Enzyme Found To Help Formation of New Axons

Greg George writes "Researchers at Emory University and Georgia Institute of Technology have announced that they have found an enzyme that helps nerves to grow in areas damaged after trauma. In typical injuries, scar tissue forms around the damage point and the body removes the tissue so that new muscle and nerves can regrow in the damaged area. In spinal cord injuries, scar tissue forms and that is the end of the story. Special chemicals form that stop the body's cells from moving in and removing the scar tissue and then allowing the healing process to start. Studies have been done attempting to bypass the scar tissue, but none has been successful in large-scale repair of injured muscle and nerves in the spinal column. The researchers for this paper have found that sugar proteins near the damage point stop the healing and that an enzyme can be used to break down these proteins so that the body can then begin repairs. The enzyme, chondroitinase ABC (chABC), is sensitive to heat, and breaks down quickly in a human body. To stop that process they found that by replacing the ABC with another sugar called trehalose, they were able to stabilize the ABC, allowing it to break down scar tissue over a large area. The gel formed by these sugars is stable for up to six weeks in the bodies of test animals, allowing the research team to inject growth factors that increased the healing, to the point that the animals started to use their limbs again. The work is still in the beginning stages." Reuters reporting adds a few more details: "...many other approaches will be needed to repair spinal cord injuries in humans, including controlling inflammation, which can cause additional injury, stimulating nerve fiber growth, and getting nerves to reconnect and communicate with the brain."

Comments

I can finally be free..

[Xerfas]

Researchers at Emory University and Georgia Institute of Technology have announced that they have found an enzyme that helps nerves to grow in areas damaged after trauma.

I can finally be free of the mental image of goatse!

Re:I can finally be free..

[physburn]

For that you need to destroy brain cells, not grow them. I suggest vodka until you fall over.

---

Humour Feed @ Feed Distiller

tl;dr

[BadAnalogyGuy]

Sometimes I read a summary here on Slashdot and wonder why the submitter left out crucial pieces of information.

Then there are summaries like this which throw everything and the kitchen sink in. What's worse, there is only one submitted link, so it's not like there are multiple sources gathered together making this summary long, it's just a lazy submitter cutting and pasting from the article.

Growing axons is a nice step, but Christopher Reeves is dead already. It'll be hard to get another celebrity to put their weight behind this kind of research.

Re:tl;dr

[SydShamino]

It'll be hard to get another celebrity to put their weight behind this kind of research

You are incorrect.

I spoke recently with Doctor Charlotte Smith of the Spinal Cord Injury Recovery Center at Brackenridge Hospital in Austin, Texas, who has seen regrowth of spinal nerve cells in patients undergoing umbilical cord stem cell treatment combined with computer-controlled direct stimulation of detached nerves.

Her research continues to attract funding, but it began from a rehabilitation center significantly funded by former and current professional football players. Consider someone like Kevin Everett, who, after 15 minutes as a quadriplegic ended his football career, has devoted his time and effort toward raising money for spinal cord research.

While the brutality of professional football injuries can be tragic, it does instill in many players a need to campaign for a cure. These are the celebrities that step up and put their weight behind the research.

How do we fasttrack this research?

[jameskojiro]

Sounds like this is somethign we should be dumping more "Stimulus Money" into so that we can cure people with traumatic nerve damage, this would save countless millions or billions as people confined to wheelchairs would not need so much fiscal support compared to non paralyzed folks.

If they need human volunteers for trials I don't think they would have any trouble finding any....

Ok, but why...?

[mea37]

"In spinal cord injuries, scar tissue forms and that is the end of the story. Special chemicals form that stop the body's cells from moving in and removing the scar tissue and then allowing the healing process to start."

I'm assuming this is one of those "the body does this beacuse its better in normal circumstances, but in the case of severe trauma it's not so good" kind of things... but can anyone clarify why the body's normal healing process is blocked for spinal injuries?

Re:Ok, but why...?

[BadAnalogyGuy]

It's an evolutionary advantage for the entire herd when a single injured member is incapacitated, thereby allowing predators to focus on the injured member instead of healthy members of the herd.

So by basically erasing all hope for recovery for the spinal injury victim, Evolution has enabled the non-injured humans a means of escape from lions, tigers, and bears.

Since we live in modern society, it's uncommon to see this kind of pursuit. However, evolutionarily speaking, the movement to cities and civilization is a pretty recent phenomenon. Until that fateful event, humans were preyed upon by many other wild animals.

Re:Ok, but why...?

[vertinox]

It's an evolutionary advantage for the entire herd when a single injured member is incapacitated, thereby allowing predators to focus on the injured member instead of healthy members of the herd.

Not exactly... Its more evolutionary advantageous to the predator that it eats the weakest members of a herd group rather than having to fight the strongest or all of them at once.

As a weakened or injured member does not actually promote or demote the passing on of genes of other members of the herd as predators aren't as able or willing to catch the healthy ones anyways for the risk reward offer.

Ergo, the predator is the one that passes on its genes and techniques to its offspring because it is more likely to survive that way where the heard isn't simply evolved to sacrifice its members.

For example, Elephants will defend their young, injured, elderly, and even corpses from predators and scavengers even though they could spend resources elsewhere. That is more or less an evolved "denial of resources" to its natural predators which in turn makes less of them.

As far as why animals can't regenerate nerve endings, it has to do more or less that most animals that are attacked and injured don't live long enough anyways after the fact to pass on their genes because of persistence of the predator or infection.

Re:Ok, but why...?

[clone53421]

Elephants will defend their young, injured, elderly, and even corpses from predators and scavengers

They must taste really good. If I tasted really good, I wouldn't want anybody finding out either.

Oh shit—

Re:Ok, but why...?

[mcgrew]

can anyone clarify why the body's normal healing process is blocked for spinal injuries?

Because until recent times, and with any wild animal, a spinal injury is a death sentence. No way to evolve past it.

Re:Ok, but why...?

[radtea]

It's an evolutionary advantage for the entire herd when a single injured member is incapacitated, thereby allowing predators to focus on the injured member instead of healthy members of the herd.

Kin selection, which is what you are invoking here, should generally be the last place you look for evolutionary explanations. It can be important, but it's a second-order effect and is easily incorrectly invoked, as you are doing here.

Kin selection would operate in this case only because "the herd" consists of close relatives of the injured animal. If you consider a kin-group consisting of (injured animal with major spinal cord damage)+(really close relatives), your argument requires that the advantage to (really close relatives) in terms of increased numbers of offspring due to preferential predation on (injured animal with major spinal cord damage) is bigger than the disadvantage to the entire group when one of its members is no longer available for breeding.

The problem is this: it makes no difference to the group which animal gets eaten. If the injured animal could heal, then it would be an un-injured animal, presumably capable of reproducing. So unless you are going to argue that spinal cord injuries that heal are necessarily going to reduce the reproductive fitness of the individual, your argument makes no sense: the question raised was "Why don't they heal?" and your answer amounts to the unsubstantiated claim that "healed animals will have radically lower reproductive fitness."

It is true that injured animals will have radically lowered reproductive fitness, but we're asking, "Why don't they heal given that healed animals would have the same reproductive fitness as any other?"

Saying, "Injured animals have lower reproductive fitness and therefore it is an advantage to their kin group to have them eaten rather than their more fit kin" does nothing to explain why injured animals don't heal and therefore become as reproductively fit as their uninjured kin.

And kin selection leaves out all kinds of solitary animals, like bears, say, that so far as I know have the same problem with non-healing spinal cords as humans.

My personal bet on the evolutionary mechanism behind this is that non-lethal severe spinal cord injuries are sufficiently rare that there just isn't that much evolutionary pressure on healing them, and that scaring, which is a generic mechanism in warm-blooded animals that suppresses regeneration of all kinds, is such a coarse filter that it happened to turn off regeneration in the spine entirely.

In general, cold blooded animals do not scar, but do have some capacity to regenerate, sometimes entire limbs. This works for them because they can effectively shut down for a long periods of time while the healing process takes place. Warm blooded animals have to keep their body temperature up, which means they can't afford the long down-times of cold-bloods, so they have been selected for rapid "field dressing" in the form of scaring, and what we know about the gene pathways suggests that that interferes with regeneration. Lack of regeneration in the spinal nerves could easily be a consequence of that, and like I said: there's probably not much evolutionary pressure on it because how often does an animal get a non-lethal injury that cuts the spinal cord? We see humans with spinal injuries surviving because of medical intervention, but things mentioned in the summary like inflammation, are major killers in untreated spinal injury. That's just speculation, though, and as I hope I've shown above, it's very easy to screw up when trying to reason informally about this stuff.

Re:Ok, but why...?

[PitaBred]

Pot. Kettle.

Evolution doesn't produce perfect. It produces good enough. If it's good enough for our species to survive that a spinal injury cannot be healed, then there is no pressure to select for that trait. It doesn't enable reproduction at a rate higher than other people. If spinal injuries were common in our species, then there would be pressure. But they aren't, and if they happen you're usually dead anyway, so it isn't a trait that's selected for. Any one person or group who might produce this enzyme doesn't have enough of a better chance to reproduce because of it that it would become common.

Very limited potential

[140Mandak262Jamuna]

Yeah, yeah, yeah, it is a great breakthrough and it provides a new understanding and all that. But fundamentally these kind of enzymes and stuff coax the body into healing itself and so their effectiveness is quite limited. Better to go with bio-interfaced electronics. I once saw a documentary where this guy was almost totally burnt in a volcano. The scientists were able to replace all the lost limbs with mechanical, cornea and trachea with mechanical components, a black helmet and a black cape and he was almost as good as new. Cool thing was, though he was modded so heavily, he still had enough mitachloreans and retained almost all the Force he had to begin with. Amazing. I tell you.

You can't.

[tjstork]

Everyone seems to think that we can just throw more money at this or that disease and we would have a cure, but, we can't. There are only so many scientists, so much equipment today. If you threw more money at it, you'd probably just be buying the original researchers PostDocs a new car apiece, and maybe funding a Phd or two. If you want more scientists today, start by changing culture 20 years ago.

Re:You can't.

[clone53421]

If you want more scientists today, start by changing culture 20 years ago.

I'll get right on that as soon as all the money I've been dumping into time-travel research pays off.

Re:You can't.

[interkin3tic]

If you threw more money at it, you'd probably just be buying the original researchers PostDocs a new car apiece, and maybe funding a Phd or two. If you want more scientists today, start by changing culture 20 years ago.

Bull shit.

There are plenty of projects that would yield good results out there, and people to do them, but the money is lacking, so said projects get put on the backburner or scaled down. There may be a point at which dumping more money on research will just be wasted, but we are nowhere close to that point. I look at progenitor cells that eventually make up the spinal cord, we use microscopes that cost a lot of money per hour. Really limits the experiments I can do. Extra money would mean I could look at those cells with different markers, under different conditions. Every time I run one of those experiments, I learn more than I was expecting to about how an embryo makes it's spinal cord. Some of those lessons may be useful to treating diseases of the spinal cord or how to repair injured spinal cords.

To be fair though, some stimulus money has been given out, with some unusual strings attached. And also to be fair, putting "stimulus" money into basic research doesn't seem like a very good way to stimulate the economy in the short term. It's a good long-term investment that does need more money, but stimulus, no. Bottom line though, research could definitely use more money, we're far from saturation, and it would definitely be a better investment than giving it to some fucking bank CEO.

Re:You can't.

[Anonymous Coward]

This is just not true. Many researchers at universities are having to cut back severally both in personnel and equipment. They are also are being turned down for tenure which encourages them leaving for the privet sector which does more short-term research. While some stimulus money did go to NIH which immediately approved a bunch of grants, the times have been lean for more than 2 years for researchers. All this did was at best bring many labs back to a functional level, not up to maximum research capacity.

As for the PostDoc cars comment, grad students generally get a stipend of around $22-24K and PostDocs make more but still generally under $45K. And the grants don't boost their stipend, which is a preset amount. Rather, it goes into grant money which is monitored and expenses must be justified. So no, it would go directly into research.

Yes, throwing money at a problem wont necessarily solve it faster, but in the case of many labs it would in fact allow for faster progress.

Disclaimer: I work at a university in a biology lab as a research technician.

Re:You can't.

[Hatta]

There are many more researchers than there are funds. If anything, we produce too many grad students for the available positions. More money would employ more researchers, and more science would get done.

Re:You can't.

[Andy Dodd]

As long as there are graduate students in school worried about whether they'll have a job when they graduate, I have a feeling that providing additional funding for research is not anywhere near a "point of diminishing returns" scenario.

Also, you comment "there's only so much equipment today" - More/better equipment leads to scientists becoming more productive, in addition to the fact that I don't think there's a shortage of scientists to take advantage of additional funding, the lead time on equipment is far less than the lead time for new scientists (time to go through school as a scientist vs. choosing another career path as an undergraduate). The gating factor towards equipment availability for scientists is NOT availability of equipment to purchase, but of money to purchase that equipment with.

Re:You can't.

[amplt1337]

you'd probably just be buying the original researchers PostDocs a new car apiece

Actually, that sounds like a pretty good way to encourage more people to study science. Then we'll at least change culture today and have a bunch more scientists 20 years from now.

Re:You can't.

[kaiser423]

It is good stimulus funding. You say that you can spend it RIGHT NOW to get more equipment time, etc. That provides an immediate economic benefit right now. It's "shovel ready".

More time on the equipment means that the owner pays it off faster, making it cheaper in the future, and making them more likely to invest in new machinery, both increasing the infrastructure in the field and increasing capability, as the newer scopes probably have better features.

I actually had a hard time thinking about a better use of stimulus funding: It can be spent right now, it will be utilized to create more infrastructure/capability in a growing/emerging field, it will increase our knowledge in that field, and have long term implications for the industrial base in that field thus serving as an excellent long-term investment also. Not to mention the new treatments, etc that can be created further stimulating the economy.

Link to Scientific Article

[structural_biologist]

Here's the actual research paper being cited:

Lee H, McKeon RJ, Bellamkonda RV. Sustained delivery of thermostabilized chABC enhances axonal sprouting and functional recovery after spina chord injury. Proc. Natl. Acad. Sci. USA 2009. doi: 10.1073/pnas.0905437106.

The summary is slightly incorrect in saying that this group discovered that the chondroitinase enzyme can aid in recovery after spinal cord injury (this has been known for a while, see Bradbury et al. (2002) Nature 416:636–640, whom the authors cite). The authors contribution is to engineer a version of the enzyme that is more stable and works better than the natural version of the enzyme. Because the enzyme is more stable than the natural enzyme, the authors can implant a hydrogel at the site of injury that slowly releases the enzyme over the course of two weeks. The authors show that this sustained delivery improves neuron regrowth and the locomotor function of the injured animals compared to just a single dose of the natural enzyme (which degrades relatively quickly after injection).

Re:Evolutionary Advantage?

[roguetrick]

The Central Nervous system has its own types of cells called glial cells that are very specialized. These cells provide everything from an immune response to creating a framework for growing neurons. This is advantageous because one of the first structures to develop in an embryo is the central nervous system and having an enclosed environment keeps the CNS from having to deal with a lot of the problems that the other environments of the body have to deal with. It is really a pretty amazing system, you should check it out.

Re:Evolutionary Advantage?

[roguetrick]

Yes, it completely divorces the immune system from the central nervous system. Capillaries go into the CNS, but you don't have things like white blood cells in there. This prevents a few things, normal body cells from destroying CNS cells for example. An immune cell destroying nerve cells would be very bad.

Re: group selection

[mr_overalls]

This would make sense if genes operated at the group level. They do not. Groups selection is pretty much discredited as a mechanism of evolutionary change. http://en.wikipedia.org/wiki/Group_selection

Re:Sounds so simple, almost as simple as a do-re-m

[grantek]

No, you have to:
sudo chABC -R /lib/modules/*
sudo mkinitnerves --all --spinal
then reboot

This is why neuroscience just isn't ready for the masses