NEURONAL ACTIVITY- AND CONTEXT-DEPENDENT SELECTIVE VULNERABILITY OF NEURONAL SUBPOPULATIONS FOR PANOPTOSIS PROGRAMS

Upon direct cell-neuron contact, Th17 cells release glutamate, which can lead to excitotoxic neuronal cell death, although specific neuronal pathways involved in this context are unclear. Therefore, we here focus on dissecting neuron subtype- and context-specific response programs in an inflammatory environment. We utilized the RiboTag method, which enables time-resolved and cell type specific insights on neuronal signaling spanning conditions from homeostasis to inflammatory mouse models. Using this method we performed a translatomic sequencing analysis of excitatory, inhibitory and active neurons using CamKII, Gad2 and cFos specific promotors in vivo. Early and chronic neuroinflammation was induced by experimental autoimmune encephalomyelitis (EAE), the murine model of multiple sclerosis. cFos TRAP (Targeted Recombination in Active Populations) mice and cell type deconvolution with BRETIGEA allowed time and stimulus dependent analysis of bulk gene expression in activated neurons. Using DESeq2 and GSEA (Gene Set Enrichment Analysis) we investigated gene regulation and upregulated KEGG pathways depending on EAE and compared them across timepoints. Temporal expression of cFos and GCaMP6f was characterized in murine primary neurons using immunohistochemistry. Our results revealed a context and cell type specific response to early neuroinflammation via the RIPK1/3 axis leading to panoptosis. Th17-cell associated signaling pathways indicate interactions with the Cytosolic DNA-sensing pathway during inflammation. cFos-positive neurons demonstrated distinct translatomic signatures compared to excitatory and inhibitory neurons. Concluding, cFos-positive neurons tend to be a highly vulnerable subset during neuroinflammation. Due to the RiboTag method we detected broad neuronal pathway plasticity. This dataset might link activity-dependent and inflammatory-induced transcriptional programs.