Targeting prominin-2/BACH1/GLS pathway to inhibit oxidative stress-induced ferroptosis of bone mesenchymal stem cells.

Suppressing bone mesenchymal stem cell (BMSC) ferroptosis is expected to optimize BMSCs-based therapy for intervertebral disc degeneration (IVDD). Our previous study revealed that Prominin-2 could protect against ferroptosis by decreasing cellular Fe2+ content and inhibiting transcription regulator protein BACH1 (BACH1) expression. In this study we probed the molecular mechanisms underlying the Prominin-2/BACH1 pathway in BMSC ferroptosis. Using an array of in vitro and in vivo experiments we found that heat shock factor protein 1 (HSF1) activates PROM2 (encoding protein Prominin-2) transcription and elevated Prominin-2 expression. Furthermore, we showed that Prominin-2 attenuates ferroptosis induced by tert-butyl hydroperoxide (TBHP) through promoting BACH1 ubiquitination and degradation. Inhibition of BACH1 expression reversed TBHP-stimulated down expression of glutaminase kidney isoform, mitochondrial (GLS), which plays a crucial role in protecting BMSCs against ferroptosis. Targeting the Prominin-2/BACH1 axis has also been shown to improve BMSC survival post-transplantation and mitigate IVDD progression by inhibiting ferroptosis. Our results support a new mechanistic insight into the regulation of the Prominin-2/BACH1/GLS pathway in BMSC ferroptosis. These finding could lead to potential therapeutic targets to improve the survival of engrafted BMSCs under oxidative stress circumstances.