Autism spectrum disorder (ASD) is a complex neurodevelopmental condition characterized by impairments in social communication and repetitive behaviors, involving various brain regions. Emerging evidence highlights the critical role of the cerebellum in the pathophysiology of autism; however, the underlying molecular mechanisms remain poorly understood. This study aimed to establish a prenatal valproic acid (VPA)-induced mouse model of ASD and explore the potential molecular mechanisms underlying cerebellar ASD-like phenotypes through DIA-based proteomics and bioinformatics analyses. Significant cognitive impairment and anxiety-like behaviors were detected using an open field test and novel object test following VPA exposure, respectively. Additionally, reduced numbers of Purkinje cells with irregular arrangement were observed in the cerebellum. Furthermore, cerebellar proteomics analyses revealed that they identified 193 differentially expressed proteins (DEPs) involved in multiple pathways, including axon guidance, glutamatergic synapse, long-term potentiation, and calcium signaling, among others. Notably, dysfunction of glutamate receptor signaling and disruptions in axon-guidance signaling appear to be major molecular mechanisms underlying cerebellar impairment. Together, these findings suggest that Grin2b may serve as a critical molecule linking synaptic neurotransmission and neurodevelopmental disorders. Thus, Grin2b may represent a potential therapeutic target for addressing cognitive impairment in ASD.

Autism spectrum disorder (ASD) is a neurodevelopmental condition marked by social/communication deficits and behavioral abnormalities, with neuronal apoptosis and immune-inflammatory dysregulation implicated in its pathogenesis. Marine-derived polysaccharides, particularly those from Enteromorpha prolifera (PEPs), exhibit neuroprotective and anti-inflammatory properties—yet their therapeutic potential for ASD remains unexplored. Major monosaccharide components of PEPs were identified as rhamnose, xylose, glucose, glucuronic acid, galactose, and ribose through ion chromatography analysis. Infrared spectroscopy confirmed PEPs as pyranose-type polysaccharides with α-glycosidic bonds and uronic acids, while gel permeation chromatography showed a predominant molecular weight of 3.813 kDa (83.919%). To explore the therapeutic potential of PEPs in ASD, a comprehensive method combining network pharmacology, molecular docking, and in vitro validation was conducted. A total of 235 ASD-related target proteins were predicted, with enrichment analyses indicating significant involvement in pathways such as neuroactive ligand–receptor interaction and the MAPK signaling pathway. In vitro assays using valproic acid (VPA)-induced HT22 neuronal cells showed that PEPs significantly attenuated apoptosis. Western blot analysis further confirmed the downregulation of HSP90AA1, cleaved CASP3/pro-CASP3, p-NF-κB1/NF-κB1, p-AKT1/AKT, and p-mTOR/mTOR, as well as the upregulation of IκBα after PEPs treatment. These findings suggest that PEPs exert neuroprotective effects through the modulation of apoptosis and inflammation-related signaling pathways, supporting their potential as a promising candidate for further study in ASD.