Mechanisms
CETP activity raises brain cholesterol levels by reducing cholesterol efflux in transgenic mice (J Lipid Res 2022)
Original title: The cholesteryl ester transfer protein (CETP) raises cholesterol levels in the brain
Because wild-type mice lack the CETP-encoding gene and normally have very low LDL levels compared with humans, researchers used CETP transgenic mice fed a high-cholesterol diet to induce CETP expression and studied how this affects the brain. These mice showed up to 22% higher brain cholesterol levels. Microarray analysis of mostly astrocyte-derived mRNA indicated this increase was not due to elevated de novo cholesterol synthesis, but was instead associated with decreased cholesterol efflux alongside upregulation of complement factor C1Q, which normally clears neuronal cholesterol. The findings suggest CETP activity affects brain health by altering cholesterol distribution and clearance, and the authors propose CETP transgenic mice as a valuable tool for studying how cholesterol metabolism influences brain function.
Original abstract
The cholesteryl ester transfer protein (CETP) is a lipid transfer protein responsible for the exchange of cholesteryl esters and triglycerides between lipoproteins. Decreased CETP activity is associated with longevity, cardiovascular health, and maintenance of good cognitive performance. Interestingly, mice lack the CETP-encoding gene and have very low levels of LDL particles compared with humans. Currently, the molecular mechanisms induced because of CETP activity are not clear. To understand how CETP activity affects the brain, we utilized CETP transgenic (CETPtg) mice that show elevated LDL levels upon induction of CETP expression through a high-cholesterol diet. CETPtg mice on a high-cholesterol diet showed up to 22% higher cholesterol levels in the brain. Using a microarray on mostly astrocyte-derived mRNA, we found that this cholesterol increase is likely not because of elevated de novo synthesis of cholesterol. However, cholesterol efflux is decreased in CETPtg mice along with an upregulation of the complement factor C1Q, which plays a role in neuronal cholesterol clearance. Our data suggest that CETP activity affects brain health through modulating cholesterol distribution and clearance. Therefore, we propose that CETPtg mice constitute a valuable research tool to investigate the impact of cholesterol metabolism on brain function.
Summary written by cetpinhibition.org from the published abstract; figures as published. Page updated 19 August 2026. Methods.