Acrylic hydrocarbon receptor

Cytosolic and nuclear transcription factor that plays an important role in the regulation of cell growth and cellular differentiation. The receptor binds aromatic hydrocarbons (hence the name), including dioxins and other polychlorinated biphenyls. The resulting receptor-ligand complex binds to DNA in the cell nucleus and activates, among other things, the production of cytochrome P-450.

Ah receptors and UV irradiation of the skin

It could be shown that the Ah receptor plays a central role in the initiation of internal signal cascades after UVB irradiation. In epidermal keratinocytes, UVB irradiation leads to various tryptophan-containing photoproducts. These photoproducts are, besides other aromatic hydrocarbons, natural ligands of the Ah receptor and lead to its activation. In the subsequent signalling cascade, an up-regulation of inflammation-associated genes such as COX-2 occurs, which in turn increases the expression of metalloproteinases such as MMP-1 and MMP-3. Furthermore, melanocyte proliferation and melanin synthesis is initiated. Activation of the Ah receptor continues to play an important role in the development of Treg and gamma-delta T cells; this could have implications for immunological responses.

1. Fritsche E et al (2007) Lightening up the UV response by identification of the arylhydrocarbon receptor as a cytoplasmatic target for ultraviolet B radiation. Proc Natl Acad Sci U S A 104: 8851-8856.
2. Krutmann J et al (2011) Sun exposure: what molecular photodermatology tells us about its good and bad sides. J Invest Dermatol 132: 976-984.
3. Makrantonaki E (2015) Skin aging. Dermatologist 66: 730-737