NASA's John F. Kennedy Space Center
Some of the core beliefs about what causes Alzheimer's and Parkinson's disease may be wrong, and flying an experiment on the International Space Station could provide the best way to show it, say researchers at NASA's Kennedy Space Center in Florida.
Scientists at Kennedy, working with a pioneering researcher at the Florida Institute of Technology (FIT), want to send a set of proteins to the space station where the material would be free to collect together into large, complex structures without gravity tearing them apart.
Their thought is that Alzheimer's and other diseases including those that develop from head injuries in sports occur not because normal proteins become corrupted, but because with aging, or after repeated concussions, changes occur in the environment within the brain that cause certain proteins to cling together in ever-larger threads that choke off brain cells, slowly depriving a person of memories and brain functions.
David Tipton, chief medical officer at Kennedy, said current theories about the cause of Alzheimer's and similar diseases perhaps misidentify the problem. He is working with Dan Woodard, an aerospace physician with InoMedic Health Applications at Kennedy, and Shaohua Xu, a professor at FIT who proposed the theory while working at the Space Life Sciences Lab at Kennedy.
"We believe it may be a colloidal chemical process rather than a biochemical process," Tipton said. "NASA has a lot of background and experience in colloidal chemistry and crystal chemistry so this is a perfect opportunity for NASA's experience, and knowledge and equipment and capabilities. It can be used to evaluate whether this theory could indeed cause the kinds of changes in cells associated with these diseases and thereby allow a different approach by the pharmaceutical and medical industries to potentially come up with new treatments for these diseases."
NASA has an extensive history of studying crystal formation and processes similar to the protein development the researchers propose. Astronauts operated crystal growing experiments during space shuttle missions and during flights to the Russian Mir space station.
"We've been able to see almost at the atomic level how these individual protein molecules join together," said Woodard. "We can see that it is not consistent with normal biochemistry. But if we look outside the field of biochemistry and look at another field called colloidal chemistry, we actually find very similar processes, except that they aren't usually associated with living organisms."
The research can only go so far on Earth because gravity keeps the protein structures from growing beyond a certain size in the laboratory before they collapse of their own weight.
"It appears we might have the technology and experience to answer a few questions here," Tipton said.
The scientists want to send a container holding the proteins to the International Space Station to find out if protein strands grow as the researchers expect. If their theory holds, the proteins should clump together in larger structures than are seen in Earth's normal gravity.
The team has been working with scientists at NASA's Glenn Research Center in Ohio who built several prior experiments that examined colloidal processes in space.
"In zero-gravity, these colloidal interactions can occur much faster because gravity isn't pulling the colloid out of suspension," Tipton said. "In Alzheimer's, it takes 20, 30, 40 years. If you wait 20, 30 or 40 years, you're research isn't going to move very fast."
As the particles accumulate, they may even take on a different state in the same way that the particles which make up paint behave one way when the paint is wet, but collect together and become a solid coating as the paint dries in the air.
"It appears that perfectly normal proteins are capable of aggregating to form threads that then accumulate to choke these cells," Woodard said. "The mystery is why for many people these proteins can remain soluble and function normally in the brain for an entire lifetime, while in other cases the same proteins undergo aggregation."
Answering that small riddle may prove to be the fundamental element in solving the whole problem.
"Sometimes we can provide a piece of the puzzle that is vital in all the other pieces fitting together," Tipton said.
Depending on what a space-based experiment shows, the researchers say they would still be far removed from testing on actual brains.
"We're several years from working on brains," Tipton said. "We're still working to demonstrate that this theory could indeed be the cause of protein aggregation into the types of fibers that are seen in brains."
Both Tipton and Woodard are confident their theory is on the right track to detecting the cause of the brain-crippling diseases.
"In the vast majority of people who get Alzheimer's, no genetic change has been identified," Woodard said. "The proteins are in fact genetically normal, so something else must be the driving factor in causing aggregation. We believe it must have something to do with colloidal forces. We have to remember that proteins are still just ordinary chemicals and are subject to non-biological actions."