- Email: [email protected]
NETWORK ANALYSIS OF THE CSF PROTEOME IDENTIFIES SYNAPTIC PROTEINS OF HIPPOCAMPAL ORIGIN AS PUTATIVE BIOMARKERS FOR AD-RELATED SYNAPSE LOSS
P712 P2-258
Poster Presentations: Monday, July 17, 2017 HIGHLY SPECIFIC CSF TAU HYPERPHOSPHORYLATION ON T217 OCCURS SIMULTANEOUSLY WITH AMYLOIDOSIS
Nicolas R. Barthelemy1, Audrey Gabelle2,3, Chihiro Sato1, Sylvain Lehmann2,4, Randall J. Bateman5,6, 1Washington University School of Medicine, St. Louis, MO, USA; 2Universite de Montpellier, Montpellier, France; 3Centre Memoire Ressources Recherche, Departement de Neurologie - CHU Gui de Chauliac, Montpellier, France; 4Laboratoire de Biochimie Proteomique Clinique - CHU Montpellier, Montpellier, France; 5 Washington University School of Medicine, St. Louis, MO, USA; 6Knight Alzheimer’s Disease Research Center, St. Louis, MO, USA. Contact e-mail: [email protected] Background: We previously reported a mass spectrometry (MS)
assay monitoring tau phosphorylation in CSF on 5 sites located on the mid-domain of the tau sequence. Applied to the analysis of a clinical cohort of 50 participants, we highlighted for the first time the highly specific hyperphosphorylation on T217 in AD comparing to others tauopathies. In the current study, we will investigate the relationship between T217 hyperphosphorylation and amyloidosis. Methods: Tau phosphorylation was measured by MS assay on CSF cohort from 83 participants characterized for amyloid status using PiB-PET and CSF Ab42/40 (27 amyloid+, 46 amyloid-, 10 conflictual). CSF tau was immunoprecipitated using Tau1 antibody immobilized on sepharose beads and digested by trypsin. After addition of tau phosphorylated and unphosphorylated labeled peptides used as internal standard, the digest was purified by solid phase extraction. Samples were analyzed by nanoLC-MS/MS. Phosphorylation ratios on T181 and T217 were measured using absolute quantities determined for phosphorylated and corresponding unphosphorylated peptides. Results: The phosphorylation ratio on T217 allows the total discrimination of amyloid+ from amyloid(AUROC 0.999). In comparison, ELISA t-tau and p-tau concentrations provide lower diagnosis power to detect amyloidosis (AUROC 0.932 and 0.874 respectively). Diagnosis power for amyloidosis was also lower using phosphorylation ratio on T181 (AUROC 0.956) and poor when ELISA p-tau(181)/t-tau ratio was used (AUROC 0.795). We found extent of hyperphosphorylation on T217 correlates with amyloid loading measured by PiB (Sperman r¼0.6, p¼0.001). T217 phosphorylation ratio and cognitive decline measured by CDR-SB were not correlated. However, participants with CDR-SB¼0 and amyloidosis (n¼9) were all positive for T217 hyperphosphorylation. Conclusions: Monitoring CSF tau phosphorylation by MS demonstrates for the first time the close relationship existing between T217 hyperphosphorylation and amyloidosis. The detection of T217 hyperphosphorylation in participants having no cognitive decline suggests changes on this tau biomarker would occur early in the course of the disease. These results support the ability of T217 phosphorylation monitoring to reinforce amyloidosis diagnosis by PiB-PET and CSF Ab42/40. This new biomarker significantly improves the confidence in identifying pre symptomatic and mild AD.
P2-259
NETWORK ANALYSIS OF THE CSF PROTEOME IDENTIFIES SYNAPTIC PROTEINS OF HIPPOCAMPAL ORIGIN AS PUTATIVE BIOMARKERS FOR ADRELATED SYNAPSE LOSS
ul N u~ nez-Llaves1, Gemma Gomez-Giro1, Martı ColomOlivia Belbin1, Ra Cadena1, Laura T unez-Bosch1, Daniel Balateu1, Laia Mu~noz-Llahuna1,
Daniel Alcolea2, Estrella Morenas-Rodrıguez1,2, Ignacio Illan-Gala1,2,3, Juan Fortea2,4, Alex Bayes1,5, Alberto Lleo2,3, 1Biomedical Research Institute Sant Pau (IIB Sant Pau), Barcelona, Spain; 2Hospital de la Santa Creu i Sant Pau, Barcelona, Spain; 3Centre of Biomedical Investigation Network for Neurodegenerative Diseases (CIBERNED), Madrid, Spain; 4 Catalan Foundation for Down Syndrome, Barcelona, Spain; 5Universitat Autonoma de Barcelona, Bellaterra (Cerdanyola del Valles), Spain. Contact e-mail: [email protected] Background: A biomarker capable of detecting synapse loss, which
occurs early in Alzheimer’s disease (AD) pathophysiology, would greatly assist in preclinical diagnosis, when treatment would most likely be effective. The objective of this study was to characterise the cerebrospinal fluid (CSF) proteome in terms of regional brain expression, functional and physical relationship to the synapse and interaction complexes in order to identify putative CSF biomarkers that could be used in the clinic to monitor the synaptic loss associated with Alzheimer’s disease. Methods: A database of the CSF proteome was constructed by performing non-targeted liquid chromatography mass spectrometry on CSF samples from 50 cognitively healthy controls and 10 AD patients. A database of the synaptic proteome was constructed by literature curation of proteins detected in synaptosome-enriched fractions or annotated with a synaptic function in online databases. Proteins that were 1) not expressed in the cortical neuropil or cortical neurons or that were highly expressed in cortical or hippocampal glia or 2) whose transcript was not enriched in the hippocampus according to data available from online databases were removed. Results: Cross-referencing the CSF (3,005 proteins) and synaptic (1,056 proteins) proteomes produced a list of 282 proteins. This suggests that approximately 37% of the hippocampal-enriched synaptic proteome is detectable in the CSF by shotgun mass spectrometry and 12% of the CSF proteome is of hippocampal synaptic origin. Construction of an interaction map of the 282 proteins identified functional clusters of proteins that were used to select a panel of proteins for validation as CSF biomarkers for AD. Conclusions: By performing a detailed characterization of the CSF and synaptic proteomes and by confirming synapse expression in human brain, we have identified a panel of synaptic proteins detectable in the CSF which, if confirmed as biomarkers of synaptic loss, could be invaluable stage biomarkers for AD.
P2-260
TWO-LEVEL DIAGNOSTIC CLASSIFICATION USING CEREBROSPINAL FLUID NEUROGRANIN IN ALZHEIMER’S DISEASE
Simone Lista1, Nicola Toschi2,3,4, Filippo Baldacci1,5, Kaj Blennow6, Henrik Zetterberg7,8, Ingo Kilimann9, Stefan J. Teipel9, Enrica Cavedo10,11, Antonio Melo dos Santos12, Stephane Epelbaum12, Foudil Lamari13, Bruno Dubois12, Robert Nistico14, Roberto Floris2, Francesco Garaci2,15, Harald Hampel16, 1AXA Research Fund & UPMC Chair, Sorbonne Universites, Universite Pierre et Marie Curie (UPMC) Paris 06, Inserm, CNRS, Institut du Cerveau et de la Moelle (ICM), Institut de la Memoire et de la Maladie d’Alzheimer (IM2A), Paris, France; 2University of Rome Tor Vergata, Rome, Italy; 3Athinoula A. Martinos Center for Biomedical Imaging, Boston, MA, USA; 4Harvard Medical School, Boston, MA, USA; 5 University of Pisa, Pisa, Italy; 6Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, M€olndal, Sweden; 7 Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden; 8University College London, London, United Kingdom; 9University of Rostock & DZNE Rostock/Greifswald, Rostock,
Poster Presentations: Monday, July 17, 2017 HIGHLY SPECIFIC CSF TAU HYPERPHOSPHORYLATION ON T217 OCCURS SIMULTANEOUSLY WITH AMYLOIDOSIS
Nicolas R. Barthelemy1, Audrey Gabelle2,3, Chihiro Sato1, Sylvain Lehmann2,4, Randall J. Bateman5,6, 1Washington University School of Medicine, St. Louis, MO, USA; 2Universite de Montpellier, Montpellier, France; 3Centre Memoire Ressources Recherche, Departement de Neurologie - CHU Gui de Chauliac, Montpellier, France; 4Laboratoire de Biochimie Proteomique Clinique - CHU Montpellier, Montpellier, France; 5 Washington University School of Medicine, St. Louis, MO, USA; 6Knight Alzheimer’s Disease Research Center, St. Louis, MO, USA. Contact e-mail: [email protected] Background: We previously reported a mass spectrometry (MS)
assay monitoring tau phosphorylation in CSF on 5 sites located on the mid-domain of the tau sequence. Applied to the analysis of a clinical cohort of 50 participants, we highlighted for the first time the highly specific hyperphosphorylation on T217 in AD comparing to others tauopathies. In the current study, we will investigate the relationship between T217 hyperphosphorylation and amyloidosis. Methods: Tau phosphorylation was measured by MS assay on CSF cohort from 83 participants characterized for amyloid status using PiB-PET and CSF Ab42/40 (27 amyloid+, 46 amyloid-, 10 conflictual). CSF tau was immunoprecipitated using Tau1 antibody immobilized on sepharose beads and digested by trypsin. After addition of tau phosphorylated and unphosphorylated labeled peptides used as internal standard, the digest was purified by solid phase extraction. Samples were analyzed by nanoLC-MS/MS. Phosphorylation ratios on T181 and T217 were measured using absolute quantities determined for phosphorylated and corresponding unphosphorylated peptides. Results: The phosphorylation ratio on T217 allows the total discrimination of amyloid+ from amyloid(AUROC 0.999). In comparison, ELISA t-tau and p-tau concentrations provide lower diagnosis power to detect amyloidosis (AUROC 0.932 and 0.874 respectively). Diagnosis power for amyloidosis was also lower using phosphorylation ratio on T181 (AUROC 0.956) and poor when ELISA p-tau(181)/t-tau ratio was used (AUROC 0.795). We found extent of hyperphosphorylation on T217 correlates with amyloid loading measured by PiB (Sperman r¼0.6, p¼0.001). T217 phosphorylation ratio and cognitive decline measured by CDR-SB were not correlated. However, participants with CDR-SB¼0 and amyloidosis (n¼9) were all positive for T217 hyperphosphorylation. Conclusions: Monitoring CSF tau phosphorylation by MS demonstrates for the first time the close relationship existing between T217 hyperphosphorylation and amyloidosis. The detection of T217 hyperphosphorylation in participants having no cognitive decline suggests changes on this tau biomarker would occur early in the course of the disease. These results support the ability of T217 phosphorylation monitoring to reinforce amyloidosis diagnosis by PiB-PET and CSF Ab42/40. This new biomarker significantly improves the confidence in identifying pre symptomatic and mild AD.
P2-259
NETWORK ANALYSIS OF THE CSF PROTEOME IDENTIFIES SYNAPTIC PROTEINS OF HIPPOCAMPAL ORIGIN AS PUTATIVE BIOMARKERS FOR ADRELATED SYNAPSE LOSS
ul N u~ nez-Llaves1, Gemma Gomez-Giro1, Martı ColomOlivia Belbin1, Ra Cadena1, Laura T unez-Bosch1, Daniel Balateu1, Laia Mu~noz-Llahuna1,
Daniel Alcolea2, Estrella Morenas-Rodrıguez1,2, Ignacio Illan-Gala1,2,3, Juan Fortea2,4, Alex Bayes1,5, Alberto Lleo2,3, 1Biomedical Research Institute Sant Pau (IIB Sant Pau), Barcelona, Spain; 2Hospital de la Santa Creu i Sant Pau, Barcelona, Spain; 3Centre of Biomedical Investigation Network for Neurodegenerative Diseases (CIBERNED), Madrid, Spain; 4 Catalan Foundation for Down Syndrome, Barcelona, Spain; 5Universitat Autonoma de Barcelona, Bellaterra (Cerdanyola del Valles), Spain. Contact e-mail: [email protected] Background: A biomarker capable of detecting synapse loss, which
occurs early in Alzheimer’s disease (AD) pathophysiology, would greatly assist in preclinical diagnosis, when treatment would most likely be effective. The objective of this study was to characterise the cerebrospinal fluid (CSF) proteome in terms of regional brain expression, functional and physical relationship to the synapse and interaction complexes in order to identify putative CSF biomarkers that could be used in the clinic to monitor the synaptic loss associated with Alzheimer’s disease. Methods: A database of the CSF proteome was constructed by performing non-targeted liquid chromatography mass spectrometry on CSF samples from 50 cognitively healthy controls and 10 AD patients. A database of the synaptic proteome was constructed by literature curation of proteins detected in synaptosome-enriched fractions or annotated with a synaptic function in online databases. Proteins that were 1) not expressed in the cortical neuropil or cortical neurons or that were highly expressed in cortical or hippocampal glia or 2) whose transcript was not enriched in the hippocampus according to data available from online databases were removed. Results: Cross-referencing the CSF (3,005 proteins) and synaptic (1,056 proteins) proteomes produced a list of 282 proteins. This suggests that approximately 37% of the hippocampal-enriched synaptic proteome is detectable in the CSF by shotgun mass spectrometry and 12% of the CSF proteome is of hippocampal synaptic origin. Construction of an interaction map of the 282 proteins identified functional clusters of proteins that were used to select a panel of proteins for validation as CSF biomarkers for AD. Conclusions: By performing a detailed characterization of the CSF and synaptic proteomes and by confirming synapse expression in human brain, we have identified a panel of synaptic proteins detectable in the CSF which, if confirmed as biomarkers of synaptic loss, could be invaluable stage biomarkers for AD.
P2-260
TWO-LEVEL DIAGNOSTIC CLASSIFICATION USING CEREBROSPINAL FLUID NEUROGRANIN IN ALZHEIMER’S DISEASE
Simone Lista1, Nicola Toschi2,3,4, Filippo Baldacci1,5, Kaj Blennow6, Henrik Zetterberg7,8, Ingo Kilimann9, Stefan J. Teipel9, Enrica Cavedo10,11, Antonio Melo dos Santos12, Stephane Epelbaum12, Foudil Lamari13, Bruno Dubois12, Robert Nistico14, Roberto Floris2, Francesco Garaci2,15, Harald Hampel16, 1AXA Research Fund & UPMC Chair, Sorbonne Universites, Universite Pierre et Marie Curie (UPMC) Paris 06, Inserm, CNRS, Institut du Cerveau et de la Moelle (ICM), Institut de la Memoire et de la Maladie d’Alzheimer (IM2A), Paris, France; 2University of Rome Tor Vergata, Rome, Italy; 3Athinoula A. Martinos Center for Biomedical Imaging, Boston, MA, USA; 4Harvard Medical School, Boston, MA, USA; 5 University of Pisa, Pisa, Italy; 6Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, M€olndal, Sweden; 7 Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden; 8University College London, London, United Kingdom; 9University of Rostock & DZNE Rostock/Greifswald, Rostock,