National Geographic

When You’re A Naked Mole Rat, Why Stop At One Weapon Against Aging?

In June I wrote about the amazing longevity of naked mole rats. These rodents can live for thirty years, whereas their mice cousins can only live two years. One secret to their longevity may be the fact that they’ve never been documented with cancer. As I wrote back in June,  scientists at the University of Rochester found  a gooey protein in the tissues of the rodents that prevents cells from multiplying out of control.

But naked mole rats do more than just fight cancer. In addition to avoiding tumors, they also resist the overall decline seen in other aging mammals. A new study from the same Rochester team may reveal how they ward off aging: they’re very careful about making proteins.

Like other animals, naked mole rats carry DNA that encodes thousands of genes. To make a protein, the mole rat’s cells make a single-stranded version of the corresponding gene (called messenger RNA), which is then grabbed by a cellular factory called a ribosome, which is made up of RNA molecules and proteins. The ribosome reads the messenger RNA and uses the genetic code to pick out building blocks to attach to a growing protein.

If the ribosome picks the wrong building block, a protein may end up with a defective shape and can’t do its job properly. A big part of getting old is the accumulation of these defective proteins. Our cells end up getting worse and worse at all the things they excelled at when we were young. Collagen no longer stretches in our skin; our digestive enzymes no longer break down nutrients as efficiently as before. A number of studies have hinted that we can extend our healthy lifespans by boosting our ability to repair defective proteins.

The Rochester team took a look at how naked mole rats build proteins. They discovered something odd about their ribosomes. All living things use pretty much the same set of RNA molecules in this factory. One of these molecules is called 28S. Naked mole rats have a mutation to the gene for 28S RNA. Instead of producing a single RNA molecule, they break it in two.

To see if two 28S molecules worked differently than just one, the researchers compared how the naked mole rats make proteins to the process in mice. They engineered a gene and inserted it into both species. If a cell made an error at one site in the protein, the protein would give off a flash of light. A cell that always built perfect proteins would stay dark. A sloppy cell would glow.

The scientists found that the naked mole rat cells were much darker than those of mice. They built the engineered protein far more accurately, in other words. Naked mole rats, the scientists found, made anywhere from four to ten times fewer mistakes. Yet the naked mole rats can make their proteins as quickly as the sloppier mice.

The scientists were unable to directly examine the 28S RNA fragments in action, so they can’t say for sure that splitting 28S in two is the reason for the accuracy of naked mole rat proteins. Still, the results offer an intriguing hint that this ugly creature has more than one secret to long life. Whether we can borrow that secret is hardly clear. I for one wouldn’t volunteer to have my ribosomes shattered.

(Reference:  Jorge Azpurua et al.“Naked mole-rat has increased translational fidelity compared with the mouse, as well as a unique 28S ribosomal RNA cleavage.” PNAS 2013)

There are 23 Comments. Add Yours.

  1. Tonia
    September 30, 2013

    You have some typos.

    “The scientists found that that naked mole rat cells were much darker than those of mice. They far built the protein far more accurately, in other words.”

    How did these get past the editor? Very unprofessional.

    [CZ: Thanks for pointing those out. As a blogger, I'm my own editor.]

  2. Tuan Nguyen
    September 30, 2013

    I believe that Cynthia Kenyon has convincingly demonstrated that such a repair mechanism is already present in human. We all have a fountain of youth gene that is down regulated by insulin, the hormone of growth. When insulin is low, cell repair and maintenance kick in and become more efficient, the immune system is revved up, eg aging is slowed down. And how do you get low insulin? Via a ketogenic diet, which is also effective against cancer and dementia, both a result of cell aging and senescence. So my question is: why are we still spending zillions of dollars searching for a cure for cancer and Alzheimer when the bleeding obvious solution is staring us in the face?

  3. Neill Kramer
    October 1, 2013

    Ever since your article about the metabolism of bats I keep thinking that mitochondria is the secret weapon to a more highly optimized life.

  4. Michael
    October 1, 2013

    Really should be investigated for the possibility of creating an anti cancer treatment. Worthwhile research.

  5. David
    October 1, 2013

    That is one ugly rat.

  6. Not A Grammar Nazi Pete
    October 1, 2013

    Awesome article, it always amazes me that people always look over the point of something when there is grammatical errors lol… Ignore Tonia, he/she is just upset cause recently he/she found out what a loser he/she is

  7. Mike B
    October 1, 2013

    So, after 30 years what exactly “kills” a naked mole rat. Drive by shooting? Suicide? The will to live? A “Logans Run” scenario?

  8. Adil Asgher
    October 1, 2013

    “Naked mole rats, the scientists found, made anywhere from four to ten times fewer mistakes.” What are the numbers/units you are referring to that the Naked mole rats’ are 4-10 times fewer?

  9. Ben
    October 1, 2013

    Fascinating. Today I can say I learned something substantial and fundamental: that aging is the accumulation of mistakes made during gene replication. (Maybe I should have known that, but a light went off today when I read this article.) Thanks for the piece!

  10. Nestor
    October 1, 2013

    We do live rather longer than 30 years so perhaps our bodies already know those tricks

  11. Curt Hays
    October 1, 2013

    Very unprofessional…Haha! Thanks for writing such a fascinating article. If it wasn’t for the typos, I’d tell other people to read it.

    Just kidding. I’m following you on Twitter now.

  12. eddie
    October 1, 2013

    And makes you look great too.

  13. Roy Marvelous
    October 1, 2013

    If I looked like that, I don’t think I’d want to live that long….

  14. August Pamplona
    October 1, 2013

    I know it doesn’t add much to the conversation but damn, that’s amazing! I mean that’s the major RNA component of the large ribosomal subunit, isn’t it?

  15. Richard
    October 1, 2013

    @Tuan Nguyen

    You shouldn’t be advocating a ketogenic diet as a magic bullet to cure ageing, cancer and dementia when it comes with so many associated risks. When used by medical professionals it is controlled and monitored. Not to mention side effects can be managed.

    Like any medical therapy found to have other beneficial properties, it’s not something that should be being tried by those unaware of the risks.

    • Tuan Nguyen
      October 1, 2013

      @ Richard
      Please specify the risks associated with a ketogenic diet? Because I cannot find any significant ones anywhere in the published materials.

      You are of course aware of Thomas Seyfried’s “Cancer as a Metabolic Disease: On the Origin, Management, and Prevention of Cancer”.

      Of course there’s NO money to be made through a ketogenic diet. Anybody can do it. What a bummer eh?

  16. gs
    October 1, 2013

    This is why we should fund more research by Aubrey De Gray’s SENS project and also the Mprize projects (both tax deductible scientific research charities in the US….also DARPA is doing some interesting research too….we need to fund these programs with the money saved by waging less wars.

  17. Billy Joe
    October 1, 2013

    “That is one ugly rat”

    He speaks well of you, though!

  18. Ali Abbas
    October 2, 2013

    Article is good but I couldn’t find that grammatical mistakes :P I Guess it’s been updated! Appreciated! :)

  19. Rudi
    October 2, 2013

    Interesting findings. Though one should be careful in jumping the gun. As with any good research, this opens up more questions. For example, would 4-10 times more protein errors actually be a bad thing in naked mole rats? In other words, we are not entirely sure yet as to what lead to the aging in these animals.

  20. Margaret
    October 2, 2013

    Was it a “gooey protein”? I thought it was hyaluronan, which is a glycosaminoglycan, with no protein component.
    Correct me if I’m wrong.

  21. safia
    October 4, 2013

    wonderful information. this article has inspired me to dig more about the possibility of treating cancers in the future.maybe i will invent a new drug that stops mutation of the cell thus cancer would be just a thing of the past hopefully…….

  22. Jane Peters
    October 7, 2013

    Maybe humans could live longer too if everyone of us stopped smoking and eating foods with herbicides, pesticides, fungicides and other toxic substances on them.

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