January 30, 2014
Ice Worms Help Expand Knowledge On Cold Protection
Brett Smith for redOrbit.com - Your Universe Online
While the Polar Vortex may have kept temperatures around New Jersey dangerously low, scientists at the state’s Rutgers University-Camden have been working on combating the cold on a biological level, by keeping cellular energy up.
“If you want to live in the cold, you have to make lots of energy,” said Daniel Shain, a professor of biology at Rutgers–Camden. “That means your cells would have to produce more adenosine triphosphate (ATP), the currency of energy for all life on Earth. When we get cold, our ATP levels plummet.”
To investigate a system for sustaining higher ATP, Shain has committed himself to researching ice worms, the only annelid worms known to spend their whole lives in glacial ice. In addition to potential protection from the cold, keeping higher ATP levels in human cells could bring about improvements in organ transplantation. Donated organs have to be transplanted into recipients within a very brief time frame – often 24 hours or less. However, that window may be extended by boosting the ATP levels when the organ is being refrigerated
“We have tried to manipulate human cells to have these elevated ATP levels to mimic ice worm physiology,” Shain said. “The idea is to try and keep these organs alive from days to weeks instead of hours.”
“The easiest way to think about it is that we have a thermostat in our body that regulates energy,” he added. “It keeps energy levels from getting too high. In ice worms, that thermostat is broken. They have all this extra ATP.”
Shain said adding extra ATP to a cellular system at colder temperatures allows the processes of the cell to continue working.
“Everything slows in lower temperature. Molecules move more slowly and biochemical reactions occur when molecules collide,” Shain explained to redOrbit. “So if molecules are moving more slowly, they have a lower chance of colliding – slowing down reactions in your body.”
“To compensate for that, you add more stuff – in this case ATP,” he continued. “ATP needs to collide with other molecule in the cell for those reactions to move forward. So you just increase the probability of molecular collisions.”
Ice worms aren’t completely resistant to the effects of freezing temperatures. They tend to live on coastal glaciers, where the temperature remains steady, instead of on inland glaciers, where temperatures are in flux and can get much colder. If temperatures drop a few degrees below zero, the ice worms will die, Shain said.
“They are paradoxically very sensitive to freezing,” the Rutgers researcher noted. “They’re able to live right at the freezing point thanks to their elevated ATP levels.”
The Rutgers scientist said he has had some success trying to replicate the behavior of ice worm cells while working with cells from a fly.
“We can genetically change machinery of a fly much more easily than we can in humans,” Shain said. “In a fly, you can break that machinery pretty easily and there’s only one thermostat in a fly.”
“The problem with humans is there’s more than one thermostat – there’s multiple thermostats. So if you break one, then the other thermostat kicks in,” he added. “We’re not sure how many thermostats are in a human cell. There may be as many as four, which is problematic. We can try to get rid of one, but then there’s another one. Then, well, we have get rid of that one – then there’s another one. It a real pain in the butt.”
“We now feel like we partially understand the mechanism for making this change and we’ve only just scratched the surface of applying it to human cells,” Shain said. “We’ve learned it’s not so easy, but it’s not impossible, either.”