Inducible XIST-mediated trisomy 21 correction uncovers a USP16-p16 senescence axis driving epileptogenesis in Down syndrome [scRNA-Seq]

Down syndrome (DS), caused by human chromosome 21 (HSA21) trisomy, carries elevated epilepsy risk with unknown mechanisms. We integrated clinical epidemiology, fetal brain single-nucleus RNA sequencing, patient-derived induced pluripotent stem cell (iPSC) models, cerebral organoids, and in vivo chimeric mice to dissect this link. Clinical analysis of 1,365 DS individuals exhibited an age-stratified epilepsy prevalence pattern, with higher rates in older children. Fetal brain transcriptomes revealed neurogenesis defects, aging-related signatures, synaptic/metabolic dysregulation. We engineered an inducible XIST-mediated extra HSA21 silencing system in female DS iPSCs, showing HSA21 dosage correction reduced neural progenitor cell (NPC) senescence markers and neuronal hyperexcitability. Transcriptomic screening pinpointed USP16 as a key pro-aging candidate. Moreover, USP16 suppression and the senolytic combination dasatinib/quercetin reduced senescence-linked and hyperexcitability-associated readouts, supporting a USP16-p16-NPC aging axis as a therapeutic target for DS-associated epilepsy, with broader implications for aging-linked neurological disorders.