Time-resolved single-cell RNAseq profiling identifies a novel Fabp5+ subpopulation of inflammatory myeloid cells with delayed cytotoxic profile in chronic spinal cord injury

Traumatic spinal cord injuries (SCI) are a group of highly debilitating pathologies affecting thousands annually, and adversely quality life. Currently, no fully restorative therapies exist, SCI still results in significant personal, societal financial burdens. Inflammation plays major role the evolution SCI, with myeloid cells, including bone marrow derived macrophages (BMDMs) microglia (MG) being primary drivers both early secondary pathogenesis delayed wound healing events.The precise cell subsets is unclear as upon crossing blood-spinal barrier, infiltrating may take on morphology resident microglia, upregulate canonical markers, thus making two populations difficult to distinguish.Here, we used time-resolved scRNAseq transgenic fate-mapping chart transcriptional profiles tissue-resident -infiltrating cells mouse model thoracic contusion SCI.Our work identifies novel subpopulation foam cell-like inflammatory increased expression Fatty Acid Binding Protein 5 (Fabp5) comprise cells. Fabp5+ display cytotoxic profile that predominant at lesion epicentre extends into chronic phase SCI.