Liver Cell Function Research Articles

Co‐culture with mesenchymal stem cells enhances metabolic functions of liver cells in bioartificial liver system

Bioartificial liver provides a combination of three-dimensional support, matrix interactions, and extracellular cues to create a bio-mimic microenvironment for maintaining hepatic-specific functions of liver cells in vitro. However, its transformal and metabolic functions are not yet satisfactory for clinic application. In this study, hepatoma-derived C3A cells were co-cultured with human placental mesenchymal stem cells (hPMSC) in microspheres placed in a fluidized bioreactor. The secretion of albumin and urea, the expression of metabolizing enzymes at both transcriptional and translational levels and the drug metabolism functions of co-cultured C3A cells were determined. With the three-dimensional culture system, when C3A cells were co-cultured with hPMSCs in separate microspheres, the secretion of albumin and activity of CYP1A2 were significantly improved although the enhancement of urea synthesis and CYP3A4 activity was less prominent. Combining co-culture system with fluidization significantly increased the secretion of urea and the activities of CYP1A2, CYP3A4 but not the albumin synthesis. Interestingly, the levels of phospho-PKA (Thr 197), phospho-PKC, phospho-ERK1/2 (Thr 202/Tyr 204) and CaMKII were all found to decrease in co-cultured C3A cells, implicating suppressed signaling pathways in those cells. Taken together, our results suggest that co-culturing of liver cells with hPMSC cells in three-dimensional fluidized bioreactor significantly improved the preservation of liver cells' metabolic functions which may greatly enhance the efficacy of bioartificial liver treatment.

Application of selective and timely regional hepatic vascular occlusion for resection of large centrally located liver tumors: report of 133 cases

To improve the resection rate and increase operation safety for large centrally located liver tumors. Clinical data from 133 patients with large centrally located liver tumors confirmed by surgery were analyzed retrospectively. Selective and timely regional hepatic vascular occlusion was used during the operation procedure. The resection rate was 100%. Perioperative death occurred in one patient. During operations, Forty-four patients underwent regional hepatic inflow occlusion ranging from 12 to 33 minutes. Twenty-three patients underwent left and right inflow occlusion, respectively, ranging from 8 to 50 minutes. One patient had right half-hepatic vascular exclusion for 40 minutes. The blood loss of 132 patients was (665 ± 424) ml (one patient experienced diffuse blood oozing and died in the next day). Among them, the blood loss of patients with liver cirrhosis was (723 ± 479) ml. On the contrary, those without liver cirrhosis was (458 ± 223) ml (P < 0.01). Liver function in 92.4% (122/132) patients recovered to Child-Pugh A within one week. No liver failure occurred. After operation, 3 patients presented ascites. Among them, two patients had liver cirrhosis and hepatocellular jaundice, one patient was accepted for transcatheter arterial chemoembolization preoperatively. Four patients had biliary fistula, one patient had gastroparesis, one patient had thrombus in the superior mesenteric vein and portal vein, and five patients had right pleural effusion. The 1-, 3- and 5-year survival rates of 112 patients were 89.1%, 57.7% and 36.9%, respectively. Selective and timely regional hepatic vascular occlusion is useful for the resection of large centrally located liver tumors. This kind of procedure can effectively control the blood loss during the operation and shorten the ischemic reperfusion time, beneficial for protecting the liver cell function. This procedure is a safe hepatic flow occlusion method.

Physiological roles of N-acetylglucosaminyltransferase V (GnT-V) in mice

Oligosaccharide modification by N-acetylglucosaminyltransferase- V (GnT-V), a glycosyltransferase encoded by the Mgat5 gene that catalyzes the formation of β1,6GlcNAc (N-acetylglucosamine) branches on N-glycans, is thought to be associated with cancer growth and metastasis. Overexpression of GnT-V in cancer cells enhances the signaling of growth factors such as epidermal growth factor by increasing galectin-3 binding to polylactosamine structures on receptor N-glycans. In contrast, GnT-V deficient mice are born healthy and lack β1,6GlcNAc branches on N-glycans, but develop immunological disorders due to T-cell dysfunction at 12-20 months of age. We have developed Mgat5 transgenic (Tg) mice (GnT-V Tg mice) using a β-actin promoter and found characteristic phenotypes in skin, liver, and T cells in the mice. Although the GnT-V Tg mice do not develop spontaneous cancers in any organs, there are differences in the response to external stimuli between wild-type and GnT-V Tg mice. These changes are similar to those seen in cancer progression but are unexpected in some aspects. In this review, we summarize what is known about GnT-V functions in skin and liver cells as a means to understand the physiological roles of GnT-V in mice.

Effects of statins on liver cell function and inflammation in septic rats

BackgroundSeveral studies suggest that the presence of statins may be beneficial during sepsis, but this idea is controversial. The aim of this study was to investigate the effects of long-term statin treatment in the livers of septic animals, focusing on its antioxidant, antiinflammatory, and metabolic properties. Materials and methodsMale Wistar rats were treated orally with simvastatin, atorvastatin, or vehicle once a d. After 30 d, sepsis was induced by cecal ligation and puncture (CLP) in Control, Simvastatin-treated, and Atorvastatin-treated groups, while the Sham group underwent only laparotomy. The Basal Simvastatin and Basal Atorvastatin groups received only their respective drugs without surgery. Twenty-four h after CLP or laparotomy, samples were collected from anesthetized rats for evaluation of hepatic oxidative stress, liver histology, hepatic mitochondria enzyme activity, leukocyte counts in blood and peritoneal cavity, gene expression of hepatic superoxide dismutase and TNF-2, and plasma biochemistry. ResultsMost parameters that we tested exhibited expected changes upon sepsis induction. However, statin treatment only improved liver mitochondrial enzymatic activity. In other parameters, simvastatin and atorvastatin failed to protect the liver against injuries incurred upon the CLP-induced polymicrobial sepsis model. ConclusionsPretreatment with simvastatin or atorvastatin alone before sepsis induction improved mitochondrial activity in the liver; however, this result was not reproduced in other biomarkers of liver function and leukocyte migration during sepsis. Future studies should be performed to evaluate whether statins can be combined with other drugs to increase the efficacy of sepsis therapy.

Evaluation of Organic Anion-Transporting Polypeptide 1B1 and CYP3A4 Activities in Primary Human Hepatocytes and HepaRG Cells Cultured in a Dynamic Three-Dimensional Bioreactor System

The long-term stability of liver cell functions is a major challenge when studying hepatic drug transport, metabolism, and toxicity in vitro. The aim of the present study was to investigate organic anion-transporting polypeptide (OATP) 1B1 and CYP3A4 activities in fresh primary human hepatocytes and differentiated cryopreserved HepaRG cells when cultured in a three-dimensional (3D) bioreactor system. OATP1B1 activity was determined by loss from media experiments of [(3)H]estradiol-17β-D-glucuronide and atorvastatin acid (ATA) for up to 7 days in culture. ATA metabolite formation was determined at days 3 to 4 to evaluate CYP3A4 activity. Overall, the results showed that freshly isolated human hepatocytes inoculated in the bioreactor retained OATP1B1 activity for at least 7 days, whereas in HepaRG cells no OATP1B1 activity was observed beyond day 2. The activity data were in agreement with immunohistochemical stainings, which showed that OATP1B1 protein expression was preserved for at least 9 days in fresh human hepatocytes, whereas OATP1B1 was expressed markedly lower in HepaRG cells after 9 days in culture. Fresh human hepatocytes and HepaRG cells exhibited similar CYP3A4 activity in bioreactor culture, and immunohistochemical stainings supported these findings. Activity and mRNA expression of OATP1B1 and CYP3A4 in primary human hepatocytes compared with HepaRG cells in fresh suspensions were in agreement with data obtained in bioreactor culture. In conclusion, freshly isolated human hepatocytes cultured in a 3D bioreactor system preserve both OATP1B1 and CYP3A4 activities, allowing long-term in vitro studies on drug disposition and toxicity.

Study on hepatotoxicity of aqueous extracts of Polygonum multiflorum in rats after 28-day oral administration-analysis on correlation of cholestasis

To observe the liver injury degree of SD rats after 28-day administration of aqueous extracts of Polygonum multiflorum (AEPM) and the correlation with cholestasis mechanism. Adult SD rats were orally administered with 30, 60 g x kg(-1) of APEM once every day for 28 d. After 28 d, the general condition of rats such as weight were observed, liver function-related indicators were detected. Bile was collected to determine total bile acid output, flow rate and density and changes in major compositions. Their livers were weighed then sent for histopathological examination. AEPM did not change the general conditions and weights of rats. From the results of the related indicators of liver function and cholestasis, AEPM did not change the contents of ALT and AST in serum, but high dose of AEPM can increase the contents of ALP, GGT and TBA in serum (P < 0.05, P < 0.01) and decrease the content of TBIL in serum (P < 0.05). And the contents of GGT in serum of low dose rats were increased (P < 0.05). The bile flow was not changed by AEPM, but bile compositions of high dose male rats were obviously changed (TG increase, TBIL decrease, TBA decrease). The weights of liver and ratio of liver of the high dose rats were increased but showed no statistical significance. Pathologic examination displayed that there were only small pieces of necrosis in livers of several rats, without any severe disease. AEPM can obviously injure bile duct epithelial cells, intervene liver cell functions and change bile compositions in rats, thus it is proved to induce cholestasis without severe liver injury.

Tissue specific synthetic ECM hydrogels for 3-D in vitro maintenance of hepatocyte function

Despite recent advances in biomaterial science, there is yet no culture system that supports long-term culture expansion of human adult hepatocytes, while preserving continued function. Previous studies suggested that acellular liver extracellular matrix (ECM), employed as a substrate, improved proliferation and function of liver cells. Here we investigated whether extracts prepared from acellular liver ECM (liver ECM extract, LEE), or from whole (fresh) liver tissue (liver tissue extract, LTE), could be combined with collagen Type I, hyaluronic acid (HA), or heparin-conjugated HA (HP) hydrogels to enhance survival and functional output of primary human hepatocytes. The liver-specific semi-synthetic ECMs (sECMs) were prepared by incorporating LEE or LTE into the gel matrices. Subsequently, primary human hepatocytes were maintained in sandwich-style hydrogel cultures for 4 weeks. Progressive increase in hepatocyte metabolism was observed in all HA and HP groups. Hepatocytes cultured in HA and HP hydrogels containing LEE or LTE synthesized and secreted steady levels of albumin and urea and sustained cytochrome p450-dependent drug metabolism of ethoxycoumarin. Collectively, these results indicate that customized HA hydrogels with liver-specific ECM components may be an efficient method for expansion human hepatocytes in vitro for cell therapy and drug and toxicology screening purposes.

Silica nanoparticles and silver-doped silica nanoparticles induce endoplasmatic reticulum stress response and alter cytochrome P4501A activity

Engineered silica nanoparticles (SiO2-NPs) find widespread application and may lead to exposure of humans and the environment. Here we compare the effects of SiO2-NPs and SiO2-NPs doped with silver (SiO2–Ag-NPs) on survival and cellular function of human liver cells (Huh7) and Pimephales promelas (fathead minnow) fibroblast cells (FMH). In Huh7 cells we investigate effects on the endoplasmatic reticulum (ER), including ER stress, and interactions of nanoparticles (NPs) with metabolizing enzymes and efflux transporters. The NPs formed agglomerates/aggregates in cell culture media as revealed by SEM and TEM. SiO2 and SiO2–1% Ag-NPs were taken up into cells as demonstrated by agglomerates occurring in vesicular-like structures or freely dispersed in the cytosol. Cytotoxicity was more pronounced in Huh7 than in FMH cells, and increased with silver content in silver-doped NPs. Dissolved silver was the most significant factor for cytotoxicity. At toxic and non-cytotoxic concentrations SiO2-NPs and SiO2–1% Ag-NPs induced perturbations in the function of ER. In Huh7 cells NPs induced the unfolded protein response (UPR), or ER stress response, as demonstrated in induced expression of BiP and splicing of XBP1 mRNA, two selective markers of ER stress. Additionally, SiO2–1% Ag-NPs and AgNO3 induced reactive oxygen species. Pre-treatment of Huh7 cells with SiO2–1% Ag-NPs followed by exposure to the inducer benzo(a)pyrene caused a significant reduced induction of CYP1A activity. NPs did not alter the activity of ABC transporters. These data demonstrate for the first time that SiO2-NPs and SiO2–1% Ag-NPs result in perturbations of the ER leading to the ER stress response. This represents a novel and significant cellular signalling pathway contributing to the cytotoxicity of NPs.

Participation of liver progenitor cells in liver regeneration: lack of evidence in the AAF/PH rat model

When hepatocyte proliferation is impaired, liver progenitor cells (LPC) are activated to participate in liver regeneration. We used the 2-acetaminofluorene/partial hepatectomy (AAF/PH) model to evaluate the contribution of LPC to liver cell replacement and function restoration. Fischer rats subjected to AAF/PH (or PH alone) were investigated 7, 10 and 14 days post-hepatectomy. Liver mass recovery (LMR) was estimated, and the liver mass to body weight ratio calculated. We used serum albumin and bilirubin levels, and liver albumin mRNA levels to assess the liver function. LPC expansion was analyzed by cytokeratin 19 (CK19), glutathione S-transferase protein (GSTp) immunohistochemistry and by CK19, CD133, transforming growth factor-β1 and hepatocyte growth factor mRNA expression in livers. Cell proliferation was evaluated by Ki67 and BrdU immunostaining. Compared with PH alone where LMR was ∼100% 14 days post-PH, LMR was defective in AAF/PH rats (64.1±15.5%, P=0.0004). LPC expansion was scarce in PH livers (0.5±0.4% of CK19+ area), but significant in AAF/PH livers (8.5±7.2% of CK19+), and inversely correlated to LMR (r2=0.63, P<0.0001). A quarter of AAF/PH animals presented liver failure (low serum albumin and high serum bilirubin) 14 days post-PH. Compared with animals with preserved function, this was associated with a lower LMR (50±6.8 vs 74.6±9.4%, P=0.0005), a decreased liver to body weight ratio (2±0.3 vs 3.5±0.6%, P=0.001), and a larger LPC expansion such as proliferating Ki67+ LPC covered 17.4±4.2% of the liver parenchyma vs 3.1±1.5%, (P<0.0001). Amongst those, rare LPC with an intermediate hepatocyte-like phenotype were seen. Also, less than 2% of hepatocytes were engaged into the cell cycle (Ki67+), while more numerous (∼25% of hepatocytes) in the livers with preserved function. These observations suggest that, in this model, the efficient recovery of the liver function was ensured rather by the proliferation of mature hepatocytes than by the LPC expansion and differentiation into hepatocytes.

A comparative study of the restorative effects of ocimum gratissimum and ocimum canum on alcohol induced hepatotoxicity in albino rats

Many species of Ocimum possess anti -inflammatory, antioxidant and anti -microbial properties and the plants are widely used in Ayurveda. The oxidative stress induced by ethanol consumption had been implicated the changes in the structure and functions of liver cells especially the membrane phospholipids leading to lipid peroxidation. This study was to assess the curative potential of the methanol extract of two different species of Ocimum , O. canum and O. gratissimum on alcohol induced hepatotoxicity in albino rats. Male Wister rats of body weight 200- 250 g , were divided into 6 groups of six rats each as (1) NC - normal control with normal diet (2) EC - alcohol control fed on alcohol for thirty days ; (3) EX -1 MEO G (methanol extract of Ocimum grat issimum ) only to check the toxicity of the extract , (4) EX - 2 MEOC (methanol extract of Ocimum canum ) only to check whether the extract had any toxic effect of its own and (5) EX - 3 MEOG after treating with ethanol for thirty days and confirming the hepatotoxicity, and (6) EX - 4 MEOC after the ethanol treatment . The rats were sacrificed after 30 days, and the blood collected for biochemical estimations . The results indicated that there were significant difference between the experimental rats (EX -groups) when compared with alcohol control (EC - group) in all the parameters checked and they were not significantly different from the normal control (NC -group) . The curative effect was established in groups 5 and 6, which showed a significant difference in antioxidant levels of all the parameters checked and retrieved its antioxidant status almost to the normal control. To come to the absolute normal condition of antioxidant levels it might have been needed a prolonged treatment for a longer period. Again, the groups, treated with extracts only, did not show any negative effect, which clearly indicated that the extract had no toxic effects. The use of antioxidant is an important preventive and curative method to minimize the pathological and toxic effects of oxidative stress induced by ethanol toxicity. Thus from the result obtained we conclude that MEOG and MEOC could effectively restore the antioxidant system from the oxidative stress induced by ethanol toxicity. In addition, there were no significant differences between the curative effects of these two species of Ocimum in terms of their effect on oxidative stress induced by ethanol toxicity.

Single-Cell Analysis of Ploidy and Centrosomes Underscores the Peculiarity of Normal Hepatocytes

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.

Three-dimensional culture of hepatocytes on porcine liver tissue-derived extracellular matrix

There is currently no optimal system to expand and maintain the function of human adult hepatocytes in culture. Recent studies have demonstrated that specific tissue-derived extracellular matrix (ECM) can serve as a culture substrate and that cells tend to proliferate and differentiate best on ECM derived from their tissue of origin. The goal of this study was to investigate whether three-dimensional (3D) ECM derived from porcine liver can facilitate the growth and maintenance of physiological functions of liver cells. Optimized decellularization/oxidation procedures removed up to 93% of the cellular components from porcine liver tissue and preserved key molecular components in the ECM, including collagen-I, -III, and -IV, proteoglycans, glycosaminoglycans, fibronectin, elastin, and laminin. When HepG2 cells or human hepatocytes were seeded onto ECM discs, uniform multi-layer constructs of both cell types were formed. Dynamic culture conditions yielded better cellular infiltration into the ECM discs. Human hepatocytes cultured on ECM discs expressed significantly higher levels of albumin over a 21-day culture period compared to cells cultured in traditional polystyrene cultureware or in a collagen gel “sandwich”. The culture of hepatocytes on 3D liver-specific ECM resulted in considerably improved cell growth and maintained cell function; therefore, this system could potentially be used in liver tissue regeneration, drug discovery or toxicology studies.

The effect of acute exposure to herbicide Gardoprim Plus Gold 500 SC on haematological and biochemical indicators and histopathological changes in common carp (Cyprinus carpio L.)

The study was focused on the assessment of effects of herbicide preparation Gardoprim Plus Gold 500 SC (terbuthylazine and S-metolachlor as active substances) on haematological and biochemical indices as well as tissue histopathological changes in common carp (Cyprinus carpio L.). Forty eight one- to two-year-old fish were divided into two groups, i.e. 24 fish were treated with 13.0 mg·l-1 of Gardoprim Plus Gold 500 SC and 24 fish were used in control. The experiment was conducted according to OECD method No. 203 Fish, Acute Toxicity Test. Experimental carp showed a significant decrease in leukocyte and lymphocyte counts (P &lt; 0.01) and haematocrit value (P &lt; 0.05) in haematological profile. In biochemical indices, a significant increase in glucose, aspartate aminotransferase, ammonia (P &lt; 0.01), and lactate dehydrogenase (P &lt; 0.05) and a significant decrease in inorganic phosphorus, triglycerides (P &lt; 0.01), and chlorides (P &lt; 0.05) were found in exposed carp compared to control. Histopathological examination revealed lesions in gills and liver. The decline in both leukocyte and lymphocyte counts indicates decreased nonspecific immunity of treated common carp. Increase in ammonia and glucose concentrations, and in catalytic activities of lactate dehydrogenase and aspartate aminotransferase can be related to stress burden, and alteration of liver cell function, respectively, in experimental carp compared to control fish. The study uniquely contributes to the evaluation of the effect of two-component herbicide preparation on common carp.

Serum fetuin A/α2HS-glycoprotein levels in patients with non-alcoholic fatty liver disease: relation with liver fibrosis

Serum concentrations of fetuin A/α2HS-glycoprotein (AHSG) have been linked to human metabolic alterations and can serve as an indicator of liver cell function. We assayed serum levels of AHSG in patients with non-alcoholic fatty liver disease (NAFLD), a hepatic manifestation of the metabolic syndrome, and examined their association with clinical, biochemical and histological phenotypes. Serum AHSG levels were determined by enzyme linked immunosorbent assay in 99 patients with biopsy-proven NAFLD and 75 age- and gender-matched controls. Serum AHSG levels were significantly higher in patients with NAFLD (940 ± 120 μg/mL) compared with healthy controls (800 ± 130 μg/mL, Student's t test, P < 0.001). Bivariate analyses (Spearman's rank correlation) in patients with NAFLD showed a statistically significant association between AHSG levels and insulin resistance as assessed by the HOMA (homeostasis model assessment) index (r = 0.31, P < 0.01) and the liver fibrosis score index (r = 0.36, P < 0.001). The association between AHSG and fibrosis remained statistically significant even after adjustment for potential confounders, including the HOMA index ([beta] = 1.65, t = 2.38, P < 0.05). Serum AHSG levels are significantly increased in adult patients with biopsy-proven NAFLD and are associated with insulin resistance. Importantly, our pilot data indicate that serum AHSG levels may identify NAFLD patients with higher fibrosis scores.

Liver-Assist Device With a Microfluidics-Based Vascular Bed in an Animal Model

This study evaluates a novel liver-assist device platform with a microfluidics-modeled vascular network in a femoral arteriovenous shunt in rats. Liver-assist devices in clinical trials that use pumps to force separated plasma through packed beds of parenchymal cells exhibited significant necrosis with a negative impact on function. Microelectromechanical systems technology was used to design and fabricate a liver-assist device with a vascular network that supports a hepatic parenchymal compartment through a nanoporous membrane. Sixteen devices with rat primary hepatocytes and 12 with human HepG2/C3A cells were tested in athymic rats in a femoral arteriovenous shunt model. Several parenchymal tube configurations were evaluated for pressure profile and cell survival. The blood flow pattern and perfusion status of the devices was examined by laser Doppler scanning. Cell viability and serum protein secretion functions were assessed. Femoral arteriovenous shunt was successfully established in all animals. Blood flow was homogeneous through the vascular bed and replicated native flow patterns. Survival of seeded liver cells was highly dependent on parenchymal chamber pressures. The tube configuration that generated the lowest pressure supported excellent cell survival and function. This device is the first to incorporate a microfluidics network in the systemic circulatory system. The microvascular network supported viability and function of liver cells in a short-term ex vivo model. Parenchymal chamber pressure generated in an arteriovenous shunt model is a critical parameter that affects viability and must be considered in future designs. The microfluidics-based vascular network is a promising platform for generating a large-scale medical device capable of augmenting liver function in a clinical setting.

QSG‐7701 human hepatocytes form polarized acini in three‐dimensional culture

Hepatocytes are polarized and fulfill a variety of liver-specific functions in vivo; but the polarized tissue structure and many of these functions are lost when the cells are cultured on plastic. To recapitulate the polarized structure and tissue-specific function of liver cells in culture, we established a three-dimensional (3D) culture assay with the human hepatocyte line QSG-7701. In 3D Matrigel culture, QSG-7701 cells formed polarized spheroids with a center lumen, which is reminiscent of bile canaliculi in the liver. Immunofluoresence analysis showed that F-actin bundles and radixin were mainly located at the apical membrane and that alpha6 and beta1 integrins were localized basally in 3D culture. Lumen formation was associated with the selective apoptosis of centrally located cells and was accompanied by proliferative suppression during acinar development. Compared to QSG-7701 cells in 2D or agarose gel cultures, the cells in 3D Matrigel culture maintained a given direction of biliary excretion and acquired higher levels of cytochrome P450 and albumin expression. Our study shows that the immortal human hepatocytes, QSG-7701, in 3D Matrigel culture reacquire cardinal features of glandular epithelium in vivo, providing an ex vivo model to study liver-specific function and tumorigenesis.

Pseudolesion of the liver observed on gadoxetate disodium-enhanced magnetic resonance imaging obtained shortly after transarterial chemoembolization for hepatocellular carcinoma

The purpose of this report was to describe pseudolesions of the liver that mimicked residual hypervascular hepatocellular carcinoma (HCC), as observed on gadoxetate disodium-enhanced magnetic resonance imaging (EOB-MRI) obtained shortly after transarterial chemoembolization (TACE). Between June 2008 and December 2008, three patients underwent MRI within 12 days after TACE to rule out remaining viable cancerous tissue or to assess the treatment effect. In all three patients, nontumorous liver tissue adjacent to the treated HCC exhibited focal arterial enhancement on dynamic phase and subsequent diminished uptake of gadoxetate disodium on hepatocellular phase images, which mimicked residual HCC. All three patients had mild postembolization syndrome at the time of EOB-MRI and showed no evidence of residual or recurrent tumors on follow-up. The findings of these areas may represent transient focal hyperemia and damage to the liver cell function caused by TACE. Radiologists should be aware that EOB-MRI obtained shortly after TACE may show pseudolesions around the treated tumors and should not mistake them for residual or recurrent tumors.

Relationship Between Liver Function and Liver Signal Intensity in Hepatobiliary Phase of Gadolinium Ethoxybenzyl Diethylenetriamine Pentaacetic Acid-Enhanced Magnetic Resonance Imaging

To evaluate the effect of liver function on liver signal intensity in gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging in humans and to examine the biochemical factors related to signal intensity in the hepatobiliary phase. This study included 48 patients with suspected hepatocellular carcinoma or metachronous liver metastases from colorectal cancer. The patients were divided into 2 groups: the chronic liver dysfunction and the normal liver function. All the individuals of both groups had magnetic resonance imaging before injection and at 5, 10, 15, 20, 25, and 30 minutes after bolus administration of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid. The time point when the mean liver signal-to-noise ratio (SNR) reached a peak was determined for each group, and the mean liver SNR at the peak point was compared between the groups. In all the patients, stepwise multivariate analysis was used to evaluate the relationship between the liver SNR at the peak time point and the laboratory data, using the following biochemical factors: prothrombin time, total bilirubin level, cholinesterase level, albumin level, creatinine level, indocyanine green retention rate at 15 minutes, and Child-Pugh score. The mean values of liver SNR increased gradually. The mean liver SNR reached peak at 30 minutes after contrast injection in both groups and was significantly lower in the chronic liver dysfunction group than in the normal liver function group. Indocyanine green retention rate at 15 minutes was the only significant contributor to the liver signal intensity at the peak time point (30 minutes). The degree of liver enhancement in the hepatobiliary phase may reflect liver cell function. The measurement of liver signal intensity in the hepatobiliary phase may be useful in predicting whole and regional hepatic functional reserves.

447 THE SCAVENGER RECEPTOR CLEVER-1 PLAYS A ROLE IN THE TRANSMIGRATION OF CD4 LYMPHOCYTES AND B CELLS ACROSS HEPATIC SINUSOIDAL ENDOTHELIUM

and reporter gene assays, respectively. Expression of cell surface markers (CD80, CD86, CD40, MHC-II) were assessed by FACS. Results: TLR3 induced stimulation of antiviral activities; IFN production and expression of interferon-stimulated genes in NPC were potently suppressed by pretreatment with IL-10 or TGF-b. This correlated with suppression of TLR3 receptor expression and inhibition of TLR-induced activation of NF-uB and IRF-3 in these cells. T cell activation induced by TLR3-stimulated NPC was suppressed by IL-10 and TGF-b which was associated with a downregulation of costimulatory cell surface molecules (CD80, CD86). Conclusions: HCV/TLR3-mediated innate and adaptive immune functions of non-parenchymal liver cells are potently controlled by IL-10 and TGF-b. This is of relevance for the regulation of the local immune responses against viral infections of the liver and the pathogenesis of HCV infection in particular.

Liver Cell Culture Devices.

In the last 15 years many different liver cell culture devices, consisting of functional liver cells and artificial materials, have been developed. They have been devised for numerous different applications, such as temporary organ replacement (a bridge to liver transplantation or native liver regeneration) and as in vitro screening systems in the early stages of the drug development process, like assessing hepatotoxicity, hepatic drug metabolism, and induction/inhibition studies. Relevant literature is summarized about artificial human liver cell culture systems by scrutinizing PubMed from 2003 to 2009. Existing devices are divided in 2D configurations (e.g., static monolayer, sandwich, perfused cells, and flat plate) and 3D configurations (e.g., liver slices, spheroids, and different types of bioreactors). The essential features of an ideal liver cell culture system are discussed: different types of scaffolds, oxygenation systems, extracellular matrixes (natural and artificial), cocultures with nonparenchymal cells, and the role of shear stress problems. Finally, miniaturization and high-throughput systems are discussed. All these factors contribute in their own way to the viability and functionality of liver cells in culture. Depending on the aim for which they are designed, several good systems are available for predicting hepatotoxicity and hepatic metabolism within the general population. To predict hepatotoxicity in individual cases genomic analysis might be essential as well.