Friday, December 1, 2023
12/1/2023
Abstract Arriving at a more granular understanding of the molecular drivers of appetite will represent a major step towards the ultimate goal of more efficiently treating obesity. AgRP neurons in the arcuate nucleus (ARC) of the hypothalamus play a dominant role in maintaining energy balance and are dysregulated in obesity. We have recently utilized cutting-edge tools to enable an unprecedented cell type-specific characterization of the transcriptional and epigenomic landscape of AgRP neurons, and this information was leveraged to identify one transcription factor, Interferon Regulatory Factor 3 (IRF3) that mediates the acute anorectic effects of leptin. The current project seeks to examine the role of AgRP neuron IRF3 (IRF3AgRP) in the development of diet- induced obesity (DIO) involving loss- and gain-of-function experiments while assessing the impact on mouse body weight, feeding behavior, and leptin sensitivity. The transcriptomic profiles of these IRF3 functional mouse models will be examined in the lean state in response to leptin, and in the obese state. Additionally, the direct DNA binding targets of IRF3AgRP will be elucidated using a cutting-edge, low-input, alternative to ChIP- seq called CUT&RUN, all in the lean fed, fasted, and leptin treated state, and in response to obesity. AgRP neuron-specific ATAC-seq for lean and obese AgRP neuronal nuclei will also be performed as a means of assessing the transcriptional regulatory status of IRF3 and other TFs during obesity. Finally, using both lean and obese mice that are either wild-type or have IRF3 knockout out of all leptin-receptor expressing cells, I will perform single nucleus RNA-seq as a means of identifying the IRF3-driven transcriptional programs onboard in the obese state. Overall, these studies will test the overarching hypothesis that IRF3 plays key roles in mediating both acute leptin sensitivity as well as the development of diet-induced obesity owed to chronic IRF3 activation via hyperleptinemia. The regulatory pathways highlighted in this project will point to novel therapeutic targets for the treatment of obesity, a major risk factor for type 2 diabetes. During the course of the mentored phase of this application, I will further strengthen the computational skills needed to analyze RNA-seq, ATAC- seq, CUT&RUN, and single-nucleus RNA-seq datasets independently. I will also engage in various career development experiences, while also receiving invaluable mentorship from my career advisory committee. In all, the funding of the proposed project will ensure that I round out my scientific and professional training while laying the foundation for a viable independent academic research program.
HHS’ Tracking Accountability in Government Grants System (TAGGS) website provides access to detailed descriptions of grants, loans, aggregated direct payments and other types of financial assistance awarded by the HHS Operating Divisions (OPDIVs) and the Office of the Secretary Staff Divisions (STAFFDIVs).
