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

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