Localization of amyloid P component in human brain: vascular staining patterns and association with Alzheimer's disease lesions.

Abstract

Amyloid P component is a normal serum protein that is highly conserved across phylogeny. Although it resembles the classic acute-phase reactant C-reactive protein, and is considered to be a normal extracellular matrix component, its physiologic role in humans is unknown. Amyloid P component is also colocalized with accumulations of all recognized forms of amyloid. The present study uses light and electron microscopy to compare the cerebral localization of amyloid P component in cases with (n = 19) and without (n = 15) Alzheimer's disease (AD). In non-AD cases, amyloid P component was predominantly localized to the cerebrovasculature. Perivascular staining was observed in most cases, more so in the white than in the gray matter. In AD cases, amyloid P component was localized to all three characteristics histopathologic lesions, namely, neurofibrillary tangles, senile plaques, and amyloid angiopathy. Furthermore, in cases with prominent staining of gray matter parenchymal lesions, intravascular staining was decreased. Given the fixation and processing methods used, amyloid P component was never seen to be localized to the cerebrovascular basement membrane. These data argue against amyloid P component's postulated role as the anchor for vascular beta-amyloid deposition. Because there is no evidence for intrinsic amyloid P component production in brain, its perivascular and parenchymal distributions suggest either compromise of the blood-brain barrier or transport across vascular endothelium.

• Authors: L S Perlmutter, E Barrón, M Myers, D Saperia, H C Chui
• Journal: The Journal of comparative neurology (J Comp Neurol) Vol. 352 Issue 1 Pg. 92-105 (Jan 30 1995) ISSN: 0021-9967 [Print] United States
• PMID: 7714241 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S., Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Serum Amyloid P-Component
• tau Proteins

Topics

• Adult
• Aged
• Aged, 80 and over
• Alzheimer Disease (pathology)
• Blood-Brain Barrier
• Brain (pathology)
• Female
• Humans
• Immunohistochemistry
• Male
• Microglia (ultrastructure)
• Microscopy, Electron
• Middle Aged
• Neurofibrillary Tangles (ultrastructure)
• Serum Amyloid P-Component (ultrastructure)
• tau Proteins (ultrastructure)