This research project focuses on stress-response pathways and their role in the aging process. More specifically, it concentrates on the hypoxia-inducible factor-1, (HIF-1), a highly conserved transcription factor involved in response to low oxygen. Recent reports have placed HIF-1 at the core of a newly discovered age- related pathway in the nematode Caenorhabditis elegans. Interestingly, knocking out the HIF-1 repressor vhl-1 significantly increases lifespan in worms, but causes a disease (von Hippel Lindau disease) in humans. My research focuses on how HIF-1 stabilization positively affects longevity in worms, studying the associated tissues and downstream factors necessary for lifespan effects and separating them from those that cause disease in people. Since stress response pathways like HIF-1 are highly conserved, it is likely that at least some of the downstream effectors in worms will be present in mammals. In characterizing these downstream genes, I will use biochemical techniques including a novel approach to measure covalent changes made to HIF-1. The development of this approach will answer questions about how HIF-1 is regulated and provide a blueprint for similar studies in HIF-1 and other stress-response proteins in worms and other organisms. At the conclusion of the described experiments, I will show that HIF-1 stabilization in a known set of cells can increase worm healthspan and longevity by activating specific proteins in specific cells. I will characterize the function of thse proteins and whether they lie downstream of any other aging interventions. In doing this, I will develop a protocol to measure HIF-1 post-translational modifications in response to a known transcriptional repressor, and plan to expand these experiments in future studies. Thus, these studies will be important for defining the role of stress response pathways in longevity. This transitional award will encompass the final two years of my postdoctoral research and the first three years of my independent, faculty training. During the mentored stage of the proposal, I will define the tissues and learn the techniques to characterize the downstream proteins necessary for HIF-1-mediated longevity, including developing the methodology for measuring its post-translational modifications. After transitioning to independence, I will more fully characterize th HIF-1 signaling pathway and its downstream proteins with a focus on eventually transitioning the work into mammalian models. As a transitional award, this proposal also focuses on many aspects of career development. Both the mentored and independent portions of the proposal emphasize training in the classroom and in the laboratory while continuing to write and review papers and grant applications. In summary, this project will help define how the hypoxic response pathway could improve healthspan and lifespan in mammals while also providing opportunities for training during the mentored stage, separating and distinguishing my work from that of my mentor, and developing a new experimental protocol.
The research described in this proposal will demonstrate how a protein called the hypoxia-inducible factor-1 (HIF-1), that can cause a disease in humans, is able to increase lifespan in the roundworm Caenorhabditis elegans. By finding the mechanism and important tissues responsible for longevity, we will differentiate the good, longevity inducing effects from the bad, disease causing effects of this protein. The end result will suggest how the HIF-1 pathway can be utilized to increase lifespan and healthspan in people.
| Leiser, Scott F; Jafari, Gholamali; Primitivo, Melissa et al. (2016) Age-associated vulval integrity is an important marker of nematode healthspan. Age (Dordr) 38:419-431 |
| Leiser, Scott F; Rossner, Ryan; Kaeberlein, Matt (2016) New insights into cell non-autonomous mechanisms of the C. elegans hypoxic response. Worm 5:e1176823 |
| Leiser, Scott F; Miller, Hillary; Rossner, Ryan et al. (2015) Cell nonautonomous activation of flavin-containing monooxygenase promotes longevity and health span. Science 350:1375-1378 |
