Towards the development of a liver in vitro system that recapitulates Wnt-driven zonation

Valle-Encinas, Eider 2020. Towards the development of a liver in vitro system that recapitulates Wnt-driven zonation. PhD Thesis, Cardiff University. Item availability restricted.

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Abstract

A local Wnt niche sustained by the hepatic central vein shape the transcriptional program of pericentral hepatocytes. The Wnt pathway additionally orchestrates liver regeneration following injury. In the recent years, protocols for the growth of two types of hepatic organoids (bile duct(BD)-derived and primary hepatocyte (PH)-derived organoids) have been developed. However, these in vitro systems do not capture aspects of metabolic zonation in a continuous and thereby fail to fully replicate the organ biology. In this thesis, I aimed to make significant advances in the development of a zonated liver in vitro system by developing the molecular tools to recreate the Wnt microenvironment of the hepatic central vein in vitro and assessing the cellular responses of the current hepatic organoid systems to Wnt activation. Using covalently immobilized Wnt and Rspo ligands, the local presentation of Rspo3 and addition of soluble Wnt9b was found an attractive strategy to recreate the central vein microenvironment in vitro. Activation of the Wnt pathway in PH organoids resulted in an increased expression of Wnt-driven metabolic pericentral genes. By contrast, activation of the Wnt pathway in BD organoids resulted in an enhanced expression of hepatocyte progenitor cell markers rather than pericentral metabolic genes. Using bile BD organoids in combination with different genetic mouse models, we uncovered a potential role for the Wnt pathway in BEC plasticity. Together, this study suggests that PH organoids but not BD organoids mirror the behaviour of homeostatic hepatocytes and thereby may serve as cellular platform to recapitulate the biology of the resting liver. The adaptation and controlled presentation of biological and physicochemical cues in hepatocyte culture systems may help us to better understand the mechanisms that govern zonation and develop therapies for pathological conditions where zonation is perturbed.

Item Type:	Thesis (PhD)
Date Type:	Completion
Status:	Unpublished
Schools:	Biosciences
Subjects:	Q Science > Q Science (General)
Date of First Compliant Deposit:	3 December 2020
Last Modified:	27 Jul 2023 10:22
URI:	https://orca.cardiff.ac.uk/id/eprint/136780

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