Futurismic

Exciting results from the world of biology, with implications for human medicine: researchers looking at the limb regeneration process in salamanders have discovered that it works in a different way to what they thought previously. [image by jurvetson]

Rather than having their cellular clocks fully reset and reverting to an embryonic state, cells in the salamanders’ stumps became slightly less mature versions of the cells they’d been before. The findings could inspire research into human tissue regeneration.

“The cells don’t have to step as far back as we thought they had to, in order to regenerate a complicated thing like a limb,” said study co-author Elly Tanaka, a Max Planck Institute cell biologist. “There’s a higher chance that human or mammalian cells can be induced into doing the same thing.”

[...]

They found that salamander regeneration begins when a clump of cells called a blastema forms at the tip of a lost limb. From the blastema come skin, muscle, bone, blood vessels and neurons, ultimately growing into a limb virtually identical to the old one.

Researchers, many of whom hoped their findings could someday be used to heal people, hypothesized that as cells joined blastemas, they “de-differentiated” and became pluripotent — able to become any type of tissue. Embryonic stem cells are also pluripotent, as are cells that have been genetically reprogrammed through a process called induced pluripotency.

Such cells have raised hopes of replacing lost or diseased tissue. They’re also difficult to control and prone to turning cancerous. These problems may well be the inevitable growing pains of early-stage research, but could also represent more fundamental limits in cellular plasticity.

If Tanaka’s right that blastema cells don’t become pluripotent, then the findings raise another possibility — not just for salamanders, but for people. Rather than pushing cellular limits, perhaps researchers could work within nature’s parameters.

Another step towards transhuman immortality, perhaps? It’s fun seeing such science fictional subjects in ‘regular’ news venues, if only to watch journalists asking the sort of questions science fiction has always hinged on – like Khaled Diab at The Guardian, for example, trying to imagine what the world would be like if Aubrey De Grey is right about the immortality singularity:

Should people’s lives be extended indefinitely? If not, should society or the individual choose when to pull the plug? Should a 250-year-old physical teen be treated as an adult and served alcohol or not? Would society take long-term threats, such as the environment, more seriously because people will actually live to see the consequences? Does living so long rob future generations of their right to life? Would you like to live in a society without death?

I figure that, if it happens, we’ll work out a way to cope during the journey – much like Jamais Cascio suggests we’ll cope fine with intelligence augmentation, because it’s an iterative process rather than a momentary leap of change.

Of course, De Grey has already secured himself one form of immortality – the only form of it in which I’d be interested, anyway. I’m sympathetic to the transhumanist project, but the thought of living forever just doesn’t appeal to me. I’ve always theorised that without the ticking clock of mortality we’d have very little to motivate us to create anything new or unique; you struggle to produce a legacy to fill the void of your leaving, if you will. Of course, my attitudes may change as I get older… but even so, if offered the choice right now I’d settle for a standard lifespan minus the gradual decline into senescence and frailty at the end. Death doesn’t scare me, but dying slowly sure does.

Another year, another “regrow your own body parts” story, this one coming from the ever popular domain of dentistry (a field which we have covered before on Futurismic). This time out, the Washington Post jovially informs us that wisdom teeth are a source of stem cells that could be used to regrow and replace missing teeth throughout our adult lives. [image by greefus groinks]

It’s a nuisance, but researchers are closing in on it. In fact, they think the tooth will probably be the first complex organ to be completely regenerated from stem cells. In part this is because teeth are easily accessible — say ahhhhh. So are adult stem cells, found abundantly in both wisdom and baby teeth — no embryos required, and your immune system won’t reject your own cells.

Nobody is predicting when the first whole tooth will be grown in a human, although five to 10 years is a common guess.

Only a decade to wait, then. But knowing dentists, they’ll probably still find a reason to assault your dignity, pain threshold and wallet all at once. Not that I’m bitter or anything. [via SlashDot]

Via Technology Review:

In the latest issue of Advanced Materials, researchers Christiane Gumera and Yadong Wang from the Georgia Institute of Technology announced that they have triggered the regrowth of nerve cells using a polymer coated with chemical structures that resemble acetylcholine, a common neurotransmitter. The research, which is the first to combine a neurotransmitter and a polymer, could one day lead to treatments for neurodegenerative diseases and spinal-cord injuries.

“Lots of people have done biopolymer work,” says Christine Schmidt, a biomedical engineer at the University of Texas at Austin. “But this demonstrates that a polymer with a neurotransmitter can be used to guide growth in the nervous system.”

Link

Anyone who, like myself, has suffered indignity and discomfort (and a serious dent to the bank balance) at the hands of the dentistry profession will probably be overjoyed to hear that scientists have discovered a way to cause the regrowth of teeth in mice. This indicates that the ability to regenerate dentition may still be dormant in human DNA as well, which is definitely something to smile about.

I dread dentistry. It’s painful, undignified and frighteningly expensive – having a tooth replaced with a cap or bridge can cost a month’s salary, and it’s never as good as the real thing. So I’m hoping this ultrasound device that stimulates the regrowth of dental tissue works out well, and heads to these shores as soon as possible. Anything that means I could avoid having root canal surgery for a third time is more than alright in my books.