Impact of acute blue light irradiation on the molecular clock and markers associated with photoaging in skin cell models

-dependent metabolic stress sensor (SIRT1), and aging-sensitive NAD + producer (NAMPT). Remarkably, we found that blue light irradiation disrupted the circadian rhythm at the cellular level. This is evidenced by phase-shifted PER3 mRNA levels, loss of BMAL1 protein rhythmicity, and altered temporal expression of aging-associated markers. Our results demonstrate that blue light triggers skin photoaging through circadian disruption, establishing a novel mechanistic pathway that transforms our understanding of photoaging complexity. This study initiates the framework for developing chronotherapy-based interventions to address the growing epidemic of digital device-associated skin damage and, therefore, could be used as a scientific foundation for developing novel active compounds in cosmeceutical products. KEY MESSAGES: We identified novel mechanisms in blue light-induced skin photoaging. Acute blue light exposure induced cellular senescence in skin cells. Acute blue light exposure downregulated key aging-associated markers in skin cells. Acute blue light exposure disrupted the circadian rhythm of skin cells. Targeting circadian rhythm offers a promising therapeutic route for skin photoaging.