Dietary Interventions to Limit Heterotopic Ossification after Musculoskeletal Injury - Project Summary Heterotopic ossification (HO) is a debilitating condition characterized by aberrant bone formation in soft tissues following trauma or surgery, often leading to chronic pain, severe functional impairment, and reduced quality of life. Notably, obesity increases the risk of developing HO, complicating recovery outcomes. Current treatment options for HO are limited or invasive, underscoring the urgent need for innovative, non-invasive strategies to prevent HO onset and progression. Recent studies suggest that dietary interventions, specifically calorie restriction (CR) and intermittent fasting (IF), may hold therapeutic potential by modulating inflammation and promoting tissue regeneration in other disease contexts. However, no dietary interventions currently exist to prevent or reverse HO. This proposal aims to investigate dietary therapies, specifically CR and IF, as potential interventions to target the key inflammatory and cellular pathways central to HO. The central hypothesis guiding this research is that dietary modifications regulate HO formation and progression through CCL2-mediated monocyte recruitment, with the timing of these modifications being crucial to their therapeutic efficacy. Aim 1 will define the optimal therapeutic window for CR and IF, examining pre-injury and post-injury regimens to establish the timing and duration of the diet that maximally suppresses HO formation in clinically relevant mouse models of trauma and surgery. High resolution micro-computed tomography (µCT), histology, and functional assessments will be used to evaluate treatment efficacy. Aim 2 will delineate the mechanistic effects of CR and high-fat diet on mesenchymal progenitor cell (MPC)-monocyte interactions, focusing on the CCL2-CCR2 signaling axis. Lineage specific and global gene deletion mice with impaired CCL2-CCR2 signaling will be used to investigate how dietary modifications impact monocyte recruitment, inflammation, and HO progression. Advanced molecular techniques, including single-cell RNA sequencing (scRNA-seq), spatial transcriptomics, and multiplexed ion beam imaging (MIBI), will be employed to evaluate how dietary interventions affect inflammatory signaling and immune cell dynamics in HO. This research addresses a critical public health challenge by aiming to develop novel, non-invasive dietary strategies that could prevent HO and transform recovery and long-term outcomes for high-risk patients, particularly those with obesity. The applicant will conduct this work under the mentorship of clinician scientist Dr. Benjamin Levi at UT Southwestern Medical Center, who is a previous F32 recipient and who has mentored several F32 awardees who now run independent laboratories. The training plan that includes advanced coursework and hands-on experience in scRNA-seq and spatial transcriptomics, high-resolution imaging, immunology, bioinformatics, and metabolomic techniques, preparing the applicant for a career as a physician-scientist specializing in tissue regeneration and wound healing.
