Anti-aging elixir could be hiding in 'indestructible' tardigrades, say scientists who found microscopic creature's proteins slow cell damage

Scientists studying the mysterious creatures called tardigrades may have found a new possible tool in their quest to slow human aging.

Sometimes called water bears, the near-microscopic, eight-legged animals can survive conditions that would kill most other forms of life.

That is because they have proteins that form gels inside of cells and slow down life processes down cell damage - and the gel could be an anti-aging elixir.

A team of international researchers  introduced tardigrade proteins to human cells in a lab, finding they slowed down and entered a sort of hibernation - just like those in the 'indestructible' creatures.

A team of international researchers introduced tardigrade proteins to human cells in a lab, finding they slowed down and entered a sort of hibernation - just like those in the 'indestructible' creatures 

Tardigrades are small, water-dwelling, segmented micro-animals with eight legs that live in damp habitats such as moss or lichen

The new results offer clues for a way to put people's cells or tissues into a form of suspended animation, just like a tardigrade does when it is under stress.

READ MORE: Scientists want to see just how 'indestructible' tardigrades really are 

Scientists proposed a plan to fire tardigrades to distant stars at 100 million miles per hour using massive lasers in a bid to see how interstellar space travel affects them.

Just two-hundredths of an inch long, tardigrades can survive the immense pressure of the deep sea, extreme high and low temperatures, total dehydration, long-term famine, and even the vacuum and radiation of outer space.

Their secret: a form of suspended animation. 

When tardigrades get stressed, their whole body begins to slow down, including on a microscopic level.

They can enter a state called biostasis, where they can tolerate almost complete dehydration for years until water is available again.

Now, scientists have discovered that the proteins that make biostasis possible in tardigrades can have similar effect human cells.

Senior research Scientist Silvia Sanchez-Martinez at the University of Wyoming said: 'Amazingly, when we introduce these proteins into human cells, they gel and slow down metabolism, just like in tardigrades.

'Furthermore, just like tardigrades, when you put human cells that have these proteins into biostasis, they become more resistant to stresses, conferring some of the tardigrades' abilities to the human cells.' 

This discovery could mean that tardigrades are an important weapon in the fight against human aging.

If our cells could resist DNA damage from the sun or toxic exposures like tardigrades' cells can, then perhaps the entire aging process could be slowed, the scientists behind the new study have suggested. 

More immediately, this discovery means that human stem cells or medicines like blood products for hemophilia that require refrigeration could be shipped without it, expanding access to lifesaving drugs for people in developing countries.

The crucial part of this process is a set of proteins called CAHS, 'intrinsically disordered' proteins that slow down the tardigrade to the point of biostasis. 

In biostasis the animal turns into a 'tun,' the name for a dormant tardigrade.

This ability is one of many that enables them to survive extreme conditions.

This image compares one protein that doesn't form gels, lysozyme (top left), to two that do: CAHS D (bottom) and gelatin (top right). Gelatin, the common ingredient in desserts, has a very similar structure to tardigrades' CAHS proteins, hinting at their gel-forming abilities

Tardigrades are classed as extremophiles as they can survive dry conditions by changing into a desiccated state, in which they can remain for many years. 

In the tun state, tardigrades can take all sorts of abuse without being hurt.

They can be exposed to many times the amount of radiation that would kill a person, but damage suppressors in their DNA keep them safe.

They can be heated up to 300 degrees Fahrenheit or chilled to nearly 500 degrees below zero. 

As long as they remain in biostasis, they are safe.

Scientists used to think this was thanks to a sugar called trehalose, which tardigrades and other dehydration-tolerant microorganisms can produce.

But more recently, they've discovered that's not the whole picture.

While trehalose does seem to protect some sensitive biological material, it seems that CAHS proteins are responsible for slowing everything down and pausing tardigrades in time.

In biostasis, the liquids in a tardigrade's body into gels as molecules slow down to enter the tun state.

Human kidney cells treated with CAHS D (second row from top) survived stress much better than untreated cells (top row) or cells given gene therapy to be stress-tolerant (bottom two rows)

Previous research showed that as the tardigrade begins biostasis, its body produces more and more CAHS proteins.

And the more CAHS proteins, the more gel-like the animal's insides become.

In the new study, introducing CAHS proteins to human cells made them slow down and gel, too.

'Amazingly, when we introduce these proteins into human cells, they gel and slow down metabolism, just like in tardigrades,' said study author Silvia Sanchez-Martinez, senior research scientist at the University of Wyoming.

'Furthermore, just like tardigrades, when you put human cells that have these proteins into biostasis, they become more resistant to stresses, conferring some of the tardigrades' abilities to the human cells,' Sanchez-Martinez said.

What's more, the process could be reversed - just like tardigrades exiting biostasis. 

'When the stress is relieved, the tardigrade gels dissolve, and the human cells return to their normal metabolism,' said lead author Thomas Boothby, assistant professor of molecular biology at University of Wyoming.

The results give insights into how tardigrades can cultivate such otherworldly stress tolerance, but that's not all, Boothby, Sanchez-Martinez, and their co-authors wrote: 'Our findings provide an avenue for pursuing technologies centered around the induction of biostasis in cells and even whole organisms to slow aging and enhance storage and stability.'

The study was published in the journal Protein Science. 

WHAT ARE TARDIGRADES?

Tardigrades, also known as water bears, are said to be the most indestructible animals in the world.

These small, segmented creatures come in many forms - there are more than 900 species of them - and they're found everywhere in the world, from the highest mountains to the deepest oceans.

Tardigrades, also known as water bears, are said to be the most indestructible animals in the world.

They have eight legs (four pairs) and each leg has four to eight claws that resemble the claws of a bear.

Boil the 1mm creatures, freeze them, dry them, expose them to radiation and they're so resilient they'll still be alive 200 years later.

An illustration of a tardigrade (water bear) is pictured 

Water bears can live through temperatures as low as -457 degrees, heat as high as 357 degrees, and 5,700 grays of radiation, when 10-20 grays would kill humans and most other animals.

Tardigrades have been around for 530 million years and outlived the dinosaurs.

The animals can also live for a decade without water and even survive in space.