GADD45α is a direct target of TFEB and contributes to tacrolimus-induced chronic nephrotoxicity

Tacrolimus-induced chronic nephrotoxicity (TICN) hinders its long-term use, but its mechanism remains unclear. Tacrolimus exerts its pharmacological effect by inhibiting calcineurin and its substrate NFAT. Whether the inhibition of other calcineurin substrates is related to TICN remains to be explored. Transcription factor EB (TFEB), a substrate of calcineurin, plays a crucial role in various homeostasis. Herein, we found that tacrolimus inhibited TFEB nuclear translocation and activity in mouse kidneys and HK-2 cells. Then, TFEB gain- and loss-of-function rescued the effect of tacrolimus in HK-2 cells. Furthermore, TFEB activation both by phosphorylation sites mutation and agonist rescued TICN in mice. To elucidate the mechanism of TFEB, we analyzed ChIP-seq data. Growth arrest and DNA damage-inducible 45α (GADD45α) was identified as a transcriptional target of TFEB via chromatin immunoprecipitation and dual luciferase reporter assays. And then we revealed that GADD45α overexpression rescued DNA damage and kidney injury caused by tacrolimus or TFEB knockdown in vitro, and vise versa. The protective effect of GADD45α against TICN and DNA damage was further demonstrated by overexpressing it in mice. In conclusion, the persistent inhibition of TFEB-GADD45α pathway by tacrolimus contributes to TICN. This study identifies a specific target for intervention of TICN.