SPATA2/CYLD Pathway-Dependent Deubiquitylation of p53 Promotes Ferroptosis in Rat Heart After Ischaemia/Reperfusion Through Suppression of SLC7A11.

BACKGROUND & AIM: Ferroptosis is an iron-dependent cell death and contributes to myocardial ischaemia/reperfusion (I/R) injury. Downregulation of glutathione peroxidase 4 (GPX4) is a key factor to accelerate ferroptosis, but the underlying mechanisms are not fully elucidated. Solute carrier family 7A member 11 (SLC7A11) plays a key role in maintaining the normal level of GPX4, and its transcription is suppressed by p53, whose level is controlled by spermatogenesis-associated protein 2 (SPATA2)/cylindromatosis (CYLD) pathway in a de-ubiquitination-dependent way. This study aims to explore whether SPATA2/CYLD pathway promotes myocardial ferroptosis in rat hearts after I/R through p53-dependent inhibition of SLC7A11.

METHODS

The rat hearts were subjected to 1 h-ischaemia plus 3 h-reperfusion to establish a myocardial I/R injury model, and H9c2 cells were subjected to 8 h-hypoxia plus 12 h-re-oxygenation (H/R) to mimic myocardial I/R injury in vitro.

RESULTS

Both the rat hearts and the cultured cardiomyocytes showed elevated levels of SPATA2 and CYLD, concomitant with the increased p53 levels and the enhanced interaction between SPATA2 and CYLD; these phenomena were reversed by knockdown of SPATA2. Mechanistically, knockdown of SPATA2 restored the ubiquitination of p53 and decreased p53 level in the H/R-treated cardiomyocytes, accompanied by increases in the levels of SLC7A11 and GPX4, and reduction of ferroptosis. Furthermore, suppression of SPATA2 by lurasidone, a predicted inhibitor of SPATA2, in the I/R-treated rat hearts also achieved similar results.

CONCLUSION

SPATA2/CYLD pathway-dependent de-ubiquitylation of p53 promotes ferroptosis in rat heart after I/R through a mechanism involving suppression of SLC7A11.