Epitranscriptomic m6A reader HNRNPC amplifies oxidative stress–autophagy dysregulation and aggravates placental dysfunction in preeclampsia

Preeclampsia (PE) is a placenta-driven hypertensive disorder characterized by oxidative stress, mitochondrial dysfunction, and abnormal autophagy. However, how these stress-response programs are coordinated at the post-transcriptional level remains incompletely understood. We integrated transcriptomic, proteomic, and untargeted metabolomic profiling of placentas from PE patients and normotensive controls, followed by validation in an independent clinical cohort. Mechanistic roles were interrogated using hypoxia-treated HTR-8/SVneo trophoblasts and an L-NAME-induced PE-like mouse model. Autophagy dynamics were assessed using dual-fluorescent autophagic flux reporters, transmission electron microscopy, and molecular markers. Multi-omics analyses converged on oxidative stress-related pathways, oxidative phosphorylation, and autophagy. The m6A reader HNRNPC was selectively upregulated at the protein level in PE placentas and positively correlated with the autophagy-related SNARE protein SEC22B. Clinically, PE placentas exhibited elevated global m6A methylation, increased HNRNPC and SEC22B expression, enhanced autophagic activity, and excessive oxidative stress. In trophoblasts, hypoxia induced ROS and autophagy, while HNRNPC overexpression further amplified intracellular and mitochondrial ROS, enhanced autophagic flux, and promoted apoptosis. In vivo, placental overexpression of HNRNPC aggravated hypertension, proteinuria, placental structural damage, oxidative stress, and autophagy dysregulation in PE-like mice. Our findings implicate a potential HNRNPC-SEC22B-autophagy regulatory network that amplifies placental stress maladaptation in preeclampsia. This study links epitranscriptomic remodeling to redox and autophagy dysregulation, suggesting HNRNPC as a potential mechanistic hub and therapeutic target in PE.