|Knowles, Donald - Don|
Submitted to: Journal of Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/28/2009
Publication Date: 6/10/2009
Publication URL: http://ddr.nal.usda.gov/dspace/bitstream/10113/33110/1/IND44257350.pdf
Citation: Stanton, J.B., Knowles Jr, D.P., Call, D.R., Mathison, B.A., Baszler, T.V. 2009. Limited transcriptional response of ovine microglia to prion accumulation. Journal of Virology. Available: doi:10.1016/j.bbrc.2009.06.030 Interpretive Summary: This research utilized microarray-based analysis (probing for gene expression) to test for which genes are induced to express due to infection of microglial cells (brain macrophages from sheep) with scrapie. The results showed that compared to gene expression responses of microglial cells to infection with viruses and bacteria, the induced changes in gene expression due to infection with the biochemically abnormal prions involved in scrapie are less. Analysis revealed 19 up-regulated genes and 30 down regulated genes in microglial cells infected with scrapie associated prion. This work moves forward our understanding of changes in cell gene expression patterns in response to scrapie associated prion infection.
Technical Abstract: Sheep scrapie (Sc) is the classical transmissible spongiform encephalopathy (prion disease). The conversion of normal cellular prion protein (PrPC) to disease-associated prion protein (PrPSc) is the fundamental pathogenesis of prion diseases. Many of the molecular mechanisms contributing to prion diseases are not fully understood, nor is it clear how cell biology is impacted by this process. To further characterize the molecular changes associated with PrPSc accumulation, primary sheep microglia were infected with PrPSc and then the transcriptional profile of these PrPSc-accumulating microglial cells was compared to the profile of PrPSc-lacking microglial cells using the Affymetrix bovine genome array. The experimental design included three biological replicates, each with three technical replicates, and samples that were collected when ELISA results indicated maximal PrPSc-accumulation. The array analysis revealed 19 upregulated genes and 30 downregulated genes in PrPSc accumulating microglia. Three transcripts (CCL2, SGK1, and AASDHPPT) were differentially regulated in a direction similar to previous reports from mouse or human models, whereas three other transcripts (MT1E, NR4A1, PKP2) responded oppositely from previous reports. Overall, the results demonstrated a limited transcriptional response to PrPSc accumulation, as compared with microglia and macrophages that are infected with other infectious agents such as viruses and bacteria. This is the first microarray-based analysis of prion accumulation in primary cells derived from a natural TSE-host.