In vitro liver tissue model established from transgenic mice: role of HIF-1alpha on hypoxic gene expression.

Publication Type:

Journal Article

Source:

Tissue Eng, Volume 12, Issue 11, p.3135-47 (2006)

Keywords:

Adenoviridae, Animals, Cell Culture Techniques, Cell Hypoxia, Cells, Cultured, Gene Expression Profiling, Gene Expression Regulation, Genome, Glucose Transporter Type 1, Hepatocytes, Hypoxia-Inducible Factor 1, alpha Subunit, Liver, Mice, Mice, Transgenic, Models, Biological, Oligonucleotide Array Sequence Analysis, Polymerase Chain Reaction, Tissue Engineering, Vascular Endothelial Growth Factor A

Abstract:

<p>The instability of the hepatocyte phenotype in vitro has limited the ability to quantitatively investigate regulation of stress responses of the liver. Here, we adopt a tissue-engineering approach to form stable liver tissue in vitro by forming collagen &quot;sandwich&quot; cultures of transgenic murine hepatocytes harboring a regulatory gene of interest flanked by loxP sites. The floxed gene is excised in a subset of cultures by transfection with adenovirus carrying the gene for Cre-recombinase, thereby generating wild-type and null liver tissues from a single animal. In this study, we specifically investigated the role of hypoxia inducible factor 1 alpha (HIF-1alpha) in the hepatocellular response to hypoxia. Using high-density oligonucleotide arrays, we examined genome-wide gene expression after 8 h of hypoxia in wild-type and HIF- 1alpha null hepatocyte cultures. We identified more than 130 genes differentially expressed under hypoxia involved in metabolic adaptation, angiogenic signaling, immediate early response, and cell cycle regulation. Real-time polymerase chain reaction analysis verified that known hypoxia-responsive genes such as glucose transporter-1 and vascular endothelial growth factor were induced in a HIF-1alpha-dependent manner under hypoxia. Our results demonstrate the potential to integrate in vitro tissue models with transgenic and microarray technologies for the study of physiologic stress responses.</p>

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