Anti-apoptotic and anti-oxidative effects of DDX24 through HO-1 transcriptional regulation
DEAD-box helicase 24 (DDX24) is a member of the DEAD-box protein family, which is essential for various aspects of RNA metabolism. DDX24 has been reported to play a role in ribosome biogenesis, transcription, and mRNA stability. Previous studies have implicated the functions of DDX24 in innate immunity, vascular malformation, cell growth, and cancer progression. Here, we describe a novel function of DDX24 in regulating the oxidative stress response and protecting cells from apoptosis. Our research revealed that DDX24 specifically regulates the expression of the heme oxygenase-1 (HO-1) gene, as determined by RNA sequencing analysis. HO-1 is responsible for degrading heme into carbon monoxide (CO), biliverdin, and ferrous ion (Fe2+), thereby exerting anti-apoptotic and anti-oxidative effects. We validated the regulation of HO-1 by DDX24 in both DDX24-depleted and DDX24-overexpressing HEK293 cells. Our findings indicate that DDX24 is involved in the induction of HO-1 expression under oxidative stress conditions. Importantly, DDX24 regulates the transcription of HO-1 instead of its mRNA stability, likely acting at the promoter and enhancer E1 region of the HO-1 gene. Furthermore, DDX24 depletion in HEK293T cells inhibits cell viability. DDX24 exerts both anti-apoptotic and anti-oxidative effects during oxidative stress. These results suggest that DDX24 plays a crucial role in protecting cells from oxidative stress-induced damage by regulating the transcription of HO-1.