Engineering Microglial Cells to Promote Spinal Cord Injury Recovery

Spinal cord injury (SCI) can result in irreversible damage, leading to lifelong paralysis for affected individuals. Microglias dual impact on neuronal regeneration after SCI, driven by their distinct roles at different stages, merits further study. We conducted a bioinformatic analysis of single-cell transcriptomes (scRNA), spatial transcriptomic (ST) data, and bulk RNA-seq data from Gene Expression Omnibus (GEO) datasets. The data were processed using R packages such as "Seurat", "DESeq2","limma" and "GSVA." Additionally, we utilized Gene Set Enrichment Analysis (GSEA) and the Enrichr web servers. Analysis of single-cell data and spatial transcriptomics has revealed notable changes in the microglial cell landscape in SCI. These changes encompass the inhibition of innate microglial cells, while reactive microglial cells exhibit pronounced reactive hyperplasia. Moreover, the TGF{beta} signaling pathway plays a crucial role in regulating the migration of innate microglial cells to enhance SCI recovery. However, reactive microglial cells exhibiting high Trem2 expression contribute to the neuroinflammatory response and can effectively modulate neural cell death in SCI. In particular, inhibiting Trem2 in reactive microglial cells not only reduces inflammation but also mitigates spinal cord injury, and enhancing the TGF{beta} signaling pathway. Whats more, the use of iPSC-derived microglial cells, which have demonstrated their capacity to augment the potential for replacing the functions of naive microglial cells, iPSC-derived microglia have the potential to replace the functions of naive microglial cells, holds significant promise in addressing SCI. Therefore, we posit that the engineering of microglial cells to promote the SCI recovery. The approach of inhibiting Trem2-mediated neuroinflammatory responses and transplanting iPSC-derived microglia with long-term TGF{beta} stimulation may offer potential improvements in SCI recovery.