Proteasome mutations associated with CANDLE syndrome cause altered neuronal development by dysregulating polyamine synthesis.

Loss-of-function mutations in PSMB8/beta5i and other components of the 20S proteasome result in multi-organ diseases, such as Chronic atypical neutrophilic dermatosis with lipodystrophy and elevated temperature (CANDLE) syndrome. Neurocognitive dysfunction associated with CANDLE suggests that proteasomal mutations may impact neuronal function and development early in life. We generated cerebral organoids (COs) from induced pluripotent stem cells (iPSCs) made from CANDLE patients. The COs from CANDLE iPSCs exhibited impaired neuronal development when compared to COs from healthy control iPSCs. Impaired neuronal maturation in CANDLE COs was correlated with increased polyamines, which were also elevated in CANDLE patient CSF. The proteasome-regulated Ornithine decarboxylase (ODC), the rate limiting enzyme in polyamine biosynthesis, was elevated in CANDLE neurons. Inhibition of ODC reversed polyamine overproduction and repaired neuronal maturation in CANDLE COs, suggesting a potential therapeutic avenue for intervention. These findings demonstrate that dysfunction of the proteasome affects neuronal development through overproduction of polyamines via dysregulation of ODC and offer insight into potential therapeutic strategies for CNS-related proteasomal dysfunction.