Esculetin ameliorates autism-like behaviors in GABAergic neuron-specific Pax2 knockdown mice, accompanied by reduced Wnt/β-catenin signaling.

Autism spectrum disorder (ASD) is a neurodevelopmental disorder with an unclear pathogenesis. Growing evidence implicates excitatory/inhibitory (E/I) imbalance in ASD pathophysiology, prompting an investigation into gamma-aminobutyric acid (GABA)-mediated inhibitory transmission. The transcription factor Paired Box 2 (Pax2), essential for GABAergic interneuron specification, participates in the regulation of neural developmental processes. Our previous work demonstrated an E/I imbalance in the neurotransmitter system and reduced GABAARα2-positive neurons in the prefrontal cortex (PFC) of Pax2 neuron-specific deletion mice, though the internal molecular regulatory mechanism remained elusive. In this study, we generated GABAergic neuron-specific Pax2 knockdown mice via injection of AAV-shPax2 virus and comprehensively evaluated ASD-related behaviors, revealing autism-like behaviors, such as impaired social novelty and repetitive behaviors. Molecular analysis revealed upregulation of Tcf7l2, a key downstream mediator of the Wnt/β-catenin signaling pathway. Functional assessment confirmed hyperactivation of the Wnt/β-catenin signaling pathway in GABAergic neuron Pax2 knockdown mice. Notably, pharmacological intervention with esculetin, an inhibitor of the Wnt/β-catenin pathway, ameliorated the observed autism-like behaviors. These findings establish a pathogenic axis wherein GABAergic neuron-specific Pax2 deficiency induces hyperactivation of the Wnt/β-catenin signaling pathway and disrupts E/I balance, ultimately driving autism-like behavioral phenotypes. Our results further identify inhibition of Wnt/β-catenin signaling as a promising therapeutic strategy for ASD.