Affiliations: Roberts Laboratory for Neurodegenerative Disease Research, Sun Health Research Institute, Sun City, AZ, USA
Correspondence:
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Address for correspondence: D. Larry Sparks, Sun Health Research Institute, 10515 W. Santa Fe Drive, Sun City, AZ 85351, USA. E-mail: Larry.Sparks@sunhealth.org.
Abstract: Pioneering autopsy studies revealed a possible link between coronary artery disease, cholesterol and Alzheimer's disease (AD). In the cholesterol-fed rabbit model of human coronary artery disease, we identified numerous neuropathologic features of AD including central accumulation of amyloid-β (Aβ) and cognitive deficits compared to rabbits fed unaltered diet. Removing cholesterol from the diet or treatment with cholesterol-lowering medications reversed the severity of AD-like alterations. This fostered the rationale for testing a cholesterol-lowering statin medication for benefit in the treatment of AD. Further studies suggested that the cholesterol-fed rabbit was a viable model for AD, but the severity of the neuropathology produced exhibited gender-related differences. Furthermore the induction of AD-like neuropathology by dietary cholesterol was found to depend on the quality of water the animal was drinking. Cholesterol-fed rabbits drinking distilled water showed minimal central changes, whereas animals drinking distilled water supplemented with low levels of copper were severely affected. It was clear that cholesterol caused the over-production of Aβ in the brain and copper influenced its clearance to the blood. Emerging data suggest that low-density lipoprotein receptor-related protein-1 (LRP) on brain capillaries clears Aβ from brain and that excess circulating copper negatively influences this process.
