Rev-erbα and retinoic acid receptor-related orphan receptor-α (RORα) are orphan nuclear receptors but their effects on transcription are opposed. Here, we show that Rev-erbα was expressed predominantly in vascular smooth muscle cells (VSMCs) rather than endothelial cells. Overexpression of Rev-erbα upregulated the expression of interleukin-6 and cyclooxygenase-2, and increased transactivation by NF-κB and translocation of p65 to the nucleus in A7r5 VSMCs. Furthermore, the expression of Rev-erbα was upregulated by RORα1 but that upregulation was attenuated by Rev-erbα itself in A7r5 VSMCs. These results suggest a regulatory link between Rev-erbα and the NF-κB pathway.
