From the ArcaMax Publishing, Technology Videos Newsletter:
http://www.arcamax.com/news/techvideo/s-641422-190923
SEATTLE (UPI) -- A U.S. medical researcher says he has determined two
commonly used statins have different drug and cell dependent effects
in the brain.
Professor John Albers and colleagues at the University of Washington's
Northwest Lipid Metabolism and Diabetes Research Laboratories at the
University of Washington compared the effects of two statins --
simvastatin (Zocor) and pravastatin (Pravachol) on two different types
of brain cells -- neurons and astrocytes, which are support cells that
help repair damage.
The scientists said although statins are of great value in treating
high cholesterol and lowering the risk of heart disease, studies
suggest similar statin drugs can have profoundly different effects on
brain cells -- both beneficial and detrimental.
By directly applying the drugs to cells as opposed to administering
them to animals, the scientists said they could eliminate differences
in the drugs' ability to cross the blood-brain barrier as a reason for
any differing effects.
Albers and his team said they looked at the expression of genes
related to neurodegeneration, and found, despite using biologically
equivalent drug concentrations, differences between both cells and
drugs.
For example, the scientists said simvastatin reduced the expression of
the cholesterol transporter ABCA1 by approximately 80 percent in
astrocytes while pravastatin lowered expression by only around 50
percent. Another difference was that while both statins decreased
expression of the Tau protein -- associated with Alzheimer's disease
-- in astrocytes, they increased Tau expression in neurons.
Pravastatin also increased the expression of another Alzheimer's
hallmark, amyloid precursor protein.
While increased levels of these two proteins may account for potential
risks of disease, Albers said large decreases in cholesterol proteins
like ABCA1 should be considered. Brain cholesterol levels tend to be
reduced in elderly people, and in such individuals the long-term
effects of statin therapy could lead to transient or permanent
cognitive impairment.
The researchers said their findings reinforce the idea that great care
should be taken in deciding the dosage and type of statin given to
individuals, particularly elderly people.
The study is reported in The Journal of Lipid Research.