Cholesterol in the senile plaque: often mentioned, never seen.
The lipid components of the senile plaque (SP) remain largely unknown. Senile plaques were said to be enriched in cholesterol in a few studies using the cholesterol probe filipin and a histoenzymatic method based upon cholesterol oxidase activity. We provide data that strongly suggest that these results are false-positive: the SPs were still stained in the absence of the enzyme cholesterol oxidase; filipin still labeled the plaques after lipid extraction. On the other hand, resorufin, the highly fluorescent end-product of the histoenzymatic method, bound with high affinity to the SPs and neurofibrillary tangles in a cholesterol-independent manner, and might serve as a new marker of amyloid. In conclusion, the probable cholesterol enrichment of the SPs has never been proven so far, and might necessitate non-histological methods to be ascertained.
Lebouvier
Thibaud
T
Escourolle Neuropathology Laboratory, La Salpêtrière Hospital, Assistance Publique, Hôpitaux de Paris and UPMC, Paris Universitas, Paris, France.
Perruchini
Claire
C
Panchal
Maï
M
Potier
Marie-Claude
MC
Duyckaerts
Charles
C
D000544:Alzheimer Disease / Q000378:metabolism / Q000473:pathology; D001921:Brain / Q000378:metabolism* / Q000473:pathology; D002540:Cerebral Cortex / Q000378:metabolism / Q000473:pathology; D002784:Cholesterol / Q000737:chemistry / Q000378:metabolism*; D002789:Cholesterol Oxidase / Q000378:metabolism; D005372:Filipin / Q000737:chemistry; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D008856:Microscopy, Fluorescence; D058225:Plaque, Amyloid / Q000378:metabolism* / Q000473:pathology; D013702:Temporal Lobe / Q000378:metabolism / Q000473:pathology
D005372:Filipin; D002784:Cholesterol; D006861:Hydrogen Peroxide; D002789:Cholesterol Oxidase