Altered expression of synaptic proteins occurs early during progression of Alzheimer's disease.
The expression levels of three synaptic proteins (synaptophysin, synaptotagmin, and growth-associated protein 43 [GAP43]) in AD cases clinically classified by Clinical Dementia Rating (CDR) score were analyzed. Compared with control subjects (CDR = 0), mild (early) AD (CDR = 0.5 to 1) cases had a 25% loss of synaptophysin immunoreactivity. Levels of synaptotagmin and GAP43 were unchanged in mild AD, but cases with CDR of >1 had a progressive decrement in these synaptic proteins. Thus, synaptic injury in frontal cortex is an early event in AD.
Masliah
E
E
Department of Neurosciences, School of Medicine, University of California, San Diego, La Jolla, CA, USA. emasliah@ucsd.edu
Mallory
M
M
Alford
M
M
DeTeresa
R
R
Hansen
L A
LA
McKeel
D W
DW
Morris
J C
JC
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000378:metabolism* / Q000473:pathology; D002135:Calcium-Binding Proteins; D018450:Disease Progression; D005625:Frontal Lobe / Q000737:chemistry / Q000378:metabolism / Q000473:pathology; D019922:GAP-43 Protein / Q000032:analysis / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D008562:Membrane Glycoproteins / Q000032:analysis / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000032:analysis / Q000378:metabolism*; D012720:Severity of Illness Index; D013569:Synapses / Q000737:chemistry / Q000378:metabolism*; D016708:Synaptophysin / Q000737:chemistry / Q000378:metabolism; D050857:Synaptotagmins
D002135:Calcium-Binding Proteins; D019922:GAP-43 Protein; D008562:Membrane Glycoproteins; D009419:Nerve Tissue Proteins; D016708:Synaptophysin; D050857:Synaptotagmins