Spatial Environment Affects HNF4A Mutation-Specific Proteome Signatures and Cellular Morphology in hiPSC-Derived β-Like Cells

Studies of monogenic diabetes are particularly useful as we can gain insight into the molecular events of pancreatic β-cell failure. Maturity-onset diabetes of the young 1 (MODY1) is a monogenic diabetes form, caused by a mutation in the HNF4A gene. Human induced pluripotent stem cells (hiPSC) provide an excellent tool for disease modelling by subsequent directed differentiation toward desired pancreatic islet cells, but cellular phenotypes in terminally differentiated cells are notoriously difficult to detect. Re-creating a spatial (3D) environment may facilitate phenotype detection. In this study, we studied MODY1 using hiPSC-derived pancreatic β-like patient and isogenic control cell lines in two different 3D contexts. Using size-adjusted cell aggregates and alginate capsules we showed that the 3D context was critical to facilitate the detection of mutation-specific phenotypes. In 3D cell aggregates we identified irregular cell clusters and lower levels of structural proteins by proteome analysis, whereas in 3D alginate capsules we identified altered levels of glycolytic proteins in the glucose sensing apparatus by proteome analysis. Our study provides novel knowledge on normal and abnormal function of HNF4A paving the way for translational studies of new drug targets that can be used in precision diabetes medicine of MODY.