Transcription profiles of mouse microglia isolated by FACS from WT and Grn KO animals, separated by lipofuscin levels [hex001110]

Previous single-cell RNA sequencing of microglia from aged WT and Grn KO mice revealed a microglial subset with transcriptomic signatures that were highly specific to Grn KO. Immunohistochemistry analysis suggested that this population was also characterized by high lipofuscin burden. In this study, we used bulk RNAseq to investigate whether these transcriptomic markers were affected by lipofuscinosis. Microglia were sorted by FACS from dissociated brain tissue of 19-month-old mice of WT or Grn KO background. Cells expressing microglial markers (CD45+/CD11b+) were selected and stratified into lipofuscin ‘low’ or ‘high’ subpopulations, based on autofluorescence. 1,000 cells were collected per sample and were processed and analyzed for bulk RNA sequencing. Results indicated a consistent upregulation of Grn KO-specific genes in microglia from the Grn KO background, which were further enriched ‘high’ vs. ‘low’ lipofuscin cells.