Effect of IVNS1ABP mutation, knockout on gene expression during iPSCs differentiation to Neural Progenitors

A homozygous variant in IVNS1ABP was identified in three siblings, displaying progeroid features with severe neuropathy. The association between IVNS1ABP and aging has never been reported before. By generating isogenic iPSCs from the patients’ fibroblasts and differentiating the iPSCs into neural progenitor cells (NPCs), we found that mutant IVNS1ABP fibroblasts, iPSCs, and NPCs exhibited disrupted cytokinesis, DNA damage, and cellular senescence. Transcription analysis of isogenic iPSCs and iPSCs derived neural progenitors (NPCs) also showed impaired cytokinesis and senescence alteration. Correspondingly, cerebral organoids displayed premature differentiation of NPCs to neurons. Molecular profiling as well as biochemical and cellular analysis revealed altered binding of mutant IVNS1ABP to actin and actin-associated proteins and dysregulated actin dynamics during cytokinesis. Taken together, we propose that IVNS1ABP mutation dysregulates actin polymerization and organization which is at least partly responsible for the cellular senescence phenotypes in this undiagnosed disease.