Basic Biology IV
The discovery that human skin cells can be reprogrammed into stem cells holds great promise for therapies for degenerative diseases. As many patients in need of regenerative medicine therapies are middle-aged or older, identifying strategies to improve the reprogramming efficiency and quality of cells from aging donors will be crucial in harnessing the full potential of stem cells for therapies. Our idea is that mechanisms that regulate aging, particularly those related to energy metabolism, can be used to enhance stem cell function, particularly when cells come from older individuals. To test this idea, we will analyze the importance of a central energy metabolism gauge in cells termed AMPK in the reprogramming of human skin cells into stem cells. Systematic analysis of metabolic pathways in stem cells and their progeny will give fundamental clues into the mechanisms connecting energy metabolism, aging, and stem cell function. This knowledge will help overcome road-blocks in reprogramming and differentiation into specific lineages, a crucial step in achieving therapeutic tissue replacement. These studies will also increase the pool of drug-targetable molecules that can be used to improve the quality of stem cells for therapies.
Statement of Benefit to California:
Embryonic stem cells hold the promise of treatments and cures for human diseases and conditions that affect millions of people. In particular, neurodegenerative diseases linked with age are affecting increasing number of patients. Thus, one strategy would be to replace degenerating cells in patients with stem cells. However, these approaches will only be possible when the mechanisms controlling the generation of these stem cells and their capacity to produce their functional progeny are better understood in young and old patients. We propose to study the mode of action of metabolism and aging regulators in human cell reprogramming. The AMPK pathway plays major role in metabolism and aging. Metabolic pathways are a major target for the development of therapeutic strategies that may benefit a wide range of patients. However, the mechanisms by which metabolic pathways regulate stem cells are still poorly understood, hampering the development of such strategies. We believe that the results of our experiments will be ultimately translated into novel strategies to cure age-dependent diseases such as neurodegenerative diseases, stroke, diabetes and heart diseases in aging patients.
This project is focused on understanding the relationships between stem cell function and aging, with particular attention to age-related changes in energy metabolism and their effects on cellular reprogramming. The first specific aim is to investigate the role of AMPK, a central regulator of energy metabolism, in human cell reprogramming and properties of induced pluripotent stem cells (iPSCs) from young and aged individuals. The second aim is to identify novel cellular targets that are regulated by AMPK in iPSCs and differentiated progeny cells. The third aim is to compare metabolic profiles of iPSCs and differentiated progeny as a function of age and changes in AMPK pathway activity. Developing a better understanding of the mechanisms that regulate aging may lead to methods to enhance stem cell function. Significance and Innovation - The research addresses an important and little-studied problem: the impact of aging on reprogramming. - Findings from the proposed study could help to overcome major roadblocks in reprogramming and iPSC differentiation and advance progress toward the development of tissues for therapeutic use. - Reviewers found the studies innovative both in their focus on AMPK in iPSCs and in their use of novel approaches for chemical genetics and metabolomics. Feasibility and Experimental Design - Reviewers were impressed by the extensive and compelling preliminary data that support the project’s feasibility. - The overall strategy, methodologies, and analyses were viewed as well reasoned and appropriate to accomplish the goals. - Reviewers criticized the limited discussion of potential problems and alternative approaches. Principal Investigator (PI) and Research Team - The PI is well trained, productive and qualified to oversee the project. - Reviewers praised the extremely strong research team including an outstanding group of co-investigators and collaborators. Responsiveness to the RFA The proposed research is entirely responsive to the RFA with its focus on human stem cells, basic cellular mechanisms and cellular aging.