Light Exposure, Physical Activity, and Indigeneity Modulate Seasonal Variation in NR1D1 (REV-ERBα) Expression

We found that the morning nuclear receptor subfamily 1 group D member 1 (NR1D1 or REV-ERBα) expression in the human mononuclear cells of Arctic residents has a seasonal rhythm, with its peak at the summer solstice and nadir at the winter solstice. Actigraphy data indicated that the expression of REV-ERBα was significantly associated with physical activity and natural daylight exposure, suggesting a responsiveness to external cues. We also found that indigenous populations have elevated REV-ERBα expression compared to non-indigenous populations, particularly at the summer solstice. These results highlight the dynamic regulation of REV-ERBα and its sensitivity to both environmental and genetic influences. These findings suggest the potential roles of REV-ERBα in seasonal adaptation and/or metabolic differences among human populations and encourage further exploration of these findings, which may shed light on the complex interplay between environmental cues, genetic backgrounds, and REV-ERBα-mediated human physiological processes.