Cell Death and Disease (Nov 2022)

Retinoic acid-induced 1 gene haploinsufficiency alters lipid metabolism and causes autophagy defects in Smith-Magenis syndrome

  • Elisa Maria Turco,
  • Angela Maria Giada Giovenale,
  • Laura Sireno,
  • Martina Mazzoni,
  • Alessandra Cammareri,
  • Caterina Marchioretti,
  • Laura Goracci,
  • Alessandra Di Veroli,
  • Elena Marchesan,
  • Daniel D’Andrea,
  • Antonella Falconieri,
  • Barbara Torres,
  • Laura Bernardini,
  • Maria Chiara Magnifico,
  • Alessio Paone,
  • Serena Rinaldo,
  • Matteo Della Monica,
  • Stefano D’Arrigo,
  • Diana Postorivo,
  • Anna Maria Nardone,
  • Giuseppe Zampino,
  • Roberta Onesimo,
  • Chiara Leoni,
  • Federico Caicci,
  • Domenico Raimondo,
  • Elena Binda,
  • Laura Trobiani,
  • Antonella De Jaco,
  • Ada Maria Tata,
  • Daniela Ferrari,
  • Francesca Cutruzzolà,
  • Gianluigi Mazzoccoli,
  • Elena Ziviani,
  • Maria Pennuto,
  • Angelo Luigi Vescovi,
  • Jessica Rosati

DOI
https://doi.org/10.1038/s41419-022-05410-7
Journal volume & issue
Vol. 13, no. 11
pp. 1 – 16

Abstract

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Abstract Smith-Magenis syndrome (SMS) is a neurodevelopmental disorder characterized by cognitive and behavioral symptoms, obesity, and sleep disturbance, and no therapy has been developed to alleviate its symptoms or delay disease onset. SMS occurs due to haploinsufficiency of the retinoic acid-induced-1 (RAI1) gene caused by either chromosomal deletion (SMS-del) or RAI1 missense/nonsense mutation. The molecular mechanisms underlying SMS are unknown. Here, we generated and characterized primary cells derived from four SMS patients (two with SMS-del and two carrying RAI1 point mutations) and four control subjects to investigate the pathogenetic processes underlying SMS. By combining transcriptomic and lipidomic analyses, we found altered expression of lipid and lysosomal genes, deregulation of lipid metabolism, accumulation of lipid droplets, and blocked autophagic flux. We also found that SMS cells exhibited increased cell death associated with the mitochondrial pathology and the production of reactive oxygen species. Treatment with N-acetylcysteine reduced cell death and lipid accumulation, which suggests a causative link between metabolic dyshomeostasis and cell viability. Our results highlight the pathological processes in human SMS cells involving lipid metabolism, autophagy defects and mitochondrial dysfunction and suggest new potential therapeutic targets for patient treatment.