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

Abstract

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 "sandwich" 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.

• Authors: Jared W Allen, Salman R Khetani, Randall S Johnson, Sangeeta N Bhatia
• Journal: Tissue engineering (Tissue Eng) Vol. 12 Issue 11 Pg. 3135-47 (Nov 2006) ISSN: 1076-3279 [Print] United States
• PMID: 17518628 (Publication Type: Journal Article)

Chemical References

• Glucose Transporter Type 1
• Hif1a protein, mouse
• Hypoxia-Inducible Factor 1, alpha Subunit
• Vascular Endothelial Growth Factor A

Topics

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