The neural chaperone proSAAS blocks α-synuclein fibrillation and neurotoxicity

Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaperJournal articleResearchpeer-review

  • Timothy S Jarvela, University of Maryland
  • ,
  • Hoa A Lam, University of California
  • ,
  • Michael Helwig, University of Maryland
  • ,
  • Nikolai Lorenzen
  • ,
  • Daniel E Otzen
  • Pamela J McLean, Mayo Clinic, Jacksonville
  • ,
  • Nigel T Maidment, University of California
  • ,
  • Iris Lindberg, University of Maryland

Emerging evidence strongly suggests that chaperone proteins are cytoprotective in neurodegenerative proteinopathies involving protein aggregation; for example, in the accumulation of aggregated α-synuclein into the Lewy bodies present in Parkinson's disease. Of the various chaperones known to be associated with neurodegenerative disease, the small secretory chaperone known as proSAAS (named after four residues in the amino terminal region) has many attractive properties. We show here that proSAAS, widely expressed in neurons throughout the brain, is associated with aggregated synuclein deposits in the substantia nigra of patients with Parkinson's disease. Recombinant proSAAS potently inhibits the fibrillation of α-synuclein in an in vitro assay; residues 158-180, containing a largely conserved element, are critical to this bioactivity. ProSAAS also exhibits a neuroprotective function; proSAAS-encoding lentivirus blocks α-synuclein-induced cytotoxicity in primary cultures of nigral dopaminergic neurons, and recombinant proSAAS blocks α-synuclein-induced cytotoxicity in SH-SY5Y cells. Four independent proteomics studies have previously identified proSAAS as a potential cerebrospinal fluid biomarker in various neurodegenerative diseases. Coupled with prior work showing that proSAAS blocks β-amyloid aggregation into fibrils, this study supports the idea that neuronal proSAAS plays an important role in proteostatic processes. ProSAAS thus represents a possible therapeutic target in neurodegenerative disease.

Original languageEnglish
JournalProceedings of the National Academy of Sciences of the United States of America
Volume113
Issue32
ISSN0027-8424
DOIs
Publication statusPublished - 25 Jul 2016

See relations at Aarhus University Citationformats

ID: 101581460