A Mechanistic Foundation for the Iron Homeostasis Impacts and Neurotrophic Activity of trans-Banglene

Project Summary/Abstract Neurodegenerative diseases, including Alzheimer’s, Parkinson’s, and Huntington’s disease, constitute one of the greatest challenges in modern therapeutic development due to an inadequate understanding of the interplay of pro- and anti-apoptotic feedback mechanisms operative in the progression of these diseases. This

inadequate understanding is in part due to a lack of practical (crosses blood-brain-barrier, well-studied mechanism of action) biochemical tools to modulate and effect related cellular processes, such as neurotrophic responses (pro-survival, pro-growth, and pro-differentation responses), and metal ion homeostasis levels,

which are both significantly perturbed in neurodegenerative contexts. The Williams lab and Epp lab propose to evaluate the mechanism and pathological impacts of a non-peptide small molecule, called trans-banglene (t-BG), which has demonstrated neurotrophic effects in cell culture, primary neurons and mouse models of neurodegeneration, is orally bioavailable, and also has recently been

shown by the Williams lab to alter iron-binding proteins in PC 12 cells. This combined impact on neurotrophic responses and iron homeostasis makes t-BG well suited to provide insight into the interplay between these two cellular response mechanisms. However, a cellular target and mechanism of action is not yet known for t-BG.

The following proposal outlines work to 1) identify the cell recognition/binding partner and localization upon binding, 2) characterize t-BG treatment impacts on known neurotrophic signal transduction pathways, iron localization, and lipid oxidation profile in cells and tissues and 3) to evaluate impacts on neuronal morphology,

plasticity and neurogenesis in AD mouse models. The interdisciplinary setting of the Williams lab enables both synthetic access to derivatives of this molecular scaffold as well as cell response data from biochemical assays of their activity. The Epp lab will concurrently validate mechanistic impacts in hAPOE4 knock-in mouse tissues

and measure changes in neurogenesis/neuron structure. Importantly, these mechanistic studies will improve understanding of the differential drivers of neurotrophic effects and iron homeostasis. Once mechanism of action is determined, and validated in mouse models, this orally bioavailable molecular tool can be broadly employed in the biomedical community to study inhibition of

neurodegenerative disease progression, helping to create the foundation for new medicinal strategies. Further, once a cellular target is established, future work will use structural information regarding binding mode to inform optimization studies that increase potency and drug-like characteristics for t-BG, improving its utility and

facilitating drug development investigations.