EFFECTS OF AEROBIC-STRENGTH TRAINING ON SELECTED MOLECULAR TARGETS IN CEREBROSPINAL FLUID OF SENIORS WITH MILD COGNITIVE IMPAIRMENT

Poster Presentations: Monday, July 25, 2016 Hospital, Antwerp, Belgium; 5Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium; 6Laboratory of Neurobiology, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium; 7Biobank, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium. Contact e-mail: [email protected] Background: Cerebrospinal fluid (CSF) levels of total tau protein (hTau), phosphorylated tau (pTau181P), and amyloid-beta of 42 amino acids (Ab1-42) are established biomarkers for the diagnosis of Alzheimer’s disease (AD), but the discriminatory power for differential dementia diagnosis remains suboptimal. Also, current laboratory measures of CSF pTau181P are thought to underestimate the total levels of phosphorylated tau. The goal of this study is to investigate if the non-phosphorylated tau fraction (pTau rel) would improve the diagnostic performance of the routine AD biomarker panel for differential dementia diagnosis. Methods: The study population consisted of clinically diagnosed AD patients (n¼45), definite frontotemporal lobar degeneration (FTLD) patients (n¼45), definite Creutzfeldt-Jakob disease (CJD) patients (n¼20) and cognitively healthy controls (n¼20). CSF levels of Ab1-42, hTau, pTau181P and pTau rel were determined with commercially available single-analyte ELISA kits (INNOTEST b-Amyloid(142 ), INNOTEST hTau-Ag and INNOTEST Phospho-Tau( 181P) from Fujirebio Europe, Belgium; pTAU rel ELISA Kit from AJ Roboscreen, IBL International GmbH, Germany). Receiver operating characteristic (ROC) curve analyses were used to obtain area under the curve (AUC) values. AUC values were compared using DeLong tests. Results: Diagnostic performance

Table 1 Diagnostic performance of routine AD biomarkers compared to pTau rel. The first column contains AUC values for the single markers and biomarker ratios with the highest diagnostic value. Other columns show AUC values of pTau rel and the equivalent ratio using pTau rel. Significant differences between AUC values (p<0.05) are marked with an asterisk (*) when difference is positive (i.e. significant higher diagnostic power when using pTau rel), and with a degree sign ( ) when difference is negative (i.e. significant lower diagnostic power when using pTau rel).

AD vs. controls hTau Ab1-42 /hTau FTLD vs. controls Ab1-42 pTau/hTau CJD vs. controls hTau Ab1-42 /hTau AD vs. FTLD pTau Ab1-42 /pTau AD vs. CJD hTau pTau/hTau FTLD vs. CJD hTau pTau/hTau

AUC

pTau rel

0.926 0.978

0.865

0.676 0.801

0.582

0.991 1.000

1.000

0.922 0.913

0.801

0.893 1.000

0.975*

0.970 0.999

0.999

Ab1-42/ pTau rel

pTau/ pTau rel

0.949

0.678

1.000

0.846

1.000

1.000

P673

of single markers as well as biomarker ratios was determined for each pairwise comparison of different dementia groups and controls. To evaluate the diagnostic power of pTau rel in the routine AD biomarker panel, the single (routine) marker with the highest AUC value was compared with that of pTau rel. Additionally, the (routine) biomarker ratio with the highest AUC value was compared with its equivalent using pTau rel. An overview of the results is listed in Table 1. Conclusions: The diagnostic performance of pTau rel for differential dementia diagnosis (comparing AD, FTLD, CJD patients and healthy controls) is not better than the diagnostic performance of the routine AD CSF biomarkers.

P2-154

EFFECTS OF AEROBIC-STRENGTH TRAINING ON SELECTED MOLECULAR TARGETS IN CEREBROSPINAL FLUID OF SENIORS WITH MILD COGNITIVE IMPAIRMENT

Barbara Ukropcova1,2, Lucia Slobodova2,3, Matej Vajda4, Patrik Krumpolec3, Veronika Tirpakova4, Silvia Vallova1,2, Katarina Ondicova2,3, Stanislav Sutovsky5, Chia-Liang Tsai6, MingChyi Pai7, Peter Turcani5, Peter Valkovic5, Milan Sedliak4, Jozef Ukropec3, 1 Institute of Experimental Endocrinology, Biomedical Research Center, SAS, Bratislava, Slovakia; 2Faculty of Medicine, Comenius University, Bratislava, Slovakia; 3Institute of Experimental Endocrinology, Biomedical Research Center, SAS, Bratislava, Slovakia; 4Faculty of Physical Education and Sports, Comenius University, Bratislava, Slovakia; 5Faculty of Medicine, Comenius University & University Hospital Bratislava, Bratislava, Slovakia; 6Institute of Physical Education, Health and Leisure Studies, National Cheng Kung University, Tainan, Taiwan; 7National Cheng Kung University Hospital, Tainan, Taiwan. Contact e-mail: barbara. [email protected] Background: Regular physical exercise has been shown to

improve cognitive functions in individuals with mild cognitive impairment (MCI). To assess effects of exercise on specific markers in cerebrospinal fluid (CSF), we have performed lumbar puncture in 9 seniors (age 66,362,5y) with (n¼4/0 F/M) or without (n¼2/3 F/M) MCI, before and after 3-month training. Methods: Intervention: aerobic-strength training (1h 3x/week, 60-70% VO2max or 60-70% 1RM, resp., increasing work load with respect to increasing fitness/strength). Phenotyping before/after training included cognitive tests (Adenbrooke’s test, ACE-R; computerized MemTrax), body composition (bioimpedance), physical fitness (VO2max: Rockport test), physical activity monitoring (accelerometers & Baecke questionnaire), muscle strength measurement (dynamometry) and functional motor tests. Lumbar puncture by atraumatic technique was performed by experienced neurologist. CSF samples were used to determine amyloid-b1-42(Ab1-42), total tau & phosphorylated tau (T-tau&P-tau181P) (a single-analyte ELISA kits), lactate (colorimetric assay) and a group of selected exercise-regulated microRNAs (qPCR). Results: We have previously shown that 3month aerobic-strength training improved cognitive & motor functions, physical fitness and muscle strength in control and MCI individuals. Here we report no effects of training on CSF Ab1-42, T-tau & P-tau181P(p>0.05). However, lactate was increased in CSF of all MCI individuals, compared to controls (+15,8%, p<0.05) and did not change with training in neither group. Interestingly, one out of 5 selected microRNAs was increased in CSF of MCI seniors as compared to controls

P674

Poster Presentations: Monday, July 25, 2016

(w170%, p<0.05). Furthemore, physical training resulted in a decrease of this microRNA specifically in MCI group (>4fold, p<0.05) with a similar trend in controls. In the pooled analysis (before & after training, n¼18), CSF expression of this exercise-regulated microRNA correlated negatively with a cognitive test score (r¼-49, p¼0.038), muscle mass (r¼-0.48, p<0.05), physical fitness (r¼-0.64, p¼0.003), speed of walking (r¼-0.72, p¼0.001) and a leisure time index (r¼-0.47, p¼0.049) and positively with MemTrax reaction time (r¼76, p¼0.004) and time of the chair stand-up test (r¼0.744, p<0.001). Conclusions: Three-months aerobic-strength training specifically modified selected biomolecules in cerebrospinal fluid of seniors with/without MCI. These observations need to be confirmed in larger cohorts and a putative role of exerciseregulated microRNA(s) in beneficial response to exercise remains to be determined.

P2-155

DEVELOPMENT AND VALIDATION OF A SALIVARY TAU BIOMARKER IN ALZHEIMER’S DISEASE

Heather Pekeles1,2, Hamid Y. Qureshi2, Hemant K. Paudel1,2, Hyman Schipper1,2,3, Mervyn Gornitsky1,2,3, Howard Chertkow1,2,3, 1 McGill University, Montreal, QC, Canada; 2Lady Davis Institute, Montreal, QC, Canada; 3Jewish General Hospital, Montreal, QC, Canada. Contact e-mail: [email protected] Background: Total tau (t-tau) and phosphorylated tau (p-tau)

are abnormally elevated in the brain and cerebrospinal fluid (CSF) of Alzheimer’s disease (AD) patients. Tau has also been found to be present in salivary gland tissue (Conrad et al. 2002) and saliva (Shi et al. 2011). Non-invasive and inexpensive biomarkers for AD are needed, and one possible source is saliva. Methods: Using unstimulated saliva and western blot analysis, we quantified the p-tau/t-tau ratio at different phosphorylation sites. We determined phosphorylation level at serine 404 (S404), serine 396 (S396) and threonine 181 (T181) as well as combined phosphorylation of serine 400, serine 403, and serine 404 (S400,S403,S404). We collected saliva from 41 AD subjects, diagnosed by clinicians at the Montreal Jewish General Hospital, and 44 cognitively normal elderly controls (NEC), aged 60 and over with a score of 25 or greater on the Montreal Cognitive Assessment (MoCA). As well, we collected saliva from 55 subjects with mild cognitive impairment (MCI) to determine its usefulness as an early biomarker. We also collected from 76 young controls to explore possible age-related differences. Finally, we collected from 16 frontotemporal dementia (FTD) patients, a condition where some subjects have tau pathology, and from 12 subjects with non-tau related neurological conditions, in order to better determine specificity of the test. Results: We found that the p-tau/t-tau levels were significantly elevated in AD subjects compared to NEC at phosphorylation sites S396 and S404, ps<0.05. There was large variation in ptau/t-tau levels in each diagnostic group. Conclusions: The large variation in levels of AD subjects suggests this test may not be useful as a diagnostic biomarker. However, our results demonstrate a significant difference in AD patients compared to cognitively healthy elderly subjects at two phosphorylation sites. Our work adds to the limited work on peripheral markers of AD. Future work should explore other phosphorylation sites, and should further investigate the mechanism for increased tau and p-tau in saliva.

P2-156

ELUCIDATION OF NOVEL AB EPITOPE TARGETS ALLOWS FOR AN ANTIBODY-SPECIFIC TARGETING OF EARLY AB OLIGOMERIZATION

Adrien W. Schmid, Ecole Polytechnique Federale de Lausanne (EPFL), Lausanne, Switzerland. Contact e-mail: [email protected] Background: Ab oligomers account for the decline in memory associated with dementia and therefore represent an appealing diagnostic and therapeutic target for Alzheimer’s disease (AD). In order to specifically target Ab oligomerization in the early stages of AD pathogenesis, it is important to develop accurate and sensitive assays to identify key molecular triggers of Ab aggregation before the development of clinical symptoms. Methods: High resolution( LC-MS/MS) and quantitative selected reaction monitoring (SRM) mass spectrometry (MS) analysis of human control and AD patient brain tissue and CSF samples (n¼15). Human brain tissue and CSF samples were processed by immunoprecipitation (IP) followed by immoblotting and / or LC-MS/MS analysis. The analytical advantages of the recently developed neoepitope antibodies were compared with two commercially available antibodies (6E10 & 4G8). Results: In this study we present our recent discovery studies on the key molecular events associated with early Ab peptide aggregation. Our findings have enabled us to design and develop novel antiAb antibodies which allow a specific targeting of Ab oligomers. The use of targeted and quantitative MS revealed a site-specific Ab autocleavage during the early phase of aggregation, producing a typical Ab fragment signature. We have identified truncated Ab isoforms with highly increased aggregation properties, which form stable oligomeric complexes with full-length Ab peptide. We further show that the use of novel anti-Ab antibodies raised against these Ab isoforms allows for specific monitoring and targeting Ab oligomers. Screening of human post-mortem brain tissue and CSF samples from AD patients and control subjects revealed that these molecular changes of Ab peptide are a highly relevant feature found in AD patients. Conclusions: Our work highlights the necessity for identification of key molecular mechanisms associated with Ab peptide misfolding that may predict the pathogenesis of cognitive impairment. The use of strong, prodromal biomarkers of dementia will allow identifying individuals with mild cognitive impairment (MCI) who may benefit from early therapeutic intervention.

P2-157

IS THIS THE MANHATTAN PLOT FOR ALZHEIMER’S?

Markku Kurkinen, Wayne State University School of Medicine, Detroit, MI, USA. Contact e-mail: [email protected] Background: Alzheimer dementia [OMIM 104300] is diagnosed by slowly progressing and irreversible memory and mind problems, followed by remarkable behavioural and personality changes, and loss of self. Methods: GWAS (genomewide association study) of Alzheimer case genomes has identified several nucleotide changes associated with increased dementia risk. Results: However, none of them compares to the nucleotides in a 250kb DNA on chromosome 19q13.2, which has several genes including the polymorphic APOE gene. Only the APOE4 gene makes a major difference, so that people with E4/E4 have 10-fold increased Alzheimer