Gene that allows planarian regeneration identified

http://www.theregister.co.uk/2010/04/26/decap_growback_gene/

Now we just need memory backup - and worm DNA

By Lewis Page

Posted in Biology, 26th April 2010 11:35 GMT

British boffins say they have identified the key "smed-prop" gene which allows Planarian flatworms to regenerate any part of their body following an injury - even their brains. The discovery is seen as a step towards regeneration therapy for humans in future.

Top bio-boffin Dr Aziz Aboobaker and grad student Daniel Felix, who carried out the new research, say that the discovery of "smed-prep" unlocks the mechanisms by which the hard-to-kill Planarians grow new muscle, gut and brain cells from stem-cells which are present even in adults. Even more importantly, it seems that the information contained in smed-prep also makes the new cells appear in the right place and organise themselves into working structures - as opposed to nonfunctional blobs of protoplasm.
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Understanding the process completely in worms, according to Aboobaker, is a necessary prerequisite for making it happen in humans. Another cunning worm trick he wants to get to the bottom of is the method by which the Planarians cope with rogue stem-cells producing defective cells - regeneration gone wrong, after all, in basically cancer.

The doc suggests that it may be possible in future to simply grow new organs and limbs for injuried or sick humans - even, perhaps, to repair their damaged brain in situ. This would be preferable to removing a duff brain and growing a new one, as happens when a planarian worm's head is cut off.

"If we know what is happening when tissues are regenerated under normal circumstances, we can begin to formulate how to replace damaged and diseased organs, tissues and cells in an organised and safe way following an injury caused by trauma or disease. This would be desirable for treating Alzheimer's disease, for example," says Aboobaker.

"With this knowledge we can also assess the consequences of what happens when stem cells go wrong during the normal processes of renewal — for example in the blood cell system where rogue stem cells can result in Leukaemia," he adds.

Felix, who actually did the worm-chopping during the experimental programme, said:

"It has been a really exciting project and I feel very lucky".

Felix and Aboobaker's paper, The TALE Class Homeobox Gene Smed-prep Defines the Anterior Compartment for Head Regeneration, is available here free, courtesy of the journal PLoS Genetics. ®

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http://www.theregister.co.uk/2009/03/24/newt_regeneration_for_humans/

DARPA at phase 2 on human 'regeneration' tech

By Lewis Page

Posted in Biology, 24th March 2009 15:39 GMT

Famed US military mad-professor bureau DARPA has inked a second deal with Massachusetts researchers to develop ways of "regenerating" human body tissues cut, shot or blown off in combat. The new biotech therapies would employ the same methods used by newts in growing replacement limbs.

News of the award comes courtesy of the Worcester Polytechnic Institute (WPI), which announced the $570,000 agreement between DARPA and WPI-spawned company CellThera yesterday. CellThera is expected to work with the university's bioengineering department in delivering Phase II of DARPA's "restorative injury repair" programme.
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DARPA seems to be looking for full-on, science-fiction level regen therapies here. According to the military wild-science boffins:

The vision is to fully restore the function of complex tissue (muscle, nerves, skin, etc) after traumatic injury on the battlefield... with true “wound healing” by regeneration of fully differentiated, functional tissue.

The program will achieve its goals by... processes of morphogenesis leading to anatomic and functional restoration [which] will culminate in the restoration of a functional multi-tissue structure in a mammal.

Under Phase I, CellThera and WPI bioengineers "succeeded in reprogramming mouse and human skin cells to act more like stem cells, able to form the early structures needed to begin the process of re-growing lost tissues" - a process described by DARPA as "generating a blastema in an otherwise non-regenerating animal".

A blastema is the boffinry term for the clump of special progenitor cells which appears at injury sites in creatures naturally able to regenerate themselves, such as newts or salamanders. Another name, according to the Encyclopaedia Britannica, is "regeneration bud". When you cut off a salamander's leg, for instance, a blastema appears at the stump and then grows into a new leg with muscles, nerves etc all complete.

It seems then that the Massachusetts boffins have already produced basic regen buds, potentially capable of growing into new working body parts - at least for mice.

"We are very pleased to be moving into the next phase of this work," said Raymond Page, WPI biotech prof.

We might all wish the prof luck and look forward to the day when limbs, buttocks etc cruelly snatched away before their time by the violence of the enemy, drunk drivers or horrific household accidents can simply be regrown. Or indeed to the day when we might, like Zaphod Beeblebrox, choose to sprout an extra arm - perhaps for critical multitasking applications involving drinks or complicated game peripherals.

The only people genuinely likely to be upset by this prospect would seem to be the rival DARPA-funded boffins engaged in developing the rocketfuelled, steam-powered cybernetic arm. The spraycan wound-spackle guys might still be OK, as presumably severed limbs etc would still need to be stabilised while regrowth took place. ®