Abstract TP277: Elovanoids modulate glial phenotypes and provide neuroprotection in experimental ischemic stroke

Objective: Ischemic stroke results in severe loss of neurological function and is a leading cause of death and disability in the world. Administration of a novel class of very long-chain polyunsaturated fatty acids (VLC-PUFAs) derivatives termed elovanoids (ELV34) or their VLC-PUFA precursor (FA34) has shown protective effects after uncompensated oxidative stress and ischemic stress. We found that ELV34 or FA34 delivery attenuates sensorimotor deficits after ischemic stroke. Using a single-cell multiome approach, we found a shift towards disease-associated glial phenotypes following ischemic stroke. Furthermore, ELV and its precursors protect against ischemic damage by restoring the pool of microglia, astrocytes, and oligodendrocytes towards a homeostatic cell-state. Methods: We used 10X Single Cell Multiome (ATAC + Gene Expression) to compare genomic and epigenomic responses in naïve rats and after experimental ischemic treatment. Adult Sprague-Dawley rats underwent 2 hours of middle cerebral artery occlusion (MCAo) via intraluminal suture. Rats received vehicle, ELV34, or FA34 delivered intranasally 1 hour, 1 day, and 2 days after 2 hours of MCAo. A composite neurological score was taken daily, and brains were harvested on day 3. Nuclei were isolated and processed according to the 10X Genomics Single Cell Multiome protocol. Results: ELV34 or FA34 treatment both reduced neurological deficits after MCAo. Joint RNA + ATAC single-cell analysis revealed that ELV34 or FA34 reduced the loss of neuronal populations and reduced infiltrating leukocytes after stroke. Sub-cluster analysis of microglia found that ELV34 and FA34 restored the pool of microglia expressing homeostatic markers (P2ry12, Tmem119, Selplg) while the primary microglia cluster in vehicle expressed disease-associated microglia markers (Spp1, Gpnmb, Cd63). Sub-cluster analysis in astrocytes, oligodendrocytes, and OPC revealed a similar shift in glial profiles towards a homeostatic state after ELV34 and FA34 treatment. Differential gene expression, pathway, and transcription factor motif analysis points to regulation of phagocytic clearance, anti-inflammatory signaling, and neurodegenerative pathways in glial cells after ELV34 or FA34 treatment. Conclusion: ELV34 and its precursor FA34 may exert their bioactivity by modulating conversion to neuroprotective cell phenotypes in ischemic stroke and other neurological diseases.