Early developmental deletion of forebrain Ank2 causes seizure-related phenotypes by reshaping the synaptic proteome

Rare genetic variants in ANK2, which encodes ankyrin-B, are associated with neurodevelopmental disorders (NDDs); however, their pathogenesis is poorly understood. We find that mice with prenatal deletion in cortical excitatory neurons and oligodendrocytes (Ank2-/-:Emx1-Cre), but not with adolescent deletion in forebrain excitatory neurons (Ank2-/-:CaMKIIa-Cre), display severe spontaneous seizures, increased mortality, hy-peractivity, and social deficits. Calcium imaging of cortical slices from Ank2-/-:Emx1-Cre mice shows increased neuronal calcium event amplitude and frequency, along with network hyperexcitability and hyper -synchrony. Quantitative proteomic analysis of cortical synaptic membranes reveals upregulation of dendritic spine plasticity-regulatory proteins and downregulation of intermediate filaments. Characterization of the ankyrin-B interactome identifies interactors associated with autism and epilepsy risk factors and synaptic proteins. The AMPA receptor antagonist, perampanel, restores cortical neuronal activity and partially res-cues survival in Ank2-/-:Emx1-Cre mice. Our findings suggest that synaptic proteome alterations resulting from Ank2 deletion impair neuronal activity and synchrony, leading to NDDs-related behavioral impairments.

Automated summary

Rare genetic variants in the ANK2 gene are associated with neurodevelopmental disorders (NDDs), but their underlying mechanisms are not well understood. In this study, we found that mice with prenatal deletion of ANK2 in specific neurons showed severe seizures, increased mortality, hyperactivity, and social deficits. Calcium imaging and proteomic analysis revealed alterations in neuronal activity and synaptic proteins in these mice. Treatment with an AMPA receptor antagonist partially rescued the phenotypes. These findings suggest that ANK2 mutations disrupt synaptic proteome and impair neuronal activity, leading to NDD-related behavioral impairments.