Elevated plasma cholesterol does not affect brain Abeta in mice lacking the low-density lipoprotein receptor.
Epidemiological studies support an association between vascular risk factors, including hypercholesterolemia, and Alzheimer's disease (AD). Recently, there has been much interest in the possibility that hypercholesterolemia might directly promote beta-amyloid (Abeta) production. Indeed, in vitro studies have shown that increasing cellular cholesterol levels enhances Abeta production. However, studies in AD transgenic mouse models have not consistently found that elevated plasma cholesterol leads to increased Abeta production or deposition in vivo. In this study, we determined whether elevated peripheral cholesterol influences Abeta production in mice with a null mutation of the low-density lipoprotein receptor (LDLR). We show that dramatically elevated plasma cholesterol levels, whether induced by high cholesterol, high fat, or high fat/high cholesterol diets, did not affect either levels of brain Abeta40, Abeta42, or APP, or the Abeta42/40 or APP-CTF/APP ratios, nor substantially alter brain cholesterol levels. ApoE protein levels in brain were, however, elevated, in LDLR-/- mice by post-transcriptional mechanisms. Collectively, these studies argue that plasma cholesterol levels do not normally regulate production of brain Abeta.
Elder
Gregory A
GA
Department of Psychiatry, Mount Sinai School of Medicine, New York, NY 10029, USA.
Cho
Julie Y
JY
English
Daniel F
DF
Franciosi
Sonia
S
Schmeidler
James
J
Sosa
Miguel A Gama
MA
Gasperi
Rita De
RD
Fisher
Edward A
EA
Mathews
Paul M
PM
Haroutunian
Vahram
V
Buxbaum
Joseph D
JD
D016229:Amyloid beta-Peptides / Q000378:metabolism*; D000704:Analysis of Variance; D000818:Animals; D001057:Apolipoproteins E / Q000235:genetics / Q000378:metabolism; D001921:Brain / Q000378:metabolism*; D002784:Cholesterol / Q000097:blood*; D015870:Gene Expression / Q000235:genetics; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010446:Peptide Fragments / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D011973:Receptors, LDL / Q000172:deficiency*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D016229:Amyloid beta-Peptides; D001057:Apolipoproteins E; D010446:Peptide Fragments; D012333:RNA, Messenger; D011973:Receptors, LDL; C078592:amyloid beta-protein (1-40); C075222:amyloid beta-protein (1-42); D002784:Cholesterol