Rising Stars

How Does Prolonged Space Flight Affect the Human Body? It Takes Twins to Find Out.

What might happen to the human body at a molecular level during a long-haul flight to Mars? Brinda Rana, an Associate Professor at the University of California, San Diego School of Medicine is one of the investigators working with NASA to find out. Brinda’s early research focused on the relationship between genes and common diseases. Most common diseases have an environmental component though, and since it’s a lot easier to prevent disease by altering a person’s environment (as opposed to their genes) Brinda started researching how the interaction between the environment and the genome contributes to disease. Her expertise made her a natural choice to study the effects of space on the genome.

In the fall of 2013, NASA solicited proposals for its landmark Twins Study to investigate the subtle ways in which space travel can affect the human body. Astronaut Scott Kelly would spend nearly a year in space on board the International Space Station, while his identical twin brother Mark (who’s also an astronaut) would remain back on Earth as the control subject. Since the Kelly’s are genetically identical, researchers would be able to see differences that wouldn’t be possible if comparing genetically different individuals. At the time NASA was looking for proposals, Brinda was involved in a number of large twin studies investigating the relative contribution of environmental and genetic influences on things like blood pressure and cognitive aging. She was also investigating how environmental stressors affect the genome. NASA’s Twin Study seemed like a natural progression of her work. Her proposal was accepted, and she is now one of 10 investigators working on the study.

Brinda’s project examines how long-term space travel affects fluid pressure in the brain and consequently vision during and after space flight. On Earth, gravity makes fluid pool down towards our legs. But in the zero-gravity environment of space, fluid flows upwards. Brinda is looking at how the proteins that regulate vasoconstriction, vasodilation, and fluid regulation are affected by space. In addition to the samples taken from on board the International Space Station, Brinda’s group is conducting similar experiments on samples taken from simulated space flights. “NASA conducts head-down studies on a tilt bed to simulate the microgravity environment of space. These studies allow us to investigate some of the physiological effects of space flight here on Earth, such as muscle and bone deconditioning and higher intracranial pressure,” she explains.

Scott Kelly’s year-long mission ended on March 2016 and now that he is safely back on Earth, the Twins Study is in the final stages. Investigators are interpreting the results of their data and preparing to publish. While their detailed findings are still under wraps until publication, Brinda did say that they observed that the structure of the eye was perturbed by space flight. She also said they detected higher levels of several proteins related to musculoskelatal physiology and fluid regulation excreted in the urine during space flight. The 10 Twins Study investigators have integrated the results from their respective molecular studies to collectively support that certain key biological pathways that are altered during space flight. It is the first study integrating data from a number of molecular studies and has also paved the way for future "omics" research in space.

Mark and Scott Kelly (image: NASA)

“Our goal is to investigate how long-duration space flight affects the body at the molecular level in order to understand the underlying molecular pathways involved in physiological manifestations of the effects of space flight,” says Brinda. With a better understanding of these pathways, their research can enable NASA to develop early diagnostic tools and preventative measures (both therapeutic and behavioural) against the negative effects space travel can have on the body. The results of the Twins Study could help not only astronauts return home safely, but also potentially make space travel more accessible to the public. Additionally, the molecular pathways that are related to the physiological issues astronauts face may provide information for Earth-related disorders such as glaucoma, traumatic brain injury, atherosclerosis (plaque building up in your arteries), osteoporosis. “Our findings may provide a way to help those suffering from these conditions back on Earth too,” adds Brinda.

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Title How Does Prolonged Space Flight Affect the Human Body? It Takes Twins to Find Out.
Posted on May 07, 2018 at 09:44 am.
Written by Sarah Binns
Category Rising Stars
Tags Psychiatry & Psychology