Molecular mechanism of NR4A1/MDM2/P53 signaling pathway regulation inducing ferroptosis in renal tubular epithelial cells involved in the progression of renal ischemia-reperfusion injury.

Revealing the possible molecular mechanism of the NR4A1 (nuclear receptor subfamily 4 group A member 1)-MDM2 (MDM2 proto-oncogene)-P53 (tumor protein p53) signaling pathway that induces ferroptosis in renal tubular epithelial cells. Renal ischemia-reperfusion injury (RIRI) -related datasets were obtained from the GEO database. Differentially expressed genes in RIRI were analyzed using R language, intersected with RIRI-related genes in the GeneCard database, and retrieved from the literature to finally obtain differential ferroptosis-related genes. An in vitro cell model of RIRI was constructed using mouse renal cortical proximal tubule epithelial cells (mRTEC cells) treated with hypoxia-reoxygenation (H/R). Bioinformatic analysis showed that NR4A1 may be involved in RIRI through the induction of ferroptosis; in addition, we predicted through online databases that the downstream target gene of NR4A1, MDM2, could be targeted and regulated by ChIP and dual luciferase assays, and that NR4A1 could prevent MDM2 by inhibiting it, and NR4A1 was able to promote ferroptosis by inhibiting the ubiquitinated degradation of P53. NR4A1 expression was significantly increased in mRTEC cells in the hypoxia/reoxygenation model, and the expression of ferroptosis-related genes was increased in vitro experiments. NR4A1 reduces the ubiquitinated degradation of P53 by targeting the inhibition of MDM2 expression, thereby inducing ferroptosis and ultimately exacerbating RIRI by affecting the oxidative respiration process in mitochondria and producing oxidized lipids. This study presents a novel therapeutic approach for the clinical treatment of renal ischemia-reperfusion injury by developing drugs that inhibit NR4A1 to alleviate kidney damage caused by renal ischemia-reperfusion.