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Poster Presentations: Monday, July 25, 2016 CEREBROSPINAL FLUID BIOMARKER PROFILE OF AMYLOID, TAU, SYNAPTIC, MICROGLIAL, AND LYSOSOMAL PATHOPHYSIOLOGY IN COGNITIVELY NORMAL PRECLINICAL INDIVIDUALS STRATIFIED BY AMYLOID-PET STATUS
Harald Hampel1, Simone Lista2, Henrik Zetterberg3, Kaj Blennow3, Marie-Odile Habert4, Francis Nyasse5, Hovagim Bakardjian6, Foudil Lamari7, Bruno Dubois8, 1Sorbonne Universites, Universite Pierre et Marie Curie, Paris, France; 2Sorbonne Universites, Universite Pierre et Marie Curie (UPMC), Paris, France; 3Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden; 4Sorbonne Universites, UPMC Univ Paris 06, Inserm U 1146, CNRS UMR 7371, Laboratoire d’Imagerie Biomedicale, Paris, France; 5Institut de la Memoire et de la Maladie d’Alzheimer (IM2A), Paris, France; 6IHU-A-ICM - Paris Institute of Translational Neurosciences, Hopital Pitie-Salpetriere, Paris, France; 7Service de Biochimie Metabolique, H^ opital Pitie-Salp^etriere, Paris, France; 8Sorbonne Universite, Universite Pierre et Marie Curie-Paris 6, Paris, France. Contact e-mail:
[email protected] Background: Disease-modifying treatments against Alzheimer’s dis-
ease (AD) should be tested during the preclinical stage before the occurrence of widespread irreversible pathological brain damage. Biomarker candidates indicative of the preclinical AD stage are in discovery and development. We performed advanced cerebrospinal fluid (CSF) candidate biomarker characterization in cognitively normal preclinical individuals at increased risk of AD stratified by brain amyloid load to assess amyloid/tau pathophysiology in correlation with synaptic, inflammatory, and lysosomal dysfunction. Methods: The mono-centric INSIGHT cohort (Piti e-Salp^etriere University Hospital, Paris) was used with a target population of cognitively normal elderly individuals stratified by amyloid PET (18F-AV45 [AmyvidÔ]). CSF was analysed for a panel of innovative candidate biomarkers: neurofilament light polypeptide (large-calibre myelinated axons marker), neurogranin and synaptotagmin (synaptic degeneration markers), Ab1-42/Ab1-40, Ab1-42/Ab1-38 ratios, Ab oligomers (amyloid markers), N-terminal and mid-domain tau (neurodegeneration markers), YKL-40 (microglial marker). Additionally, a mass spectrometry (MS)-based panel for lysosomal markers was utilized. All measures were related both to amyloid/tau pathophysiology and to clinical disease progression. Standardized CSF samples obtained from an INSIGHT cohort subset of 31 subjects (21 amyloid PET(-), 10 amyloid PET(+); age¼75.2 [71.5–78.9]; MMSE¼29 [28–30]; FCSRT¼45.5 [43.2–47.8]; APOE genotype: ε2/ε3 [9.7%], ε3/ε3 [64.5%], ε3/ε4 [25.8%]) was investigated using different analysis methods, such as ELISA, electrochemiluminescence-based immunoassays, ultrasensitive Single-Molecule Array (Simoa) or parallel reaction monitoring MS (PRM-MS) technologies. Results: All data and results will be presented at the conference. Conclusions: We present a comprehensive panel of novel CSF candidate biomarkers reflecting different pathophysiological mechanisms during the preclinical stage of AD. This will help characterize initiated pathophysiological mechanisms of action driving amyloid accumulation and AD progression during the preclinical stage and support early disease detection and identification of molecular mechanisms as targets for therapeutic intervention. P2-152
CHARACTERIZATION OF THE POSTSYNAPTIC PROTEIN NEUROGRANIN IN DIFFERENT BRAIN REGIONS IN PATIENTS WITH FAMILIAL ALZHEIMER’S DISEASE, ALZHEIMER’S DISEASE, PATHOLOGICAL AGING AND HEALTHY CONTROLS
Hlin Kvartsberg1, Tammaryn Lashley2, Christina E. Murray3, Henrik Zetterberg4, Kaj Blennow4, Erik Portelius4, 1The Sahlgrenska Academy, Institute of Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden; 2University College London, London, United Kingdom; 3University College London, Institute of Neurology, London, United Kingdom; 4Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden. Contact e-mail:
[email protected] Background: Synaptic degeneration and neuronal loss are believed
to occur early in the course of Alzheimer’s disease (AD), probably long before the onset of the first symptoms. Thus, synaptic proteins are highly relevant for enabling early diagnosis. The postsynaptic protein neurogranin (Ng) has recently emerged as a promising novel biomarker for AD as we and others have shown that cerebrospinal fluid Ng is increased in both AD patients as well as patients with prodromal AD. In a previous pilot study on brain tissue from AD patients and healthy controls we showed that 10 of 13 measured Ng peptides increase in AD while full-length protein is decreased compared to controls. In the current study we aim to follow up on these results by characterizing and relatively quantifying endogenous Ng peptides as well as full-length protein in three brain regions from patients with AD, familial AD (FAD), pathological aging (PA, brains with Ab and tau deposition but with no signs of cognitive impairment during life) and healthy controls. Methods: Brain tissue (temporal cortex, cerebellum and striatum) from AD patients (n¼9), FAD patients (n¼10), PA individuals (n¼5) and age matched healthy controls (n¼4) was homogenized in TBS and centrifuged at 31000 x g at +4 C for 1 h. The supernatant was removed and stored at –80 C pending analysis. All samples were analyzed by immunoprecipitation (IP) followed by MALDI-TOF/TOF mass spectrometry. The IP was performed using in-house-generated monoclonal anti-human Ng antibodies targeting the C-terminal region of the protein. The FAD group consisted of mutations in either PSN1 or APP. Results: Ng peptides and fulllength protein were present in both temporal cortex and striatum but not cerebellum. PA had significantly more full-length Ng in temporal cortex compared to all other groups (p<0.05). In contrast, peptide concentrations in all brain regions were similar to healthy controls. For FAD, several peptides were elevated compared to healthy controls (p<0.05). Conclusions: We have for the first time quantified Ng in brain tissue from FAD and PA individuals. Ng expression in PA seems to be distinctly different compared to AD, FAD and healthy controls, especially with regard to intact Ng.
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DIAGNOSTIC PERFORMANCE OF NONPHOSPHORYLATED TAU FRACTION (PTAU REL) IN CSF AS BIOMARKER FOR DIFFERENTIAL DEMENTIA DIAGNOSIS
Joery Goossens1, Hanne Struyfs1, Ellis Niemantsverdriet1, Tobi Van den Bossche2,3,4,5, Sara Van Mossevelde2,3,4,5, Bart De Vil6, Anne Sieben2,7, Jean-Jacques Martin7, Patrick Cras4,6, Johan Goeman3, Peter Paul de Deyn3,7, Christine Van Broeckhoven2,5, Julie van der Zee2,5, Sebastiaan Engelborghs1,3, 1Reference Center for Biological Markers of Dementia (BIODEM), Laboratory of Neurochemistry and Behavior, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium; 2 Neurodegenerative Brain Diseases Group, Department of Molecular Genetics, VIB, Antwerp, Belgium; 3Department of Neurology and Memory Clinic, Hospital Network Antwerp (ZNA) Middelheim and Hoge Beuken, Antwerp, Belgium; 4Department of Neurology, Antwerp University