PAD2 dysregulation and aberrant protein citrullination feature prominently in reactive astrogliosis and myelin protein aggregation in sporadic ALS

Neurobiol Dis. 2024 Mar:192:106414. doi: 10.1016/j.nbd.2024.106414. Epub 2024 Jan 21.

Abstract

Alteration in protein citrullination (PC), a common posttranslational modification (PTM), contributes to pathogenesis in various inflammatory disorders. We previously reported that PC and protein arginine deiminase 2 (PAD2), the predominant enzyme isoform that catalyzes this PTM in the central nervous system (CNS), are altered in mouse models of amyotrophic lateral sclerosis (ALS). We now demonstrate that PAD2 expression and PC are altered in human postmortem ALS spinal cord and motor cortex compared to controls, increasing in astrocytes while trending lower in neurons. Furthermore, PC is enriched in protein aggregates that contain the myelin proteins PLP and MBP in ALS. These results confirm our findings in ALS mouse models and suggest that altered PAD2 and PC contribute to neurodegeneration in ALS.

Keywords: Deimination; Myelin degeneration; Neurodegeneration; Neurodegenerative disease; Neuroinflammation; Protein aggregation.

MeSH terms

  • Amyotrophic Lateral Sclerosis* / metabolism
  • Animals
  • Citrullination*
  • Gliosis / metabolism
  • Humans
  • Hydrolases / genetics
  • Hydrolases / metabolism
  • Mice
  • Myelin Proteins / metabolism
  • Myelin Sheath / pathology
  • Protein Aggregates
  • Protein-Arginine Deiminase Type 2 / metabolism
  • Protein-Arginine Deiminases / metabolism
  • Proteins / metabolism
  • Spinal Cord / pathology

Substances

  • Hydrolases
  • Myelin Proteins
  • Protein Aggregates
  • Protein-Arginine Deiminase Type 2
  • Protein-Arginine Deiminases
  • Proteins
  • PADI2 protein, human

Supplementary concepts

  • Amyotrophic lateral sclerosis 1