Whole blood gene expression profiling in preclinical and clinical cattle infected with atypical bovine spongiform encephalopathy.

The molecular events at the basis of prion diseases are characterized by the involvement of several genes which are differentially regulated during the onset and the progression of the infection. Gene expression profiling studies are a powerful tool for the development of preclinical diagnostic tests. Most of the studies performed up to date utilized tissues which are not suitable for a future perspective of a rapid analysis of the infected animals and patients. We used microarrays to identify the differentially regulated transcripts in blood of BSE-infected cattle in both the presymtomatic and the symptomatic stage of the infection. The identified genes may be used as a signature for prion diseases. Cattle were intracranially inoculated with atypical BSE (H- or L- type) and the blood sampling was achived prior and after the onset of the symptoms. Not inoculated cattle were used as control. RNA was isolated from blood and processed for the hybridization on Affymetrix microarray chips.