AUTS2 disruption causes neuronal differentiation defects in human cerebral organoids through hyperactivation of the WNT/β-catenin pathway.

Individuals with the Autism Susceptibility Candidate 2 (AUTS2) gene disruptions exhibit symptoms such as intellectual disability, microcephaly, growth retardation, and distinct skeletal and facial differences. The role of AUTS2 in neurodevelopment has been investigated using animal and embryonic stem cell models. However, the precise molecular mechanisms of how AUTS2 influences neurodevelopment, particularly in humans, are not thoroughly understood. Our study employed a 3D human cerebral organoid culture system, in combination with genetic, genomic, cellular, and molecular approaches, to investigate how AUTS2 impacts neurodevelopment through cellular signaling pathways. We used CRISPR/Cas9 technology to create AUTS2-deficient human embryonic stem cells and then generated cerebral organoids with these cells. Our transcriptomic analyses revealed that the absence of AUTS2 in cerebral organoids reduces the populations of cells committed to the neuronal lineage, resulting in an overabundance of cells with a transcription profile resembling that of choroid plexus (ChP) cells. Intriguingly, we found that AUTS2 negatively regulates the WNT/β-catenin signaling pathway, evidenced by its overactivation in AUTS2-deficient cerebral organoids and in luciferase reporter cells lacking AUTS2. Importantly, treating the AUTS2-deficient cerebral organoids with a WNT inhibitor reversed the overexpression of ChP genes and increased the downregulated neuronal gene expression. This study offers new insights into the role of AUTS2 in neurodevelopment and suggests potential targeted therapies for neurodevelopmental disorders.