Human and zebrafish mineralocorticoid receptors reporter cell assays to assess the activity of chemicals

The action of environmental chemicals (ECs) on the mineralocorticoid receptor (MR) has been suggested to impair physiological processes regulated by this nuclear receptor. However, it remains understudied both as a target of ECs and with respect to potential species-specific differences. In this regard, we have developed reporter cell lines to identify the response to different steroids, ECs, and urban wastewater (WW) sample extracts of human MR (hMR) and zebrafish MR (zfMR). Most of the steroids had a higher efficacy on zfMR than hMR, while the ECs were antagonists to both hMR and zfMR, with a lower potency on the latter. Interestingly, WW sample extracts revealed the presence of MR activity with a greater activity on zfMR compared to hMR, suggesting the presence of steroids in WW. These screening tools have proven to be powerful tools for characterizing the interaction of chemicals with MRs and revealing their presence in environmental samples.