An alternative sensing strategy of microglia for pathogen infection: Odorant receptor-pathogen-derived metabolite axis

The goals of this study are to identify ectopic expression of microglial odorant receptors and to demonstrate that microglial odorant receptor have a role in sensing pathogen-derived metabolite for global neuroinflammation. We compared the genetic and functional similarity between S.pneumoniae supernatant-treated and S.pneumoniae-derived metabolite, 2-pentylfuran- treated microglia by analyzing the relationship between DEGs. A significant (p < 0.01) portion of these DEGs, 213 were shared between the DEGs by the supernatant and 2-pentylfuran, including 135 up-regulated and 78 down-regulated genes. To examine cellular processes associated with these shared genes, we performed the enrichment analysis of gene ontology biological processes (GOBPs). These shared up-regulated genes were found mainly associated with the processes related to microglia-mediated neuroinflammation with downstream signaling. Taken together, our study represents the first analysis of primary microglia for identifying ectopic odorant receptors. Our result suggest an alternative sensing strategy of microglia for pathogen infection via odorant receptor-pathogen derived metabolites axis with functional similarity by trascriptome profiling (RNA-seq). Examination of relationship between DEGs in the two comparisons of Sup-treated (n=3) versus control (n=3) microglia (Sup/Ctrl) and 2-PF-treated (n=2) versus control (n=3) microglia (2-PF/Ctrl)