WTAP regulates NCOA4-mediated ferroptosis via a YTHDF2-dependent mechanism in preeclampsia

Preeclampsia (PE) is a pregnancy-specific hypertensive disorder associated with placental dysfunction and oxidative stress. This study explored whether WTAP regulates ferroptosis in trophoblasts through m⁶A-dependent control of NCOA4 and YTHDF2.

WTAP expression and global m⁶A levels in PE placentas were examined by qRT-PCR, western blot, and immunohistochemistry, along with histopathological analysis. WTAP, NCOA4, and YTHDF2 expression were manipulated in HTR-8/SVneo trophoblasts using siRNAs or overexpression plasmids. Cell proliferation, migration, cell-cycle distribution, oxidative stress, and ferroptosis markers were evaluated. MeRIP-qPCR and RIP-qPCR were used to assess NCOA4 m⁶A methylation and YTHDF2 binding. A PE mouse model was established to assess in vivo effects and the potential rescue by Ferrostatin-1 (Fer-1).

WTAP expression and global m⁶A levels were reduced in PE placentas, accompanied by villous structural damage. Functionally, WTAP knockdown suppressed trophoblast proliferation and migration, induced G1 arrest, and enhanced oxidative stress, while WTAP overexpression had opposite effects. Mechanistically, WTAP promoted m⁶A methylation of NCOA4 mRNA and its YTHDF2-dependent degradation. In PE placentas, YTHDF2 was downregulated and NCOA4 upregulated, consistent with in vitro findings. NCOA4 overexpression impaired trophoblast function and increased ferroptosis, whereas silencing had protective effects. YTHDF2 knockdown and NCOA4 overexpression acted synergistically to exacerbate ferroptosis, both in trophoblasts and in a PE mouse model, leading to aggravated hypertension, proteinuria, and fetal growth restriction, which were partially reversed by Fer-1.

WTAP suppresses ferroptosis in PE by enhancing YTHDF2-dependent m⁶A methylation and degradation of NCOA4. Disruption of this pathway exacerbates oxidative stress, trophoblast dysfunction, and adverse pregnancy outcomes.