Analysis of prion protein aggregates in blood and brain from pre-clinical and clinical BSE cases.

Prion diseases are infectious neurodegenerative diseases affecting humans and animals. The food-borne bovine spongiform encephalopathy (BSE) had serious impact on both economy and public health, respectively. To follow the pathogenesis of BSE, oral challenge studies were previously conducted, among others on the Isle of Riems, Germany (Balkema-Buschmann et al., 2011b). In the present work brain and plasma samples from this pathogenesis study were subjected to surface fluorescence distribution analysis (sFIDA). sFIDA is a diagnostic tool that exploits the aggregated state of the disease-related prion protein (PrP) as a biomarker for prion disorders. With the exception of one animal, all tested brain samples from clinical cattle exhibited a high titer of PrP particles. Moreover we could detect PrP aggregates already 16 and 24 months after infection. In contrast to our previous demonstration of PrP particles in blood plasma from scrapie sheep, however, no aggregates could be identified in plasma from pre-clinical and clinical cattle. This is in accordance with other studies suggesting a restriction of the BSE infection to the central nervous system.

Detection of α-synuclein aggregates by fluorescence microscopy.

Parkinson disease (PD) is one of the most common age-related neurodegenerative diseases associated with motor deficiencies in humans. The symptoms are caused by the death of dopaminergic neurons in the brain, which is accompanied by the misfolding and aggregation of the protein α-synuclein. Diagnosis is based on the incidence of clinical symptoms, although they only appear as a result of the irreversible damage of neurons during the disease. Identification of a suitable biomarker would allow preclinical diagnosis. We an approach to quantify single α-synuclein aggregates as a possible biomarker for PD.