Continuous Light Does Not Affect Atherosclerosis in APOE*3-Leiden.CETP Mice

Area of Science:

• Cardiovascular Science
• Metabolic Research
• Chronobiology

Background:

• Artificial light at night is linked to dyslipidemia, a risk factor for atherosclerotic cardiovascular disease.
• The impact of artificial light at night on atherosclerosis progression is not well understood.

Purpose of the Study:

• To investigate whether constant bright light exposure exacerbates atherosclerosis in a mouse model with human-like lipid metabolism.

Main Methods:

• Female APOE*3-Leiden.CETP mice were exposed to either a regular light-dark cycle or constant bright light for 14 weeks.
• Evaluated food intake, body weight, body composition, metabolic organ weights, plasma lipid levels, and atherosclerotic lesion size.
• Assessed immune cell counts and performed behavioral analysis to examine circadian rhythm disruption.

Main Results:

• Constant light exposure led to a minor reduction in food intake but did not affect body weight or composition.
• Non-high-density lipoprotein (HDL) cholesterol levels increased under constant light, but atherosclerotic lesion size and severity remained unchanged.
• Mice under constant light showed reduced immune cell counts and variable behavioral responses to light, with blunted or extended activity rhythms.

Conclusions:

• Constant bright light does not promote atherosclerosis in APOE*3-Leiden.CETP mice, possibly due to reduced immune cell counts.
• The potential contribution of artificial light exposure to human cardiovascular disease risk requires further investigation.