Serum amyloid A in Alzheimer's disease brain is predominantly localized to myelin sheaths and axonal membrane.
Immunohistochemical localization of the injury specific apolipoprotein, acute phase serum amyloid A (A-apoSAA), was compared in brains of patients with neuropathologically confirmed Alzheimer's disease (AD), multiple sclerosis (MS), Parkinson's disease (PD); Pick's disease (Pick's), dementia with Lewy bodies (DLB), coronary artery disease (CAD), and schizophrenia. Affected regions of both AD and MS brains showed intense staining for A-apoSAA in comparison to an unaffected region and non-AD/MS brains. The major site of A-apoSAA staining in both diseases was the myelin sheaths of axons in layers V and VI of affected cortex. A-apoSAA contains a cholesterol binding site near its amino terminus and is likely to have a high affinity for cholesterol-rich myelin. These findings, along with our recent evidence that A-apoSAA can inhibit lipid synthesis in vascular smooth muscle cells suggest that A-apoSAA plays a role in the neuronal loss and white matter damage occurring in AD and MS.
Chung
T F
TF
Department of Biochemistry, Boston University School of Medicine, MA 02118, USA.
Sipe
J D
JD
McKee
A
A
Fine
R E
RE
Schreiber
B M
BM
Liang
J S
JS
Johnson
R J
RJ
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000378:metabolism* / Q000473:pathology; D001053:Apolipoproteins / Q000378:metabolism*; D001921:Brain / Q000378:metabolism* / Q000473:pathology; D002462:Cell Membrane / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D009186:Myelin Sheath / Q000378:metabolism*; D017729:Presynaptic Terminals / Q000378:metabolism*; D011498:Protein Precursors / Q000378:metabolism; D000685:Serum Amyloid A Protein / Q000378:metabolism*
D001053:Apolipoproteins; D011498:Protein Precursors; D000685:Serum Amyloid A Protein