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Biotech Science

Scientists Demonstrate Mammalian Tissue Regeneration 260

Posted by Soulskill
from the wolverine-explained dept.
telomerewhythere writes "A quest that began over a decade ago with a chance observation has reached a milestone: the identification of a gene that may regulate regeneration in mammals. The absence of this single gene, called p21, confers a healing potential in mice long thought to have been lost through evolution and reserved for creatures like flatworms, sponges, and some species of salamander. 'Unlike typical mammals, which heal wounds by forming a scar, these mice begin by forming a blastema, a structure associated with rapid cell growth and de-differentiation as seen in amphibians. According to the Wistar researchers, the loss of p21 causes the cells of these mice to behave more like embryonic stem cells than adult mammalian cells, and their findings provide solid evidence to link tissue regeneration to the control of cell division. "Much like a newt that has lost a limb, these mice will replace missing or damaged tissue with healthy tissue that lacks any sign of scarring," said the project's lead scientist.' Here is the academic paper for those with PNAS access."
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Scientists Demonstrate Mammalian Tissue Regeneration

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  • So (Score:5, Funny)

    by jimbobborg (128330) on Wednesday March 17, 2010 @11:04AM (#31508764)

    We can all be Wolverine now? Cool!

    • Re:So (Score:5, Funny)

      by Monkeedude1212 (1560403) on Wednesday March 17, 2010 @11:07AM (#31508794) Journal

      Minus the Claws. And the Adamantite interior. And the Rugged good looks - in your case, anyways.

    • by Exitar (809068)

      Nope. Rat-Man.

    • Actually, my first thought was that if I can regenerate, then all I'm missing is a TARDIS.

      brb, off to find some TARDIS coral so I can grow my own TARDIS.

    • We can all be Wolverine now? Cool!

      More like Deadpool. [wikipedia.org]

      However, his healing factor results in massive scar tissue causing his appearance to be severely disfigured. An unanticipated side effect of the therapy was a rapid acceleration of cancerous tumors as well, causing them to quickly spread across his entire body as soon as his powers fully activated.

      Except without the funny one liners, awesome assasin skills, teleporter, or probably the rivalry with wolverine. I suppose you could wear the costume though and get in a fight with a real wolverine.

      • Re: (Score:3, Informative)

        by jimbobborg (128330)

        However, his healing factor results in massive scar tissue causing his appearance to be severely disfigured.

        No scarring with this stuff.

  • by Culture20 (968837) on Wednesday March 17, 2010 @11:07AM (#31508792)
    Now I can finally start my restaurant (which specializes in mouse-tail delicacies) without PETA breathing down my neck. "Look: it's growing back!" Mouse-tail soup anyone?
  • by tedgyz (515156) * on Wednesday March 17, 2010 @11:14AM (#31508876) Homepage

    You know this discussion will degenerate into how this can be applied to growing a longer penis.

    • Re: (Score:3, Funny)

      by protodevilin (1304731)
      Then I hope it doesn't involve having to amputate the penis first.
      • by hanabal (717731)

        if it did thought, would you. I mean if you could grow any penis size you wanted but you had to cut your original one off to get it, would you. Bonus points if you weren't allowed anaesthesia as that affects the regrowth.

    • by JavaBear (9872) *

      You know this discussion will degenerate into how this can be applied to growing a longer penis.

      No, but spammers are sure to find a way to try and sell that point

    • by geekoid (135745)

      If by 'larger' you mean 'second', then yes.

    • by Chris Burke (6130)

      *Jamaican^W WoW troll voice*

      They say that when you cut off an extremity it regenerates a little bigger.

      Don't believe it.

  • by fuzzyfuzzyfungus (1223518) on Wednesday March 17, 2010 @11:19AM (#31508960) Journal
    What the side effects are. One would(perhaps naively) assume that regeneration is an obvious survival advantage, and that losing regenerative capabilities would be a handicap. That being so, one would tend to suspect that an anti-regeneration gene would be fairly strongly selected against. Since this gene is, in fact, rampant in mammals, one is led to the suspicion that there must be some sort of upside.

    Is it something more or less irrelevant to modern humans(at least those wealthy enough to ever be genetically engineered), something like "without any sort of medical care, most serious injuries were fatal before regeneration could occur, so the extra energy costs weren't worth it", or is it some kicker of the "Well, without a whole bunch of other adaptations possessed by certain amphibians and creepy-crawlies, you'll 'regenerate' yourself entirely full of tumors by age 20." flavor?
    • by ColdWetDog (752185) on Wednesday March 17, 2010 @11:24AM (#31509026) Homepage
      Think of it this way: MOST of the time, your body tries mightily to STOP things from growing - those are typically cancers (uncontrolled cell division). It may have been easier in the evolutionary sense to shut down regeneration than to deal with it's consequences.

      Remember, you are not a newt.
      • by AioKits (1235070) on Wednesday March 17, 2010 @11:33AM (#31509150)

        Remember, you are not a newt.

        I got better...

        • Remember, you are not a newt.

          I got better...

          And it only took a couple hundred million years, doctor Nature!

      • Re: (Score:3, Interesting)

        by pesho (843750)
        I second this. p21 is what you call a 'tumor suppressor' gene. Without p21 it is significantly easier to get cancer. It would matter less to mice, because of their short lifespan and different DNA damage repair strategy (fix aggressively active genes, don't care much about the rest). For humans with life span ten times longer compared to mice, this is real deal breaker. These mice also appear to have some sort of autoimmune disease.
      • by bazorg (911295)
        well, I AM a a newt, you insensitive clod!
      • by Cormacus (976625)

        Think of it this way: MOST of the time, your body tries mightily to STOP things from growing - those are typically cancers (uncontrolled cell division). It may have been easier in the evolutionary sense to shut down regeneration than to deal with it's consequences.

        Agreed, but this line from the article is very iteresting:

        Heber-Katz said. "In these mice without p21, we do see the expected increase in DNA damage, but surprisingly no increase in cancer has been reported." In fact, the researchers saw an increase in apoptosis in MRL mice -- also known as programmed cell death -- the cell's self-destruct mechanism that is often switched on when DNA has been damaged

        So I guess the question is whether programmed cell death has certain other consequences.

      • by delt0r (999393)
        It has been suggested that the "scar" response is prevents regeneration, and is "fitter" because infection is less likely.
    • by bcmm (768152) on Wednesday March 17, 2010 @11:26AM (#31509070)
      Scarring is much faster, and probably carries a lower risk of infection for creatures that don't have access to medical care.
    • by Spatial (1235392)

      One would(perhaps naively) assume that regeneration is an obvious survival advantage, and that losing regenerative capabilities would be a handicap. That being so, one would tend to suspect that an anti-regeneration gene would be fairly strongly selected against. Since this gene is, in fact, rampant in mammals, one is led to the suspicion that there must be some sort of upside.

      We can't synthesise vitamin C either, but there's no benefit to that. Almost all other animals can synthesise it, but we get scurvy and die unless we ingest it.

      If it doesn't kill you before you can reproduce, and it doesn't make you infertile, it can be passed on. We lack that ability because one of our ancestors lacked it, but survived and reproduced regardless.

      Because of that low standard for selection, it's relatively easy for a trait to be irrelevant to the selection process, good or bad.

      • Re: (Score:3, Interesting)

        by SydShamino (547793)

        If on the other hand you make the presumption that an ancestor species had it, then you might wonder why we lost that ability. Sure, it might not affect survivability before age of reproduction either way. But then why did only those without the ability survive?

        It's a reasonable question when looked at from that angle.

    • Re: (Score:3, Insightful)

      by Scrameustache (459504)

      What the side effects are. One would(perhaps naively) assume that regeneration is an obvious survival advantage, and that losing regenerative capabilities would be a handicap. That being so, one would tend to suspect that an anti-regeneration gene would be fairly strongly selected against. Since this gene is, in fact, rampant in mammals, one is led to the suspicion that there must be some sort of upside.
      Is it something more or less irrelevant to modern humans(at least those wealthy enough to ever be genetically engineered), something like "without any sort of medical care, most serious injuries were fatal before regeneration could occur, so the extra energy costs weren't worth it", or is it some kicker of the "Well, without a whole bunch of other adaptations possessed by certain amphibians and creepy-crawlies, you'll 'regenerate' yourself entirely full of tumors by age 20." flavor?

      Well, FTFA: "In normal cells, p21 acts like a brake to block cell cycle progression in the event of DNA damage, preventing the cells from dividing and potentially becoming cancerous," Heber-Katz said. "In these mice without p21, we do see the expected increase in DNA damage, but surprisingly no increase in cancer has been reported."
      In fact, the researchers saw an increase in apoptosis in MRL mice -- also known as programmed cell death -- the cell's self-destruct mechanism that is often switched on when DNA

    • by AceJohnny (253840)

      you'll 'regenerate' yourself entirely full of tumors by age 20.

      The article states: "In these mice without p21, we do see the expected increase in DNA damage, but surprisingly no increase in cancer has been reported."

      Also, I suggest other /.ers read the article. It is high quality, not a random blog post.

  • Which way first? (Score:4, Insightful)

    by spaceman375 (780812) on Wednesday March 17, 2010 @11:19AM (#31508962)

    The next step is to make some p21 specific RNA interference molecules and shut it down in an adult, non-regenerative mouse. Then clip its ear and see what happens.
    Since it also increases apoptosis, would this make a good diet pill?

    • Re: (Score:3, Interesting)

      by Deosyne (92713)

      Screw that. 6.5+ billion people on this planet, many with a propensity toward cutting, scarring, beating, or even killing themselves, and we can't find just one who will volunteer to have this done so that we can see what will happen in a human? Christ, I could find a couple of dozen people in the next hour who would be willing to go on a suicide mission to Mars. Doing this kind of thing to an unwilling victim is straight-up evil, but finding volunteers really can't be that hard. Let's just answer the real

  • Pythonic... (Score:2, Redundant)

    "She turned me into a newt!"... "I regenerated!".
  • Isn't this the backstory to the Lizard? He tries to regrow his arm using amphibian DNA, and whoops - he turns into a Lizard.

    Hm, it sounds really stupid now that I've typed it out.
    • Re: (Score:2, Informative)

      by serialband (447336)

      Isn't this the backstory to the Lizard? He tries to regrow his arm using amphibian DNA, and whoops - he turns into a Lizard.

      Hm, it sounds really stupid now that I've typed it out.

      Lizards are reptiles.

  • This is, obviously, the holy grail for many injuries and holds out immense hope for amputees etc. etc. There's one thing about it that has me concerned. Darwinism is cruel. It causes the weak to fall by the wayside of evolution and the strong to perpetuate the best of the species. Nature does things for a reason. The question in the back of my mind is: if we fool with this, what are the underlying natural reasons for the gene to be turned off? We aught to be taking a very close look at the consequences of t
    • Which is why we do tests on lab animals instead of injecting random people with completely untested gene therapies.

      But don't tell PETA. They don't want you to do lab tests on animals, but they also don't want to volunteer themselves as human guinea pigs.

    • by compro01 (777531) on Wednesday March 17, 2010 @11:43AM (#31509286)

      I can think of a couple reasons why this feature may have been dropped. nutrition (regrowing something is a hell of a lot more resource intensive than just closing the hole) and infection prevention (just closing the hole is a lot faster than regrowing something, so less chance of it getting infected). Both of these were relevant considerations very recently and evolution is pretty slow.

      • Re: (Score:3, Interesting)

        by DrMaurer (64120)

        I think you have an interesting point here on the resource requirements of regeneration. Part of the obesity problem is that our bodies evolved to store whatever they couldn't use right now for later, so it stands to reason that such things were "turned off" for efficiency's sake. We didn't necessarily evolve in a land of plenty

        As for infection rates, I would like to see that study done, too...

        • Re: (Score:3, Interesting)

          by ArsenneLupin (766289)

          Part of the obesity problem ...

          So this gene will be a solution to that problem as well:

          You're fat? No problem, just lop off a leg, it'll regrow, and in the process consume the excess belly...

    • the underlying natural reasons for the gene to be turned off? We aught to be taking a very close look at the consequences of turning on this gene

      Other way around: The absence of this single gene, called p21, confers a healing potential in mice

    • Re: (Score:2, Insightful)

      by Anonymous Coward

      Sure anyone with even a vague knowledge of evolution and basic highschool genetics will worry, but as long as they make vague promises like bigger dicks, hair regrowth and weight loss pills, they won't have any problems.

    • Re: (Score:3, Interesting)

      by zwei2stein (782480)

      Any form of health care is dangerous this way.

      Consider this: we can (and do) save many children with birth defects, often we are succesfull enough so that they can leard normal life (and even be oblivious to any issues). Problem is that some of theese defects are hereditary. Guess what? Next generation is worse off as far as ratio of defects is concerned.

      We obviously will never do "sparta" thing and kill of children society finds undesirable. Nor will anyone with genetic defect be prevented from having chil

    • by lawpoop (604919) on Wednesday March 17, 2010 @12:10PM (#31509710) Homepage Journal

      Darwinism is cruel... Nature does things for a reason.

      Narture wants to be anthropomorphized ;)

      It nature is so cruel and barbaric, then for what reason did it evolve human beings who feel sympathy, empathy, are able to learn, and practice healing arts?

    • Nature does things for a reason

      Actually, no it doesn't.

    • The only reason that mammals with an active p21 gene and the inability to regenerate tissue continued on and p21 suppressed mammals did not is because chicks dig scars. No perfectly healthy scarless male is going to attract a hot chick who is only interested in the dummy injury prone type.
  • Somewhat not being able to regenerate (or something deeply related with that) gave us an evolutionary advantage. Is pretty tempting to just make pills to turn that off, but what will be the cost? Don't think that you will fall into not being able to get older or make new memories, but still stinks to too good to be true.
  • ...in practice, do we have the technology to knock this gene out in humans? That's the key thing. Either you have to engineer every human to have the gene before birth, or you have to do a live fix. And a live fix has all sorts of complications.

    Of course, I'm completely ignoring potential side effects. This is best if you imagine a drug for it being advertised: "Regrowitol may cause side effects including cancer, accessory limbs, mutation into evil lizard creature..."

    We're living in the future, sure. But we

  • What's the downside? (Score:5, Informative)

    by Biotech9 (704202) on Wednesday March 17, 2010 @11:36AM (#31509204) Homepage

    A lot of people are asking why evolution has taken away our regenerative capacities, and are guessing what the downside of this regeneration is.

    P21 is involved with anti-cancer. It arrests the cell cycle when DNA damage occurs, allowing the damage to be repaired (so mistakes are not carried forward into new generations). Or if the damage is too severe, the cell is made senescent (they lose the ability to reproduce and instead lead out a gentle retirement, performing their normal job until they just die of old age)

    P21 knockout mice show a lot of carcinomas and P21 is also up-regulated by and works to remedy excessive oxidative stress. It's very unlikely this research is going to lead to a pill that knocks out P21 and lets us grow limbs back. It will only lead to a greater understanding of how our pathways work.

    • by Cormacus (976625)
      So there was an interesting line in the article:

      Heber-Katz said. "In these mice without p21, we do see the expected increase in DNA damage, but surprisingly no increase in cancer has been reported." In fact, the researchers saw an increase in apoptosis in MRL mice -- also known as programmed cell death -- the cell's self-destruct mechanism that is often switched on when DNA has been damaged

      What are the consequences of apoptosis vs senescence?

    • by Chris Burke (6130)

      Or if the damage is too severe, the cell is made senescent (they lose the ability to reproduce and instead lead out a gentle retirement, performing their normal job until they just die of old age)

      I just heard one of my P21-arrested liver cells audibly scoff at that "gentle retirement" bit. :)

  • My guess is that while not having this gene results in wonderous regenerative abilities, it'll also increase your chances of developing cancer before the age of 20 by a bajillionfold. Not a problem for mice, but certainly a problem for men.

  • by calibre-not-output (1736770) on Wednesday March 17, 2010 @12:20PM (#31509868) Homepage
    But this still makes me giddy for the future of Medicine.
  • Promissing but... (Score:3, Informative)

    by Corson (746347) on Wednesday March 17, 2010 @12:21PM (#31509880)
    It is unlikely that a process so complex as mammalian tissue regeneration be controlled by a single gene. Moreover, p21 mutations have been associated with cancers. Which brings forth another question: why is it that only "lower" organisms (and mammalian fetuses) are capable of scar-less tissue regeneration? The answer is yet to be discovered but it is very likely that evolution had to stroke a balance between cancer control and tissue regeneration. It won't be easy to figure out "the way back" to regeneration, or even to avoid the risks of such a path.
  • What is the reason that life forms without that ability won the evolutionary war in the first place?
    What bad could come from that ability? Side-effects?
    Because I really can’t see any downsides.

    Anyone here who is a bit more of an expert than the random coward? ;)

  • by zero_out (1705074) on Wednesday March 17, 2010 @12:40PM (#31510264)

    Here is the academic paper for those with PNAS access.

    I have access to a PNAS. Sometimes I let my wife have access to it, too.

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