Amyloid-beta deposition in the cerebral cortex in Dementia with Lewy bodies is accompanied by a relative increase in AbetaPP mRNA isoforms containing the Kunitz protease inhibitor.

Deposition of amyloid-beta, the fibrillogenic product of the cell surface protein AbetaPP (amyloid-beta protein precursor), occurs in the cerebral cortex of patients with Dementia with Lewy bodies (DLB). Amyloid deposition, basically in the form of senile plaques, occurs not only in the common form (DLBc), which is defined by changes consistent with diffuse Lewy body disease accompanied by Alzheimer's disease (AD), but also in the pure form (DLBp), in which neurofibrillary tangles are absent. The present study analyses the expression of AbetaPP mRNA isoforms with (AbetaPP751 and AbetaPP770) and without (AbetaPP695) the Kunitz-type serine protease inhibitor (KPI) domain, in the cerebral cortex in DLBc (n=4), DLBp (n=4), Parkinson's disease (PD, n=5), AD (n=3 stages I-IIA, and n=4 stage VC of Braak and Braak), amyloid angiopathy (AA, n=2) and progressive supranuclear palsy (PSP, n=4) compared with age-matched controls (n=6).