Elucidating the Role of Glycolytic Metabolism in Dorsal Root Ganglion Development

Neural crest cells (NCCs) are stem cell like population that can generate a wide range of tissues and organs in the vertebrate embryo. As a key NCC derivative, the dorsal root ganglion (DRG) consists of well-organized sensory neurons and satellite glia, playing essential roles in transmitting sensations of touch, pain, itch, temperature, and spatial position. Notably, multiple congenital sensory neuropathies with defective DRG formation are highly associated with metabolic abnormalities, suggesting an active involvement of carbon metabolism during DRG development. However, the specific features and the functions of metabolic regulation in developing DRG remain unclear. Through extensive analysis and validation using chicken, mouse, human DRG organoids and human fetal samples dataset, we previously found that glycolysis is established in a spatiotemporal manner during DRG development, highly conserved across species. We observed that glycolysis is highly active in DRG progenitors and glial-biased lineage and barely detectable in sensory neuronal populations, implying the role of high glycolysis in restraining lineage specification. Inhibition of glycolysis in the DRG, either chemically or genetically, resulted in lineage-biased segregation, leading to an increase in sensory neurons and a decrease satellite glia formation, both in vivo and in vitro. Mechanistically, glycolytic flux could regulate glial-biased gene expressions (e.g., SOX10 gene) by promoting histone acetylation, thereby increasing chromatin accessibility in their promoter and/or enhancer regions. Intriguingly, glycolytic inhibition in glia also disrupted sensory axon outgrowth, suggesting a non-cell autonomous mechanism, likely mediated through metabolic support from satellite glia. Based on these findings, we hypothesize that a delicate glycolytic activity is required in coordinating complex lineage segregation programs during DRG development, which integrates with the existing gene regulatory network via epigenetic regulation. Additionally, glycolysis serves as a bioenergetic process, providing extrinsic metabolites to support nerve fiber outgrowth in developing DRG. In this project, we aim to test our hypothesis through multiple genetic manipulations in chicken and human organoids, with potential inclusion of mouse model if time allows, followed by molecular assays and biosensor, and marker analyses, as well as large-scale omics studies including Single cell-RNA seq, metabolomics and ChIP-seq. We will: (1) Consolidate differential metabolic states during DRG development; (2) Determine the functional importance of glycolysis in regulating DRG development; and (3) Examine how glycolytic metabolism integrates with the gene regulatory network that coordinates DRG development. The Successful implementation of this project will unravel new mechanistic insights into how intracellular metabolism can modulate gene expression to control cell-state transitions for DRG formation. The findings will help in understanding the etiology of sensory neurocristopathies and facilitating energy/metabolic-based therapy for these disorders.