Myelin injury and degraded myelin vesicles in Alzheimer's disease.
OBJECTIVE
Myelin disruption is an important feature of Alzheimer's disease (AD) that contributes to impairment of neuronal circuitry and cognition. In this study we characterize myelin degradation in the brains of patients with Alzheimer's disease compared with normal aged controls.


METHODS
Myelin from patients with AD (n=13) was compared to matched controls (n=6). Myelin degradation was examined by immunohistochemistry in frontal white matter (WM) for intact myelin basic protein (MBP), degraded MBP, the presence of myelin lipid and for PAS staining. The relationship of myelin degradation and axonal injury was also assessed.


RESULTS
Brains from patients with AD had significant loss of intact MBP, and an increase in degraded MBP in periventricular WM adjacent to a denuded ependymal layer. In regions of myelin degradation, vesicles were identified that stained positive for degraded MBP, myelin lipid, and neurofilament but not for intact MBP. Most vesicles stained for PAS, a corpora amylacea marker. The vesicles were significantly more abundant in the periventricular WM of AD patients compared to controls (44.5 ± 11.0 versus 1.7 ± 1.1, p=0.02).


CONCLUSIONS
In AD patients degraded MBP is associated in part with vesicles particularly in periventricular WM that is adjacent to areas of ependymal injury.
Xinhua
X
Zhan
Glen C
GC
Jickling
Bradley P
BP
Ander
Dazhi
D
Liu
Boryana
B
Stamova
Christopher
C
Cox
Lee-Way
LW
Jin
Charles
C
DeCarli
University of California at Davis, M.I.N.D. Institute - Room 2415, 2805 50th Street, Sacramento, CA 95817, USA. xzhan@ucdavis.edu.
Frank R
FR
Sharp
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000473:pathology*; D001921:Brain / Q000378:metabolism* / Q000473:pathology*; D002552:Cerebral Ventricles / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D004676:Myelin Basic Protein / Q000378:metabolism*; D009186:Myelin Sheath / Q000473:pathology*; D016900:Neurofilament Proteins / Q000378:metabolism
D004676:Myelin Basic Protein; D016900:Neurofilament Proteins