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

Vibriani A, Chen X, Kajiwara S, Orihara K

J Mol Med (Berl) 2026

The increased reliance on digital devices in our daily lives has exposed humans to intense levels of high-energy blue light. However, the harmful effects of blue light irradiation on human skin are less understood than UV irradiation. Notably, we demonstrated that blue light induces skin photoaging through a novel mechanism involving disruption of the circadian rhythm. An in vitro study using human keratinocyte cells and dermal fibroblasts was conducted. The results showed that blue light irradiation triggers cellular senescence and downregulates key aging-associated markers, including extracellular matrix components, epithelial barrier protein, NAD

6 Figures Extracted

Fig. 1 PMC

Experimental timeline of the in vitro study. Cells were serum-starved for 24 h prior to cellular clock reset with 100 nM dexamethasone. Following 2 h ...

Fig. 2 PMC

SA-β-gal activity upon blue light irradiation. Microscopic image showing SA-β-gal activity of dermal fibroblasts in control ( A ) and 1-h blue light i...

Fig. 3 PMC

The circadian profile of BMAL1 and PER3 gene expression in dermal fibroblasts. The circadian rhythm graph ( A , E ), MESOR ( B , F ), amplitude ...

Fig. 4 PMC

Analysis of clock-related genes, extracellular matrix genes, and NAD + metabolism genes in dermal fibroblasts. The circadian rhythm graph ( A – F ) o...

Fig. 5 PMC

The circadian profile of BMAL1 and PER3 in HaCaT cells. The circadian rhythm graph ( A , E ), MESOR ( B , F ), amplitude ( C , G ), and trough/peak...

Fig. 6 PMC

Analysis of clock-related genes, tight junction genes, and NAD + metabolism genes in HaCaT cells. The circadian rhythm graph ( A, E, F, G ) of TJP1,...