CERTL reduces C16 ceramide, amyloid-β levels, and inflammation in a model of Alzheimer’s disease

S.M. Crivelli, Q. Luo, J.A.A. Stevens, C. Giovagnoni, D. van Kruining, G. Bode, S. den Hoedt, B. Hobo, A.L. Scheithauer, J. Walter, M.T. Mulder, C. Exley, M. Mold, M.M. Mielke, H.E. De Vries, K. Wouters, D.L.A. van den Hove, D. Berkes, M.D. Ledesma, J. VerhaagenM. Losen, E. Bieberich, P. Martinez-Martinez*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

6 Citations (Web of Science)

Abstract

BackgroundDysregulation of ceramide and sphingomyelin levels have been suggested to contribute to the pathogenesis of Alzheimer's disease (AD). Ceramide transfer proteins (CERTs) are ceramide carriers which are crucial for ceramide and sphingomyelin balance in cells. Extracellular forms of CERTs co-localize with amyloid-beta (A beta) plaques in AD brains. To date, the significance of these observations for the pathophysiology of AD remains uncertain.MethodsA plasmid expressing CERTL, the long isoform of CERTs, was used to study the interaction of CERTL with amyloid precursor protein (APP) by co-immunoprecipitation and immunofluorescence in HEK cells. The recombinant CERTL protein was employed to study interaction of CERTL with amyloid-beta (A beta), A beta aggregation process in presence of CERTL, and the resulting changes in A beta toxicity in neuroblastoma cells. CERTL was overexpressed in neurons by adeno-associated virus (AAV) in a mouse model of familial AD (5xFAD). Ten weeks after transduction, animals were challenged with behavior tests for memory, anxiety, and locomotion. At week 12, brains were investigated for sphingolipid levels by mass spectrometry, plaques, and neuroinflammation by immunohistochemistry, gene expression, and/or immunoassay.ResultsHere, we report that CERTL binds to APP, modifies A beta aggregation, and reduces A beta neurotoxicity in vitro. Furthermore, we show that intracortical injection of AAV, mediating the expression of CERTL, decreases levels of ceramide d18:1/16:0 and increases sphingomyelin levels in the brain of male 5xFAD mice. CERTL in vivo over-expression has a mild effect on animal locomotion, decreases A beta formation, and modulates microglia by decreasing their pro-inflammatory phenotype.ConclusionOur results demonstrate a crucial role of CERTL in regulating ceramide levels in the brain, in amyloid plaque formation and neuroinflammation, thereby opening research avenues for therapeutic targets of AD and other neurodegenerative diseases.
Original languageEnglish
Article number45
Number of pages21
JournalAlzheimer's Research & Therapy
Volume13
Issue number1
DOIs
Publication statusPublished - 17 Feb 2021

Keywords

  • 5xFAD
  • 5xfad
  • Adeno-associated virus (AAV)
  • Alzheimer's disease (AD)
  • Amyloid-beta plaques
  • Ceramide
  • Ceramide transporter protein (CERT)
  • Microglia
  • Neuroinflammation
  • Sphingomyelin
  • adeno-associated virus (aav)
  • alzheimer's disease (ad)
  • amyloid-beta plaques
  • ceramide
  • ceramide transporter protein (cert)
  • microglia
  • neuroinflammation
  • sphingomyelin
  • ANTIGEN-BINDING PROTEIN
  • 5XFAD MOUSE MODEL
  • PEPTIDE
  • NEURON LOSS
  • BRAIN
  • TRAFFICKING
  • PRECURSOR APP
  • SPHINGOLIPID METABOLISM
  • IN-VIVO
  • TRANSGENIC MICE

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