Skin chromophores and photobiological signaling pathways

Skin chromophores are endogenous molecules, such as DNA, melanin, urocanic acid, and porphyrins, that absorb specific wavelengths of light to initiate biological responses. In keratinocytes, DNA damage from UV absorption triggers the p53 pathway, leading to the release of alpha-melanocyte-stimulating hormone (alpha-MSH). This hormone binds to the melanocortin 1 receptor (MC1R) on melanocytes to stimulate eumelanin production, providing photoprotection (D'Orazio et al., 2013). Additionally, chromophores like trans-urocanic acid undergo photoisomerization to cis-urocanic acid, which modulates T cell activity and contributes to systemic immunosuppression (Gibbs et al., 2008). While these pathways are essential for protection against radiation, their dysregulation or overexposure to UV leads to skin cancers, photoaging, and inflammatory conditions. Therapeutic interventions often involve exogenous chromophores in photodynamic therapy or protective filters in sunscreens to modulate these interactions.

Other names

Cellular and tissue chromophores in skin leading to downstream pathways in melanocytes, keratinocytes, and T cellsCutaneous chromophoresSkin light-absorbing moleculesPhotobiological signaling system