title: Amyloid precursor protein expression is enhanced in human platelets from subjects with Alzheimer's disease and frontotemporal lobar degeneration: a real-time PCR study.
abstract: Frontotemporal lobar degeneration (FTLD) and Alzheimer's disease (AD) represent the most frequent causes of early-onset and late-onset degenerative dementia, respectively. A correct diagnosis entails the choice of appropriate therapies. In this view the present study aimed to identify biomarkers that could improve the differential diagnosis. We recently found an overexpression of platelet amyloid precursor protein (APP) in AD; furthermore, recent studies have suggested the presence of changes in APP processing in FTLD. In this context, we analyzed the mRNA expression level of Total APP (TOT) and APP containing a Kunitz-type serine protease inhibitor domain (KPI) in platelets obtained from AD patients, subjects with FTLD, and healthy subjects. In addition, we evaluated the correlation between platelet APP mRNA expression levels and cognitive impairment.Differential gene expression measurements revealed a significant up-regulation of APP TOT and APP KPI in both AD and FTLD patients compared to the controls (being AD/Controls: 1.67 for APP TOT and 1.47 for APP KPI; FTLD/Controls: 1.62 for APP TOT and 1.51 for APP KPI; p < 0.05), although it is interesting to note that in FTLD patients this expression did not correlate with the severity of cognitive impairment.This could be related to a reduced beta-amyloid (Aβ) formation, caused by an alteration of secretase enzymatic activity, even though a post-transcriptional regulation of APP mRNAs in FTLD cannot be excluded.
authors.forename: Arianna
authors.initials: A
authors.lastname: Vignini
authors.forename: Stefano
authors.initials: S
authors.lastname: Morganti
authors.forename: Eleonora
authors.initials: E
authors.lastname: Salvolini
authors.forename: Davide
authors.initials: D
authors.lastname: Sartini
authors.forename: Simona
authors.initials: S
authors.lastname: Luzzi
authors.forename: Rosamaria
authors.initials: R
authors.lastname: Fiorini
authors.forename: Leandro
authors.initials: L
authors.lastname: Provinciali
authors.forename: Roberto
authors.initials: R
authors.lastname: Di Primio
authors.forename: Laura
authors.initials: L
authors.lastname: Mazzanti
authors.forename: Monica
authors.initials: M
authors.lastname: Emanuelli
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000097:blood / Q000175:diagnosis* / Q000235:genetics / Q000523:psychology; D016564:Amyloid beta-Protein Precursor / Q000097:blood* / Q000235:genetics; D001792:Blood Platelets / Q000378:metabolism*; D016022:Case-Control Studies; D003071:Cognition; D003937:Diagnosis, Differential; D005260:Female; D057174:Frontotemporal Lobar Degeneration / Q000097:blood / Q000175:diagnosis* / Q000235:genetics / Q000523:psychology; D005819:Genetic Markers; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D012333:RNA, Messenger / Q000097:blood; D060888:Real-Time Polymerase Chain Reaction; D012720:Severity of Illness Index; D015854:Up-Regulation
chemical_list: C545487:APP protein, human; D016564:Amyloid beta-Protein Precursor; D005819:Genetic Markers; D012333:RNA, Messenger