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1.
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.  相似文献   

2.
Primary hepatocytes cultured as monolayers or as spheroids were studied to compare the effects of four different culture media (Williams' E, Chee's, Sigma Hepatocyte, and HepatoZYME medium). Rat hepatocytes were cultured as conventional monolayers for 3 d or as spheroids for 2 wk. For spheroid formation a method was emplOyed that combined the use of a nonadherent substratum with rotation of cultures. Hepatocyte integrity and morphology were assessed by light and electron microscopy and by reduced glutathione content. Hepatocyte function was measured by albumin secretion and 7-ethoxycoumarin metabolism. Chee's medium was found to be optimal for maintenance of hepatocyte viability and function in monolayers, but it failed to support spheroid formation. For spheroid formation and for the maintenance of spheroid morphology and function, Sigma HM was found to be optimal. These results demonstrate that the medium requirements of hepatocytes differ markedly depending on the culture model employed. Spheroid culture allowed better preservation of morphology and function of hepatocytes compared with conventional monolayer culture. Hepatocytes in spheroids formed bile canaliculi. and expressed an actin distribution resembling that found in hepatocytes in vivo. Albumin secretion was maintained at the same level as that found during the first d in primary culture, and 7-ethoxycoumarin metabolism was maintained over 2 wk in culture at approximately 30% of the levels found in freshly isolated hepatocytes. The improved morphology and function of hepatocyte cultures as spheroids may provide a more appropriate in vitro model for certain applications where the maintenance of liver-specific functions in long-term culture is crucial.  相似文献   

3.
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.  相似文献   

4.
To engineer reliable in vitro liver tissue equivalents expressing differentiated hepatic functions at a high level and over a long period of time, it appears necessary to have liver cells organized into a three‐dimensional (3D) multicellular structure closely resembling in vivo liver cytoarchitecture and promoting both homotypic and heterotypic cell–cell contacts. In addition, such high density 3D hepatocyte cultures should be adequately supplied with nutrients and particularly with oxygen since it is one of the most limiting nutrients in hepatocyte cultures. Here we propose a novel but simple hepatocyte culture system in a microplate‐based format, enabling high density hepatocyte culture as a stable 3D‐multilayer. Multilayered co‐cultures of hepatocytes and 3T3 fibroblasts were engineered on collagen‐conjugated thin polydimethylsiloxane (PDMS) membranes which were assembled on bottomless frames to enable oxygen diffusion through the membrane. To achieve high density multilayered co‐cultures, primary rat hepatocytes were seeded in large excess what was rendered possible due to the removal of oxygen shortage generally encountered in microplate‐based hepatocyte cultures. Hepatocyte/3T3 fibroblasts multilayered co‐cultures were maintained for at least 1 week; the so‐cultured cells were normoxic and sustained differentiated metabolic functions like albumin and urea synthesis at higher levels than hepatocytes monocultures. Such a microplate‐based cell culture system appears suitable for engineering in vitro miniature liver tissues for implantation, bioartificial liver (BAL) development, or chemical/drug screening. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2011.  相似文献   

5.
Cultures of primary hepatocytes from various species, including human, are used in several applications during pre-clinical drug development. Their use is however limited by cell survival and conservation of liver-specific functions in vitro. The differentiation status of hepatocytes in culture strongly depends on medium formulation and the extracellular matrix environment. We incubated primary rat hepatocytes for 10 days on collagen monolayer and in collagen sandwich cultures with or without serum. Restoration of polygonal cell shape and formation of functional bile canaliculi-like structures was stable only in serum-free sandwich cultures. Variations in general cell viability, as judged by the cellular ATP content, LDH release or apoptosis, were less pronounced between alternative cultures. The intracellular glutathione content was preserved close to in vivo levels especially in serum-free sandwich cultures. Basal activities of cytochrome P450 enzymes (P450) varied strongly between cultures. There was a minor effect on CYP1A but CYP2B activity was only detectable in the serum-free sandwich culture after 3 days and beyond. CYP2C activity was slightly elevated in both sandwich cultures, whereas CYP3A showed increased levels in both serum-free cultures. Inducibility of these P450s was fully maintained over time in serum-free collagen sandwich only. Gene expression was largely constant over time in serum-free sandwich cultures that was closest to liver. This liver-like property was supported by protein profiling results. Taken together, the serum-free collagen sandwich culture of primary rat hepatocytes maintained liver-like features over 10 days and is therefore a suitable model for long-term toxicity and drug-drug interaction studies.  相似文献   

6.
Summary A method is described for the attachment to and monolayer culture of adult rat hepatocytes on collagen-coated or fibronectin-coated microbeads or both in a chemically defined serum-free medium. Protein synthesis measured by the incorporation of [3H]leucine into protein was four-fold higher in the hepatocyte microcarrier cultures than in isolated hepatocyte suspensions. The hepatocyte microcarrier cultures showed acute responsiveness to insulin of fatty acid synthesis, glucose incorporation into glycogen, and decarboxylation of [1-14C]pyruvate. Microcarrier-cultured hepatocytes have the combined advantages of monolayer culture and suspension systems. They are a potential tool for the study of long-term as well as acute effects of hormones. This work was supported by the British Diabetic Association.  相似文献   

7.
The elucidation of the effect of extracellular matrices on hepatocellular metabolism is critical to understand the mechanism of functional upregulation. We have developed a system using natural extracellular matrices [Adipogel] for enhanced albumin synthesis of rat hepatocyte cultures for a period of 10 days as compared to collagen sandwich cultures. Primary rat hepatocytes isolated from livers of female Lewis rats recover within 4 days of culture from isolation induced injury while function is stabilized at 7 days post-isolation. Thus, the culture period can be classified into three distinct stages viz. recovery stage [day 0-4], pre-stable stage [day 5-7] and the stable stage [day 8-10]. A Metabolic Flux Analysis of primary rat hepatocytes cultured in Adipogel was performed to identify the key metabolic pathways modulated as compared to collagen sandwich cultures. In the recovery stage [day 4], the collagen-soluble Adipogel cultures shows an increase in TriCarboxylic Acid [TCA] cycle fluxes; in the pre-stable stage [day 7], there is an increase in PPP and TCA cycle fluxes while in the stable stage [day 10], there is a significant increase in TCA cycle, urea cycle fluxes and amino acid uptake rates concomitant with increased albumin synthesis rate as compared to collagen sandwich cultures throughout the culture period. Metabolic analysis of the collagen-soluble Adipogel condition reveals significantly higher transamination reaction fluxes, amino acid uptake and albumin synthesis rates for the stable vs. recovery stages of culture. The identification of metabolic pathways modulated for hepatocyte cultures in presence of Adipogel will be a useful step to develop an optimization algorithm to further improve hepatocyte function for Bioartificial Liver Devices. The development of this framework for upregulating hepatocyte function in Bioartificial Liver Devices will facilitate the utilization of an integrated experimental and computational approach for broader applications of Adipogel in tissue e engineering and regenerative medicine.  相似文献   

8.
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.  相似文献   

9.
Several bioartificial liver devices have been developed as temporary therapy for patients suffering from fulminant hepatic failure. Some of these devices contain porcine hepatocytes entrapped in collagen matrices. In order to improve the function of these BAL devices, there exists a need to optimize metabolic function of cultured hepatocytes. The goal of these investigations was to evaluate the effect of altering culture conditions on rifampin-mediated induction of CYP3A isoforms in cultured porcine hepatocytes. Midazolam metabolism was compared in porcine hepatocytes cultured in a monolayer configuration on collagen gels, in a sandwich configuration between collagen gels and a Matrigel overlay, and in spheroidal cultures. The effect of culture conditions was evaluated, by measuring CYP3A-mediated metabolism of midazolam and by immunoblotting to detect CYP3A proteins, in control cultures and in rifampin-treated cultures. Results obtained by normalizing the metabolism rate data to cell numbers (based on DNA content) present at the end of the culture experiment, showed that there was no difference between the different culture conditions tested. Our results suggest that culturing porcine hepatocytes as spheroids or in a sandwich configuration between collagen and Matrigel, offers no advantage in terms of CYP3A-mediated metabolic function on a per cell basis compared to culturing on collagen gels.  相似文献   

10.
11.
The energy balance in vivo is maintained through inter-organ cross-talk involving several different tissues. As a first step towards recapitulating the metabolic circuitry, hepatocytes, endothelial cells and adipose tissue were connected in a multicompartmental modular bioreactor to reproduce salient aspects of glucose and lipid metabolism in vitro. We first examined how the two-way cellular interplay between adipose tissue and endothelial cells affects glucose and lipid metabolism. The hepatocyte cell line HepG2 was then added to the system, creating a three-way connected culture, to determine whether circulating metabolite concentrations were normalized, or whether metabolic shifts, which may arise when endothelial cells and adipose tissue are placed in connection, were corrected. The addition of hepatocytes to the system prevented the drop in the concentrations of glucose, L-alanine and lactate, and the rise in that of free fatty acids. There was no significant change in glycerol levels in either of the connected cultures. The results show that connected cultures recapitulate complex physiological systemic processes, such as glucose and lipid metabolism, and that the HepG2 hepatocytes normalize circulating metabolites in this in vitro environment in the presence of other cell types.  相似文献   

12.
Hepatocytes are an important research tool used for numerous applications. However, a short life span and a limited capacity to replicate in vitro limit the usefulness of primary hepatocyte cultures. We have hypothesized that in vivo priming of hepatocyte could make them more susceptible to growth factors in the medium for continuous proliferation in vitro. Here, a novel approach used to establish hepatocyte cell lines that included hepatocyte priming in vivo prior to culture with a 3,5-diethoxycarbonyl-1,4-dihydrocollidine diet was attempted. The cell line grew in a monolayer while maintaining a granular cytoplasm and a round nucleus. Electron microscopy displayed hepatocyte-like features including mitochondria, glycogen granules, and the presence of bile canaliculi. This cell line expressed many mature hepatocyte-specific genes including albumin, alpha1-antitrypsin, glucose 6-phosphatase, and tyrosine aminotransferase. Functional characteristic of hepatocytes like the ability to store glycogen, lipid, and synthesis of urea is well demonstrated by this cell line. These cells demonstrated anchorage dependent growth properties in soft agar and did not form tumors after transplantation into nude mice. This cell line can be sustained in culture for more than 100 passages (>1.5 years) without undergoing noticeable morphological changes or transformation. This novel method resulted in the establishment of an immortal, non-transformed hepatocyte cell line with functional characteristics that may aid research of cell metabolism, toxicology, and hepatocyte transplantation.  相似文献   

13.
Summary To develop a strategy for extended primary culture of human hepatocytes, we placed human hepatocytes between two layers of collagen gel, called a “collagen gel sandwich.” Maintenance of hepatocellular functions in this system was compared with that of identical hepatocyte preparations cultured on dry-collagen coated dishes or co-cultured with rat liver epithelial cells. Human hepatocytes in a collagen gel sandwich (five separate cultures) survived for more than 4 wk, with the longest period of culture being 78 d. They maintained polygonal morphology with bile canaliculuslike structures and high levels of albumin secretion throughout the period of culture. In contrast, hepatocytes on dry-collagen became feature-less, and albumin secretion could not be detected after 14 d of culture. This loss of albumin secretion was partially recovered by overlaying one layer of collagen gel. Ethoxyresorufin O-deethylase activity, associated with cytochrome P450 1A2, was detected basally up to 29 d in collagen gel sandwich culture. These activities were induced four- to eightfold after induction with dibenz(a,h)anthracene. Cocultures also maintained basal activity up to 29 d. However, their inducibility was lower than that of hepatocytes in collagen gel sandwich. No ethoxyresorufin O-deethylase activity was detected in hepatocytes cultured on dry-collagen at 7 d. Thus, the collagen gel sandwich system preserves differentiated morphology and functions of human hepatocytes in primary culture for a prolonged period of time. This system is a promising model for studying human hepatocellular function, including protein synthesis and drug metabolism in vitro.  相似文献   

14.
Primary rat hepatocytes formed spheroids in the pores of polyurethane foam (PUF) used as a culture substratum. The hepatocytes in monolayer and spheroid stationary culture converted lidocaine to monoethylglycinexylidide (MEGX) which was N-deethylation of lidocaine. The metabolic activity of the hepatocytes/spheroid stationary culture system was 1.5∼2.0-fold higher than that of monolayer culture for 10 days. The activity of albumin production and cell survival of hepatocytes in monolayer and spheroid cultures decrease due to lidocaine treatment dependend on the lidocaine concentration, but the activity and cell survival in PUF/spheroid stationary culture were maintained at a higher level than that in monolayer culture under the lidocaine treatment. We developed a device for an in vitro liver model, drug metabolism simulator (DMS), using a PUF/spheroid packed-bed module including 4.00 ± 0.68 × 107 hepatocytes and analyzed pharmacokinetics of lidocaine in a one-compartment model. Lidocaine clearance and extraction ratio of hepatocytes in the DMS corresponded to 1.354 ± 0.318 ml/min/g-liver and 0.677 ± 0.0159/g-liver, respectively (N=4). These values were comparable with in vivo values, 1.930 ml/min g-liver and 0.965/g-liver reported by Nyberg (1977). Consequently, PUF/spheroid culture maintained high lidocaine metabolizing activity over a long term and seems to provide a promising culture system as a drug metabolism simulator which will be used for drug screening, cytotoxicity tests and prediction of pharmacokinetics. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

15.
Long-term culture of hepatocytes from human adults   总被引:1,自引:0,他引:1  
A long-term primary human hepatocyte culture retraining liver-specific functions is important and essential for basic research and for the future development of hepatocyte-based applications. We established a normal hepatocyte culture system from excess normal tissues obtained from adult liver cancer patients who received partial liver resection. Hepatocytes were isolated after perfusion and enzymatic disaggregation, and were first maintained in hormonally defined media on a Matrigel matrix, and then transferred to collagen sandwich gel. The hepatocytes formed clusters on the Matrigel matrix and increased in size and numbers with time of culture and eventually grew into spheroids of variable sizes. After being transferred to collagen gel, the cells migrated outward from spheroids to form a monolayer with cuboidal or polygonal cell shapes with granular cytoplasm and continued to proliferate. Cellular functions specific for hepatocytes were analyzed using immunoblot assay for proteins specifically secreted by the liver cells on different days of culture. The cells secreted albumin, transferrin and -fetoprotein consistently for more than 100 days, to a maximum of 150 days. Thus, we have established a long-term culture of hepatocytes from human adults, which will be useful for basic studies of liver physiology such as metabolism and morphogenesis, as well as for other applications in the study of infectious hepatitis, pharmacology, pharmacokinetics, and toxicology.  相似文献   

16.
Cancer drug screening in patient‐derived cells holds great promise for personalized oncology and drug discovery but lacks standardization. Whether cells are cultured as conventional monolayer or advanced, matrix‐dependent organoid cultures influences drug effects and thereby drug selection and clinical success. To precisely compare drug profiles in differently cultured primary cells, we developed DeathPro, an automated microscopy‐based assay to resolve drug‐induced cell death and proliferation inhibition. Using DeathPro, we screened cells from ovarian cancer patients in monolayer or organoid culture with clinically relevant drugs. Drug‐induced growth arrest and efficacy of cytostatic drugs differed between the two culture systems. Interestingly, drug effects in organoids were more diverse and had lower therapeutic potential. Genomic analysis revealed novel links between drug sensitivity and DNA repair deficiency in organoids that were undetectable in monolayers. Thus, our results highlight the dependency of cytostatic drugs and pharmacogenomic associations on culture systems, and guide culture selection for drug tests.  相似文献   

17.
An important application of primary hepatocyte cultures is for hepatotoxicity research. In this paper, gel entrapment culture of rat hepatocytes in miniaturized BAL system were evaluated as a potential in vitro model for hepatotoxicity studies in comparison to monolayer cultures. After exposure for 24 and 48 h to acetaminophen (2.5 mM), gel entrapped hepatocytes were more severely damaged than hepatocyte monolayer detected by methyl thiazolyl tetrazolium (MTT) reduction, intracellular glutathione (GSH) content, reactive oxygen species (ROS) levels, urea genesis and albumin synthesis. CYP 2E1 activities detected by 4-nitrocatechol (4-NC) formation were higher in gel entrapped hepatocytes than in hepatocyte monolayers while the addition of CYP 2E1 inhibitor, diethyl-dithiocarbamate (DDC), more significantly reduced acetaminophen-induced toxicity in gel entrapped hepatocytes. In addition, protective effects of GSH, liquorice extract and glycyrrhizic acid against acetaminophen hepatotoxicity were clearly observed in gel entrapped hepatocytes but not in hepatocyte monolayer at an incubation time of 48 h. Overall, gel entrapped hepatocytes showed higher sensitivities to acetaminophen-induced hepatotoxicity than hepatocyte monolayer by a mechanism that higher CYP 2E1 activities of gel entrapped hepatocytes could induce more severe acetaminophen toxicity. This indicates that gel entrapped hepatocytes in hollow fiber system could be a promising model for toxicological study in vitro.  相似文献   

18.
In vitro drug metabolism by cultured rat, rabbit and human adult hepatocytes has been studied, using ketotifen (ZADITEN) as a model substrate because it is biotransformed in vivo by various metabolic pathways in man and animals. The major in vivo pathways were demonstrated in vitro, namely oxidation in rat hepatocytes, oxidation, glucuronidation and sulfation in rabbit hepatocytes, reduction and glucuronidation in human hepatocytes. Human hepatocytes were the most stable in culture, displaying ketotifen biotransformation for at least one week. These results clearly demonstrated that cultured hepatocytes retain their in vivo specific drug metabolizing activities, including inter-species polymorphism, for a few days. Therefore, pure hepatocyte cultures represent a useful system suitable for drug metabolism studies.  相似文献   

19.
Conventional two‐dimensional cultures in monolayer and sandwich configuration have been used as a model for in vitro drug testing. However, these culture configurations do not present the actual in vivo liver cytoarchitecture for the hepatocytes cultures and thus they may compromise the cells liver‐specific functions and their cuboidal morphology over longer term culture. In this study, we present a three‐dimensional polydimethylsiloxane (PDMS) scaffold with interconnected spherical macropores for the culturing of rat liver cells (hepatocytes). The scaffolds were integrated into our perfusion enhanced bioreactor to improve the nutrients and gas supply for cell cultures. The liver‐specific functions of the cell culture were assessed by their albumin and urea production, and the changes in the cell morphology were tracked by immunofluorescence staining over 9 days of culture period. N‐Acetyl‐Para‐Amino‐Phenol (acetaminophen) was used as drug model to investigate the response of cells to drug in our scaffold‐bioreactor system. Our experimental results revealed that the perfusion enhanced PDMS‐based scaffold system provides a more conducive microenvironment with better cell‐to‐cell contacts among the hepatocytes that maintains the culture specific enzymatic functions and their cuboidal morphology during the culturing period. The numerical simulation results further showed improved oxygen distribution within the culturing chamber with the scaffold providing an additional function of shielding the cell cultures from the potentially detrimental fluid induced shear stresses. In conclusion, this study could serve a crucial role as a platform for future preclinical hepatotoxicity testing. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 30:418–428, 2014  相似文献   

20.
A long-term hepatocyte model in vitro is preferable for chronic hepatotoxicity research because hepatocytes in this model of culture can preserve liver-specific functions for long period. Micro-hollow fiber reactors (MHFR), composed of polysulphone (PS) hollow fibers with a molecular weight cut-off 100 kDa, were applied to test the hepatotoxicity of acetaminophen, isoniazid and rifampicin, respectively. Monolayer culture was used as a control model for hepatocyte culture. It was found that hepatocytes within MHFR were more sensitive to toxicity of acetaminophen (0.38–1.51 g/L) than those in monolayer cultures. Furthermore, significant hepatotoxicity of isoniazid (15 mg/L) and rifampicin (10 mg/L) were detected in hepatocytes cultured in MHFR but not detected in hepatocyte monolayer, which could be due to well-preserved drug metabolizing enzymes in MHFR. These results indicate that the MHFR may be an effective model for long-term hepatotoxicity research in vitro.  相似文献   

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