Transcript Genetic and molecular determinants of human ageing and

Why do we age so differently?
Genetic and Molecular Determinants
of Human Ageing and Longevity
- DNA repair, pro- and antioxidant
and insulin/IGF-1 signaling pathways
M.Sc. Mette Sørensen
Ph.D. student at SDU
Supervisors:
Associate Professor Lene Christiansen
Professor Kaare Christensen
Associate Professor Tinna Stevnsner
Professor Vilhelm A. Bohr
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DANISH AGING RESEARCH CENTER
www.sdu.dk/darc
Funded by:
VELUX FONDEN
Presentation Outline
 Background
 Genetic influence on ageing and longevity
 Candidate biological pathways
 Single nucleotide polymorphisms – SNPs
 The purposes and the status of the project
 Subproject 1 – Association study of genetic variations
in candidate genes/pathways with longevity and aging
→ Golden Gate chip and more.
 Subproject 2 – Functional studies of genetic variation
 Pilot study of rs4880
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DANISH AGING RESEARCH CENTER
www.sdu.dk/darc
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Genetic Influence on Ageing
and Longevity
 Genetic factors influence age-related diseases and age-related
physical and cognitive functions
 Genetic factors contribute to the variation in lifespan by
approximately 25%. The contribution is minimal before age 60
years and most profound from 85 years and onwards
 Candidate biological pathways for ageing and longevity:
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Lipid metabolism
Immune response
Cell cycle regulation
Insulin metabolism
Antioxidants
DNA repair
.......
- DANISH AGING RESEARCH CENTER
www.sdu.dk/darc
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Single Nucleotide Polymorphisms
(SNPs)
Person A
Person B
. . . GAA GGA CGA GAA . . .
. . . GAA GGA TGA GAA . . .
Person A
Person B
. . . Glu Ala Arg Glu . . .
. . . Glu Ala Stop
Consequences; amino acid substitution, Splice site etc.
 Estimate: 3 -15 • 106 SNPs in the human genome (1/2001/1000 nucleotides)
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DANISH AGING RESEARCH CENTER
www.sdu.dk/darc
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The Purpose of Subproject 1
Investigate the association of genetic variation in candidate
genes composing DNA repair, pro/antioxidant and
insulin/IGF-1 signaling pathways with human longevity and
ageing (e.g. disease prevalence, physical and cognitive abilities)
 Longitudinal study: 1651 individuals of The Danish 1905
birth cohort
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Follow-up time: 10 years, age at death 92-100+
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Interviews and assessments of functional and cognitive abilities
 Cross sectional study: 800 individuals of the Study of Middle
Aged Danish Twins, age 42-65
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Interviews and assessments of functional and cognitive abilities
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DANISH AGING RESEARCH CENTER
www.sdu.dk/darc
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Status of Subproject 1
 Literature search → choosing 168 candidate genes
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Association studies of longevity and/or age-related diseases
Relevant for premature aging syndromes
Animal research (e.g. knock outs)
Additional genes to cover the pathways
 Database search → choosing 1536 SNPs
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Association candidate SNPs
Functional SNPs (non-synonymous, splice site etc.)
Tagging SNPs to cover the genetic variation
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Linkage disequilibrium (the non-random association of alleles at
two or more loci).
 Purification of 2400 DNA samples for Golden Gate chip
(1536 SNPs * 2400 individuals)
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DANISH AGING RESEARCH CENTER
www.sdu.dk/darc
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 Genotyping (Aros Biotechnology), finish in May 2009
 Data Analysis is started – Genome Studio, Plink
 Next:
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Data Analysis
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Additional genotyping (Taqman, SNPlex methods):
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In depth of possible Golden Gate chip findings
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Additional SNPs (impossible via Golden Gate chip)
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DANISH AGING RESEARCH CENTER
www.sdu.dk/darc
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The Purpose of Subproject 2
 Investigate the functional consequences of SNPs
 Findings via the Golden Gate Chip
 Recombinant variant RecQ helicases; genes are on
Golden Gate chip, made in corroboration with the
Aarhus group
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DANISH AGING RESEARCH CENTER
www.sdu.dk/darc
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Pilot study of the SOD2-rs4880 SNP and
longevity in the 1905 cohort,
Background:
 Epidemiology:
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rs4880 has been shown to be associated the several age-related
diseases (e.g. cardiomyopathy, atherosclerosis and Alzheimer's).
 Animal research:
SOD2 knock outs → Decreased life span (D. melanogaster) or
neonatal lethality (m. musculus)
 Over expression → Increased life span (D. melanogaster and m.
musculus)
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 Molecular biology:
rs4880 in the mitochondrial targeting sequence → less transport
of T variant precursor protein into the mitochondrial matrix
 4 x more processed MnSOD / MnSOD activity in C variant cells
than in T cells
 60% lower O2.- levels in C cells than in T cells
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DANISH AGING RESEARCH CENTER
www.sdu.dk/darc
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Pilot study of the SOD2-rs4880 SNP and
longevity in the 1905 cohort,
(one of) the result(s):
 Increased survival of SOD2-rs4880 CC/CT individuals:
 Mortality risk (CC/CT vs. TT): 0.91, P = 0.002
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DANISH AGING RESEARCH CENTER
www.sdu.dk/darc
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Published in Spring 2009:
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DANISH AGING RESEARCH CENTER
www.sdu.dk/darc
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