Item Details

title

A THREE DIMENSIONAL MODEL OF HUMAN HEPATO-BILIARY ORGANOGENESIS

author

Vyas, Dipen

abstract

In recent years, tissue engineering strategies have emerged aimed at generating functional liver tissue by using decellularized liver scaffolds repopulated with liver cells. The quest continues for identifying the best cell source for liver tissue engineering, but one cell source in particular, human fetal liver progenitor cells (hFLPCs), presents the best chance of generating functional liver tissue because of their capability of differentiating into hepatocytes and cholangiocytes. To effectively use these cells for liver tissue engineering, it is critical to understand their developmental biology, ideally in an in vitro system. The goal of this thesis project was to generate a 3D in vitro model of liver tissue using tissue engineering strategies that can recapitulate fetal liver development. There are two key components to our in vitro model: acellular liver scaffold discs that provide 3D native liver tissue microarchitecture and microenvironment, and bipotent hFLPCs obtained from human fetal livers. When seeded with hFLPCs, the ECM discs formed 3D organoids like structure in culture over 3 weeks during the differentiation process. hFLPCs differentiated into both, hepatocytes and cholangiocytes within the organoids and displayed lineage specification and maturation process in a stepwise manner. Hepatocytes displayed transcriptional switch from α-fetoprotein to albumin and isoform switch of fetal cytochrome P450 3A7 to adult cytochrome P450 3A4. Functionally, the organoids displayed albumin and urea secretion along with phase 1 metabolism of diazepam and 7-ethoxy coumarin. The cholangiocytes formed bile duct structures by undergoing biliary morphogenesis process and attained apicobasal polarity in the organoids. The duct morphogenesis process was interrupted by inhibiting Notch signaling, thus creating a liver developmental disease model exhibiting a phenotype similar to Alagille syndrome. Altogether, these results describe, for the first time, a unique 3D in vitro model recapitulating hepato-biliary organogenesis. This model can serve as a tool to study liver development, congenital liver diseases, develop novel therapeutic strategies, drug development and toxicity, and provide information to guide research towards creating functional liver tissue for transplantion.

subject

3D liver tissue

Liver Development

Liver Stem/Progenitor Cells

Liver Tissue Engineering

Organogenesis

contributor

Soker, Shay (committee chair)

Dawson, Paul A (committee member)

Diehl, Anna Mae (committee member)

Almeida-Porada, Graca (committee member)

Shupe, Thomas (committee member)

date

2015-06-23T08:35:58Z (accessioned)

2015 (issued)

degree

Physiology and Pharmacology (discipline)

embargo

forever (terms)

10000-01-01 (liftdate)

identifier

http://hdl.handle.net/10339/57177 (uri)

language

en (iso)

publisher

Wake Forest University

type

Dissertation