to reflect selective packaging rather than changes in exosome number. The current findings demonstrate that translationally relevant HDE alterations occur in the absence of overt hepatocellular toxicity, and support the hypothesis that HDE released by stressed hepatocytes may mediate early immune responses in DILI. © The Author 2016. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  1. Con-forming bodies: the interplay of machines and bodies and the implications of agency in medical imaging.

    Science.gov (United States)

    Wood, Lisa A

    2016-06-01

    Attending to the material discursive constructions of the patient body within cone beam computed tomography (CBCT) imaging in radiotherapy treatments, in this paper I describe how bodies and machines co-create images. Using an analytical framework inspired by Science and Technology Studies and Feminist Technoscience, I describe the interplay between machines and bodies and the implications of materialities and agency. I argue that patients' bodies play a part in producing scans within acceptable limits of machines as set out through organisational arrangements. In doing so I argue that bodies are fabricated into the order of work prescribed and embedded within and around the CBCT system, becoming, not only the subject of resulting images, but part of that image. The scan is not therefore a representation of a passive subject (a body) but co-produced by the work of practitioners and patients who actively control (and contort) and discipline their body according to protocols and instructions and the CBCT system. In this way I suggest they are 'con-forming' the CBCT image. A Virtual Abstract of this paper can be found at: https://youtu.be/qysCcBGuNSM. © 2015 Foundation for the Sociology of Health & Illness.

  2. Hepatocyte polarization is essential for the productive entry of the hepatitis B virus.

    Science.gov (United States)

    Schulze, Andreas; Mills, Kerry; Weiss, Thomas S; Urban, Stephan

    2012-02-01

    Human hepatitis B virus (HBV) is characterized by a high species specificity and a distinct liver tropism. Within the liver, HBV replication occurs in differentiated and polarized hepatocytes. Accordingly, the in vitro HBV infection of primary human hepatocytes (PHHs) and the human hepatoma cell line, HepaRG, is restricted to differentiated, hepatocyte-like cells. Though preparations of PHH contain up to 100% hepatic cells, cultures of differentiated HepaRG cells are a mixture of hepatocyte-like and biliary-like epithelial cells. We used PHH and HepaRG cells and compared the influence of virus inoculation dose, cell differentiation, and polarization on productive HBV infection. At multiplicities of genome equivalents (mge) >8,000, almost 100% of PHHs could be infected. In contrast, only a subset of HepaRG cells stained positive for HBcAg at comparable or even higher mge. Infection predominantly occurred at the edges of islands of hepatocyte-like HepaRG cells. This indicates a limited accessibility of the HBV receptor, possibly as a result of its polar sorting. Multidrug resistance protein 2 (MRP2), a marker selectively transported to the apical (i.e., canalicular) cell membrane, revealed two polarization phenotypes of HepaRG cells. HBV infection within the islands of hepatocyte-like HepaRG cells preferentially occurred in cells that resemble PHH, exhibiting canalicular structures. However, disruption of cell-cell junctions allowed the additional infection of cells that do not display a PHH-like polarization. HBV enters hepatocytes via the basolateral membrane. This model, at least partially, explains the difference of PHH and HepaRG cells in infection efficacy, provides insights into natural HBV infection, and establishes a basis for optimization of the HepaRG infection system. Copyright © 2011 American Association for the Study of Liver Diseases.

  3. [The polyploidization characteristics of the hepatocytes of the mouse-like hamster Calomyscus mystax].

    Science.gov (United States)

    Anatskaia, O V; Malikov, V G; Meĭer, M N; Kudriavtsev, B N

    1995-01-01

    A cytophotometric measurement of DNA content in hepatocytes of maturing mouse-like hamsters was made. Cells belonging to ordinary mammalian ploidy classes 2c, 2c x 2, 4c, and 4c x 2 made about 90% of the hepatocyte population. The share of binucleated cells wa high (about 80%), the majority of these cells being 2c X 2 hepatocytes. Binucleated cells with tetraploid and diploid nuclei occur in almost every animal. An average hepatocyte ploidy level in mouse-like hamster is 4.6c. The main peculiarity of parenchymal liver cell populations is that up 5% of hepatocytes contain 3--11 nuclei of different ploidy classes. Multinucleated cells increase in number from 1.5% to 4% within the period from one year (the age of maturation) to two years. Later on their percentage does not change. It is found that in binucleated and multinucleated hepatocytes DNA synthesis can proceed asynchronously. Asynchrony in DNA synthesis elevates as the number of nuclei increases. Among the 2c x 2 and 2c x 3 cells an uneven distribution of 3H-thymidine label can occur, respectively, in 5 and in 50% cases, whereas all the cells with more than 3 nuclei display an uneven an uneven 3H-thymidin label distribution. The formation of multinucleated cells is supposed to be associated with asynchrony in DNA-synthesis in binucleated cells and with the restitution of mitosis.

  4. Dendritic cells and hepatocytes use distinct pathways to process protective antigen from plasmodium in vivo.

    Directory of Open Access Journals (Sweden)

    Ian A Cockburn

    2011-03-01

    Full Text Available Malaria-protective CD8+ T cells specific for the circumsporozoite (CS protein are primed by dendritic cells (DCs after sporozoite injection by infected mosquitoes. The primed cells then eliminate parasite liver stages after recognizing the CS epitopes presented by hepatocytes. To define the in vivo processing of CS by DCs and hepatocytes, we generated parasites carrying a mutant CS protein containing the H-2K(b epitope SIINFEKL, and evaluated the T cell response using transgenic and mutant mice. We determined that in both DCs and hepatocytes CS epitopes must reach the cytosol and use the TAP transporters to access the ER. Furthermore, we used endosomal mutant (3d and cytochrome c treated mice to address the role of cross-presentation in the priming and effector phases of the T cell response. We determined that in DCs, CS is cross-presented via endosomes while, conversely, in hepatocytes protein must be secreted directly into the cytosol. This suggests that the main targets of protective CD8+ T cells are parasite proteins exported to the hepatocyte cytosol. Surprisingly, however, secretion of the CS protein into hepatocytes was not dependent upon parasite-export (Pexel/VTS motifs in this protein. Together, these results indicate that the presentation of epitopes to CD8+ T cells follows distinct pathways in DCs when the immune response is induced and in hepatocytes during the effector phase.

  5. Cell therapy from bench to bedside: Hepatocytes from fibroblasts - the truth and myth of transdifferentiation.

    Science.gov (United States)

    Sanal, Madhusudana Girija

    2015-06-07

    Hepatocyte transplantation is an alternative to liver transplantation in certain disorders such as inherited liver diseases and liver failure. It is a relatively less complicated surgical procedure, and has the advantage that it can be repeated several times if unsuccessful. Another advantage is that hepatocytes can be isolated from partly damaged livers which are not suitable for liver transplantation. Despite these advantages hepatocyte transplantation is less popular. Important issues are poor engraftment of the transplanted cells and the scarcity of donor hepatocytes. Generation of "hepatocyte like cells"/iHeps from embryonic stem cells (ES) and induced pluripotent stem cells (iPSCs) by directed differentiation is an emerging solution to the latter issue. Direct conversation or trans-differentiation of fibroblasts to "hepatocyte like cells" is another way which is, being explored. However this method has several inherent and technical disadvantages compared to the directed differentiation from ES or iPSC. There are several methods claiming to be "highly efficient" for generating "highly functional" "hepatocyte like cells". Currently different groups are working independently and coming up with differentiation protocols and each group claiming an advantage for their protocol. Directed differentiation protocols need to be designed, compared, analyzed and tweaked systematically and logically than empirically. There is a need for a well-coordinated global initiative comparable to the Human Genome Project to achieve this goal in the near future.

  6. Chronic alcohol feeding potentiates hormone-induced calcium signalling in hepatocytes.

    Science.gov (United States)

    Bartlett, Paula J; Antony, Anil Noronha; Agarwal, Amit; Hilly, Mauricette; Prince, Victoria L; Combettes, Laurent; Hoek, Jan B; Gaspers, Lawrence D

    2017-05-15

    Chronic alcohol consumption causes a spectrum of liver diseases, but the pathogenic mechanisms driving the onset and progression of disease are not clearly defined. We show that chronic alcohol feeding sensitizes rat hepatocytes to Ca 2+ -mobilizing hormones resulting in a leftward shift in the concentration-response relationship and the transition from oscillatory to more sustained and prolonged Ca 2+ increases. Our data demonstrate that alcohol-dependent adaptation in the Ca 2+ signalling pathway occurs at the level of hormone-induced inositol 1,4,5 trisphosphate (IP 3 ) production and does not involve changes in the sensitivity of the IP 3 receptor or size of internal Ca 2+ stores. We suggest that prolonged and aberrant hormone-evoked Ca 2+ increases may stimulate the production of mitochondrial reactive oxygen species and contribute to alcohol-induced hepatocyte injury. ABSTRACT: 'Adaptive' responses of the liver to chronic alcohol consumption may underlie the development of cell and tissue injury. Alcohol administration can perturb multiple signalling pathways including phosphoinositide-dependent cytosolic calcium ([Ca 2+ ] i ) increases, which can adversely affect mitochondrial Ca 2+ levels, reactive oxygen species production and energy metabolism. Our data indicate that chronic alcohol feeding induces a leftward shift in the dose-response for Ca 2+ -mobilizing hormones resulting in more sustained and prolonged [Ca 2+ ] i increases in both cultured hepatocytes and hepatocytes within the intact perfused liver. Ca 2+ increases were initiated at lower hormone concentrations, and intercellular calcium wave propagation rates were faster in alcoholics compared to controls. Acute alcohol treatment (25 mm) completely inhibited hormone-induced calcium increases in control livers, but not after chronic alcohol-feeding, suggesting desensitization to the inhibitory actions of ethanol. Hormone-induced inositol 1,4,5 trisphosphate (IP 3 ) accumulation and phospholipase C

  7. Comparison of trout hepatocytes and liver S9 fractions as in ...

    Science.gov (United States)

    Isolated hepatocytes and liver S9 fractions have been used to collect in vitro biotransformation data for fish as a means of improving modeled estimates of chemical bioaccumulation. To date, however, there have been few direct comparisons of these two methods. In the present study, cryopreserved trout hepatocytes were used to measure in vitro intrinsic clearance rates for 6 polycyclic aromatic hydrocarbons (PAHs). These rates were extrapolated to estimates of in vivo intrinsic clearance and used as inputs to a well-stirred liver model to predict hepatic clearance. Predicted rates of hepatic clearance were then evaluated by comparison to measured rates determined previously using isolated perfused livers. Hepatic clearance rates predicted using hepatocytes were in good agreement with measured values (fractions. For one compound (benzo[a]pyrene), the in vivo intrinsic clearance rate calculated using S9 data was 10-fold higher than that determined using hepatocytes, possibly due to a diffusion limitation on cellular uptake. Generally, however, there was good agreement between calculated in vivo intrinsic clearance rates obtained using either in vitro test system. These results suggest that both systems can be used to improve

  8. Augmenter of liver regeneration (ALR) protects human hepatocytes against apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Ilowski, Maren [Liver Regeneration Group, Department of Surgery, Grosshadern Hospital, Ludwig Maximilians University, Munich (Germany); Kleespies, Axel [Department of Surgery, Grosshadern Hospital, Ludwig Maximilians University, Munich (Germany); Toni, Enrico N. de [Department of Medicine II, Grosshadern Hospital, Ludwig Maximilians University, Munich (Germany); Donabauer, Barbara [Liver Regeneration Group, Department of Surgery, Grosshadern Hospital, Ludwig Maximilians University, Munich (Germany); Jauch, Karl-Walter [Department of Surgery, Grosshadern Hospital, Ludwig Maximilians University, Munich (Germany); Hengstler, Jan G. [Leibniz Research Centre for Working Environment and Human Factors, Technical University, Dortmund (Germany); Thasler, Wolfgang E., E-mail: wolfgang.thasler@med.uni-muenchen.de [Liver Regeneration Group, Department of Surgery, Grosshadern Hospital, Ludwig Maximilians University, Munich (Germany); Department of Surgery, Grosshadern Hospital, Ludwig Maximilians University, Munich (Germany)

    2011-01-07

    Research highlights: {yields} ALR decreases cytochrome c release from mitochondria. {yields} ALR protects hepatocytes against apoptosis induction by ethanol, TRAIL, anti-Apo, TGF-{beta} and actinomycin D. {yields} ALR exerts a liver-specific anti-apoptotic effect. {yields} A possible medical usage of ALR regarding protection of liver cells during apoptosis inducing therapies. -- Abstract: Augmenter of liver regeneration (ALR) is known to support liver regeneration and to stimulate proliferation of hepatocytes. However, it is not known if ALR exerts anti-apoptotic effects in human hepatocytes and whether this protective effect is cell type specific. This is relevant, because compounds that protect the liver against apoptosis without undesired effects, such as protection of metastatic tumour cells, would be appreciated in several clinical settings. Primary human hepatocytes (phH) and organotypic cancer cell lines were exposed to different concentrations of apoptosis inducers (ethanol, TRAIL, anti-Apo, TGF-{beta}, actinomycin D) and cultured with or without recombinant human ALR (rhALR). Apoptosis was evaluated by the release of cytochrome c from mitochondria and by FACS with propidium iodide (PI) staining. ALR significantly decreased apoptosis induced by ethanol, TRAIL, anti-Apo, TGF-{beta} and actinomycin D. Further, the anti-apoptotic effect of ALR was observed in primary human hepatocytes and in HepG2 cells but not in bronchial (BC1), colonic (SW480), gastric (GC1) and pancreatic (L3.6PL) cell lines. Therefore, the hepatotrophic growth factor ALR acts in a liver specific manner with regards to both its mitogenic and its anti-apoptotic effect. Unlike the growth factors HGF and EGF, rhALR acts in a liver specific manner. Therefore, ALR is a promising candidate for further evaluation as a possible hepatoprotective factor in clinical settings.

  9. Augmenter of liver regeneration (ALR) protects human hepatocytes against apoptosis

    International Nuclear Information System (INIS)

    Ilowski, Maren; Kleespies, Axel; Toni, Enrico N. de; Donabauer, Barbara; Jauch, Karl-Walter; Hengstler, Jan G.; Thasler, Wolfgang E.

    2011-01-01

    Research highlights: → ALR decreases cytochrome c release from mitochondria. → ALR protects hepatocytes against apoptosis induction by ethanol, TRAIL, anti-Apo, TGF-β and actinomycin D. → ALR exerts a liver-specific anti-apoptotic effect. → A possible medical usage of ALR regarding protection of liver cells during apoptosis inducing therapies. -- Abstract: Augmenter of liver regeneration (ALR) is known to support liver regeneration and to stimulate proliferation of hepatocytes. However, it is not known if ALR exerts anti-apoptotic effects in human hepatocytes and whether this protective effect is cell type specific. This is relevant, because compounds that protect the liver against apoptosis without undesired effects, such as protection of metastatic tumour cells, would be appreciated in several clinical settings. Primary human hepatocytes (phH) and organotypic cancer cell lines were exposed to different concentrations of apoptosis inducers (ethanol, TRAIL, anti-Apo, TGF-β, actinomycin D) and cultured with or without recombinant human ALR (rhALR). Apoptosis was evaluated by the release of cytochrome c from mitochondria and by FACS with propidium iodide (PI) staining. ALR significantly decreased apoptosis induced by ethanol, TRAIL, anti-Apo, TGF-β and actinomycin D. Further, the anti-apoptotic effect of ALR was observed in primary human hepatocytes and in HepG2 cells but not in bronchial (BC1), colonic (SW480), gastric (GC1) and pancreatic (L3.6PL) cell lines. Therefore, the hepatotrophic growth factor ALR acts in a liver specific manner with regards to both its mitogenic and its anti-apoptotic effect. Unlike the growth factors HGF and EGF, rhALR acts in a liver specific manner. Therefore, ALR is a promising candidate for further evaluation as a possible hepatoprotective factor in clinical settings.

  10. UDP-glucuronosyltransferase-dependent bioactivation of clofibric acid to a DNA-damaging intermediate in mouse hepatocytes.

    Science.gov (United States)

    Ghaoui, Roula; Sallustio, Benedetta C; Burcham, Philip C; Fontaine, Frank R

    2003-05-06

    Glucuronidation of a number of carboxyl-containing drugs generates reactive acyl glucuronide metabolites. These electrophilic species alkylate cell proteins and may be implicated in the pathogenesis of a number of toxic syndromes seen in patients receiving the parent aglycones. Whether acyl glucuronides also attack nuclear DNA is unknown, although the acyl glucuronide formed from clofibric acid was recently found to decrease the transfection efficiency of phage DNA and generate strand breaks in plasmid DNA in vitro. To determine if such a DNA damage occurs within a cellular environment, the comet assay (i.e. single-cell gel electrophoresis) was used to detect DNA lesions in the nuclear genome of isolated mouse hepatocytes cultured with clofibric acid. Overnight exposure to 50 microM and higher concentrations of clofibric acid produced concentration-dependent increases in the comet areas of hepatocyte nuclei, with 1 mM clofibrate producing a 3.6-fold elevation over controls. These effects closely coincided with culture medium concentrations of the glucuronide metabolite formed from clofibric acid, 1-O-beta-clofibryl glucuronide. Consistent with a role for glucuronidation in the DNA damage observed, the glucuronidation inhibitor borneol diminished glucuronide formation from 100 microM clofibrate by 98% and returned comet areas to baseline levels. Collectively, these results suggest that the acyl glucuronide formed from clofibric acid is capable of migrating from its site of formation within the endoplasmic reticulum to generate strand nicks in nuclear DNA.

  11. Hydrodynamic Delivery of Cre Protein to Lineage-Mark or Time-Stamp Mouse Hepatocytes In situ

    Science.gov (United States)

    Sonsteng, Katherine M.; Prigge, Justin R.; Talago, Emily A.; June, Ronald K.; Schmidt, Edward E.

    2014-01-01

    Cre-responsive fluorescent marker alleles are powerful tools for cell lineage tracing in mice; however their utility is limited by regulation of Cre activity. When targeting hepatocytes, hydrodynamic delivery of a Cre-expression plasmid can convert Cre-responsive alleles without inducing the intracellular or systemic antiviral responses often associated with viral-derived Cre-expression vectors. In this method, rapid high-volume intravenous inoculation induces hepatocyte-targeted uptake of extracellular molecules. Here we tested whether hydrodynamic delivery of Cre protein or Cre fused to the HIV-TAT cell-penetrating peptide could convert Cre-responsive reporters in hepatocytes of mice. Hydrodynamic delivery of 2 nmol of either Cre or TAT-Cre protein converted the reporter allele in 5 to 20% of hepatocytes. Neither protein gave detectable Cre activity in endothelia, non-liver organs, or non-hepatocyte cells in liver. Using mice homozygous for a Cre-responsive marker that directs red- (Cre-naïve) or green- (Cre-converted) fluorescent proteins to the nucleus, we assessed sub-saturation Cre-activity. One month after hydrodynamic inoculation with Cre protein, 58% of hepatocyte nuclei that were green were also red, indicating that less than half of the hepatocytes that had obtained enough Cre to convert one marker allele to green were able to convert all alleles. For comparison, one month after hydrodynamic delivery of a Cre-expression plasmid with a weak promoter, only 26% of the green nuclei were also red. Our results show that hydrodynamic delivery of Cre protein allows rapid allelic conversion in hepatocytes, but Cre-activity is sub-saturating so many cells will not convert multiple Cre-responsive alleles. PMID:24626158

  12. Intracellular pH regulation in hepatocytes isolated from three teleost species.

    Science.gov (United States)

    Furimsky, M; Moon, T W; Perry, S F

    1999-09-01

    The mechanisms of intracellular pH (pH(i)) regulation were studied in hepatocytes isolated from three species of teleost: rainbow trout (Oncorhynchus mykiss), black bullhead (Ameiurus melas) and American eel (Anguilla rostrata). Intracellular pH was monitored over time using the pH-sensitive fluorescent dye BCECF in response to acid loading under control conditions and in different experimental media containing either low Na(+) or Cl(-) concentrations, the Na(+)-H(+) exchanger blocker amiloride or the blocker of the V-type H(+)-ATPase, bafilomycin A(1). In trout and bullhead hepatocytes, recovery to an intracellular acid load occurred principally by way of a Na(+)-dependent amiloride-sensitive Na(+)-H(+) exchanger. In eel hepatocytes, the Na(+)-H(+) exchanger did not contribute to recovery to an acid load though evidence suggests that it is present on the cell membrane and participates in the maintenance of steady-state pH(i). The V-type H(+)-ATPase did not participate in recovery to an acid load in any species. A Cl(-)-HCO(3)(-) exchanger may play a role in recovery to an acid load in eel hepatocytes by switching off and retaining base that would normally be tonically extruded. Thus, it is clear that hepatocytes isolated from the three species are capable of regulating pH(i), principally by way of a Na(+)-H(+) exchanger and a Cl(-)-HCO(3)(-) exchanger, but do not exploit identical mechanisms for pH(i) recovery. J. Exp. Zool. 284:361-367, 1999. Copyright 1999 Wiley-Liss, Inc.

  13. Induced Mitogenic Activity in AML-12 Mouse Hepatocytes Exposed to Low-dose Ultra-Wideband Electromagnetic Radiation

    Directory of Open Access Journals (Sweden)

    P. B. Tchounwou

    2005-04-01

    Full Text Available Ultra–wideband (UWB technology has increased with the use of various civilian and military applications. In the present study, we hypothesized that low-dose UWB electromagnetic radiation (UWBR could elicit a mitogenic effect in AML-12 mouse hepatocytes, in vitro. To test this hypothesis, we exposed AML-12 mouse hepatocytes, to UWBR in a specially constructed gigahertz transverse electromagnetic mode (GTEM cell. Cells were exposed to UWBR for 2 h at a temperature of 23°C, a pulse width of 10 ns, a repetition rate of 1 kHz, and field strength of 5-20 kV/m. UWB pulses were triggered by an external pulse generator for UWBR exposure but were not triggered for the sham exposure. We performed an MTT Assay to assess cell viability for UWBR-treated and sham-exposed hepatocytes. Data from viability studies indicated a time-related increase in hepatocytes at time intervals from 8-24 h post exposure. UWBR exerted a statistically significant (p < 0.05 dose-dependent response in cell viability in both serum-treated and serum free medium (SFM -treated hepatocytes. Western blot analysis of hepatocyte lysates demonstrated that cyclin A protein was induced in hepatocytes, suggesting that increased MTT activity after UWBR exposure was due to cell proliferation. This study indicates that UWBR has a mitogenic effect on AML-12 mouse hepatocytes and implicates a possible role for UWBR in hepatocarcinoma.

  14. Wave-free floating body forms for a shallow sea area; Senkaiiki no naminashi futai keijo ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Kyozuka, Y; Nariai, Y [Kyushu University, Fukuoka (Japan)

    1997-10-01

    In column footing or semi-submergible type marine structures, a vertical wave force vanishes at a specific period of waves. This phenomenon is called wave-free characteristics. This wave-free characteristics make it possible to design marine structures superior in oscillation performance in waves. Since Bessho`s wave-free theory is useful only for an infinite water depth, this paper studied the wave-free theory for a shallow sea area. On a wave-free singularity and required floating body form, 2-D and 3-D axisymmetric floating body forms were determined, and vertical wave force characteristics of the obtained body forms were calculated and verified experimentally. Since the source term of the wave-free singularity was weaker in a shallow sea area than an infinite deep water area, resulting in the narrow width of the obtained wave-free body forms in a shallow sea area. The wave-free theory for a shallow sea area was verified by both numerical calculation based on a singularity distribution method and model experiment for these floating body forms. 3 refs., 10 figs.

  15. Lipopolysaccharide impairs hepatocyte ureagenesis from ammonia: involvement of mitochondrial aquaporin-8.

    Science.gov (United States)

    Soria, Leandro R; Marrone, Julieta; Molinas, Sara M; Lehmann, Guillermo L; Calamita, Giuseppe; Marinelli, Raúl A

    2014-05-02

    We recently reported that hepatocyte mitochondrial aquaporin-8 (mtAQP8) channels facilitate the uptake of ammonia and its metabolism into urea. Here we studied the effect of bacterial lipopolysaccharides (LPS) on ammonia-derived ureagenesis. In LPS-treated rats, hepatic mtAQP8 protein expression and diffusional ammonia permeability (measured utilizing ammonia analogues) of liver inner mitochondrial membranes were downregulated. NMR studies using 15N-labeled ammonia indicated that basal and glucagon-induced ureagenesis from ammonia were significantly reduced in hepatocytes from LPS-treated rats. Our data suggest that hepatocyte mtAQP8-mediated ammonia removal via ureagenesis is impaired by LPS, a mechanism potentially relevant to the molecular pathogenesis of defective hepatic ammonia detoxification in sepsis. Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  16. Regulation of lipid synthesis in hepatocytes from lean and obese Zucker rats

    International Nuclear Information System (INIS)

    Triscari, J.; Greenwood, M.R.; Sullivan, A.C.

    1981-01-01

    Fatty acid synthesis and CO 2 production were evaluated in hepatocytes from lean and obese Zucker rats in the presence of 3 H 2 O, and several carbon precursors. The incorporation of 3 H 2 O into fatty acids was greater in obese compared to lean rats in both the isolated hepatocyte and in vivo. The rates of incorporation of 3 H 2 O into fatty acids and cholesterol in hepatocytes of both lean and obese rats were linear for 2 hr, in the absence or presence of 16.7 mM glucose. Rates of fatty acid synthesis were higher in the presence of 16.7 mM glucose compared to the absence of glucose in both lean and obese while rates of cholesterol synthesis were similar. The incorporation of 3H2O into fatty acids, but not into cholesterol, was correlated with increasing glucose concentration and was 2 to three-fold higher in hepatocytes of obese compared to lean rats in the presence of several carbon precursors. Differences in CO 2 production between lean and obese rats suggested increased pentose phosphate shunt activity, decreased pyruvate dehydrogenase activity, and lower tricarboxylic acid cycle activity in obese rats. Fatty acid synthesis and CO 2 production from 3 H 2 O and [U- 14 C]glucose in hepatocytes of lean and obese rats was similarly elevated by insulin and depressed by glucagon at several concentrations, suggesting that hepatocytes of obese animals respond to these hormones. These data indicate that rates of hepatic fatty acid synthesis although higher in obese rats respond to modulation in a fashion which is similar to the response in lean rats. The present studies suggest that the oxidation of several carbon precursors in the tricarboxylic acid cycle is diminished in obese compared to lean rats, but pentose phosphate shunt activity is greater in the obese Zucker rats

  17. Bile acid-induced necrosis in primary human hepatocytes and in patients with obstructive cholestasis

    Energy Technology Data Exchange (ETDEWEB)

    Woolbright, Benjamin L.; Dorko, Kenneth [Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Antoine, Daniel J.; Clarke, Joanna I. [MRC Centre for Drug Safety Science, Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool (United Kingdom); Gholami, Parviz [Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS (United States); Li, Feng [Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Kumer, Sean C.; Schmitt, Timothy M.; Forster, Jameson [Department of Surgery, University of Kansas Medical Center, Kansas City, KS (United States); Fan, Fang [Department of Pathology, University of Kansas Medical Center, Kansas City, KS (United States); Jenkins, Rosalind E.; Park, B. Kevin [MRC Centre for Drug Safety Science, Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool (United Kingdom); Hagenbuch, Bruno [Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Olyaee, Mojtaba [Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS (United States); Jaeschke, Hartmut, E-mail: hjaeschke@kumc.edu [Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States)

    2015-03-15

    Accumulation of bile acids is a major mediator of cholestatic liver injury. Recent studies indicate bile acid composition between humans and rodents is dramatically different, as humans have a higher percent of glycine conjugated bile acids and increased chenodeoxycholate content, which increases the hydrophobicity index of bile acids. This increase may lead to direct toxicity that kills hepatocytes, and promotes inflammation. To address this issue, this study assessed how pathophysiological concentrations of bile acids measured in cholestatic patients affected primary human hepatocytes. Individual bile acid levels were determined in serum and bile by UPLC/QTOFMS in patients with extrahepatic cholestasis with, or without, concurrent increases in serum transaminases. Bile acid levels increased in serum of patients with liver injury, while biliary levels decreased, implicating infarction of the biliary tracts. To assess bile acid-induced toxicity in man, primary human hepatocytes were treated with relevant concentrations, derived from patient data, of the model bile acid glycochenodeoxycholic acid (GCDC). Treatment with GCDC resulted in necrosis with no increase in apoptotic parameters. This was recapitulated by treatment with biliary bile acid concentrations, but not serum concentrations. Marked elevations in serum full-length cytokeratin-18, high mobility group box 1 protein (HMGB1), and acetylated HMGB1 confirmed inflammatory necrosis in injured patients; only modest elevations in caspase-cleaved cytokeratin-18 were observed. These data suggest human hepatocytes are more resistant to human-relevant bile acids than rodent hepatocytes, and die through necrosis when exposed to bile acids. These mechanisms of cholestasis in humans are fundamentally different to mechanisms observed in rodent models. - Highlights: • Cholestatic liver injury is due to cytoplasmic bile acid accumulation in hepatocytes. • Primary human hepatocytes are resistant to BA-induced injury

  18. Haematological and Histological Alterations Induced in Rats by Gamma Rays and the Therapeutic Action of Phenolic compounds in Nano Particles Form

    International Nuclear Information System (INIS)

    El Masry, S.A.M.; Ragab, E.A.E.; Ali, E.N.; Askar, M.A.; Badawi, A.M.

    2012-01-01

    Phenolic compounds as para-coumaric acids and caffeic acids are natural compounds in nano form as Zinc Coumarate Nano Particles (ZnCoum. NPs) and Zinc Caffeiate Nano Particles (ZnCaf. NPs) have been shown to confer various biological effects, anticancer, enhance immune system and antioxidant properties. The present study was undertaken to evaluate the radio protective and possess ability of ZnCoum.NPs and ZnCaf.NPs against whole body γirradiation with a dose of 3 Gy, 4 times, every week up to 12 Gy. ZnCoum.NPs and ZnCaf. NPs were given to rats by intraperitoneal injection at a concentration of 5 mg/kg and 15 mg/kg body weight respectively, for 7 successive days, post irradiation for (ZnCoum. NPs + ZnCaf. NPs) and [(ZnCoum. NPs + ZnCaf. NPs) + Irradiated] groups and for 30 successive days for (ZnCoum. NPs + ZnCaf. NPs), [(ZnCoum. NPs + ZnCaf. NPs) + Irradiated] and [Irradiated + (ZnCoum. NPs + ZnCaf. NPs)] groups. The results indicated that γ- irradiated group caused a significant decrease of body weight and hematological level disorders. Histological study also revealed that γ-irradiation induced vacuoles degeneration and necrosis of a great number of hepatocytes together with several hemorrhage and interstitial oedema. Whilst, the treatment with ZnCoum. NPs + ZnCaf. NPs pre or post-exposure to γ-ray protected blood cells and hepatocytes from harmful effects of γ-radiation.

  19. Long-term liver-specific functions of hepatocytes in electrospun chitosan nanofiber scaffolds coated with fibronectin.

    Science.gov (United States)

    Rajendran, Divya; Hussain, Ali; Yip, Derek; Parekh, Amit; Shrirao, Anil; Cho, Cheul H

    2017-08-01

    In this study, a new 3D liver model was developed using biomimetic nanofiber scaffolds and co-culture system consisting of hepatocytes and fibroblasts for the maintenance of long-term liver functions. The chitosan nanofiber scaffolds were fabricated by the electrospinning technique. To enhance cellular adhesion and spreading, the surfaces of the chitosan scaffolds were coated with fibronectin (FN) by adsorption and evaluated for various cell types. Cellular phenotype, protein expression, and liver-specific functions were extensively characterized by immunofluorescent and histochemical stainings, albumin enzyme-linked immunosorbent assay and Cytochrome p450 detoxification assays, and scanning electron microscopy. The electrospun chitosan scaffolds exhibited a highly porous and randomly oriented nanofibrous structure. The FN coating on the surface of the chitosan nanofibers significantly enhanced cell attachment and spreading, as expected, as surface modification with this cell adhesion molecule on the chitosan surface is important for focal adhesion formation and integrin binding. Comparison of hepatocyte mono-cultures and co-cultures in 3D culture systems indicated that the hepatocytes in co-cultures formed colonies and maintained their morphologies and functions for prolonged periods of time. The 3D liver tissue model developed in this study will provide useful tools toward the development of engineered liver tissues for drug screening and tissue engineering applications. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2119-2128, 2017. © 2017 Wiley Periodicals, Inc.

  20. The role of hepatocyte nuclear factor 4 alpha in development and progression of liver diseases

    Directory of Open Access Journals (Sweden)

    YANG Jinlian

    2016-02-01

    Full Text Available Hepatocyte nuclear factor 4 alpha (HNF4α, a member of the nuclear receptor superfamily, has a high expression level in mature hepatocytes. HNF4α can regulate hepatocyte-specific gene expression at a transcriptional level, promote hepatocyte development and differentiation, participate in establishment and maintenance of hepatocyte polarity, and enhance the synthetic, metabolic, and detoxifying functions of the liver. Through inhibiting the activation of hepatic stellate cells, reversing epithelial-mesenchymal transition, and inhibiting the proliferation, invasion, and metastasis of hepatoma cells, HNF4α may be involved in the development and progression of various liver diseases including liver fibrosis, liver cirrhosis, and hepatocellular carcinoma. This paper elaborates on the biological functions of HNF4α, and summarizes and analyzes the research advances in the mechanisms of action of HNF4α in the pathological process of liver diseases, in order to provide references for further investigation of the potential targeted therapies for liver diseases.

  1. Optimization of the isolation and cultivation of Cyprinus carpio primary hepatocytes

    Science.gov (United States)

    Yanhong, Fan; Chenghua, He; Guofang, Liu

    2008-01-01

    The aquatic environment is affected by numerous chemical contaminants. There is an increasing need to identify these chemicals and to evaluate their potential toxicity towards aquatic life. In this research we optimized techniques for primary cell culture of Cyprinus carpio hepatocytes as one adjunct model for ecotoxicological evaluation of the potential hazards of xenobiotics in the aquatic environment. In this study, Cyprinus carpio hepatocytes were isolated by mechanical separation, two-step collagenase perfusion, and pancreatin digestion. The hepatocytes or parenchymal cells could be separated from cell debris and from non-parenchymal cells by low-speed centrifugation (Percoll gradient centrifugation). The harvested hepatocytes were suspended in DMEM, M199 (cultured in 5% CO2), or L-15 (cultured without 5% CO2) medium then cultured at 17, 27, or 37 °C. Cell yield was counted by use of a hemocytometer, and the viability of the cells was assessed by use of the Trypan blue exclusion test. Results from these studies showed that the best method of isolation was pancreatin digestion (the cell yield was 2.7 × 108 per g (liver weight) and the viability was 98.4%) and the best medium was M199 (cultured in 5% CO2) or L-15 (cultured without 5% CO2). The optimum culture temperature was 27 °C. The primary hepatocytes culture of Cyprimus carpio grew well and satisfied requirements for most toxicological experiments in this condition. PMID:19002769

  2. Independent, parallel pathways to CXCL10 induction in HCV-infected hepatocytes.

    Science.gov (United States)

    Brownell, Jessica; Wagoner, Jessica; Lovelace, Erica S; Thirstrup, Derek; Mohar, Isaac; Smith, Wesley; Giugliano, Silvia; Li, Kui; Crispe, I Nicholas; Rosen, Hugo R; Polyak, Stephen J

    2013-10-01

    The pro-inflammatory chemokine CXCL10 is induced by HCV infection in vitro and in vivo, and is associated with outcome of IFN (interferon)-based therapy. We studied how hepatocyte sensing of early HCV infection via TLR3 (Toll-like receptor 3) and RIG-I (retinoic acid inducible gene I) led to expression of CXCL10. CXCL10, type I IFN, and type III IFN mRNAs and proteins were measured in PHH (primary human hepatocytes) and hepatocyte lines harboring functional or non-functional TLR3 and RIG-I pathways following HCV infection or exposure to receptor-specific stimuli. HuH7 human hepatoma cells expressing both TLR3 and RIG-I produced maximal CXCL10 during early HCV infection. Neutralization of type I and type III IFNs had no impact on virus-induced CXCL10 expression in TLR3+/RIG-I+ HuH7 cells, but reduced CXCL10 expression in PHH. PHH cultures were positive for monocyte, macrophage, and dendritic cell mRNAs. Immunodepletion of non-parenchymal cells (NPCs) eliminated marker expression in PHH cultures, which then showed no IFN requirement for CXCL10 induction during HCV infection. Immunofluorescence studies also revealed a positive correlation between intracellular HCV Core and CXCL10 protein expression (r(2) = 0.88, p ≤ 0.001). While CXCL10 induction in hepatocytes during the initial phase of HCV infection is independent of hepatocyte-derived type I and type III IFNs, NPC-derived IFNs contribute to CXCL10 induction during HCV infection in PHH cultures. Copyright © 2013 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

  3. Impaired mitochondrial metabolism and protein synthesis in streptozotocin diabetic rat hepatocytes

    International Nuclear Information System (INIS)

    Memon, R.A.; Bessman, S.P.; Mohan, C.

    1990-01-01

    Isolated hepatocytes prepared from control, streptozotocin diabetic rats were incubated at 30 degrees C in Krebs-Henseleit bicarbonate buffer, pH 7.4, containing 0.5 mM concentration of each of the 20 natural amino acids. Effect of insulin on the oxidation of 2,3- 14 C and 1,4- 14 C succinate (suc) carbons and their incorporation into hepatocyte protein, lipid and various metabolic intermediates was studied. Mitochondrial oxidation of suc carbons and their incorporation into protein and lipid was significantly lower in diabetic and insulin treated diabetic rats. Diabetic rats failed to exhibit any significant insulin effect on the oxidation of either 2,3 or 1,4- 14 C suc carbons. Amphibolic channeling of 2,3- 14 C suc carbons into amino acids was significantly reduced in hepatocytes of diabetic rats, however, more of these carbons were diverted into the gluconeogenesis pathway. Diabetes caused a far greater decrease in the oxidation of 2,3- 14 C suc carbons as compared to 1,4- 14 C suc. Based on an earlier report that insulin stimulates only the intramitochondrial Krebs cycle reactions, the authors conclude that the diminished level of anabolic activities in the diabetic rat hepatocytes is due to the subsequent reduction in amphibolic channeling of metabolic intermediates

  4. Preventing hepatocyte oxidative stress cytotoxicity with Mangifera indica L. extract (Vimang).

    Science.gov (United States)

    Remirez, Diadelis; Tafazoli, Shahrzad; Delgado, Rene; Harandi, Asghar A; O'Brien, Peter J

    2005-01-01

    Vimang is an aqueous extract of Mangifera indica used in Cuba to improve the quality of life in patients suffering from inflammatory diseases. In the present study we evaluated the effects of Vimang at preventing reactive oxygen species (ROS) formation and lipid peroxidation in intact isolated rat hepatocytes. Vimang at 20, 50 and 100 microg/ml inhibited hepatocyte ROS formation induced by glucose-glucose oxidase. Hepatocyte cytotoxicity and lipid peroxidation induced by cumene hydroperoxide was also inhibited by Vimang in a dose and time dependent manner at the same concentration. Vimang also inhibited superoxide radical formation by xanthine oxidase and hypoxanthine. The superoxide radical scavenging and antioxidant activity of the Vimang extract was likely related to its gallates, catechins and mangiferin content. To our knowledge, this is the first report of cytoprotective antioxidant effects of Vimang in cellular oxidative stress models.

  5. U.V.-enhanced reactivation of u.v.-irradiated herpes virus by primary cultures of rat hepatocytes

    International Nuclear Information System (INIS)

    Zurlo, J.; Yager, J.D.

    1984-01-01

    Carcinogen treatment of cultured mammalian cells prior to infection with u.v.-irradiated virus results in enhanced virus survival and mutagenesis suggesting the induction of SOS-type processes. In this paper, we report the development of a primary rat hepatocyte culture system to investigate cellular responses to DNA damage which may be relevant to hepatocarcinogenesis in vivo. We have obtained data demonstrating that enhanced reactivation of u.v.-irradiated Herpes simplex virus type 1 (HSV-1) occurs in hepatocytes irradiated with u.v. Cultured hepatocytes were pretreated with u.v. at the time of enhanced DNA synthesis. These treatments caused an inhibition followed by a recovery of DNA synthesis. At various times after pretreatment, the hepatocytes were infected with control or u.v.-irradiated HSV-1 at low multiplicity, and virus survival was measured by direct plaque assay. U.v.-irradiated HSV-1 exhibited the expected two-component survival curve in control or u.v. pretreated hepatocytes. The magnitude of enhanced reactivation of HSV-1 was dependent on the u.v. dose to the hepatocytes, the time of infection following u.v. pretreatment, and the level of DNA synthesis at the time of pretreatment. These results suggest that u.v. treatment of rat hepatocytes causes the induction of SOS-type functions that may have a role in the initiation of hepatocarcinogenesis

  6. Human hepatocyte depletion in the presence of HIV-1 infection in dual reconstituted humanized mice

    Science.gov (United States)

    Wang, Weimin; Cheng, Yan; Makarov, Edward; Ganesan, Murali; Gebhart, Catherine L.; Gorantla, Santhi; Osna, Natalia

    2018-01-01

    ABSTRACT Human immunodeficiency virus type 1 (HIV-1) infection impairs liver function, and liver diseases have become a leading cause of morbidity in infected patients. The immunopathology of liver damage caused by HIV-1 remains unclear. We used chimeric mice dually reconstituted with a human immune system and hepatocytes to address the relevance of the model to pathobiology questions related to human hepatocyte survival in the presence of systemic infection. TK-NOG males were transplanted with mismatched human hematopoietic stem/progenitor cells and hepatocytes, human albumin concentration and the presence of human immune cells in blood were monitored for hepatocytes and immune reconstitution, and mice were infected with HIV-1. HIV-1-infected animals showed a decline in human albumin concentration with a significant reduction in percentage of human hepatocytes compared to uninfected mice. The decrease in human albumin levels correlated with a decline in CD4+ cells in the liver and with an increase in HIV-1 viral load. HIV-1 infection elicited proinflammatory response in the immunological milieu of the liver in HIV-infected mice compared to uninfected animals, as determined by upregulation of IL23, CXCL10 and multiple toll-like receptor expression. The inflammatory reaction associated with HIV-1 infection in vivo could contribute to the depletion and dysfunction of hepatocytes. The dual reconstituted TK-NOG mouse model is a feasible platform to investigate hepatocyte-related HIV-1 immunopathogenesis. This article has an associated First Person interview with the first author of the paper. PMID:29361613

  7. Human hepatocyte depletion in the presence of HIV-1 infection in dual reconstituted humanized mice

    Directory of Open Access Journals (Sweden)

    Raghubendra Singh Dagur

    2018-02-01

    Full Text Available Human immunodeficiency virus type 1 (HIV-1 infection impairs liver function, and liver diseases have become a leading cause of morbidity in infected patients. The immunopathology of liver damage caused by HIV-1 remains unclear. We used chimeric mice dually reconstituted with a human immune system and hepatocytes to address the relevance of the model to pathobiology questions related to human hepatocyte survival in the presence of systemic infection. TK-NOG males were transplanted with mismatched human hematopoietic stem/progenitor cells and hepatocytes, human albumin concentration and the presence of human immune cells in blood were monitored for hepatocytes and immune reconstitution, and mice were infected with HIV-1. HIV-1-infected animals showed a decline in human albumin concentration with a significant reduction in percentage of human hepatocytes compared to uninfected mice. The decrease in human albumin levels correlated with a decline in CD4+ cells in the liver and with an increase in HIV-1 viral load. HIV-1 infection elicited proinflammatory response in the immunological milieu of the liver in HIV-infected mice compared to uninfected animals, as determined by upregulation of IL23, CXCL10 and multiple toll-like receptor expression. The inflammatory reaction associated with HIV-1 infection in vivo could contribute to the depletion and dysfunction of hepatocytes. The dual reconstituted TK-NOG mouse model is a feasible platform to investigate hepatocyte-related HIV-1 immunopathogenesis. This article has an associated First Person interview with the first author of the paper.

  8. [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. Copyright © 2013 AEC. Published by Elsevier Espana. All rights reserved.

  9. Effects of Cytochrome P 450 Inhibitors on Itraconazole and Fluconazole Induced Cytotoxicity in Hepatocytes

    International Nuclear Information System (INIS)

    Somchit, N.; Ngee, C.S.; Yaakob, A.; Ahmad, Z.; Zakaria, Z.A.

    2009-01-01

    Itraconazole and fluconazole have been reported to induce hepatotoxicity in patients. The present study was designed to investigate the role of cytochrome P450 inhibitors, SKF 525A, and curcumin pretreatment on the cytotoxicity of antifungal drugs fluconazole and itraconazole. For 3 consecutive days, female rats were administered daily SKF 525A or curcumin (5 and 25?mg/kg). Control rats received an equivalent amount of dosed vehicle. The animals were anaesthetised 24 hours after receiving the last dose for liver perfusion. Hepatocytes were then exposed to various concentrations of antifungal drugs. In vitro incubation of hepatocytes with itraconazole revealed significantly lower viability when compared to fluconazole as assessed by lactate dehydrogenase, aspartate aminotransferase and alanine aminotransferase activities. The cytotoxicity of itraconazole was enhanced when incubated with hepatocytes pretreated with SKF 525A. SKF 525A had no effects on the cytotoxicity of fluconazole. Curcumin failed to either increase or decrease the cytotoxicity of both antifungal drugs. ATP levels also showed significant decrease in both itraconazole and fluconazole incubated hepatocytes. However, SKF 525A pretreated hepatocytes had significantly lower ATP levels after itraconazole incubations. Collectively, these results confirm the involvement of cytochrome P450 in the cytoprotection in itraconazole induced hepatocyte toxicity. Differences of the effects of SKF 525A on the cytotoxicity induced by itraconazole and fluconazole may be due to the differences on the metabolism of each antifungal drug in vivo.

  10. Effects of clofibric acid on mRNA expression profiles in primary cultures of rat, mouse and human hepatocytes.

    Science.gov (United States)

    Richert, Lysiane; Lamboley, Christelle; Viollon-Abadie, Catherine; Grass, Peter; Hartmann, Nicole; Laurent, Stephane; Heyd, Bruno; Mantion, Georges; Chibout, Salah-Dine; Staedtler, Frank

    2003-09-01

    The mRNA expression profile in control and clofibric acid (CLO)-treated mouse, rat, and human hepatocytes was analyzed using species-specific oligonucleotide DNA microarrays (Affymetrix). A statistical empirical Bayes procedure was applied in order to select the significantly differentially expressed genes. Treatment with the peroxisome proliferator CLO induced up-regulation of genes involved in peroxisome proliferation and in cell proliferation as well as down-regulation of genes involved in apoptosis in hepatocytes of rodent but not of human origin. CLO treatment induced up-regulation of microsomal cytochrome P450 4a genes in rodent hepatocytes and in two of six human hepatocyte cultures. In addition, genes encoding phenobarbital-inducible cytochrome P450s were also up-regulated by CLO in rodent and human hepatocyte cultures. Up-regulation of phenobarbital-inducible UDP-glucuronosyl-transferase genes by CLO was observed in both rat and human but not in mouse hepatocytes. CLO treatment induced up-regulation of L-fatty acid binding protein (L-FABP) gene in hepatocytes of both rodent and human origin. However, while genes of the cytosolic, microsomal, and mitochondrial pathways involved in fatty acid transport and metabolism were up-regulated by CLO in both rodent and human hepatocyte cultures, genes of the peroxisomal pathway of lipid metabolism were up-regulated in rodents only. An up-regulation of hepatocyte nuclear factor 1alpha (HNF1alpha) by CLO was observed only in human hepatocyte cultures, suggesting that this trans-activating factor may play a key role in the regulation of fatty acid metabolism in human liver as well as in the nonresponsiveness of human liver to CLO-induced regulation of cell proliferation and apoptosis.

  11. Effects of clofibric acid on mRNA expression profiles in primary cultures of rat, mouse and human hepatocytes

    International Nuclear Information System (INIS)

    Richert, Lysiane; Lamboley, Christelle; Viollon-Abadie, Catherine; Grass, Peter; Hartmann, Nicole; Laurent, Stephane; Heyd, Bruno; Mantion, Georges; Chibout, Salah-Dine; Staedtler, Frank

    2003-01-01

    The mRNA expression profile in control and clofibric acid (CLO)-treated mouse, rat, and human hepatocytes was analyzed using species-specific oligonucleotide DNA microarrays (Affymetrix). A statistical empirical Bayes procedure was applied in order to select the significantly differentially expressed genes. Treatment with the peroxisome proliferator CLO induced up-regulation of genes involved in peroxisome proliferation and in cell proliferation as well as down-regulation of genes involved in apoptosis in hepatocytes of rodent but not of human origin. CLO treatment induced up-regulation of microsomal cytochrome P450 4a genes in rodent hepatocytes and in two of six human hepatocyte cultures. In addition, genes encoding phenobarbital-inducible cytochrome P450s were also up-regulated by CLO in rodent and human hepatocyte cultures. Up-regulation of phenobarbital-inducible UDP-glucuronosyl-transferase genes by CLO was observed in both rat and human but not in mouse hepatocytes. CLO treatment induced up-regulation of L-fatty acid binding protein (L-FABP) gene in hepatocytes of both rodent and human origin. However, while genes of the cytosolic, microsomal, and mitochondrial pathways involved in fatty acid transport and metabolism were up-regulated by CLO in both rodent and human hepatocyte cultures, genes of the peroxisomal pathway of lipid metabolism were up-regulated in rodents only. An up-regulation of hepatocyte nuclear factor 1α (HNF1α) by CLO was observed only in human hepatocyte cultures, suggesting that this trans-activating factor may play a key role in the regulation of fatty acid metabolism in human liver as well as in the nonresponsiveness of human liver to CLO-induced regulation of cell proliferation and apoptosis

  12. 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.

  13. EXPERIMENTAL SUBSTANTIATION OF PERMEABILIZED HEPATOCYTES MODEL FOR INVESTIGATION OF MITOCHONDRIA IN SITU RESPIRATION.

    Science.gov (United States)

    Merlavsky, V M; Manko, B O; Ikkert, O V; Manko, V V

    2015-01-01

    To verify experimentally the model of permeabilized hepatocytes, the degree of cell permeability was assessed using trypan blue and polarographycally determined cell respiration rate upon succinate (0.35 mM) and a-ketoglutarate (1 mM) oxidation. Oxidative phosphorylation was stimulated by ADP (750 μM). Hepatocyte permeabilization depends on digitonin concentraion in medium and on the number of cells in suspension. Thus, the permeabilization of 0.9-1.7 million cells/ml was completed by 25 μg/ml of digitonin, permeabilization of 2.0-3.0 million cells/ml--by 50 μg/ml of digitonin and permeabilization of 4.0-5.6 million cells/ml--by 100 μg/ml. Thus, the higher is the suspension density, the higher digitonin concentration is required. Treatment of hepatocytes with digitonin resulted in a decrease of endogenous respiration rate to a minimum upon 20-22 μg of digitonin per 1 million cells. Supplementation of permeabilized hepatocytes with α-ketoglutarate maintained stable respiration rate, on the level higher than endogenous respiration at the corresponding digitonin concentration, unlike the intact cells. Respiration rate of permeabilized hepatocytes at the simultaneous addition of α-ketoglutarate and ADP increased to the level of intact cell respiration, irrespective of digitonin concentration. Addition of solely succinate and especially succinate plus ADP markedly intensified the respiration of permeabilized hepatocytes to the level higher than that of intact cells. The dependence of succinate-stimulated respiration on digitonin concentration reached maximum at 20-22 αg of digitonin per 1 million cells. Optimal ratio of digitonin amount and the cell number in suspension is expected to be different in various tissues.

  14. E4orf1 improves lipid and glucose metabolism in hepatocytes: a template to improve steatosis & hyperglycemia.

    Science.gov (United States)

    Dhurandhar, Emily J; Krishnapuram, Rashmi; Hegde, Vijay; Dubuisson, Olga; Tao, Rongya; Dong, X Charlie; Ye, Jianping; Dhurandhar, Nikhil V

    2012-01-01

    Hepatic steatosis often accompanies obesity and insulin resistance. The cornerstones of steatosis treatment include reducing body weight and dietary fat intake, which are marginally successful over the long term. Ad36, a human adenovirus, may offer a template to overcome these limitations. In vitro and in vivo studies collectively indicate that via its E4orf1 protein, Ad36 improves hyperglycemia, and attenuates hepatic steatosis, despite a high fat diet and without weight loss. Considering that hepatic insulin sensitivity, or the synthesis, oxidation, or export of fatty acid by hepatocytes are the key determinant of hepatic lipid storage, we determined the role of E4orf1 protein in modulating these physiological pathways. For this study, HepG2 cells, or mouse primary hepatocytes were transfected with E4orf1 or the null vector. Glucose output by hepatocytes was determined under gluconeogenic conditions (cAMP and dexamethasone, or glucagon exposure). Also, de-novo lipogenesis, palmitate oxidation, and lipid export as determined by apoB secretion were measured 48 h post transfection. Results show that compared to null vector transfected cells, E4orf1 significantly reduced glucose output in basal and gluconeogenic conditions. E4orf1 reduced de-novo lipogenesis by about 35%, increased complete fatty acid oxidation 2-fold (pE4orf1 transfection was in agreement with these findings. Thus, E4orf1 offers a valuable template to exogenously modulate hepatic glucose and lipid metabolism. Elucidating the underlying molecular mechanism may help develop therapeutic approaches for treating diabetes or non-alcoholic fatty liver disease(NAFLD).

  15. Non-viral ex vivo hepatic gene transfer by in situ lipofection of liver and intraperitoneal transplantation of hepatocytes.

    Science.gov (United States)

    Rangarajan, P N; Vatsala, P G; Ashok, M S; Srinivas, V K; Habibullah, C M; Padmanaban, G

    1997-04-29

    Perfusion of liver with plasmid DNA-lipofectin complexes via the portal vein results in efficient accumulation of the vector in hepatocytes. Such hepatocytes, when administered intraperitoneally into a hepatectomized rat, repopulate the liver and express the transgene efficiently. This procedure obviates the need for large-scale hepatocyte culture for ex vivo gene transfer. Further, intraperitoneal transplantation is a simple and cost-effective strategy of introducing genetically modified hepatocytes into liver. Thus, in situ lipofection of liver and intraperitoneal transfer of hepatocytes can be developed into a novel method of non-viral ex vivo gene transfer technique that has applications in the treatment of metabolic disorders of liver and hepatic gene therapy.

  16. Aesthetic skin branding: a novel form of body art with adverse clinical sequela.

    Science.gov (United States)

    Karamanoukian, Raffy; Ukatu, Chidi; Lee, Edward; Hyman, Josh; Sundine, Michael; Kobayashi, Mark; Evans, Gregory R D

    2006-01-01

    Branding is a form of body art wherein third-degree burns are inflicted on the skin to produce permanent scars. This method of scarification is a common practice among many indigenous cultures and has become exceedingly common in western societies. As with other forms of body art, branding is not a manifestation of a psychiatric disorder but, rather, a method of self-expression. The process can be performed through the use of electrocautery, laser, chemicals, freezing, and hot metal. Complications arising from the procedure include acute infection, transmission of blood-borne pathogens, allergic reactions, and sequelae arising from third-degree burns. In addition, skin branding has been shown to be associated with substance abuse and high-risk behaviors among adolescents. The purpose of this article is to present the following case report and review to familiarize clinicians with this dangerous method of body art.

  17. Microencapsulation of Hepatocytes and Mesenchymal Stem Cells for Therapeutic Applications.

    Science.gov (United States)

    Meier, Raphael P H; Montanari, Elisa; Morel, Philippe; Pimenta, Joël; Schuurman, Henk-Jan; Wandrey, Christine; Gerber-Lemaire, Sandrine; Mahou, Redouan; Bühler, Leo H

    2017-01-01

    Encapsulated hepatocyte transplantation and encapsulated mesenchymal stem cell transplantation are newly developed potential treatments for acute and chronic liver diseases, respectively. Cells are microencapsulated in biocompatible semipermeable alginate-based hydrogels. Microspheres protect cells against antibodies and immune cells, while allowing nutrients, small/medium size proteins and drugs to diffuse inside and outside the polymer matrix. Microencapsulated cells are assessed in vitro and designed for experimental transplantation and for future clinical applications.Here, we describe the protocol for microencapsulation of hepatocytes and mesenchymal stem cells within hybrid poly(ethylene glycol)-alginate hydrogels.

  18. Hepatocyte transplantation improves early survival after partial hepatic resection and irradiation

    International Nuclear Information System (INIS)

    Guha, C.; Sharma, A.; Alfieri, A.; Guha, U.; Sokhi, R.; Gagandeep, S.; Gupta, S.; Vikram, B.; RoyChowdhury, J.

    1997-01-01

    Purpose: Radiation therapy (RT) is limited in its role as an adjuvant therapy of intrahepatic malignancies because of lower tolerance of human liver to irradiation (TD (5(5)) -TD (50(5)) ∼ 30-40 Gy). Although, surgical resection of primary or metastatic hepatic tumors has been shown to prolong survival, it is often limited by the presence of residual disease. RT could potentially improve survival of patients with positive surgical margins. However, radiation damage to the liver may be enhanced by hepatocellular proliferation induced by partial hepatic (PH) resection. We hypothesize that hepatocyte transplantation would be able to provide metabolic support and modulate the development of radiation-induced liver disease post-resection. The present study was designed to test the potential of hepatocyte transplantation in modifying the outcome of hepatocellular damage induced by PH and RT. Methods: Adult male Fischer 344 rats (Charles River) received hepatic irradiation of 50 Gy in a single fraction, after surgical exposure and shielding of the stomach and intestine, using a 320 MGC Philips orthovoltage unit. Immediately following irradiation, a two-third partial hepatectomy was performed. Four days post-radiation, the treatment group was injected with 5 x 10 6 syngeneic hepatocytes into the splenic pulp after a left subcostal incision, which allows homogeneous liver engraftment of the transplanted hepatocytes. Hematoxylin and eosin stains of liver biopsies, performed at various time points (3 days, 1, 2, 3 weeks or, anytime when animals died) were used for histologic evaluation. Time-adjusted survival was calculated from the date of irradiation by the product-limit Kaplan-Meier method, adjusting the denominator at every time point for the number of rats at risk. Results: Eight weeks after RT, 30% (n = 11) of the control animals (PH + 50 Gy) were alive compared to 100% (n = 9) of the transplant recipients (p <0.05). The median survival of the control group was 15

  19. Homocysteine inhibits hepatocyte proliferation via endoplasmic reticulum stress.

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    Xue Yu

    Full Text Available Homocysteine is an independent risk factor for coronary, cerebral, and peripheral vascular diseases. Recent studies have shown that levels of homocysteine are elevated in patients with impaired hepatic function, but the precise role of homocysteine in the development of hepatic dysfunction is unclear. In this study, we examined the effect of homocysteine on hepatocyte proliferation in vitro. Our results demonstrated that homocysteine inhibited hepatocyte proliferation by up-regulating protein levels of p53 as well as mRNA and protein levels of p21(Cip1 in primary cultured hepatocytes. Homocysteine induced cell growth arrest in p53-positive hepatocarcinoma cell line HepG2, but not in p53-null hepatocarcinoma cell line Hep3B. A p53 inhibitor pifithrin-α inhibited the expression of p21(Cip1 and attenuated homocysteine-induced cell growth arrest. Homocysteine induced TRB3 expression via endoplasmic reticulum stress pathway, resulting in Akt dephosphorylation. Knock-down of endogenous TRB3 significantly suppressed the inhibitory effect of homocysteine on cell proliferation and the phosphorylation of Akt. LiCl reversed homocysteine-mediated cell growth arrest by inhibiting TRB3-mediated Akt dephosphorylation. These results demonstrate that both TRB3 and p21(Cip1 are critical molecules in the homocysteine signaling cascade and provide a mechanistic explanation for impairment of liver regeneration in hyperhomocysteinemia.

  20. Evaluation and optimization of hepatocyte culture media factors by design of experiments (DoE) methodology.

    Science.gov (United States)

    Dong, Jia; Mandenius, Carl-Fredrik; Lübberstedt, Marc; Urbaniak, Thomas; Nüssler, Andreas K N; Knobeloch, Daniel; Gerlach, Jörg C; Zeilinger, Katrin

    2008-07-01

    Optimization of cell culture media based on statistical experimental design methodology is a widely used approach for improving cultivation conditions. We applied this methodology to refine the composition of an established culture medium for growth of a human hepatoma cell line, C3A. A selection of growth factors and nutrient supplements were systematically screened according to standard design of experiments (DoE) procedures. The results of the screening indicated that the medium additives hepatocyte growth factor, oncostatin M, and fibroblast growth factor 4 significantly influenced the metabolic activities of the C3A cell line. Surface response methodology revealed that the optimum levels for these factors were 30 ng/ml for hepatocyte growth factor and 35 ng/ml for oncostatin M. Additional experiments on primary human hepatocyte cultures showed high variance in metabolic activities between cells from different individuals, making determination of optimal levels of factors more difficult. Still, it was possible to conclude that hepatocyte growth factor, epidermal growth factor, and oncostatin M had decisive effects on the metabolic functions of primary human hepatocytes.

  1. Uptake and disposition of mirex in hepatocytes and subcellular fractions in CD1 mouse liver

    International Nuclear Information System (INIS)

    Charles, A.K.; Rosenbaum, D.P.; Ashok, L.; Abraham, R.

    1985-01-01

    In vivo uptake and disposition of [ 14 C]mirex by CD1 mouse liver subcellular fractions and cells of different nuclear ploidy were examined following single or multiple doses of mirex injected intraperitoneally. Significant amounts of mirex were rapidly taken up by liver (21-29%), suggesting that liver is one of the primary sites of accumulation of the chemical. Among subcellular fractions, mirex was predominantly distributed in mitochondria and microsomes in the irreversibly bound form (about 20%), although its levels fluctuated considerably with time. Mirex was completely dissociated with trichloroacetic acid treatment from both nuclear and plasma membrane fractions, although the total uptake by these fractions was markedly high. The time course of uptake and concentration-dependent disposition of mirex revealed that polyploid hepatocytes selectively accumulated higher amounts of the chemical (two to three times) compared to diploid hepatocytes. The increased affinity of polyploid cells to mirex may indicate a greater susceptibility of this cell type to the chemical insult and also may suggest a possible early involvement of polyploids in the tumorigenic process in rodent livers

  2. Hepatitis E Virus Induces Hepatocyte Apoptosis via Mitochondrial Pathway in Mongolian Gerbils

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    Yifei Yang

    2018-03-01

    Full Text Available Previous studies demonstrated that Mongolian gerbils can be infected by hepatitis E virus (HEV, which induces the hepatic injury. Here, the mitochondria in hepatocytes from HEV-infected gerbils were considerably swollen, thin cristae. After HEV infection, the activity of superoxide dismutase significantly decreased (p < 0.01, while malondialdehyde concentrations significantly increased, compared with those in the control group (p < 0.01. Adenosine triphosphatase levels decreased significantly in the hepatocyte of the inoculated groups, compared with those in control group (p < 0.05 at days 21, 28, 42 post-inoculation (dpi as well. Furthermore, the levels of ATP synthetase ATP5A1 significantly decreased during HEV infection, compared with those in the control group (p < 0.05. According to the TdT mediated dUTP nick end labeling (TUNEL detection, TUNEL positive hepatocytes increased in the inoculated group, compared with that in the control group (p < 0.05. Up-regulation of the mitochondrion-mediated apoptosis regulating proteins, Bax and Bcl-2, in the HEV-infected gerbils (p < 0.05 was observed. However, cytochrome c levels in mitochondria decreased, while this molecule was detected in the cytoplasm of the infected animals, in contrast to that in the control group. Apaf-1, and active caspase-9 and -3 levels were shown to be significantly higher in the inoculated group compared with those in the control group (p < 0.05. Taken together, our results demonstrated that HEV infection induces hepatocyte injuries and activity of the mitochondrial apoptotic pathway, which trigger the hepatocyte apoptosis in Mongolian gerbils.

  3. Glucose production and storage in hepatocytes isolated from normal versus diabetic rats

    International Nuclear Information System (INIS)

    Olivieri, M.C.; Dragland-Meserve, C.J.; Parker Botelho, L.H.

    1987-01-01

    The rates of glucose production and storage were compared in hepatocytes isolated from normal versus insulin-resistant diabetic rats. A single low-dose (40 mg/kg) IV injection of streptozotocin to 250 g rats resulted in a Type II diabetic animal model which was hyperglycemic with normal insulin levels. Addition of 8 mM 14 C-lactate and 2 mM pyruvate to hepatocytes resulted in a linear increase in total glucose production ( 14 C-glucose and unlabeled glucose) and incorporation into glycogen measured over 120 min. The rate of gluconeogenesis was estimated from the production of 14 C-glucose and the rate of glycogenolysis was estimated from the production of unlabeled glucose in cells incubated in the presence or absence of 14 C-labelled substrate. There was not significant difference in total glucose production in hepatocytes isolated from normal versus diabetic rats, however, the contribution from gluconeogenesis versus glycogenolysis was significantly different. Following a 1 h incubation of cells from normal rats, 42% of the total glucose production was due to gluconeogenesis and 58% was due to glycogenolysis. In cells from diabetic rats, 83% of total glucose production was from gluconeogenesis and 17% from glycogenolysis. Also, incubation with 14 C-lactate/pyruvate resulted in a 3.3-fold increase in 14 C-glucose incorporation into glycogen in hepatocytes isolated from normal rats compared to diabetic rats. These data suggest that alterations occur in the rate-limiting enzymes responsible for glucose production and storage in hepatocytes isolated from a rat model of insulin-resistant Type II diabetes

  4. Endothelial cell-derived matrix promotes the metabolic functional maturation of hepatocyte via integrin-Src signalling.

    Science.gov (United States)

    Guo, Xinyue; Li, Weihong; Ma, Minghui; Lu, Xin; Zhang, Haiyan

    2017-11-01

    The extracellular matrix (ECM) microenvironment is involved in the regulation of hepatocyte phenotype and function. Recently, the cell-derived extracellular matrix has been proposed to represent the bioactive and biocompatible materials of the native ECM. Here, we show that the endothelial cell-derived matrix (EC matrix) promotes the metabolic maturation of human adipose stem cell-derived hepatocyte-like cells (hASC-HLCs) through the activation of the transcription factor forkhead box protein A2 (FOXA2) and the nuclear receptors hepatocyte nuclear factor 4 alpha (HNF4α) and pregnane X receptor (PXR). Reducing the fibronectin content in the EC matrix or silencing the expression of α5 integrin in the hASC-HLCs inhibited the effect of the EC matrix on Src phosphorylation and hepatocyte maturation. The inhibition of Src phosphorylation using the inhibitor PP2 or silencing the expression of Src in hASC-HLCs also attenuated the up-regulation of the metabolic function of hASC-HLCs in a nuclear receptor-dependent manner. These data elucidate integrin-Src signalling linking the extrinsic EC matrix signals and metabolic functional maturation of hepatocyte. This study provides a model for studying the interaction between hepatocytes and non-parenchymal cell-derived matrix. © 2017 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  5. Protective effects of melittin on transforming growth factor-β1 injury to hepatocytes via anti-apoptotic mechanism

    International Nuclear Information System (INIS)

    Lee, Woo-Ram; Park, Ji-Hyun; Kim, Kyung-Hyun; Park, Yoon-Yub; Han, Sang-Mi; Park, Kwan-kyu

    2011-01-01

    Melittin is a cationic, hemolytic peptide that is the main toxic component in the venom of the honey bee (Apis mellifera). Melittin has multiple effects, including anti-bacterial, anti-viral and anti-inflammatory, in various cell types. However, the anti-apoptotic mechanisms of melittin have not been fully elucidated in hepatocytes. Apoptosis contributes to liver inflammation and fibrosis. Knowledge of the apoptotic mechanisms is important to develop new and effective therapies for treatment of cirrhosis, portal hypertension, liver cancer, and other liver diseases. In the present study, we investigated the anti-apoptotic effect of melittin on transforming growth factor (TGF)-β1-induced apoptosis in hepatocytes. TGF-β1-treated hepatocytes were exposed to low doses (0.5 and 1 μg/mL) and high dose (2 μg/mL) of melittin. The low doses significantly protected these cells from DNA damage in TGF-β1-induced apoptosis compared to the high dose. Also, melittin suppressed TGF-β1-induced apoptotic activation of the Bcl-2 family and caspase family of proteins, which resulted in the inhibition of poly-ADP-ribose polymerase (PARP) cleavage. These results demonstrate that TGF-β1 induces hepatocyte apoptosis and that an optimal dose of melittin exerts anti-apoptotic effects against TGF-β1-induced injury to hepatocytes via the mitochondrial pathway. These results suggest that an optimal dose of melittin can serve to protect cells against TGF-β1-mediated injury. - Highlights: → We investigated the anti-apoptotic effect of melittin on TGF-β1-induced hepatocyte. → TGF-β1 induces hepatocyte apoptosis. → TGF-β1-treated hepatocytes were exposed to low doses and high dose of melittin. → Optimal dose of melittin exerts anti-apoptotic effects to hepatocytes.

  6. AR42J-B-13 cell: An expandable progenitor to generate an unlimited supply of functional hepatocytes

    International Nuclear Information System (INIS)

    Wallace, Karen; Fairhall, Emma A.; Charlton, Keith A.; Wright, Matthew C.

    2010-01-01

    Hepatocytes are the preparation of choice for Toxicological research in vitro. However, despite the fact that hepatocytes proliferate in vivo during liver regeneration, they are resistant to proliferation in vitro, do not tolerate sub-culture and tend to enter a de-differentiation program that results in a loss of hepatic function. These limitations have resulted in the search for expandable rodent and human cells capable of being directed to differentiate into functional hepatocytes. Research with stem cells suggests that it may be possible to provide the research community with hepatocytes in vitro although to date, significant challenges remain, notably generating a sufficiently pure population of hepatocytes with a quantitative functionality comparable with hepatocytes. This paper reviews work with the AR42J-B-13 (B-13) cell line. The B-13 cell was cloned from the rodent AR42J pancreatic cell line, express genes associated with pancreatic acinar cells and readily proliferates in simple culture media. When exposed to glucocorticoid, 75-85% of the cells trans-differentiate into hepatocyte-like (B-13/H) cells functioning at a level quantitatively similar to freshly isolated rat hepatocytes (with the remaining cells retaining the B-13 phenotype). Trans-differentiation of pancreatic acinar cells also appears to occur in vivo in rats treated with glucocorticoid; in mice with elevated circulating glucocorticoid and in humans treated for long periods with glucocorticoid. The B-13 response to glucocorticoid therefore appears to be related to a real pathophysiological response of a pancreatic cell to glucocorticoid. An understanding of how this process occurs and if it can be generated or engineered in human cells would result in a cell line with the ability to generate an unlimited supply of functional human hepatocytes in a cost effective manner.

  7. Evolution of the snake body form reveals homoplasy in amniote Hox gene function.

    Science.gov (United States)

    Head, Jason J; Polly, P David

    2015-04-02

    Hox genes regulate regionalization of the axial skeleton in vertebrates, and changes in their expression have been proposed to be a fundamental mechanism driving the evolution of new body forms. The origin of the snake-like body form, with its deregionalized pre-cloacal axial skeleton, has been explained as either homogenization of Hox gene expression domains, or retention of standard vertebrate Hox domains with alteration of downstream expression that suppresses development of distinct regions. Both models assume a highly regionalized ancestor, but the extent of deregionalization of the primaxial domain (vertebrae, dorsal ribs) of the skeleton in snake-like body forms has never been analysed. Here we combine geometric morphometrics and maximum-likelihood analysis to show that the pre-cloacal primaxial domain of elongate, limb-reduced lizards and snakes is not deregionalized compared with limbed taxa, and that the phylogenetic structure of primaxial morphology in reptiles does not support a loss of regionalization in the evolution of snakes. We demonstrate that morphometric regional boundaries correspond to mapped gene expression domains in snakes, suggesting that their primaxial domain is patterned by a normally functional Hox code. Comparison of primaxial osteology in fossil and modern amniotes with Hox gene distributions within Amniota indicates that a functional, sequentially expressed Hox code patterned a subtle morphological gradient along the anterior-posterior axis in stem members of amniote clades and extant lizards, including snakes. The highly regionalized skeletons of extant archosaurs and mammals result from independent evolution in the Hox code and do not represent ancestral conditions for clades with snake-like body forms. The developmental origin of snakes is best explained by decoupling of the primaxial and abaxial domains and by increases in somite number, not by changes in the function of primaxial Hox genes.

  8. Isolation of primary human hepatocytes from normal and diseased liver tissue: a one hundred liver experience.

    Directory of Open Access Journals (Sweden)

    Ricky H Bhogal

    2011-03-01

    Full Text Available Successful and consistent isolation of primary human hepatocytes remains a challenge for both cell-based therapeutics/transplantation and laboratory research. Several centres around the world have extensive experience in the isolation of human hepatocytes from non-diseased livers obtained from donor liver surplus to surgical requirement or at hepatic resection for tumours. These livers are an important but limited source of cells for therapy or research. The capacity to isolate cells from diseased liver tissue removed at transplantation would substantially increase availability of cells for research. However no studies comparing the outcome of human hepatocytes isolation from diseased and non-diseased livers presently exist. Here we report our experience isolating human hepatocytes from organ donors, non-diseased resected liver and cirrhotic tissue. We report the cell yields and functional qualities of cells isolated from the different types of liver and demonstrate that a single rigorous protocol allows the routine harvest of good quality primary hepatocytes from the most commonly accessible human liver tissue samples.

  9. Cytotoxic mechanisms of hydrosulfide anion and cyanide anion in primary rat hepatocyte cultures

    International Nuclear Information System (INIS)

    Thompson, Rodney W.; Valentine, Holly L.; Valentine, William M.

    2003-01-01

    Hydrogen sulfide and hydrogen cyanide are known to compromise mitochondrial respiration through inhibition of cytochrome c oxidase and this is generally considered to be their primary mechanism of toxicity. Experimental studies and the efficiency of current treatment protocols suggest that H 2 S may exert adverse physiological effects through additional mechanisms. To evaluate the role of alternative mechanisms in H 2 S toxicity, the relative contributions of electron transport inhibition, uncoupling of mitochondrial respiration, and opening of the mitochondrial permeability transition pore (MPTP) to hydrosulfide and cyanide anion cytotoxicity in primary hepatocyte cultures were examined. Supplementation of hepatocytes with the glycolytic substrate, fructose, rescued hepatocytes from cyanide anion induced toxicity, whereas fructose supplementation increased hydrosulfide anion toxicity suggesting that hydrosulfide anion may compromise glycolysis in hepatocytes. Although inhibitors of the MPTP opening were protective for hydrosulfide anion, they had no effect on cyanide anion toxicity, consistent with an involvement of the permeability transition pore in hydrosulfide anion toxicity but not cyanide anion toxicity. Exposure of isolated rat liver mitochondria to hydrosulfide did not result in large amplitude swelling suggesting that if H 2 S induces the permeability transition it does so indirectly through a mechanism requiring other cellular components. Hydrosulfide anion did not appear to be an uncoupler of mitochondrial respiration in hepatocytes based upon the inability of oligomycin and fructose to protect hepatocytes from hydrosulfide anion toxicity. These findings support mechanisms additional to inhibition of cytochrome c oxidase in hydrogen sulfide toxicity. Further investigations are required to assess the role of the permeability transition in H 2 S toxicity, determine whether similar affects occur in other cell types or in vivo and evaluate whether this may

  10. Deletion of hepatocyte nuclear factor-1-beta in an infant with prune belly syndrome.

    Science.gov (United States)

    Haeri, Sina; Devers, Patricia L; Kaiser-Rogers, Kathleen A; Moylan, Vincent J; Torchia, Beth S; Horton, Amanda L; Wolfe, Honor M; Aylsworth, Arthur S

    2010-08-01

    Prune belly syndrome is a rare congenital disorder characterized by deficiency of abdominal wall muscles, cryptorchidism, and urinary tract anomalies. We have had the opportunity to study a baby with prune belly syndrome associated with an apparently de novo 1.3-megabase interstitial 17q12 microdeletion that includes the hepatocyte nuclear factor-1-beta gene at 17q12. One previous patient, an adult, has been reported with prune belly syndrome and a hepatocyte nuclear factor-1-beta microdeletion. Hepatocyte nuclear factor-1-beta is a widely expressed transcription factor that regulates tissue-specific gene expression and is expressed in numerous tissues including mesonephric duct derivatives, the renal tubule of the metanephros, and the developing prostate of the mouse. Mutations in hepatocyte nuclear factor-1-beta cause the "renal cysts and diabetes syndrome," isolated renal cystic dysplasia, and a variety of other malformations. Based on its expression pattern and the observation of two affected cases, we propose that haploinsufficiency of hepatocyte nuclear factor-1-beta may be causally related to the production of the prune belly syndrome phenotype through a mechanism of prostatic and ureteral hypoplasia that results in severe obstructive uropathy with urinary tract and abdominal distension. Copyright Thieme Medical Publishers.

  11. Swelling of rat hepatocytes stimulates glycogen synthesis

    NARCIS (Netherlands)

    Baquet, A.; Hue, L.; Meijer, A. J.; van Woerkom, G. M.; Plomp, P. J.

    1990-01-01

    In hepatocytes from fasted rats, several amino acids are known to stimulate glycogen synthesis via activation of glycogen synthase. The hypothesis that an increase in cell volume resulting from amino acid uptake may be involved in the stimulation of glycogen synthesis is supported by the following

  12. Total body irradiation as a form of preparation for bone marrow transplantation

    International Nuclear Information System (INIS)

    Inoue, Toshihiko

    1987-01-01

    The history of total body irradiation and bone marrow transplantation is surprisingly old. Following the success of Thomas et al. in the 1970s, bone marrow transplantation appeared to be the sole curative treatment modality for high-risk leukemia. A supralethal dose of total body irradiation was widely accepted as a form of preparation for bone marrow transplantation. In this paper, I described the present status of bone marrow transplantation for leukemia patients in Japan based on the IVth national survey. Since interstitial pneumonitis was one of the most life threatening complications after bone marrow transplantation, I mentioned the dose, dose-rate and fraction of total body irradiation in more detail. In addition, I dealt with some problems of the total body irradiation, such as dose prescription, compensating contour as well as inhomogeneity, and shielding for the highrisk organs. (author) 82 refs

  13. Vitamin A and feeding statuses modulate the insulin-regulated gene expression in Zucker lean and fatty primary rat hepatocytes.

    Directory of Open Access Journals (Sweden)

    Wei Chen

    Full Text Available Unattended hepatic insulin resistance predisposes individuals to dyslipidemia, type 2 diabetes and many other metabolic complications. The mechanism of hepatic insulin resistance at the gene expression level remains unrevealed. To examine the effects of vitamin A (VA, total energy intake and feeding conditions on the insulin-regulated gene expression in primary hepatocytes of Zucker lean (ZL and fatty (ZF rats, we analyze the expression levels of hepatic model genes in response to the treatments of insulin and retinoic acid (RA. We report that the insulin- and RA-regulated glucokinase, sterol regulatory element-binding protein-1c and cytosolic form of phosphoenolpyruvate carboxykinase expressions are impaired in hepatocytes of ZF rats fed chow or a VA sufficient (VAS diet ad libitum. The impairments are partially corrected when ZF rats are fed a VA deficient (VAD diet ad libitum or pair-fed a VAS diet to the intake of their VAD counterparts in non-fasting conditions. Interestingly in the pair-fed ZL and ZF rats, transient overeating on the last day of pair-feeding regimen changes the expression levels of some VA catabolic genes, and impairs the insulin- and RA-regulated gene expression in hepatocytes. These results demonstrate that VA and feeding statuses modulate the hepatic insulin sensitivity at the gene expression level.

  14. 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.

  15. Retroviral-mediated gene transfer and expression of human phenylalanine hydroxylase in primary mouse hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Peng, H.; Armentano, D.; Mackenzie-Graham, L.; Shen, R.F.; Darlington, G.; Ledley, F.D.; Woo, S.L.C. (Baylor College of Medicine, Houston, TX (USA))

    1988-11-01

    Genetic therapy for phenylketonuria (severe phenylalanine hydroxylase deficiency) may require introduction of a normal phenylalanine hydroxylase gene into hepatic cells of patients. The authors report development of a recombinant retrovirus based on the N2 vector for gene transfer and expression of human phenylalanine hydroxylase cDNA in primary mouse hepatocytes. This construct contains an internal promoter of the human {alpha}{sub 1}-antitrypsin gene driving transcription of the phenylalanine hydroxylase cDNA. Primary mouse hepatocytes were isolated from newborn mice, infected with the recombinant virus, and selected for expression of the neomycin-resistance gene. Hepatocytes transformed with the recombinant virus contained high levels of human phenylalanine hydroxylase mRNA transcripts originating from the retroviral and internal promoters. These results demonstrate that the transcriptional regulatory elements of the {alpha}{sub 1} antitrypsin gene retain their tissue-specific function in the recombinant provirus and establish a method for efficient transfer and high-level expression of human phenylalanine hydroxylase in primary hepatocytes.

  16. Retroviral-mediated gene transfer and expression of human phenylalanine hydroxylase in primary mouse hepatocytes

    International Nuclear Information System (INIS)

    Peng, H.; Armentano, D.; Mackenzie-Graham, L.; Shen, R.F.; Darlington, G.; Ledley, F.D.; Woo, S.L.C.

    1988-01-01

    Genetic therapy for phenylketonuria (severe phenylalanine hydroxylase deficiency) may require introduction of a normal phenylalanine hydroxylase gene into hepatic cells of patients. The authors report development of a recombinant retrovirus based on the N2 vector for gene transfer and expression of human phenylalanine hydroxylase cDNA in primary mouse hepatocytes. This construct contains an internal promoter of the human α 1 -antitrypsin gene driving transcription of the phenylalanine hydroxylase cDNA. Primary mouse hepatocytes were isolated from newborn mice, infected with the recombinant virus, and selected for expression of the neomycin-resistance gene. Hepatocytes transformed with the recombinant virus contained high levels of human phenylalanine hydroxylase mRNA transcripts originating from the retroviral and internal promoters. These results demonstrate that the transcriptional regulatory elements of the α 1 antitrypsin gene retain their tissue-specific function in the recombinant provirus and establish a method for efficient transfer and high-level expression of human phenylalanine hydroxylase in primary hepatocytes

  17. Lean Body Mass Harbors Sensing Mechanisms that Allow Safeguarding of Methionine Homeostasis.

    Science.gov (United States)

    Ingenbleek, Yves

    2017-09-20

    Protein-depleted states generate allosteric inhibition of liver cystathionine β-synthase (CBS), which governs the first enzymatic step of the transsulfuration cascade, resulting in upstream accretion of homocysteine (Hcy) in body fluids. A similar Hcy increase may arise from normal hepatocytes undergoing experimentally-induced impairment of betaine-homocysteine methyltransferase (BHTM) activity or from components of lean body mass (LBM) submitted to any inflammatory disorder. LBM comprises a composite agglomeration of extrarenal tissues characterized by naturally occurring BHTM inactivity. As a result of cellular injury, LBM releases high concentrations of Hcy into the extracellular space, contrasting with the disruption of normal remethylation pathways. Hyperhomocysteinemia acts as a biomarker, reflecting the severity of insult and operating as an alarm signal. Elevated Hcy levels constitute a precursor pool recognized by a CBS coding region that reacts to meet increased methionine requirements in LBM tissues, using its enhanced production in hepatocytes. Preservation of methionine homeostasis benefits from its high metabolic priority and survival value.

  18. Lean Body Mass Harbors Sensing Mechanisms that Allow Safeguarding of Methionine Homeostasis

    Directory of Open Access Journals (Sweden)

    Yves Ingenbleek

    2017-09-01

    Full Text Available Protein-depleted states generate allosteric inhibition of liver cystathionine β-synthase (CBS, which governs the first enzymatic step of the transsulfuration cascade, resulting in upstream accretion of homocysteine (Hcy in body fluids. A similar Hcy increase may arise from normal hepatocytes undergoing experimentally-induced impairment of betaine-homocysteine methyltransferase (BHTM activity or from components of lean body mass (LBM submitted to any inflammatory disorder. LBM comprises a composite agglomeration of extrarenal tissues characterized by naturally occurring BHTM inactivity. As a result of cellular injury, LBM releases high concentrations of Hcy into the extracellular space, contrasting with the disruption of normal remethylation pathways. Hyperhomocysteinemia acts as a biomarker, reflecting the severity of insult and operating as an alarm signal. Elevated Hcy levels constitute a precursor pool recognized by a CBS coding region that reacts to meet increased methionine requirements in LBM tissues, using its enhanced production in hepatocytes. Preservation of methionine homeostasis benefits from its high metabolic priority and survival value.

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

    International Nuclear Information System (INIS)

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

    2012-01-01

    Highlights: ► cAMP blocks cell death induced by TNF and actinomycin D in cultured hepatocytes. ► cAMP blocks NF-κB activation induced by TNF and actinomycin D. ► cAMP blocks DISC formation following TNF and actinomycin D exposure. ► cAMP blocks TNF signaling at a proximal step. -- Abstract: 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

  20. 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

  1. Ferritin expression in rat hepatocytes and Kupffer cells after lead nitrate treatment.

    Science.gov (United States)

    Fan, Yang; Yamada, Toshiyuki; Shimizu, Takeshi; Nanashima, Naoki; Akita, Miki; Suto, Kohji; Tsuchida, Shigeki

    2009-02-01

    Lead nitrate induces hepatocyte proliferation and subsequent apoptosis in rat livers. Iron is a constituent of heme and is also required for cell proliferation. In this study, the expression of ferritin light-chain (FTL), the major iron storage protein, was investigated in rat livers after a single intravenous injection of lead nitrate. Western blotting and immunohistochemistry revealed that FTL was increased in hepatocytes around the central veins and strongly expressed in nonparenchymal cells. Some FTL-positive nonparenchymal cells were identified as Kupffer cells that were positive for CD68. FTL-positive Kupffer cells occupied about 60% of CD68-positive cells in the periportal and perivenous areas. The relationships between FTL expression and apoptosis induction or the engulfment of apoptotic cells were examined. TUNEL-positive cells were increased in the treatment group, and enhanced expression of milk fat globule EGF-like 8 was demonstrated in some Kupffer cells and hepatocytes, indicating enhanced apoptosis induction and phagocytosis of apoptotic cells. FTL-positive Kupffer cells were not detected without lead nitrate treatment or in rat livers treated with clofibrate, which induces hepatocyte proliferation but not apoptosis. These results suggest that FTL expression in Kupffer cells after lead treatment is dependent on phagocytosis of apoptotic cells.

  2. Resveratrol Differentially Regulates NAMPT and SIRT1 in Hepatocarcinoma Cells and Primary Human Hepatocytes

    Science.gov (United States)

    Schuster, Susanne; Penke, Melanie; Gorski, Theresa; Petzold-Quinque, Stefanie; Damm, Georg; Gebhardt, Rolf; Kiess, Wieland; Garten, Antje

    2014-01-01

    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. PMID:24603648

  3. 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.

  4. N-Acetyl-2-Aminofluorene (AAF) Processing in Adult Rat Hepatocytes in Primary Culture Occurs by High-Affinity Low-Velocity and Low-Affinity High-Velocity AAF Metabolite-Forming Systems.

    Science.gov (United States)

    Koch, Katherine S; Moran, Tom; Shier, W Thomas; Leffert, Hyam L

    2018-05-01

    N-acetyl-2-aminofluorene (AAF) is a procarcinogen used widely in physiological investigations of chemical hepatocarcinogenesis. Its metabolic pathways have been described extensively, yet little is known about its biochemical processing, growth cycle expression, and pharmacological properties inside living hepatocytes-the principal cellular targets of this hepatocarcinogen. In this report, primary monolayer adult rat hepatocyte cultures and high specific-activity [ring G-3 H]-N-acetyl-2-aminofluorene were used to extend previous observations of metabolic activation of AAF by highly differentiated, proliferation-competent hepatocytes in long-term cultures. AAF metabolism proceeded by zero-order kinetics. Hepatocytes processed significant amounts of procarcinogen (≈12 μg AAF/106 cells/day). Five ring-hydroxylated and one deacetylated species of AAF were secreted into the culture media. Extracellular metabolite levels varied during the growth cycle (days 0-13), but their rank quantitative order was time invariant: 5-OH-AAF > 7-OH-AAF > 3-OH-AAF > N-OH-AAF > aminofluorene (AF) > 1-OH-AAF. Lineweaver-Burk analyses revealed two principal classes of metabolism: System I (high-affinity and low-velocity), Km[APPARENT] = 1.64 × 10-7  M and VMAX[APPARENT] = 0.1 nmol/106 cells/day and System II (low-affinity and high-velocity), Km[APPARENT] = 3.25 × 10-5  M and VMAX[APPARENT] = 1000 nmol/106 cells/day. A third system of metabolism of AAF to AF, with Km[APPARENT] and VMAX[APPARENT] constants of 9.6 × 10-5  M and 4.7 nmol/106 cells/day, was also observed. Evidence provided in this report and its companion paper suggests selective roles and intracellular locations for System I- and System II-mediated AAF metabolite formation during hepatocarcinogenesis, although some of the molecules and mechanisms responsible for multi-system processing remain to be fully defined.

  5. Optimization of the isolation and cultivation of Cyprinus carpio primary hepatocytes

    OpenAIRE

    Yanhong, Fan; Chenghua, He; Guofang, Liu; Haibin, Zhang

    2008-01-01

    The aquatic environment is affected by numerous chemical contaminants. There is an increasing need to identify these chemicals and to evaluate their potential toxicity towards aquatic life. In this research we optimized techniques for primary cell culture of Cyprinus carpio hepatocytes as one adjunct model for ecotoxicological evaluation of the potential hazards of xenobiotics in the aquatic environment. In this study, Cyprinus carpio hepatocytes were isolated by mechanical separation, two-st...

  6. Magentic Cell labeling of primary and stem cell-derived pig hepatocytes for MRI-based cell tracking of heptocytes transplantation

    Science.gov (United States)

    Pig hepatocytes are an important investigational tool for optimizing hepatocyte transplantation schemes in both allogeneic and xenogeneic transplant scenarios. MRI can be used to serially monitor the transplanted cells, but only if the hepatocytes can be labeled with a magnetic particle. In this wo...

  7. Immortalization of Human Fetal Hepatocyte by Ectopic Expression of Human Telomerase Reverse Transcriptase, Human Papilloma Virus (E7) and Simian Virus 40 Large T (SV40 T) Antigen Towards Bioartificial Liver Support.

    Science.gov (United States)

    Giri, Shibashish; Bader, Augustinus

    2014-09-01

    Generation of genetically stable and non-tumoric immortalization cell line from primary cells would be enormously useful for research and therapeutic purposes, but progress towards this goal has so far been limited. It is now universal acceptance that immortalization of human fetal hepatocytes based on recent advances of telomerase biology and oncogene, lead to unlimited population doubling could be the possible source for bioartificial liver device. Immortalization of human fetal hepatocytes cell line by ectopic expression of human telomerase reverse transcriptase (hTERT), human papilloma virus gene (E7) and simian virus 40 large T (SV40 T) antigens is main goal of present study. We used an inducible system containing human telomerase and E7, both of which are cloned into responder constructs controlled by doxycycline transactivator. We characterized the immortalized human fetal hepatocyte cells by analysis of green fluorescent cells (GFP) positive cells using flow cytometry (FACs) cell sorting and morphology, proliferative rate and antigen expression by immunohistochemical analysis. In addition to we analysized lactate formation, glucose consumption, albumin secretion and urea production of immortalized human fetal hepatocyte cells. After 25 attempts for transfection of adult primary hepatocytes by human telomerase and E7 to immortalize them, none of the transfection systems resulted in the production of a stable, proliferating cell line. Although the transfection efficiency was more than 70% on the first day, the vast majority of the transfected hepatocytes lost their signal within the first 5-7 days. The remaining transfected hepatocytes persisted for 2-4 weeks and divided one or two times without forming a clone. After 10 attempts of transfection human fetal hepatocytes using the same transfection system, we obtained one stable human fetal hepatocytes cell line which was able albumin secretion urea production and glucose consumption. We established a

  8. Activation-dependent mitochondrial translocation of Foxp3 in human hepatocytes

    International Nuclear Information System (INIS)

    Rojas, Joselyn; Teran-Angel, Guillermo; Barbosa, Luisa; Peterson, Darrell L.; Berrueta, Lisbeth; Salmen, Siham

    2016-01-01

    Foxp3 is considered to be the master regulator for the development and function of regulatory T cells (Treg). Recently Foxp3, has been detected in extra lymphoid tissue, and in hepatocytes and has been associated with hepatocellular carcinoma (HCC), although its role has not been defined. Since it is expected that there is a relationship between protein localization, activity and cellular function, the aim of this study was to explore the subcellular localization of Foxp3 in resting and stimulated human hepatocytes. Foxp3 expression was measured by flow cytometry, subcellular fractioning, and immunofluorescence, and this data was used to track the shuttling of Foxp3 in different subcellular compartments in hepatocytes (HepG2 cell line), stimulated by using the PKC activators (PMA), core and preS1/2 antigen from hepatitis B virus (HBV). Our data shows that besides the nuclear location, mitochondrial translocation was detected after stimulation with PMA and at to a lesser extent, with preS1/2. In addition, Foxp3 is localizes at outer mitochondrial membrane. These results suggest a non-canonical role of Foxp3 in the mitochondrial compartment in human hepatocytes, and opens a new field about their role in liver damages during HBV infection. - Highlights: • The expression and subcellular distribution of Foxp3, is modulated by PMA and preS1/2. • PMA and preS1/2 increase Foxp3 expression on HepG2. • PMA and preS1/2 induce foxp3 enrichment at mitochondrial, microsomal and nuclear compartments. • Results suggest a non-canonical function of Foxp3 or a mitochondrial transcriptional activity.

  9. Activation-dependent mitochondrial translocation of Foxp3 in human hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Rojas, Joselyn; Teran-Angel, Guillermo; Barbosa, Luisa [Instituto de Inmunología Clínica, Facultad de Medicina, Universidad de Los Andes, Merida (Venezuela, Bolivarian Republic of); Peterson, Darrell L. [Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, VA (United States); Berrueta, Lisbeth, E-mail: lberruet@ula.ve [Instituto de Inmunología Clínica, Facultad de Medicina, Universidad de Los Andes, Merida (Venezuela, Bolivarian Republic of); Division of Preventive Medicine, Brigham and Women' s Hospital, Harvard Medical School, Boston, MA (United States); Salmen, Siham, E-mail: sihamsa@ula.ve [Instituto de Inmunología Clínica, Facultad de Medicina, Universidad de Los Andes, Merida (Venezuela, Bolivarian Republic of)

    2016-05-01

    Foxp3 is considered to be the master regulator for the development and function of regulatory T cells (Treg). Recently Foxp3, has been detected in extra lymphoid tissue, and in hepatocytes and has been associated with hepatocellular carcinoma (HCC), although its role has not been defined. Since it is expected that there is a relationship between protein localization, activity and cellular function, the aim of this study was to explore the subcellular localization of Foxp3 in resting and stimulated human hepatocytes. Foxp3 expression was measured by flow cytometry, subcellular fractioning, and immunofluorescence, and this data was used to track the shuttling of Foxp3 in different subcellular compartments in hepatocytes (HepG2 cell line), stimulated by using the PKC activators (PMA), core and preS1/2 antigen from hepatitis B virus (HBV). Our data shows that besides the nuclear location, mitochondrial translocation was detected after stimulation with PMA and at to a lesser extent, with preS1/2. In addition, Foxp3 is localizes at outer mitochondrial membrane. These results suggest a non-canonical role of Foxp3 in the mitochondrial compartment in human hepatocytes, and opens a new field about their role in liver damages during HBV infection. - Highlights: • The expression and subcellular distribution of Foxp3, is modulated by PMA and preS1/2. • PMA and preS1/2 increase Foxp3 expression on HepG2. • PMA and preS1/2 induce foxp3 enrichment at mitochondrial, microsomal and nuclear compartments. • Results suggest a non-canonical function of Foxp3 or a mitochondrial transcriptional activity.

  10. Microcystin-LR induces anoikis resistance to the hepatocyte uptake transporter OATP1B3-expressing cell lines

    International Nuclear Information System (INIS)

    Takano, Hiroyuki; Takumi, Shota; Ikema, Satoshi; Mizoue, Nozomi; Hotta, Yuki; Shiozaki, Kazuhiro; Sugiyama, Yasumasa; Furukawa, Tatsuhiko; Komatsu, Masaharu

    2014-01-01

    Microcystin-LR is a cyclic peptide released by several bloom-forming cyanobacteria. Understanding the mechanism of microcystin-LR toxicity is important, because of the both potencies of its acute cytotoxicity and tumor-promoting activity in hepatocytes of animals and humans. Recently, we have reported that the expression of human hepatocyte uptake transporter OATP1B3 was critical for the selective uptake of microcystin-LR into hepatocytes and for induction of its fatal cytotoxicity. In this study, we demonstrated a novel function of microcystin-LR which induced bipotential changes including anoikis resistance and cytoskeleton reorganization to OATP1B3-transfected HEK293 cells (HEK293-OATP1B3). After exposure to microcystin-LR, HEK293-OATP1B3 cells were divided to the floating cells and remaining adherent cells. After collection and reseeding the floating cells into a fresh flask, cells were confluently proliferated (HEK293-OATP1B3-FL) under the microcystin-LR-free condition. Both the proliferated HEK293-OATP1B3-FL and remaining adherent HEK293-OATP1B3-AD cells changed the character with down- and up-regulation of E-cadherin, respectively. Additionally, these cells acquired resistance to microcystin-LR. These results suggest that microcystin-LR could be associated with not only tumor promotion, but also epithelial–mesenchymal transition-mediated cancer metastasis. Furthermore, microcystin-LR might induce the cytoskeleton reorganization be accompanied epithelial–mesenchymal transition

  11. 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. PMID:25285524

  12. 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.

  13. Hepatocyte-based in vitro model for assessment of drug-induced cholestasis

    Energy Technology Data Exchange (ETDEWEB)

    Chatterjee, Sagnik, E-mail: Sagnik.Chatterjee@pharm.kuleuven.be [Drug Delivery and Disposition, KU Leuven Department of Pharmaceutical and Pharmacological Sciences, O and N2, Herestraat 49 — bus 921, 3000 Leuven (Belgium); Richert, Lysiane, E-mail: l.richert@kaly-cell.com [KaLy-Cell, 20A rue du Général Leclerc, 67115 Plobsheim (France); Augustijns, Patrick, E-mail: Patrick.Augustijns@pharm.kuleuven.be [Drug Delivery and Disposition, KU Leuven Department of Pharmaceutical and Pharmacological Sciences, O and N2, Herestraat 49 — bus 921, 3000 Leuven (Belgium); Annaert, Pieter, E-mail: Pieter.Annaert@pharm.kuleuven.be [Drug Delivery and Disposition, KU Leuven Department of Pharmaceutical and Pharmacological Sciences, O and N2, Herestraat 49 — bus 921, 3000 Leuven (Belgium)

    2014-01-01

    Early detection of drug-induced cholestasis remains a challenge during drug development. We have developed and validated a biorelevant sandwich-cultured hepatocytes- (SCH) based model that can identify compounds causing cholestasis by altering bile acid disposition. Human and rat SCH were exposed (24–48 h) to known cholestatic and/or hepatotoxic compounds, in the presence or in the absence of a concentrated mixture of bile acids (BAs). Urea assay was used to assess (compromised) hepatocyte functionality at the end of the incubations. The cholestatic potential of the compounds was expressed by calculating a drug-induced cholestasis index (DICI), reflecting the relative residual urea formation by hepatocytes co-incubated with BAs and test compound as compared to hepatocytes treated with test compound alone. Compounds with clinical reports of cholestasis, including cyclosporin A, troglitazone, chlorpromazine, bosentan, ticlopidine, ritonavir, and midecamycin showed enhanced toxicity in the presence of BAs (DICI ≤ 0.8) for at least one of the tested concentrations. In contrast, the in vitro toxicity of compounds causing hepatotoxicity by other mechanisms (including diclofenac, valproic acid, amiodarone and acetaminophen), remained unchanged in the presence of BAs. A safety margin (SM) for drug-induced cholestasis was calculated as the ratio of lowest in vitro concentration for which was DICI ≤ 0.8, to the reported mean peak therapeutic plasma concentration. SM values obtained in human SCH correlated well with reported % incidence of clinical drug-induced cholestasis, while no correlation was observed in rat SCH. This in vitro model enables early identification of drug candidates causing cholestasis by disturbed BA handling. - Highlights: • Novel in vitro assay to detect drug-induced cholestasis • Rat and human sandwich-cultured hepatocytes (SCH) as in vitro models • Cholestatic compounds sensitize SCH to toxic effects of accumulating bile acids • Drug

  14. Hepatocyte-based in vitro model for assessment of drug-induced cholestasis

    International Nuclear Information System (INIS)

    Chatterjee, Sagnik; Richert, Lysiane; Augustijns, Patrick; Annaert, Pieter

    2014-01-01

    Early detection of drug-induced cholestasis remains a challenge during drug development. We have developed and validated a biorelevant sandwich-cultured hepatocytes- (SCH) based model that can identify compounds causing cholestasis by altering bile acid disposition. Human and rat SCH were exposed (24–48 h) to known cholestatic and/or hepatotoxic compounds, in the presence or in the absence of a concentrated mixture of bile acids (BAs). Urea assay was used to assess (compromised) hepatocyte functionality at the end of the incubations. The cholestatic potential of the compounds was expressed by calculating a drug-induced cholestasis index (DICI), reflecting the relative residual urea formation by hepatocytes co-incubated with BAs and test compound as compared to hepatocytes treated with test compound alone. Compounds with clinical reports of cholestasis, including cyclosporin A, troglitazone, chlorpromazine, bosentan, ticlopidine, ritonavir, and midecamycin showed enhanced toxicity in the presence of BAs (DICI ≤ 0.8) for at least one of the tested concentrations. In contrast, the in vitro toxicity of compounds causing hepatotoxicity by other mechanisms (including diclofenac, valproic acid, amiodarone and acetaminophen), remained unchanged in the presence of BAs. A safety margin (SM) for drug-induced cholestasis was calculated as the ratio of lowest in vitro concentration for which was DICI ≤ 0.8, to the reported mean peak therapeutic plasma concentration. SM values obtained in human SCH correlated well with reported % incidence of clinical drug-induced cholestasis, while no correlation was observed in rat SCH. This in vitro model enables early identification of drug candidates causing cholestasis by disturbed BA handling. - Highlights: • Novel in vitro assay to detect drug-induced cholestasis • Rat and human sandwich-cultured hepatocytes (SCH) as in vitro models • Cholestatic compounds sensitize SCH to toxic effects of accumulating bile acids • Drug

  15. Hepatocyte Aggregate Formation on Chitin-Based Anisotropic Microstructures of Butterfly Wings

    Directory of Open Access Journals (Sweden)

    Abdelrahman Elbaz

    2018-01-01

    Full Text Available Scaffold nanotopography plays the most significant role in the mimicry of the in vivo microenvironment of the hepatocytes. Several attempts have been made to develop methods and substrates suited to growing hepatocytes into aggregates. Functional biomaterials, particularly biodegradable polymers, have been used in several studies aimed to develop improved scaffolds with ordered geometry and nanofibrous architecture for tissue engineering. However, there are still some limitation in their fabrication: it is not cost-efficient, is time-consuming, and exhibits some technological complications. The synthetic scaffolds are usually non-biodegradable and can be non-biocompatible compared to the naturally derived biomaterials. Here, we utilized a simple, cost-effective, and green method with two-step chemical treatment to get more selected hydrophilic butterfly wings from Morpho menelaus, Papilio ulysses telegonus, and Ornithoptera croesus lydius as a chitin-based natural scaffolds to growing hepatocyte aggregates. We established a three-dimensional (3D in vitro model for culture of HepG2 cells and aggregate formation that maintained the hepatocytes function on these natural anisotropic microstructures. Cells cultured on these substrates show higher viability than those cultured on a two-dimensional (2D culture plate. Methylthiazolyldiphenyl-tetrazolium bromide (MTT assay results revealed excellent viability of HepG2 cells on P. u. telegonus wings (fibrous area. The results also demonstrated appropriate cell activity, cell retention, and stable and functional expression in terms of albumin secretion and urea synthesis activity compared to the 2D monolayer culture of hepatocytes on the culture dish surface. With a slightly different degree, the other substrates also shown similar results. We anticipate that these natural anisotropic, biodegradable, and biocompatible substrates can maintain long-term hepatic culture as an in vitro 3D model for potential

  16. Oncostatin M induces upregulation of claudin-2 in rodent hepatocytes coinciding with changes in morphology and function of tight junctions

    International Nuclear Information System (INIS)

    Imamura, Masafumi; Kojima, Takashi; Lan, Mengdong; Son, Seiichi; Murata, Masaki; Osanai, Makoto; Chiba, Hideki; Hirata, Koichi; Sawada, Norimasa

    2007-01-01

    In rodent livers, integral tight junction (TJ) proteins claudin-1, -2, -3, -5 and -14 are detected and play crucial roles in the barrier to keep bile in bile canaculi away from the blood circulation. Claudin-2 shows a lobular gradient increasing from periportal to pericentral hepatocytes, whereas claudin-1 and -3 are expressed in the whole liver lobule. Although claudin-2 expression induces cation-selective channels in tight junctions of epithelial cells, the physiological functions and regulation of claudin-2 in hepatocytes remain unclear. Oncostatin M (OSM) is a multifunctional cytokine implicated in the differentiation of hepatocytes that induces formation of E-cadherin-based adherens junctions in fetal hepatocytes. In this study, we examined whether OSM could induce expression and function of claudin-2 in rodent hepatocytes, immortalized mouse and primary cultured proliferative rat hepatocytes. In the immortalized mouse and primary cultured proliferative rat hepatocytes, treatment with OSM markedly increased mRNA and protein of claudin-2 together with formation of developed networks of TJ strands. The increase of claudin-2 enhanced the paracellular barrier function which depended on molecular size. The increase of claudin-2 expression induced by OSM in rodent hepatocytes was regulated through distinct signaling pathways including PKC. These results suggest that expression of claudin-2 in rodent hepatocytes may play a specific role as controlling the size of paracellular permeability in the barrier to keep bile in bile canaculi

  17. Acrolein cytotoxicity in hepatocytes involves endoplasmic reticulum stress, mitochondrial dysfunction and oxidative stress

    International Nuclear Information System (INIS)

    Mohammad, Mohammad K.; Avila, Diana; Zhang, Jingwen; Barve, Shirish; Arteel, Gavin; McClain, Craig; Joshi-Barve, Swati

    2012-01-01

    Acrolein is a common environmental, food and water pollutant and a major component of cigarette smoke. Also, it is produced endogenously via lipid peroxidation and cellular metabolism of certain amino acids and drugs. Acrolein is cytotoxic to many cell types including hepatocytes; however the mechanisms are not fully understood. We examined the molecular mechanisms underlying acrolein hepatotoxicity in primary human hepatocytes and hepatoma cells. Acrolein, at pathophysiological concentrations, caused a dose-dependent loss of viability of hepatocytes. The death was apoptotic at moderate and necrotic at high concentrations of acrolein. Acrolein exposure rapidly and dramatically decreased intracellular glutathione and overall antioxidant capacity, and activated the stress-signaling MAP-kinases JNK, p42/44 and p38. Our data demonstrate for the first time in human hepatocytes, that acrolein triggered endoplasmic reticulum (ER) stress and activated eIF2α, ATF-3 and -4, and Gadd153/CHOP, resulting in cell death. Notably, the protective/adaptive component of ER stress was not activated, and acrolein failed to up-regulate the protective ER-chaperones, GRP78 and GRP94. Additionally, exposure to acrolein disrupted mitochondrial integrity/function, and led to the release of pro-apoptotic proteins and ATP depletion. Acrolein-induced cell death was attenuated by N-acetyl cysteine, phenyl-butyric acid, and caspase and JNK inhibitors. Our data demonstrate that exposure to acrolein induces a variety of stress responses in hepatocytes, including GSH depletion, oxidative stress, mitochondrial dysfunction and ER stress (without ER-protective responses) which together contribute to acrolein toxicity. Our study defines basic mechanisms underlying liver injury caused by reactive aldehyde pollutants such as acrolein. -- Highlights: ► Human primary hepatocytes and cultured cell lines are used. ► Multiple cell death signaling pathways are activated by acrolein. ► Novel finding of

  18. Acrolein cytotoxicity in hepatocytes involves endoplasmic reticulum stress, mitochondrial dysfunction and oxidative stress

    Energy Technology Data Exchange (ETDEWEB)

    Mohammad, Mohammad K. [Department of Medicine, University of Louisville (United States); Alcohol Research Center, University of Louisville (United States); Avila, Diana [Department of Medicine, University of Louisville (United States); Department of Pharmacology and Toxicology, University of Louisville (United States); Alcohol Research Center, University of Louisville (United States); Zhang, Jingwen [Department of Medicine, University of Louisville (United States); Alcohol Research Center, University of Louisville (United States); Barve, Shirish [Department of Medicine, University of Louisville (United States); Department of Pharmacology and Toxicology, University of Louisville (United States); Alcohol Research Center, University of Louisville (United States); Arteel, Gavin [Department of Pharmacology and Toxicology, University of Louisville (United States); Alcohol Research Center, University of Louisville (United States); McClain, Craig [Department of Medicine, University of Louisville (United States); Department of Pharmacology and Toxicology, University of Louisville (United States); Alcohol Research Center, University of Louisville (United States); Robley Rex VAMC, Louisville, KY (United States); Joshi-Barve, Swati, E-mail: s0josh01@louisville.edu [Department of Medicine, University of Louisville (United States); Department of Pharmacology and Toxicology, University of Louisville (United States); Alcohol Research Center, University of Louisville (United States)

    2012-11-15

    Acrolein is a common environmental, food and water pollutant and a major component of cigarette smoke. Also, it is produced endogenously via lipid peroxidation and cellular metabolism of certain amino acids and drugs. Acrolein is cytotoxic to many cell types including hepatocytes; however the mechanisms are not fully understood. We examined the molecular mechanisms underlying acrolein hepatotoxicity in primary human hepatocytes and hepatoma cells. Acrolein, at pathophysiological concentrations, caused a dose-dependent loss of viability of hepatocytes. The death was apoptotic at moderate and necrotic at high concentrations of acrolein. Acrolein exposure rapidly and dramatically decreased intracellular glutathione and overall antioxidant capacity, and activated the stress-signaling MAP-kinases JNK, p42/44 and p38. Our data demonstrate for the first time in human hepatocytes, that acrolein triggered endoplasmic reticulum (ER) stress and activated eIF2α, ATF-3 and -4, and Gadd153/CHOP, resulting in cell death. Notably, the protective/adaptive component of ER stress was not activated, and acrolein failed to up-regulate the protective ER-chaperones, GRP78 and GRP94. Additionally, exposure to acrolein disrupted mitochondrial integrity/function, and led to the release of pro-apoptotic proteins and ATP depletion. Acrolein-induced cell death was attenuated by N-acetyl cysteine, phenyl-butyric acid, and caspase and JNK inhibitors. Our data demonstrate that exposure to acrolein induces a variety of stress responses in hepatocytes, including GSH depletion, oxidative stress, mitochondrial dysfunction and ER stress (without ER-protective responses) which together contribute to acrolein toxicity. Our study defines basic mechanisms underlying liver injury caused by reactive aldehyde pollutants such as acrolein. -- Highlights: ► Human primary hepatocytes and cultured cell lines are used. ► Multiple cell death signaling pathways are activated by acrolein. ► Novel finding of

  19. Serum Hepatocyte Growth Factor as A Non-Invasive Marker For Evaluation of Hepatocellular Carcinoma

    International Nuclear Information System (INIS)

    Abdelgawad, M.R.; Wahba, M.A.

    2012-01-01

    The change and the prognostic value of serum hepatocyte growth factor and AFP level in patients with cirrhosis and/or primary liver cancer (HCC) were investigated. The level of serum hepatocyte growth factor was determined by using enzyme-linked immunosorbent assay, and AFP was determined by using radioimmunoassay in 29 patients with cirrhosis. Twenty five patients with primary liver cancer (13 patients without nodular cirrhosis and 12 patients with nodular cirrhosis) were categorized according to tumour size (≤ or >5 cm) and the level of AFP (≤ or > 200 ng/dl). The correlation between serum AFP and hepatocyte growth factor were significantly increased (P 0.05). Serum AFP can significantly discriminate between all studied groups (P 0.001) except for the comparison between control and cirrhosis (P>0.05), and also between HCC and HCC without nodular cirrhosis and HCC with cirrhosis (P>0.05). Serum HGF and AFP levels were positively affected by tumour size and nodular cirrhosis (P<0.001). Also, serum HGF level was highly affected by the levels of serum AFP in HCC patients. Non-significant correlation was observed between serum hepatocyte growth factor and AFP in control, cirrhosis, cirrhosis and HCC patients with AFP ? 200 ng/dl. It could be concluded that the over expressions of the hepatocyte growth factor and AFP may indicate an adverse prognosis for patients with cirrhosis and/or liver cancer. The sustained high level of serum hepatocyte growth factor in cirrhosis and/or HCC could be considered a factor related to early tumour diagnosis, so, serum HGF level may be used as a non-invasive marker in diagnosis and prognosis of liver malignancy. However, further studies are highly recommended to evaluate the role of HGF or its constituents in diagnosis and/or therapy in the future in a larger cohort of patients with different stages of liver malignancy

  20. Hepatocyte growth factor is crucial for development of the carapace in turtles.

    Science.gov (United States)

    Kawashima-Ohya, Yoshie; Narita, Yuichi; Nagashima, Hiroshi; Usuda, Ryo; Kuratani, Shigeru

    2011-01-01

    Turtles are characterized by their shell, composed of a dorsal carapace and a ventral plastron. The carapace first appears as the turtle-specific carapacial ridge (CR) on the lateral aspect of the embryonic flank. Accompanying the acquisition of the shell, unlike in other amniotes, hypaxial muscles in turtle embryos appear as thin threads of fibrous tissue. To understand carapacial evolution from the perspective of muscle development, we compared the development of the muscle plate, the anlage of hypaxial muscles, between the Chinese soft-shelled turtle, Pelodiscus sinensis, and chicken embryos. We found that the ventrolateral lip (VLL) of the thoracic dermomyotome of P. sinensis delaminates early and produces sparse muscle plate in the lateral body wall. Expression patterns of the regulatory genes for myotome differentiation, such as Myf5, myogenin, Pax3, and Pax7 have been conserved among amniotes, including turtles. However, in P. sinensis embryos, the gene hepatocyte growth factor (HGF), encoding a regulatory factor for delamination of the dermomyotomal VLL, was uniquely expressed in sclerotome and the lateral body wall at the interlimb level. Implantation of COS-7 cells expressing a HGF antagonist into the turtle embryo inhibited CR formation. We conclude that the de novo expression of HGF in the turtle mesoderm would have played an innovative role resulting in the acquisition of the turtle-specific body plan. © 2011 Wiley Periodicals, Inc.

  1. Computational Topology Based Quantification Of Hepatocytes Nuclei In Lipopolysaccharide-Induced Liver Injury In Mice

    Directory of Open Access Journals (Sweden)

    Rodrigo Rojas Moraleda

    2016-06-01

    The computational topology approach proposed successfully detected hepatocyte cells under several natural variations. We evaluated on a per-pixel basis how the segmentation performs on: i all nuclei in the images, ii big round nuclei considered belonging to hepatocytes cells (accuracy 87.2%, recall 80.3%, and iii nuclei regarded to non-parenchymal cells.  

  2. In vitro differentiation and maturation of mouse embryonic stem cells into hepatocytes

    International Nuclear Information System (INIS)

    Ishii, Takamichi; Yasuchika, Kentaro; Fujii, Hideaki; Hoppo, Toshitaka; Baba, Shinji; Naito, Masato; Machimoto, Takafumi; Kamo, Naoko; Suemori, Hirofumi; Nakatsuji, Norio; Ikai, Iwao

    2005-01-01

    It is difficult to induce the maturation of embryonic stem (ES) cells into hepatocytes in vitro. We previously reported that Thy1-positive mesenchymal cells derived from the mouse fetal liver promote the maturation of hepatic progenitor cells. Here, we isolated alpha-fetoprotein (AFP)-producing cells from mouse ES cells for subsequent differentiation into hepatocytes in vitro by coculture with Thy1-positive cells. ES cells expressing green fluorescent protein (GFP) under the control of an AFP promoter were cultured under serum- and feeder layer-free culture conditions. The proportion of GFP-positive cells plateaued at 41.6 ± 12.2% (means ± SD) by day 7. GFP-positive cells, isolated by flow cytometry, were cultured in the presence or absence of Thy1-positive cells as a feeder layer. Isolated GFP-positive cells were stained for AFP, Foxa2, and albumin. The expression of mRNAs encoding tyrosine amino transferase, tryptophan 2,3-dioxygenase, and glucose-6-phosphatase were only detected following coculture with Thy1-positive cells. Following coculture with Thy1-positive cells, the isolated cells produced and stored glycogen. Ammonia clearance activity was also enhanced following coculture. Electron microscopic analysis indicated that the cocultured cells exhibited the morphologic features of mature hepatocytes. In conclusion, coculture with Thy1-positive cells in vitro induced the maturation of AFP-producing cells isolated from ES cell cultures into hepatocytes

  3. Purification, characterisation and protective effects of polysaccharides from alfalfa on hepatocytes.

    Science.gov (United States)

    Wang, Shaopu; Dong, Xiaofang; Ma, Hao; Cui, Yaoming; Tong, Jianming

    2014-11-04

    The objective of this study was to determine the preliminary characteristics and protective effects of alfalfa polysaccharides (APS) on hepatocytes in vitro. The crude APS was purified by DEAE-cellulose and Sephadex G-100 chromatography, resulting in the four purified fractions: APS-1, APS-2, APS-3 and APS-4. The results indicated that APS-3 had higher carbohydrate and uronic acid contents and that APS-4 had a more complicated monosaccharide composition compared to the other purified fractions. The average molecular weights of APS-1, APS-2, APS-3 and APS-4 were 48,536, 6,221, 66,559 and 13,076 Da, respectively. Furthermore, APS (crude and its purified fractions) restored the activities of antioxidant enzymes and increased the total antioxidant capacity of hepatocytes subjected to H2O2-induced oxidative stress. Furthermore, APS treatment counteracted the increases in lactic dehydrogenase and malonaldehyde in the culture supernatant. These results clearly demonstrate that APS possesses a protective effect against oxidative injury in hepatocytes. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. The regulation of cytoskeletal and liver-specific gene expression during liver regeneration and primary hepatocyte culture

    International Nuclear Information System (INIS)

    Robinson, G.S.

    1989-01-01

    The focus of this dissertation is to determine what role(s) the extracellular matrix and expression of certain cytoskeletal genes play in the regulation of hepatocyte growth and the maintenance of a differential state. The expression of several cytoskeletal and liver-specific genes was examined during liver regeneration and in hepatocyte cultures maintained in a hormonally-defined, serum-free medium and plated on two different matrices: rat tail collagen and the EHS matrix. During liver regeneration and in hepatocytes cultured on rat tail collagen, there was a dramatic increase in tubulin mRNA levels coincident with but not linked to DNA synthesis. The message levels for other cytoskeletal genes similarly increased, while a decrease was observed in the mRNA levels of the liver-specific genes, serum albumin and alpha 1 inhibitor III. Hepatocytes cultured on the EHS matrix resulted in the maintenance of low levels of cytoskeletal gene expression and high levels of liver-specific gene expression, similar to that observed in the normal liver. Results from subcellar fractionation and two-dimensional gel electrophoresis of 35 S-labelled proteins paralleled the results seen at the mRNA level. Preliminary work suggests that microtubule organization may play a role in the expression of the liver-specific genes which encode secreted proteins. These studies, which compare hepatocytes cultured on collagen or the EHS matrix gel, reveal that both cell-cell and cell-matrix interactions play a major role in the maintenance of the differential phenotype in hepatocytes

  5. 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.

  6. Nor-ursodeoxycholic acid reverses hepatocyte-specific nemo-dependent steatohepatitis.

    Science.gov (United States)

    Beraza, Naiara; Ofner-Ziegenfuss, Lisa; Ehedego, Haksier; Boekschoten, Mark; Bischoff, Stephan C; Mueller, Michael; Trauner, Michael; Trautwein, Christian

    2011-03-01

    Hepatocyte-specific NEMO/NF-κB deleted mice (NEMO(Δhepa)) develop spontaneous non-alcoholic steatohepatitis (NASH). Free fatty acids and bile acids promote DR5 expression. TRAIL/NK cell-mediated activation of TRAIL-R2/DR5 plays an important role during acute injury in NEMO(Δhepa) mice. To inhibit the progression of NASH in the absence of hepatocyte-NEMO/NF-kB signaling. NEMOf/f and NEMO(Δhepa) mice were fed with a low-fat diet, and with two anticholestatic diets; UDCA and NorUDCA. The impact of these treatments on the progression of NASH was evaluated. We show that high expression of DR5 in livers from NEMO(Δhepa) mice is accompanied by an abundant presence of bile acids (BAs), misregulation of BA transporters and significant alteration of lipid metabolism-related genes. Additionally, mice lacking NEMO in hepatocytes spontaneously showed ductular response at young age. Unexpectedly, feeding of NEMO(Δhepa) mice with low-fat diet failed to improve chronic liver injury. Conversely, anti-cholestatic treatment with nor-ursodeoxycholic acid (NorUDCA), but not with ursodeoxycholic acid (UDCA), led to a significant attenuation of liver damage in NEMO(Δhepa) mice. The strong therapeutic effect of NorUDCA relied on a significant downregulation of LXR-dependent lipogenesis and the normalisation of BA metabolism through mechanisms involving cross-talk between Cyp7a1 and SHP. This was associated with the significant improvement of liver histology, NEMO(Δhepa)/NorUDCA-treated mice showed lower apoptosis and reduced CyclinD1 expression, indicating attenuation of the compensatory proliferative response to hepatocellular damage. Finally, fibrosis and ductular reaction markers were significantly reduced in NorUDCA-treated NEMO(Δhepa) mice. Overall, our work demonstrates the contribution of bile acids metabolism to the progression of NASH in the absence of hepatocyte-NF-kB through mechanisms involving DR5-apoptosis, inflammation and fibrosis. Our work suggests a potential

  7. Acrolein cytotoxicity in hepatocytes involves endoplasmic reticulum stress, mitochondrial dysfunction and oxidative stress

    OpenAIRE

    Mohammad, Mohammad K; Avila, Diana; Zhang, Jingwen; Barve, Shirish; Arteel, Gavin; McClain, Craig; Joshi-Barve, Swati

    2012-01-01

    Acrolein is a common environmental, food and water pollutant and a major component of cigarette smoke. Also, it is produced endogenously via lipid peroxidation and cellular metabolism of certain amino acids and drugs. Acrolein is cytotoxic to many cell types including hepatocytes; however the mechanisms are not fully understood. We examined the molecular mechanisms underlying acrolein hepatotoxicity in primary human hepatocytes and hepatoma cells. Acrolein, at pathophysiological concentration...

  8. [Mortality among able-bodied population in industrial cities in accordance with specific enterprise forming a company city].

    Science.gov (United States)

    Tikhonova, G I; Gorchakova, T Iu; Churanova, A N

    2013-01-01

    The article covers comparative analysis of mortality causes and levels among male able-bodied population in small and medium industrial cities of Murmansk region in accordance with specific enterprise forming a company city. Findings are that, if compared to Murmansk having no enterprise forming a company, other industrial cities in the region, situated in the same climate area, demonstrated higher levels of mortality among the male able-bodied population with the death causes associated etiologically to occupational hazards on the enterprises forming a company city.

  9. Acquisition of lipid metabolic capability in hepatocyte-like cells directly induced from mouse fibroblasts

    Directory of Open Access Journals (Sweden)

    Shizuka eMiura

    2014-08-01

    Full Text Available Recently, the numbers of patients with non-alcoholic fatty liver disease (NAFLD and non-alcoholic steatohepatitis (NASH have increased worldwide. NAFLD and NASH are known as risk factors for liver cirrhosis and hepatocellular carcinoma. Because many factors can promote the progression of NAFLD and NASH, the treatment of these patients involves various strategies. Thus, it is desired that drugs for patients with NAFLD and NASH should be developed more easily and rapidly using cultures of primary hepatocytes. However, it is difficult to use hepatocytes as a tool for drug screening, because these cells cannot be functionally maintained in culture. Thus, in this study, we sought to examine whether induced hepatocyte-like (iHep cells, which were directly induced from mouse dermal fibroblasts by infection with a retrovirus expressing Hnf4α and Foxa3, possess the potential for lipid metabolism, similar to hepatocytes. Our data showed that iHep cells were capable of synthesizing lipids from a cis-unsaturated fatty acid, a trans-unsaturated fatty acid, and a saturated fatty acid, accumulating the synthesized lipids in cellular vesicles, and secreting the lipids into the culture medium. Moreover, the lipid synthesis in iHep cells was significantly inhibited in cultures with lipid metabolism improvers. These results demonstrate that iHep cells could be useful not only for screening of drugs for patients with NAFLD and NASH, but also for elucidation of the mechanisms underlying hereditary lipid metabolism disorders, as an alternative to hepatocytes.

  10. Generation, characterization and potential therapeutic applications of mature and functional hepatocytes from stem cells.

    Science.gov (United States)

    Zhang, Zhenzhen; Liu, Jianfang; Liu, Yang; Li, Zheng; Gao, Wei-Qiang; He, Zuping

    2013-02-01

    Liver cancer is the sixth most common tumor in the world and the majority of patients with this disease usually die within 1 year. The effective treatment for end-stage liver disease (also known as liver failure), including liver cancer or cirrhosis, is liver transplantation. However, there is a severe shortage of liver donors worldwide, which is the major handicap for the treatment of patients with liver failure. Scarcity of liver donors underscores the urgent need of using stem cell therapy to the end-stage liver disease. Notably, hepatocytes have recently been generated from hepatic and extra-hepatic stem cells. We have obtained mature and functional hepatocytes from rat hepatic stem cells. Here, we review the advancements on hepatic differentiation from various stem cells, including hepatic stem cells, embryonic stem cells, the induced pluripotent stem cells, hematopoietic stem cells, mesenchymal stem cells, and probably spermatogonial stem cells. The advantages, disadvantages, and concerns on differentiation of these stem cells into hepatic cells are highlighted. We further address the methodologies, phenotypes, and functional characterization on the differentiation of numerous stem cells into hepatic cells. Differentiation of stem cells into mature and functional hepatocytes, especially from an extra-hepatic stem cell source, would circumvent the scarcity of liver donors and human hepatocytes, and most importantly it would offer an ideal and promising source of hepatocytes for cell therapy and tissue engineering in treating liver disease. Copyright © 2012 Wiley Periodicals, Inc.

  11. Hepatitis B virus evasion from cGAS sensing in human hepatocytes.

    Science.gov (United States)

    Verrier, Eloi R; Yim, Seung-Ae; Heydmann, Laura; El Saghire, Houssein; Bach, Charlotte; Turon-Lagot, Vincent; Mailly, Laurent; Durand, Sarah C; Lucifora, Julie; Durantel, David; Pessaux, Patrick; Manel, Nicolas; Hirsch, Ivan; Zeisel, Mirjam B; Pochet, Nathalie; Schuster, Catherine; Baumert, Thomas F

    2018-04-20

    Chronic hepatitis B virus (HBV) infection is a major cause of chronic liver disease and cancer worldwide. The mechanisms of viral genome sensing and the evasion of innate immune responses by HBV infection are still poorly understood. Recently, the cyclic GMP-AMP synthase (cGAS) was identified as a DNA sensor. In this study, we aimed to investigate the functional role of cGAS in sensing of HBV infection and elucidate the mechanisms of viral evasion. We performed functional studies including loss- and gain-of-function experiments combined with cGAS effector gene expression profiling in an infectious cell culture model, primary human hepatocytes and HBV-infected human liver chimeric mice. Here we show that cGAS is expressed in the human liver, primary human hepatocytes and human liver chimeric mice. While naked relaxed-circular HBV DNA is sensed in a cGAS-dependent manner in hepatoma cell lines and primary human hepatocytes, host cell recognition of viral nucleic acids is abolished during HBV infection, suggesting escape from sensing, likely during packaging of the genome into the viral capsid. While the hepatocyte cGAS pathway is functionally active, as shown by reduction of viral cccDNA levels in gain-of-function studies, HBV infection suppressed cGAS expression and function in cell culture models and humanized mice. HBV exploits multiple strategies to evade sensing and antiviral activity of cGAS and its effector pathways. This article is protected by copyright. All rights reserved. © 2018 by the American Association for the Study of Liver Diseases.

  12. Hepatocytes in the development of liver support systems

    NARCIS (Netherlands)

    I.H.M. Borel Rinkes (Inne)

    1993-01-01

    textabstractThis thesis focuses on the development of alternative strategies in the treatment of patients with acute fulminant hepatic failure and inborn errors of metabolism, using hepatocytes as the basis of liver support. When compared with transplantation of the liver as an organ, the

  13. Palm kernel cake extract exerts hepatoprotective activity in heat-induced oxidative stress in chicken hepatocytes.

    Science.gov (United States)

    Oskoueian, Ehsan; Abdullah, Norhani; Idrus, Zulkifli; Ebrahimi, Mahdi; Goh, Yong Meng; Shakeri, Majid; Oskoueian, Armin

    2014-10-02

    Palm kernel cake (PKC), the most abundant by-product of oil palm industry is believed to contain bioactive compounds with hepatoprotective potential. These compounds may serve as hepatoprotective agents which could help the poultry industry to alleviate adverse effects of heat stress on liver function in chickens. This study was performed to evaluate the hepatoprotective potential of PKC extract in heat-induced oxidative stress in chicken hepatocytes. The nature of the active metabolites and elucidation of the possible mechanism involved were also investigated. The PKC extract possessed free radical scavenging activity with values significantly (p < 0.05) lower than silymarin as the reference antioxidant. Heat-induced oxidative stress in chicken hepatocyte impaired the total protein, lipid peroxidation and antioxidant enzymes activity significantly (p < 0.05). Treatment of heat-induced hepatocytes with PKC extract (125 μg/ml) and silymarin as positive control increased these values significantly (p < 0.05). The real time PCR and western blot analyses revealed the significant (p < 0.05) up-regulation of oxidative stress biomarkers including TNF-like, IFN-γ and IL-1β genes; NF-κB, COX-2, iNOS and Hsp70 proteins expression upon heat stress in chicken hepatocytes. The PKC extract and silymarin were able to alleviate the expression of all of these biomarkers in heat-induced chicken hepatocytes. The gas chromatography-mass spectrometry analysis of PKC extract showed the presence of fatty acids, phenolic compounds, sugar derivatives and other organic compounds such as furfural which could be responsible for the observed hepatoprotective activity. Palm kernel cake extract could be a potential agent to protect hepatocytes function under heat induced oxidative stress.

  14. Adenoviral-mediated correction of methylmalonyl-CoA mutase deficiency in murine fibroblasts and human hepatocytes

    Directory of Open Access Journals (Sweden)

    Korson Mark

    2007-04-01

    Full Text Available Abstract Background Methylmalonic acidemia (MMA, a common organic aciduria, is caused by deficiency of the mitochondrial localized, 5'deoxyadenosylcobalamin dependent enzyme, methylmalonyl-CoA mutase (MUT. Liver transplantation in the absence of gross hepatic dysfunction provides supportive therapy and metabolic stability in severely affected patients, which invites the concept of using cell and gene delivery as future treatments for this condition. Methods To assess the effectiveness of gene delivery to restore the defective metabolism in this disorder, adenoviral correction experiments were performed using murine Mut embryonic fibroblasts and primary human methylmalonyl-CoA mutase deficient hepatocytes derived from a patient who harbored two early truncating mutations, E224X and R228X, in the MUT gene. Enzymatic and expression studies were used to assess the extent of functional correction. Results Primary hepatocytes, isolated from the native liver after removal subsequent to a combined liver-kidney transplantation procedure, or Mut murine fibroblasts were infected with a second generation recombinant adenoviral vector that expressed the murine methylmalonyl-CoA mutase as well as eGFP from distinct promoters. After transduction, [1-14C] propionate macromolecular incorporation studies and Western analysis demonstrated complete correction of the enzymatic defect in both cell types. Viral reconstitution of enzymatic expression in the human methylmalonyl-CoA mutase deficient hepatocytes exceeded that seen in fibroblasts or control hepatocytes. Conclusion These experiments provide proof of principle for viral correction in methylmalonic acidemia and suggest that hepatocyte-directed gene delivery will be an effective therapeutic treatment strategy in both murine models and in human patients. Primary hepatocytes from a liver that was unsuitable for transplantation provided an important resource for these studies.

  15. High-Affinity Low-Capacity and Low-Affinity High-Capacity N-Acetyl-2-Aminofluorene (AAF) Macromolecular Binding Sites Are Revealed During the Growth Cycle of Adult Rat Hepatocytes in Primary Culture.

    Science.gov (United States)

    Koch, Katherine S; Moran, Tom; Shier, W Thomas; Leffert, Hyam L

    2018-05-01

    Long-term cultures of primary adult rat hepatocytes were used to study the effects of N-acetyl-2-aminofluorene (AAF) on hepatocyte proliferation during the growth cycle; on the initiation of hepatocyte DNA synthesis in quiescent cultures; and, on hepatocyte DNA replication following the initiation of DNA synthesis. Scatchard analyses were used to identify the pharmacologic properties of radiolabeled AAF metabolite binding to hepatocyte macromolecules. Two classes of growth cycle-dependent AAF metabolite binding sites-a high-affinity low-capacity site (designated Site I) and a low-affinity high-capacity site (designated Site II)-associated with two spatially distinct classes of macromolecular targets, were revealed. Based upon radiolabeled AAF metabolite binding to purified hepatocyte genomic DNA or to DNA, RNA, proteins, and lipids from isolated nuclei, Site IDAY 4 targets (KD[APPARENT] ≈ 2-4×10-6 M and BMAX[APPARENT] ≈ 6 pmol/106 cells/24 h) were consistent with genomic DNA; and with AAF metabolized by a nuclear cytochrome P450. Based upon radiolabeled AAF binding to total cellular lysates, Site IIDAY 4 targets (KD[APPARENT] ≈ 1.5×10-3 M and BMAX[APPARENT] ≈ 350 pmol/106 cells/24 h) were consistent with cytoplasmic proteins; and with AAF metabolized by cytoplasmic cytochrome P450s. DNA synthesis was not inhibited by concentrations of AAF that saturated DNA binding in the neighborhood of the Site I KD. Instead, hepatocyte DNA synthesis inhibition required higher concentrations of AAF approaching the Site II KD. These observations raise the possibility that carcinogenic DNA adducts derived from AAF metabolites form below concentrations of AAF that inhibit replicative and repair DNA synthesis.

  16. Effect of UV-B (302 nm) irradiation on isolated rat hepatocytes

    International Nuclear Information System (INIS)

    Lahiri, S.; Habibullah, C.M.; Ayesha, Q.; Khan, A.A.; Srinivas, V.K.; Naithani, R.

    1995-01-01

    The present study aimed to evaluate the effect of UV-B irradiation on the functional integrity, and the metabolic and detoxifying capacity of isolated rat hepatocytes. Isolated rat hepatocytes were irradiated in various doses (400 Jm -2 , 600 Jm -2 , 800 Jm -2 and 1000 Jm -2 ). The cells were assayed for total lactate dehydrogenase, Na + -K + -ATPase, ATPase, ornithine carbamyltransferase activity (OCT) and urea production capacity. Lactate dehydrogenase and Na + -K + -ATPase activity were significantly decreased in all four irradiated groups (P<0.001), whereas viability, OCT and urea production capacity showed no alterations. (au) 22 refs

  17. Acrolein cytotoxicity in hepatocytes involves endoplasmic reticulum stress, mitochondrial dysfunction and oxidative stress

    Science.gov (United States)

    Mohammad, Mohammad K; Avila, Diana; Zhang, Jingwen; Barve, Shirish; Arteel, Gavin; McClain, Craig; Joshi-Barve, Swati

    2012-01-01

    Acrolein is a common environmental, food and water pollutant and a major component of cigarette smoke. Also, it is produced endogenously via lipid peroxidation and cellular metabolism of certain amino acids and drugs. Acrolein is cytotoxic to many cell types including hepatocytes; however the mechanisms are not fully understood. We examined the molecular mechanisms underlying acrolein hepatotoxicity in primary human hepatocytes and hepatoma cells. Acrolein, at pathophysiological concentrations, caused a dose-dependent loss of viability of hepatocytes. The death was apoptotic at moderate and necrotic at high concentrations of acrolein. Acrolein exposure rapidly and dramatically decreased intracellular glutathione and overall antioxidant capacity, and activated the stress-signaling MAP-kinases JNK, p42/44 and p38. Our data demonstrate for the first time in human hepatocytes, that acrolein triggered endoplasmic reticulum (ER) stress and activated eIF2α, ATF-3 and -4, and Gadd153/CHOP, resulting in cell death. Notably, the protective/adaptive component of ER stress was not activated, and acrolein failed to up-regulate the protective ER-chaperones, GRP78 and GRP94. Additionally, exposure to acrolein disrupted mitochondrial integrity/function, and led to the release of pro-apoptotic proteins and ATP depletion. Acrolein-induced cell death was attenuated by N-acetyl cysteine, phenyl-butyric acid, and caspase and JNK inhibitors. Our data demonstrate that exposure to acrolein induces a variety of stress responses in hepatocytes, including GSH depletion, oxidative stress, mitochondrial dysfunction and ER stress (without ER-protective responses) which together contribute to acrolein toxicity. Our study defines basic mechanisms underlying liver injury caused by reactive aldehyde pollutants such as acrolein. PMID:23026831

  18. Glycogen content in hepatocytes is related with their size in normal rat liver but not in cirrhotic one.

    Science.gov (United States)

    Bezborodkina, Natalia N; Chestnova, Anna Yu; Vorobev, Mikhail L; Kudryavtsev, Boris N

    2016-04-01

    Hepatocytes differ from one another by the degree of the ploidy, size, position in the liver lobule, and level of the DNA-synthetic processes. It is believed, that the cell size exerts substantial influence on the metabolism of the hepatocytes and the glycogen content in them. The aim of the present study was to test this hypothesis. Dry weight of hepatocytes, their ploidy and glycogen content were determined in the normal and the cirrhotic rat liver. Liver cirrhosis in rats was produced by chronic inhalation of CCl4 vapours in the course of 6 months. A combined cytophotometric method was used. Dry weight of the cell, its glycogen and DNA content were successively measured on a mapped preparation. Hepatocytes of each ploidy class in the normal and the cirrhotic rat liver accumulated glycogen at the same rate. In the normal liver, there was a distinct correlation between the size of hepatocytes and glycogen content in them. This correlation was observed in each ploidy class, and was especially pronounced in the class of mononucleate tetraploid hepatocytes. In the cirrhotic liver, there was no correlation between the size of the cells and their glycogen content. The impairment of liver lobular structure probably explains the observed lack of correlation between hepatocyte size and their glycogen content in the cirrhotic liver. © 2016 International Society for Advancement of Cytometry. © 2016 International Society for Advancement of Cytometry.

  19. Interleukin 6 regulates metallothionein gene expression and zinc metabolism in hepatocyte monolayer cultures

    International Nuclear Information System (INIS)

    Schroeder, J.J.; Cousins, R.J.

    1990-01-01

    Attention has focused on the cytokine interleukin 6 (IL-6) as a major mediator of acute-phase protein synthesis in hepatocytes in response to infection and tissue injury. The authors have evaluated the effects of IL-6 and IL-1α as well as extracellular zinc and glucocorticoid hormone on metal-lothionein gene expression and cellular zinc accumulation in rat hepatocyte monolayer cultures. Further, they have evaluated the teleological basis for cytokine mediation by examining cyto-protection from CCl 4 -induced damage. Incubation of hepatocytes with IL-6 led to concentration-dependent and time-dependent increases in metallothionein-1 and -2 mRNA and metallothionein protein. The level of each was increased within 3 hr after the addition of IL-6 at 10 ng/ml. Maximal increases the metallothionein mRNA and metallothionein protein were achieved after 12 hr and 36 hr, respectively. Concomitant with the up-regulation of metallothionein gene expression, IL-6 also increased cellular zinc. Responses to IL-6 required the synthetic glucocorticoid hormone dexamethasone and were optimized by increased extracellular zinc. Thus, IL-6 is a major cytokine mediator of metallothionein gene expression and zinc metabolism in hepatocytes and provides cytoprotection from CCl 4 -induced hepatotoxicity via a mode consistent with dependence upon increased cellular metallothionein synthesis and zinc accumulation

  20. Insulin internalization in isolated rat hepatocytes

    International Nuclear Information System (INIS)

    Galan, J.; Trankina, M.; Noel, R.; Ward, W.

    1990-01-01

    This project was designed to determine whether neomycin, an aminoglycoside antibiotic, has a significant effect upon the pathways of ligand endocytosis in isolated rat hepatocytes. The pathways studied include receptor-mediated endocytosis and fluid-phase endocytosis. Neomycin causes a dose-dependent acceleration of 125 I-insulin internalization. Since fluid-phase endocytosis can also be a significant factor in 125 I-insulin internalization, lucifer yellow (LY), a marker for fluid-phase endocytosis, was incorporated into an assay similar to the 125 I-insulin internalization procedure. In the presence of 5 mM neomycin, a significant increase in LY uptake was evident at 0.2 and 0.4 mg/ml of LY. At 0.8 mg/ml, a decrease in LY uptake was observed. The increased rate of 125 I-insulin internalization in the presence of neomycin was intriguing. Since one action of neomycin is to inhibit phosphoinositidase C, it suggests that the phosphotidylinositol cycle may be involved in ligand internalization by hepatocytes. At low insulin concentrations, receptor-mediated uptake predominates. Fluid-phase uptake can become an important uptake route as insulin concentrations are increased. Since neomycin stimulates fluid-phase endocytosis, it must also be taken into account when measuring ligand internalization

  1. A Nonhuman Primate Model of Human Radiation-Induced Venocclusive Liver Disease and Hepatocyte Injury

    Energy Technology Data Exchange (ETDEWEB)

    Yannam, Govardhana Rao [Department of Surgery, University of Nebraska Medical Center, Omaha, Nebraska (United States); Han, Bing [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Department of Hepatobiliary Surgery, First Affiliated Hospital of Xi' an Jiaotong University, Xi' an, Shaanxi (China); Setoyama, Kentaro [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Yamamoto, Toshiyuki [Department of Surgery, University of Nebraska Medical Center, Omaha, Nebraska (United States); Ito, Ryotaro; Brooks, Jenna M. [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Guzman-Lepe, Jorge [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Department of Pathology, Children' s Hospital of Pittsburgh, Pittsburgh, Pennsylvania (United States); Galambos, Csaba [Department of Pathology, Children' s Hospital of Pittsburgh, Pittsburgh, Pennsylvania (United States); Fong, Jason V. [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Deutsch, Melvin; Quader, Mubina A. [Department of Radiation Oncology, Children' s Hospital of Pittsburgh, Pittsburgh, Pennsylvania (United States); Yamanouchi, Kosho [Department of Radiation Oncology, Albert Einstein College of Medicine, Bronx, New York (United States); Marion Bessin Liver Research Center, Albert Einstein College of Medicine, Bronx, New York (United States); Kabarriti, Rafi; Mehta, Keyur [Department of Radiation Oncology, Albert Einstein College of Medicine, Bronx, New York (United States); Soto-Gutierrez, Alejandro [Department of Pathology, Children' s Hospital of Pittsburgh, Pittsburgh, Pennsylvania (United States); McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); and others

    2014-02-01

    Background: Human liver has an unusual sensitivity to radiation that limits its use in cancer therapy or in preconditioning for hepatocyte transplantation. Because the characteristic veno-occlusive lesions of radiation-induced liver disease do not occur in rodents, there has been no experimental model to investigate the limits of safe radiation therapy or explore the pathogenesis of hepatic veno-occlusive disease. Methods and Materials: We performed a dose-escalation study in a primate, the cynomolgus monkey, using hypofractionated stereotactic body radiotherapy in 13 animals. Results: At doses ≥40 Gy, animals developed a systemic syndrome resembling human radiation-induced liver disease, consisting of decreased albumin, elevated alkaline phosphatase, loss of appetite, ascites, and normal bilirubin. Higher radiation doses were lethal, causing severe disease that required euthanasia approximately 10 weeks after radiation. Even at lower doses in which radiation-induced liver disease was mild or nonexistent, latent and significant injury to hepatocytes was demonstrated by asialoglycoprotein-mediated functional imaging. These monkeys developed hepatic failure with encephalopathy when they received parenteral nutrition containing high concentrations of glucose. Histologically, livers showed central obstruction via an unusual intimal swelling that progressed to central fibrosis. Conclusions: The cynomolgus monkey, as the first animal model of human veno-occlusive radiation-induced liver disease, provides a resource for characterizing the early changes and pathogenesis of venocclusion, for establishing nonlethal therapeutic dosages, and for examining experimental therapies to minimize radiation injury.

  2. A Nonhuman Primate Model of Human Radiation-Induced Venocclusive Liver Disease and Hepatocyte Injury

    International Nuclear Information System (INIS)

    Yannam, Govardhana Rao; Han, Bing; Setoyama, Kentaro; Yamamoto, Toshiyuki; Ito, Ryotaro; Brooks, Jenna M.; Guzman-Lepe, Jorge; Galambos, Csaba; Fong, Jason V.; Deutsch, Melvin; Quader, Mubina A.; Yamanouchi, Kosho; Kabarriti, Rafi; Mehta, Keyur; Soto-Gutierrez, Alejandro

    2014-01-01

    Background: Human liver has an unusual sensitivity to radiation that limits its use in cancer therapy or in preconditioning for hepatocyte transplantation. Because the characteristic veno-occlusive lesions of radiation-induced liver disease do not occur in rodents, there has been no experimental model to investigate the limits of safe radiation therapy or explore the pathogenesis of hepatic veno-occlusive disease. Methods and Materials: We performed a dose-escalation study in a primate, the cynomolgus monkey, using hypofractionated stereotactic body radiotherapy in 13 animals. Results: At doses ≥40 Gy, animals developed a systemic syndrome resembling human radiation-induced liver disease, consisting of decreased albumin, elevated alkaline phosphatase, loss of appetite, ascites, and normal bilirubin. Higher radiation doses were lethal, causing severe disease that required euthanasia approximately 10 weeks after radiation. Even at lower doses in which radiation-induced liver disease was mild or nonexistent, latent and significant injury to hepatocytes was demonstrated by asialoglycoprotein-mediated functional imaging. These monkeys developed hepatic failure with encephalopathy when they received parenteral nutrition containing high concentrations of glucose. Histologically, livers showed central obstruction via an unusual intimal swelling that progressed to central fibrosis. Conclusions: The cynomolgus monkey, as the first animal model of human veno-occlusive radiation-induced liver disease, provides a resource for characterizing the early changes and pathogenesis of venocclusion, for establishing nonlethal therapeutic dosages, and for examining experimental therapies to minimize radiation injury

  3. E4orf1 improves lipid and glucose metabolism in hepatocytes: a template to improve steatosis & hyperglycemia.

    Directory of Open Access Journals (Sweden)

    Emily J Dhurandhar

    Full Text Available Hepatic steatosis often accompanies obesity and insulin resistance. The cornerstones of steatosis treatment include reducing body weight and dietary fat intake, which are marginally successful over the long term. Ad36, a human adenovirus, may offer a template to overcome these limitations. In vitro and in vivo studies collectively indicate that via its E4orf1 protein, Ad36 improves hyperglycemia, and attenuates hepatic steatosis, despite a high fat diet and without weight loss. Considering that hepatic insulin sensitivity, or the synthesis, oxidation, or export of fatty acid by hepatocytes are the key determinant of hepatic lipid storage, we determined the role of E4orf1 protein in modulating these physiological pathways. For this study, HepG2 cells, or mouse primary hepatocytes were transfected with E4orf1 or the null vector. Glucose output by hepatocytes was determined under gluconeogenic conditions (cAMP and dexamethasone, or glucagon exposure. Also, de-novo lipogenesis, palmitate oxidation, and lipid export as determined by apoB secretion were measured 48 h post transfection. Results show that compared to null vector transfected cells, E4orf1 significantly reduced glucose output in basal and gluconeogenic conditions. E4orf1 reduced de-novo lipogenesis by about 35%, increased complete fatty acid oxidation 2-fold (p<0.0001, and apoB secretion 1.5 fold(p<0.003. Response of key signaling molecules to E4orf1 transfection was in agreement with these findings. Thus, E4orf1 offers a valuable template to exogenously modulate hepatic glucose and lipid metabolism. Elucidating the underlying molecular mechanism may help develop therapeutic approaches for treating diabetes or non-alcoholic fatty liver disease(NAFLD.

  4. The Mallory body: morphological, clinical and experimental studies (Part 1 of a literature survey)

    DEFF Research Database (Denmark)

    Jensen, K; Gluud, C

    1994-01-01

    electron microscopy (with fibrillar structure parallel, random or absent), they remain stereotypical manifestations of hepatocyte injury. A summary of the conditions associated with Mallory bodies in the literature and their validity and potential etiological relationships is presented and discussed...... suggest a hit-and-run effect of alcohol, whereas other chronic liver diseases show evidence of gradual increase in prevalence of Mallory bodies with severity of hepatic pathology. Mallory bodies in cirrhosis do not imply alcoholic pathogenesis. Obesity, however, is associated with alcoholism and diabetes...

  5. Self-assembly model, hepatocytes attachment and inflammatory response for silk fibroin/chitosan scaffolds

    International Nuclear Information System (INIS)

    She Zhending; Feng Qingling; Liu Weiqiang

    2009-01-01

    Silk fibroin is an attractive natural fibrous protein for biomedical application due to its good biocompatibility and high tensile strength. Silk fibroin is apt to form a sheet-like structure during the freeze-drying process, which is not suitable for the scaffold of tissue engineering. In our former study, the adding of chitosan promoted the self-assembly of silk fibroin/chitosan (SFCS) into a three-dimensional (3D) homogeneous porous structure. In this study, a model of the self-assembly is proposed; furthermore, hepatocytes attachment and inflammatory response for the SFCS scaffold were examined. The rigid chain of chitosan may be used as a template for β-sheet formation of silk fibroin, and this may break the sheet structure of the silk fibroin scaffold and promote the formation of a 3D porous structure of the SFCS scaffold. Compared with the polylactic glycolic acid scaffold, the SFCS scaffold further facilitates the attachment of hepatocytes. To investigate the inflammatory response, SFCS scaffolds were implanted into the greater omentum of rats. From the results of implantation, we could demonstrate in vivo that the implantation of SFCS scaffolds resulted in only slight inflammation. Keeping the good histocompatibility and combining the advantages of both fibroin and chitosan, the SFCS scaffold could be a prominent candidate for soft tissue engineering, for example, in the liver.

  6. Self-assembly model, hepatocytes attachment and inflammatory response for silk fibroin/chitosan scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    She Zhending; Feng Qingling [State Key Laboratory of New Ceramics and Fine Processing, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Liu Weiqiang, E-mail: biomater@mail.tsinghua.edu.c [Center for Advanced Materials and Biotechnology, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057 (China)

    2009-08-15

    Silk fibroin is an attractive natural fibrous protein for biomedical application due to its good biocompatibility and high tensile strength. Silk fibroin is apt to form a sheet-like structure during the freeze-drying process, which is not suitable for the scaffold of tissue engineering. In our former study, the adding of chitosan promoted the self-assembly of silk fibroin/chitosan (SFCS) into a three-dimensional (3D) homogeneous porous structure. In this study, a model of the self-assembly is proposed; furthermore, hepatocytes attachment and inflammatory response for the SFCS scaffold were examined. The rigid chain of chitosan may be used as a template for beta-sheet formation of silk fibroin, and this may break the sheet structure of the silk fibroin scaffold and promote the formation of a 3D porous structure of the SFCS scaffold. Compared with the polylactic glycolic acid scaffold, the SFCS scaffold further facilitates the attachment of hepatocytes. To investigate the inflammatory response, SFCS scaffolds were implanted into the greater omentum of rats. From the results of implantation, we could demonstrate in vivo that the implantation of SFCS scaffolds resulted in only slight inflammation. Keeping the good histocompatibility and combining the advantages of both fibroin and chitosan, the SFCS scaffold could be a prominent candidate for soft tissue engineering, for example, in the liver.

  7. Proteomic Characterization of Primary Mouse Hepatocytes in Collagen Monolayer and Sandwich Culture.

    Science.gov (United States)

    Orsini, Malina; Sperber, Saskia; Noor, Fozia; Hoffmann, Esther; Weber, Susanne N; Hall, Rabea A; Lammert, Frank; Heinzle, Elmar

    2018-01-01

    Dedifferentiation of primary hepatocytes in vitro makes their application in long-term studies difficult. Embedding hepatocytes in a sandwich of extracellular matrix is reported to delay the dedifferentiation process to some extent. In this study, we compared the intracellular proteome of primary mouse hepatocytes (PMH) in conventional monolayer cultures (ML) to collagen sandwich culture (SW) after 1 day and 5 days of cultivation. Quantitative proteome analysis of PMH showed no differences between collagen SW and ML cultures after 1 day. Glycolysis and gluconeogenesis were strongly affected by long-term cultivation in both ML and SW cultures. Interestingly, culture conditions had no effect on cellular lipid metabolism. After 5 days, PMH in collagen SW and ML cultures exhibit characteristic indications of oxidative stress. However, in the SW culture the defense system against oxidative stress is significantly up-regulated to deal with this, whereas in the ML culture a down-regulation of these important enzymes takes place. Regarding the multiple effects of ROS and oxidative stress in cells, we conclude that the down-regulation of these enzymes seem to play a role in the loss of hepatic function observed in the ML cultivation. In addition, enzymes of the urea cycle were clearly down-regulated in ML culture. Proteomics confirms lack in oxidative stress defense mechanisms as the major characteristic of hepatocytes in monolayer cultures compared to sandwich cultures. J. Cell. Biochem. 119: 447-454, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  8. Changes in Expression of Connexin 32, Bile Canaliculus-Like Structures, and Localization of Alkaline Phosphatase in Primary Cultures of Fetal Rat Hepatocytes

    International Nuclear Information System (INIS)

    Fukazawa, Shoko; Chida, Kohsuke; Taguchi, Meiko; Takeuchi, Akihiro; Ikeda, Noriaki

    2013-01-01

    We devised an experimental design in primary cultures of fetal rat hepatocytes for studying hepatocyte differentiation over a short period. In the present study, hepatocytes were first cultured for 3 days in dexamethasone-supplemented medium and then for an additional 3 days in dexamethasone- or epidermal growth factor-supplemented medium. In hepatocytes cultured continuously in dexamethasone-supplemented medium, the expression of connexin 32 increased and bile canaliculus-like structures and localization of alkaline phosphatase in the plasma membrane around bile canaliculus-like structures were maintained. Few cells incorporated bromodeoxyuridine. On the other hand, in most of the hepatocytes cultured in epidermal growth factor-supplemented medium, the expression of connexin 32 was minimally recognized, bile canaliculus-like structures were shortened or eliminated, and alkaline phosphatase was localized as numerous fine spots throughout the cytoplasm. More than 20% of all hepatocytes incorporated bromodeoxyuridine. The present study suggests that in hepatocytes, there is a close relationship among connexin 32 expression, the maintenance of bile canaliculus-like structures, and the localization of alkaline phosphatase to the plasma membrane around the bile canaliculus-like structures, and this indicates that the present experimental model is useful for studying hepatocyte differentiation over a short period

  9. 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. © 2016 Society for Endocrinology.

  10. Diclofenac inhibits tumor necrosis factor-a-induced nuclear factor-kB activation causing synergic hepatocyte apoptosis

    NARCIS (Netherlands)

    Frederiksson, L; Herpers, B; Benedetti, G; Matadin, Q; Puigvert, J.C.; de Bont, H; Dragovic, S.; Vermeulen, N.P.E.; Commandeur, J.N.M.; Danen, E; de Graauw, M; van de Water, B.

    2011-01-01

    Drug-induced liver injury (DILI) is an important clinical problem. It involves crosstalk between drug toxicity and the immune system, but the exact mechanism at the cellular hepatocyte level is not well understood. Here we studied the mechanism of crosstalk in hepatocyte apoptosis caused by

  11. Differentiation of human umbilical cord mesenchymal stromal cells into low immunogenic hepatocyte-like cells.

    Science.gov (United States)

    Zhao, Qinjun; Ren, Hongying; Li, Xiyuan; Chen, Zhong; Zhang, Xiangyu; Gong, Wei; Liu, Yongjun; Pang, Tianxiang; Han, Zhong Chao

    2009-01-01

    Mesenchymal stromal cells (MSC) isolated from several human tissues have been known to differentiate into the hepatic lineage in vitro, but the immunogenicity of the differentiated hepatocyte-like cells (DHC) has not been reported. Umbilical cord (UC) MSC are thought to be an attractive cell source for cell therapy because of their young age and low infection rate compared with adult tissue MSC. Hepatic differentiation of UC-MSC was induced with a 2-step protocol. The expressions of hepatic markers were detected by RT-PCR and immunofluorescence staining. Albumin production and urea secretion were measured by ELISA and colorimetric assay respectively. The immunosuppressive properties of DHC was detected by mixed lymphocyte culture. After incubation with specific growth factors, including hepatocyte growth factor (HGF) and basic fibroblast growth factor (bFGF), UC MSC exhibited a high hepatic differentiation ability in an adherent culture condition. The differentiated UC MSC showed hepatocyte-like morphology and expressed several liver-specific markers at gene and protein levels. Furthermore, the DHC exhibited hepatocyte-specific functions, including albumin secretion, low-density lipoprotein uptake and urea production. More importantly, DHC did not express major histocompatibility complex (MHC) II antigen and were not able to induce lymphocyte proliferation in mixed lymphocyte culture, as undifferentiated UC MSC did. Our results indicate that UC MSC are able to differentiate into functional hepatocyte-like cells that still retain their low immunogenicity in vitro. More importantly, DHC incorporated into the parenchyma of liver when transplanted into mice with CCl(4)-induced liver injury. Therefore, DHC may be an ideal source for cell therapy of liver diseases.

  12. 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.

  13. Insulin-like growth factor-II receptors in cultured rat hepatocytes: regulation by cell density

    International Nuclear Information System (INIS)

    Scott, C.D.; Baxter, R.C.

    1987-01-01

    Insulin-like growth factor-II (IGF-II) receptors in primary cultures of adult rat hepatocytes were characterized and their regulation by cell density examined. In hepatocytes cultured at 5 X 10(5) cells per 3.8 cm2 plate [ 125 I]IGF-II bound to specific, high affinity receptors (Ka = 4.4 +/- 0.5 X 10(9) l/mol). Less than 1% cross-reactivity by IGF-I and no cross-reactivity by insulin were observed. IGF-II binding increased when cells were permeabilized with 0.01% digitonin, suggesting the presence of an intracellular receptor pool. Determined by Scatchard analysis and by polyacrylamide gel electrophoresis after affinity labeling, the higher binding was due solely to an increase in binding sites present on 220 kDa type II IGF receptors. In hepatocytes cultured at low densities, the number of cell surface receptors increased markedly, from 10-20,000 receptors per cell at a culture density of 6 X 10(5) cells/well to 70-80,000 receptors per cell at 0.38 X 10(5) cells/well. The increase was not due simply to the exposure of receptors from the intracellular pool, as a density-related increase in receptors was also seen in cells permeabilized with digitonin. There was no evidence that IGF binding proteins, either secreted by hepatocytes or present in fetal calf serum, had any effect on the measurement of receptor concentration or affinity. We conclude that rat hepatocytes in primary culture contain specific IGF-II receptors and that both cell surface and intracellular receptors are regulated by cell density

  14. Differentiation of hepatocytes from induced pluripotent stem cells derived from human hair follicle mesenchymal stem cells.

    Science.gov (United States)

    Shi, Xu; Lv, Shuang; He, Xia; Liu, Xiaomei; Sun, Meiyu; Li, Meiying; Chi, Guangfan; Li, Yulin

    2016-10-01

    Due to the limitations of organ donors and immune rejection in severe liver diseases, stem cell-based therapy presents a promising application for tissue repair and regeneration. As a novel cell source, mesenchymal stem cells separated from human hair follicles (HF-MSCs) are convenient to obtain and have no age limit. To date, the differentiation of HF-MSCs into hepatocytes has not been reported. In this study, we explored whether HF-MSCs and HF-MSC-derived-induced pluripotent stem cells (HF-iPS) could differentiate into hepatocytes in vitro. Flow cytometry, Oil Red O stain and Alizarin Red stain were used to identify the characteristics of HF-MSCs. The expression of liver-specific gene was detected by immunofluorescence and Quantitative Polymerase Chain Reaction. Periodic Acid-Schiff stain, Indocyanine Green stain and Low-Density Lipoprotein stain were performed to evaluate the functions of induced hepatocyte-like cells (HLCs). HF-MSCs were unable to differentiate into HLCs using previously reported procedures for MSCs from other tissues. However, HF-iPS efficiently induced the generation of HLCs that expressed hepatocyte markers and drug metabolism-related genes. HF-iPS can be used as novel and alternative cellular tools for inducing hepatocytes in vitro, simultaneously benefiting from utilizing HF-MSCs as a noninvasive and convenient cell source for reprogramming.

  15. Titanium Dioxide Nanoparticles Trigger Loss of Function and Perturbation of Mitochondrial Dynamics in Primary Hepatocytes.

    Directory of Open Access Journals (Sweden)

    Vaishaali Natarajan

    Full Text Available Titanium dioxide (TiO2 nanoparticles are one of the most highly manufactured and employed nanomaterials in the world with applications in copious industrial and consumer products. The liver is a major accumulation site for many nanoparticles, including TiO2, directly through intentional exposure or indirectly through unintentional ingestion via water, food or animals and increased environmental contamination. Growing concerns over the current usage of TiO2 coupled with the lack of mechanistic understanding of its potential health risk is the motivation for this study. Here we determined the toxic effect of three different TiO2 nanoparticles (commercially available rutile, anatase and P25 on primary rat hepatocytes. Specifically, we evaluated events related to hepatocyte functions and mitochondrial dynamics: (1 urea and albumin synthesis using colorimetric and ELISA assays, respectively; (2 redox signaling mechanisms by measuring reactive oxygen species (ROS production, manganese superoxide dismutase (MnSOD activity and mitochondrial membrane potential (MMP; (3 OPA1 and Mfn-1 expression that mediates the mitochondrial dynamics by PCR; and (4 mitochondrial morphology by MitoTracker Green FM staining. All three TiO2 nanoparticles induced a significant loss (p < 0.05 in hepatocyte functions even at concentrations as low as 50 ppm with commercially used P25 causing maximum damage. TiO2 nanoparticles induced a strong oxidative stress in primary hepatocytes. TiO2 nanoparticles exposure also resulted in morphological changes in mitochondria and substantial loss in the fusion process, thus impairing the mitochondrial dynamics. Although this study demonstrated that TiO2 nanoparticles exposure resulted in substantial damage to primary hepatocytes, more in vitro and in vivo studies are required to determine the complete toxicological mechanism in primary hepatocytes and subsequently liver function.

  16. Metabolism of six CYP probe substrates in fetal hepatocytes

    Directory of Open Access Journals (Sweden)

    Abdul Naveed Shaik

    2016-06-01

    Full Text Available Cytochrome P-450 (CYP are the most common drug metabolizing enzymes and are abundantly expressed in liver apart from kidney, lungs, intestine, brain etc. Their expression levels change with physiological conditions and disease states. The expression of these CYPs is less in human foetus and neonates compared to adults, which results in lower clearance of xenobiotics in infants and neonates compared to adults. Hepatocytes are the cells which are largely used to study these CYPs. We have isolated hepatocytes from aborted foetus to study the metabolism of six probe substrates: phenacetin, diclofenac, S-mephenytoin, dextromethorphan, nifedipine and testosterone. The results obtained show the expression of various CYPs (CYP1A2, CYP2C19, CYP2C9, CYP2D6, and CYP3A4 in human foetus and their involvement in metabolism of CYP probe substrates.

  17. [Study on the interface of human hepatocyte/micropore polypropylene ultrafiltration membrane].

    Science.gov (United States)

    Peng, Cheng-Hong; Han, Bao-San; Gao, Chang-You; Ma, Zu-Wei; Zhao, Zhi-Ming; Wang, Yong; Liu, Hong; Zhang, Gui-di; Yang, Mei-Juan

    2004-09-02

    To found a new interface of human hepatocyte/micropore polypropylene ultrafiltration membrane (MPP) with good cytocompatibility so as to construct bioartificial bioreactor with polypropylene hollow fibers in future. MPP ultrafiltration membrane underwent chemical grafting modification through ultraviolet irradiation and Fe(2+) reduction. The contact angles of MPP and the modified MPP membranes were measured. Human hepatic cells L-02 were cultured. MPP and modified MPP membranes were spread on the wells of culture plate and human hepatic cells and cytodex 3 were inoculated on them. Different kinds of microscopy were used to observe the morphology of these cells. The water contact angle of MPP and the modified MPP membranes decreased from 78 degrees +/- 5 degrees to 27 degrees +/- 4 degrees (P < 0.05), which indicated that the hydrophilicity of the membrane was improved obviously after the grafting modification. Human hepatocyte L-02 did not adhere to and spread on the modified MPP membrane surface, and only grew on the microcarrier cytodex 3 with higher density and higher proliferation ratio measured by MTT. Grafting modification of acrylamide on MPP membrane is a good method to improve the human hepatocyte cytocompatibility with MPP ultrafiltration membrane.

  18. Enhancement of the predicted drug hepatotoxicity in gel entrapped hepatocytes within polysulfone-g-poly (ethylene glycol) modified hollow fiber

    International Nuclear Information System (INIS)

    Shen Chong; Zhang Guoliang; Meng Qin

    2010-01-01

    Collagen gel-based 3D cultures of hepatocytes have been proposed for evaluation of drug hepatotoxicity because of their more reliability than traditional monolayer culture. The collagen gel entrapment of hepatocytes in hollow fibers has been proven to well reflect the drug hepatotoxicity in vivo but was limited by adsorption of hydrophobic drugs onto hollow fibers. This study aimed to investigate the impact of hollow fibers on hepatocyte performance and drug hepatotoxicity. Polysulfone-g-poly (ethylene glycol) (PSf-g-PEG) hollow fiber was fabricated and applied for the first time to suppress the drug adsorption. Then, the impact of hollow fibers was evaluated by detecting the hepatotoxicity of eight selected drugs to gel entrapped hepatocytes within PSf and PSf-g-PEG hollow fibers, or without hollow fibers. The hepatocytes in PSf-g-PEG hollow fiber showed the highest sensitivity to drug hepatotoxicity, while those in PSf hollow fiber and cylindrical gel without hollow fiber underestimated the hepatotoxicity due to either drug adsorption or low hepatic functions. Therefore, the 3D culture of gel entrapped hepatocytes within PSf-g-PEG hollow fiber would be a promising tool for investigation of drug hepatotoxicity in vitro.

  19. Indole-3-carbinol, but not its major digestive product 3,3'-diindolylmethane, induces reversible hepatocyte hypertrophy and cytochromes P450

    International Nuclear Information System (INIS)

    Crowell, James A.; Page, John G.; Levine, Barry S.; Tomlinson, Michael J.; Hebert, Charles D.

    2006-01-01

    Indole-3-carbinol (I-3-C) and 3,3'-diindolylmethane (DIM) have been shown to reduce the incidence and multiplicity of cancers in laboratory animal models. Based on the observation that I-3-C induced hepatocyte hypertrophy when administered orally for 13 weeks to rats, a treatment and recovery study was undertaken to test the hypothesis that the induction of hepatocyte hypertrophy and cytochrome P450 (CYP) activity by I-3-C are adaptive, reversible responses. Additionally, we directly compared the effects of I-3-C to those of its principle metabolite DIM. Rats were treated orally for 28 days with 2 doses of I-3-C (5 and 50 mg I-3-C/kg body weight/day) and DIM (7.5 and 75 mg DIM/kg body weight/day) and then one-half of the animals were not treated for an additional 28 days. Organ weights, histopathology, and the CYP enzyme activities of 1A1/2, 2B1/2, 2C9, 2D6, 2E1, 3A4, and 19 A were measured both after treatment and after recovery. Oral administration of 50 mg I-3-C/kg body weight/day to rats for 28 days significantly increased liver weights and CYP enzyme activities. The effects in males were more pronounced and persistent after recovery than the effects in females. The increased organ weights returned to control values after treatment. Conversely, DIM did not alter liver weights and had no effect on CYP activities after the 28-day treatment. Some changes in CYP activities were measured after the DIM recovery period but the magnitudes of the changes were considered biologically insignificant. The results show that I-3-C, but not DIM, induces reversible adaptive responses in the liver

  20. Isolation of Kupffer Cells and Hepatocytes from a Single Mouse Liver

    DEFF Research Database (Denmark)

    Aparicio-Vergara, Marcela; Tencerova, Michaela; Morgantini, Cecilia

    2017-01-01

    Liver perfusion is a common technique used to isolate parenchymal and non-parenchymal liver cells for in vitro experiments. This method allows hepatic cells to be separated based on their size and weight, by centrifugation using a density gradient. To date, other methods allow the isolation of only...... one viable hepatic cellular fraction from a single mouse; either parenchymal (hepatocytes) or non-parenchymal cells (i.e., Kupffer cells or hepatic stellate cells). Here, we describe a method to isolate both hepatocytes and Kupffer cells from a single mouse liver, thereby providing the unique...... advantage of studying different liver cell types that have been isolated from the same organism....

  1. Liver system. V. Activation-extinction line of cyclic hepatocyte activities.

    Science.gov (United States)

    Dioguardi, N; Brambilla, F; Dell'Oca, M; Arosio, E; Parmeggiani, L

    1991-01-01

    The excitation-extintion line of hepatocytes from an inert state towards the stabilization of a given activity is described. Within the cell, the switching on of any given activity is a competitive process among different activities. The process is driven by the influence field created in the environment of the Rappaport acinus by sinusoidal blood which changes its characteristics during its passage from the portal zone to the central vein. Every step of the excitation-extintion pathway follows the so-called law of autoisodiasostasis (AIS), i.e. it is characterized by an oscillatory motion between restoring (homopoiesis or HP) and working (homeorhesis or HR) states. Since the cyclical bistable equilibrium of AIS characterizes all conditions of hepatocyte activities, the AIS cycle can be defined a limit cycle.

  2. Detection of Hepatocyte Clones Containing Integrated Hepatitis B Virus DNA Using Inverse Nested PCR.

    Science.gov (United States)

    Tu, Thomas; Jilbert, Allison R

    2017-01-01

    Chronic hepatitis B virus (HBV) infection is a major cause of liver cirrhosis and hepatocellular carcinoma (HCC), leading to ~600,000 deaths per year worldwide. Many of the steps that occur during progression from the normal liver to cirrhosis and/or HCC are unknown. Integration of HBV DNA into random sites in the host cell genome occurs as a by-product of the HBV replication cycle and forms a unique junction between virus and cellular DNA. Analyses of integrated HBV DNA have revealed that HCCs are clonal and imply that they develop from the transformation of hepatocytes, the only liver cell known to be infected by HBV. Integrated HBV DNA has also been shown, at least in some tumors, to cause insertional mutagenesis in cancer driver genes, which may facilitate the development of HCC. Studies of HBV DNA integration in the histologically normal liver have provided additional insight into HBV-associated liver disease, suggesting that hepatocytes with a survival or growth advantage undergo high levels of clonal expansion even in the absence of oncogenic transformation. Here we describe inverse nested PCR (invPCR), a highly sensitive method that allows detection, sequencing, and enumeration of virus-cell DNA junctions formed by the integration of HBV DNA. The invPCR protocol is composed of two major steps: inversion of the virus-cell DNA junction and single-molecule nested PCR. The invPCR method is highly specific and inexpensive and can be tailored to DNA extracted from large or small amounts of liver. This procedure also allows detection of genome-wide random integration of any known DNA sequence and is therefore a useful technique for molecular biology, virology, and genetic research.

  3. Short-term exercise reduces markers of hepatocyte apoptosis in nonalcoholic fatty liver disease

    DEFF Research Database (Denmark)

    Fealy, Ciaran E; Haus, Jacob M; Solomon, Thomas

    2012-01-01

    and after the exercise intervention. The Matsuda index was used to assess insulin sensitivity. We observed significant decreases in CK18 fragments (558.4 ± 106.8 vs. 323.4 ± 72.5 U/l, P vs. 24.3 ± 4.8 U/l, P vs. 69...... changes in fat oxidation and circulating sFasL (rho = -0.65, P vs. 17.5 ± 2.1%, NS). We conclude that short-term exercise reduces a circulatory marker of hepatocyte apoptosis in obese individuals with NAFLD and propose that changes....... We therefore examined the effect of a short-term exercise program on markers of apoptosis-plasma cytokeratin 18 (CK18) fragments, alanine aminotransferase (ALT), aspartate aminotransferase (AST), soluble Fas (sFas), and sFas ligand (sFasL)-in 13 obese individuals with NAFLD [body mass index 35.2 ± 1...

  4. Hepatocytes Determine the Hypoxic Microenvironment and Radiosensitivity of Colorectal Cancer Cells Through Production of Nitric Oxide That Targets Mitochondrial Respiration

    International Nuclear Information System (INIS)

    Jiang, Heng; Verovski, Valeri N.; Leonard, Wim; Law, Ka Lun; Vermeersch, Marieke; Storme, Guy; Van den Berge, Dirk; Gevaert, Thierry; Sermeus, Alexandra; De Ridder, Mark

    2013-01-01

    Purpose: To determine whether host hepatocytes may reverse hypoxic radioresistance through nitric oxide (NO)-induced oxygen sparing, in a model relevant to colorectal cancer (CRC) liver metastases. Methods and Materials: Hepatocytes and a panel of CRC cells were incubated in a tissue-mimetic coculture system with diffusion-limited oxygenation, and oxygen levels were monitored by an oxygen-sensing fluorescence probe. To activate endogenous NO production, cocultures were exposed to a cytokine mixture, and the expression of inducible nitric oxide synthase was analyzed by reverse transcription–polymerase chain reaction, Western blotting, and NO/nitrite production. The mitochondrial targets of NO were examined by enzymatic activity. To assess hypoxic radioresponse, cocultures were irradiated and reseeded for colonies. Results: Resting hepatocytes consumed 10-40 times more oxygen than mouse CT26 and human DLD-1, HT29, HCT116, and SW480 CRC cells, and thus seemed to be the major effectors of hypoxic conditioning. As a result, hepatocytes caused uniform radioprotection of tumor cells at a 1:1 ratio. Conversely, NO-producing hepatocytes radiosensitized all CRC cell lines more than 1.5-fold, similar to the effect of selective mitochondrial inhibitors. The radiosensitizing effect was associated with a respiratory self-arrest of hepatocytes at the level of aconitase and complex II, which resulted in profound reoxygenation of tumor cells through oxygen sparing. Nitric oxide–producing hepatocytes were at least 10 times more active than NO-producing macrophages to reverse hypoxia-induced radioresistance. Conclusions: Hepatocytes were the major determinants of the hypoxic microenvironment and radioresponse of CRC cells in our model of metabolic hypoxia. We provide evidence that reoxygenation and radiosensitization of hypoxic CRC cells can be achieved through oxygen sparing induced by endogenous NO production in host hepatocytes

  5. Hepatocytes Determine the Hypoxic Microenvironment and Radiosensitivity of Colorectal Cancer Cells Through Production of Nitric Oxide That Targets Mitochondrial Respiration

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Heng; Verovski, Valeri N.; Leonard, Wim; Law, Ka Lun; Vermeersch, Marieke; Storme, Guy; Van den Berge, Dirk; Gevaert, Thierry; Sermeus, Alexandra [Department of Radiotherapy, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel, Brussels (Belgium); De Ridder, Mark, E-mail: mark.deridder@uzbrussel.be [Department of Radiotherapy, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel, Brussels (Belgium)

    2013-03-01

    Purpose: To determine whether host hepatocytes may reverse hypoxic radioresistance through nitric oxide (NO)-induced oxygen sparing, in a model relevant to colorectal cancer (CRC) liver metastases. Methods and Materials: Hepatocytes and a panel of CRC cells were incubated in a tissue-mimetic coculture system with diffusion-limited oxygenation, and oxygen levels were monitored by an oxygen-sensing fluorescence probe. To activate endogenous NO production, cocultures were exposed to a cytokine mixture, and the expression of inducible nitric oxide synthase was analyzed by reverse transcription–polymerase chain reaction, Western blotting, and NO/nitrite production. The mitochondrial targets of NO were examined by enzymatic activity. To assess hypoxic radioresponse, cocultures were irradiated and reseeded for colonies. Results: Resting hepatocytes consumed 10-40 times more oxygen than mouse CT26 and human DLD-1, HT29, HCT116, and SW480 CRC cells, and thus seemed to be the major effectors of hypoxic conditioning. As a result, hepatocytes caused uniform radioprotection of tumor cells at a 1:1 ratio. Conversely, NO-producing hepatocytes radiosensitized all CRC cell lines more than 1.5-fold, similar to the effect of selective mitochondrial inhibitors. The radiosensitizing effect was associated with a respiratory self-arrest of hepatocytes at the level of aconitase and complex II, which resulted in profound reoxygenation of tumor cells through oxygen sparing. Nitric oxide–producing hepatocytes were at least 10 times more active than NO-producing macrophages to reverse hypoxia-induced radioresistance. Conclusions: Hepatocytes were the major determinants of the hypoxic microenvironment and radioresponse of CRC cells in our model of metabolic hypoxia. We provide evidence that reoxygenation and radiosensitization of hypoxic CRC cells can be achieved through oxygen sparing induced by endogenous NO production in host hepatocytes.

  6. Induction of highly functional hepatocytes from human umbilical cord mesenchymal stem cells by HNF4α transduction.

    Directory of Open Access Journals (Sweden)

    Hualian Hang

    Full Text Available To investigate the differentiation potential of human umbilical mesenchymal stem cells (HuMSCs and the key factors that facilitate hepatic differentiation.HuMSCs were induced to become hepatocyte-like cells according to a previously published protocol. The differentiation status of the hepatocyte-like cells was examined by observing the morphological changes under an inverted microscope and by immunofluorescence analysis. Hepatocyte nuclear factor 4 alpha (HNF4α overexpression was achieved by plasmid transfection of the hepatocyte-like cells. The expression of proteins and genes of interest was then examined by Western blotting and reverse transcription-polymerase chain reaction (RT-PCR or real-time RT-PCR methods.Our results demonstrated that HuMSCs can easily be induced into hepatocyte-like cells using a published differentiation protocol. The overexpression of HNF4α in the induced HuMSCs significantly enhanced the expression levels of hepatic-specific proteins and genes. HNF4α overexpression may be associated with liver-enriched transcription factor networks and the Wnt/β-Catenin pathway.The overexpression of HNF4α improves the hepatic differentiation of HuMSCs and is a simple way to improve cellular sources for clinical applications.

  7. 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 parti...

  8. Effects of dehydroepiandrosterone (DHEA) on glucose metabolism in isolated hepatocytes from Zucker rats

    International Nuclear Information System (INIS)

    Finan, A.; Cleary, M.P.

    1986-01-01

    DHEA has been shown to competitively inhibit the pentose phosphate shunt (PPS) enzyme glucose-6-phosphate dehydrogenase (G6PD) when added in vitro to supernatants or homogenates prepared from mammalian tissues. However, no consistent effect on G6PD activity has been determined in tissue removed from DHEA-treated rats. To explore the effects of DHEA on PPS, glucose utilization was measured in hepatocytes from lean and obese male Zucker rats (8 wks of age) following 1 wk of DHEA treatment (0.6% in diet). Incubation of isolated hepatocytes from treated lean Zucker rats with either [1- 14 C] glucose or [6- 14 C] glucose resulted in significant decreases in CO 2 production and total glucose utilization. DHEA-lean rats also had lowered fat pad weights. In obese rats, there was no effect of 1 wk of treatment on either glucose metabolism or fat pad weight. The calculated percent contribution of the PPS to glucose metabolism in hepatocytes was not changed for either DHEA-lean or obese rats when compared to control rats. In conclusion, 1 wk of DHEA treatment lowered overall glucose metabolism in hepatocytes of lean Zucker rats, but did not selectively affect the PPS. The lack of an effect of short-term treatment in obese rats may be due to differences in their metabolism or storage/release of DHEA in tissues in comparison to lean rats

  9. Metabolism of the synthetic cannabinoid 5F-PY-PICA by human and rat hepatocytes and identification of biliary analytical targets by directional efflux in sandwich-cultured rat hepatocytes using UHPLC-HR-MS/MS

    DEFF Research Database (Denmark)

    Mardal, Marie; Annaert, Pieter; Noble, Carolina

    2018-01-01

    Analytical strategies for detecting drugs in biological samples rely on information on metabolism and elimination. 5F-PY-PICA belongs to the group of synthetic cannabinoids that are known to undergo excretion into the bile. The aims of this study were the in vitro identification of metabolites of 5......F-PY-PICA and to determine which analytical targets are excreted into the bile and urine. Metabolites identified after incubation of 5F-PY-PICA with pooled human liver microsomes (pHLM), pooled human hepatocytes (pHH), or suspended and sandwich-cultured rat hepatocytes (SCRH). Rat hepatocytes were......-PY-PICA, M4, and M22 are proposed as analytical targets for bile analysis in forensic screening protocols, whereas M6 should be one of the main urinary targets for 5F-PY-PICA analysis....

  10. Implications of the simultaneous occurrence of glycolysis and gluconeogenesis in hepatocytes from normal and hyperthyroid rats

    International Nuclear Information System (INIS)

    Phillips, J.W.; Berry, M.N.

    2001-01-01

    The mammalian liver has the capability for both glycolysis and gluconeogenesis. In the fasting state, metabolites such as lactate and glycerol, generated in the peripheral tissues, are taken up by the liver and converted to glucose. However, hepatocytes from fasted animals are also capable of substantial rates of glycolysis. It is generally assumed that glycolysis and gluconeogenesis do not occur simultaneously in the same cell, but rather the metabolic conditions that facilitate flux through one pathway impair flow in the opposite direction. The actual direction of flow at any given moment is thought to be determined by regulatory mechanisms that control flux through the enzymatic steps specific to glycolysis and gluconeogenesis. The rates of glycolysis from [6- 3 H]glucose and gluconeogenesis from [U- 14 C]glycerol were determined in isolated hepatocytes from fasted normal and hyperthyroid rats. We observed that glycolysis from glucose and glucose synthesis from glycerol occurred simultaneously at substantial rates in hepatocytes from normal rats and that gluconeogenesis, but not glycolysis, was increased twofold in hepatocytes from thyroid treated rats. In the hyperthyroid state, the rate of glycolysis from glucose was approximately equal to the rate of glucose formation from glycerol. Hence, metabolism and ATP turnover were stimulated without substantially altering steady-state concentrations of glucose. The concomitant operation of hepatic glycolysis and gluconeogenesis may be a mechanism that accounts in part for the calorigenic effect of thyroid hormone. Since hepatocyles are generally impermeable to phosphorylated metabolites, our observations suggest that glycolysis, and phosphorylation of glycerol take place in the same cells, and that the occurrence of simultaneous glycolysis and gluconeogenesis is an indication of channelling within the hepatocyte cytoplasm of individual hepatocytes

  11. Connexin 32 and connexin 43 are involved in lineage restriction of hepatic progenitor cells to hepatocytes

    Directory of Open Access Journals (Sweden)

    Haiyun Pei

    2017-11-01

    Full Text Available Abstract Background Bi-potential hepatic progenitor cells can give rise to both hepatocytes and cholangiocytes, which is the last phase and critical juncture in terms of sequentially hepatic lineage restriction from any kind of stem cells. If their differentiation can be controlled, it might access to functional hepatocytes to develop pharmaceutical and biotechnology industries as well as cell therapies for end-stage liver diseases. Methods In this study, we investigated the influence of Cx32 and Cx43 on hepatocyte differentiation of WB-F344 cells by in vitro gain and loss of function analyses. An inhibitor of Cx32 was also used to make further clarification. To reveal p38 MAPK pathway is closely related to Cxs, rats with 70% partial hepatectomy were injected intraperitoneally with a p38 inhibitor, SB203580. Besides, the effects of p38 MAPK pathway on differentiation of hepatoblasts isolated from fetal rat livers were evaluated by addition of SB203580 in culture medium. Results In vitro gain and loss of function analyses showed overexpression of Connexin 32 and knockdown of Connexin 43 promoted hepatocytes differentiation from hepatic progenitor cells. In addition, in vitro and ex vivo research revealed inhibition of p38 mitogen-activated protein kinase pathway can improve hepatocytes differentiation correlating with upregulation of Connexin 32 expression and downregulation of Connexin 43 expression. Conclusions Here we demonstrate that Connexins play crucial roles in facilitating differentiation of hepatic progenitors. Our work further implicates that regulators of Connexins and their related pathways might provide new insights to improve lineage restriction of stem cells to mature hepatocytes.

  12. Xenobiotic-Metabolizing Enzyme and Transporter Gene Expression in Primary Cultures of Human Hepatocytes Modulated by Toxcast Chemicals

    Science.gov (United States)

    Primary human hepatocyte cultures are useful in vitro model systems of human liver because when cultured under appropriate conditions the hepatocytes retain liver-like functionality such as metabolism, transport, and cell signaling. This model system was used to characterize the ...

  13. Destruction of the hepatocyte junction by intercellular invasion of Leptospira causes jaundice in a hamster model of Weil's disease.

    Science.gov (United States)

    Miyahara, Satoshi; Saito, Mitsumasa; Kanemaru, Takaaki; Villanueva, Sharon Y A M; Gloriani, Nina G; Yoshida, Shin-ichi

    2014-08-01

    Weil's disease, the most severe form of leptospirosis, is characterized by jaundice, haemorrhage and renal failure. The mechanisms of jaundice caused by pathogenic Leptospira remain unclear. We therefore aimed to elucidate the mechanisms by integrating histopathological changes with serum biochemical abnormalities during the development of jaundice in a hamster model of Weil's disease. In this work, we obtained three-dimensional images of infected hamster livers using scanning electron microscope together with freeze-cracking and cross-cutting methods for sample preparation. The images displayed the corkscrew-shaped bacteria, which infiltrated the Disse's space, migrated between hepatocytes, detached the intercellular junctions and disrupted the bile canaliculi. Destruction of bile canaliculi coincided with the elevation of conjugated bilirubin, aspartate transaminase and alkaline phosphatase levels in serum, whereas serum alanine transaminase and γ-glutamyl transpeptidase levels increased slightly, but not significantly. We also found in ex vivo experiments that pathogenic, but not non-pathogenic leptospires, tend to adhere to the perijunctional region of hepatocyte couplets isolated from hamsters and initiate invasion of the intercellular junction within 1 h after co-incubation. Our results suggest that pathogenic leptospires invade the intercellular junctions of host hepatocytes, and this invasion contributes in the disruption of the junction. Subsequently, bile leaks from bile canaliculi and jaundice occurs immediately. Our findings revealed not only a novel pathogenicity of leptospires, but also a novel mechanism of jaundice induced by bacterial infection. © 2014 The Authors. International Journal of Experimental Pathology © 2014 International Journal of Experimental Pathology.

  14. The Protection of Hepatocyte Cells from the Effects of Oxidative Stress by Treatment with Vitamin E in Conjunction with DTT

    Directory of Open Access Journals (Sweden)

    Jen-Hsiang Tsai

    2010-01-01

    Full Text Available We investigated the effect of vitamin E on membrane protein thiols under oxidative stress, which we induced by treating hepatocytes with tert-butyl hydroperoxide (TBH for 60 mins. Those cells which we pretreated with vitamin E formed fewer blebs (22.3% compared to 60.0% in nonvitamin E-treated cells and maintained cytosolic calcium concentration and the number of membrane protein thiols instead of showing the usual symptoms in cells undergoing oxidative stress. Dithiothreitol (DTT also commonly reduces bleb formation in hepatocytes affected by TBH. However, our experiments clearly demonstrate that DTT does not prevent the changes in cytosolic calcium and membrane protein thiols in the blebbing cells. Consequently, we decided to pretreat cells with both DTT and vitamin E and found that the influence of TBH was entirely prevented. These findings may provide us with a new aspect for investigating the mechanism of bleb formation under oxidative stress.

  15. CXC chemokines function as a rheostat for hepatocyte proliferation and liver regeneration.

    Directory of Open Access Journals (Sweden)

    Gregory C Wilson

    Full Text Available Our previous in vitro studies have demonstrated dose-dependent effects of CXCR2 ligands on hepatocyte cell death and proliferation. In the current study, we sought to determine if CXCR2 ligand concentration is responsible for the divergent effects of these mediators on liver regeneration after ischemia/reperfusion injury and partial hepatectomy.Murine models of partial ischemia/reperfusion injury and hepatectomy were used to study the effect of CXCR2 ligands on liver regeneration.We found that hepatic expression of the CXCR2 ligands, macrophage inflammatory protein-2 (MIP-2 and keratinocyte-derived chemokine (KC, was significantly increased after both I/R injury and partial hepatectomy. However, expression of these ligands after I/R injury was 30-100-fold greater than after hepatectomy. Interestingly, the same pattern of expression was found in ischemic versus non-ischemic liver lobes following I/R injury with expression significantly greater in the ischemic liver lobes. In both systems, lower ligand expression was associated with increased hepatocyte proliferation and liver regeneration in a CXCR2-dependent fashion. To confirm that these effects were related to ligand concentration, we administered exogenous MIP-2 and KC to mice undergoing partial hepatectomy. Mice received a "high" dose that replicated serum levels found after I/R injury and a "low" dose that was similar to that found after hepatectomy. Mice receiving the "high" dose had reduced levels of hepatocyte proliferation and regeneration whereas the "low" dose promoted hepatocyte proliferation and regeneration.Together, these data demonstrate that concentrations of CXC chemokines regulate the hepatic proliferative response and subsequent liver regeneration.

  16. Tributyltin induces apoptotic signaling in hepatocytes through pathways involving the endoplasmic reticulum and mitochondria

    International Nuclear Information System (INIS)

    Grondin, Melanie; Marion, Michel; Denizeau, Francine; Averill-Bates, Diana A.

    2007-01-01

    Tri-n-butyltin is a widespread environmental toxicant, which accumulates in the liver. This study investigates whether tri-n-butyltin induces pro-apoptotic signaling in rat liver hepatocytes through pathways involving the endoplasmic reticulum and mitochondria. Tri-n-butyltin activated the endoplasmic reticulum pathway of apoptosis, which was demonstrated by the activation of the protease calpain, its translocation to the plasma membrane, followed by cleavage of the calpain substrates, cytoskeletal protein vinculin, and caspase-12. Caspase-12 is localized to the cytoplasmic side of the endoplasmic reticulum and is involved in apoptosis mediated by the endoplasmic reticulum. Tri-n-butyltin also caused translocation of the pro-apoptotic proteins Bax and Bad from the cytosol to mitochondria, as well as changes in mitochondrial membrane permeability, events which can activate the mitochondrial death pathway. Tri-n-butyltin induced downstream apoptotic events in rat hepatocytes at the nuclear level, detected by chromatin condensation and by confocal microscopy using acridine orange. We investigated whether the tri-n-butyltin-induced pro-apoptotic events in hepatocytes could be linked to perturbation of intracellular calcium homeostasis, using confocal microscopy. Tri-n-butyltin caused changes in intracellular calcium distribution, which were similar to those induced by thapsigargin. Calcium was released from a subcellular compartment, which is likely to be the endoplasmic reticulum, into the cytosol. Cytosolic acidification, which is known to trigger apoptosis, also occurred and involved the Cl - /HCO 3 - exchanger. Pro-apoptotic events in hepatocytes were inhibited by the calcium chelator, Bapta-AM, and by a calpain inhibitor, which suggests that changes in intracellular calcium homeostasis are involved in tri-n-butyltin-induced apoptotic signaling in rat hepatocytes

  17. Endocrine disruption screening by protein and gene expression of vitellogenin in freshly isolated and cryopreserved rainbow trout hepatocytes.

    Science.gov (United States)

    Markell, Lauren K; Mingoia, Robert T; Peterson, Heather M; Yao, Jianhong; Waters, Stephanie M; Finn, James P; Nabb, Diane L; Han, Xing

    2014-08-18

    Xenobiotics may activate the estrogen receptor, resulting in alteration of normal endocrine functions in animals and humans. Consequently, this necessitates development of assay end points capable of identifying estrogenic xenobiotics. In the present study, we screened the potential estrogenicity of chemicals via their ability to induce vitellogenin (VTG) expression in cultured primary hepatocytes from male trout. A routine method for VTG detection measures the secretion of the protein by enzyme-linked immunosorbent assay (ELISA) in freshly isolated trout hepatocytes. However, this lengthy (6 days) culturing procedure requires that hepatocyte isolation is performed each time the assay is run. We optimized this methodology by investigating the utility of cryopreserved hepatocytes, shortening the incubation time, performing a quantitative real-time PCR (qPCR) method for VTG quantification, and verifying the model system with reference chemicals 17β-estradiol, estrone, diethylstilbestrol, hexestrol, genistein, and a negative control, corticosterone. To test the performance of both freshly isolated and cryopreserved hepatocytes, mRNA was collected from hepatocytes following 24 h treatment for VTG gene expression analysis, whereas cell culture media was collected for a VTG ELISA 96 h post-treatment. EC50 values were obtained for each reference chemical except for corticosterone, which exhibited no induction of VTG gene or protein level. Our results show linear concordance between ELISA and qPCR detection methods. Although there was approximately 50% reduction in VTG inducibility following cryopreservation, linear concordance of EC50 values was found between freshly isolated and cryopreserved hepatocytes, indicating that cryopreservation does not alter the functional assessment of estrogen receptor activation and therefore VTG expression. These studies demonstrate that qPCR is a sensitive and specific method for detecting VTG gene expression that can be used together

  18. Activated Hepatic Stellate Cells Induce Tumor Progression of Neoplastic Hepatocytes in a TGF-β Dependent Fashion

    Science.gov (United States)

    MIKULA, M.; PROELL, V.; FISCHER, A.N.M.; MIKULITS, W.

    2010-01-01

    The development of hepatocellular carcinomas from malignant hepatocytes is frequently associated with intra- and peritumoral accumulation of connective tissue arising from activated hepatic stellate cells. For both tumorigenesis and hepatic fibrogenesis, transforming growth factor (TGF)-β signaling executes key roles and therefore is considered as a hallmark of these pathological events. By employing cellular transplantation we show that the interaction of neoplastic MIM-R hepatocytes with the tumor microenvironment, containing either activated hepatic stellate cells (M1-4HSCs) or myofibroblasts derived thereof (M-HTs), induces progression in malignancy. Cotransplantation of MIM-R hepatocytes with M-HTs yielded strongest MIM-R generated tumor formation accompanied by nuclear localization of Smad2/3 as well as of β-catenin. Genetic interference with TGF-β signaling by gain of antagonistic Smad7 in MIM-R hepatocytes diminished epithelial dedifferentiation and tumor progression upon interaction with M1-4HSCs or M-HTs. Further analysis showed that tumors harboring disrupted Smad signaling are devoid of nuclear β-catenin accumulation, indicating a crosstalk between TGF-β and β-catenin signaling. Together, these data demonstrate that activated HSCs and myofibroblasts directly govern hepatocarcinogenesis in a TGF-β dependent fashion by inducing autocrine TGF-β signaling and nuclear β-catenin accumulation in neoplastic hepatocytes. These results indicate that intervention with TGF-β signaling is highly promising in liver cancer therapy. PMID:16883581

  19. Biogenesis of the rat hepatocyte plasma membrane in vivo: comparison of the pathways taken by apical and basolateral proteins using subcellular fractionation

    International Nuclear Information System (INIS)

    Bartles, J.R.; Feracci, H.M.; Stieger, B.; Hubbard, A.L.

    1987-01-01

    We have used pulse-chase metabolic radiolabeling with L-[ 35 S]methionine in conjunction with subcellular fractionation and specific protein immunoprecipitation techniques to compare the posttranslational transport pathways taken by endogenous domain-specific integral proteins of the rat hepatocyte plasma membrane in vivo. Our results suggest that both apical (HA 4, dipeptidylpeptidase IV, and aminopeptidase N) and basolateral (CE 9 and the asialoglycoprotein receptor [ASGP-R]) proteins reach the hepatocyte plasma membrane with similar kinetics. The mature molecular mass form of each of these proteins reaches its maximum specific radioactivity in a purified hepatocyte plasma membrane fraction after only 45 min of chase. However, at this time, the mature radiolabeled apical proteins are not associated with vesicles derived from the apical domain of the hepatocyte plasma membrane, but instead are associated with vesicles which, by several criteria, appear to be basolateral plasma membrane. These vesicles: (a) fractionate like basolateral plasma membrane in sucrose density gradients and in free-flow electrophoresis; (b) can be separated from the bulk of the likely organellar contaminants, including membranes derived from the late Golgi cisternae, transtubular network, and endosomes; (c) contain the proven basolateral constituents CE 9 and the ASGP-R, as judged by vesicle immunoadsorption using fixed Staphylococcus aureus cells and anti-ASGP-R antibodies; and (d) are oriented with their ectoplasmic surfaces facing outward, based on the results of vesicle immunoadsorption experiments using antibodies specific for the ectoplasmic domain of the ASGP-R. Only at times of chase greater than 45 min do significant amounts of the mature radiolabeled apical proteins arrive at the apical domain, and they do so at different rates

  20. Stiffness of hyaluronic acid gels containing liver extracellular matrix supports human hepatocyte function and alters cell morphology.

    Science.gov (United States)

    Deegan, Daniel B; Zimmerman, Cynthia; Skardal, Aleksander; Atala, Anthony; Shupe, Thomas D

    2015-03-01

    Tissue engineering and cell based liver therapies have utilized primary hepatocytes with limited success due to the failure of hepatocytes to maintain their phenotype in vitro. In order to overcome this challenge, hyaluronic acid (HA) cell culture substrates were formulated to closely mimic the composition and stiffness of the normal liver cellular microenvironment. The stiffness of the substrate was modulated by adjusting HA hydrogel crosslinking. Additionally, the repertoire of bioactive molecules within the HA substrate was bolstered by supplementation with normal liver extracellular matrix (ECM). Primary human hepatocyte viability and phenotype were determined over a narrow physiologically relevant range of substrate stiffnesses from 600 to 4600Pa in both the presence and absence of liver ECM. Cell attachment, viability, and organization of the actin cytoskeleton improved with increased stiffness up to 4600Pa. These differences were not evident in earlier time points or substrates containing only HA. However, gene expression for the hepatocyte markers hepatocyte nuclear factor 4 alpha (HNF4α) and albumin significantly decreased on the 4600Pa stiffness at day 7 indicating that cells may not have maintained their phenotype long-term at this stiffness. Function, as measured by albumin secretion, varied with both stiffness and time in culture and peaked at day 7 at the 1200Pa stiffness, slightly below the stiffness of normal liver ECM at 3000Pa. Overall, gel stiffness affected primary human hepatocyte cell adhesion, functional marker expression, and morphological characteristics dependent on both the presence of liver ECM in gel substrates and time in culture. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Evaluating the uptake and intracellular fate of polystyrene nanoparticles by primary and hepatocyte cell lines in vitro

    International Nuclear Information System (INIS)

    Johnston, Helinor J.; Semmler-Behnke, Manuela; Brown, David M.; Kreyling, Wolfgang; Tran, Lang; Stone, Vicki

    2010-01-01

    Nanoparticles (NPs) are being used within diverse applications such as medicines, clothing, cosmetics and food. In order to promote the safe development of such nanotechnologies it is essential to assess the potential adverse health consequences associated with human exposure. The liver is recognised as a target site for NP toxicity, due to NP accumulation within this organ subsequent to injection, inhalation or instillation. The uptake of fluorescent polystyrene carboxylated particles (20 nm or 200 nm diameter) by hepatocytes was determined using confocal microscopy; with cells imaged 'live' during particle exposure or after exposure within fixed cells. Comparisons between the uptake of polystyrene particles by primary rat hepatocytes, and human hepatocyte cell lines (C3A and HepG2) were made. Uptake of particles by hepatocytes was size, time, and serum dependent. Specifically, the uptake of 200 nm particles was limited, but 20 nm NPs were internalised by all cell types from 10 min onwards. At 10 min, 20 nm NP fluorescence co-localised with the tubulin cytoskeleton staining; after 30 min NP fluorescence compartmentalised into structures located within and/or between cells. The fate of internalised NPs was considered and they were not contained within early endosomes or lysosomes, but within mitochondria of cell lines. NPs accumulated within bile canaliculi to a limited extent, which suggests that NPs can be eliminated within bile. This is in keeping with the finding that gold NPs were eliminated in bile following intravenous injection into rats. The findings were, in the main, comparable between primary rat hepatocytes and the different human hepatocyte cell lines.

  2. Influence of flow conditions and matrix coatings on growth and differentiation of three-dimensionally cultured rat hepatocytes.

    Science.gov (United States)

    Fiegel, Henning C; Havers, Joerg; Kneser, Ulrich; Smith, Molly K; Moeller, Tim; Kluth, Dietrich; Mooney, David J; Rogiers, Xavier; Kaufmann, Peter M

    2004-01-01

    Maintenance of liver-specific function of hepatocytes in culture is still difficult. Improved culture conditions may enhance the cell growth and function of cultured cells. We investigated the effect of three-dimensional culture under flow conditions, and the influence of surface modifications in hepatocyte cultures. Hepatocytes were harvested from Lewis rats. Cells were cultured on three-dimensional polymeric poly-lactic-co-glycolic acid (PLGA) matrices in static culture, or in a pulsatile flow-bioreactor system. Different surface modifications of matrices were investigated: coating with collagen I, collagen IV, laminin, or fibronectin; or uncoated matrix. Hepatocyte numbers, DNA content, and albumin secretion rate were assessed over the observation period. Culture under flow condition significantly enhanced cell numbers. An additional improvement of this effect was observed, when matrix coating was used. Cellular function also showed a significant increase (4- to 5-fold) under flow conditions when compared with static culture. Our data showed that culture under flow conditions improves cell number, and strongly enhances cellular function. Matrix modification by coating with extracellular matrix showed overall an additive stimulatory effect. Our conclusion is that combining three-dimensional culture under flow conditions and using matrix modification significantly improves culture conditions and is therefore attractive for the development of successful culture systems for hepatocytes.

  3. The Hepatitis B Virus (HBV) HBx Protein Activates AKT To Simultaneously Regulate HBV Replication and Hepatocyte Survival

    Science.gov (United States)

    Rawat, Siddhartha

    2014-01-01

    ABSTRACT Chronic infection with hepatitis B virus (HBV) is a risk factor for developing liver diseases such as hepatocellular carcinoma (HCC). HBx is a multifunctional protein encoded by the HBV genome; HBx stimulates HBV replication and is thought to play an important role in the development of HBV-associated HCC. HBx can activate the phosphatidylinositol 3-kinase (PI3K)/AKT signaling pathway in some cell lines; however, whether HBx regulates PI3K/AKT signaling in normal hepatocytes has not been evaluated. In studies described here, we assessed HBx activation of PI3K/AKT signaling in an ex vivo model of cultured primary hepatocytes and determined how this HBx activity affects HBV replication. We report that HBx activates AKT in primary hepatocytes and that the activation of AKT decreases HBV replication and HBV mRNA and core protein levels. We show that the transcription factor hepatocyte nuclear factor 4α (HNF4α) is a target of HBx-regulated AKT, and we link HNF4α to HBx-regulated AKT modulation of HBV transcription and replication. Although we and others have shown that HBx stimulates and is likely required for HBV replication, we now report that HBx also activates signals that can diminish the overall level of HBV replication. While this may seem counterintuitive, we show that an important effect of HBx activation of AKT is inhibition of apoptosis. Consequently, our studies suggest that HBx balances HBV replication and cell survival by stimulating signaling pathways that enhance hepatocyte survival at the expense of higher levels of HBV replication. IMPORTANCE Chronic hepatitis B virus (HBV) infection is a common cause of the development of liver cancer. Regulation of cell signaling pathways by the HBV HBx protein is thought to influence the development of HBV-associated liver cancer. HBx stimulates, and may be essential for, HBV replication. We show that HBx activates AKT in hepatocytes to reduce HBV replication. While this seems contradictory to an

  4. Calculation of the hyperfine interaction using an effective-operator form of many-body theory

    International Nuclear Information System (INIS)

    Garpman, S.; Lindgren, I.; Lindgren, J.; Morrison, J.

    1975-01-01

    The effective-operator form of many-body theory is reviewed and applied to the calculation of the hyperfine structure. Numerical results are given for the 2p, 3p, and 4p excited states of Li and the 3p state of Na. This is the first complete calculation of the hyperfine structure using an effective-operator form of perturbation theory. As in the Brueckner-Goldstone form of many-body theory, the various terms in the perturbation expansion are represented by Feynman diagrams which correspond to basic physical processes. The angular part of the perturbation diagrams are evaluated by taking advantage of the formal analogy between the Feynman diagrams and the angular-momentum diagrams, introduced by Jucys et al. The radial part of the diagrams is calculated by solving one- and two-particle equations for the particular linear combination of excited states that contribute to the Feynman diagrams. In this way all second- and third-order effects are accurately evaluated without explicitly constructing the excited orbitals. For the 2p state of Li our results are in agreement with the calculations of Nesbet and of Hameed and Foley. However, our quadrupole calculation disagrees with the work of Das and co-workers. The many-body results for Li and Na are compared with semiempirical methods for evaluating the quadrupole moment from the hyperfine interaction, and a new quadrupole moment of 23 Na is given

  5. A transgenic rat hepatocyte - Kupffer cell co-culture model for evaluation of direct and macrophage-related effect of poly(amidoamine) dendrimers.

    Science.gov (United States)

    Jemnitz, Katalin; Bátai-Konczos, Attila; Szabó, Mónika; Ioja, Enikő; Kolacsek, Orsolya; Orbán, Tamás I; Török, György; Homolya, László; Kovács, Eszter; Jablonkai, István; Veres, Zsuzsa

    2017-02-01

    Increasing number of papers demonstrate that Kupffer cells (KCs) play a role in the development of drug induced liver injury (DILI). Furthermore, elevated intracellular Ca 2+ level of hepatocytes is considered as a common marker of DILI. Here we applied an in vitro model based on hepatocyte mono- and hepatocyte/KC co-cultures (H/KC) isolated from transgenic rats stably expressing the GCaMP2 fluorescent Ca 2+ sensor protein to investigate the effects of polycationic (G5), polyanionic (G4.5) and polyethylene-glycol coated neutral (G5 Peg) dendrimers known to accumulate in the liver, primarily in KCs. Following dendrimer exposure, hepatocyte homeostasis was measured by MTT cytotoxicity assay and by Ca 2+ imaging, while hepatocyte functions were studied by CYP2B1/2 inducibility, and bilirubin and taurocholate transport. G5 was significantly more cytotoxic than G4.5 for hepatocytes and induced Ca 2+ oscillation and sustained Ca 2+ signals at 1μM and10 μM, respectively both in hepatocytes and KCs. Dendrimer-induced Ca 2+ signals in hepatocytes were attenuated by macrophages. Activation of KCs by lipopolysaccharide and G5 decreased the inducibility of CYP2B1/2, which was restored by depleting the KCs with gadolinium-chloride and pentoxyphylline, suggesting a role of macrophages in the hindrance of CYP2B1/2 induction by G5 and lipopolysaccharide. In the H/KC, but not in the hepatocyte mono-culture, G5 reduced the canalicular efflux of bilirubin and stimulated the uptake and canalicular efflux of taurocholate. In conclusion, H/KC provides a good model for the prediction of hepatotoxic potential of drugs, especially of nanomaterials known to be trapped by macrophages, activation of which presumably contributes to DILI. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. 3D-printed gelatin scaffolds of differing pore geometry modulate hepatocyte function and gene expression.

    Science.gov (United States)

    Lewis, Phillip L; Green, Richard M; Shah, Ramille N

    2018-03-15

    Three dimensional (3D) printing is highly amenable to the fabrication of tissue-engineered organs of a repetitive microstructure such as the liver. The creation of uniform and geometrically repetitive tissue scaffolds can also allow for the control over cellular aggregation and nutrient diffusion. However, the effect of differing geometries, while controlling for pore size, has yet to be investigated in the context of hepatocyte function. In this study, we show the ability to precisely control pore geometry of 3D-printed gelatin scaffolds. An undifferentiated hepatocyte cell line (HUH7) demonstrated high viability and proliferation when seeded on 3D-printed scaffolds of two different geometries. However, hepatocyte specific functions (albumin secretion, CYP activity, and bile transport) increases in more interconnected 3D-printed gelatin cultures compared to a less interconnected geometry and to 2D controls. Additionally, we also illustrate the disparity between gene expression and protein function in simple 2D culture modes, and that recreation of a physiologically mimetic 3D environment is necessary to induce both expression and function of cultured hepatocytes. Three dimensional (3D) printing provides tissue engineers the ability spatially pattern cells and materials in precise geometries, however the biological effects of scaffold geometry on soft tissues such as the liver have not been rigorously investigated. In this manuscript, we describe a method to 3D print gelatin into well-defined repetitive geometries that show clear differences in biological effects on seeded hepatocytes. We show that a relatively simple and widely used biomaterial, such as gelatin, can significantly modulate biological processes when fabricated into specific 3D geometries. Furthermore, this study expands upon past research into hepatocyte aggregation by demonstrating how it can be manipulated to enhance protein function, and how function and expression may not precisely correlate in

  7. R-spondin3-LGR4 signaling protects hepatocytes against DMOG-induced hypoxia/reoxygenation injury through activating β-catenin.

    Science.gov (United States)

    Liu, Shiying; Yin, Yue; Yu, Ruili; Li, Yin; Zhang, Weizhen

    2018-04-30

    Leucine-rich repeat G-protein-coupled receptor 4 (LGR4) and its ligands R-spondin1-4 (Rspos) have been vastly investigated in embryonic development. The biological functions of Rspos-LGR4 system in liver remains largely unknown. Here, we explored whether it protects hepatocytes against hypoxia/reoxygenation (H/R) induced damage. H/R injury was induced by dimethyloxalylglycine (DMOG) in AML12 cells and the effects of Rspo3 on cell proliferation and apoptosis were assessed. Specific shRNAs were used to interfere LGR4 or β-catenin. DMOG caused hepatocytes damage evidenced by increase in HIF-1α, cell death and apoptosis genes p27 and Bax, with concurrent decrease of cell proliferation genes PCNA and CyclinD1. Of all the Rspos, Rspo3 is predominantly expressed in AML12 hepatocytes. Importantly, Rspo3 demonstrated an alteration in a manner similar to proliferation-related genes during H/R injury. Rspo3 pretreatment rendered hepatocytes less vulnerable to DMOG induced H/R injury. Ablation of LGR4 using shRNA attenuated the protective effects of Rspo3. Wnt3a also protected AML12 cells from damages caused by H/R, showing enhanced proliferation activity. Notably, knockdown of β-catenin in hepatocytes completely abolished the effect of Rspo3 pretreatment on the expression levels of PCNA and CyclinD1. Rspo3-LGR4 axis protects hepatocytes from H/R injury via activating β-catenin. Copyright © 2018. Published by Elsevier Inc.

  8. A survey of consumer attitudes to the supply and use of human hepatocytes in the United Kingdom.

    Science.gov (United States)

    Lloyd, Tom D R; Orr, Samantha; Dennison, Ashley R

    2003-11-01

    Human hepatocytes are the model of choice for pharmacotoxicological studies, but their acquisition is often problematic due to ethical and logistical difficulties. The UK Human Tissue Bank is a not-for-profit organisation that acquires and processes human tissue, with a specialist interest in the isolation of human hepatocytes. A recent in-house survey of the processing of liver tissue over 1 year revealed that freshly isolated hepatocytes were underutilised due to mismatched consumer demand, despite the published need for them. We present the results of a telephone survey to investigate the reasons behind this paradox. This survey highlighted some problem areas, including "out of hours" availability of cells and personnel difficulties, but overall, demonstrated the value of such a service, with numerous researchers taking advantage of available good quality human hepatocytes. Although further work is required in optimising long-term storage protocols through cryopreservation, we have demonstrated that tissue handling of this type can be successful and beneficial to the pharmaceutical and biotechnology industries.

  9. Interleukin-1 inhibition facilitates recovery from liver injury and promotes regeneration of hepatocytes in alcoholic hepatitis in mice.

    Science.gov (United States)

    Iracheta-Vellve, Arvin; Petrasek, Jan; Gyogyosi, Benedek; Bala, Shashi; Csak, Timea; Kodys, Karen; Szabo, Gyongyi

    2017-07-01

    Inflammation and impaired hepatocyte regeneration contribute to liver failure in alcoholic hepatitis (AH). Interleukin (IL)-1 is a key inflammatory cytokine in the pathobiology of AH. The role of IL-1 in liver regeneration in the recovery phase of alcohol-induced liver injury is unknown. In this study, we tested IL-1 receptor antagonist to block IL-1 signalling in a mouse model of acute-on-chronic liver injury on liver inflammation and hepatocyte regeneration in AH. We observed that inhibition of IL-1 signalling decreased liver inflammation and neutrophil infiltration, and resulted in enhanced regeneration of hepatocytes and increased rate of recovery from liver injury in AH. Our novel findings suggest that IL-1 drives sustained liver inflammation and impaired hepatocyte regeneration even after cessation of ethanol exposure. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. Genetic background effects of keratin 8 and 18 in a DDC-induced hepatotoxicity and Mallory-Denk body formation mouse model.

    Science.gov (United States)

    Haybaeck, Johannes; Stumptner, Cornelia; Thueringer, Andrea; Kolbe, Thomas; Magin, Thomas M; Hesse, Michael; Fickert, Peter; Tsybrovskyy, Oleksiy; Müller, Heimo; Trauner, Michael; Zatloukal, Kurt; Denk, Helmut

    2012-06-01

    Keratin 8 (K8) and keratin 18 (K18) form the major hepatocyte cytoskeleton. We investigated the impact of genetic loss of either K8 or K18 on liver homeostasis under toxic stress with the hypothesis that K8 and K18 exert different functions. krt8⁻/⁻ and krt18⁻/⁻ mice crossed into the same 129-ola genetic background were treated by acute and chronic administration of 3,5-diethoxy-carbonyl-1,4-dihydrocollidine (DDC). In acutely DDC-intoxicated mice, macrovesicular steatosis was more pronounced in krt8⁻/⁻ and krt18⁻/⁻ compared with wild-type (wt) animals. Mallory-Denk bodies (MDBs) appeared in krt18⁻/⁻ mice already at an early stage of intoxication in contrast to krt8⁻/⁻ mice that did not display MDB formation when fed with DDC. Keratin-deficient mice displayed significantly lower numbers of apoptotic hepatocytes than wt animals. krt8⁻/⁻, krt18⁻/⁻ and control mice displayed comparable cell proliferation rates. Chronically DDC-intoxicated krt18⁻/⁻ and wt mice showed a similarly increased degree of steatohepatitis with hepatocyte ballooning and MDB formation. In krt8⁻/⁻ mice, steatosis was less, ballooning, and MDBs were absent. krt18⁻/⁻ mice developed MDBs whereas krt8⁻/⁻ mice on the same genetic background did not, highlighting the significance of different structural properties of keratins. They are independent of the genetic background as an intrinsic factor. By contrast, toxicity effects may depend on the genetic background. krt8⁻/⁻ and krt18⁻/⁻ mice on the same genetic background show similar sensitivity to DDC intoxication and almost resemble wt animals regarding survival, degree of porphyria, liver-to-body weight ratio, serum bilirubin and liver enzyme levels. This stands in contrast to previous work where krt8⁻/⁻ and krt18⁻/⁻ mice on different genetic backgrounds were investigated.

  11. Appropriateness to set a group health‐based guidance value for fumonisins and their modified forms

    DEFF Research Database (Denmark)

    Petersen, Annette

    2018-01-01

    The EFSA Panel on Contaminants in the Food Chain (CONTAM) established a tolerable daily intake (TDI) for fumonisin B1 (FB1) of 1.0 μg/kg body weight (bw) per day based on increased incidence of megalocytic hepatocytes found in a chronic study with mice. The CONTAM Panel considered the limited data...

  12. Hepatic iron overload is associated with hepatocyte apoptosis during Clonorchis sinensis infection.

    Science.gov (United States)

    Han, Su; Tang, Qiaoran; Chen, Rui; Li, Yihong; Shu, Jing; Zhang, Xiaoli

    2017-08-01

    Hepatic iron overload has been implicated in many liver diseases; however, whether it is involved in clonorchiasis remains unknown. The purpose of this study is to investigate whether Clonorchis sinensis (C. sinensis) infection causes hepatic iron overload, analyze the relationship between the iron overload and associated cell apoptosis, so as to determine the role of excess iron plays in C. sinensis-induced liver injury. The Perls' Prussian staining and atomic absorption spectrometry methods were used to investigate the iron overload in hepatic sections of wistar rats and patients infected with C. sinensis. The hepatic apoptosis was detected by transferase uridyl nick end labeling (TUNEL) methods. Spearman analysis was used for determining the correlation of the histological hepatic iron index and the apoptotic index. Blue iron particles were deposited mainly in the hepatocytes, Kupffer cells and endothelial cells, around the liver portal and central vein area of both patients and rats. The total iron score was found to be higher in the infected groups than the respective control from 8 weeks. The hepatic iron concentration was also significantly higher in treatment groups than in control rats from 8 weeks. The hepatocyte apoptosis was found to be significantly higher in the portal area of the liver tissue and around the central vein. However, spearman's rank correlation coefficient revealed that there was a mildly negative correlation between the iron index and hepatocyte apoptosis. This present study confirmed that hepatic iron overload was found during C. sinensis infection. This suggests that iron overload may be associated with hepatocyte apoptosis and involved in liver injury during C. sinensis infection. Further studies are needed to investigate the molecular mechanism involved here.

  13. Effect of honokiol on the induction of drug-metabolizing enzymes in human hepatocytes

    Directory of Open Access Journals (Sweden)

    Cho YY

    2014-11-01

    Full Text Available Yong-Yeon Cho,1 Hyeon-Uk Jeong,1 Jeong-Han Kim,2 Hye Suk Lee1 1College of Pharmacy, The Catholic University of Korea, Bucheon, Korea; 2Department of Agricultural Biotechnology, Seoul National University, Seoul, Korea Abstract: Honokiol, 2-(4-hydroxy-3-prop-2-enyl-phenyl-4-prop-2-enyl-phenol, an active component of Magnolia officinalis and Magnolia grandiflora, exerts various pharmacological activities such as antitumorigenic, antioxidative, anti-inflammatory, neurotrophic, and antithrombotic effects. To investigate whether honokiol acts as a perpetrator in drug interactions, messenger ribonucleic acid (mRNA levels of phase I and II drug-metabolizing enzymes, including cytochrome P450 (CYP, UDP-glucuronosyltransferase (UGT, and sulfotransferase 2A1 (SULT2A1, were analyzed by real-time reverse transcription polymerase chain reaction following 48-hour honokiol exposure in three independent cryopreserved human hepatocyte cultures. Honokiol treatment at the highest concentration tested (50 µM increased the CYP2B6 mRNA level and CYP2B6-catalyzed bupropion hydroxylase activity more than two-fold in three different hepatocyte cultures, indicating that honokiol induces CYP2B6 at higher concentrations. However, honokiol treatment (0.5–50 µM did not significantly alter the mRNA levels of phase I enzymes (CYP1A2, CYP3A4, CYP2C8, CYP2C9, and CYP2C19 or phase II enzymes (UGT1A1, UGT1A4, UGT1A9, UGT2B7, and SULT2A1 in cryopreserved human hepatocyte cultures. CYP1A2-catalyzed phenacetin O-deethylase and CYP3A4-catalyzed midazolam 1'-hydroxylase activities were not affected by 48-hour honokiol treatment in cryopreserved human hepatocytes. These results indicate that honokiol is a weak CYP2B6 inducer and is unlikely to increase the metabolism of concomitant CYP2B6 substrates and cause pharmacokinetic-based drug interactions in humans. Keywords: honokiol, human hepatocytes, drug interactions, cytochrome P450, UDP-glucuronosyltransferases

  14. Cholangiocarcinoma in Cirrhosis: Value of Hepatocyte Specific Magnetic Resonance Imaging.

    Science.gov (United States)

    Piscaglia, Fabio; Iavarone, Massimo; Galassi, Marzia; Vavassori, Sara; Renzulli, Matteo; Forzenigo, Laura Virginia; Granito, Alessandro; Salvatore, Veronica; Sangiovanni, Angelo; Golfieri, Rita; Colombo, Massimo; Bolondi, Luigi

    2015-10-01

    The diagnosis of intrahepatic cholangiocellular carcinoma (ICC) remains elusive at imaging, which is a critical issue in cirrhotic patients in whom a diagnosis of hepatocellular carcinoma (HCC) can be established only by imaging. The aim of the study was to evaluate the potential of MRI in the diagnosis of ICC in cirrhosis using 'hepatocyte-specific' Gadolinium (Gd)-based contrast agents. Sixteen histologically proven and retrospectively identified ICCs on cirrhosis were investigated with hepatocyte-specific magnetic resonance contrast agents (6 in Bologna with Gd-EOB-DTPA and 10 in Milan with Gd-BOPTA). The control group consisted of 41 consecutively and prospectively collected nodules (31 HCCs) imaged with Gd-EOB-DTPA. Fifteen ICC nodules (94%) displayed hypointensity in the hepatobiliary phase, suggesting malignancy. Thirteen cholangiocarcinomas (81%) showed hyperenhancement in the venous phase. Only 2 cholangiocarcinoma nodules showed hypoenhancement in the venous phase, corresponding to washout, in both cases preceded by rim enhancement in arterial phase. All the hepatocarcinomas showed hypointensity in hepatobiliary phase, but was always preceded by hypointensity in the venous phase; arterial rim enhancement was never observed in any hepatocarcinoma or regenerative nodule. MRI with hepatocyte-specific Gd-based contrast agents showed a pattern of malignancy in almost all the ICCs, concurrently avoiding misdiagnosis with hepatocarcinoma. These findings suggest a greater diagnostic capacity for this technique compared with the results of MRI with conventional contrast agents reported in the literature in this setting. © 2015 S. Karger AG, Basel.

  15. Developing a New Two-Step Protocol to Generate Functional Hepatocytes from Wharton’s Jelly-Derived Mesenchymal Stem Cells under Hypoxic Condition

    Directory of Open Access Journals (Sweden)

    Patcharee Prasajak

    2013-01-01

    Full Text Available The shortage of donor livers and hepatocytes is a major limitation of liver transplantation. Thus, generation of hepatocyte-like cells may provide alternative choice for therapeutic applications. In this study, we developed a new method to establish hepatocytes from Wharton’s jelly-derived mesenchymal stem cells (WJ-MSCs cell lines named WJMSCs-SUT1 and WJMSCs-SUT2 under hypoxic condition. This new method could rapidly drive both WJ-MSCs cell lines into hepatic lineage within 18 days. The achievement of hepatogenic differentiation was confirmed by the characterization of both phenotypes and functions. More than 80% MSCs-derived hepatocyte-like cells (MSCDHCs achieved functional hepatocytes including hepatic marker expressions both at gene and protein levels, glycogen storage, low-density lipoprotein uptake, urea production, and albumin secretion. This study highlights the establishment of new hepatogenic induction protocol under hypoxic condition in order to mimic hypoxic microenvironment in typical cell physiology. In conclusion, we present a simple, high-efficiency, and time saving protocol for the generation of functional hepatocyte-like cells from WJ-MSCs in hypoxic condition. The achievement of this method may overcome the limitation of donor hepatocytes and provides a new avenue for therapeutic value in cell-based therapy for life-threatening liver diseases, regenerative medicine, toxicity testing for pharmacological drug screening, and other medical related applications.

  16. MCD-induced steatohepatitis is associated with hepatic adiponectin resistance and adipogenic transformation of hepatocytes.

    Science.gov (United States)

    Larter, Claire Z; Yeh, Matthew M; Williams, Jacqueline; Bell-Anderson, Kim S; Farrell, Geoffrey C

    2008-09-01

    In these studies, we tested the hypothesis that increased lipid intake would exacerbate the severity of nutritional steatohepatitis. C57Bl/6J mice were fed methionine-and-choline deficient (MCD) diets containing 20% (high) or 5% (low) fat by weight for 3 weeks and compared to lipid-matched controls. MCD feeding increased serum ALT levels and induced hepatic steatosis, lobular inflammation and ballooning degeneration of hepatocytes, irrespective of dietary fat content. Hepatic triglyceride accumulation was similar between high and low-fat MCD-fed mice, but lipoperoxide levels were approximately 3-fold higher in the high-fat MCD-fed animals. Serum adiponectin levels increased in MCD-fed mice, although to a lesser extent in high-fat fed animals. AMPK phosphorylation was correspondingly increased in muscle of MCD-fed mice, but hepatic AMPK phosphorylation decreased, and there was little evidence of PPAR alpha activation, suggesting impaired adiponectin action in the livers of MCD-fed animals. Hepatocyte PPAR gamma mRNA levels increased in MCD-fed mice, and were associated with increased aP2 expression, indicating adipogenic transformation of hepatocytes. Increased dietary lipid intake did not alter steatohepatitis severity in MCD-fed mice despite increased lipoperoxide accumulation. Instead, steatohepatitis was associated with impaired hepatic adiponectin action, and adipogenic transformation of hepatocytes in both low and high-fat MCD-fed mice.

  17. Modulation of protein synthesis and secretion by substratum in primary cultures of rat hepatocytes

    International Nuclear Information System (INIS)

    Sudhakaran, P.R.; Stamatoglou, S.C.; Hughes, R.C.

    1986-01-01

    Hepatocytes isolated by perfusion of adult rat liver and cultured on substrata consisting of one or more of the major components of the liver biomatrix (fibronectin, laminin, type IV collagen) have been examined for the synthesis of defined proteins. Under these conditions, tyrosine amino transferase, a marker of hepatocyte function, is maintained at similar levels in response to dexamethasone over 5 days in culture on each substratum, and total cellular protein synthesis remains constant. By contrast, there is a rapid decrease in synthesis and secretion of albumin and a 3-7-fold increase in synthesis and section of α-fetoprotein which are most marked on a laminin substratum, but least evident on type IV collagen, and an increased synthesis of fibronectin and type IV collagen. The newly synthesized matrix proteins are present in the cell layer as well as in cell secretions. The enhanced synthesis of fibronectin is less in cells seeded onto a fibronectin substratum than on laminin or type IV collagen substrata. These results indicate that hepatocytes cultured in serum-free medium on substrata composed of components of the liver biomatrix maintain certain functions of the differentiated state (tyrosine amino transferase), lose others (albumin secretion) and switch to increased synthesis of matrix components as well as fetal markers such as α-fetoprotein. The magnitude of these effects depends on the substratum on which the hepatocytes are cultured

  18. Zr O2-Y2 O3 ceramic bodies forming by slip casting

    International Nuclear Information System (INIS)

    Menezes, Cristiane A.B. de; Menezes, Fernanda; Ussui, Valter; Lazar, Dolores R.R.; Paschoal, Jose Otavio A.

    1996-01-01

    Slip casting technique of 3 mol% yttria stabilized zirconia powders suspensions has been used for ceramic bodies forming. The powders were produced by coprecipitation process with ammonium hydroxide in the Zirconium Pilot Plant of IPEN (Institute for Energy and Nuclear Researches, Sao Paulo, SP, (Brazil). Experiments were performed by preparing suspensions of powders with dispersing agents. These suspensions were submitted to milling and casting in plaster molds. After drying and heating at 700 deg C, the obtained specimens were sintered at 1500 deg C for 3 hours. The ceramic bodies were investigated by scanning electron microscopy and X-ray diffraction, and tested in high temperature conditions. (author)

  19. Manganese Transport and Toxicity in Polarized WIF-B Hepatocytes.

    Science.gov (United States)

    Thompson, Khristy J; Hein, Jennifer; Baez, Andrew; Sosa, Jose Carlo; Wessling-Resnick, Marianne

    2018-05-24

    Mn toxicity arises from nutritional problems, community and occupational exposures, and genetic risks. Mn blood levels are controlled by hepatobiliary clearance. The goals of this study were to determine the cellular distribution of Mn transporters in polarized hepatocytes, to establish an in vitro assay for hepatocyte Mn efflux, and to examine possible roles the Mn transporters would play in metal import and export. For these experiments, hepatocytoma WIF-B cells were grown for 12-14 days to achieve maximal polarity. Immunoblots showed that Mn transporters ZIP8, ZnT10, ferroportin (Fpn), and ZIP14 were present. Indirect immunofluorescence microscopy localized Fpn and ZIP14 to WIF-B cell basolateral domains while ZnT10 and ZIP8 associated with intracellular vesicular compartments. ZIP8-positive structures were distributed uniformly throughout the cytoplasm, but ZnT10-positive vesicles were adjacent to apical bile compartments. WIF-B cells were sensitive to Mn toxicity, showing decreased viability after 16 h exposure to > 250 M MnCl2. However, the hepatocytes were resistant to 4 h exposures of up to 500 M MnCl2 despite 50-fold increased Mn content. Washout experiments showed time-dependent efflux with 80% Mn released after a 4 h chase period. Hepcidin reduced levels of Fpn in WIF-B cells, clearing Fpn from the cell surface, but Mn efflux was unaffected. The secretory inhibitor brefeldin A did block release of Mn from WIF-B cells, suggesting vesicle fusion may be involved in export. These results point to a possible role of ZnT10 to import Mn into vesicles that subsequently fuse with the apical membrane and empty their contents into bile.

  20. Ontogenetic changes in the ultrastructure of rat hepatocyte organelles after prenatal x irradiation

    International Nuclear Information System (INIS)

    Chedid, A.; Nair, V.

    1975-01-01

    The effects of prenatal x irradiation on the development of hepatocyte organelles have been studied in Sprague-Dawley rats. Pregnant rats received 50 R to the pelvic region on the 13th gestation day (g.d.). Animals were sacrificed on g.d.'s 15 and 20, day of birth, and 5th postnatal day. The fetal and neonatal livers were obtained and processed for electron-microscopic examination. The most striking discernible change after irradiation involves the appearance of cytoplasmic ''polyribosomal aggregates'' in the hepatocyte specimens of 15th and 20th g.d.'s. In the control rat, smooth endoplasmic reticulum (SER) appears for the first time on 20th g.d., while no SER could be detected in the hepatocytes from the irradiated animals at this period nor on day of birth. In the irradiated animals, SER was observed on the 5th postnatal day. Our results are consistent with the hypothesis that lipid peroxidation membrane alteration, delayed appearance of SER, and ''polyribosomal aggregation'' may be sequentially linked events after prenatal x irradiation. (U.S.)

  1. Knockdown of autophagy enhances innate immune response in hepatitis C virus infected hepatocytes

    Science.gov (United States)

    Shrivastava, Shubham; Raychoudhuri, Amit; Steele, Robert; Ray, Ranjit; Ray, Ratna B.

    2010-01-01

    The role of autophagy in disease pathogenesis following viral infection is beginning to be elucidated. We have previously reported that hepatitis C virus (HCV) infection in hepatocytes induces autophagy. However, the biological significance of HCV induced autophagy has not been clarified. Autophagy has recently been identified as a novel component of innate immune system against viral infection. In the present study, we have shown that knockdown of autophagy related protein Beclin1 or ATG7 in immortalized human hepatocytes (IHH) inhibited HCV growth. Beclin1 or ATG7 knockdown IHH when infected with HCV exhibited an increased expression of IFN-β, OAS-1, IFN-α and IFI27 mRNAs of the interferon signaling pathways as compared to infection of control IHH. Subsequent study demonstrated that HCV infection in autophagy impaired IHH displayed caspase activation, PARP cleavage and apoptotic cell death. Conclusion The disruption of autophagy machinery in HCV infected hepatocytes activated IFN signaling pathway, and induced apoptosis. Together, these results suggest that HCV induced autophagy impairs innate immune response. PMID:21274862

  2. An improved microphotometry system for measurement of cytochrome P-450 in hepatocyte cytoplasm.

    Science.gov (United States)

    Watanabe, J; Kanamura, S

    1991-05-01

    To measure cytochrome P-450 (P-450) content in hepatocyte cytoplasm, we developed a dual monochromator-equipped microphotometry system (KWSP-1). Simultaneous measurements of absorbance at 450 and 490 nm with narrow band width (0.5 nm) and small spot size (2 microns) were accomplished by this system. Corresponding fields in serial sections could be easily and rapidly identified under the Nomarski imaging mode of KWSP-1. Photometric accuracy and repeatability of wavelength setting of KWSP-1 were also satisfactory for measurement of P-450. With this system, it is thus possible to measure the extinction of P-450 from many small measuring areas and to precisely determine P-450 content in the cytoplasm of rat hepatocytes. A microphotometric method was developed using cuvette slides and two serial 10-microns thick sections (mapping method). The intracellular distribution of P-450 in individual hepatocytes could be visualized by the mapping method with KWSP-1. However, this method was not applicable to tissue sections containing hemoglobin larger than 4 microM.

  3. Asymptotic form of three-body (dtμ)+ and (ddμ)+ wave functions

    International Nuclear Information System (INIS)

    Kino, Y.; Shimamura, I.; Armour, E.A.G.; Kamimura, M.

    1996-01-01

    In order to investigate a discrepancy between existing literature values for the normalization constant in the asymptotic form of three-body wave functions for (DTμ) + , we report the results of a new calculation of the normalization constants for this system as well as the related system (DDμ) + . These were obtained by fitting to accurate variational wave functions with special care being taken to describe the long-range behavior. (orig.)

  4. Frequency of micronuclei in hepatocytes following X and fast-neutron irradiations--an analysis by a linear-quadratic model

    International Nuclear Information System (INIS)

    Ono, K.; Nagata, Y.; Akuta, K.; Abe, M.; Ando, K.; Koike, S.

    1990-01-01

    The usefulness of the micronucleus assay for investigating the radiation response of hepatocytes was examined. The frequency was defined as the ratio of the total number of micronuclei to the number of hepatocytes examined. The dose-response curves were curvilinear after X rays and linear after neutrons. These dose-response curves were analyzed by a linear-quadratic model, frequency = aD + bD2 + c. The a/b ratio was 3.03 +/- 1.26 Gy following X irradiation. This value is within the range of the alpha/beta ratios reported by others using the clonogenic assay of hepatocytes. While the a/b value for neutrons was 24.3 +/- 11.7 Gy, the maximum relative biological effectiveness of neutrons was 6.30 +/- 2.53. Since the micronucleus assay is simple and rapid, it may be a good tool for evaluating the radiation response of hepatocytes in vivo

  5. Acetic acid activates the AMP-activated protein kinase signaling pathway to regulate lipid metabolism in bovine hepatocytes.

    Directory of Open Access Journals (Sweden)

    Xinwei Li

    Full Text Available The effect of acetic acid on hepatic lipid metabolism in ruminants differs significantly from that in monogastric animals. Therefore, the aim of this study was to investigate the regulation mechanism of acetic acid on the hepatic lipid metabolism in dairy cows. The AMP-activated protein kinase (AMPK signaling pathway plays a key role in regulating hepatic lipid metabolism. In vitro, bovine hepatocytes were cultured and treated with different concentrations of sodium acetate (neutralized acetic acid and BML-275 (an AMPKα inhibitor. Acetic acid consumed a large amount of ATP, resulting in an increase in AMPKα phosphorylation. The increase in AMPKα phosphorylation increased the expression and transcriptional activity of peroxisome proliferator-activated receptor α, which upregulated the expression of lipid oxidation genes, thereby increasing lipid oxidation in bovine hepatocytes. Furthermore, elevated AMPKα phosphorylation reduced the expression and transcriptional activity of the sterol regulatory element-binding protein 1c and the carbohydrate responsive element-binding protein, which reduced the expression of lipogenic genes, thereby decreasing lipid biosynthesis in bovine hepatocytes. In addition, activated AMPKα inhibited the activity of acetyl-CoA carboxylase. Consequently, the triglyceride content in the acetate-treated hepatocytes was significantly decreased. These results indicate that acetic acid activates the AMPKα signaling pathway to increase lipid oxidation and decrease lipid synthesis in bovine hepatocytes, thereby reducing liver fat accumulation in dairy cows.

  6. Morphological and Functional Analysis of Hepatocyte Spheroids Generated on Poly-HEMA-Treated Surfaces under the Influence of Fetal Calf Serum and Nonparenchymal Cells

    Directory of Open Access Journals (Sweden)

    Augustinus Bader

    2013-03-01

    Full Text Available Poly (2-hydroxyethyl methacrylate (HEMA has been used as a clinical material, in the form of a soft hydrogel, for various surgical procedures, including endovascular surgery of liver. It is a clear liquid compound and, as a soft, flexible, water-absorbing material, has been used to make soft contact lenses from small, concave, spinning molds. Primary rat hepatocyte spheroids were created on a poly-HEMA-coated surface with the intention of inducing hepatic tissue formation and improving liver functions. We investigated spheroid formation of primary adult rat hepatocyte cells and characterized hepatic-specific functions under the special influence of fetal calf serum (FCS and nonparencymal cells (NPC up to six days in different culture systems (e.g., hepatocytes + FCS, hepatocytes – FCS, NPC + FCS, NPC – FCS, co-culture + FCS, co-culture – FCS in both the spheroid model and sandwich model. Immunohistologically, we detected gap junctions, Ito cell/Kupffer cells, sinusoidal endothelial cells and an extracellular matrix in the spheroid model. FCS has no positive effect in the sandwich model, but has a negative effect in the spheroid model on albumin production, and no influence in urea production in either model. We found more cell viability in smaller diameter spheroids than larger ones by using the apoptosis test. Furthermore, there is no positive influence of the serum or NPC on spheroid formation, suggesting that it may only depend on the physical condition of the culture system. Since the sandwich culture has been considered a “gold standard” in vitro culture model, the hepatocyte spheroids generated on the poly-HEMA-coated surface were compared with those in the sandwich model. Major liver-specific functions, such as albumin secretion and urea synthesis, were evaluated in both the spheroid and sandwich model. The synthesis performance in the spheroid compared to the sandwich culture increases approximately by a factor of 1

  7. Metformin protects primary rat hepatocytes against oxidative stress-induced apoptosis

    NARCIS (Netherlands)

    Conde de la Rosa, Laura; Vrenken, Titia E; Buist-Homan, Manon; Faber, Klaas Nico; Moshage, Han

    The majority of chronic liver diseases are accompanied by oxidative stress, which induces apoptosis in hepatocytes and liver injury. Recent studies suggest that oxidative stress and insulin resistance are important in the pathogenesis of nonalcoholic fatty liver disease (NAFLD) and the

  8. Hepatocyte heterogeneity in the metabolism of amino acids and ammonia

    NARCIS (Netherlands)

    Häussinger, D.; Lamers, W. H.; Moorman, A. F.

    1992-01-01

    With respect to hepatocyte heterogeneity in ammonia and amino acid metabolism, two different patterns of sublobular gene expression are distinguished: 'gradient-type' and 'strict- or compartment-type' zonation. An example for strict-type zonation is the reciprocal distribution of carbamoylphosphate

  9. Choline or methionine reverses impaired secretion of VLDL by hepatocytes from choline-deficient rats

    International Nuclear Information System (INIS)

    Yao, Z.; Vance, D.E.

    1987-01-01

    Male rats fed a choline-deficient (CD) diet for three days accumulated triacylglycerol (TG) in the liver. Hepatocytes from these rats were cultured and maintained in a medium + choline. The rate of secretion of TG was reduced by 50% in the CD cells. Correspondingly, [ 3 H]oleate and [ 3 H]glycerol were incorporated at a 2-fold higher rate into TG secreted by choline-supplemented cells compared to CD cells. Isolation of lipoprotein fractions by ultracentrifugation showed that the reduced secretion of TG by CD hepatocytes was mainly due to an impaired secretion of very low density lipoprotein (VLDL). Incorporation of [ 3 H]leucine into secreted apoB/sub H/, apoB/sub L/ and apoE was markedly reduced in CD cells compared to choline-supplemented cells. Secretion of high density lipoprotein was not reduced in the CD hepatocytes. Normal secretion of VLDL was resumed upon addition of methionine to the CD cells

  10. Effects of carbon tetrachloride on oxidative stress, inflammatory response and hepatocyte apoptosis in common carp (Cyprinus carpio)

    International Nuclear Information System (INIS)

    Jia, Rui; Cao, Li-Ping; Du, Jin-Liang; Wang, Jia-Hao; Liu, Ying-Juan; Jeney, Galina; Xu, Pao; Yin, Guo-Jun

    2014-01-01

    Highlights: • We explored the underlying toxicology of CCl 4 at the cellular and molecular levels. • QRT-PCR detected the gene expression of NF-κB and inflammatory cytokines. • The apoptosis and necrosis occurred simultaneously in carp liver damage. • CCl 4 activated the TNF-α/NF-κB and TRL4/NF-κB signaling pathways. - Abstract: In the present study, the cellular and molecular mechanism of carbon tetrachloride (CCl 4 )-induced hepatotoxicity in fish was investigated by studying the effects of CCl 4 on the oxidative stress, inflammatory response and hepatocyte apoptosis. Common carp were given an intraperitoneal injection of 30% CCl 4 in arachis oil (0.5 ml/kg body weight). At 72 h post-injection, blood were collected to measure glutamate pyruvate transaminase (GPT), glutamate oxalate transaminase (GOT), superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), glutathione (GSH), total antioxidant capacity (T-AOC) and malondialdehyde (MDA), liver samples were taken to analyze toll-like receptor 4 (TLR4), cytochrome P450 2E1 (CYP2E1) and gene expressions of inflammatory cytokines and nuclear factor-κB (NF-κB/cREL). Cell viability and apoptosis were analyzed after treatment of the primary hepatocytes with CCl 4 at 8 mM. The results showed that CCl 4 significantly increased the levels of GPT, GOT, MDA, TLR4 and CYP2E1, reduced the levels of SOD, GPx, CAT, GSH and T-AOC, and up-regulated the gene expressions of NF-κB/cREL and inflammatory cytokines including tumor necrosis factor-α (TNF-α), inducible nitric oxide synthase (iNOS), IL-1β, IL-6 and IL-12. In vitro, CCl 4 caused a dramatic loss in cell viability and induced hepatocyte apoptosis. Overall results suggest that oxidative stress lipid peroxidation, and TNF-α/NF-κB and TRL4/NF-κB signaling pathways play important roles in CCl 4 -induced hepatotoxicity in fish

  11. Effects of carbon tetrachloride on oxidative stress, inflammatory response and hepatocyte apoptosis in common carp (Cyprinus carpio)

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Rui [Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081 (China); Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081 (China); Cao, Li-Ping; Du, Jin-Liang [Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081 (China); International Joint Research Laboratory for Fish Immunopharmacology, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081 (China); Wang, Jia-Hao; Liu, Ying-Juan [Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081 (China); Jeney, Galina [National Agricultural Research Center, Research Institute for Fisherie and, Aquaculture, Anna Light 8, Szarvas 5440 (Hungary); Xu, Pao, E-mail: xup@ffrc.cn [Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081 (China); Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081 (China); Yin, Guo-Jun, E-mail: yingj@ffrc.cn [Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081 (China); Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081 (China); International Joint Research Laboratory for Fish Immunopharmacology, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081 (China)

    2014-07-01

    Highlights: • We explored the underlying toxicology of CCl{sub 4} at the cellular and molecular levels. • QRT-PCR detected the gene expression of NF-κB and inflammatory cytokines. • The apoptosis and necrosis occurred simultaneously in carp liver damage. • CCl{sub 4} activated the TNF-α/NF-κB and TRL4/NF-κB signaling pathways. - Abstract: In the present study, the cellular and molecular mechanism of carbon tetrachloride (CCl{sub 4})-induced hepatotoxicity in fish was investigated by studying the effects of CCl{sub 4} on the oxidative stress, inflammatory response and hepatocyte apoptosis. Common carp were given an intraperitoneal injection of 30% CCl{sub 4} in arachis oil (0.5 ml/kg body weight). At 72 h post-injection, blood were collected to measure glutamate pyruvate transaminase (GPT), glutamate oxalate transaminase (GOT), superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), glutathione (GSH), total antioxidant capacity (T-AOC) and malondialdehyde (MDA), liver samples were taken to analyze toll-like receptor 4 (TLR4), cytochrome P450 2E1 (CYP2E1) and gene expressions of inflammatory cytokines and nuclear factor-κB (NF-κB/cREL). Cell viability and apoptosis were analyzed after treatment of the primary hepatocytes with CCl{sub 4} at 8 mM. The results showed that CCl{sub 4} significantly increased the levels of GPT, GOT, MDA, TLR4 and CYP2E1, reduced the levels of SOD, GPx, CAT, GSH and T-AOC, and up-regulated the gene expressions of NF-κB/cREL and inflammatory cytokines including tumor necrosis factor-α (TNF-α), inducible nitric oxide synthase (iNOS), IL-1β, IL-6 and IL-12. In vitro, CCl{sub 4} caused a dramatic loss in cell viability and induced hepatocyte apoptosis. Overall results suggest that oxidative stress lipid peroxidation, and TNF-α/NF-κB and TRL4/NF-κB signaling pathways play important roles in CCl{sub 4}-induced hepatotoxicity in fish.

  12. Fructose Mediated Non-Alcoholic Fatty Liver Is Attenuated by HO-1-SIRT1 Module in Murine Hepatocytes and Mice Fed a High Fructose Diet.

    Directory of Open Access Journals (Sweden)

    Komal Sodhi

    Full Text Available Oxidative stress underlies the etiopathogenesis of nonalcoholic fatty liver disease (NAFLD, obesity and cardiovascular disease (CVD. Heme Oxygenase-1 (HO-1 is a potent endogenous antioxidant gene that plays a key role in decreasing oxidative stress. Sirtuin1 (SIRT1 belongs to the family of NAD-dependent de-acyetylases and is modulated by cellular redox.We hypothesize that fructose-induced obesity creates an inflammatory and oxidative environment conducive to the development of NAFLD and metabolic syndrome. The aim of this study is to determine whether HO-1 acts through SIRT1 to form a functional module within hepatocytes to attenuate steatohepatitis, hepatic fibrosis and cardiovascular dysfunction.We examined the effect of fructose, on hepatocyte lipid accumulation and fibrosis in murine hepatocytes and in mice fed a high fructose diet in the presence and absence of CoPP, an inducer of HO-1, and SnMP, an inhibitor of HO activity. Fructose increased oxidative stress markers and decreased HO-1 and SIRT1 levels in hepatocytes (p<0.05. Further fructose supplementation increased FAS, PPARα, pAMPK and triglycerides levels; CoPP negated this increase. Concurrent treatment with CoPP and SIRT1 siRNA in hepatocytes increased FAS, PPARα, pAMPK and triglycerides levels suggesting that HO-1 is upstream of SIRT1 and suppression of SIRT1 attenuates the beneficial effects of HO-1. A high fructose diet increased insulin resistance, blood pressure, markers of oxidative stress and lipogenesis along with fibrotic markers in mice (p<0.05. Increased levels of HO-1 increased SIRT1 levels and ameliorated fructose-mediated lipid accumulation and fibrosis in liver along with decreasing vascular dysfunction (p<0.05 vs. fructose. These beneficial effects of CoPP were reversed by SnMP.Taken together, our study demonstrates, for the first time, that HO-1 induction attenuates fructose-induced hepatic lipid deposition, prevents the development of hepatic fibrosis and abates

  13. Glucose metabolism and recycling by hepatocytes of OB/OB and ob/ob mice

    International Nuclear Information System (INIS)

    Lahtela, J.T.; Wals, P.A.; Katz, J.

    1990-01-01

    Hepatocytes were prepared from livers of ob/ob (obese diabetic) mice and their lean (OB/OB) siblings that had been fasted for 24 h. The hepatocytes were incubated with [U-14C, 2-3H]-, [U-14C, 3-3H]-, and [U-14C, 6-3H]glucose at concentrations from 20 to 120 mM. 14C was recovered mainly in CO2, glycogen, and lactate. Tritium was recovered in water and glycogen. The yield in labeled products from [2-3H]glucose ranged from two to three times that from [U-14C]glucose. The yields from [3-3H]- and [6-3H]glucose were similar, and 1.3-1.7 times that from [U-14C]glucose. At 40 mM, total utilization of glucose by obese mice was about twice that for lean mice, but there was little difference at 120 mM. The rate of recycling between glucose and glucose 6-phosphate was calculated. An equation to calculate the rate of recycling of glucose from the 2-3H/U-14C ratio in glycogen is derived in the APPENDIX. Our results show that (1) the utilization of glucose by hepatocytes from obese diabetic mice exceeds that of their lean controls, (2) the rate of glucose phosphorylation in both groups greatly exceeds glucose uptake and the rate of glycogen synthesis, (3) glucose phosphorylation represents a difference between a high glucokinase rate and hydrolysis of glucose 6-phosphate, and (4) recycling of glucose carbon between glucose 6-phosphate and pyruvate occurs within mouse hepatocytes

  14. Prolyl hydroxylase-1 regulates hepatocyte apoptosis in an NF-κB-dependent manner

    Energy Technology Data Exchange (ETDEWEB)

    Fitzpatrick, Susan F.; Fábián, Zsolt; Schaible, Bettina; Lenihan, Colin R.; Schwarzl, Thomas [School of Medicine and Medical Science, The Conway Institute, University College Dublin, Belfield, Dublin 4 Ireland (Ireland); Rodriguez, Javier [Systems Biology Ireland, University College Dublin, Dublin 4 (Ireland); Zheng, Xingnan; Li, Zongwei [Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC (United States); Tambuwala, Murtaza M. [School of Pharmacy and Pharmaceutical Sciences, Ulster University, Coleraine, BT52 1SA, Northern Ireland (United Kingdom); Higgins, Desmond G.; O' Meara, Yvonne [School of Medicine and Medical Science, The Conway Institute, University College Dublin, Belfield, Dublin 4 Ireland (Ireland); Slattery, Craig [School of Biomolecular and Biomedical Science, The Conway Institute, University College Dublin, Belfield, Dublin 4 Ireland (Ireland); Manresa, Mario C. [School of Medicine and Medical Science, The Conway Institute, University College Dublin, Belfield, Dublin 4 Ireland (Ireland); Fraisl, Peter; Bruning, Ulrike [Laboratory of Angiogenesis and Vascular Metabolism, Department of Oncology, University of Leuven, Vesalius Research Center, VIB, B-3000 (Belgium); Baes, Myriam [Laboratory for Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven (Belgium); Carmeliet, Peter; Doherty, Glen [Laboratory of Angiogenesis and Vascular Metabolism, Department of Oncology, University of Leuven, Vesalius Research Center, VIB, B-3000 (Belgium); Kriegsheim, Alex von [Systems Biology Ireland, University College Dublin, Dublin 4 (Ireland); Cummins, Eoin P. [School of Medicine and Medical Science, The Conway Institute, University College Dublin, Belfield, Dublin 4 Ireland (Ireland); and others

    2016-06-03

    Hepatocyte death is an important contributing factor in a number of diseases of the liver. PHD1 confers hypoxic sensitivity upon transcription factors including the hypoxia inducible factor (HIF) and nuclear factor-kappaB (NF-κB). Reduced PHD1 activity is linked to decreased apoptosis. Here, we investigated the underlying mechanism(s) in hepatocytes. Basal NF-κB activity was elevated in PHD1{sup −/−} hepatocytes compared to wild type controls. ChIP-seq analysis confirmed enhanced binding of NF-κB to chromatin in regions proximal to the promoters of genes involved in the regulation of apoptosis. Inhibition of NF-κB (but not knock-out of HIF-1 or HIF-2) reversed the anti-apoptotic effects of pharmacologic hydroxylase inhibition. We hypothesize that PHD1 inhibition leads to altered expression of NF-κB-dependent genes resulting in reduced apoptosis. This study provides new information relating to the possible mechanism of therapeutic action of hydroxylase inhibitors that has been reported in pre-clinical models of intestinal and hepatic disease. -- Highlights: •Genetic ablation of PHD1 upregulates NF-kappaB (NF-κB) in hepatocytes. •Activation of NF-κB leads to differential DNA-binding of p50/p65 and results in differential regulation of apoptotic genes. •We identified proline 191 in the beta subunit of the I-kappaB kinase as a target for PHD1-mediated hydroxylation. •Blockade of prolyl-4-hydroxylases has been found cytoprotective in liver cells.

  15. Hepatocyte Hyperproliferation upon Liver-Specific Co-disruption of Thioredoxin-1, Thioredoxin Reductase-1, and Glutathione Reductase

    Directory of Open Access Journals (Sweden)

    Justin R. Prigge

    2017-06-01

    Full Text Available Energetic nutrients are oxidized to sustain high intracellular NADPH/NADP+ ratios. NADPH-dependent reduction of thioredoxin-1 (Trx1 disulfide and glutathione disulfide by thioredoxin reductase-1 (TrxR1 and glutathione reductase (Gsr, respectively, fuels antioxidant systems and deoxyribonucleotide synthesis. Mouse livers lacking both TrxR1 and Gsr sustain these essential activities using an NADPH-independent methionine-consuming pathway; however, it remains unclear how this reducing power is distributed. Here, we show that liver-specific co-disruption of the genes encoding Trx1, TrxR1, and Gsr (triple-null causes dramatic hepatocyte hyperproliferation. Thus, even in the absence of Trx1, methionine-fueled glutathione production supports hepatocyte S phase deoxyribonucleotide production. Also, Trx1 in the absence of TrxR1 provides a survival advantage to cells under hyperglycemic stress, suggesting that glutathione, likely via glutaredoxins, can reduce Trx1 disulfide in vivo. In triple-null livers like in many cancers, deoxyribonucleotide synthesis places a critical yet relatively low-volume demand on these reductase systems, thereby favoring high hepatocyte turnover over sustained hepatocyte integrity.

  16. Inhibition of Drp1 protects against senecionine-induced mitochondria-mediated apoptosis in primary hepatocytes and in mice

    Directory of Open Access Journals (Sweden)

    Xiao Yang

    2017-08-01

    Full Text Available Pyrrolizidine alkaloids (PAs are a group of compounds found in various plants and some of them are widely consumed in the world as herbal medicines and food supplements. PAs are potent hepatotoxins that cause irreversible liver injury in animals and humans. However, the mechanisms by which PAs induce liver injury are not clear. In the present study, we determined the hepatotoxicity and molecular mechanisms of senecionine, one of the most common toxic PAs, in primary cultured mouse and human hepatocytes as well as in mice. We found that senecionine administration increased serum alanine aminotransferase levels in mice. H&E and TUNEL staining of liver tissues revealed increased hemorrhage and hepatocyte apoptosis in liver zone 2 areas. Mechanistically, senecionine induced loss of mitochondrial membrane potential, release of mitochondrial cytochrome c as well as mitochondrial JNK translocation and activation prior to the increased DNA fragmentation and caspase-3 activation in primary cultured mouse and human hepatocytes. SP600125, a specific JNK inhibitor, and ZVAD-fmk, a general caspase inhibitor, alleviated senecionine-induced apoptosis in primary hepatocytes. Interestingly, senecionine also caused marked mitochondria fragmentation in hepatocytes. Pharmacological inhibition of dynamin-related protein1 (Drp1, a protein that is critical to regulate mitochondrial fission, blocked senecionine-induced mitochondrial fragmentation and mitochondrial release of cytochrome c and apoptosis. More importantly, hepatocyte-specific Drp1 knockout mice were resistant to senecionine-induced liver injury due to decreased mitochondrial damage and apoptosis. In conclusion, our results uncovered a novel mechanism of Drp1-mediated mitochondrial fragmentation in senecionine-induced liver injury. Targeting Drp1-mediated mitochondrial fragmentation and apoptosis may be a potential avenue to prevent and treat hepatotoxicity induced by PAs. Keywords: Senecionine, Drp1

  17. The metabolism of aflatoxin B1 by hepatocytes isolated from rats following the in vivo administration of some xenobiotics

    International Nuclear Information System (INIS)

    Metcalfe, S.A.; Neal, G.E.

    1983-01-01

    Isolated rat hepatocytes, an intact cellular system capable of performing phase I and phase II metabolism, have been used to investigate metabolism of aflatoxin B1. These cells were found to metabolise [ 14 C]aflatoxin B1 to aflatoxins M1 and Q1, and to radiolabelled polar material, presumably conjugates, as analysed by h.p.l.c., t.l.c. and radioactive determination. In vivo administration of the mixed function oxidase inducers, phenobarbitone and 3-methylcholanthrene, resulted in enhanced hepatocyte phase I (microsomal) metabolism of aflatoxin B1. In contrast to metabolism of AFB1 by in vitro subcellular systems increased production of polar material (conjugated metabolites) derived from [ 14 C]aflatoxin B1 was also detected in hepatocytes isolated from these pretreated animals. Formation of aflatoxin Q1 by isolated hepatocytes appeared to be mediated by cytochrome P450-linked enzymes whereas cytochrome P448-linked enzymes were apparently involved in aflatoxin M1 production. Chronic feeding of aflatoxin B1 to rats enhanced hepatocyte production of conjugated material only and did not elevate cellular cytochrome P450 levels, thus suggesting that aflatoxin B1 is not an inducer of its own primary metabolism

  18. Protective effect of kombucha tea against tertiary butyl hydroperoxide induced cytotoxicity and cell death in murine hepatocytes.

    Science.gov (United States)

    Bhattacharya, Semantee; Manna, Prasenjit; Gachhui, Ratan; Sil, Parames C

    2011-07-01

    Kombucha (KT), a fermented black tea (BT), is known to have many beneficial properties. In the present study, antioxidant property of KT has been investigated against tertiary butyl hydroperoxide (TBHP) induced cytotoxicity using murine hepatocytes. TBHP, a reactive oxygen species inducer, causes oxidative stress resulting in organ pathophysiology. Exposure to TBHP caused a reduction in cell viability, increased membrane leakage and disturbed the intra-cellular antioxidant machineries in hepatocytes. TBHP exposure disrupted mitochondrial membrane potential and induced apoptosis as evidenced by flow cytometric analyses. KT treatment, however, counteracted the changes in mitochondrial membrane potential and prevented apoptotic cell death of the hepatocytes. BT treatment also reverted TBHP induced hepatotoxicity, however KT was found to be more efficient. This may be due to the formation of antioxidant molecules like D-saccharic acid-1,4-lactone (DSL) during fermentation process and are absent in BT. Moreover, the radical scavenging activities of KT were found to be higher than BT. Results of the study showed that KT has the potential to ameliorate TBHP induced oxidative insult and cell death in murine hepatocytes more effectively than BT.

  19. 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. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Radiation-induced PKC signaling system in cultured rat hepatocytes

    International Nuclear Information System (INIS)

    Nakajima, Tetsuo; Yukawa, Osami

    1998-01-01

    Radiation effects on living organisms are mainly caused through reactive oxygen species (ROS) on living cells. It is known that ROS damages various membranes and the bio membranes play an important role in cellular signal transduction pathways. The effects of radiation on cellular signal transduction pathways in cultured rat hepatocytes have been studied

  1. Preventive effects of fructose and N-acetyl-L-cysteine against cytotoxicity induced by the psychoactive compounds N-methyl-5-(2-aminopropyl)benzofuran and 3,4-methylenedioxy-N-methamphetamine in isolated rat hepatocytes.

    Science.gov (United States)

    Nakagawa, Yoshio; Suzuki, Toshinari; Inomata, Akiko

    2018-02-01

    Psychoactive compounds, N-methyl-5-(2-aminopropyl)benzofuran (5-MAPB) and 3,4-methylenedioxy-N-methamphetamine (MDMA), are known to be hepatotoxic in humans and/or experimental animals. As previous studies suggested that these compounds elicited cytotoxicity via mitochondrial dysfunction and/or oxidative stress in rat hepatocytes, the protective effects of fructose and N-acetyl-l-cysteine (NAC) on 5-MAPB- and MDMA-induced toxicity were studied in rat hepatocytes. These drugs caused not only concentration-dependent (0-4 mm) and time-dependent (0-3 hours) cell death accompanied by the depletion of cellular levels of adenosine triphosphate (ATP) and glutathione (reduced form; GSH) but also an increase in the oxidized form of GSH. The toxic effects of 5-MAPB were greater than those of MDMA. Pretreatment of hepatocytes with either fructose at a concentration of 10 mm or NAC at a concentration of 2.5 mm prevented 5-MAPB-/MDMA-induced cytotoxicity. In addition, the exposure of hepatocytes to 5-MAPB/MDMA caused the loss of mitochondrial membrane potential, although the preventive effect of fructose was weaker than that of NAC. These results suggest that: (1) 5-MAPB-/MDMA-induced cytotoxicity is linked to mitochondrial failure and depletion of cellular GSH; (2) insufficient cellular ATP levels derived from mitochondrial dysfunction were ameliorated, at least in part, by the addition of fructose; and (3) GSH loss via oxidative stress was prevented by NAC. Taken collectively, these results indicate that the onset of toxic effects caused by 5-MAPB/MDMA may be partially attributable to cellular energy stress as well as oxidative stress. Copyright © 2017 John Wiley & Sons, Ltd.

  2. Differential Impacts of Soybean and Fish Oils on Hepatocyte Lipid Droplet Accumulation and Endoplasmic Reticulum Stress in Primary Rabbit Hepatocytes

    OpenAIRE

    Zhu, Xueping; Xiao, Zhihui; Xu, Yumin; Zhao, Xingli; Cheng, Ping; Cui, Ningxun; Cui, Mingling; Li, Jie; Zhu, Xiaoli

    2016-01-01

    Parenteral nutrition-associated liver disease (PNALD) is a severe ailment associated with long-term parenteral nutrition. Soybean oil-based lipid emulsions (SOLE) are thought to promote PNALD development, whereas fish oil-based lipid emulsions (FOLE) are thought to protect against PNALD. This study aimed to investigate the effects of SOLE and FOLE on primary rabbit hepatocytes. The results reveal that SOLE caused significant endoplasmic reticulum (ER) and mitochondrial damage, ultimately resu...

  3. Spatiotemporal multiple coherence resonances and calcium waves in a coupled hepatocyte system

    International Nuclear Information System (INIS)

    Bao-Hua, Wang; Qi-Shao, Lu; Shu-Juan, Lü; Xiu-Feng, Lang

    2009-01-01

    Spatiotemporal multiple coherence resonances for calcium activities induced by weak Gaussian white noise in coupled hepatocytes are studied. It is shown that bi-resonances in hepatocytes are induced by the interplay and competition between noise and coupling of cells, in other words, the cell in network can be excited either by noise or by its neighbour via gap junction which can transfer calcium ions between cells. Furthermore, the intercellular annular calcium waves induced by noise are observed, in which the wave length decreases with noise intensity augmenting but increases monotonically with coupling strength increasing. And for a fixed noise level, there is an optimal coupling strength that makes the coherence resonance reach maximum. (general)

  4. Calcium-mediated signaling and calmodulin-dependent kinase regulate hepatocyte-inducible nitric oxide synthase expression.

    Science.gov (United States)

    Zhang, Baochun; Crankshaw, Will; Nesemeier, Ryan; Patel, Jay; Nweze, Ikenna; Lakshmanan, Jaganathan; Harbrecht, Brian G

    2015-02-01

    Induced nitric oxide synthase (iNOS) is induced in hepatocytes by shock and inflammatory stimuli. Excessive NO from iNOS mediates shock-induced hepatic injury and death, so understanding the regulation of iNOS will help elucidate the pathophysiology of septic shock. In vitro, cytokines induce iNOS expression through activation of signaling pathways including mitogen-activated protein kinases and nuclear factor κB. Cytokines also induce calcium (Ca(2+)) mobilization and activate calcium-mediated intracellular signaling pathways, typically through activation of calmodulin-dependent kinases (CaMK). Calcium regulates NO production in macrophages but the role of calcium and calcium-mediated signaling in hepatocyte iNOS expression has not been defined. Primary rat hepatocytes were isolated, cultured, and induced to produce NO with proinflammatory cytokines. Calcium mobilization and Ca(2+)-mediated signaling were altered with ionophore, Ca(2+) channel blockers, and inhibitors of CaMK. The Ca(2+) ionophore A23187 suppressed cytokine-stimulated NO production, whereas Ethylene glycol tetraacetic acid and nifedipine increased NO production, iNOS messenger RNA, and iNOS protein expression. Inhibition of CaMK with KN93 and CBD increased NO production but the calcineurin inhibitor FK 506 decreased iNOS expression. These data demonstrate that calcium-mediated signaling regulates hepatocyte iNOS expression and does so through a mechanism independent of calcineurin. Changes in intracellular calcium levels may regulate iNOS expression during hepatic inflammation induced by proinflammatory cytokines. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Utilization of supplemental methionine sources by primary cultures of chick hepatocytes

    International Nuclear Information System (INIS)

    Dibner, J.J.

    1983-01-01

    Utilization of 2-hydroxy-4-(methylthio) butanoic acid (HMB) as a substrate for protein synthesis was studied by using primary cultures of chick liver cells. Cultures were prepared by enzymatic dissociation of livers from week old Hubbard broiler chicks and were maintained for 4 days under nonproliferative conditions. Hepatocyte differentiation was verified by using dexamethasone induction of tyrosine aminotransferase activity. Conversion of [14C]HMB to L-methionine was shown by chromatographic analysis of hepatocyte protein hydrolysate and incorporation into protein was proven by cycloheximide inhibition of synthesis. When incorporation of HMB was compared to that of DL-methionine (DLM) equimolar quantities of the two sources were found in liver cell protein. These results support, at a cellular level, the conclusion that HMB and DLM are biochemically equivalent sources of methionine for protein synthesis

  6. Curcumin inhibits activation of TRPM2 channels in rat hepatocytes

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    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.

  7. Direct induction of hepatocyte-like cells from immortalized human bone marrow mesenchymal stem cells by overexpression of HNF4α

    International Nuclear Information System (INIS)

    Hu, Xiaojun; Xie, Peiyi; Li, Weiqiang; Li, Zhengran; Shan, Hong

    2016-01-01

    Hepatocytes from human bone marrow-derived mesenchymal stem cells (hBM-MSCs) are expected to be a useful source for cell transplantation. However, relatively low efficiency and repeatability of hepatic differentiation of human BM-MSCs remains an obstacle for clinical translation. Hepatocyte nuclear factor 4 alpha (HNF4α), a critical transcription factor, plays an essential role in the entire process of liver development. In this study, immortalized hBM-MSCs, UE7T-13 cells were transduced with a lentiviral vector containing HNF4α. The typical fibroblast-like morphology of the MSCs changed, and polygonal, epithelioid cells grew out after HNF4α transduction. In hepatocyte culture medium, HNF4α-transduced MSCs (E7-hHNF4α cells) strongly expressed the albumin (ALB), CYP2B6, alpha-1 antitrypsin (AAT), and FOXA2 mRNA and exhibited morphology markedly similar to that of mature hepatocytes. The E7-hHNF4α cells showed hepatic functions such as Indocyanine green (ICG) uptake and release, glycogen storage, urea production and ALB secretion. Approximately 28% of E7-hHNF4α cells expressed both ALB and AAT. Furthermore, these E7-hHNF4α cells via superior mesenteric vein (SMV) injection expressed human ALB in mouse chronic injured liver. In conclusion, this study represents a novel strategy by directly inducing hepatocyte-like cells from MSCs. - Highlights: • We overexpressed HNF4α in immortalized BM-MSCs by lentiviral transduction. • HNF4α-transduced MSCs transdifferentiated into hepatocytes with mature hepatic metabolic functions. • Our study represents a novel strategy by direct induction of hepatocyte-like cells from MSCs.

  8. Aluminum Exposure from Parenteral Nutrition: Early Bile Canaliculus Changes of the Hepatocyte

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    Amanda R. Hall

    2018-06-01

    Full Text Available Background: Neonates on long-term parenteral nutrition (PN may develop parenteral nutrition-associated liver disease (PNALD. Aluminum (Al is a known contaminant of infant PN, and we hypothesize that it substantially contributes to PNALD. In this study, we aim to assess the impact of Al on hepatocytes in a piglet model. Methods: We conducted a randomized control trial using a Yucatan piglet PN model. Piglets, aged 3–6 days, were placed into two groups. The high Al group (n = 8 received PN with 63 µg/kg/day of Al, while the low Al group (n = 7 received PN with 24 µg/kg/day of Al. Serum samples for total bile acids (TBA were collected over two weeks, and liver tissue was obtained at the end of the experiment. Bile canaliculus morphometry were studied by transmission electron microscopy (TEM and ImageJ software analysis. Results: The canalicular space was smaller and the microvilli were shorter in the high Al group than in the low Al group. There was no difference in the TBA between the groups. Conclusions: Al causes structural changes in the hepatocytes despite unaltered serum bile acids. High Al in PN is associated with short microvilli, which could decrease the functional excretion area of the hepatocytes and impair bile flow.

  9. Modulation of Mitochondrial DNA Copy Number to Induce Hepatocytic Differentiation of Human Amniotic Epithelial Cells.

    Science.gov (United States)

    Vaghjiani, Vijesh; Cain, Jason E; Lee, William; Vaithilingam, Vijayaganapathy; Tuch, Bernard E; St John, Justin C

    2017-10-15

    Mitochondrial deoxyribonucleic acid (mtDNA) copy number is tightly regulated during pluripotency and differentiation. There is increased demand of cellular adenosine triphosphate (ATP) during differentiation for energy-intensive cell types such as hepatocytes and neurons to meet the cell's functional requirements. During hepatocyte differentiation, mtDNA copy number should be synchronously increased to generate sufficient ATP through oxidative phosphorylation. Unlike bone marrow mesenchymal cells, mtDNA copy number failed to increase by 28 days of differentiation of human amniotic epithelial cells (hAEC) into hepatocyte-like cells (HLC) despite their expression of some end-stage hepatic markers. This was due to higher levels of DNA methylation at exon 2 of POLGA, the mtDNA-specific replication factor. Treatment with a DNA demethylation agent, 5-azacytidine, resulted in increased mtDNA copy number, reduced DNA methylation at exon 2 of POLGA, and reduced hepatic gene expression. Depletion of mtDNA followed by subsequent differentiation did not increase mtDNA copy number, but reduced DNA methylation at exon 2 of POLGA and increased expression of hepatic and pluripotency genes. We encapsulated hAEC in barium alginate microcapsules and subsequently differentiated them into HLC. Encapsulation resulted in no net increase of mtDNA copy number but a significant reduction in DNA methylation of POLGA. RNAseq analysis showed that differentiated HLC express hepatocyte-specific genes but also increased expression of inflammatory interferon genes. Differentiation in encapsulated cells showed suppression of inflammatory genes as well as increased expression of genes associated with hepatocyte function pathways and networks. This study demonstrates that an increase in classical hepatic gene expression can be achieved in HLC through encapsulation, although they fail to effectively regulate mtDNA copy number.

  10. Cadmium-induced apoptosis through the mitochondrial pathway in rainbow trout hepatocytes: involvement of oxidative stress

    International Nuclear Information System (INIS)

    Risso-de Faverney, C.; Orsini, N.; Sousa, G. de; Rahmani, R.

    2004-01-01

    Cadmium (Cd) induces oxidative stress and apoptosis in trout hepatocytes. We therefore investigated the involvement of the mitochondrial pathway in the initiation of apoptosis and the possible role of oxidative stress in that process. This study demonstrates that hepatocyte exposure to Cd (2, 5 and 10 μM) triggers significant caspase-3, but also caspase-8 and -9 activation in a dose-dependent manner. Western-blot analysis of hepatocyte mitochondrial and cytosolic fractions revealed that cytochrome c (Cyt c) was released in the cytosol in a dose-dependent manner, whereas the pro-apoptotic protein Bax was redistributed to mitochondria after 24 and 48 h exposure. We also found that the expression of anti-apoptotic protein Bcl-xL, known to be regulated under mild oxidative stress to protect cells from apoptosis, did not change after 3 and 6 h exposure to Cd, then increased after 24 and 48 h exposure to 10 μM Cd. In the second part of this work, two antioxidant agents, 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO) (100 μM) and N-acetylcysteine (NAC, 100 μM) were used to determine the involvement of reactive oxygen species (ROS) in Cd-induced apoptosis. Simultaneously exposing trout hepatocytes to Cd and TEMPO or NAC significantly reduced caspase-3 activation after 48 h and had a suppressive effect on caspase-8 and -9 also, mostly after 24 h. Lastly, the presence of either one of these antioxidants in the treatment medium also attenuated Cd-induced Cyt c release in cytosol and the level of Bax in the mitochondria after 24 and 48 h, while high Bcl-xL expression was observed. Taken together, these data clearly evidenced the key role of mitochondria in the cascade of events leading to trout hepatocyte apoptosis in response to Cd and the relationship that exists between oxidative stress and cell death

  11. Efficient Generation of Functional Hepatocytes From Human Embryonic Stem Cells and Induced Pluripotent Stem Cells by HNF4α Transduction

    OpenAIRE

    Takayama, Kazuo; Inamura, Mitsuru; Kawabata, Kenji; Katayama, Kazufumi; Higuchi, Maiko; Tashiro, Katsuhisa; Nonaka, Aki; Sakurai, Fuminori; Hayakawa, Takao; Kusuda Furue, Miho; Mizuguchi, Hiroyuki

    2012-01-01

    Hepatocyte-like cells from human embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) are expected to be a useful source of cells drug discovery. Although we recently reported that hepatic commitment is promoted by transduction of SOX17 and HEX into human ESC- and iPSC-derived cells, these hepatocyte-like cells were not sufficiently mature for drug screening. To promote hepatic maturation, we utilized transduction of the hepatocyte nuclear factor 4α (HNF4α) gene, which is kn...

  12. Liver fatty acid binding protein is the mitosis-associated polypeptide target of a carcinogen in rat hepatocytes

    International Nuclear Information System (INIS)

    Bassuk, J.A.; Tsichlis, P.N.; Sorof, S.

    1987-01-01

    Hepatocytes in normal rat liver were found previously to contain a cytoplasmic 14,000-dalton polypeptide (p14) that is associated with mitosis and is the principal early covalent target of activated metabolites of the carcinogen N-2-fluorenylacetamide (2-acetylaminofluorene). The level of immunohistochemically detected p14 was low when growth activity of hepatocytes was low, was markedly elevated during mitosis in normal and regenerating livers, but was very high throughout interphase during proliferation of hyperplastic and malignant hepatocytes induced in rat liver by a carcinogen (N-2-fluorenylacetamide or 3'-methyl-4-dimethylaminoazobenzene). The authors report here that p14 is the liver fatty acid binding protein. The nucleotide sequence of p14 cDNA clones, isolated by screening a rat liver cDNA library in bacteriophage λgt11 using p14 antiserum, was completely identical to part of the sequence reported for liver fatty acid binding protein. Furthermore, the two proteins shared the following properties: size of mRNA, amino acid composition, molecular size according to NaDodSO 4 gel electrophoresis, and electrophoretic mobilities in a Triton X-100/acetic acid/urea gel. The two polypeptides bound oleic acid similarly. Finally, identical elevations of cytoplasmic immunostain were detected specifically in mitotic hepatocytes with either antiserum. The collected findings are suggestive that liver fatty acid binding protein may carry ligands that promote hepatocyte division and may transport certain activated chemical carcinogens

  13. Study of Valproic Acid-Enhanced Hepatocyte Steatosis

    Science.gov (United States)

    Chang, Renin; Chou, Mei-Chia; Hung, Li-Ying; Wang, Mu-En; Hsu, Meng-Chieh; Chiu, Chih-Hsien

    2016-01-01

    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. PMID:27034954

  14. Study of Valproic Acid-Enhanced Hepatocyte Steatosis

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    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.

  15. Ketose induced respiratory inhibition in isolated hepatocytes.

    Science.gov (United States)

    Martínez, P; Carrascosa, J M; Núñez de Castro, I

    1987-06-01

    The addition of 10 mM fructose or 10 mM tagatose to a suspension of hepatocytes caused respiratory inhibition, whereas no change in oxygen uptake was observed following the addition of glucose. However, incubations in the presence of fructose showed a high, aerobic glycolytic activity. Tagatose is phosphorylated to tagatose 1-phosphate but is not further metabolized by cell free liver extract. Moreover, the addition of fructose to glucagon treated cells also caused the Crabtree-like effect. The concentration of adenine nucleotides and inorganic phosphate (Pi) in the mitochondrial and cytosolic compartments during incubation (time 30 min) was determined by the digitonin fractionation procedure. In the presence of 10 mM fructose or tagatose, the total adenine nucleotide pools decreased by 40%; however, glucose produced no change. The addition of ketoses diminished the asymmetric distribution of extramitochondrial (ATP/ADP)e ratio and intramitochondrial (ATP/ADP)i ratio. At the same time the total mitochondrial Pi fell from 17 mM to 6-7 mM. The mitochondrial membrane potential (-161 mV) in the presence of fructose showed no changes during the 30 min experimental period. An increase in the NADH/NAD+ ratio was observed. These results suggest that in hepatocytes the inhibition of respiration is not necessarily linked with the enhanced aerobic glycolysis, by competition for common substrates.

  16. Hepatocytes polyploidization and cell cycle control in liver physiopathology.

    Science.gov (United States)

    Gentric, Géraldine; Desdouets, Chantal; Celton-Morizur, Séverine

    2012-01-01

    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.

  17. Hepatocytes Polyploidization and Cell Cycle Control in Liver Physiopathology

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    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.

  18. Tangeretin and its metabolite 4'-hydroxytetramethoxyflavone attenuate EGF-stimulated cell cycle progression in hepatocytes; role of inhibition at the level of mTOR/p70S6K.

    Science.gov (United States)

    Cheng, Z; Surichan, S; Ruparelia, K; Arroo, R; Boarder, M R

    2011-04-01

    The mechanisms by which the dietary compound tangeretin has anticancer effects may include acting as a prodrug, forming an antiproliferative product in cancer cells. Here we show that tangeretin also inhibits cell cycle progression in hepatocytes and investigate the role of its primary metabolite 4'-hydroxy-5,6,7,8-tetramethoxyflavone (4'-OH-TMF) in this effect. We used epidermal growth factor (EGF)-stimulated rat hepatocytes, with [(3)H]-thymidine incorporation into DNA as an index of progression to S-phase of the cell cycle, and Western blots for phospho-proteins involved in the cell signalling cascade. Incubation of tangeretin with microsomes expressing CYP1A, or with hepatocytes, generated a primary product we identified as 4'-OH-TMF. Low micromolar concentrations of tangeretin or 4'-OH-TMF gave a concentration-dependent inhibition of EGF-stimulated progression to S-phase while having little effect on cell viability. To determine whether time for conversion of tangeretin to an active metabolite would enhance the inhibitory effect we used long pre-incubations; this reduced the inhibitory effect, in parallel with a reduction in the concentration of tangeretin. The EGF-stimulation of hepatocyte cell cycle progression requires signalling through Akt/mTOR/p70S6K kinase cascades. The tangeretin metabolite 4'-OH-TMF selectively inhibited S6K phosphorylation in the absence of significant inhibition of upstream Akt activity, suggesting an effect at the level of mTOR. Tangeretin and 4'-OH-TMF both inhibit cell cycle progression in primary hepatocytes. The inhibition of p70S6K phosphorylation by 4'-OH-TMF raises the possibility that inhibition of the mTOR pathway may contribute to the anticancer influence of a flavonoid-rich diet. © 2011 The Authors. British Journal of Pharmacology © 2011 The British Pharmacological Society.

  19. Glutathione depletion by valproic acid in sandwich-cultured rat hepatocytes: Role of biotransformation and temporal relationship with onset of toxicity

    International Nuclear Information System (INIS)

    Kiang, Tony K.L.; Teng Xiaowei; Surendradoss, Jayakumar; Karagiozov, Stoyan; Abbott, Frank S.; Chang, Thomas K.H.

    2011-01-01

    The present study was conducted in sandwich-cultured rat hepatocytes to investigate the chemical basis of glutathione (GSH) depletion by valproic acid (VPA) and evaluate the role of GSH depletion in VPA toxicity. Among the synthetic metabolites of VPA investigated, 4-ene-VPA and (E)-2,4-diene-VPA decreased cellular levels of total GSH, but only (E)-2,4-diene-VPA was more effective and more potent than the parent drug. The in situ generated, cytochrome P450-dependent 4-ene-VPA did not contribute to GSH depletion by VPA, as suggested by the experiment with a cytochrome P450 inhibitor, 1-aminobenzotriazole, to decrease the formation of this metabolite. In support of a role for metabolites, alpha-F-VPA and octanoic acid, which do not undergo biotransformation to form a 2,4-diene metabolite, CoA ester, or glucuronide, did not deplete GSH. A time course experiment showed that GSH depletion did not occur prior to the increase in 2',7'-dichlorofluorescein (a marker of oxidative stress), the decrease in [2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium] (WST-1) product formation (a marker of cell viability), or the increase in lactate dehydrogenase (LDH) release (a marker of necrosis) in VPA-treated hepatocytes. In conclusion, the cytochrome P450-mediated 4-ene-VPA pathway does not play a role in the in situ depletion of GSH by VPA, and GSH depletion is not an initiating event in VPA toxicity in sandwich-cultured rat hepatocytes.

  20. Hepatoprotective effects of Poly-[hemoglobin-superoxide dismutase-catalase-carbonic anhydrase] on alcohol-damaged primary rat hepatocyte culture in vitro.

    Science.gov (United States)

    Jiang, Wenhua; Bian, Yuzhu; Wang, Zhenghui; Chang, Thomas Ming Swi

    2017-02-01

    We have prepared a novel nanobiotherapeutic, Poly-[hemoglobin-superoxide dismutase-catalase-carbonic anhydrase], which not only transports both oxygen and carbon dioxide but also a therapeutic antioxidant. Our previous study in a severe sustained 90 min hemorrhagic shock rat model shows that it has a hepatoprotective effect. We investigate its hepatoprotective effect further in this present report using an alcohol-damaged primary hepatocyte culture model. Results show that it significantly reduced ethanol-induced AST release, lipid peroxidation, and ROS production in rat primary hepatocytes culture. It also significantly enhanced the viability of ethanol-treated hepatocytes. Thus, the result shows that Poly-[hemoglobin-superoxide dismutase-catalase-carbonic anhydrase] also has some hepatoprotective effects against alcohol-induced injury in in vitro rat primary hepatocytes cell culture. This collaborate our previous observation of its hepatoprotective effect in a severe sustained 90-min hemorrhagic shock rat model.

  1. Apelin ameliorates TNF-α-induced reduction of glycogen synthesis in the hepatocytes through G protein-coupled receptor APJ.

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    Jiaojiao Chu

    Full Text Available Apelin, a novel adipokine, is the specific endogenous ligand of G protein-coupled receptor APJ. Consistent with its putative role as an adipokine, apelin has been linked to states of insulin resistance. However, the function of apelin in hepatic insulin resistance, a vital part of insulin resistance, and its underlying mechanisms still remains unclear. Here we define the impacts of apelin on TNF-α-induced reduction of glycogen synthesis in the hepatocytes. Our studies indicate that apelin reversed TNF-α-induced reduction of glycogen synthesis in HepG2 cells, mouse primary hepatocytes and liver tissues of C57BL/6J mice by improving JNK-IRS1-AKT-GSK pathway. Moreover, Western blot revealed that APJ, but not apelin, expressed in the hepatocytes and liver tissues of mice. We found that F13A, a competitive antagonist for G protein-coupled receptor APJ, suppressed the effects of apelin on TNF-α-induced reduction of glycogen synthesis in the hepatocytes, suggesting APJ is involved in the function of apelin. In conclusion, we show novel evidence suggesting that apelin ameliorates TNF-α-induced reduction of glycogen synthesis in the hepatocytes through G protein-coupled receptor APJ. Apelin appears as a beneficial adipokine with anti-insulin resistance properties, and thus as a promising therapeutic target in metabolic disorders.

  2. Hepatocyte polyploidization and its association with pathophysiological processes

    OpenAIRE

    Wang, Min-Jun; Chen, Fei; Lau, Joseph T Y; Hu, Yi-Ping

    2017-01-01

    A characteristic cellular feature of the mammalian liver is the progressive polyploidization of the hepatocytes, where individual cells acquire more than two sets of chromosomes. Polyploidization results from cytokinesis failure that takes place progressively during the course of postnatal development. The proportion of polyploidy also increases with the aging process or with cellular stress such as surgical resection, toxic stimulation, metabolic overload, or oxidative damage, to involve as ...

  3. Isoferritins in rat Kupffer cells, hepatocytes, and extrahepatic macrophages. Biosynthesis in cell suspensions and cultures in response to iron

    International Nuclear Information System (INIS)

    Doolittle, R.L.; Richter, G.W.

    1981-01-01

    Cultures of Kupffer cells and of hepatocytes, prepared from single rat livers, synthesized ferritin protein equally efficiently. In culture but not in suspension, both sorts of cells responded significantly to stimulation with iron by increased ferritin synthesis. As determined by isoelectric focusing, the isoferritin profiles of newly synthesized 14 -labeled Kupffer cell and hepatocyte ferritin were identical, each having three bands. However, unlabeled ferritin, extracted from nonparenchymal liver cells (mainly Kupffer and endothelial cells) of iron-loaded rats, contained an acidic isoferritin that was not present in hepatocyte ferritin. Investigation of ferritin synthesis in cultured peritoneal and alveolar macrophages yielded similar results. The isofocusing profile of newly synthesized peritoneal macrophage ferritin was indistinguishable from the profile of fresh Kupffer cell or hepatocyte ferritin. Thus, the three isoferritins common to Kupffer cells, hepatocytes, and extrahepatic macrophages are neither cell- nor tissue-specific. However, modifications on intracellular storage may affect the isofocusing properties. The findings, although consistent with the LnH24-n subunit model of ferritin protein, indicate identical restrictive genomic control of the H:L ratios in these sorts of cells. Further, they make it probable that Kupffer cell ferritin iron, originating by endogenous synthesis, is the principal source of Kupffer cell hemosiderin iron

  4. Effect of Microenvironment on Differentiation of Human Umbilical Cord Mesenchymal Stem Cells into Hepatocytes In Vitro and In Vivo

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    Gai Xue

    2016-01-01

    Full Text Available Human umbilical cord-derived mesenchymal stem cells (hUCMSCs are considered to be an ideal cell source for cell therapy of many diseases. The aim of this study was to investigate the contribution of the microenvironment to the hepatic differentiation potential of hUCMSCs in vitro and in vivo and to explore their therapeutic use in acute liver injury in rats. We established a new model to simulate the liver tissue microenvironment in vivo using liver homogenate supernatant (LHS in vitro. This induced environment could drive hUCMSCs to differentiate into hepatocyte-like cells within 7 days. The differentiated cells expressed hepatocyte-specific markers and demonstrated hepatocellular functions. We also injected hUCMSCs into rats with CCl4-induced acute hepatic injury. The hUCMSCs were detected in the livers of recipient rats and expressed the human hepatocyte-specific markers, suggesting that hUCMSCs could differentiate into hepatocyte-like cells in vivo in the liver tissue microenvironment. Levels of biochemistry markers improved significantly after transplantation of hUCMSCs compared with the nontransplantation group (P<0.05. In conclusion, this study demonstrated that the liver tissue microenvironment may contribute to the differentiation of hUCMSCs into hepatocytes both in vitro and in vivo.

  5. Effect of Microenvironment on Differentiation of Human Umbilical Cord Mesenchymal Stem Cells into Hepatocytes In Vitro and In Vivo

    Science.gov (United States)

    Xue, Gai; Han, Xiaolei; Ma, Xin; Wu, Honghai; Qin, Yabin; Liu, Jianfang; Hu, Yuqin; Hong, Yang; Hou, Yanning

    2016-01-01

    Human umbilical cord-derived mesenchymal stem cells (hUCMSCs) are considered to be an ideal cell source for cell therapy of many diseases. The aim of this study was to investigate the contribution of the microenvironment to the hepatic differentiation potential of hUCMSCs in vitro and in vivo and to explore their therapeutic use in acute liver injury in rats. We established a new model to simulate the liver tissue microenvironment in vivo using liver homogenate supernatant (LHS) in vitro. This induced environment could drive hUCMSCs to differentiate into hepatocyte-like cells within 7 days. The differentiated cells expressed hepatocyte-specific markers and demonstrated hepatocellular functions. We also injected hUCMSCs into rats with CCl4-induced acute hepatic injury. The hUCMSCs were detected in the livers of recipient rats and expressed the human hepatocyte-specific markers, suggesting that hUCMSCs could differentiate into hepatocyte-like cells in vivo in the liver tissue microenvironment. Levels of biochemistry markers improved significantly after transplantation of hUCMSCs compared with the nontransplantation group (P < 0.05). In conclusion, this study demonstrated that the liver tissue microenvironment may contribute to the differentiation of hUCMSCs into hepatocytes both in vitro and in vivo. PMID:27088093

  6. Usage of adenovirus expressing thymidine kinase mediated hepatocellular damage for enabling mouse liver repopulation with allogenic or xenogenic hepatocytes.

    Directory of Open Access Journals (Sweden)

    Daniel Moreno

    Full Text Available It has been shown that the liver of immunodeficient mice can be efficiently repopulated with human hepatocytes when subjected to chronic hepatocellular damage. Mice with such chimeric livers represent useful reagents for medical and clinical studies. However all previously reported models of humanized livers are difficult to implement as they involve cross-breeding of immunodeficient mice with mice exhibiting genetic alterations causing sustained hepatic injury. In this paper we attempted to create chimeric livers by inducing persistent hepatocellular damage in immunodeficient Rag2(-/- γc(-/- mice using an adenovirus encoding herpes virus thymidine kinase (AdTk and two consecutive doses of ganciclovir (GCV. We found that this treatment resulted in hepatocellular damage persisting for at least 10 weeks and enabled efficient engraftment and proliferation within the liver of either human or allogenic hepatocytes. Interestingly, while the nodules generated from the transplanted mouse hepatocytes were well vascularized, the human hepatocytes experienced progressive depolarization and exhibited reduced numbers of murine endothelial cells inside the nodules. In conclusion, AdTk/GCV-induced liver damage licenses the liver of immunodeficient mice for allogenic and xenogenic hepatocyte repopulation. This approach represents a simple alternative strategy for chimeric liver generation using immunodeficient mice without additional genetic manipulation of the germ line.

  7. Synergistic toxicity of ethanol and MDMA towards primary cultured rat hepatocytes

    International Nuclear Information System (INIS)

    Pontes, Helena; Sousa, Carla; Silva, Renata; Fernandes, Eduarda; Carmo, Helena; Remiao, Fernando; Carvalho, Felix; Bastos, Maria Lourdes

    2008-01-01

    Ethanol is frequently consumed along with 3,4-methylenedioxymethamphetamine (MDMA; ecstasy). Since both compounds are hepatotoxic and are metabolized in the liver, an increased deleterious interaction resulting from the concomitant use of these two drugs seems plausible. Another important feature of MDMA-induced toxicity is hyperthermia, an effect known to be potentiated after continuous exposure to ethanol. Considering the potential deleterious interaction, the aim of the present study was to evaluate the hepatotoxic effects of ethanol and MDMA mixtures to primary cultured rat hepatocytes and to elucidate the mechanism(s) underlying this interaction. For this purpose, the toxicity induced by MDMA to primary cultured rat hepatocytes in absence or in presence of ethanol was evaluated, under normothermic (36.5 deg. C) and hyperthermic (40.5 deg. C) conditions. While MDMA and ethanol, by themselves, had discrete effects on the analysed parameters, which were slightly aggravated under hyperthermia, the simultaneous incubation of MDMA and ethanol for 24 h, resulted in high cell death ratios accompanied by a significant disturbance of cellular redox status and decreased energy levels. Evaluation of apoptotic/necrotic features provided clear evidences that the cell death occurs preferentially through a necrotic pathway. All the evaluated parameters were dramatically aggravated when cells were incubated under hyperthermia. In conclusion, co-exposure of hepatocytes to ethanol and MDMA definitely results in a synergism of the hepatotoxic effects, through a disruption of the cellular redox status and enhanced cell death by a necrotic pathway in a temperature-dependent extent

  8. Three-dimensional polymer scaffolds for enhanced differentiation of human mesenchymal stem cells to hepatocyte-like cells: a comparative study.

    Science.gov (United States)

    Chitrangi, Swati; Nair, Prabha; Khanna, Aparna

    2017-08-01

    Stem cell-based tissue engineering has emerged as a promising avenue for the treatment of liver diseases and as drug metabolism and toxicity models in drug discovery and development. The in vitro simulation of a micro-environmental niche for hepatic differentiation remains elusive, due to lack of information about crucial factors for the stem cell niche. For generation of functional hepatocytes, an in vivo three-dimensional (3D) micro-environment and architecture should be reproduced. Towards this, we fabricated three scaffolds as dextran-gelatin (DG1), chitosan-hyaluronic acid (CH1) and gelatin-vinyl acetate (GEVAC). Hepatic differentiation of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) was induced by culturing hUC-MSCs on these scaffolds. The scaffolds support hepatic differentiation by mimicking the native extracellular matrix (ECM) micro-environment and architecture to facilitate 3D cell-cell and cell-matrix interactions. The expression of hepatic markers, glycogen storage, urea production, albumin secretion and cytochrome P450 (CYP450) activity indicated the hepatic differentiation of hUC-MSCs. The differentiated hUC-MSCs on the 3D scaffolds formed hepatospheroids (3D hepatocyte aggregates), as illustrated by scanning electron microscopy (SEM), confocal microscopy and cytoskeleton organization. It was observed that the 3D scaffolds supported improved cell morphology, expression of hepatic markers and metabolic activities, as compared to Matrigel-coated plates. To the best of our knowledge, this is the first report demonstrating the use of a well-characterized scaffold (GEVAC) for enhanced differentiation of hUC-MSCs to hepatocyte-like cells (HLCs). Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  9. 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.

  10. GLP-1 analogs reduce hepatocyte steatosis and improve survival by enhancing the unfolded protein response and promoting macroautophagy.

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    Shvetank Sharma

    Full Text Available Nonalcoholic fatty liver disease (NAFLD is a known outcome of hepatosteatosis. Free fatty acids (FFA induce the unfolded protein response (UPR or endoplasmic reticulum (ER stress that may induce apoptosis. Recent data indicate ER stress to be a major player in the progression of fatty liver to more aggressive lesions. Autophagy on the other hand has been demonstrated to be protective against ER stress-induced cell death. We hypothesized that exendin-4 (GLP-1 analog treatment of fat loaded hepatocytes can reduce steatosis by autophagy which leads to reduced ER stress-related hepatocyte apoptosis.Primary human hepatocytes were loaded with saturated, cis- and trans-unsaturated fatty acids (palmitic, oleic and elaidic acid respectively. Steatosis, induced with all three fatty acids, was significantly resolved after exendin-4 treatment. Exendin-4 sustained levels of GRP78 expression in fat-loaded cells when compared to untreated fat-loaded cells alone. In contrast, CHOP (C/EBP homologous protein; the penultimate protein that leads to ER stress-related cell death was significantly decreased by exendin-4 in hepatocytes loaded with fatty acids. Finally, exendin-4 in fat loaded hepatocytes clearly promoted gene products associated with macroautophagy as measured by enhanced production of both Beclin-1 and LC3B-II, markers for autophagy; and visualized by transmission electron microscopy (TEM. Similar observations were made in mouse liver lysates after mice were fed with high fat high fructose diet and treated with a long acting GLP-1 receptor agonist, liraglutide.GLP-1 proteins appear to protect hepatocytes from fatty acid-related death by prohibition of a dysfunctional ER stress response; and reduce fatty acid accumulation, by activation of both macro-and chaperone-mediated autophagy. These findings provide a novel role for GLP-1 proteins in halting the progression of more aggressive lesions from underlying steatosis in humans afflicted with NAFLD.

  11. 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

  12. Flux balance analysis predicts Warburg-like effects of mouse hepatocyte deficient in miR-122a.

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    Hua-Qing Wu

    2017-07-01

    Full Text Available The liver is a vital organ involving in various major metabolic functions in human body. MicroRNA-122 (miR-122 plays an important role in the regulation of liver metabolism, but its intrinsic physiological functions require further clarification. This study integrated the genome-scale metabolic model of hepatocytes and mouse experimental data with germline deletion of Mir122a (Mir122a-/- to infer Warburg-like effects. Elevated expression of MiR-122a target genes in Mir122a-/-mice, especially those encoding for metabolic enzymes, was applied to analyze the flux distributions of the genome-scale metabolic model in normal and deficient states. By definition of the similarity ratio, we compared the flux fold change of the genome-scale metabolic model computational results and metabolomic profiling data measured through a liquid-chromatography with mass spectrometer, respectively, for hepatocytes of 2-month-old mice in normal and deficient states. The Ddc gene demonstrated the highest similarity ratio of 95% to the biological hypothesis of the Warburg effect, and similarity of 75% to the experimental observation. We also used 2, 6, and 11 months of mir-122 knockout mice liver cell to examined the expression pattern of DDC in the knockout mice livers to show upregulated profiles of DDC from the data. Furthermore, through a bioinformatics (LINCS program prediction, BTK inhibitors and withaferin A could downregulate DDC expression, suggesting that such drugs could potentially alter the early events of metabolomics of liver cancer cells.

  13. Chimeric mice transplanted with human hepatocytes as a model for prediction of human drug metabolism and pharmacokinetics.

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    Sanoh, Seigo; Ohta, Shigeru

    2014-03-01

    Preclinical studies in animal models are used routinely during drug development, but species differences of pharmacokinetics (PK) between animals and humans have to be taken into account in interpreting the results. Human hepatocytes are also widely used to examine metabolic activities mediated by cytochrome P450 (P450) and other enzymes, but such in vitro metabolic studies also have limitations. Recently, chimeric mice with humanized liver (h-chimeric mice), generated by transplantation of human donor hepatocytes, have been developed as a model for the prediction of metabolism and PK in humans, using both in vitro and in vivo approaches. The expression of human-specific metabolic enzymes and metabolic activities was confirmed in humanized liver of h-chimeric mice with high replacement ratios, and several reports indicate that the profiles of P450 and non-P450 metabolism in these mice adequately reflect those in humans. Further, the combined use of h-chimeric mice and r-chimeric mice, in which endogenous hepatocytes are replaced with rat hepatocytes, is a promising approach for evaluation of species differences in drug metabolism. Recent work has shown that data obtained in h-chimeric mice enable the semi-quantitative prediction of not only metabolites, but also PK parameters, such as hepatic clearance, of drug candidates in humans, although some limitations remain because of differences in the metabolic activities, hepatic blood flow and liver structure between humans and mice. In addition, fresh h-hepatocytes can be isolated reproducibly from h-chimeric mice for metabolic studies. Copyright © 2013 John Wiley & Sons, Ltd.

  14. Comparison of Species and Cell-Type Differences in Fraction Unbound of Liver Tissues, Hepatocytes, and Cell Lines.

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    Riccardi, Keith; Ryu, Sangwoo; Lin, Jian; Yates, Phillip; Tess, David; Li, Rui; Singh, Dhirender; Holder, Brian R; Kapinos, Brendon; Chang, George; Di, Li

    2018-04-01

    Fraction unbound ( f u ) of liver tissue, hepatocytes, and other cell types is an essential parameter used to estimate unbound liver drug concentration and intracellular free drug concentration. f u,liver and f u,cell are frequently measured in multiple species and cell types in drug discovery and development for various applications. A comparison study of 12 matrices for f u,liver and f u,cell of hepatocytes in five different species (mouse, rat, dog, monkey, and human), as well as f u,cell of Huh7 and human embryonic kidney 293 cell lines, was conducted for 22 structurally diverse compounds with the equilibrium dialysis method. Using an average bioequivalence approach, our results show that the average difference in binding to liver tissue, hepatocytes, or different cell types was within 2-fold of that of the rat f u,liver Therefore, we recommend using rat f u,liver as a surrogate for liver binding in other species and cell types in drug discovery. This strategy offers the potential to simplify binding studies and reduce cost, thereby enabling a more effective and practical determination of f u for liver tissues, hepatocytes, and other cell types. In addition, f u under hepatocyte stability incubation conditions should not be confused with f u,cell , as one is a diluted f u and the other is an undiluted f u Cell density also plays a critical role in the accurate measurement of f u,cell . Copyright © 2018 by The American Society for Pharmacology and Experimental Therapeutics.

  15. Tangeretin and its metabolite 4′-hydroxytetramethoxyflavone attenuate EGF-stimulated cell cycle progression in hepatocytes; role of inhibition at the level of mTOR/p70S6K

    Science.gov (United States)

    Cheng, Z; Surichan, S; Ruparelia, K; Arroo, R; Boarder, MR

    2011-01-01

    BACKGROUND AND PURPOSE The mechanisms by which the dietary compound tangeretin has anticancer effects may include acting as a prodrug, forming an antiproliferative product in cancer cells. Here we show that tangeretin also inhibits cell cycle progression in hepatocytes and investigate the role of its primary metabolite 4′-hydroxy-5,6,7,8-tetramethoxyflavone (4′-OH-TMF) in this effect. EXPERIMENTAL APPROACH We used epidermal growth factor (EGF)-stimulated rat hepatocytes, with [3H]-thymidine incorporation into DNA as an index of progression to S-phase of the cell cycle, and Western blots for phospho-proteins involved in the cell signalling cascade. KEY RESULTS Incubation of tangeretin with microsomes expressing CYP1A, or with hepatocytes, generated a primary product we identified as 4′-OH-TMF. Low micromolar concentrations of tangeretin or 4′-OH-TMF gave a concentration-dependent inhibition of EGF-stimulated progression to S-phase while having little effect on cell viability. To determine whether time for conversion of tangeretin to an active metabolite would enhance the inhibitory effect we used long pre-incubations; this reduced the inhibitory effect, in parallel with a reduction in the concentration of tangeretin. The EGF-stimulation of hepatocyte cell cycle progression requires signalling through Akt/mTOR/p70S6K kinase cascades. The tangeretin metabolite 4′-OH-TMF selectively inhibited S6K phosphorylation in the absence of significant inhibition of upstream Akt activity, suggesting an effect at the level of mTOR. CONCLUSIONS AND IMPLICATIONS Tangeretin and 4′-OH-TMF both inhibit cell cycle progression in primary hepatocytes. The inhibition of p70S6K phosphorylation by 4′-OH-TMF raises the possibility that inhibition of the mTOR pathway may contribute to the anticancer influence of a flavonoid-rich diet. PMID:21198542

  16. An Analysis of the Role and Responsibilities of Chairs of Further Education College and Sixth-Form College Governing Bodies in England

    Science.gov (United States)

    Hill, Ron; James, Chris

    2017-01-01

    This article reports research into the role and responsibilities of the chairs of governing bodies of further education colleges and sixth-form colleges in England. Further education colleges and sixth-form colleges represent a significant part of post-16 educational provision in England. Every college in the sector has a governing body, which has…

  17. Growth hormone-specific induction of the nuclear localization of porcine growth hormone receptor in porcine hepatocytes.

    Science.gov (United States)

    Lan, H N; Hong, P; Li, R N; Shan, A S; Zheng, X

    2017-10-01

    The phenomenon of nuclear translocation of growth hormone receptor (GHR) in human, rat, and fish has been reported. To date, this phenomenon has not been described in a domestic animal (such as pig). In addition, the molecular mechanisms of GHR nuclear translocation have not been thoroughly elucidated. To this end, porcine hepatocytes were isolated and used as a cell model. We observed that porcine growth hormone (pGH) can induce porcine GHR's nuclear localization in porcine hepatocytes. Subsequently, the dynamics of pGH-induced pGHR's nuclear localization were analyzed and demonstrated that pGHR's nuclear localization occurs in a time-dependent manner. Next, we explored the mechanism of pGHR nuclear localization using different pGHR ligands, and we demonstrated that pGHR's nuclear translocation is GH(s)-dependent. We also observed that pGHR translocates into cell nuclei in a pGH dimerization-dependent fashion, whereas further experiments indicated that IMPα/β is involved in the nuclear translocation of the pGH-pGHR dimer. The pGH-pGHR dimer may form a pGH-GHR-JAK2 multiple complex in cell nuclei, which would suggest that similar to its function in the cell membrane, the nuclear-localized pGH-pGHR dimer might still have the ability to signal. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Yeast prions form infectious amyloid inclusion bodies in bacteria

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    Espargaró Alba

    2012-06-01

    Full Text Available Abstract Background Prions were first identified as infectious proteins associated with fatal brain diseases in mammals. However, fungal prions behave as epigenetic regulators that can alter a range of cellular processes. These proteins propagate as self-perpetuating amyloid aggregates being an example of structural inheritance. The best-characterized examples are the Sup35 and Ure2 yeast proteins, corresponding to [PSI+] and [URE3] phenotypes, respectively. Results Here we show that both the prion domain of Sup35 (Sup35-NM and the Ure2 protein (Ure2p form inclusion bodies (IBs displaying amyloid-like properties when expressed in bacteria. These intracellular aggregates template the conformational change and promote the aggregation of homologous, but not heterologous, soluble prionogenic molecules. Moreover, in the case of Sup35-NM, purified IBs are able to induce different [PSI+] phenotypes in yeast, indicating that at least a fraction of the protein embedded in these deposits adopts an infectious prion fold. Conclusions An important feature of prion inheritance is the existence of strains, which are phenotypic variants encoded by different conformations of the same polypeptide. We show here that the proportion of infected yeast cells displaying strong and weak [PSI+] phenotypes depends on the conditions under which the prionogenic aggregates are formed in E. coli, suggesting that bacterial systems might become useful tools to generate prion strain diversity.

  19. Hepatocyte caspase-8 is an essential modulator of steatohepatitis in rodents

    NARCIS (Netherlands)

    Hatting, M.; Zhao, G.; Schumacher, F.; Sellge, G.; Masaoudi, Al M.; Gaßler, N.; Boekschoten, M.V.; Müller, M.R.; Liedtke, C.; Cubero, F.J.; Trautwein, C.

    2013-01-01

    In human and murine models of nonalcoholic steatohepatitis (NASH), increased hepatocyte apoptosis is a critical mechanism contributing to inflammation and fibrogenesis. Caspase 8 (Casp8) is essential for death-receptor-mediated apoptosis activity and therefore its modulation might be critical for

  20. Single-cell analysis of ploidy and centrosomes underscores the peculiarity of normal hepatocytes.

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    Francesca Faggioli

    Full Text Available Polyploidization is the most well recognized feature of the liver. Yet, a quantitative and behavioral analysis of centrosomes and DNA content in normal hepatocytes has been limited by the technical challenges of methods available. By using a novel approach employing FISH for chromosomes 18, X and Y we provide, for the first time, a detailed analysis of DNA copies during physiological development in the liver at single cell level. We demonstrate that aneuploidy and unbalanced DNA content in binucleated hepatocytes are common features in normal adult liver. Despite the common belief that hepatocytes contain 1, 2 or no more than 4 centrosomes, our double staining for centrosome associated proteins reveals extranumerary centrosomes in a high percentage of cells as early as 15 days of age. We show that in murine liver the period between 15 days and 1.5 months marks the transition from a prevalence of mononucleated cells to up to 75% of binucleated cells. Our data demonstrate that this timing correlates with a switch in centrosomes number. At 15 days the expected 1 or 2 centrosomes converge with several hepatocytes that contain 3 centrosomes; at 1.5 months the percentage of cells with 3 centrosomes decreases concomitantly with the increase of cells with more than 4 centrosomes. Our analysis shows that the extranumerary centrosomes emerge in concomitance with the process of binucleation and polyploidization and maintain α-tubulin nucleation activity. Finally, by integrating interphase FISH and immunofluorescent approaches, we detected an imbalance between centrosome number and DNA content in liver cells that deviates from the equilibrium expected in normal cells. We speculate that these unique features are relevant to the peculiar biological function of liver cells which are continuously challenged by stress, a condition that could predispose to genomic instability.

  1. Heme oxygenase-1 prevents non-alcoholic steatohepatitis through suppressing hepatocyte apoptosis in mice

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    Fu Na

    2010-10-01

    Full Text Available Abstract Objective Heme oxygenase-1 (HO-1, the rate-limiting enzyme in heme catabolism, has been reported to have potential antioxidant properties. However, the role of HO-1 on hepatocyte apoptosis remains unclear. We aim to elucidate the effects of HO-1 on oxidative stress related hepatocellular apoptosis in nutritional steatohepatitis in mice. Methods C57BL/6J mice were fed with methionine-choline deficient (MCD diet for four weeks to induce hepatic steatohepatitis. HO-1 chemical inducer (hemin, HO-1 chemical inhibitor zinc protoporphyrin IX (ZnPP-IX and/or adenovirus carrying HO-1 gene (Ad-HO-1 were administered to mice, respectively. Hepatocyte apoptosis was evaluated by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL assay, the mRNA and protein expression of apoptosis related genes were assayed by quantitative real-time PCR and Western blot. Results Hepatocyte signs of oxidative related apoptotic injury were presented in mice fed with MCD diet for 4 weeks. Induction of HO-1 by hemin or Ad-HO-1 significantly attenuated the severity of liver histology, which was associated with decreased hepatic lipid peroxidation content, reduced number of apoptotic cells by TUNEL staining, down-regulated expression of pro-apoptosis related genes including Fas/FasL, Bax, caspase-3 and caspase-9, reduced expression of cytochrome p4502E1 (CYP2E1, inhibited cytochrome c (Cyt-c release, and up-regulated expression of anti-apoptosis gene Bcl-2. Whereas, inhibition of HO-1 by ZnPP-IX caused oxidative stress related hepatic injury, which concomitant with increased number of TUNEL positive cells and up-regulated expression of pro-apoptosis related genes. Conclusions The present study provided evidences for the protective role of HO-1 in preventing nutritional steatohepatitis through suppressing hepatocyte apoptosis in mice.

  2. Cytochrome P450IID6 recognized by LKM1 antibody is not exposed on the surface of hepatocytes.

    Science.gov (United States)

    Yamamoto, A M; Mura, C; De Lemos-Chiarandini, C; Krishnamoorthy, R; Alvarez, F

    1993-06-01

    LKM1 autoantibody, directed against P450IID6, is accepted as a marker of a particular type of autoimmune hepatitis, but its role in the pathogenesis of the disease is controversial. Localization of P450IID6 on the cell surface of rat hepatocytes was previously reported, suggesting that membrane-bound P450IID6 could be the target of LKM1 antibodies, thus allowing immune lysis of hepatocytes. The objective of the present study was to determine, using various methods, the cell localization of P450IID6 in human and rat hepatocytes. Incubation of rat and human hepatocytes with LKM1-positive serum showed slight, if any, cell membrane staining using immunofluorescence, immunoperoxidase and immunoelectron microscopic studies. No staining of the plasma membrane of human hepatocytes was observed when incubations were carried out with immunoaffinity-purified antibody directed against peptide 254-271, the main epitope of P450IID6 recognized by all LKM1 sera tested. Chinese hamster ovary cells, transfected with the complete P450IID6 cDNA and incubated with the supernatant from a B cell lymphoblastoid cell line prepared with the lymphocytes of a LKM1-positive patient, did not show any staining of the cell surface by immunofluorescence. Incubation of rat microsomal fraction vesicles with LKM1-positive serum, followed by protein A-gold immunoelectron microscopy, displayed a staining of almost all vesicles, confirming that P450IID6 is present on the cytoplasmic side of the microsomal membrane, which makes it unable to be expressed on the cell surface even if it were transported from the endoplasmic reticulum (ER). Sulpho NHS Biotin labelling of rat hepatocyte cell membranes did not show the presence of a 50-kD molecule that could have reacted with LKM1 antibody. DNA sequencing of exon 1 of the CYP2D6 gene of a patient positive for LKM1 antibody did not show any difference from that of the normal published sequence of the gene. This does not favour an alteration of the NH2 terminal

  3. A serine palmitoyltransferase inhibitor blocks hepatitis C virus replication in human hepatocytes.

    Science.gov (United States)

    Katsume, Asao; Tokunaga, Yuko; Hirata, Yuichi; Munakata, Tsubasa; Saito, Makoto; Hayashi, Hitohisa; Okamoto, Koichi; Ohmori, Yusuke; Kusanagi, Isamu; Fujiwara, Shinya; Tsukuda, Takuo; Aoki, Yuko; Klumpp, Klaus; Tsukiyama-Kohara, Kyoko; El-Gohary, Ahmed; Sudoh, Masayuki; Kohara, Michinori

    2013-10-01

    Host cell lipid rafts form a scaffold required for replication of hepatitis C virus (HCV). Serine palmitoyltransferases (SPTs) produce sphingolipids, which are essential components of the lipid rafts that associate with HCV nonstructural proteins. Prevention of the de novo synthesis of sphingolipids by an SPT inhibitor disrupts the HCV replication complex and thereby inhibits HCV replication. We investigated the ability of the SPT inhibitor NA808 to prevent HCV replication in cells and mice. We tested the ability of NA808 to inhibit SPT's enzymatic activity in FLR3-1 replicon cells. We used a replicon system to select for HCV variants that became resistant to NA808 at concentrations 4- to 6-fold the 50% inhibitory concentration, after 14 rounds of cell passage. We assessed the ability of NA808 or telaprevir to inhibit replication of HCV genotypes 1a, 1b, 2a, 3a, and 4a in mice with humanized livers (transplanted with human hepatocytes). NA808 was injected intravenously, with or without pegylated interferon alfa-2a and HCV polymerase and/or protease inhibitors. NA808 prevented HCV replication via noncompetitive inhibition of SPT; no resistance mutations developed. NA808 prevented replication of all HCV genotypes tested in mice with humanized livers. Intravenous NA808 significantly reduced viral load in the mice and had synergistic effects with pegylated interferon alfa-2a and HCV polymerase and protease inhibitors. The SPT inhibitor NA808 prevents replication of HCV genotypes 1a, 1b, 2a, 3a, and 4a in cultured hepatocytes and in mice with humanized livers. It might be developed for treatment of HCV infection or used in combination with pegylated interferon alfa-2a or HCV polymerase or protease inhibitors. Copyright © 2013 AGA Institute. Published by Elsevier Inc. All rights reserved.

  4. A characterization of the ZFL cell line and primary hepatocytes as in vitro liver cell models for the zebrafish (Danio rerio)

    International Nuclear Information System (INIS)

    Eide, Marta; Rusten, Marte; Male, Rune; Jensen, Knut Helge Midtbø; Goksøyr, Anders

    2014-01-01

    Highlights: •The ZFL cell line and primary hepatocytes were characterized. •Basic and induced expression of nuclear receptors and target genes were found. •The ZFL cell line expresses very low basic levels of most genes. •The ZFL cells have low induction of gene expression following exposures. •Primary hepatocytes show large sex-dependent differences in gene expression. -- Abstract: The zebrafish (Danio rerio) is a widely used model species in biomedical research. The ZFL cell line, established from zebrafish liver, and freshly isolated primary hepatocytes from zebrafish have been used in several toxicological studies. However, no previous report has compared and characterized these two systems at the level of gene expression. The aim of this study was to evaluate the ZFL cell line in comparison to primary hepatocytes as in vitro models for studying effects of environmental contaminants in zebrafish liver. Using quantitative real-time PCR, the basal level and transcriptional induction potential of key genes involved in toxic responses in the ZFL cell line, primary hepatocytes and whole liver from zebrafish were compared. The study showed that the ZFL cells have lower levels of mRNA of most selected genes compared to zebrafish liver. The induced gene transcription following exposure to ligand was much lower in ZFL cells compared to zebrafish primary hepatocytes at the doses tested. Importantly, oestrogen receptor and vitellogenin genes showed low basal transcription and no induction response in the ZFL cell line. In conclusion, it appears that primary hepatocytes are well suited for studying environmental contaminants including xenoestrogens, but may show large sex-dependent differences in gene transcription. The ZFL cell line shows potential in toxicological studies involving the aryl hydrocarbon receptor pathway. However, low potential for transcriptional induction of genes in general should be expected, especially notable when studying estrogenic

  5. A characterization of the ZFL cell line and primary hepatocytes as in vitro liver cell models for the zebrafish (Danio rerio)

    Energy Technology Data Exchange (ETDEWEB)

    Eide, Marta, E-mail: marta.eide@bio.uib.no [Department of Biology, University of Bergen, Bergen (Norway); Rusten, Marte; Male, Rune [Department of Molecular Biology, University of Bergen, Bergen (Norway); Jensen, Knut Helge Midtbø; Goksøyr, Anders [Department of Biology, University of Bergen, Bergen (Norway)

    2014-02-15

    Highlights: •The ZFL cell line and primary hepatocytes were characterized. •Basic and induced expression of nuclear receptors and target genes were found. •The ZFL cell line expresses very low basic levels of most genes. •The ZFL cells have low induction of gene expression following exposures. •Primary hepatocytes show large sex-dependent differences in gene expression. -- Abstract: The zebrafish (Danio rerio) is a widely used model species in biomedical research. The ZFL cell line, established from zebrafish liver, and freshly isolated primary hepatocytes from zebrafish have been used in several toxicological studies. However, no previous report has compared and characterized these two systems at the level of gene expression. The aim of this study was to evaluate the ZFL cell line in comparison to primary hepatocytes as in vitro models for studying effects of environmental contaminants in zebrafish liver. Using quantitative real-time PCR, the basal level and transcriptional induction potential of key genes involved in toxic responses in the ZFL cell line, primary hepatocytes and whole liver from zebrafish were compared. The study showed that the ZFL cells have lower levels of mRNA of most selected genes compared to zebrafish liver. The induced gene transcription following exposure to ligand was much lower in ZFL cells compared to zebrafish primary hepatocytes at the doses tested. Importantly, oestrogen receptor and vitellogenin genes showed low basal transcription and no induction response in the ZFL cell line. In conclusion, it appears that primary hepatocytes are well suited for studying environmental contaminants including xenoestrogens, but may show large sex-dependent differences in gene transcription. The ZFL cell line shows potential in toxicological studies involving the aryl hydrocarbon receptor pathway. However, low potential for transcriptional induction of genes in general should be expected, especially notable when studying estrogenic

  6. Improved Survival and Initiation of Differentiation of Human Induced Pluripotent Stem Cells to Hepatocyte-Like Cells upon Culture in William's E Medium followed by Hepatocyte Differentiation Inducer Treatment.

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    Minoru Tomizawa

    Full Text Available Hepatocyte differentiation inducer (HDI lacks both glucose and arginine, but is supplemented with galactose and ornithine, and is added together with other reagents such as apoptosis inhibitor and oncostatin M. Although human induced pluripotent stem (iPS cells initiate hepatocyte differentiation, most die within 7 days. In this study, we investigated both HDI and conventional media for their potential to improve cell survival.201B7 iPS cells were cultured in conventional media. This consisted of three cycles of 5-day culture in William's E (WE medium, followed by a 2-day culture in HDI.Expression levels of α-feto protein (AFP were higher in cells cultured in WE and in Dulbecco's Modified Eagle's Medium/Nutrient F-12 Ham (DF12. 201B7 cells expressed the highest AFP and albumin (ALB when cultured in HDI for 2 days following 7-day culture in WE. After three cycles of 5-day culture in WE followed by 2 days in HDI, 201B7 cells expressed AFP and ALB 54 ± 2.3 (average ± standard deviation and 73 ± 15.1 times higher, respectively, than those cultured in ReproFF (feeder-free condition.201B7 cells survived culture in WE for 7 days followed HDI for 2 days. After three cycles of culture under these conditions, hepatocyte differentiation was enhanced, as evidenced by increased AFP and ALB expression.

  7. Effects of human pharmaceuticals on cytotoxicity, EROD activity and ROS production in fish hepatocytes

    International Nuclear Information System (INIS)

    Laville, N.; Aiet-Aiessa, S.; Gomez, E.; Casellas, C.; Porcher, J.M.

    2004-01-01

    Pharmaceuticals are found in the aquatic environment but their potential effects on non-target species like fish remain unknown. This in vitro study is a first approach in the toxicity assessment of human drugs on fish. Nine pharmaceuticals were tested on two fish hepatocyte models: primary cultures of rainbow trout hepatocytes (PRTH) and PLHC-1 fish cell line. Cell viability, interaction with cytochrome P450 1A (CYP1A) enzyme and oxidative stress were assessed by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrasodium bromide tetrazolium (MTT), 7-ethoxyresorufin-o-deethylase (EROD) and dichlorofluorescein (DCFH-DA) assays, respectively. The tested drugs were clofibrate (CF), fenofibrate (FF), carbamazepine (CBZ), fluoxetine (FX), diclofenac (DiCF), propranolol (POH), sulfamethoxazole (SFX), amoxicillin (AMX) and gadolinium chloride (GdCl 3 ). All substances were cytotoxic, except AMX at concentration up to 500 μM. The calculated MTT EC 50 values ranged from 2 μM (CF) to 651 μM (CBZ) in PLHC-1, and from 53 μM (FF) to 962 μM (GdCl 3 ) in PRTH. CF, FF, and FX were the most cytotoxic drugs and induced oxidative stress before being cytotoxic. Compared to hepatocytes from human and dog, fish hepatocytes seemed to be more susceptible to the peroxisome proliferators (PPs) CF and FF. In PLHC-1 cells none of the tested drugs induced the EROD activity whereas POH appeared as a weak EROD inducer in PRTH. Moreover, in PRTH, SFX, DiCF, CBZ and to a lesser extend, FF and CF inhibited the basal EROD activity at clearly sublethal concentrations which may be of concern at the biological and chemical levels in a multipollution context

  8. Berberine Protects against NEFA-Induced Impairment of Mitochondrial Respiratory Chain Function and Insulin Signaling in Bovine Hepatocytes

    Directory of Open Access Journals (Sweden)

    Zhen Shi

    2018-06-01

    Full Text Available Fatty liver is a major lipid metabolic disease in perinatal dairy cows and is characterized by high blood levels of non-esterified fatty acid (NEFA and insulin resistance. Berberine (BBR has been reported to improve insulin sensitivity in mice with hepatic steatosis. Mitochondrial dysfunction is considered a causal factor that induces insulin resistance. This study investigates the underlying mechanism and the beneficial effects of BBR on mitochondrial and insulin signaling in bovine hepatocytes. Revised quantitative insulin sensitivity check index (RQUICKI of cows with fatty liver was significantly lower than that of healthy cows. Importantly, the Akt and GSK3β phosphorylation levels, protein levels of PGC-1α and four of the five representative subunits of oxidative phosphorylation (OXPHOS were significantly decreased in cows with fatty liver using Western Blot analysis. In bovine hepatocytes, 1.2 mmol/L NEFA reduced insulin signaling and mitochondrial respiratory chain function, and 10 and 20 umol/L BBR restored these changes. Furthermore, activation of PGC-1α played the same beneficial effects of BBR on hepatocytes treated with NEFA. BBR treatment improves NEFA-impaired mitochondrial respiratory chain function and insulin signaling by increasing PGC-1α expression in hepatocytes, which provides a potential new strategy for the prevention and treatment of fatty liver in dairy cows.

  9. Effect of guava (Psidium guajava L.) leaf extract on glucose uptake in rat hepatocytes.

    Science.gov (United States)

    Cheng, Fang-Chi; Shen, Szu-Chuan; Wu, James Swi-Bea

    2009-06-01

    People in oriental countries, including Japan and Taiwan, boil guava leaves (Psidium guajava L.) in water and drink the extract as a folk medicine for diabetes. The present study investigated the enhancement of aqueous guava leaf extract on glucose uptake in rat clone 9 hepatocytes and searched for the active compound. The extract was eluted with MeOH-H(2)O solutions through Diaion, Sephadex, and MCI-gel columns to separate into fractions with different polarities. The uptake test of 2-[1-(14)C] deoxy-D-glucose in rat clone 9 hepatocytes was performed to evaluate the hypoglycemic effect of these fractions. The active compound was identified by nuclear magnetic resonance analysis and high-performance liquid chromatography (HPLC). The results revealed that phenolics are the principal component of the extract, that high polarity fractions of the guava leaf extract are enhancers to glucose uptake in rat clone 9 hepatocytes, and that quercetin is the major active compound. We suggest that quercetin in the aqueous extract of guava leaves promotes glucose uptake in liver cells, and contributes to the alleviation of hypoglycemia in diabetes as a consequence.

  10. Ultrastructure of hepatocyte nuclei in irradiated, adrenalectomized rats

    Energy Technology Data Exchange (ETDEWEB)

    Orkisz, S.; Bartel, H.; Kmiec, B. (Military Medical Academy, Lodz (Poland))

    1984-01-01

    A cytochemical study of hepatocyte nuclei of adrenalectomized and irradiated rats was performed. After irradiation alone, the behaviour of the ribonucleoprotein components was studied according to Bernhard. The findings suggest that a delay occurs in the synthesis of preribosomal RNA in the nucleoli and in the transport of messenger RNA to the cytoplasm. The indirect effect of ionizing radiation on nuclear RNA synthesis is assumed to occur through the influence of cortical steroid hormones on the transcription process.

  11. Mitochondrial protein adducts formation and mitochondrial dysfunction during N-acetyl-m-aminophenol (AMAP)-induced hepatotoxicity in primary human hepatocytes

    International Nuclear Information System (INIS)

    Xie, Yuchao; McGill, Mitchell R.; Du, Kuo; Dorko, Kenneth; Kumer, Sean C.; Schmitt, Timothy M.; Ding, Wen-Xing; Jaeschke, Hartmut

    2015-01-01

    3′-Hydroxyacetanilide or N-acetyl-meta-aminophenol (AMAP) is generally regarded as a non-hepatotoxic analog of acetaminophen (APAP). Previous studies demonstrated the absence of toxicity after AMAP in mice, hamsters, primary mouse hepatocytes and several cell lines. In contrast, experiments with liver slices suggested that it may be toxic to human hepatocytes; however, the mechanism of toxicity is unclear. To explore this, we treated primary human hepatocytes (PHH) with AMAP or APAP for up to 48 h and measured several parameters to assess metabolism and injury. Although less toxic than APAP, AMAP dose-dependently triggered cell death in PHH as indicated by alanine aminotransferase (ALT) release and propidium iodide (PI) staining. Similar to APAP, AMAP also significantly depleted glutathione (GSH) in PHH and caused mitochondrial damage as indicated by glutamate dehydrogenase (GDH) release and the JC-1 assay. However, unlike APAP, AMAP treatment did not cause relevant c-jun-N-terminal kinase (JNK) activation in the cytosol or phospho-JNK translocation to mitochondria. To compare, AMAP toxicity was assessed in primary mouse hepatocytes (PMH). No cytotoxicity was observed as indicated by the lack of lactate dehydrogenase release and no PI staining. Furthermore, there was no GSH depletion or mitochondrial dysfunction after AMAP treatment in PMH. Immunoblotting for arylated proteins suggested that AMAP treatment caused extensive mitochondrial protein adduct formation in PHH but not in PMH. In conclusion, AMAP is hepatotoxic in PHH and the mechanism involves the formation of mitochondrial protein adducts and mitochondrial dysfunction. - Highlights: • AMAP induces cell death in primary human hepatocytes (PHH). • AMAP does not cause cell death in primary mouse hepatocytes (PMH). • AMAP leads to mitochondria dysfunction in PHH but not PMH. • Protein adduct formation and dysfunction in mitochondria correlate with toxicity.

  12. Mitochondrial protein adducts formation and mitochondrial dysfunction during N-acetyl-m-aminophenol (AMAP)-induced hepatotoxicity in primary human hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Yuchao; McGill, Mitchell R.; Du, Kuo; Dorko, Kenneth [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160 (United States); Kumer, Sean C.; Schmitt, Timothy M. [Department of Surgery, University of Kansas Medical Center, Kansas City, KS 66160 (United States); Ding, Wen-Xing [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160 (United States); Jaeschke, Hartmut, E-mail: hjaeschke@kumc.edu [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160 (United States)

    2015-12-01

    3′-Hydroxyacetanilide or N-acetyl-meta-aminophenol (AMAP) is generally regarded as a non-hepatotoxic analog of acetaminophen (APAP). Previous studies demonstrated the absence of toxicity after AMAP in mice, hamsters, primary mouse hepatocytes and several cell lines. In contrast, experiments with liver slices suggested that it may be toxic to human hepatocytes; however, the mechanism of toxicity is unclear. To explore this, we treated primary human hepatocytes (PHH) with AMAP or APAP for up to 48 h and measured several parameters to assess metabolism and injury. Although less toxic than APAP, AMAP dose-dependently triggered cell death in PHH as indicated by alanine aminotransferase (ALT) release and propidium iodide (PI) staining. Similar to APAP, AMAP also significantly depleted glutathione (GSH) in PHH and caused mitochondrial damage as indicated by glutamate dehydrogenase (GDH) release and the JC-1 assay. However, unlike APAP, AMAP treatment did not cause relevant c-jun-N-terminal kinase (JNK) activation in the cytosol or phospho-JNK translocation to mitochondria. To compare, AMAP toxicity was assessed in primary mouse hepatocytes (PMH). No cytotoxicity was observed as indicated by the lack of lactate dehydrogenase release and no PI staining. Furthermore, there was no GSH depletion or mitochondrial dysfunction after AMAP treatment in PMH. Immunoblotting for arylated proteins suggested that AMAP treatment caused extensive mitochondrial protein adduct formation in PHH but not in PMH. In conclusion, AMAP is hepatotoxic in PHH and the mechanism involves the formation of mitochondrial protein adducts and mitochondrial dysfunction. - Highlights: • AMAP induces cell death in primary human hepatocytes (PHH). • AMAP does not cause cell death in primary mouse hepatocytes (PMH). • AMAP leads to mitochondria dysfunction in PHH but not PMH. • Protein adduct formation and dysfunction in mitochondria correlate with toxicity.

  13. Hepatocyte DACH1 Is Increased in Obesity via Nuclear Exclusion of HDAC4 and Promotes Hepatic Insulin Resistance

    Directory of Open Access Journals (Sweden)

    Lale Ozcan

    2016-06-01

    Full Text Available Defective insulin signaling in hepatocytes is a key factor in type 2 diabetes. In obesity, activation of calcium/calmodulin-dependent protein kinase II (CaMKII in hepatocytes suppresses ATF6, which triggers a PERK-ATF4-TRB3 pathway that disrupts insulin signaling. Elucidating how CaMKII suppresses ATF6 is therefore essential to understanding this insulin resistance pathway. We show that CaMKII phosphorylates and blocks nuclear translocation of histone deacetylase 4 (HDAC4. As a result, HDAC4-mediated SUMOylation of the corepressor DACH1 is decreased, which protects DACH1 from proteasomal degradation. DACH1, together with nuclear receptor corepressor (NCOR, represses Atf6 transcription, leading to activation of the PERK-TRB3 pathway and defective insulin signaling. DACH1 is increased in the livers of obese mice and humans, and treatment of obese mice with liver-targeted constitutively nuclear HDAC4 or DACH1 small hairpin RNA (shRNA increases ATF6, improves hepatocyte insulin signaling, and protects against hyperglycemia and hyperinsulinemia. Thus, DACH1-mediated corepression in hepatocytes emerges as an important link between obesity and insulin resistance.

  14. Metabolism of lysergic acid diethylamide (LSD) to 2-oxo-3-hydroxy LSD (O-H-LSD) in human liver microsomes and cryopreserved human hepatocytes.

    Science.gov (United States)

    Klette, K L; Anderson, C J; Poch, G K; Nimrod, A C; ElSohly, M A

    2000-10-01

    The metabolism of lysergic acid diethylamide (LSD) to 2-oxo-3-hydroxy lysergic acid diethylamide (O-H-LSD) was investigated in liver microsomes and cyropreserved hepatocytes from humans. Previous studies have demonstrated that O-H-LSD is present in human urine at concentrations 16-43 times greater than LSD, the parent compound. Additionally, these studies have determined that O-H-LSD is not generated during the specimen extraction and analytical processes or due to parent compound degradation in aqueous urine samples. However, these studies have not been conclusive in demonstrating that O-H-LSD is uniquely produced during in vivo metabolism. Phase I drug metabolism was investigated by incubating human liver microsomes and cryopreserved human hepatocytes with LSD. The reaction was quenched at various time points, and the aliquots were extracted using liquid partitioning and analyzed by liquid chromatography-mass spectrometry. O-H-LSD was positively identified in all human liver microsomal and human hepatocyte fractions incubated with LSD. In addition, O-H-LSD was not detected in any microsomal or hepatocyte fraction not treated with LSD nor in LSD specimens devoid of microsomes or hepatocytes. This study provides definitive evidence that O-H-LSD is produced as a metabolic product following incubation of human liver microsomes and hepatocytes with LSD.

  15. HCO3(-)-coupled Na+ influx is a major determinant of Na+ turnover and Na+/K+ pump activity in rat hepatocytes

    International Nuclear Information System (INIS)

    Fitz, J.G.; Lidofsky, S.D.; Weisiger, R.A.; Xie, M.H.; Cochran, M.; Grotmol, T.; Scharschmidt, B.F.

    1991-01-01

    Recent studies in hepatocytes indicate that Na(+)-coupled HCO3- transport contributes importantly to regulation of intracellular pH and membrane HCO3- transport. However, the direction of net coupled Na+ and HCO3- movement and the effect of HCO3- on Na+ turnover and Na+/K+ pump activity are not known. In these studies, the effect of HCO3- on Na+ influx and turnover were measured in primary rat hepatocyte cultures with 22Na+, and [Na+]i was measured in single hepatocytes using the Na(+)-sensitive fluorochrome SBFI. Na+/K+ pump activity was measured in intact perfused rat liver and hepatocyte monolayers as Na(+)-dependent or ouabain-suppressible 86Rb uptake, and was measured in single hepatocytes as the effect of transient pump inhibition by removal of extracellular K+ on membrane potential difference (PD) and [Na+]i. In hepatocyte monolayers, HCO3- increased 22Na+ entry and turnover rates by 50-65%, without measurably altering 22Na+ pool size or cell volume, and HCO3- also increased Na+/K+ pump activity by 70%. In single cells, exposure to HCO3- produced an abrupt and sustained rise in [Na+]i from approximately 8 to 12 mM. Na+/K+ pump activity assessed in single cells by PD excursions during transient K+ removal increased congruent to 2.5-fold in the presence of HCO3-, and the rise in [Na+]i produced by inhibition of the Na+/K+ pump was similarly increased congruent to 2.5-fold in the presence of HCO3-. In intact perfused rat liver, HCO3- increased both Na+/K+ pump activity and O2 consumption. These findings indicate that, in hepatocytes, net coupled Na+ and HCO3- movement is inward and represents a major determinant of Na+ influx and Na+/K+ pump activity. About half of hepatic Na+/K+ pump activity appears dedicated to recycling Na+ entering in conjunction with HCO3- to maintain [Na+]i within the physiologic range

  16. Organization of the lamin scaffold in the internal nuclear matrix of normal and transformed hepatocytes

    International Nuclear Information System (INIS)

    Barboro, Paola; D'Arrigo, Cristina; Repaci, Erica; Patrone, Eligio; Balbi, Cecilia

    2010-01-01

    Nuclear lamins are among the more abundant proteins making up the internal nuclear matrix, but very little is known about their structure in the nucleoplasm. Using immunoelectron microscopy, we demonstrate the organization of lamins in the nuclear matrix isolated from rat hepatocytes for the first time. Lamin epitopes are arrayed both in locally ordered clusters and in quasi-regular rows. Fourier filtering of the images demonstrates that the epitopes are placed at the nodes and halfway between the nodes of square or rhombic lattices that are about 50 nm on each side, as well as along rows at regular ∼25-nm intervals. In addition, we have compared this structure with that of the internal nuclear matrix isolated from persistent hepatocyte nodules. In transformed hepatocytes, the islands of lamin lattice are lost, and only a partial regularity in the rows of gold particles remains. We suggest that orthogonal lattice assembly might be an intrinsic property of lamin molecules, and that the disassembly may be triggered by simple molecular events such as phosphorylation.

  17. Dynamic Network Reconstruction from Gene Expression Data Describing the Effect of LiCl Stimulation on Hepatocytes

    Directory of Open Access Journals (Sweden)

    Zellmer Sebastian

    2005-12-01

    Full Text Available Wnt/β-catenin signalling plays an important role in zonation of liver parenchyma and in patterning of hepatocyte heterogeneity. A characteristic marker of this heterogeneity is glutamine synthetase, which is expressed only in a subset of pericentrally located hepatocytes. To investigate, whether and how the Wnt/β-catenin signalling pathway is involved a culture of hepatocytes was stimulated by LiCl. This resulted in an increase in the specific GS activity, indicating that the Wnt/β-catenin pathway may participate in regulating GS levels. Affymetrix GeneChip oligonucleotide arrays were used to monitor the gene expression changes during a period from 2 to 24 hours after stimulation by LiCl. Samples from a cultivation without stimulation were used as controls. Based on the gene expression profiles a hypothetic signal transduction network was constructed by a reverse engineering algorithm. The network robustness was tested and the most stable structure was identified.

  18. SELENIUM MODIFIES THE METABOLISM AND TOXICITY OF ARSENIC IN PRIMARY RAT HEPATOCYTES

    Science.gov (United States)

    ABSTRACTSelenium Modifies the Metabolism and Toxicity of Arsenic in Primary Rat Hepatocytes. Miroslav Styblo, David J. Thomas (2000) Toxicol. Appl. Pharmacol. Arsenic and selenium are metalloids with similar chemical properties and metabolic fates. Inorganic arsenic (iAs...

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

    Directory of Open Access Journals (Sweden)

    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.

  20. Liver/kidney microsomal antibody type 1 targets CYP2D6 on hepatocyte plasma membrane.

    Science.gov (United States)

    Muratori, L; Parola, M; Ripalti, A; Robino, G; Muratori, P; Bellomo, G; Carini, R; Lenzi, M; Landini, M P; Albano, E; Bianchi, F B

    2000-04-01

    Liver/kidney microsomal antibody type 1 (LKM1) is the marker of type 2 autoimmune hepatitis (AIH) and is detected in up to 6% of patients with hepatitis C virus (HCV) infection. It recognises linear and conformational epitopes of cytochrome P450IID6 (CYP2D6) and may have liver damaging activity, provided that CYP2D6 is accessible to effector mechanisms of autoimmune attack. The presence of LKM1 in the plasma membrane was investigated by indirect immunofluorescence and confocal laser microscopy of isolated rat hepatocytes probed with 10 LKM1 positive sera (five from patients with AIH and five from patients with chronic HCV infection) and a rabbit polyclonal anti-CYP2D6 serum. Serum from both types of patient stained the plasma membrane of non-permeabilised cells, where the fluorescent signal could be visualised as discrete clumps. Conversely, permeabilised hepatocytes showed diffuse submembranous/cytoplasmic staining. Adsorption with recombinant CYP2D6 substantially reduced plasma membrane staining and LKM1 immunoblot reactivity. Plasma membrane staining of LKM1 colocalised with that of anti-CYP2D6. Immunoprecipitation experiments showed that a single 50 kDa protein recognised by anti-CYP2D6 can be isolated from the plasma membrane of intact hepatocytes. AIH and HCV related LKM1 recognise CYP2D6 exposed on the plasma membrane of isolated hepatocytes. This observation supports the notion that anti-CYP2D6 autoreactivity may be involved in the pathogenesis of liver damage.

  1. FY 2000 report on the results of the regional consortium R and D project - Regional new technology creation R and D. First year report. R and D of medicine toxicity assessment use hepatocyte chip; 2000 nendo chiiki consortium kenkyu kaihatsu jigyo. Chiiki consortium kenkyu kaihatsu / chiiki shingijutsu soshutsu kenkyu kaihatsu. Dokubutsu dokusei hyokayo kansaibo chip no kenkyu kaihatsu (dai 1 nendo) seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    Judging that in the beginning of the toxicity test, the necessary information/knowledge are acquired not by using animal itself but only by using liver system (hepatocyte), the development was proceeded with of the hepatocyte chip substituting for the animal experiment. Studies were made in the following five fields: 1) design of functional matrices; 2) development of the pharmacological assessment technology; 3) development of cell sensing technology/biosensor fabrication; 4) study of a possibility and the limit of cell patterning technology; 5) survey of the market scale. In 1), studies were made of the establishment of the 3D culture method for hepatocyte and the construction of hepatocyte models for medicine assessment using pieces of liver. In the latter, by including capsule using the sugar introduced with galactose residue which is special sugar of hepatocyte to alginic acid and chitosan which are natural polymer and also hepatocyte isolated into sponge, aggregate was formed, and its use as a medicine assessment use liver model was tried to be made. (NEDO)

  2. Dose Response of Endotoxin on Hepatocyte and Muscle Mitochondrial Respiration In Vitro

    Science.gov (United States)

    Brandt, Sebastian; Porta, Francesca; Jakob, Stephan M.; Takala, Jukka; Djafarzadeh, Siamak

    2015-01-01

    Introduction. Results on mitochondrial dysfunction in sepsis are controversial. We aimed to assess effects of LPS at wide dose and time ranges on hepatocytes and isolated skeletal muscle mitochondria. Methods. Human hepatocellular carcinoma cells (HepG2) were exposed to placebo or LPS (0.1, 1, and 10 μg/mL) for 4, 8, 16, and 24 hours and primary human hepatocytes to 1 μg/mL LPS or placebo (4, 8, and 16 hours). Mitochondria from porcine skeletal muscle samples were exposed to increasing doses of LPS (0.1–100 μg/mg) for 2 and 4 hours. Respiration rates of intact and permeabilized cells and isolated mitochondria were measured by high-resolution respirometry. Results. In HepG2 cells, LPS reduced mitochondrial membrane potential and cellular ATP content but did not modify basal respiration. Stimulated complex II respiration was reduced time-dependently using 1 μg/mL LPS. In primary human hepatocytes, stimulated mitochondrial complex II respiration was reduced time-dependently using 1 μg/mL LPS. In isolated porcine skeletal muscle mitochondria, stimulated respiration decreased at high doses (50 and 100 μg/mL LPS). Conclusion. LPS reduced cellular ATP content of HepG2 cells, most likely as a result of the induced decrease in membrane potential. LPS decreased cellular and isolated mitochondrial respiration in a time-dependent, dose-dependent and complex-dependent manner. PMID:25649304

  3. Evaluation of Medicinal Plant Hepatotoxicity in Co-cultures of Hepatocytes and Monocytes

    Directory of Open Access Journals (Sweden)

    Bashar Saad

    2006-01-01

    Full Text Available Non-parenchymal cells might play an important role in the modulation of xenobiotic metabolism in liver and its pharmacological and toxicological consequences. Therefore, the role of cell-to-cell interactions in herbal induced liver toxicity was investigated in monocultures of cells from the human hepatocyte cell line (HepG2 and in co-cultures of cells from the HepG2 cell line and cells from the human monocyte cell line (THP1. Cells were treated with various concentrations (1–500 µg ml−1 of extracts of Pistacia palaestina, Juglans regia and Quercus ithaburensis for 24 h. Extracts from Cleome droserifolia, a known toxic plant, were taken as positive control. In the co-culture system, toxic effects were observed after exposure to extracts of Pistacia palestina and C. droserifolia. These two extracts significantly reduced by cell viability as measured the MTT test and the LDH assay. Whereas in hepatocyte cultures, only extracts of C. droserifolia were found to affect the cell viability. The production levels of albumin from hepatocytes were not affected by treatment with plant extracts in both culture systems. It seems that the observed reduction in cell viability after exposure to extracts of P. palestina in co-cultures but not in monocultures is a result of monocyte-derived factors. The use of liver cell co-cultures is therefore a useful approach to investigate the influence of intercellular communication on xenobiotic metabolism in liver.

  4. Hepatocyte growth factor profile with breast cancer

    Directory of Open Access Journals (Sweden)

    Hoda A EL-Attar

    2011-01-01

    Full Text Available Background: The multifunctional hepatocyte growth factor (HGF is the ligand of c-Met receptor; it plays important role in mammary differentiation. HGF-Met signaling is a critical downstream function of c-Src-Stat3 pathway in mammalian tumorigenesis. Aim: Evaluation of tissue c-Met receptor hepatocyte growth factor receptor (HGFR and serum level of HGF in female breast ductal carcinoma. Materials and Methods: Sixty-eight premenopausal females were divided as 30 control females subdivided into: [Group 1] 15 healthy volunteer females and [Group 2] five with fibrocystic disease and 10 having fibroadenoma of the breast and patients group [Group 3] consisted of 38 female patients with breast ductal carcinoma. Thorough clinical examination, preoperative fine needle aspiration cytology, estimation of fasting serum glucose, urea, creatinine, and uric acid levels, alanine aminotransferase activities, C-reactive protein, HGF level, before surgery and histopathological examination of the breast masses, and immunohistochemical detection of HGFR were done. Results and Conclusions: Significant increase in serum HGF levels were found in patients with breast cancer as compared with controls. Significant increase was also seen in patients with breast cancer with and without lymph node metastasis when each subgroup was compared with controls. Serum level of HGF is an independent prognostic indicator of breast cancer. Fibrocystic disease of the breast showed weak HGFR expression, while in normal tissue, HGFR was scanty; meanwhile, breast invasive ductal carcinoma showed homogenous strong reaction to HGFR. HGF is only one of a number of key factors involved in breast cancer and preoperative high serum HGF levels and malignancy occur usually together.

  5. The effects of gender, age, ethnicity, and liver cirrhosis on cytochrome P450 enzyme activity in human liver microsomes and inducibility in cultured human hepatocytes

    International Nuclear Information System (INIS)

    Parkinson, Andrew; Mudra, Daniel R.; Johnson, Cory; Dwyer, Anne; Carroll, Kathleen M.

    2004-01-01

    We have measured cytochrome P450 (CYP) activity in nearly 150 samples of human liver microsomes and 64 samples of cryopreserved human hepatocytes, and we have performed induction studies in over 90 preparations of cultured human hepatocytes. We have analyzed these data to examine whether the expression of CYP enzyme activity in liver microsomes and isolated hepatocytes or the inducibility of CYP enzymes in cultured hepatocytes is influenced by the gender, age, or ethnicity of the donor (the latter being limited to Caucasians, African Americans, and Hispanics due to a paucity of livers from Asian donors). In human liver microsomes, there were no statistically significant differences (P > 0.05) in CYP activity as a function of age, gender, or ethnicity with one exception. 7-Ethoxyresorufin O-dealkylase (CYP1A2) activity was greater in males than females, which is consistent with clinical observation. Liver microsomal testosterone 6β-hydroxylase (CYP3A4) activity was slightly greater in females than males, but the difference was not significant. However, in cryopreserved human hepatocytes, the gender difference in CYP3A4 activity (females = twice males) did reach statistical significance, which supports the clinical observation that females metabolize certain CYP3A4 substrates faster than do males. Compared with those from Caucasians and African Americans, liver microsomes from Hispanics had about twice the average activity of CYP2A6, CYP2B6, and CYP2C8 and half the activity of CYP1A2, although this apparent ethnic difference may be a consequence of the relatively low number of Hispanic donors. Primary cultures of hepatocytes were treated with β-naphthoflavone, an inducer of CYP1A2, phenobarbital or rifampin, both of which induce CYP2B6, CYP2C9, CYP2C19, and CYP3A4, albeit it to different extents. Induction of these CYP enzymes in freshly cultured hepatocytes did not appear to be influenced by the gender or age of the donor. Furthermore, CYP3A4 induction in

  6. [Crabtree effect caused by ketoses in isolated rat hepatocytes].

    Science.gov (United States)

    Martínez, P; Carrascosa, J M; Núñez de Castro, I

    1982-01-01

    Oxygen uptake and glycolytic activity were studied in hepatocytes isolated from fed rats. The addition of fructose or tagatose resulted in a 38% and 31% inhibition of cellular respiration respectively. The addition of 10 mM D-glyceraldehyde caused a slight Crabtree effect. Glucose, L-sorbose, or glycerol failed to modify oxygen consumption. Only incubation in the presence of fructose showed a high aerobic glycolysis measured by lactate production.

  7. A pump-free microfluidic 3D perfusion platform for the efficient differentiation of human hepatocyte-like cells.

    Science.gov (United States)

    Ong, Louis Jun Ye; Chong, Lor Huai; Jin, Lin; Singh, Pawan Kumar; Lee, Poh Seng; Yu, Hanry; Ananthanarayanan, Abhishek; Leo, Hwa Liang; Toh, Yi-Chin

    2017-10-01

    The practical application of microfluidic liver models for in vitro drug testing is partly hampered by their reliance on human primary hepatocytes, which are limited in number and have batch-to-batch variation. Human stem cell-derived hepatocytes offer an attractive alternative cell source, although their 3D differentiation and maturation in a microfluidic platform have not yet been demonstrated. We develop a pump-free microfluidic 3D perfusion platform to achieve long-term and efficient differentiation of human liver progenitor cells into hepatocyte-like cells (HLCs). The device contains a micropillar array to immobilize cells three-dimensionally in a central cell culture compartment flanked by two side perfusion channels. Constant pump-free medium perfusion is accomplished by controlling the differential heights of horizontally orientated inlet and outlet media reservoirs. Computational fluid dynamic simulation is used to estimate the hydrostatic pressure heads required to achieve different perfusion flow rates, which are experimentally validated by micro-particle image velocimetry, as well as viability and functional assessments in a primary rat hepatocyte model. We perform on-chip differentiation of HepaRG, a human bipotent progenitor cell, and discover that 3D microperfusion greatly enhances the hepatocyte differentiation efficiency over static 2D and 3D cultures. However, HepaRG progenitor cells are highly sensitive to the time-point at which microperfusion is applied. Isolated HepaRG cells that are primed as static 3D spheroids before being subjected to microperfusion yield a significantly higher proportion of HLCs (92%) than direct microperfusion of isolated HepaRG cells (62%). This platform potentially offers a simple and efficient means to develop highly functional microfluidic liver models incorporating human stem cell-derived HLCs. Biotechnol. Bioeng. 2017;114: 2360-2370. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  8. Oxygen dependency of epidermal growth factor receptor binding and DNA synthesis of rat hepatocytes

    International Nuclear Information System (INIS)

    Hirose, Tetsuro; Terajima, Hiroaki; Yamauchi, Akira

    1997-01-01

    Background/Aims: Changes in oxygen availability modulate replicative responses in several cell types, but the effects on hepatocyte replication remain unclear. We have studied the effects of transient nonlethal hypoxia on epidermal growth factor receptor binding and epidermal growth factor-induced DNA synthesis of rat hepatocytes. Methods: Lactate dehydrogenase activity in culture supernatant, intracellular adenosine triphosphate content, 125 I-epidermal growth factor specific binding, epidermal growth factor receptor protein expression, and 3 H-thymidine incorporation were compared between hepatocytes cultured in hypoxia and normoxia. Results: Hypoxia up to 3 h caused no significant increase in lactate dehydrogenase activity in the culture supernatant, while intracellular adenosine triphosphate content decreased time-dependently and was restored to normoxic levels by reoxygenation (nonlethal hypoxia). Concomitantly, 125 I-epidermal growth factor specific binding to hepatocytes decreased time-dependently (to 54.1% of normoxia) and was restored to control levels by reoxygenation, although 125 I-insulin specific binding was not affected. The decrease in 125 I-epidermal growth factor specific binding was explained by the decrease in the number or available epidermal growth factor receptors (21.37±3.08 to 12.16±1.42 fmol/10 5 cells), while the dissociation constant of the receptor was not affected. The change in the number of available receptors was not considered to be due to receptor degradation-resynthesis, since immuno-detection of the epidermal growth factor receptor revealed that the receptor protein expression did not change during hypoxia and reoxygenation, and since neither actinomycin D nor cycloheximide affected the recovery of 125 I-epidermal growth factor binding by reoxygenation. Inhibition of epidermal growth factor-induced DNA synthesis after hypoxia (to 75.4% of normoxia by 3 h hypoxia) paralleled the decrease in 125 I-epidermal growth factor binding

  9. Phosphorylated hepatocyte growth factor receptor/c-Met is associated with tumor growth and prognosis in patients with bladder cancer: correlation with matrix metalloproteinase-2 and -7 and E-cadherin.

    Science.gov (United States)

    Miyata, Yasuyoshi; Sagara, Yuji; Kanda, Shigeru; Hayashi, Tomayoshi; Kanetake, Hiroshi

    2009-04-01

    Hepatocyte growth factor receptor/c-Met is associated with malignant aggressiveness and survival in various cancers including bladder cancer. Although phosphorylation of hepatocyte growth factor receptor/c-Met is essential for its function, the pathologic significance of phosphorylated hepatocyte growth factor receptor/c-Met in bladder cancer remains elusive. We investigated the clinical significance of its expression, and its correlation with cancer cell progression-related molecules. The expression levels of 2 tyrosine residues of hepatocyte growth factor receptor/c-Met (pY1234/1235 and pY1349) were examined immunohistochemically in 133 specimens with nonmetastatic bladder cancer. We also investigated their correlation with matrix metalloproteinase-1, -2, -7, and -14; urokinase-type plasminogen activator; E-cadherin; CD44 standard, variant 3, and variant 6; and vascular endothelial growth factor. Expression of phosphorylated hepatocyte growth factor receptor/c-Met was detected in cancer cells, but was rare in normal urothelial cells. Although hepatocyte growth factor receptor/c-Met, pY1234/1235 hepatocyte growth factor receptor/c-Met, and pY1349 hepatocyte growth factor receptor/c-Met were associated with pT stage, multivariate analysis identified pY1349 hepatocyte growth factor receptor/c-met expression only as a significant factor for high pT stage. Expression of pY1349 hepatocyte growth factor receptor/c-Met was a marker of metastasis and (P = .001) and cause-specific survival (P = .003). Expressions of matrix metalloproteinase-2, matrix metalloproteinase-7, and E-cadherin correlated with pY1349 hepatocyte growth factor receptor/c-Met expression. Our results demonstrated that pY1349 hepatocyte growth factor receptor/c-Met plays an important role in tumor development, and its expression is a significant predictor of metastasis and survival of patients with bladder cancer. The results suggest that these activities are mediated, at least in part, by matrix

  10. Statins, PCSK9 inhibitors and cholesterol homeostasis: a view from within the hepatocyte.

    Science.gov (United States)

    Sniderman, Allan D; Kiss, Robert Scott; Reid, Thomas; Thanassoulis, George; Watts, Gerald F

    2017-05-01

    Statins and PCSK9 inhibitors dramatically lower plasma LDL levels and dramatically increase LDL receptor number within hepatocyte cell membranes. It seems self-evident that total clearance of LDL particles from plasma and total delivery of cholesterol to the liver must increase in consequence. However, based on the results of stable isotope tracer studies, this analysis demonstrates the contrary to be the case. Statins do not change the production rate of LDL particles. Accordingly, at steady state, the clearance rate cannot change. Because LDL particles contain less cholesterol on statin therapy, the delivery of cholesterol to the liver must, therefore, be reduced. PCSK9 inhibitors reduce the production of LDL particles and this further reduces cholesterol delivery to the liver. With both agents, a larger fraction of a smaller pool is removed per unit time. These findings are inconsistent with the conventional model of cholesterol homeostasis within the liver, but are consistent with a new model of regulation, the multi-channel model, which postulates that different lipoprotein particles enter the hepatocyte by different routes and have different metabolic fates within the hepatocyte. The multi-channel model, but not the conventional model, may explain how statins and PCSK9 inhibitors can produce sustained increases in LDL receptor number. © 2017 The Author(s); published by Portland Press Limited on behalf of the Biochemical Society.

  11. Characterisation of citrate and iron citrate uptake by cultured rat hepatocytes

    International Nuclear Information System (INIS)

    Graham, R.M.; Morgan, E.H.; Baker, E.

    1998-01-01

    Background/Aims: the endogenous low molecular weight iron chelator, citrate, is considered to be an important contributor to iron transport and the liver the main site of uptake of iron citrate in subjects suffering from diseases of iron overload. Moreover, the citrate-metabolising enzyme, aconitase, is implicated in the regulation of cellular iron metabolism. This study was undertaken to determine the role of citrate and ferric citrate in the uptake of iron by rat hepatocytes. Methods: Cultured rat hepatocytes were incubated (37 deg. C, 15 min) with 100 μM [ 14 C]-citrate in the presence or absence of 1.0 μM 55 Fe. Membrane-bound and intracellular radiolabel were separated by incubation with the general protease, Pronase. Results: Our results suggest that ferric citrate uptake is mediated by a specific citrate binding site which exhibits a higher affinity for citrate in the presence of iron than in its absence. Citrate was internalised by hepatocytes, with at least 70% being oxidised to CO 2 within 15 min. Citrate uptake was pH-dependent, did not require the presence of sodium and increased with increasing iron concentration. Metabolic energy, anion channels, the Na + , K + -ATPase and vesicle acidification do not appear to play a role in uptake of ferric citrate, but functional sulphydryl groups may be involved. Conclusions: The data suggest either that ferric citrate complexes with higher molar ratios of iron to citrate relative to the incubation medium are bound preferentially to the membrane, or that once citrate has delivered its iron to the membrane, the complex dissociates and the components are internalised separately. (au)

  12. Naked gene therapy of hepatocyte growth factor for dextran sulfate sodium-induced colitis in mice

    International Nuclear Information System (INIS)

    Kanbe, Takamasa; Murai, Rie; Mukoyama, Tomoyuki; Murawaki, Yoshiyuki; Hashiguchi, Ko-ichi; Yoshida, Yoko; Tsuchiya, Hiroyuki; Kurimasa, Akihiro; Harada, Ken-ichi; Yashima, Kazuo; Nishimuki, Eiji; Shabana, Noriko; Kishimoto, Yukihiro; Kojyo, Haruhiko; Miura, Kunihiko; Murawaki, Yoshikazu; Kawasaki, Hironaka; Shiota, Goshi

    2006-01-01

    Ulcerative colitis (UC) is progressive and relapsing disease. To explore the therapeutic effects of naked gene therapy of hepatocyte growth factor (HGF) on UC, the SRα promoter driving HGF gene was intrarectally administered to the mice in which colitis was induced by dextran sulfate sodium (DSS). Expression of the transgene was seen in surface epithelium, lamina propria, and muscularis mucosae. The HGF-treated mice showed reduced colonic mucosal damage and increased body weights, compared with control mice (P < 0.01 and P < 0.05, respectively). The HGF-treated mice displayed increased number of PCNA-positive cells and decreased number of apoptotic cells than in control mice (P < 0.01, each). Phosphorylated AKT was dramatically increased after HGF gene administration, however, phosphorylated ERK1/2 was not altered. Microarray analysis revealed that HGF induced expression of proliferation- and apoptosis-associated genes. These data suggest that naked HGF gene delivery causes therapeutic effects through regulation of many downstream genes

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

    Directory of Open Access Journals (Sweden)

    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.

  14. Glutamic Acid - Amino Acid, Neurotransmitter, and Drug - Is Responsible for Protein Synthesis Rhythm in Hepatocyte Populations in vitro and in vivo.

    Science.gov (United States)

    Brodsky, V Y; Malchenko, L A; Konchenko, D S; Zvezdina, N D; Dubovaya, T K

    2016-08-01

    Primary cultures of rat hepatocytes were studied in serum-free media. Ultradian protein synthesis rhythm was used as a marker of cell synchronization in the population. Addition of glutamic acid (0.2 mg/ml) to the medium of nonsynchronous sparse cultures resulted in detection of a common protein synthesis rhythm, hence in synchronization of the cells. The antagonist of glutamic acid metabotropic receptors MCPG (0.01 mg/ml) added together with glutamic acid abolished the synchronization effect; in sparse cultures, no rhythm was detected. Feeding rats with glutamic acid (30 mg with food) resulted in protein synthesis rhythm in sparse cultures obtained from the rats. After feeding without glutamic acid, linear kinetics of protein synthesis was revealed. Thus, glutamic acid, a component of blood as a non-neural transmitter, can synchronize the activity of hepatocytes and can form common rhythm of protein synthesis in vitro and in vivo. This effect is realized via receptors. Mechanisms of cell-cell communication are discussed on analyzing effects of non-neural functions of neurotransmitters. Glutamic acid is used clinically in humans. Hence, a previously unknown function of this drug is revealed.

  15. Quercetin Isolated from Toona sinensis Leaves Attenuates Hyperglycemia and Protects Hepatocytes in High-Carbohydrate/High-Fat Diet and Alloxan Induced Experimental Diabetic Mice

    Directory of Open Access Journals (Sweden)

    Yali Zhang

    2016-01-01

    Full Text Available The development of diabetes mellitus is related to oxidant stress induced by a high carbohydrate/high-fat diet (HFD. Quercetin, as a major bioactive component in Toona sinensis leaves (QTL, is a natural antioxidant. However, the exact mechanism by which QTL ameliorate diabetes mellitus is still unknown. In this study, we investigated the hypoglycemic effects and hepatocytes protection of QTL on HFD and alloxan induced diabetic mice. Intragastric administration of QTL significantly reduced body weight gain, serum glucose, insulin, total cholesterol, triglyceride, low density lipoprotein-cholesterol, alanine aminotransferase, and aspartate aminotransferase serum levels compared to those of diabetic mice. Furthermore, it significantly attenuated oxidative stress, as determined by lipid peroxidation, nitric oxide content, and inducible nitric oxide synthase activity and as a result attenuated liver injury. QTL also significantly suppressed the diabetes-induced activation of the p65/NF-κB and ERK1/2/MAPK pathways, as well as caspase-9 and caspase-3 levels in liver tissues of diabetic mice. Finally, micrograph analysis of liver samples showed decreased cellular organelle injury in hepatocytes of QTL treated mice. Taken together, QTL can be viewed as a promising dietary agent that can be used to reduce the risk of diabetes mellitus and its secondary complications by ameliorating oxidative stress in the liver.

  16. Exosome RNA Released by Hepatocytes Regulates Innate Immune Responses to Hepatitis B Virus Infection

    Directory of Open Access Journals (Sweden)

    Takahisa Kouwaki

    2016-08-01

    Full Text Available The innate immune system is essential for controlling viral infection. Hepatitis B virus (HBV persistently infects human hepatocytes and causes hepatocellular carcinoma. However, the innate immune response to HBV infection in vivo remains unclear. Using a tree shrew animal model, we showed that HBV infection induced hepatic interferon (IFN-γ expression during early infection. Our in vitro study demonstrated that hepatic NK cells produced IFN-γ in response to HBV only in the presence of hepatic F4/80+ cells. Moreover, extracellular vesicles released from HBV-infected hepatocytes contained viral nucleic acids and induced NKG2D ligand expression in macrophages by stimulating MyD88, TICAM-1, and MAVS-dependent pathways. In addition, depletion of exosomes from extracellular vesicles markedly reduced NKG2D ligand expression, suggesting the importance of exosomes for NK cell activation. In contrast, infection of hepatocytes with HBV increased immunoregulatory microRNA levels in extracellular vesicles and exosomes, which were transferred to macrophages, thereby suppressing IL-12p35 mRNA expression in macrophages to counteract the host innate immune response. IFN-γ increased the hepatic expression of DDX60 and augmented the DDX60-dependent degradation of cytoplasmic HBV RNA. Our results elucidated the crucial role of exosomes in antiviral innate immune response against HBV.

  17. In vitro evaluation of encapsulated primary rat hepatocytes pre- and post-cryopreservation at -80°C and in liquid nitrogen.

    Science.gov (United States)

    Durkut, Serap; Elçin, A Eser; Elçin, Y Murat

    2015-02-01

    Encapsulation techniques have the potential to protect hepatocytes from cryoinjury. In this study, we comparatively evaluated the viability and metabolic function of primary rat hepatocytes encapsulated in calcium alginate microbeads, in chitosan tripolyphosphate beads, and in three-layered alginate-chitosan-alginate (ACA) microcapsules, before and after cryopreservation at -80°C and in liquid nitrogen (LN2) for 1 and 3 months. Findings demonstrated that LN2 was atop of -80°C in regard to preservation of viability (> 90%) and hepatic functions. LN2-cryopreserved hepatocytes encapsulated in ACA microcapsules retained metabolic function post-thawing, with > 90% of the albumin, total protein and urea syntheses activities, and > 80% of oxidative function.

  18. Secretion of 35SO4-labeled proteins from isolated rat hepatocytes

    International Nuclear Information System (INIS)

    von Wuertemberg, M.M.F.; Fries, E.

    1989-01-01

    Sulfation is a Golgi-specific modification of secretory proteins. We have characterized the proteins that are labeled with 35 SO 4 in cultures of rat hepatocytes and studied their transport to the medium. Analysis by polyacrylamide gel electrophoresis showed that of the five most heavily labeled proteins, four had well-defined mobilities--apparent molecular masses of 188, 142, 125, and 82 kDa--whereas one was electrophoretically heterogeneous--apparent molecular mass of 35-45 kDa. Judging by their relatively high resistance to acid treatment, the sulfate residues in the 125- and 35-45-kDa proteins were linked to carbohydrate. Some of the secreted proteins were sialylated. In samples of pulse-labeled cells, there appeared to be no unsialylated forms, indicating that sulfation occurred after sialylation, presumably in the trans Golgi. Kinetic experiments showed that the cellular half-life was the same for all the sulfated proteins--about 8 min--consistent with the idea that transport from the Golgi complex to the cell surface occurs by liquid bulk flow

  19. Asialoglycoprotein-receptor-targeted hepatocyte imaging using {sup 99m}Tc galactosylated chitosan

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun-Mi [Department of Nuclear Medicine, Research Institute of Clinical Medicine, Chonbuk National University School of Medicine, Jeonju, Jeonbuk (Korea, Republic of); Jeong, Hwan-Jeong [Department of Nuclear Medicine, Research Institute of Clinical Medicine, Chonbuk National University School of Medicine, Jeonju, Jeonbuk (Korea, Republic of)]. E-mail: jayjeong@chonbuk.ac.kr; Kim, Se-Lim [Department of Nuclear Medicine, Research Institute of Clinical Medicine, Chonbuk National University School of Medicine, Jeonju, Jeonbuk (Korea, Republic of); Sohn, Myung-Hee [Department of Nuclear Medicine, Research Institute of Clinical Medicine, Chonbuk National University School of Medicine, Jeonju, Jeonbuk (Korea, Republic of); Nah, Jae-Woon [Division of Applied Materials Engineering, Department of Polymer Science and Engineering, Sunchon National University, Sunchon, Jeonnam (Korea, Republic of); Bom, Hee-Seung [Department of Nuclear Medicine, Chonnam National University School of Medicine, Gwangju (Korea, Republic of); Park, In-Kyu [School of Agricultural Biotechnology, Seoul National University, Seoul (Korea, Republic of); Cho, Chong-Su [School of Agricultural Biotechnology, Seoul National University, Seoul (Korea, Republic of)

    2006-05-15

    This study investigated the usefulness of {sup 99m}Tc hydrazinonicotinamide-galactosylated chitosan (HGC) in hepatocyte imaging. HGC was obtained by coupling the galactose moiety of both lactobionic acid and succinimidyl 6-hydrazinonicotinate hydrochloride (succinimidyl HYNIC). The coupled product was then radiolabeled with {sup 99m}Tc using stannous chloride and tricine as reducing agent and coligand, respectively. Labeling efficiency was >90% both in room temperature and in serum up to 24 h after injection. The hepatic uptake properties of {sup 99m}Tc HGC were studied in Balb/C mice. {sup 99m}Tc HGC and {sup 99m}Tc hydrazinonicotinamide chitosan (HC) were intravenously injected into mice, with receptor binding identified by coinjection with 9 and 14 mg of free galactose. Images were acquired with a {gamma}-camera. After injection via the tail vein of the mice, {sup 99m}Tc HGC showed high selectivity for the liver, while {sup 99m}Tc HC without a galactose group showed low liver uptake. In addition, the hepatic uptake of {sup 99m}Tc HGC was blocked by coinjection of free galactose. Tissue distribution was determined at three different times (10, 60 and 120 min). The liver accumulated 13.16{+-}2.72%, 16.11{+-}5.70% and 16.55{+-}2.28% of the injected dose per gram at 10, 60 and 120 min after injection, respectively. {sup 99m}Tc HGC showed specific and rapid targeting of hepatocytes. It is a promising receptor-specific radiopharmaceutical with potential applications in liver imaging for the evaluation of hepatocytic function.

  20. Silk sericin-alginate-chitosan microcapsules: hepatocytes encapsulation for enhanced cellular functions.

    Science.gov (United States)

    Nayak, Sunita; Dey, Sanchareeka; Kundu, Subhas C

    2014-04-01

    The encapsulation based technology permits long-term delivery of desired therapeutic products in local regions of body without the need of immunosuppressant drugs. In this study microcapsules composed of sericin and alginate micro bead as inner core and with an outer chitosan shell are prepared. This work is proposed for live cell encapsulation for potential therapeutic applications. The sericin protein is obtained from cocoons of non-mulberry silkworm Antheraea mylitta. The sericin-alginate micro beads are prepared via ionotropic gelation under high applied voltage. The beads further coated with chitosan and crosslinked with genipin. The microcapsules developed are nearly spherical in shape with smooth surface morphology. Alamar blue assay and confocal microscopy indicate high cell viability and uniform encapsulated cell distribution within the sericin-alginate-chitosan microcapsules indicating that the microcapsules maintain favourable microenvironment for the cells. The functional analysis of encapsulated cells demonstrates that the glucose consumption, urea secretion rate and intracellular albumin content increased in the microcapsules. The study suggests that the developed sericin-alginate-chitosan microcapsule contributes towards the development of cell encapsulation model. It also offers to generate enriched population of metabolically and functionally active cells for the future therapeutics especially for hepatocytes transplantation in acute liver failure. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. EFFECT OF ETHANOL ON HEPATOBILIARY TRANSPORT OF CATIONIC DRUGS - A STUDY IN THE ISOLATED-PERFUSED RAT-LIVER, RAT HEPATOCYTES AND RAT MITOCHONDRIA

    NARCIS (Netherlands)

    STEEN, H; MEIJER, DKF; Merema, M.T.

    The effect of ethanol on the hepatic uptake of various cationic drugs was studied in isolated perfused rat livers, isolated rat hepatocytes and isolated rat liver mitochondria. In isolated rat hepatocytes and in isolated perfused rat livers, the uptake of the model organic cation

  2. Effects of insulin-like growth factor-1 on the assembly and secretion of very low-density lipoproteins in cow hepatocytes in vitro.

    Science.gov (United States)

    Li, Xinwei; Guan, Yuan; Li, Ying; Wu, Dianjun; Liu, Lei; Deng, Qinghua; Li, Xiaobing; Wang, Zhe; Liu, Guowen

    2016-01-15

    Fatty liver is a major metabolic disorder of dairy cows. One important reason is that hepatic very low-density lipoproteins (VLDL) assembly was significant decreased in dairy cows with fatty liver. In addition, the impairment of insulin-like growth factor (IGF)-1 synthesis was involved in the development of fatty liver. Therefore, the objective of this study was to investigate the effects of IGF-1 on the VLDL assembly in cow hepatocytes. In this study, cow hepatocytes were cultured and then transfected with Ad-GFP-IGF-1 (inhibited the IGF-1 expression) and Ad-GFP (negative control), and treated with different concentrations of IGF-1, respectively. The results showed that IGF-1 increased the mRNA abundance of apolipoprotein B100 (ApoB100), apolipoprotein E (ApoE), microsomal triglyceride transfer protein (MTTP), and low-density lipoprotein receptor (LDLR) and then increased the VLDL assembly in cow hepatocytes. Nevertheless, impairment of IGF-1 expression by Ad-GFP-IGF-1 could inhibit above genes expression and VLDL assembly in hepatocytes. Taken together, these results indicate that IGF-1 increases the VLDL assembly and impairment of IGF-1 expression decreases the VLDL assembly in cow hepatocytes. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Effects of Kisspeptin-10 on Lipid Metabolism in Cultured Chicken Hepatocytes

    Directory of Open Access Journals (Sweden)

    J. Wu

    2012-09-01

    Full Text Available Our previous studies showed that kisspeptin-10 (Kp-10 injected in vivo can markedly increase lipid anabolism in liver of quails. In order to investigate the direct effect of Kp-10 on lipid metabolism of hepatocytes in birds, cells were separated from embryos livers and cultured in vitro with 0, 100 and 1,000 nM Kp-10, respectively. The results showed that after 24 h treatment, cells viability was not affected by 100 nM Kp-10, but showed a mild decrease with 1,000 nM Kp-10 compared to the control cells. Based on the results of the cell viability, 100 nM dosage of Kp-10 was selected for the further study and analysis. Compared with control cells, total cholesterol (Tch contents in 100 nM treated cells were increased by 51.23%, but did not reach statistical significance, while the level of triglyceride (TG, high density of lipoprotein-cholesterol (HDL-C and low density of lipoprotein-cholesterol (LDL-C were significantly increased. Real-time PCR results showed that ApoVLDL-II mRNA expression had a tendency to increase, genes including sterol regulatory element-binding protein-1 (SREBP-1, acetyl coenzyme A carboxylase α (ACCα, carnitine palmitoyltransferase 1 (CPT1, 3-hydroxyl-3-methylglutaryl-coenzyme A reductases (HMGCR and stearyl coenzyme A dehydrogenase-1 (SCD1 mRNA in hepatocytes were significantly down-regulated by 100 nM Kp-10. However, contrary to its gene expression, SREBP-1 protein expression was significantly up-regulated by 100 nM Kp-10. Some of the significant correlations in mRNA expression were found between genes encoding hepatic factors or enzymes involved in lipid metabolism in liver of birds. These results indicate that Kp-10 stimulates lipid synthesis directly in primary cultured hepatocytes of chickens.

  4. Antioxidant and cytoprotective properties of D-tagatose in cultured murine hepatocytes.

    Science.gov (United States)

    Paterna, J C; Boess, F; Stäubli, A; Boelsterli, U A

    1998-01-01

    D-Tagatose is a zero-energy producing ketohexose that is a powerful cytoprotective agent against chemically induced cell injury. To further explore the underlying mechanisms of cytoprotection, we investigated the effects of D-tagatose on both the generation of superoxide anion radicals and the consequences of oxidative stress driven by prooxidant compounds in intact cells. Primary cultures of hepatocytes derived from male C57BL/6 mice were exposed to the redox cycling drug nitrofurantoin (NFT). Lethal cell injury induced by 300 microM NFT was completely prevented by high concentrations (20 mM) of D-tagatose, whereas equimolar concentrations of glucose, mannitol, or xylose were ineffective. The extent of NFT-induced intracellular superoxide anion radical formation was not altered by D-tagatose, indicating that the ketohexose did not inhibit the reductive bioactivation of NFT. However, the NFT-induced decline of the intracellular GSH content was largely prevented by D-tagatose. The sugar also afforded complete protection against NFT toxicity in hepatocytes that had been chemically depleted of GSH. Furthermore, the ketohexose fully protected from increases in both membrane lipid peroxidation and protein carbonyl formation. In addition, D-tagatose completely prevented oxidative cell injury inflicted by toxic iron overload with ferric nitrilotriacetate (100 microM). In contrast, D-tagatose did not protect against lethal cell injury induced by tert-butyl hydroperoxide, a prooxidant which acts by hydroxyl radical-independent mechanisms and which is partitioned in the lipid bilayer. These results indicate that D-tagatose, which is a weak iron chelator, can antagonize the iron-dependent toxic consequences of intracellular oxidative stress in hepatocytes. The antioxidant properties of D-tagatose may result from sequestering the redox-active iron, thereby protecting more critical targets from the damaging potential of hydroxyl radical.

  5. A biomimetic porous hydrogel of gelatin and glycosaminoglycans cross-linked with transglutaminase and its application in the culture of hepatocytes

    International Nuclear Information System (INIS)

    De Colli, M; Massimi, M; Barbetta, A; Di Rosario, B L; Nardecchia, S; Dentini, M; Conti Devirgiliis, L

    2012-01-01

    The development of blended gelatin and glycosaminoglycan (GAG) scaffolds can potentially be used in many soft tissue engineering applications since these scaffolds mimic the structure and biological function of native extracellular matrix (ECM). In this study, we were able to obtain a gelatin–GAG scaffold by using a concentrated emulsion templating technique known as high internal phase emulsion (HIPE), in which a prevailing in volume organic phase is dispersed in the form of discrete droplets inside an aqueous solution of three biopolymers represented by gelatin, hyaluronic acid (HA) and chondroitin sulfate (CS) in the presence of a suitable surfactant. In order to preserve the bioactive potential of the biopolymers employed, the cross-linking procedure involved the use of transglutaminase (MTGase) that catalyzes the formation of covalent N-ε-(γ-glutamyl) lysine amide bonds. Since neither HA nor CS possess the necessary primary amino groups toward which MTGase is active, they were functionalized with the dipeptide glycine-lysine (GK). In this way the introduction of foreign cross-linking bridging units with an unpredictable biocompatibility was avoided. These enzymatic cross-linked gelatin–GAG scaffolds were tested in the culture of primary rat and C3A hepatocytes. Results underlined the good performance of this novel support in maintaining and promoting hepatocyte functions in vitro. (paper)

  6. Insulin suppresses the AMPK signaling pathway to regulate lipid metabolism in primary cultured hepatocytes of dairy cows.

    Science.gov (United States)

    Li, Xinwei; Li, Yu; Ding, Hongyan; Dong, Jihong; Zhang, Renhe; Huang, Dan; Lei, Lin; Wang, Zhe; Liu, Guowen; Li, Xiaobing

    2018-05-01

    Dairy cows with type II ketosis display hepatic fat accumulation and hyperinsulinemia, but the underlying mechanism is not completely clear. This study aimed to clarify the regulation of lipid metabolism by insulin in cow hepatocytes. In vitro, cow hepatocytes were treated with 0, 1, 10, or 100 nm insulin in the presence or absence of AICAR (an AMP-activated protein kinase alpha (AMPKα) activator). The results showed that insulin decreased AMPKα phosphorylation. This inactivation of AMPKα increased the gene and protein expression levels of carbohydrate responsive element-binding protein (ChREBP) and sterol regulatory element-binding protein-1c (SREBP-1c), which downregulated the expression of lipogenic genes, thereby decreasing lipid biosynthesis. Furthermore, AMPKα inactivation decreased the gene and protein expression levels of peroxisome proliferator-activated receptor-α (PPARα), which upregulated the expression of lipid oxidation genes, thereby increasing lipid oxidation. In addition, insulin decreased the very low density lipoprotein (VLDL) assembly. Consequently, triglyceride content was significantly increased in insulin treated hepatocytes. Activation of AMPKα induced by AICAR could reverse the effect of insulin on PPARα, SREBP-1c, and ChREBP, thereby decreasing triglyceride content. These results indicate that insulin inhibits the AMPKα signaling pathway to increase lipid synthesis and decrease lipid oxidation and VLDL assembly in cow hepatocytes, thereby inducing TG accumulation. This mechanism could partly explain the causal relationship between hepatic fat accumulation and hyperinsulinemia in dairy cows with type II ketosis.

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

    International Nuclear Information System (INIS)

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

    2013-01-01

    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. - 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

  8. Bolstering cholesteryl ester hydrolysis in liver: A hepatocyte-targeting gene delivery strategy for potential alleviation of atherosclerosis.

    Science.gov (United States)

    He, Hongliang; Lancina, Michael G; Wang, Jing; Korzun, William J; Yang, Hu; Ghosh, Shobha

    2017-06-01

    Current atherosclerosis treatment strategies primarily focus on limiting further cholesteryl esters (CE) accumulation by reducing endogenous synthesis of cholesterol in the liver. No therapy is currently available to enhance the removal of CE, a crucial step to reduce the burden of the existing disease. Given the central role of hepatic cholesteryl ester hydrolase (CEH) in the intrahepatic hydrolysis of CE and subsequent removal of the resulting free cholesterol (FC), in this work, we applied galactose-functionalized polyamidoamine (PAMAM) dendrimer generation 5 (Gal-G5) for hepatocyte-specific delivery of CEH expression vector. The data presented herein show the increased specific uptake of Gal-G5/CEH expression vector complexes (simply Gal-G5/CEH) by hepatocytes in vitro and in vivo. Furthermore, the upregulated CEH expression in the hepatocytes significantly enhanced the intracellular hydrolysis of high density lipoprotein-associated CE (HDL-CE) and subsequent conversion/secretion of hydrolyzed FC as bile acids (BA). The increased CEH expression in the liver significantly increased the flux of HDL-CE to biliary as well as fecal FC and BA. Meanwhile, Gal-G5 did not induce hepatic or renal toxicity. It was also not immunotoxic. Because of these encouraging pre-clinical testing results, using this safe and highly efficient hepatocyte-specific gene delivery platform to enhance the hepatic processes involved in cholesterol elimination is a promising strategy for the alleviation of atherosclerosis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. 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.

  10. Mechanisms of acetaminophen-induced cell death in primary human hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Yuchao; McGill, Mitchell R.; Dorko, Kenneth [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160 (United States); Kumer, Sean C.; Schmitt, Timothy M.; Forster, Jameson [Department of Surgery, University of Kansas Medical Center, Kansas City, KS 66160 (United States); Jaeschke, Hartmut, E-mail: hjaeschke@kumc.edu [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160 (United States)

    2014-09-15

    Acetaminophen (APAP) overdose is the most prevalent cause of drug-induced liver injury in western countries. Numerous studies have been conducted to investigate the mechanisms of injury after APAP overdose in various animal models; however, the importance of these mechanisms for humans remains unclear. Here we investigated APAP hepatotoxicity using freshly isolated primary human hepatocytes (PHH) from either donor livers or liver resections. PHH were exposed to 5 mM, 10 mM or 20 mM APAP over a period of 48 h and multiple parameters were assessed. APAP dose-dependently induced significant hepatocyte necrosis starting from 24 h, which correlated with the clinical onset of human liver injury after APAP overdose. Interestingly, cellular glutathione was depleted rapidly during the first 3 h. APAP also resulted in early formation of APAP-protein adducts (measured in whole cell lysate and in mitochondria) and mitochondrial dysfunction, indicated by the loss of mitochondrial membrane potential after 12 h. Furthermore, APAP time-dependently triggered c-Jun N-terminal kinase (JNK) activation in the cytosol and translocation of phospho-JNK to the mitochondria. Both co-treatment and post-treatment (3 h) with the JNK inhibitor SP600125 reduced JNK activation and significantly attenuated cell death at 24 h and 48 h after APAP. The clinical antidote N-acetylcysteine offered almost complete protection even if administered 6 h after APAP and a partial protection when given at 15 h. Conclusion: These data highlight important mechanistic events in APAP toxicity in PHH and indicate a critical role of JNK in the progression of injury after APAP in humans. The JNK pathway may represent a therapeutic target in the clinic. - Highlights: • APAP reproducibly causes cell death in freshly isolated primary human hepatocytes. • APAP induces adduct formation, JNK activation and mitochondrial dysfunction in PHH. • Mitochondrial adducts and JNK translocation are delayed in PHH compared to

  11. Small-Molecule-Directed Hepatocyte-Like Cell Differentiation of Human Pluripotent Stem Cells.

    Science.gov (United States)

    Mathapati, Santosh; Siller, Richard; Impellizzeri, Agata A R; Lycke, Max; Vegheim, Karianne; Almaas, Runar; Sullivan, Gareth J

    2016-08-17

    Hepatocyte-like cells (HLCs) generated in vitro from human pluripotent stem cells (hPSCs) provide an invaluable resource for basic research, regenerative medicine, drug screening, toxicology, and modeling of liver disease and development. This unit describes a small-molecule-driven protocol for in vitro differentiation of hPSCs into HLCs without the use of growth factors. hPSCs are coaxed through a developmentally relevant route via the primitive streak to definitive endoderm (DE) using the small molecule CHIR99021 (a Wnt agonist), replacing the conventional growth factors Wnt3A and activin A. The small-molecule-derived DE is then differentiated to hepatoblast-like cells in the presence of dimethyl sulfoxide. The resulting hepatoblasts are then differentiated to HLCs with N-hexanoic-Tyr, Ile-6 aminohexanoic amide (Dihexa, a hepatocyte growth factor agonist) and dexamethasone. The protocol provides an efficient and reproducible procedure for differentiation of hPSCs into HLCs utilizing small molecules. © 2016 by John Wiley & Sons, Inc. Copyright © 2016 John Wiley & Sons, Inc.

  12. Stem Cells from Cryopreserved Human Dental Pulp Tissues Sequentially Differentiate into Definitive Endoderm and Hepatocyte-Like Cells in vitro.

    Science.gov (United States)

    Han, Young-Jin; Kang, Young-Hoon; Shivakumar, Sarath Belame; Bharti, Dinesh; Son, Young-Bum; Choi, Yong-Ho; Park, Won-Uk; Byun, June-Ho; Rho, Gyu-Jin; Park, Bong-Wook

    2017-01-01

    We previously described a novel tissue cryopreservation protocol to enable the safe preservation of various autologous stem cell sources. The present study characterized the stem cells derived from long-term cryopreserved dental pulp tissues (hDPSCs-cryo) and analyzed their differentiation into definitive endoderm (DE) and hepatocyte-like cells (HLCs) in vitro . Human dental pulp tissues from extracted wisdom teeth were cryopreserved as per a slow freezing tissue cryopreservation protocol for at least a year. Characteristics of hDPSCs-cryo were compared to those of stem cells from fresh dental pulps (hDPSCs-fresh). hDPSCs-cryo were differentiated into DE cells in vitro with Activin A as per the Wnt3a protocol for 6 days. These cells were further differentiated into HLCs in the presence of growth factors until day 30. hDPSCs-fresh and hDPSCs-cryo displayed similar cell growth morphology, cell proliferation rates, and mesenchymal stem cell character. During differentiation into DE and HLCs in vitro , the cells flattened and became polygonal in shape, and finally adopted a hepatocyte-like shape. The differentiated DE cells at day 6 and HLCs at day 30 displayed significantly increased DE- and hepatocyte-specific markers at the mRNA and protein level, respectively. In addition, the differentiated HLCs showed detoxification and glycogen storage capacities, indicating they could share multiple functions with real hepatocytes. These data conclusively show that hPDSCs-cryo derived from long-term cryopreserved dental pulp tissues can be successfully differentiated into DE and functional hepatocytes in vitro . Thus, preservation of dental tissues could provide a valuable source of autologous stem cells for tissue engineering.

  13. Augmentation of DHCR24 expression by hepatitis C virus infection facilitates viral replication in hepatocytes.

    Science.gov (United States)

    Takano, Takashi; Tsukiyama-Kohara, Kyoko; Hayashi, Masahiro; Hirata, Yuichi; Satoh, Masaaki; Tokunaga, Yuko; Tateno, Chise; Hayashi, Yukiko; Hishima, Tsunekazu; Funata, Nobuaki; Sudoh, Masayuki; Kohara, Michinori

    2011-09-01

    We characterized the role of 24-dehydrocholesterol reductase (DHCR24) in hepatitis C virus infection (HCV). DHCR24 is a cholesterol biosynthetic enzyme and cholesterol is a major component of lipid rafts, which is reported to play an important role in HCV replication. Therefore, we examined the potential of DHCR24 as a target for novel HCV therapeutic agents. We examined DHCR24 expression in human hepatocytes in both the livers of HCV-infected patients and those of chimeric mice with human hepatocytes. We targeted DHCR24 with siRNA and U18666A which is an inhibitor of both DHCR24 and cholesterol synthesis. We measured the level of HCV replication in these HCV replicon cell lines and HCV infected cells. U18666A was administrated into chimeric mice with humanized liver, and anti-viral effects were assessed. Expression of DHCR24 was induced by HCV infection in human hepatocytes in vitro, and in human hepatocytes of chimeric mouse liver. Silencing of DHCR24 by siRNA decreased HCV replication in replicon cell lines and HCV JFH-1 strain-infected cells. Treatment with U18666A suppressed HCV replication in the replicon cell lines. Moreover, to evaluate the anti-viral effect of U18666A in vivo, we administrated U18666A with or without pegylated interferon to chimeric mice and observed an inhibitory effect of U18666A on HCV infection and a synergistic effect with interferon. DHCR24 is an essential host factor which augmented its expression by HCV infection, and plays a significant role in HCV replication. DHCR24 may serve as a novel anti-HCV drug target. Copyright © 2010 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

  14. Gadoxetate-enhanced MR imaging and compartmental modelling to assess hepatocyte bidirectional transport function in rats with advanced liver fibrosis

    Energy Technology Data Exchange (ETDEWEB)

    Giraudeau, Celine; Leporq, Benjamin; Doblas, Sabrina [University Paris Diderot, Sorbonne Paris Cite, Hopital Beaujon, Laboratory of Imaging Biomarkers, UMR1149 Inserm, Clichy (France); Lagadec, Matthieu; Daire, Jean-Luc; Van Beers, Bernard E. [University Paris Diderot, Sorbonne Paris Cite, Hopital Beaujon, Laboratory of Imaging Biomarkers, UMR1149 Inserm, Clichy (France); Beaujon University Hospital Paris Nord, Department of Radiology, Clichy (France); Pastor, Catherine M. [University Paris Diderot, Sorbonne Paris Cite, Hopital Beaujon, Laboratory of Imaging Biomarkers, UMR1149 Inserm, Clichy (France); Hopitaux Universitaires de Geneve, Departement d' Imagerie et des Sciences de l' Information Medicale, Geneva (Switzerland)

    2017-05-15

    Changes in the expression of hepatocyte membrane transporters in advanced fibrosis decrease the hepatic transport function of organic anions. The aim of our study was to assess if these changes can be evaluated with pharmacokinetic analysis of the hepatobiliary transport of the MR contrast agent gadoxetate. Dynamic gadoxetate-enhanced MRI was performed in 17 rats with advanced fibrosis and 8 normal rats. After deconvolution, hepatocyte three-compartmental analysis was performed to calculate the hepatocyte influx, biliary efflux and sinusoidal backflux rates. The expression of Oatp1a1, Mrp2 and Mrp3 organic anion membrane transporters was assessed with reverse transcription polymerase chain reaction. In the rats with advanced fibrosis, the influx and efflux rates of gadoxetate decreased and the backflux rate increased significantly (p = 0.003, 0.041 and 0.010, respectively). Significant correlations were found between influx and Oatp1a1 expression (r = 0.78, p < 0.001), biliary efflux and Mrp2 (r = 0.50, p = 0.016) and sinusoidal backflux and Mrp3 (r = 0.61, p = 0.002). These results show that changes in the bidirectional organic anion hepatocyte transport function in rats with advanced liver fibrosis can be assessed with compartmental analysis of gadoxetate-enhanced MRI. (orig.)

  15. Gadoxetate-enhanced MR imaging and compartmental modelling to assess hepatocyte bidirectional transport function in rats with advanced liver fibrosis

    International Nuclear Information System (INIS)

    Giraudeau, Celine; Leporq, Benjamin; Doblas, Sabrina; Lagadec, Matthieu; Daire, Jean-Luc; Van Beers, Bernard E.; Pastor, Catherine M.

    2017-01-01

    Changes in the expression of hepatocyte membrane transporters in advanced fibrosis decrease the hepatic transport function of organic anions. The aim of our study was to assess if these changes can be evaluated with pharmacokinetic analysis of the hepatobiliary transport of the MR contrast agent gadoxetate. Dynamic gadoxetate-enhanced MRI was performed in 17 rats with advanced fibrosis and 8 normal rats. After deconvolution, hepatocyte three-compartmental analysis was performed to calculate the hepatocyte influx, biliary efflux and sinusoidal backflux rates. The expression of Oatp1a1, Mrp2 and Mrp3 organic anion membrane transporters was assessed with reverse transcription polymerase chain reaction. In the rats with advanced fibrosis, the influx and efflux rates of gadoxetate decreased and the backflux rate increased significantly (p = 0.003, 0.041 and 0.010, respectively). Significant correlations were found between influx and Oatp1a1 expression (r = 0.78, p < 0.001), biliary efflux and Mrp2 (r = 0.50, p = 0.016) and sinusoidal backflux and Mrp3 (r = 0.61, p = 0.002). These results show that changes in the bidirectional organic anion hepatocyte transport function in rats with advanced liver fibrosis can be assessed with compartmental analysis of gadoxetate-enhanced MRI. (orig.)

  16. Foxa1 reduces lipid accumulation in human hepatocytes and is down-regulated in nonalcoholic fatty liver.

    Directory of Open Access Journals (Sweden)

    Marta Moya

    Full Text Available Triglyceride accumulation in nonalcoholic fatty liver (NAFL results from unbalanced lipid metabolism which, in the liver, is controlled by several transcription factors. The Foxa subfamily of winged helix/forkhead box (Fox transcription factors comprises three members which play important roles in controlling both metabolism and homeostasis through the regulation of multiple target genes in the liver, pancreas and adipose tissue. In the mouse liver, Foxa2 is repressed by insulin and mediates fasting responses. Unlike Foxa2 however, the role of Foxa1 in the liver has not yet been investigated in detail. In this study, we evaluate the role of Foxa1 in two human liver cell models, primary cultured hepatocytes and HepG2 cells, by adenoviral infection. Moreover, human and rat livers were analyzed to determine Foxa1 regulation in NAFL. Results demonstrate that Foxa1 is a potent inhibitor of hepatic triglyceride synthesis, accumulation and secretion by repressing the expression of multiple target genes of these pathways (e.g., GPAM, DGAT2, MTP, APOB. Moreover, Foxa1 represses the fatty acid transporter protein FATP2 and lowers fatty acid uptake. Foxa1 also increases the breakdown of fatty acids by inducing peroxisomal fatty acid β-oxidation and ketone body synthesis. Finally, Foxa1 is able to largely up-regulate UCP1, thereby dissipating energy and consistently decreasing the mitochondria membrane potential. We also report that human and rat NAFL have a reduced Foxa1 expression, possibly through a protein kinase C-dependent pathway. We conclude that Foxa1 is an antisteatotic factor that coordinately tunes several lipid metabolic pathways to block triglyceride accumulation in hepatocytes. However, Foxa1 is down-regulated in human and rat NAFL and, therefore, increasing Foxa1 levels could protect from steatosis. Altogether, we suggest that Foxa1 could be a novel therapeutic target for NAFL disease and insulin resistance.

  17. Protective role of Urtica dioica L. (Urticaceae) extract on hepatocytes morphometric changes in STZ diabetic Wistar rats.

    Science.gov (United States)

    Golalipour, Mohammad Jafar; Ghafari, Soraya; Afshar, Mohammad

    2010-09-01

    The present investigation was carried out to evaluate the protective effect of the hydroalcoholic extract of Urtica dioica leaves on the quantitative morphometric changes in the liver of streptozotocin-induced diabetic rats. Thirty male Wistar rats were divided into control (G1), diabetic (G2), diabetic + Urtica dioica (G3) groups. The control group received only sham injections of intraperitoneal saline; the diabetic group received intraperitoneal saline for 5 days followed by streptozotocin (80 mg/kg) on the 6th day; and the diabetic + Urtica dioica group received 100 mg/kg Urtica dioica intraperitoneal (7) injections for 5 days and streptozotocin injection on the 6th day. After five weeks, the animals were sacrificed and whole livers removed. Liver specimens were used for quantitative morphometric analysis after hematoxylin and eosin staining. All data were statistically analyzed by one-way ANOVA and expressed as the mean with standard error of means. In the G3 (diabetic + Urtica diocia) group, the mean surface area of hepatocytes in the periportal zone (Z1) was greater than in G2 (diabetic) and G1 (control) groups, but this difference was not significant. No alteration was observed in the surface area of hepatocytes in the perivenous zone (Z3) in the diabetic + Urtica dioica (G3) group compared to the diabetic (G2) group. The mean nuclear area of hepatocytes of the rats in the diabetic + Urtica dioica (G3) group was higher in Z1 and lower in Z3 than that of rats in the diabetic (G2) group. The mean diameter of hepatocyte nuclei in the diabetic + Urtica dioica (G3) group was lower than that of diabetic (G2) and control (G1) groups in both Z1 and Z3. This study revealed that the administration of extract of Urtica dioica leaves before induction of diabetic with streptozotocin has a protective effect on the morphometric alterations of hepatocytes in the periportal and perivenous zones of the liver lobule in rats.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

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

    2017-01-01

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

  20. Effects of hepatocyte growth factor on glutathione synthesis, growth, and apoptosis is cell density-dependent

    International Nuclear Information System (INIS)

    Yang Heping; Magilnick, Nathaniel; Xia Meng; Lu, Shelly C.

    2008-01-01

    Hepatocyte growth factor (HGF) is a potent hepatocyte mitogen that exerts opposing effects depending on cell density. Glutathione (GSH) is the main non-protein thiol in mammalian cells that modulates growth and apoptosis. We previously showed that GSH level is inversely related to cell density of hepatocytes and is positively related to growth. Our current work examined whether HGF can modulate GSH synthesis in a cell density-dependent manner and how GSH in turn influence HGF's effects. We found HGF treatment of H4IIE cells increased cell GSH levels only under subconfluent density. The increase in cell GSH under low density was due to increased transcription of GSH synthetic enzymes. This correlated with increased protein levels and nuclear binding activities of c-Jun, c-Fos, p65, p50, Nrf1 and Nrf2 to the promoter region of these genes. HGF acts as a mitogen in H4IIE cells under low cell density and protects against tumor necrosis factor α (TNFα)-induced apoptosis by limiting JNK activation. However, HGF is pro-apoptotic under high cell density and exacerbates TNFα-induced apoptosis by potentiating JNK activation. The increase in cell GSH under low cell density allows HGF to exert its full mitogenic effect but is not necessary for its anti-apoptotic effect

  1. Inhibition of DNA synthesis by chemical carcinogens in cultures of initiated and normal proliferating rat hepatocytes

    International Nuclear Information System (INIS)

    Novicki, D.L.; Rosenberg, M.R.; Michalopoulos, G.

    1985-01-01

    Rat hepatocytes in primary culture can be stimulated to replicate under the influence of rat serum and sparse plating conditions. Higher replication rates are induced by serum from two-thirds partially hepatectomized rats. The effects of carcinogens and noncarcinogens on the ability of hepatocytes to synthesize DNA were examined by measuring the incorporation of [3H]thymidine by liquid scintillation counting and autoradiography. Hepatocyte DNA synthesis was not decreased by ethanol or dimethyl sulfoxide at concentrations less than 0.5%. No effect was observed when 0.1 mM ketamine, Nembutal, hypoxanthine, sucrose, ascorbic acid, or benzo(e)pyrene was added to cultures of replicating hepatocytes. Estrogen, testosterone, tryptophan, and vitamin E inhibited DNA synthesis by approximately 50% at 0.1 mM, a concentration at which toxicity was noticeable. Several carcinogens requiring metabolic activation as well as the direct-acting carcinogen N-methyl-N'-nitro-N-nitrosoguanidine interfered with DNA synthesis. Aflatoxin B1 inhibited DNA synthesis by 50% (ID50) at concentrations between 1 X 10(-8) and 1 X 10(-7) M. The ID50 for 2-acetylaminofluorene was between 1 X 10(-7) and 1 X 10(-6) M. Benzo(a)pyrene and 3'-methyl-4-dimethylaminoazobenzene inhibited DNA synthesis 50% between 1 X 10(-5) and 1 X 10(-4) M. Diethylnitrosamine and dimethylnitrosamine (ID50 between 1 X 10(-4) and 5 X 10(-4) M) and 1- and 2-naphthylamine (ID50 between 1 X 10(-5) and 5 X 10(-4) M) caused inhibition of DNA synthesis at concentrations which overlapped with concentrations that caused measurable toxicity

  2. Arsenite Effects on Mitochondrial Bioenergetics in Human and Mouse Primary Hepatocytes Follow a Nonlinear Dose Response

    Directory of Open Access Journals (Sweden)

    Hemantkumar Chavan

    2017-01-01

    Full Text Available Arsenite is a known carcinogen and its exposure has been implicated in a variety of noncarcinogenic health concerns. Increased oxidative stress is thought to be the primary cause of arsenite toxicity and the toxic effect is thought to be linear with detrimental effects reported at all concentrations of arsenite. But the paradigm of linear dose response in arsenite toxicity is shifting. In the present study we demonstrate that arsenite effects on mitochondrial respiration in primary hepatocytes follow a nonlinear dose response. In vitro exposure of primary hepatocytes to an environmentally relevant, moderate level of arsenite results in increased oxidant production that appears to arise from changes in the expression and activity of respiratory Complex I of the mitochondrial proton circuit. In primary hepatocytes the excess oxidant production appears to elicit adaptive responses that promote resistance to oxidative stress and a propensity to increased proliferation. Taken together, these results suggest a nonlinear dose-response characteristic of arsenite with low-dose arsenite promoting adaptive responses in a process known as mitohormesis, with transient increase in ROS levels acting as transducers of arsenite-induced mitohormesis.

  3. Receptor-mediated uptake of low density lipoprotein stimulates bile acid synthesis by cultured rat hepatocytes

    International Nuclear Information System (INIS)

    Junker, L.H.; Davis, R.A.

    1989-01-01

    The cellular mechanisms responsible for the lipoprotein-mediated stimulation of bile acid synthesis in cultured rat hepatocytes were investigated. Adding 280 micrograms/ml of cholesterol in the form of human or rat low density lipoprotein (LDL) to the culture medium increased bile acid synthesis by 1.8- and 1.6-fold, respectively. As a result of the uptake of LDL, the synthesis of [14C]cholesterol from [2-14C]acetate was decreased and cellular cholesteryl ester mass was increased. Further studies demonstrated that rat apoE-free LDL and apoE-rich high density lipoprotein (HDL) both stimulated bile acid synthesis 1.5-fold, as well as inhibited the formation of [14C]cholesterol from [2-14C]acetate. Reductive methylation of LDL blocked the inhibition of cholesterol synthesis, as well as the stimulation of bile acid synthesis, suggesting that these processes require receptor-mediated uptake. To identify the receptors responsible, competitive binding studies using 125I-labeled apoE-free LDL and 125I-labeled apoE-rich HDL were performed. Both apoE-free LDL and apoE-rich HDL displayed an equal ability to compete for binding of the other, suggesting that a receptor or a group of receptors that recognizes both apolipoproteins is involved. Additional studies show that hepatocytes from cholestyramine-treated rats displayed 2.2- and 3.4-fold increases in the binding of apoE-free LDL and apoE-rich HDL, respectively. These data show for the first time that receptor-mediated uptake of LDL by the liver is intimately linked to processes activating bile acid synthesis

  4. 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

  5. The effect of pomelo citrus (Citrus maxima var. Nambangan), vitamin C and lycopene towards the number reduction of mice (Mus musculus) apoptotic hepatocyte caused of ochratoxin A

    Science.gov (United States)

    Badriyah, Hastuti, Utami Sri

    2017-06-01

    Foods can contaminated by some mycotoxin produced by molds. Ochratoxin A is a sort of mycotoxin that cause structural damage on hepatocytes. Pomelo citrus (Citrus maxima var. Nambangan) contain vitamin C and lycopene that have antioxidant character. This research is done to: 1)examine the effect of pomelo citrus juice, vitamin C, and lycopene treatment towards the number reduction of mice apoptotic hepatocytes caused by ochratoxin A exposure, 2)examine the effect of vitamin C mixed with lycopene treatment towards the number reduction of mice apoptotic hepatocytes caused by ochratoxin A exposure. The experimental group used male mice strain BALB-C in the age of three month and bodyweight 20-30 grams devided in 4 experiment group and control group. The experiment group I were administered pomelo citrus juice 0,5 ml/30 grams BW/day orally during 2 weeks and then administered with ochratoxin in the dose of 1 mg/kg BW during 1 week. The experiment group II were administered with vitamin C in the dose of 5,85 µg/30g BW with the same methods. The experiment group III were administered with lycopene in the dose of 0,1025 µg/30 g BW with the same methods. The experiment group IV were administered with vitamin C mixed with lycopene with the same methods. The control group were administered with ochratoxin A in the dose of 1 mg/kg BW per oral during 1 week. The apoptotic hepatocyte number were count by microscopic observation of hepatocyte slides from experiment group as well as control group with cytochemical staining. The research result shows that: 1) the pomelo citrus juice, vitamin C as well as lycopene administration could reduce the mice apoptotic hepatocyte number caused by ochratoxin A exposure, compared with the mice apoptotic hepatocyte number caused by ochratoxin A exposure only; 2) the vitamin C mixed with lycopene could reduce the mice apoptotic hepatocyte number caused by ochratoxin A exposure compared with the mice apoptotic hepatocyte number caused by

  6. Glycogen synthase activation by sugars in isolated hepatocytes.

    Science.gov (United States)

    Ciudad, C J; Carabaza, A; Bosch, F; Gòmez I Foix, A M; Guinovart, J J

    1988-07-01

    We have investigated the activation by sugars of glycogen synthase in relation to (i) phosphorylase a activity and (ii) changes in the intracellular concentration of glucose 6-phosphate and adenine nucleotides. All the sugars tested in this work present the common denominator of activating glycogen synthase. On the other hand, phosphorylase a activity is decreased by mannose and glucose, unchanged by galactose and xylitol, and increased by tagatose, glyceraldehyde, and fructose. Dihydroxyacetone exerts a biphasic effect on phosphorylase. These findings provide additional evidence proving that glycogen synthase can be activated regardless of the levels of phosphorylase a, clearly establishing that a nonsequential mechanism for the activation of glycogen synthase occurs in liver cells. The glycogen synthase activation state is related to the concentrations of glucose 6-phosphate and adenine nucleotides. In this respect, tagatose, glyceraldehyde, and fructose deplete ATP and increase AMP contents, whereas glucose, mannose, galactose, xylitol, and dihydroxyacetone do not alter the concentration of these nucleotides. In addition, all these sugars, except glyceraldehyde, increase the intracellular content of glucose 6-phosphate. The activation of glycogen synthase by sugars is reflected in decreases on both kinetic constants of the enzyme, M0.5 (for glucose 6-phosphate) and S0.5 (for UDP-glucose). We propose that hepatocyte glycogen synthase is activated by monosaccharides by a mechanism triggered by changes in glucose 6-phosphate and adenine nucleotide concentrations which have been described to modify glycogen synthase phosphatase activity. This mechanism represents a metabolite control of the sugar-induced activation of hepatocyte glycogen synthase.

  7. 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. Copyright © 2014. Published by Elsevier B.V.

  8. Effect of elevated total CoA levels on metabolic pathways in cultured hepatocytes

    International Nuclear Information System (INIS)

    Steffen, C.A.; Smith, C.M.

    1987-01-01

    Livers from fasted rats have 30% higher total CoA levels than fed rats. To determine whether this increase of total CoA influences metabolism, the rates of gluconeogenesis, fatty acid oxidation and ketogenesis were measured in hepatocytes with cyanamide (CYM) or pantothenate (PA) deficient medium used to vary total CoA levels independently of hormonal status. Primary cultures of rat hepatocytes were incubated 14 hrs with Bt 2 cAMP, dexamethasone + theophylline in PA deficient medium or with CYM (500 μM) + PA, rinsed and preincubated 0.5 hr to remove the CYM. Hepatocytes treated with CYM had total CoA levels 10-24% higher than PA deficient cells and lower rates of glucose production from lactate + pyruvate (L/P) or from alanine (0.23 +/- 0.05 and 0.089 +/- 0.02 μm/mg protein, respectively in CYM treated cells compared to 0.33 +/- 0.06 and 0.130 +/- 0.006 in PA deficient cells). This decrease was not due to CYM per se, as the direct addition of CYM stimulated glucose production from L/P. CYM treated cells with 15-40% higher total CoA and 30% higher fatty acyl-CoA levels had the same rates of [ 14 C]-palmitate oxidation as PA deficient cells. However, rates of ketogenesis were lower in CYM treated cells (163 +/- 11 nm/mg compared to 217 +/- 14 nm/mg protein). These results suggest that physiological alterations of hepatic total CoA levels are not necessary for fasting rates of gluconeogenesis, fatty acid oxidation and ketogenesis

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

    Czech Academy of Sciences Publication Activity Database

    Sobotka, O.; Endlicher, R.; Drahota, Zdeněk; Kučera, O.; Rychtrmoc, D.; Raad, M.; Hakeem, K.; Červinková, Z.

    2016-01-01

    Roč. 48, č. 4 (2016), s. 363-373 ISSN 0145-479X Institutional support: RVO:67985823 Keywords : 3-bromopyruvate * toxicity * liver * hepatocyte * mitochondria Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.576, year: 2016

  10. Two appendages homologous between basal bodies and centrioles are formed using distinct Odf2 domains.

    Science.gov (United States)

    Tateishi, Kazuhiro; Yamazaki, Yuji; Nishida, Tomoki; Watanabe, Shin; Kunimoto, Koshi; Ishikawa, Hiroaki; Tsukita, Sachiko

    2013-11-11

    Ciliogenesis is regulated by context-dependent cellular cues, including some transduced through appendage-like structures on ciliary basal bodies called transition fibers and basal feet. However, the molecular basis for this regulation is not fully understood. The Odf2 gene product, ODF2/cenexin, is essential for both ciliogenesis and the formation of the distal and subdistal appendages on centrioles, which become basal bodies. We examined the effects of Odf2 deletion constructs on ciliogenesis in Odf2-knockout F9 cells. Electron microscopy revealed that ciliogenesis and transition fiber formation required the ODF2/cenexin fragment containing amino acids (aa) 188-806, whereas basal foot formation required aa 1-59 and 188-806. These sequences also formed distal and subdistal appendages, respectively, indicating that the centriole appendages are molecularly analogous to those on basal bodies. We used the differential formation of appendages by Odf2 deletion constructs to study the incorporation and function of molecules associated with each appendage type. We found that transition fibers and distal appendages were required for ciliogenesis and subdistal appendages stabilized the centrosomal microtubules.

  11. The effects of diet-induced obesity on hepatocyte insulin signaling pathways and induction of non-alcoholic liver damage

    Directory of Open Access Journals (Sweden)

    Sameer Fatani

    2011-03-01

    Full Text Available Sameer Fatani1, Imose Itua2, Paul Clark3, Christopher Wong3, Ebrahim K Naderali21Obesity Biology Unit, School of Clinical Sciences, University of Liverpool, Liverpool, UK; 2Department of Health and Applied Social Sciences, Liverpool Hope University, Hope Park, Liverpool UK; 3Aintree University Hospital NHS Foundation Trust, Longmoor Lane, Liverpool, UKAbstract: The prevalence of diet-induced obesity is increasing amongst adults and children worldwide, predisposing millions of people to an array of health problems that include metabolic syndrome, non-alcoholic fatty liver disease and non-alcoholic steatohepatitis. In this study we used experimental animals to investigate the effects of dietary obesity on markers of hepatic insulin signaling as well as structural changes in hepatocytes. Adult male Wistar rats were randomized and assigned to either a control group or a test group. Controls were fed standard laboratory pelleted diet (chow-fed, while the test group had free access to a highly-palatable diet (HPD. After eight weeks, the HPD-fed animals were subdivided into three subgroups and their diets altered as follows: HPD-to-chow, HPD with the addition of fenofibrate given by oral gavage for a further seven weeks, or HPD with vehicle (1% carboxymethylcellulose at 1 mL/kg body weight given by oral gavage for a further seven weeks, respectively. Untreated diet-fed animals had significantly higher body weight, liver weight, and all measured metabolic profiles compared with chow-fed and treated diet-fed groups. Expression of kinases IRβ, IRS-1, AKt, eNOS, Shc and ERK1/2 were unaffected by obesity, while IRS-2 and P I3 kinase levels were significantly reduced in untreated HPD animals. Compared with chow-fed animals, steatosis and steatohepatitis were almost doubled in animals from untreated HPD, while removal of HPD and fenofibrate-treatment reduced steatosis by 40% and 80% respectively. These data suggest that diet-induced obesity affects

  12. Protective role of morin, a flavonoid, against high glucose induced oxidative stress mediated apoptosis in primary rat hepatocytes.

    Directory of Open Access Journals (Sweden)

    Radhika Kapoor

    Full Text Available Apoptosis is an early event of liver damage in diabetes and oxidative stress has been linked to accelerate the apoptosis in hepatocytes. Therefore, the compounds that can scavenge ROS may confer regulatory effects on high-glucose induced apoptosis. In the present study, primary rat hepatocytes were exposed to high concentration (40 mM of glucose. At this concentration decreased cell viability and enhanced ROS generation was observed. Depleted antioxidant status of hepatocytes under high glucose stress was also observed as evident from transcriptional level and activities of antioxidant enzymes. Further, mitochondrial depolarisation was accompanied by the loss of mitochondrial integrity and altered expression of Bax and Bcl-2. Increased translocation of apoptotic proteins like AIF (Apoptosis inducing factor & Endo-G (endonuclease-G from its resident place mitochondria to nucleus was also observed. Cyt-c residing in the inter-membrane space of mitochondria also translocated to cytoplasm. These apoptotic proteins initiated caspase activation, DNA fragmentation, chromatin condensation, increased apoptotic DNA content in glucose treated hepatocytes, suggesting mitochondria mediated apoptotic mode of cell death. Morin, a dietary flavonoid from Psidium guajava was effective in increasing the cell viability and decreasing the ROS level. It maintained mitochondrial integrity, inhibited release of apoptotic proteins from mitochondria, prevented DNA fragmentation, chromatin condensation and hypodiploid DNA upon exposure to high glucose. This study confirms the capacity of dietary flavonoid Morin in regulating apoptosis induced by high glucose via mitochondrial mediated pathway through intervention of oxidative stress.

  13. 17α-Ethinylestradiol (EE2) effect on global gene expression in primary rainbow trout (Oncorhynchus mykiss) hepatocytes

    International Nuclear Information System (INIS)

    Hultman, Maria T.; Song, You; Tollefsen, Knut Erik

    2015-01-01

    Highlights: • EE2 induced large scale transcriptional changes in primary hepatocytes. • Classical estrogen biomarkers were altered in a concentration-dependent manner. • EE2 altered biological processes related to lipid transport and reproduction. • EE2 interfered with lipid metabolism, biotransformation, and multidrug transport. • In vitro transcriptional changes were fairly similar to that observed in vivo. - Abstract: The potential impact of endocrine disrupting chemicals (EDCs) in the aquatic environment has driven the development of screening assays to evaluate the estrogenic properties of chemicals and their effects on aquatic organisms such as fish. However, obtaining full concentration–response relationships in animal (in vivo) exposure studies are laborious, costly and unethical, hence a need for developing feasible alternative (non-animal) methods. Use of in vitro bioassays such as primary fish hepatocytes, which retain many of the native properties of the liver, has been proposed for in vitro screening of estrogen receptor (ER) agonists and antagonists. The aim of present study was to characterize the molecular mode of action (MoA) of the ER agonist 17α-ethinylestradiol (EE2) in primary rainbow trout (Oncorhynchus mykiss) hepatocytes. A custom designed salmonid 60,000-feature (60k) oligonucleotide microarray was used to characterize the potential MoAs after 48 h exposure to EE2. The microarray analysis revealed several concentration-dependent gene expression alterations including classical estrogen sensitive biomarker gene expression (e.g. estrogen receptor α, vitellogenin, zona radiata). Gene Ontology (GO) analysis displayed transcriptional changes suggesting interference of cellular growth, fatty acid and lipid metabolism potentially mediated through the estrogen receptor (ER), which were proposed to be associated with modulation of genes involved in endocrine function and reproduction. Pathway analysis supported the identified GOs and

  14. 17α-Ethinylestradiol (EE2) effect on global gene expression in primary rainbow trout (Oncorhynchus mykiss) hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Hultman, Maria T., E-mail: mhu@niva.no [Norwegian Institute for Water Research (NIVA), Section of Ecotoxicology and Risk Assessment, Gaustadalléen 21, N-0349 Oslo (Norway); Faculty of Environmental Science & Technology, Department for Environmental Sciences, Norwegian University of Life Sciences (NMBU), Post box 5003, N-1432 Ås (Norway); Song, You [Norwegian Institute for Water Research (NIVA), Section of Ecotoxicology and Risk Assessment, Gaustadalléen 21, N-0349 Oslo (Norway); Tollefsen, Knut Erik [Norwegian Institute for Water Research (NIVA), Section of Ecotoxicology and Risk Assessment, Gaustadalléen 21, N-0349 Oslo (Norway); Faculty of Environmental Science & Technology, Department for Environmental Sciences, Norwegian University of Life Sciences (NMBU), Post box 5003, N-1432 Ås (Norway)

    2015-12-15

    Highlights: • EE2 induced large scale transcriptional changes in primary hepatocytes. • Classical estrogen biomarkers were altered in a concentration-dependent manner. • EE2 altered biological processes related to lipid transport and reproduction. • EE2 interfered with lipid metabolism, biotransformation, and multidrug transport. • In vitro transcriptional changes were fairly similar to that observed in vivo. - Abstract: The potential impact of endocrine disrupting chemicals (EDCs) in the aquatic environment has driven the development of screening assays to evaluate the estrogenic properties of chemicals and their effects on aquatic organisms such as fish. However, obtaining full concentration–response relationships in animal (in vivo) exposure studies are laborious, costly and unethical, hence a need for developing feasible alternative (non-animal) methods. Use of in vitro bioassays such as primary fish hepatocytes, which retain many of the native properties of the liver, has been proposed for in vitro screening of estrogen receptor (ER) agonists and antagonists. The aim of present study was to characterize the molecular mode of action (MoA) of the ER agonist 17α-ethinylestradiol (EE2) in primary rainbow trout (Oncorhynchus mykiss) hepatocytes. A custom designed salmonid 60,000-feature (60k) oligonucleotide microarray was used to characterize the potential MoAs after 48 h exposure to EE2. The microarray analysis revealed several concentration-dependent gene expression alterations including classical estrogen sensitive biomarker gene expression (e.g. estrogen receptor α, vitellogenin, zona radiata). Gene Ontology (GO) analysis displayed transcriptional changes suggesting interference of cellular growth, fatty acid and lipid metabolism potentially mediated through the estrogen receptor (ER), which were proposed to be associated with modulation of genes involved in endocrine function and reproduction. Pathway analysis supported the identified GOs and

  15. Hepatocyte CD81 is required for Plasmodium falciparum and Plasmodium yoelii sporozoite infectivity.

    NARCIS (Netherlands)

    Silvie, O.; Rubinstein, E.; Franetich, J.F.; Prenant, M.; Belnoue, E.; Renia, L.; Hannoun, L.; Eling, W.M.C.; Levy, S.; Boucheix, C.; Mazier, D.

    2003-01-01

    Plasmodium sporozoites are transmitted through the bite of infected mosquitoes and first invade the liver of the mammalian host, as an obligatory step of the life cycle of the malaria parasite. Within hepatocytes, Plasmodium sporozoites reside in a membrane-bound vacuole, where they differentiate

  16. HUMAN LIVER SLICES EXPRESS THE SAME LIDOCAINE BIOTRANSFORMATION RATE AS ISOLATED HUMAN HEPATOCYTES

    NARCIS (Netherlands)

    OLINGA, P; MEIJER, DKF; SLOOFF, MJH; GROOTHUIS, GMM; Merema, M.T.

    1993-01-01

    In order to investigate whether liver slices are a valuable tool for the assessment of drug metabolism in human liver, we compared the phase I metabolism of lidocaine in human liver slices and hepatocytes prepared from three human livers. Lidocaine is mainly metabolised to monoethylglycinexylidide

  17. Fatty acid and amino acid modulation of glucose cycling in isolated rat hepatocytes

    NARCIS (Netherlands)

    Gustafson, LA; Neeft, M; Reijngoud, DJ; Kuipers, F; Sauerwein, HP; Romijn, JA; Herling, AW; Burger, HJ; Meijer, AJ

    2001-01-01

    We studied the influence of glucose/glucose 6-phosphate cycling on glycogen deposition from glucose in fasted-rat hepatocytes using S4048 and CP320626, specific inhibitors of glucose-6-phosphate translocase and glycogen phosphorylase respectively. The effect of amino acids and oleate was also

  18. First characterization of AKB-48 metabolism, a novel synthetic cannabinoid, using human hepatocytes and high-resolution mass spectrometry.

    Science.gov (United States)

    Gandhi, Adarsh S; Zhu, Mingshe; Pang, Shaokun; Wohlfarth, Ariane; Scheidweiler, Karl B; Liu, Hua-Fen; Huestis, Marilyn A

    2013-10-01

    Since the federal authorities scheduled the first synthetic cannabinoids, JWH-018 and JWH-073, new synthetic cannabinoids were robustly marketed. N-(1-Adamantyl)-1-pentylindazole-3-carboxamide (AKB-48), also known as APINACA, was recently observed in Japanese herbal smoking blends. The National Forensic Laboratory Information System registered 443 reports of AKB-48 cases in the USA from March 2010 to January 2013. In May 2013, the Drug Enforcement Administration listed AKB-48 as a Schedule I drug. Recently, AKB-48 was shown to have twice the CB1 receptor binding affinity than CB2. These pharmacological effects and the difficulty in detecting the parent compound in urine highlight the importance of metabolite identification for developing analytical methods for clinical and forensic investigations. Using human hepatocytes and TripleTOF mass spectrometry, we identified 17 novel phase I and II AKB-48 metabolites, products of monohydroxylation, dihydroxylation, or trihydroxylation on the aliphatic adamantane ring or N-pentyl side chain. Glucuronide conjugation of some mono- and dihydroxylated metabolites also occurred. Oxidation and dihydroxylation on the adamantane ring and N-pentyl side chain formed a ketone. More metabolites were identified after 3 h of incubation than at 1 h. For the first time, we present a AKB-48 metabolic scheme obtained from human hepatocytes and high-resolution mass spectrometry. These data are needed to develop analytical methods to identify AKB-48 consumption in clinical and forensic testing.

  19. Roux-en Y gastric bypass results in long-term remission of hepatocyte apoptosis and hepatic histological features of non-alcoholic steatohepatitis

    Directory of Open Access Journals (Sweden)

    Anne-Sophie Schneck

    2016-08-01

    Full Text Available The long-term effects of bariatric surgery on non alcoholic steatohepatitis (NASH, focusing on liver injury and hepatocyte apoptosis,are not well established. We here performed a longitudinal study with paired liver biopsies of 9 morbidly obese women (median BMI: 42 [38.7; 45.1] kg/m2 with NASH with a median follow-up of 55 [44; 75] months after laparoscopic Roux-en-Y gastric bypass (LRYGB surgery. LRYGB surgery was associated with significant weight loss (median BMI loss –13.7 [–16.4; –9.5] kg/m2, improved hepatic steatosis in all patients (55.5% with total resolution, and resolution of hepatic inflammation and hepatocyte ballooning in 100% and 88.8% of cases, respectively. Alanine aminotransferase levels dropped to normal values while hepatic activated cleaved caspase 3levels strongly decreased after a median follow-up of 55 months. Hepatocyte apoptosis, as evaluated by serum caspase-generated keratin-18 fragment, improved within the first year following LRYGB and these improvements persisted for at least 55 months. LRYGB in morbidly obese patients with NASH is thus associated with a long-lasting beneficial impact on hepatic steatohepatitis and hepatocyte death.

  20. Roux-En Y Gastric Bypass Results in Long-Term Remission of Hepatocyte Apoptosis and Hepatic Histological Features of Non-alcoholic Steatohepatitis.

    Science.gov (United States)

    Schneck, Anne-Sophie; Anty, Rodolphe; Patouraux, Stéphanie; Bonnafous, Stéphanie; Rousseau, Déborah; Lebeaupin, Cynthia; Bailly-Maitre, Beatrice; Sans, Arnaud; Tran, Albert; Gugenheim, Jean; Iannelli, Antonio; Gual, Philippe

    2016-01-01

    The long-term effects of bariatric surgery on non-alcoholic steatohepatitis (NASH), focusing on liver injury and hepatocyte apoptosis, are not well-established. We here performed a longitudinal study with paired liver biopsies of nine morbidly obese women (median BMI: 42 [38.7; 45.1] kg/m(2)) with NASH with a median follow-up of 55 [44; 75] months after laparoscopic Roux-en-Y gastric bypass (LRYGB) surgery. LRYGB surgery was associated with significant weight loss (median BMI loss -13.7 [-16.4; -9.5] kg/m(2)), improved hepatic steatosis in all patients (55.5% with total resolution), and resolution of hepatic inflammation and hepatocyte ballooning in 100 and 88.8% of cases, respectively. Alanine aminotransferase levels dropped to normal values while hepatic activated cleaved caspase-3 levels strongly decreased after a median follow-up of 55 months. Hepatocyte apoptosis, as evaluated by serum caspase-generated keratin-18 fragment, improved within the first year following LRYGB and these improvements persisted for at least 55 months. LRYGB in morbidly obese patients with NASH is thus associated with a long-lasting beneficial impact on hepatic steatohepatitis and hepatocyte death.