A new article published in Physiological Reviews compared some remarkable similarities and differences between naked mole rats and humans. Both are relatively long-lived, highly social and have low natural selection pressures. But, this is about all they have in common. While humans are prone to developing age-related cancer, diabetes, heart disease and dementias, naked mole rats are rather resistant to these diseases. Instead, naked mole rats appear to maintain a youthful state throughout their long lives of 30+ years, compared to a mere 3 years for a mouse. To top it off, they do not develop age-related wrinkles and they can continue to procreate throughout their lifespan.
Naked mole rats are not without complications associated with aging as they can show signs of muscle wasting and reduced fat under the skin. The underground life and highly social nature of these animals offers them the protection of a large number of subordinates, which reduces mortality rates and natural selection pressures.
For many mammals oxidative stress increases with age and further promotes aging by damaging cells. As naked mole rats are resistant to oxidative stress, antioxidants are thought to help slow down aging.
The authors argue that humans have likewise maintained prolonged youth compared to the great apes. To maintain this youth, other structures and functions have been delayed or underdeveloped. For example, like naked mole rats, humans have sacrificed hair, large body size and the muscle strength found in the great apes. Age-related mortality rates are also low for young humans. In contrast, signs of age-related mortality are evident earlier in the development of chimpanzees. Moreover, the human brain (like a naked mole rat) exhibits delayed expression of certain genes and has prolonged growth allowing for complex problem solving.
VP Skulachev, S Holtze, MY Vyssokikh, LE Bakeeva, MV Skulachev, AV Markov, TB Hildebrandt, VA Sadovnichii. Neoteny, Prolongation of Youth: From Naked Mole Rats to “Naked Apes” (Humans). Physiological Reviews. 97(2): 699-720, 2017. DOI: 10.1152/physrev.00040.2015
Categories: Comparative Physiology