Scientists at the University of Liverpool have identified high levels
of a number of genes in the naked mole-rat that may suggest why they
live longer than other rodents and demonstrate resistance to age-related
diseases.
The Liverpool team has recently generated the first whole-genome
sequencing data of the naked mole-rat - a rodent that lives for more
than 30 years and is resistant to cancer - to understand its longevity
and resistance to disease. Scientists, in collaboration with Harvard
University, have now compared the levels of its genes with genes in wild
mice to investigate what makes naked mole-rats different to other
rodents.
They found that genes associated with mitochondria, that provide
energy to cells, and genes that affect respiration and the decisions
cells make, are expressed at unusually high levels in the naked mole-rat
compared to the same genes in wild mice. In animals and humans these
genes are thought to play a role in influencing and adapting to cell
damage, which is thought to be one of the significant causes of ageing.
Naked mole-rats, however, also have increased levels of oxidative
stress, which is an imbalance in reactive molecules containing oxygen.
This can lead to mutations in the cells and the growth of cancerous
tumours. To date, cancer has not been detected in the naked mole-rat,
but these new findings suggest that the rodent has mechanisms of
regulating gene responses to limit the potential negative impact of
oxidative stress on cells. The research will help scientists focus on
particular areas of the genome to further understanding into how the
body ages.
Dr Joao Pedro Magalhaes, from the University's Institute of
Integrative Biology, said: "The naked mole-rat is native to the deserts
of East Africa and has unique physical traits that allow it to survive
in harsh environments for many years. It has a lack of pain sensation
in its skin and has a low metabolic rate that allows it to live
underground with limited oxygen supply.
"It has been of interest to scientists for some time and we hope
that by studying its genome it will help us understand the mechanisms of
ageing and how the body protects itself from disease.
"These findings add further evidence to research that suggests genes
responsible for mitochondria and oxireduction are associated with the
ageing processes. It also provides some clues as to how naked mole-rats
protect themselves against high levels of oxidative stress. The high
levels of genes connected to energy production and cell decision-making
systems may help in creating an intracellular environment that prevents
cancer and other age-related diseases.
"This work provides candidate genes for specifying resistance to
ageing and cancer that we can build on in future studies. The next
stage of the research will be to observe what happens to the cells if
gene levels change from high to low and vice-versa."
