TY - JOUR
T1 - CERTL reduces C16 ceramide, amyloid-β levels, and inflammation in a model of Alzheimer’s disease
AU - Crivelli, S.M.
AU - Luo, Q.
AU - Stevens, J.A.A.
AU - Giovagnoni, C.
AU - van Kruining, D.
AU - Bode, G.
AU - den Hoedt, S.
AU - Hobo, B.
AU - Scheithauer, A.L.
AU - Walter, J.
AU - Mulder, M.T.
AU - Exley, C.
AU - Mold, M.
AU - Mielke, M.M.
AU - De Vries, H.E.
AU - Wouters, K.
AU - van den Hove, D.L.A.
AU - Berkes, D.
AU - Ledesma, M.D.
AU - Verhaagen, J.
AU - Losen, M.
AU - Bieberich, E.
AU - Martinez-Martinez, P.
N1 - Funding Information:
This work was supported by grants to NMdW, SdH, MTM, JW, AR, PMM, JV, and HEV from ZonMw Memorabel program (projectnr: 733050105). PMM is also supported by the International Foundation for Alzheimer Research (ISAO) (projectnr: 14545). SMC received a travel grant support from Alzheimer Nederlands foundation (AN) to spend a month in the laboratory of EB, University of Kentucky, Lexington KY, USA. Aspects of this work were supported by the grants NIH R01AG034389, R01NS095215, and R56AG064234; VA I01BX003643 to EB. MMM was supported by R01AG049704.
Funding Information:
We thank Prof. S. Kugler Department of Neurology, University of Gottingen, for the kind gift of adeno-associated virus plasmid. We thank Geertjan van Zonneveld for the professional approach and dedication to complete the illustrations of this research paper.
Publisher Copyright:
© 2021, The Author(s).
PY - 2021/2/17
Y1 - 2021/2/17
N2 - 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.
AB - 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.
KW - 5xFAD
KW - 5xfad
KW - Adeno-associated virus (AAV)
KW - Alzheimer's disease (AD)
KW - Amyloid-beta plaques
KW - Ceramide
KW - Ceramide transporter protein (CERT)
KW - Microglia
KW - Neuroinflammation
KW - Sphingomyelin
KW - adeno-associated virus (aav)
KW - alzheimer's disease (ad)
KW - amyloid-beta plaques
KW - ceramide
KW - ceramide transporter protein (cert)
KW - microglia
KW - neuroinflammation
KW - sphingomyelin
KW - ANTIGEN-BINDING PROTEIN
KW - 5XFAD MOUSE MODEL
KW - PEPTIDE
KW - NEURON LOSS
KW - BRAIN
KW - TRAFFICKING
KW - PRECURSOR APP
KW - SPHINGOLIPID METABOLISM
KW - IN-VIVO
KW - TRANSGENIC MICE
U2 - 10.1186/s13195-021-00780-0
DO - 10.1186/s13195-021-00780-0
M3 - Article
C2 - 33597019
SN - 1758-9193
VL - 13
JO - Alzheimer's Research & Therapy
JF - Alzheimer's Research & Therapy
IS - 1
M1 - 45
ER -