Harnessing cell-mediated matrix remodelling by human iPSC-derived intestinal organoids within 3D materials to understand epithelial-mesenchymal intera

PhD project: aims and description
The human intestine can be modelled in vitro using organoids cultured within Matrigel, a
tumour-derived 3D matrix. However, Matrigel's physical properties, such as its stiffness and
degradability cannot be tuned, which limits our ability to understand how the matrix and
matrix remodeling impacts the intestinal epithelium (and vice versa). The Gentleman Lab has
recently discovered that stem cells encapsulated within hydrogels with defined physical
properties remodel their surroundings by secreting matrix proteins locally and by degrading
their surrounding environment, which impacts their fate (Ferreira, Nat Commun 2018).
Here, we will exploit this discovery by melding the Gentleman Lab's (KCL) expertise in
synthetic 3D matrices with the Stagg's (QMUL) interests in gut inflammation and the Neves
Lab's (KCL) organoid-based models of the intestine to develop human organoid-based models
of IBD within defined, synthetic, modifiable 3D environments, which we will use to ask
fundamental questions in how the matrix impacts the epithelium (and vice versa) in health
and disease. To accomplish this, we will create human induced pluripotent stem cell (iPSC)-
derived intestinal organoids (hIO) and encapsulate them within PEG-based synthetic
hydrogels in which we can independently modulate stiffness, ligand density and
degradability. Using knockdown/overexpression approaches, microrheology techniques, and
hydrogels with controlled softening/stiffening, we will then mechanistically probe how a
combination of cell-mediated matrix secretion/degradation and/or altered local mechanical
properties impact organoid phenotype. This will allow us to identify potential matrix targets
within the intestinal wall that could be exploited therapeutically.
Specific Aims:
1. Establish and characterize a human iPSC-derived organoid-based model of IBD by
modulating synthetic hydrogels' physical properties.
2. Understand the impact on epithelial and mesenchymal cells of modulating local matrix
remodelling around organoids using knockdown and overexpression techniques.
3. Understand how modulating local matrix mechanical properties around organoids impacts
epithelial and mesenchymal cells.