APP processing and b-amyloid deposition in sporadic Creutzfeldt-Jakob patients is dependent on Dab1.

Alzheimer"s disease and prion pathologies (e.g., Creutzfeldt-Jakob disease (CJD)) display profound neural lesions associated with aberrant protein processing and extracellular amyloid deposits. Dab1 has been implicated in the regulation of Amyloid Precursor Protein (APP), but a direct link between human prion diseases and Dab1/APP interactions has not been published. Here we examined this putative relationship in seventeen cases of sporadic CJD (sCJD) post mortem. Biochemical analyses of brain tissue revealed two groups, which also correlated with PrPsc types 1 and 2. One group, with PrPsc type 1 showed increased Dab1 phosphorylation, and lower CTF production with an absence of A deposition. The second sCJD group, which carried PrPsc type 2, showed lower levels of Dab1 phosphorylation and CTF production, and A deposition. Thus, the present observations suggest a correlation between Dab1-phosphorylation, A deposition and PrPsc type in sCJD.