Alzheimer's disease (AD) is a degenerative brain disease that affects more than 5 million Americans and is the 6th leading cause of death in the United States. There are no known drugs that slow its progression and given its increasing prevalence, the development of new therapeutic options represents an enormous unmet clinical need. The discovery of new therapeutic targets and new drugs that can prevent the neurodegeneration and buildup of neurotoxic protein aggregates, which are the hallmark of AD, are desperately needed. One emerging pathway that has recently garnered attention is autophagy, a highly conserved catabolic pathway that is responsible for the degradation and recycling of cellular components ranging from proteins to whole organelles. There is emerging evidence that autophagic dysfunction is involved in the pathogenesis of AD. Indeed, buildup of autophagic vesicular structures in neurons is also a hallmark in the progression of the disease. It is thought that autophagy is responsible for clearing misfolded protein aggregates, and when it is dysfunctional or can no longer clear the aggregates efficiently enough, neurotoxicty can occur. However, no good drugs exist that increase autophagy to test this hypothesis and serve as potential new drugs. We are proposing to develop small molecules to selectively increase the autophagic rate as a novel therapeutic strategy for slowing the progression of AD. Because protein aggregation is the key phenomenon at the center of AD, we believe that activating the pathway that clears large protein aggregates could provide a novel therapeutic strategy for this disease. There is growing evidence that this pathway is critical for AD. Therefore, we are focusing on the key enzyme that regulates autophagy: ULK1. Upregulation of the ULK1 pathway through rapamycin has been found to improve cognitive ability in AD models. However, rapamycin has many more effects than just autophagy. Therefore, more specific compounds that can specifically target these pathways are needed to test whether autophagy upregulation has therapeutic potential in AD. We have developed a novel high throughput assay for ULK1 that will enable us to screen 400,000 compounds to identify novel activators of autophagy in a target-based screen. We will then perform medicinal chemistry to optimize these compounds for cellular activation of autophagy. The goal of this exploratory grant is to identify novel compounds that activate autophagy as a strategy for treating Alzheimer's disease. In the first aim, we will optimize and then carry out a high-throughput screen to identify novel small molecules that can activate ULK1 activity in vitro, using a novel selective ULK1 assay. In the second aim, we will test the hits in a secondary assay and perform SAR analysis on our compounds, followed by medicinal chemistry lead optimization and structural analysis. Finally, in the third aim, compounds will be tested in cellular assays for autophagy effects and further optimized for ADME properties, selectivity, and potency.
Alzheimer's disease is the 6th leading cause of death in the United States and has no current treatments that can slow its progression. One possible therapeutic target is a process called autophagy, a conserved pathway that helps degrade misfolded proteins. This proposal seeks to find new potential drugs that can activate this pathway, which will make it possible to test this new therapeutic strategy for combatting Alzheimer's disease.
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