Dataset Information

A comparative study of genome-wide transcriptional profiles of primary hepatocytes in collagen sandwich and monolayer cultures.

ABSTRACT: Two commonly used culture systems in hepatic tissue engineering are the collagen sandwich (CS) and monolayers of cells. In this study, genome-wide gene expression profiles of primary hepatocytes were measured over an 8-day period for each cell culture system using Affymetrix GeneChips and compared via gene set enrichment analysis to elicit biologically meaningful information at the level of gene sets. Our results demonstrate that gene expression in hepatocytes in CS cultures steadily and comprehensively diverges from that in monolayer cultures. Gene sets up-regulated in CS cultures include several associated with liver metabolic and synthesis functions, such as metabolism of lipids, amino acids, carbohydrates, and alcohol, and synthesis of bile acids. Monooxygenases such as Cytochrome-P450 enzymes do not show any change between the culture systems after 1 day, but exhibit significant up-regulation in CS cultures after 3 days in comparison to hepatocyte monolayers. These data provide insights into the up- and down-regulation of several liver-critical gene sets and their subsequent effects on liver-specific functions. These results provide a baseline for further explorations into the systems biology of engineered liver mimics.

SUBMITTER: Kim Y

PROVIDER: S-EPMC2988646 | biostudies-literature | 2010 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

A comparative study of genome-wide transcriptional profiles of primary hepatocytes in collagen sandwich and monolayer cultures.

Kim Yeonhee Y Lasher Christopher D CD Milford Logan M LM Murali T M TM Rajagopalan Padmavathy P

Tissue engineering. Part C, Methods 20100607 6

Two commonly used culture systems in hepatic tissue engineering are the collagen sandwich (CS) and monolayers of cells. In this study, genome-wide gene expression profiles of primary hepatocytes were measured over an 8-day period for each cell culture system using Affymetrix GeneChips and compared via gene set enrichment analysis to elicit biologically meaningful information at the level of gene sets. Our results demonstrate that gene expression in hepatocytes in CS cultures steadily and compreh ...[more]

PMID: 20412007

Similar Datasets

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

Project description:We have used primary monolayer cultures of rat hepatocytes to study the effects of physiological concentrations of various bile acids, commonly found in bile of normal rats, on the mechanism of regulation of cholesterol 7 alpha-hydroxylase and bile acid synthesis. Addition of taurocholic acid, the most predominant bile acid in rat bile, to the culture medium suppressed cholesterol 7 alpha-hydroxylase activity and mRNA time- and dose-dependently. The decrease in enzyme activity paralleled the changes in mRNA. Maximal suppression of cholesterol 7 alpha-hydroxylase mRNA (-91%) and enzyme activity (-89%) was observed after a 16 h incubation period with 50 microM taurocholic acid. The declines in mRNA and enzyme caused by taurocholic acid were tightly coupled and followed first-order kinetics with a half-life of 4 h. Transcriptional activity, as assessed with nuclear run-on assays, was decreased by 44% at 50 microM taurocholic acid. Mass production of bile acids (chenodeoxycholic acid and beta-muricholic acid) was inhibited to a similar extent as the cholesterol 7 alpha-hydroxylase when different concentrations of taurocholic acid were used, giving maximal inhibition (-81%) at 50 microM taurocholic acid. Glycocholic acid and unconjugated cholic acid were equally effective as taurocholic acid in suppressing cholesterol 7 alpha-hydroxylase mRNA. The more hydrophobic bile acids (chenodeoxycholic acid and deoxycholic acid) showed profound suppression of the cholesterol 7 alpha-hydroxylase mRNA by 85% and 75% respectively, whereas the other trihydroxy bile acids in rat bile, alpha- and beta-muricholic acid, were not or only marginally active. We conclude that rat bile acids, in particular the more hydrophobic ones, in concentrations commonly observed in portal blood, exert negative feedback control at the level of cholesterol 7 alpha-hydroxylase mRNA in cultured rat hepatocytes through a direct effect on the hepatocytes, and that down-regulation of transcription is only one of the mechanisms involved in this regulation.

Project description:The liver is one of most important organs in our bodies. It performs many essential functions including metabolism, synthesis, secretion, detoxification, and storage. Hepatocytes are the principal cell type in the liver and are involved in multiple liver-specific functions. There have been several efforts to develop in vitro culture systems capable of maintaining hepatocyte-specific phenotype over long time periods. In hepatic tissue engineering, two commonly used culture systems are the collagen sandwich and monolayers of cells. ‚àö√á¬¨‚Ä†In this study, genome-wide gene expression profiles of primary hepatocytes were measured over an 8-day period for each cell culture system using Affymetrix GeneChips and analyzed via Gene Set Enrichment Analysis (GSEA), which is a powerful method to elicit biologically meaningful information from microarray data at the level of gene sets. Results indicate that the gene expression in hepatocytes in collagen sandwich cultures gradually diverges from that in monolayer cultures. Gene sets up-regulated in collagen sandwich cultures include those associated with liver metabolic and synthetic functions. ‚àö√á¬¨‚Ä†These functions are associated with lipid, amino acid, carbohydrate, and alcohol metabolism and bile acid synthesis. Nuclear receptors are up-regulated in collagen sandwiches 24 hours after seeding. Signals transmitted from these receptors may cause the up-regulation of other processes in subsequent days. Cytochrome-P450 monooxygenase expression was initially down-regulated but exhibited up-regulation after 72 hours. Our results provide a baseline for further explorations into the systems biology of engineered liver mimics as well as 2D and 3D co-cultures of primary hepatocytes and non-parenchymal cells. To better understand differences in quality of in vitro growth of rat hepatocytes between culture on a monolayer of collagen gel and sandwiched between two layers of gel, we measured gene expression in hepatocytes in these two culture conditions in triplicate for four time points: 1 day, 2 days, 3 days, and 8 days of culturing. Overall, we obtained Affymetrix microarray data for 24 samples, divided to 12 samples from monolayer and double layer cultures each, each of which are divided into four time points with 3 sample replicates.

Dataset Information

A comparative study of genome-wide transcriptional profiles of primary hepatocytes in collagen sandwich and monolayer cultures.

Publications

A comparative study of genome-wide transcriptional profiles of primary hepatocytes in collagen sandwich and monolayer cultures.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets