Nighttime Dim Blue Light Linked to Immune Changes and Stress Hormone Signaling in Mice on a High-Fat Diet

Chronic exposure to nocturnal dim blue light (~5 lx) for 12 weeks is associated with splenic atrophy in high-fat diet-fed mice.

• Splenic immune alterations were observed, including impaired splenocyte proliferation.
• Elevated circulating corticosterone levels were noted alongside increased splenic glucocorticoid receptor expression.
• Increased activation of NF-kB was found, indicating heightened inflammatory signaling.
• Reduced Nrf2/HO-1 signaling and oxidative stress were linked to the exposure.
• Cytokine imbalance in the spleen was also associated with dim blue light exposure.
• Inhibition of corticosterone synthesis or glucocorticoid receptor signaling partially mitigated these immune alterations.

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