Year 3

The goal of this project was to test how metabolism impacts human induced pluripotent stem cells (iPSCs). A key metabolic-sensing protein is called AMP-dependent protein kinase (AMPK): it has been called the “energy gauge” of cells. During the past years, we showed that the metabolism-sensing AMPK is highly expressed in human iPSCs and that it becomes activated upon nutrient deprivation. There are humans harboring mutations in their AMPK gene, and these mutations lead to diseases, notably major brain and heart malfunctions. Using genome-engineering, we were able to model these human mutations in AMPK in human iPSCs. This is important because it allows to model the “disease in a dish” and to determine the cellular and molecular causes for these disorders. Finally, we were able to find novel substrates of AMPK in human cells (some of them are also substrates in iPSCs). Collectively, our results show that metabolism pathways are highly regulated in human stem cells and could play critical role for the quality and derivation of these cells into cardiac cells or neurons. Our other goal was to use a more global, unbiased approaches and pioneer novel technology to analyze the metabolism of human stem cells with the goal to improve their generation and derivation into cardiac or neuronal cells. We have now optimized cutting-edge technology that can identified a series of lipid metabolites, which was not possible before. As AMPK activation (and low energy in general) leads to lipid utilization by cells, probing lipid metabolism is critical in improving stem cell function and quality. Out work should provide new knowledge on the metabolism of stem cells and improve the generation and derivation of human iPSCs into specialized cells for personalized regenerative medicine.