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Liver organoid co-cultures: bidirectional interactions between ductal cells and semenchyme

Liver organoid co-cultures: bidirectional interactions between ductal cells and semenchyme

By In Aiv Internship On April 8, 2019

Internship title: Liver organoid co-cultures: bidirectional interactions between ductal cells and semenchyme

Name: Huch lab. Stem cell and tissue regeneration in liver and pancreas
Affiliation: Gurdon Institute
Address: Tennis Court Road, CB2 1QN
E-mail: mh771@cam.ac.uk

LAB Director
Name: Meritxell Huch
Phone number: 0044 1223334130
E-mail: mh771@cam.ac.uk

Name: Meritxell Huch
Phone number: 00441223334130
E-mail: mh771@cam.ac.uk

Subject Keywords: co-culture, organoids, mesenchymal, endothelial, liver
Tools and methodologies: Organoid culture.
Image analysis
FACS analysis
Summary of lab’s interests: The Huch lab is interested in understanding the molecular and cellular mechanisms of tissue regeneration. We study the liver, as a model organ with high regenerative capacity. For that we use both mouse models and mouse and human organoid models we have developed over the past years. We mainly focus on the epigenetic mechanisms and cellular effectors that drive liver regeneration.
Project summary: Liver epithelial cells –hepatocytes and bile duct cells– intermingle with a microenvironment of endothelial cells, macrophages and mesenchymal cells to form the functional unit of the tissue. In chronic or severe liver injury, when hepatocyte proliferation is compromised, ductal cells become activated into bipotential progenitors to replace lost epithelium. This process can be recapitulated in vitro by growing hepatic ductal cells under defined extracellular matrix and growth factors, which generates 3D epithelial ‘liver organoids’ that resemble adult tissue, yet lack stromal cell components (Huch et al., 2013). In this dissertation, we compared the capacity of two broad hepatic stromal cell populations, hematopoietic/endothelial (H/E) and mesenchymal (Msc) cells, to behave as a nurturing ‘niche’ of the ductal epithelium. In the absence of exogenous growth factors, primary Msc but not H/E cells support ductal cell proliferation and organoid formation in vitro. In vivo, mesenchymal cells localise periportally, closely surrounding biliary duct cells, and co-expanding with them during damage-induced regeneration. Isolated mesenchymal cells support liver organoid formation independently of cell-to-cell contact. Mesenchyme-sustained organoids resemble those grown in standard medium. Liver organoids can in turn support the expansion of Msc cells in vitro, suggesting a positive feedback loop of growth. However, physical contact fromMsc cells can be cytostatic for the ductal cells depending on the ratio between the two cell populations. Interestingly, the mesenchymal-to-ductal ratios that permit and inhibit ductal proliferation in vitro recapitulate the ratios observed between the two populations in vivo, during the different phases of liver regeneration. Our findings underscore how the relationship between the ductal epithelium and its mesenchymal microenvironment regulate tissue regeneration.
Interdisciplinary aspect of the project: The student benefited from performing co-cultures and FACS sorting analysis and image analysis from immunofluorescent images.