%0 Journal Article %J J Alzheimers Dis %D 2020 %T Dickkopf-1 Overexpression in vitro Nominates Candidate Blood Biomarkers Relating to Alzheimer's Disease Pathology. %A Shi, Liu %A Winchester, Laura M %A Liu, Benjamine Y %A Killick, Richard %A Ribe, Elena M %A Westwood, Sarah %A Baird, Alison L %A Buckley, Noel J %A Hong, Shengjun %A Dobricic, Valerija %A Kilpert, Fabian %A Franke, Andre %A Kiddle, Steven %A Sattlecker, Martina %A Dobson, Richard %A Cuadrado, Antonio %A Hye, Abdul %A Ashton, Nicholas J %A Morgan, Angharad R %A Bos, Isabelle %A Vos, Stephanie J B %A Ten Kate, Mara %A Scheltens, Philip %A Vandenberghe, Rik %A Gabel, Silvy %A Meersmans, Karen %A Engelborghs, Sebastiaan %A De Roeck, Ellen E %A Sleegers, Kristel %A Frisoni, Giovanni B %A Blin, Olivier %A Richardson, Jill C %A Bordet, Régis %A Molinuevo, José L %A Rami, Lorena %A Wallin, Anders %A Kettunen, Petronella %A Tsolaki, Magda %A Verhey, Frans %A Lleo, Alberto %A Alcolea, Daniel %A Popp, Julius %A Peyratout, Gwendoline %A Martínez-Lage, Pablo %A Tainta, Mikel %A Johannsen, Peter %A Teunissen, Charlotte E %A Freund-Levi, Yvonne %A Frölich, Lutz %A Legido-Quigley, Cristina %A Barkhof, Frederik %A Blennow, Kaj %A Rasmussen, Katrine Laura %A Nordestgaard, Børge Grønne %A Frikke-Schmidt, Ruth %A Nielsen, Sune Fallgaard %A Soininen, Hilkka %A Vellas, Bruno %A Kloszewska, Iwona %A Mecocci, Patrizia %A Zetterberg, Henrik %A Morgan, B Paul %A Streffer, Johannes %A Visser, Pieter Jelle %A Bertram, Lars %A Nevado-Holgado, Alejo J %A Lovestone, Simon %X

BACKGROUND: Previous studies suggest that Dickkopf-1 (DKK1), an inhibitor of Wnt signaling, plays a role in amyloid-induced toxicity and hence Alzheimer's disease (AD). However, the effect of DKK1 expression on protein expression, and whether such proteins are altered in disease, is unknown.

OBJECTIVE: We aim to test whether DKK1 induced protein signature obtained in vitro were associated with markers of AD pathology as used in the amyloid/tau/neurodegeneration (ATN) framework as well as with clinical outcomes.

METHODS: We first overexpressed DKK1 in HEK293A cells and quantified 1,128 proteins in cell lysates using aptamer capture arrays (SomaScan) to obtain a protein signature induced by DKK1. We then used the same assay to measure the DKK1-signature proteins in human plasma in two large cohorts, EMIF (n = 785) and ANM (n = 677).

RESULTS: We identified a 100-protein signature induced by DKK1 in vitro. Subsets of proteins, along with age and apolipoprotein E ɛ4 genotype distinguished amyloid pathology (A + T-N-, A+T+N-, A+T-N+, and A+T+N+) from no AD pathology (A-T-N-) with an area under the curve of 0.72, 0.81, 0.88, and 0.85, respectively. Furthermore, we found that some signature proteins (e.g., Complement C3 and albumin) were associated with cognitive score and AD diagnosis in both cohorts.

CONCLUSIONS: Our results add further evidence for a role of DKK regulation of Wnt signaling in AD and suggest that DKK1 induced signature proteins obtained in vitro could reflect theATNframework as well as predict disease severity and progression in vivo.

%B J Alzheimers Dis %V 77 %P 1353-1368 %8 2020 Sep 29 %G eng %N 3 %R 10.3233/JAD-200208 %0 Journal Article %J J Alzheimers Dis %D 2020 %T Validation of Plasma Proteomic Biomarkers Relating to Brain Amyloid Burden in the EMIF-Alzheimer's Disease Multimodal Biomarker Discovery Cohort. %A Westwood, Sarah %A Baird, Alison L %A Anand, Sneha N %A Nevado-Holgado, Alejo J %A Kormilitzin, Andrey %A Shi, Liu %A Hye, Abdul %A Ashton, Nicholas J %A Morgan, Angharad R %A Bos, Isabelle %A Vos, Stephanie J B %A Baker, Susan %A Buckley, Noel J %A Ten Kate, Mara %A Scheltens, Philip %A Teunissen, Charlotte E %A Vandenberghe, Rik %A Gabel, Silvy %A Meersmans, Karen %A Engelborghs, Sebastiaan %A De Roeck, Ellen E %A Sleegers, Kristel %A Frisoni, Giovanni B %A Blin, Olivier %A Richardson, Jill C %A Bordet, Régis %A Molinuevo, José L %A Rami, Lorena %A Wallin, Anders %A Kettunen, Petronella %A Tsolaki, Magda %A Verhey, Frans %A Lleo, Alberto %A Sala, Isabel %A Popp, Julius %A Peyratout, Gwendoline %A Martínez-Lage, Pablo %A Tainta, Mikel %A Johannsen, Peter %A Freund-Levi, Yvonne %A Frölich, Lutz %A Dobricic, Valerija %A Legido-Quigley, Cristina %A Bertram, Lars %A Barkhof, Frederik %A Zetterberg, Henrik %A Morgan, B Paul %A Streffer, Johannes %A Visser, Pieter Jelle %A Lovestone, Simon %X

We have previously investigated, discovered, and replicated plasma protein biomarkers for use to triage potential trials participants for PET or cerebrospinal fluid measures of Alzheimer's disease (AD) pathology. This study sought to undertake validation of these candidate plasma biomarkers in a large, multi-center sample collection. Targeted plasma analyses of 34 proteins with prior evidence for prediction of in vivo pathology were conducted in up to 1,000 samples from cognitively healthy elderly individuals, people with mild cognitive impairment, and in patients with AD-type dementia, selected from the EMIF-AD catalogue. Proteins were measured using Luminex xMAP, ELISA, and Meso Scale Discovery assays. Seven proteins replicated in their ability to predict in vivo amyloid pathology. These proteins form a biomarker panel that, along with age, could significantly discriminate between individuals with high and low amyloid pathology with an area under the curve of 0.74. The performance of this biomarker panel remained consistent when tested in apolipoprotein E ɛ4 non-carrier individuals only. This blood-based panel is biologically relevant, measurable using practical immunocapture arrays, and could significantly reduce the cost incurred to clinical trials through screen failure.

%B J Alzheimers Dis %V 74 %P 213-225 %8 2020 %G eng %N 1 %1 https://www.ncbi.nlm.nih.gov/pubmed/31985466?dopt=Abstract %R 10.3233/JAD-190434 %0 Journal Article %J J Alzheimers Dis %D 2018 %T Predicting and Tracking Short Term Disease Progression in Amnestic Mild Cognitive Impairment Patients with Prodromal Alzheimer's Disease: Structural Brain Biomarkers. %A Marizzoni, Moira %A Ferrari, Clarissa %A Jovicich, Jorge %A Albani, Diego %A Babiloni, Claudio %A Cavaliere, Libera %A Didic, Mira %A Forloni, Gianluigi %A Galluzzi, Samantha %A Hoffmann, Karl-Titus %A Molinuevo, José Luis %A Nobili, Flavio %A Parnetti, Lucilla %A Payoux, Pierre %A Ribaldi, Federica %A Rossini, Paolo Maria %A Schönknecht, Peter %A Soricelli, Andrea %A Hensch, Tilman %A Tsolaki, Magda %A Visser, Pieter Jelle %A Wiltfang, Jens %A Richardson, Jill C %A Bordet, Régis %A Blin, Olivier %A Frisoni, Giovanni B %X

BACKGROUND: Early Alzheimer's disease (AD) detection using cerebrospinal fluid (CSF) biomarkers has been recommended as enrichment strategy for trials involving mild cognitive impairment (MCI) patients.

OBJECTIVE: To model a prodromal AD trial for identifying MRI structural biomarkers to improve subject selection and to be used as surrogate outcomes of disease progression.

METHODS: APOE ɛ4 specific CSF Aβ42/P-tau cut-offs were used to identify MCI with prodromal AD (Aβ42/P-tau positive) in the WP5-PharmaCog (E-ADNI) cohort. Linear mixed models were performed 1) with baseline structural biomarker, time, and biomarker×time interaction as factors to predict longitudinal changes in ADAS-cog13, 2) with Aβ42/P-tau status, time, and Aβ42/P-tau status×time interaction as factors to explain the longitudinal changes in MRI measures, and 3) to compute sample size estimation for a trial implemented with the selected biomarkers.

RESULTS: Only baseline lateral ventricle volume was able to identify a subgroup of prodromal AD patients who declined faster (interaction, p = 0.003). Lateral ventricle volume and medial temporal lobe measures were the biomarkers most sensitive to disease progression (interaction, p≤0.042). Enrichment through ventricular volume reduced the sample size that a clinical trial would require from 13 to 76%, depending on structural outcome variable. The biomarker needing the lowest sample size was the hippocampal subfield GC-ML-DG (granule cells of molecular layer of the dentate gyrus) (n = 82 per arm to demonstrate a 20% atrophy reduction).

CONCLUSION: MRI structural biomarkers can enrich prodromal AD with fast progressors and significantly decrease group size in clinical trials of disease modifying drugs.

%B J Alzheimers Dis %8 2018 Jun 09 %G eng %R 10.3233/JAD-180152 %0 Journal Article %J J Alzheimers Dis %D 2017 %T Longitudinal Characterization of [18F]-FDG and [18F]-AV45 Uptake in the Double Transgenic TASTPM Mouse Model. %A Waldron, Ann-Marie %A Wyffels, Leonie %A Verhaeghe, Jeroen %A Richardson, Jill C %A Schmidt, Mark %A Stroobants, Sigrid %A Langlois, Xavier %A Staelens, Steven %X

We aimed to monitor the timing of amyloid-β deposition in relation to changes in brain function using in vivo imaging with [18F]-AV45 and [18F]-FDG in a mouse model of Alzheimer's disease. TASTPM transgenic mice and wild-type controls were scanned longitudinally with [18F]-AV45 and [18F]-FDG before (3 months of age) and at multiple time points after the onset of amyloid deposition (6, 9, 12, and 15 months of age). As expected with increasing amyloidosis, TASTPM mice demonstrated progressive age-dependent increases in [18F]-AV45 uptake that were significantly higher than for WT from 9 months onwards and correlated to ex vivo measures of amyloid burden. The metabolism of [18F]-AV45 produces several brain penetrant radiometabolites and normalization to a reference region helps to negate this non-specific binding and improve the sensitivity of [18F]-AV45. The observed trajectory of [18F]-FDG alterations deviated from our proposed hypothesis of gradual decreases with worsening amyloidosis. While [18F]-FDG uptake in TASTPM mice was significantly lower than that of WT at 9 months, reduced [18F]-FDG was not associated with aging in TASTPM mice. Moreover, [18F]-FDG uptake did not correlate to measures of ex vivo amyloid burden. Our findings suggest that while amyloid-β is sufficient to induce hypometabolism, these pathologies are not linked in a dose-dependent manner in TASTPM mice.

%B J Alzheimers Dis %V 55 %P 1537-1548 %8 2017 %G eng %N 4 %1 http://www.ncbi.nlm.nih.gov/pubmed/27911309?dopt=Abstract %R 10.3233/JAD-160760 %0 Journal Article %J J Alzheimers Dis %D 2015 %T The Continuing Failure of Bexarotene in Alzheimer's Disease Mice. %A Balducci, Claudia %A Paladini, Alessandra %A Micotti, Edoardo %A Tolomeo, Daniele %A La Vitola, Pietro %A Grigoli, Emanuele %A Richardson, Jill C %A Forloni, Gianluigi %X

Alzheimer's disease (AD) is the most common form of dementia characterized by synaptic dysfunction, memory loss, neuroinflammation, and neuronal cell death. Amyloid-β (Aβ), recognized as the main culprit of AD, aggregates and accumulates in the extracellular compartment as neuritic plaques, after deregulation of its production or clearance. Apolipoprotein E (ApoE) plays a major role in Aβ clearance and its expression is transcriptionally regulated by the liver X receptor and retinoid X receptors (RXRs) system. Bexarotene (BEXA), an RXR agonist, that increases ApoE expression and microglia phagocytosis and has been proposed as a promising therapy for AD, resolving both the amyloid pathology and memory loss. Despite the first compelling report, however, multiple failures have been documented, raising concern about whether BEXA could in fact become a novel disease-modifying strategy for AD. To help clarify this, we investigated the effect of BEXA in vivo at multiple levels in TASTPM transgenic mice. Seven-day oral administration of BEXA to these mice did not achieve any significant memory improvement, plaque reduction, or enhancement of microglial cell activation. No differences were found when specifically investigating the microglial phagocytic state in vivo. In addition, a brain structural analysis with magnetic resonance did not detect any BEXA-mediated change in the volume reduction of the main affected brain areas in our mice. These results suggest that BEXA has no beneficial effect on the multi-factorial pathologic phenotype of AD mice.

%B J Alzheimers Dis %8 2015 Mar 16 %G eng %R 10.3233/JAD-150029