@neysastudies

Toxic ‘zombie’ cells seen for 1st time in Alzheimer’s

A type of cellular stress known to be involved in cancer and aging has now been implicated, for the first time, in Alzheimer’s disease. UT Health San Antonio faculty researchers reported the discovery in the journal Aging Cell.

The team found that the stress, called cellular senescence, is associated with harmful tau protein tangles that are a hallmark of 20 human brain diseases, including Alzheimer’s and traumatic brain injury. The researchers identified senescent cells in postmortem brain tissue from Alzheimer’s patients and then found them in postmortem tissue from another brain disease, progressive supranuclear palsy.

Cellular senescence allows the stressed cell to survive, but the cell may become like a zombie, functioning abnormally and secreting substances that kill cells around it. “When cells enter this stage, they change their genetic programming and become pro-inflammatory and toxic,” said study senior author Miranda E. Orr, Ph.D., VA research health scientist at the South Texas Veterans Health Care System, faculty member of the Sam and Ann Barshop Institute for Longevity and Aging Studies, and instructor of pharmacology at UT Health San Antonio. “Their existence means the death of surrounding tissue.”

Improvements in brain structure and function

The team confirmed the discovery in four types of mice that model Alzheimer’s disease. The researchers then used a combination of drugs to clear senescent cells from the brains of middle-aged Alzheimer’s mice. Such drugs are called senolytics. The drugs used by the San Antonio researchers are dasatinib, a chemotherapy medication that is U.S. Food and Drug Administration-approved to treat leukemia, and quercetin, a natural flavonoid compound found in fruits, vegetables and some beverages such as tea.

After three months of treatment, the findings were exciting. “The mice were 20 months old and had advanced brain disease when we started the therapy,” Dr. Orr said. “After clearing the senescent cells, we saw improvements in brain structure and function. This was observed on brain MRI studies (magnetic resonance imaging) and postmortem histology studies of cell structure. The treatment seems to have stopped the disease in its tracks.”

“The fact we were able to treat very old mice and see improvement gives us hope that this treatment might work in human patients even after they exhibit symptoms of a brain disease,” said Nicolas Musi, M.D., study first author, who is Professor of Medicine and Director of the Sam and Ann Barshop Institute at UT Health San Antonio. He also directs the VA-sponsored Geriatric Research, Education and Clinical Center (GRECC) in the South Texas Veterans Health Care System.

Typically, in testing an intervention in Alzheimer’s mice, the therapy only works if mice are treated before the disease starts, Dr. Musi said.

Tau protein accumulation is responsible

In Alzheimer’s disease, patient brain tissue accumulates tau protein tangles as well as another protein deposit called amyloid beta plaques. The team found that tau accumulation was responsible for cell senescence. Researchers compared Alzheimer’s mice that had only tau tangles with mice that had only amyloid beta plaques. Senescence was identified only in the mice with tau tangles.

In other studies to confirm this, reducing tau genetically also reduced senescence. The reverse also held true. Increasing tau genetically increased senescence.

Importantly, the drug combination reduced not only cell senescence but also tau tangles in the Alzheimer’s mice. This is a drug treatment that does not specifically target tau, but it effectively reduced the tangle pathology, Dr. Orr said.

“When we looked at their brains three months later, we found that the brains had deteriorated less than mice that received placebo control treatment,” she said. “We don’t think brain cells actually grew back, but there was less loss of neurons, less brain ventricle enlargement, improved cerebral blood flow and a decrease in the tau tangles. These drugs were able to clear the tau pathology.”

Potentially a therapy to be tested in humans

“This is the first of what we anticipate will be many studies to better understand this process,” Dr. Musi said. “Because these drugs are approved for other uses in humans, we think a logical next step would be to start pilot studies in people.”

The drugs specifically target—and therefore only kill—the senescent cells. Because the drugs have a short half-life, they are cleared quickly by the body and no side effects were observed.

Dasatinib is an oral medication. The mice were treated with the combination every other week. “So in the three months of treatment, they only received the drug six times,” Dr. Orr said. “The drug goes in, does its job and is cleared. Senescent cells come back with time, but we expect that it would be possible to take the drug again and be cleared out again. That’s a huge benefit—it wouldn’t be a drug that people would have to take every day.”

Dosage and frequency in humans would need to be determined in clinical trials, she said.

Next, the researchers will study whether cell senescence is present in traumatic brain injury. TBI is a brain injury that develops tau protein accumulation and is a significant cause of disability in both military and non-military settings, Dr. Orr said.

Coffee in Space: Keeping Crew Members Grounded in Flight

Happy National Coffee Day, coffee lovers!

On Earth, a double shot mocha latte with soymilk, low-fat whip and a caramel drizzle is just about as complicated as a cup of coffee gets. Aboard the International Space Station, however, even just a simple cup of black coffee presents obstacles for crew members.

Understanding how fluids behave in microgravity is crucial to bringing the joys of the coffee bean to the orbiting laboratory. Astronaut Don Pettit crafted a DIY space cup using a folded piece of overhead transparency film. Surface tension keeps the scalding liquid inside the cup, and the shape wicks the liquid up the sides of the device into the drinker’s mouth.

The Capillary Beverage investigation explored the process of drinking from specially designed containers that use fluid dynamics to mimic the effect of gravity. While fun, this study could provide information useful to engineers who design fuel tanks for commercial satellites!

The capillary beverage cup allows astronauts to drink much like they would on Earth. Rather than drinking from a shiny bag and straw, the cup allows the crew member to enjoy the aroma of the beverage they’re consuming.

On Earth, liquid is held in the cup by gravity. In microgravity, surface tension keeps the liquid stable in the container.

The ISSpresso machine brought the comforts of freshly-brewed coffees and teas to the space station. European astronaut Samantha Cristoforetti enjoyed the first cup of espresso brewed using the ISSpresso machine during Expedition 43.

Now, during Expedition 53, European astronaut Paolo Nespoli enjoys the same comforts.

Astronaut Kjell Lindgren celebrated National Coffee Day during Expedition 45 by brewing the first cup of hand brewed coffee in space.

We have a latte going on over on our Snapchat account, so give us a follow to stay up to date! Also be sure to follow @ISS_Research on Twitter for your daily dose of space station science.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.

6K notes View Post

redplanet44

7 years ago

Eric Magnus Lensherr-sphere

Magnetospheres: How Do They Work?

The sun, Earth, and many other planets are surrounded by giant magnetic bubbles.

Space may seem empty, but it’s actually a dynamic place, dominated by invisible forces, including those created by magnetic fields. Magnetospheres – the areas around planets and stars dominated by their magnetic fields – are found throughout our solar system. They deflect high-energy, charged particles called cosmic rays that are mostly spewed out by the sun, but can also come from interstellar space. Along with atmospheres, they help protect the planets’ surfaces from this harmful radiation.

It’s possible that Earth’s protective magnetosphere was essential for the development of conditions friendly to life, so finding magnetospheres around other planets is a big step toward determining if they could support life.

But not all magnetospheres are created equal – even in our own backyard, not all planets in our solar system have a magnetic field, and the ones we have observed are all surprisingly different.

Earth’s magnetosphere is created by the constantly moving molten metal inside Earth. This invisible “force field” around our planet has an ice cream cone-like shape, with a rounded front and a long, trailing tail that faces away from the sun. The magnetosphere is shaped that way because of the constant pressure from the solar wind and magnetic fields on the sun-facing side.

Earth’s magnetosphere deflects most charged particles away from our planet – but some do become trapped in the magnetic field and create auroras when they rain down into the atmosphere.

We have several missions that study Earth’s magnetosphere – including the Magnetospheric Multiscale mission, Van Allen Probes, and Time History of Events and Macroscale Interactions during Substorms (also known as THEMIS) – along with a host of other satellites that study other aspects of the sun-Earth connection.

Mercury, with a substantial iron-rich core, has a magnetic field that is only about 1% as strong as Earth’s. It is thought that the planet’s magnetosphere is stifled by the intense solar wind, limiting its strength, although even without this effect, it still would not be as strong as Earth’s. The MESSENGER satellite orbited Mercury from 2011 to 2015, helping us understand our tiny terrestrial neighbor.

After the sun, Jupiter has by far the biggest magnetosphere in our solar system – it stretches about 12 million miles from east to west, almost 15 times the width of the sun. (Earth’s, on the other hand, could easily fit inside the sun.) Jupiter does not have a molten metal core like Earth; instead, its magnetic field is created by a core of compressed liquid metallic hydrogen.

One of Jupiter’s moons, Io, has intense volcanic activity that spews particles into Jupiter’s magnetosphere. These particles create intense radiation belts and the large auroras around Jupiter’s poles.

Ganymede, Jupiter’s largest moon, also has its own magnetic field and magnetosphere – making it the only moon with one. Its weak field, nestled in Jupiter’s enormous shell, scarcely ruffles the planet’s magnetic field.

Our Juno mission orbits inside the Jovian magnetosphere sending back observations so we can better understand this region. Previous observations have been received from Pioneers 10 and 11, Voyagers 1 and 2, Ulysses, Galileo and Cassini in their flybys and orbits around Jupiter.

Saturn’s moon Enceladus transforms the shape of its magnetosphere. Active geysers on the moon’s south pole eject oxygen and water molecules into the space around the planet. These particles, much like Io’s volcanic emissions at Jupiter, generate the auroras around the planet’s poles. Our Cassini mission studies Saturn’s magnetic field and auroras, as well as its moon Enceladus.

Uranus’ magnetosphere wasn’t discovered until 1986 when data from Voyager 2’s flyby revealed weak, variable radio emissions. Uranus’ magnetic field and rotation axis are out of alignment by 59 degrees, unlike Earth’s, whose magnetic field and rotation axis differ by only 11 degrees. On top of that, the magnetic field axis does not go through the center of the planet, so the strength of the magnetic field varies dramatically across the surface. This misalignment also means that Uranus’ magnetotail – the part of the magnetosphere that trails away from the sun – is twisted into a long corkscrew.

Neptune’s magnetosphere is also tilted from its rotation axis, but only by 47. Just like on Uranus, Neptune’s magnetic field strength varies across the planet. This also means that auroras can be seen away from the planet’s poles – not just at high latitudes, like on Earth, Jupiter and Saturn.

Does Every Planet Have a Magnetosphere?

Neither Venus nor Mars have global magnetic fields, although the interaction of the solar wind with their atmospheres does produce what scientists call an “induced magnetosphere.” Around these planets, the atmosphere deflects the solar wind particles, causing the solar wind’s magnetic field to wrap around the planet in a shape similar to Earth’s magnetosphere.

What About Beyond Our Solar System?

Outside of our solar system, auroras, which indicate the presence of a magnetosphere, have been spotted on brown dwarfs – objects that are bigger than planets but smaller than stars.

There’s also evidence to suggest that some giant exoplanets have magnetospheres. As scientists now believe that Earth’s protective magnetosphere was essential for the development of conditions friendly to life, finding magnetospheres around exoplanets is a big step in finding habitable worlds.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

2K notes View Post

redplanet44

7 years ago

ISS Expedition 54 crew land safely in Kazakhstan

Houston TX (SPX) Feb 28, 2018 Three members of the Expedition 54 crew aboard the International Space Station (ISS), including NASA astronauts Mark Vande Hei and Joe Acaba, returned to Earth on Tuesday after months of performing research and spacewalks in low-Earth orbit. Vande Hei, Acaba and cosmonaut Alexander Misurkin of the Russian space agency Roscosmos landed at 9:31 p.m. EST (8:31 a.m. Feb. 28 in Kazakhstan) sout Full article

9 notes View Post

redplanet44

7 years ago

2K notes View Post

redplanet44

7 years ago

Like the crazy eye of the universe

The Hydrogen Atom

831 notes View Post

redplanet44

7 years ago

‘Junk’ DNA Plays Crucial Role in Holding Genome Together: Study

Jagannathan et al propose that chromocenter and satellite DNA serves a fundamental role in encapsulating the full complement…more Image credit: Lisichik.

8 notes View Post

redplanet44

7 years ago

Don't drink dihydrogen monoxide. Everybody dies who does!

Dihydrogen Monoxide Bottle

4K notes View Post

redplanet44

7 years ago

Biomimicry

Brittle starfish shows how to make tough ceramics

Nature inspires innovation. An international team lead by researchers at Technion – Israel Institute of Technology, together with ESRF -the European Synchrotron, Grenoble, France- scientists, have discovered how a brittle star can create material like tempered glass underwater. The findings are published in Science and may open new bio-inspired routes for toughening brittle ceramics in various applications that span from optical lenses to automotive turbochargers and even biomaterial implants.

A beautiful, brainless brittle star that lives in coral reefs has the clue to super tough glass. Hundreds of focal lenses are located on the arms of this creature, which is an echinoderm called Ophiocoma wendtii. These lenses, made of chalk, are powerful and accurate, and the deciphering of their crystalline and nanoscale structure has occupied Boaz Pokroy and his team, from the Technion-Israel Institute of Technology, for the past three years. Thanks to research done on three ESRF beamlines, ID22, ID13 and ID16B, among other laboratories, they have figured out the unique protective mechanism of highly resistant lenses.

As an example, take tempered glass. It is produced by exerting compressive pressure on the glass which compresses it and leaves it more compact than in its natural state. Glass tempering is performed by rapidly heating and then rapidly cooling the material. In this process, the outside of the material cools more quickly than the inside and thereby compresses the inside. Ophiocoma wendtiilenses are created in the open sea, at room temperature, unlike tempered glass. “We have discovered a strategy for making brittle material much more durable under natural conditions. It is ‘crystal engineering’ and tempering without heating and quenching – a process that could be very useful in materials engineering,” explains Pokroy.