19. ageing biology 5 Flashcards
why are studies on people that live for a very long time hard? (3)
they are hard to organise, expensive and run over many years
how many people live over 100?
1 in 5000
how many people live over 110?
1 in 5 million
what is presumed about people that live over 110?
there is something special about their genome and cellular biology, as it is unlikely that they have been protected from environmental stresses during this time
what percentage of how long we live is down to genetics, and what does this increase to after the age of 85?
20-30%
40%
GWAS of people that are very old are difficult due to what factor?
lack of control groups
what can be done to overcome this GWAS difficulty? (even if it is not ideal)
looking at the offspring of those that live long and those that don’t and comparing their genomes to look for genetic components involved
which gender live longer and why is this becoming less apart?
women on average live longer, but now we are post-industrial and men have less risky jobs
what was seen in the serum of offspring of centenarians? and what polymorphism was observed?
35% higher serum IGF1
a slight loss of function of IGFR1 which results in reduced phosphorylation of Akt and dampening of metabolism
what was seen in some Japanese semisupercentenarians? and what did this suggest?
one form of INSR (insulin receptor)
this suggests that there is something about insulin signalling and nutrient sensing that is crucial for lifespan regulation
what genes that are related to insulin signalling have intronic SNPs been identified in that are associated with long life?
AKT1 and FOXO3A
what are the limitations of lots of these studies?
they identify genes associated with people that live longer than others but don’t necessarily determine how this affects molecular biology of their cells
long lived males in Hawaii had SNP associated with what gene?
FOXO3
what was also interesting about these long lived Hawaiian men? and what did this suggest?
- they had less cancer and cardiovascular disease, they felt healthier and had good physical and cognitive function
- this suggests that they have more robust stress responses
particular alleles of what genes have been linked with long life? (5) and what does this suggest?
ApoA, LMNA, WNR, SOD1 and SOD2
this suggests that ageing is not down to one gene, it is down to a combination of genes