June 1, 2015 – Only one set of twins has ever been into space, and now those twins are providing an unprecedented opportunity for scientists to better understand the effects of spaceflight on the human body. Scott Kelly began a year-long mission on the International Space Station in March 2015, while his identical twin brother, retired astronaut Mark Kelly, remains on Earth as an experimental control.
“We realized this is a unique opportunity to perform a class of novel studies because we had one twin flying aboard the International Space Station and one twin on the ground,” said Craig Kundrot, Ph.D. and deputy chief scientist of NASA’s Human Research Program. “We can study two individuals who have the same genetics, but are in different environments for one year.”
NASA selected ten separate investigations that will focus in part on the comparison of blood samples collected from Scott and Mark at regular intervals before, during and after the one-year mission. Physiological and psychological testing will also be conducted on the brothers to isolate any changes that can be attributed to life in space.
Colorado State University (CSU) researcher Susan Bailey is among the hand-picked scientists chosen by NASA’s Human Research Program to coordinate and share data and analysis from the investigation as part of an integrated research team.
Bailey, an associate professor in CSU’s Department of Environmental and Radiological Health Sciences, is focusing on chromosomal features, called telomeres, which help protect the body from aging and the cancer-causing effects of radiation. Radiation exposure is a particular concern during space flight – and therefore of special interest to NASA – because astronauts are bombarded by subatomic particles from the sun and other sources.
In the CSU project, the first study of its kind, Bailey will study the twins’ chromosomes in the blood samples. Each chromosome has a protective end-cap called a telomere, which Bailey compares to the plastic tip on a shoelace that keeps the lace from unraveling. As cells divide and replicate during the course of human life, the chromosomes divide as well, and the telomeres gradually erode, eventually leading to the natural death of cells.
Bailey says the erosion rate of these end-caps reveals a lot about a person’s aging process and health. For instance, studies have shown that nonsmokers who get regular exercise often have longer telomeres than those who have unhealthy lifestyles.
For the NASA project, Bailey gathered baseline data on the twins’ telomeres and is now examining how the various demands of life in space – like exposure to radiation, limited diet, and physical and psychological stress – affects those caps on Scott’s chromosomes.
“Taking care of your telomeres is an important thing to do, and having a healthy lifestyle is a big part of that,” Bailey said, adding that previous studies have shown radiation can deteriorate the end caps in as little as five days.
Bailey will also study the 50-year-old twins’ levels of telomerase, an enzyme that restores telomeres and extends the life of cells. The substance is not typically active in the body after birth, with a few exceptions – like in cancer cells, which have a competitive advantage over regular cells because telomerase gives them “immortal” status.
Bailey says that while some researchers have studied the concept that activating telomerase in healthy cells could actually improve health and possibly extend life, it’s a double-edged sword because stimulating telomerase could also feed cancer cells. Clinical trials are being conducted with drugs that reduce telomerase levels as a cancer-fighting strategy.
“The fact that telomerase gets turned off after birth is truly a tumor suppressor,” Bailey said.
Bailey received her bachelor’s degree in biological sciences from CSU in 1980 and returned to campus 21 years later to study the effects of radiation on chromosomes with CSU professor Joel Bedford.
“It was full circle,” Bailey recalls, adding that she immediately became fascinated with the field. “I caught the bug. It was contagious.”
NASA’s Human Research Program (HRP) is funding the 10 pioneering investigations into the molecular, physiological and psychological effects of spaceflight in a continuous effort to reduce the health impacts of human space exploration. The National Space Biomedical Research Institute is partnering with HRP to provide genetic counseling and assisting in the management of the research.
The investigations, which were picked from a pool of 40 proposals, introduce to space physiology the field of -ornics, the integrated study of DNA, RNA, and the entire complement of biomolecules in the human body. Studying human physiology at this fundamental level will provide NASA and the broader spaceflight community with unique information. Investigating the subtle changes – or lack thereof – between the Kelly brothers at this level, after Scott’s year in space and Mark’s year on Earth, could shed light between the nature vs. nurture aspect of the effects of spaceflight on the human body.
Although the investigations conducted on the Kelly brothers are not expected to provide definitive data about the effects of spaceflight on individuals – because there are only two subjects for data collection – they do serve as a demonstration project for future research initiatives. These investigations may identify changes to pursue in research of large astronaut populations.
The following 10 selected proposals, which are from 10 institutions in seven states, will receive a combined $1.5 million during a three-year period:
Emmanuel Mignot, Stanford University School of Medicine, HERO Twin Astronaut Study Consortium (TASC): Immunome Changes in Space
Michael Snyder, Stanford University, HERO Twin Astronaut Study Consortium (TASC) Project: Longitudinal integrated multi-omics analysis of the biomolecular effects of space travel
Brinda Rana, University of California, Proteomic Assessment of Fluid Shifts and Association with Visual Impairment and Intracranial Pressure in Twin Astronauts
Susan Bailey, Colorado State University, Differential effects on telomeres and telomerase in twin astronauts associated with spaceflight
Fred Turek, Northwestern University, HERO Twin Astronaut Study Consortium (TASC) Project: Metagenomic Sequencing of the Bacteriome in GI Tract of Twin Astronauts
Andrew Feinberg, Johns Hopkins University School of Medicine, Comprehensive whole genome analysis of differential epigenetic effects of space travel on monozygotic twins
Christopher Mason, Weill Medical College of Cornell University, The Landscape of DNA and RNA Methylation Before, During, and After Human Space Travel
Mathias Basner, University of Pennsylvania School of Medicine, HERO Twin Astronaut Study Consortium (TASC) Project: Cognition on Monozygotic Twin on Earth
Stuart Lee, Wyle Laboratories, Metabolomic And Genomic Markers Of Atherosclerosis As Related To Oxidative Stress, Inflammation, And Vascular Function In Twin Astronauts
Scott Smith, NASA Johnson Space Center, Biochemical Profile: Homozygous Twin control for a 12 month Space Flight Exposure
Bailey’s project, which netted $150,000 from NASA, is one of many in the CSU Department of Environmental and Radiological Health Sciences to attract funding for the study of radiation and cancer. A team led by Michael Well, a professor in the department, has long received NASA grant money to study the degree to which astronauts face elevated cancer risks from space radiation.
Last month, CSU announced that it would establish a new research facility — the only one of its kind in the world — with a $9 million grant from NASA to help reveal the effects of long-term exposure to space radiation as the nation prepares for a manned mission to Mars. The multimillion-dollar grant from America’s space agency will provide a unique neutron radiation facility at CSU, which will mimic the long-term, low-dose-rate exposures to highly energetic radiation that astronauts would encounter on a multiyear mission to the Red Planet.
Dr. Susan Bailey of Colorado State University in Fort Collins discusses the Telomeres or Twins Study investigation on the International Space Station during an episode of Space Station Live on NASA-TV. The study investigates astronaut chromosomes and how spaceflight affects stress-related aging. Image Credit: NASA-TV
To learn more about Bailey’s telomere investigation, visit: