Estrogen receptor and aryl hydrocarbon receptor signaling pathways

Estrogen receptor and aryl hydrocarbon receptor signaling pathways

Estrogen receptors (ERs) and the aryl hydrocarbon receptor (AhR) are ligand activated transcription factors and members of the nuclear receptor and bHLH-PAS superfamilies, respectively. AhR is involved in xenobiotic metabolism and in mediating the toxic effects of dioxin-like compounds. Crosstalk has been observed among AhR and nuclear receptors, but has been most well studied with respect to E...

Interactions between aryl hydrocarbon receptor (AhR) and hypoxia signaling pathways.

Most if not all of the toxic responses of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) are mediated through the AhR, which requires ARNT to regulate gene expression. ARNT is also required by HIF-1alpha to enhance the expression of various genes in response to hypoxia. Since both the AhR and hypoxia transcriptional pathways require ARNT, some of the effects of TCDD and similar types of ligands cou...

Red Clover Aryl Hydrocarbon Receptor (AhR) and Estrogen Receptor (ER) Agonists Enhance Genotoxic Estrogen Metabolism

Many women consider botanical dietary supplements (BDSs) as safe alternatives to hormone therapy for menopausal symptoms. However, the effect of BDSs on breast cancer risk is largely unknown. In the estrogen chemical carcinogenesis pathway, P450 1B1 metabolizes estrogens to 4-hydroxylated catechols, which are oxidized to genotoxic quinones that initiate and promote breast cancer. In contrast, P...

Aryl Hydrocarbon Receptor Activation

Aryl Hydrocarbon Receptor Repressor and TiPARP (ARTD14) Use Similar, but also Distinct Mechanisms to Repress Aryl Hydrocarbon Receptor Signaling

The aryl hydrocarbon receptor (AHR) regulates the toxic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The AHR repressor (AHRR) is an AHR target gene and functions as a ligand-induced repressor of AHR; however, its mechanism of inhibition is controversial. Recently, we reported that TCDD-inducible poly (ADP-ribose) polymerase (TiPARP; ARTD14) also acts as a repressor of AHR, representin...