Clinically early-stage CSPα mutation carrier exhibits remarkable terminal stage neuronal pathology with minimal evidence of synaptic loss

Acta Neuropathol Commun. 2015 Nov 26:3:73. doi: 10.1186/s40478-015-0256-5.

Abstract

Autosomal dominant adult-onset neuronal ceroid lipofuscinosis (AD-ANCL) is a multisystem disease caused by mutations in the DNAJC5 gene. DNAJC5 encodes Cysteine String Protein-alpha (CSPα), a putative synaptic protein. AD-ANCL has been traditionally considered a lysosomal storage disease based on the intracellular accumulation of ceroid material. Here, we report for the first time the pathological findings of a patient in a clinically early stage of disease, which exhibits the typical neuronal intracellular ceroid accumulation and incipient neuroinflammation but no signs of brain atrophy, neurodegeneration or massive synaptic loss. Interestingly, we found minimal or no apparent reductions in CSPα or synaptophysin in the neuropil. In contrast, brain homogenates from terminal AD-ANCL patients exhibit significant reductions in SNARE-complex forming presynaptic protein levels, including a significant reduction in CSPα and SNAP-25. Frozen samples for the biochemical analyses of synaptic proteins were not available for the early stage AD-ANLC patient. These results suggest that the degeneration seen in the patients with AD-ANCL reported here might be a consequence of both the early effects of CSPα mutations at the cellular soma, most likely lysosome function, and subsequent neuronal loss and synaptic dysfunction.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Brain / pathology*
  • Brain / ultrastructure
  • DNA Mutational Analysis
  • Female
  • Gene Expression Regulation / genetics
  • Glial Fibrillary Acidic Protein / metabolism
  • HSP40 Heat-Shock Proteins / genetics*
  • HSP40 Heat-Shock Proteins / metabolism
  • HSP40 Heat-Shock Proteins / ultrastructure
  • Humans
  • Male
  • Membrane Proteins / genetics*
  • Membrane Proteins / metabolism
  • Membrane Proteins / ultrastructure
  • Microscopy, Electron, Transmission
  • Middle Aged
  • Mutation / genetics*
  • Neuronal Ceroid-Lipofuscinoses / genetics*
  • Neuronal Ceroid-Lipofuscinoses / pathology*
  • Neurons / metabolism
  • Neurons / pathology
  • Neurons / ultrastructure
  • Synaptophysin / metabolism

Substances

  • Glial Fibrillary Acidic Protein
  • HSP40 Heat-Shock Proteins
  • Membrane Proteins
  • Synaptophysin
  • cysteine string protein