Increased p53 signaling impairs neural differentiation causing HUWE1-promoted intellectual disabilities

Essential E3 ubiquitin ligase HUWE1 (HECT, UBA and WWE domain containing 1) regulates key factors, as p53. Mutations in HUWE1 have been associated with neurodevelopmental X-linked intellectual disabilities (XLIDs), however the pathomechanism at the onset of heterogenous XLIDs remains unknown. In this work, we identify p53 signaling as the process hyperactivated in lymphoblastoid cells from patients with HUWE1-promoted XLIDs. The hiPSCs-based modeling of the severe HUWE1-promoted XLID, the Juberg Marsidi syndrome (JMS), reviled majorly impaired neural differentiation, accompanied by increased p53 signaling. The impaired differentiation results in loss of cortical patterning and overall undergrowth of XLID JMS patient-specific cerebral organoids, thus closely recapitulating key symptoms, as microcephaly. Importantly, the neurodevelopmental potential of JMS hiPSCs is successfully rescued by restoring p53 signaling, upon reduction of p53 levels. In summary, our findings indicate that increased p53 signaling leads to impaired neural differentiation and is the common cause of neurodevelopmental HUWE1-promoted XLIDs.