Role of ferroptosis in hippocampal neurons induced by Mex3c gene deletion in the pathogenesis of neurodevelopmental disorders

Abstract Introduction: Neurodevelopmental disorders (NDDs) are a heterogeneous group of central nervous system disorders that are strongly influenced by genetic alterations. The RNA-binding protein and E3 ubiquitin ligase MEX3C plays an important role in neurodevelopment. However, its precise contribution to NDD pathogenesis and whether it regulates neuronal ferroptosis remain unclear. Methods To investigate the role of Mex3c in NDDs, we generated Mex3c knockout (KO) mice using CRISPR/Cas9 technology and conducted a series of behavioral tests, histological analyses, and molecular assays. Behavioral phenotyping included the open-field test (OFT), light–dark box test (LDB), and novel object recognition test (NOR). Histological assessments included Nissl staining and NeuN immunohistochemistry to evaluate neuronal injury in the CA1, CA3, and dentate gyrus (DG) regions of the hippocampus. Molecular and biochemical evaluations included Western blotting, immunofluorescence staining, and analysis of ferroptosis- and oxidative stress-related markers, including GPX4, FTH1, NCOA4, reactive oxygen species (ROS), malondialdehyde (MDA), and glutathione (GSH). In addition, the ferroptosis-specific inhibitor Ferrostatin-1 (Fer-1) was administered for in vivo rescue experiments. Results Mex3c KO mice exhibited pronounced NDD-like phenotypes, including anxiety-like behaviors and impaired recognition memory. These behavioral abnormalities were accompanied by neuronal loss and structural damage across multiple hippocampal subregions. Mechanistic analyses revealed that Mex3c deficiency induced ferroptosis in hippocampal neurons, as evidenced by reduced expression of GPX4 and FTH1, increased NCOA4 expression, GSH depletion, and excessive accumulation of ROS and MDA. Pharmacological treatment with Fer-1 markedly suppressed hippocampal ferroptosis and oxidative stress, restored neuronal density, and effectively reversed anxiety-like behaviors and cognitive deficits in Mex3c KO mice. Conclusion Our findings suggest that Mex3c gene deletion disrupts hippocampal antioxidant defense and iron homeostasis through downregulation of GPX4, thereby triggering neuronal ferroptosis and contributing to anxiety-like behavior and recognition memory impairment in mice. These results support Mex3c as a potential susceptibility gene for NDDs and highlight the Mex3c /GPX4/ferroptosis axis as a potential therapeutic target for neurodevelopmental disorders.