NRF2 and microRNAs: new but awaited relations

The nuclear factor erythroid 2-related factor 2 (NRF2) transcription factor is a key player in the cellular antioxidant response and it also controls various other functions in a cell-type specific manner. Due to these key functions, a tight control of NRF2 expression and activity is essential. This regulation is exerted at multiple levels, including transcriptional regulation and proteasomal degradation. Recent studies revealed important roles of miRNAs (miRs) in the control of NRF2 activity through direct targeting of the NRF2 mRNA and of mRNAs encoding proteins that control the level and activity of NRF2. In addition, NRF2 itself has been identified as a regulator of miRs, which exert some of the functions of NRF2 in metabolic regulation and also novel functions in the regulation of cell adhesion. Here, we summarize the roles and mechanisms of action of miRs in the regulation of NRF2 activity and as downstream effectors of this transcription factor.