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Cardiff Neurosciences Centre (CNC)

Cardiff Neurosciences Centre (CNC). Alzheimer’s Disease Network. Cardiff Neurosciences Centre Manager www.cardiff.ac.uk/cnc Dr Vanessa Davies cnc@cardiff.ac.uk. Aims of AD Network. Scope research interests Facilitate communication between research groups: meetings, website

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Cardiff Neurosciences Centre (CNC)

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  1. Cardiff Neurosciences Centre(CNC) Alzheimer’s Disease Network Cardiff Neurosciences Centre Manager www.cardiff.ac.uk/cnc Dr Vanessa Davies cnc@cardiff.ac.uk

  2. Aims of AD Network • Scope research interests • Facilitate communication between research groups: meetings, website • Establish strengths, weaknesses and obstacles to success • Act strategically

  3. AD Research NetworkThemes • Complex Genetics • Nutrition • Neuropsychology and Imaging • Epidemiology: Caerphilly Cohort • Clinical Trials • Animal Models • Stem Cells • Therapeutic Antibodies

  4. Dementia • 700,000 people have dementia in the UK • 1 million by 2025 • 1.7 million by 2050 - 150% up • Dementia: main cause of burden in later life • Dementia - 11% of years with disability • Cardiovascular disease 5.4% • Cancer 2.4%

  5. Large Scale Genetic Association Studies in Alzheimer’s Disease Julie Williams

  6. Why find genes • Alzheimer’s disease is heritable- 79% • Pinpoint biological pathways contributing to disease development • Test for gene x environment relationships • Use knowledge to develop new treatments, preventative therapies • To predict disease susceptibility

  7. Alzheimer’s Disease:Causal and Susceptibility Genes PS1: > 150 PS2: < 20 APP: < 20 PS2 APOE APP PS1

  8. APOE • Acts to reduce age at which disease starts • Effect observed from 40 diminishes after 70 • Neither necessary nor sufficient to cause AD • Association stronger in Japanese, weaker in African American & Hispanic samples • Stronger in females • Accounts for 15% genetic variance E3 E3 Reduced risk of AD E3 E2 Increased risk of AD E4 E4

  9. Large Scale Genetic Association Studies in Alzheimer’s Disease

  10. Disease susceptibility allele ↑Markers tested = ↓Power ↑ Power = ↑Sample size

  11. MRC Genetic Resource for Late Onset Alzheimer’s Disease

  12. 1400 AD cases • 1400 matched controls • Validated case interview- 92%ppv • Controls screened • Longitudinal follow-up: 600 • Breadth phenotypic data: AAO, ROD, symptoms • MRI imaging: 150 • Brain banking ▲

  13. Identifying Alzheimer’s Disease Susceptibility Genes Through Genetic Association 17353 markers 1800 AD 2000 controls Hum. Mol. Genet., 2007

  14. Genes showing most evidence of association with Alzheimer’s disease

  15. Galanin-like Peptide Precursor-GALP,Tyrosine Kinase, Non-receptor – TNK1, Phosphoenolpyruvate Carboxykinase 1- PCK1 • Galanin modulates cholinergic pathways & effects TAU phosphorylation-tangles • TNK1- protein trafficking & signal transduction • PCK1-risk factor for Type 2 Diabetes

  16. Possible AD Susceptibility Genes • ALZGENE (Bertram et al, NAT. GENET., 39, 2007) • ACE, GAPDHS, CHRNB2, CST3,ESR1, IDE, MTHFR, NCSTN, PRNP, PSEN1, TF, TFAM and TNF • DAPK1 (Li et al, Hum. Mol. Genet., 17, 2006), RPS3A/SORBS1 (Grupe et al, 78, 2006), NEDD9 (Hum.Mol.Genet.,17, 2008)

  17. 131 new susceptibility variants for complex traits identified in the last year

  18. Current Genome Wide Association Studies (GWAS) of AD • Coon et al, Reiman et al (2007): GAB2 (APOE e4+) • Li et al (2007): GOLPH2 • Beecham et al (2007): AMIGO2 & SENP1 • All find association with APOE locus • No genome wide significant gene • All AD case samples between 500-750 (discovery phase)

  19. Pooled GWA Study of Late-onset Alzheimer’s Disease Bonferroni corrected p-value 9.1 x 10-8 DNA Pools 1,082 LOAD cases and 1,239controls (x replicates) Illumina Beadchip 550,000 SNPs genotyped 109 top hits genotyped individually (+70% sig p<0.05) Funded by The Alzheimer’s Research Trust

  20. POOLED GWAS – INDIVIDUAL GENOTYPING RESULTS

  21. Pooled GWAS – Lecithin Retinol Acyltransferase(LRAT) LD Structure * *

  22. POOLED GWAS – Additional genotyping of Lecithin Retinol Acyltransferase(LRAT) TAG SNPs * * Mutations in LRAT cause severe early-onset retinal dystrophy Plays prominent role in Vitamin A (retinoid) cascade Retinoid levels in plasma, serum and brain lowered in LOAD

  23. Powerful Genome-wide Association Screen For AD Susceptibility Genes 19,000+ Subjects 610,000 markers Stage 1: 4,283 AD & 8995 CON; Top Hits: 2278 AD & 3,797 CON

  24. Genome Wide Association Study of Alzheimer’s Disease

  25. Secondary Analysis • APOE, age at onset, rate of decline • Relationship with symptoms: psychosis, depression, • Copy number variation • TOP hits: functional analysis - animal models • Biological pathways • Meta-analyses (+ imputation): other AD GWAS GWAS of neurodegenerative disorders GWAS vascular diseases GWAS of psychosis, depression

  26. AD Pathways • Amyloid β clearance • Oxidative stress • Tau • Insulin signalling • Apoptosis • Cholesterol • 1178 AD pathway genes included to date

  27. Conclusions • AD susceptibility & disease modifying genes remain to be identified. • Powerful GWA studies are likely to succeed in discovering new susceptibility genes. • New AD genes on the horizon!

  28. Cardiff AD Genetics Group School of Medicine, Cardiff University Julie Williams Michael J. Owen Michael O’Donovan Richard Abraham Paul Hollingworth Peter Holmans Angharad Morgan Rebecca Simms Funded by Medical Research Council Alzheimer’s Research Trust, Wellcome Trust, Alzheimer’s Society &Welsh Assembly Government. Valentina Moskvina Marian Hamshere Ivan Nikolov Leslie Jones Kimberley Dowzell George Kirov Alexandra Stretton Ricardo Segurado Gary Hill williamsj@cardiff.ac.uk

  29. Cardiff University Julie Williams, Mike Owen Richard Abraham, Paul Hollingworth, Angharad Morgan, Peter Holmans, Mick O’Donovan Institute of Psychiatry, London Simon Lovestone Cambridge University Carol Brayne, David Rubinsztein Trinity College, Dublin Brian Lawlor, Mike Gill University of Nottingham Kevin Morgan University of Manchester David Mann University of Southampton Clive Holmes University of Bristol Pat Kehoe Queen University, Belfast Peter Passmore David Craig OPTIMA Study, Oxford University David Smith Donald Lehhman LASER- AD, University College London Livingston, Hugh Gurling, Katona and Nick Bass University College London John Hardy, Martin Rosser, Nick Fox, Simon Mead Washington University, St Louis, US Alison Goate Mayo Clinic, Florida, US Steve Younkin NIH, Bethesda, Washington, US

  30. ... N-TF K T E E 665 T I INS P F T 117 116 T S Y 115 E I 120 D E L 113 APP T Q V E 123 G K 670 M 671 D T A 1 E D F 673 R H b secretase 677 D S V K G G R Y Q T E R Y T Y V H S H N K G A A Q K F L 105 V F L F D T V F S A 692 H a secretase E A A V 693 W V S D N 694 V S S E 405 184 L P I V Y D E T K A G G S L N K I L K Y T W K Lumen G A N I I 135 A A T I T I I Y 409 G A A F C A I T G 394 246 237 410 V I L V F V V F W L M A L L M 392 V S V 139 235 178 A V 96 A I L I F V V S 177 S M G L L I F V 390 233 250 Y 94 A L L G I V F M F 175 A I L V I V C W 231 143 174 I 92 40 S N L I G V V L F 173 I I S F L V L T 229 D 418 A M M L C V G 713 V G 146 206 171 89 T I S 384 T Y L P V 714 256 420 G 147 V I L D S 42 V T V 715 226 169 I L L L L G g secretase I Y 716 F L 209 A V L M L L I V 717 I K 167 A I Q L L V M 260 T 424 166 V 84 Q S V V L I W L 222 261 G 165 83 L L A L A I 378 V R 213 V 153 262 426 82 Y I 377 M 154 F L 723 H DEL Cytosol H R K E 163 C H 263 K K DEL F INS K L E I W ... Y K 219 K P 264 K I INS M R K P 269 R V P K L A C-TF L P G G A 79 271 267 217 431 C K Y D Presenilin 1 V G 272 L E E Y 273 P W K G N T M I 274 R A I 278 T E 467 434 A E 280 L L Q P A 284 A Y Q V V Y M E T L T Q 435 R D V E A L E 285 E L E S D E E S F V P L G 436 282 N L D 286 I S 290 N Q P I F S G E H S S Q A K F Y S I N N 439 A K S E Q V 318 S R R S 365 P A T T E R L R R S R G H P L E P S C-TF L N D G L F E E N S Q G Q H Q D L D E V M V T Q A F F V R A 35 P Y A H E L S T N S V R Q N N R D 26 N 29 28 27 R 358 Q F E D S V A N E E L D T S P D N-TF Y D R INS T G 354 M S G R F Q H S P E E G A L W E H A T E L M A Q P S P 1 L R D S Y F Q N

  31. Genetic Testing • Mutation detection should be concentrated in clinical genetics laboratories offering a national service. • Suitable candidates for mutation detection would need to meet the minimum criteria of: • i) Positive family history (more than two affected members in two generations) • ii) Diagnosed Alzheimer’s disease • iii) Family counselling regarding the implications of mutation screening, with particular emphasis being given to the fact that in some families mutations may not be found • iv) Appropriate consent and assent • Genetic testing for prediction should always follow the detection of a mutation in an affected family member and accord with the guidelines established for Huntington’s disease (Simpson and Harding, 1993). • International Journal of Geriatric Psychiatry • 14, 789-791 (1999)

  32. Alzheimer’s Disease • Common: 62% of dementia 1% <65yrs, 40% >90yrs • Episodic memory loss followed by gradual cognitive decline • Key biological markers: plaques & tangles • Genetically complex: many genes involved

  33. RPS3A Homologue, SORBS1 & DAPK • RPS3A hom- function unknown • RPS3A acts with Bcl-2 to prevent apoptosis • SORBS1 involved in insulin signalling & upregulated in hippocampus AD brains • DAPK affects apoptosis

  34. Glyceraldehyde-3-phosphate dehydrogenase: GAPD • Key enzyme in cellular energy processes • Neuronal apoptosis • Binds APP & Aβ • GAPD mediated apoptosis inhibited by tacrine & donepezil • GAPD activity higher in AD brains and over-expressed in Down’s syndrome brains

  35. APOE 112 158 ApoE-2 GAC GTG TGC TGC CGC CTG……….CTG CAG AAG TGC CTG GCA ApoE-3 GAC GTG TGC TGC CGC CTG……….CTG CAG AAG CGC CTG GCA ApoE-4 GAC GTG CGC CGC CGC CTG……….CTG CAG AAG CGC CTG GCA 1 2 3 4 +300 -491 A/T -419 T/C -219 G/T +1 +113 C/G TATA BOX EXON1 GC BOX N.S.E URE 3 URE 1 DRE

  36. Effects of ApoE4 Generated by CNS Astrocytes and Neurons Huang et al, 2004

  37. APOE • APOE may affect one or a number of processes implicated in late-onset AD pathogenesis: • Aβ processing • Tangle formation • Neurite outgrowth & branching • Apoptosis

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