Time-dependent transcriptomic response to scrapie exposure in ovine MSC-derived neuron-like cells.

Prion diseases are fatal neurodegenerative disorders in which early molecular responses to prion exposure remain incompletely understood, particularly in naturally susceptible hosts. In the present study, we performed RNA-sequencing analysis of ovine mesenchymal stem cell-derived neuron-like cells exposed to classical scrapie brain homogenate and compared their transcriptomic response with that of cells exposed to normal brain homogenate. Cells were analyzed at 2 and 4 days post-inoculation (dpi). Differential expression analysis identified 76 genes at 2 dpi and 124 genes at 4 dpi, with limited overlap between time points, indicating a dynamic response to scrapie exposure. At 2 dpi, enriched biological processes among upregulated genes were mainly related to signaling- and immune-associated transcriptional responses, whereas downregulated genes were enriched in developmental, morphogenetic and lipid-related processes. At 4 dpi, the transcriptional profile was dominated by broader gene repression and showed reduced functional specificity. RT-qPCR analysis of eight selected genes supported the direction of change detected by RNA-seq in most cases. Overall, these results indicate that scrapie exposure elicits a time-dependent transcriptional response in ovine MSC-derived neuron-like cells and provide an exploratory framework for studying early molecular responses associated with prion exposure in a naturally susceptible species.