Three LLNL biomedical scientists—left to right, Matt Coleman, Angela Evans and Aimy Sebastian—are part of a team that has found new biomarkers that can be used for diagnostic purposes and potentially as predictive tools of the risks associated with deep space flight. Credit: Julie Russell
Analyzing 20-year-old blood samples, an international team of scientists has found new biomarkers that can be used as predictive tools of the risks associated with deep spaceflight.
Scientists have long known spaceflight comes with risky heath effects, although the exact mechanisms and extent of the effects has largely gone unknown. In the past decade or so, research has ramped up as NASA prepares to send astronauts—and maybe even civilians—on long journeys into deep space. The Twins Study comparing ISS-bound Scott Kelly to his identical twin brother, earth-bound Mark Kelly, is a landmark study in this area.
Now, a research team led by Mt. Sinai scientists has adapted the analysis to include 14 astronauts who flew short (5 to 13 days) ISS missions.
In their study, published in Frontiers in Genetics, the scientists analyzed RNA isolated from exosome samples of blood taken from space shuttle astronauts between 1998 and 2001. The samples were taken 10 days before the astronauts went into space, and then again three days after they returned from low earth orbit.
“We knew that nucleic acid within exosomes can be intact for 15-20 years, but we weren’t sure how space travel would affect them and whether we would find intact exosomes containing nucleic acids in the two-decade-old blood from space shuttle astronauts that was stored away,” said study co-author Matt Coleman, a biomedical scientist at Lawrence Livermore National Laboratory (LLNL).
Exosomes are small extracellular lipid-protein spheres that carry other molecules inside, allowing cells and tissues to communicate with each other. Long non-coding RNA (lncRNA), which controls and turns on cell mechanisms, can be found in exosomes among other types of RNA.
The researchers found 27 differentially expressed lncRNAs, or biomarkers for space flight, that changed from before space flight to after flight. Of the 27 differentially expressed genes, 15 were upregulated while 12 were down-regulated. Seven of the lncRNA were found on chromosome 1, with the rest spread evenly across 14 other chromosomes.
To gain further insight into the IncRNAs, the team performed a computational analysis that suggested the dysregulated pathways are associated with cancer, neurodegeneration (Alzheimer’s and Huntington’s disease, amyotrophic lateral sclerosis), and cardiovascular disease (myocarditis and atherosclerosis). Furthermore, 7 out of the 27 lncRNAs may have a prognostic value in cancer.
“Because the lncRNA can modulate a large number of genes, understanding these genes and the pathways they’re associated with—such as general health or cardiovascular disease—would allow us to identify who needs to get specific medicine, change their diet or get more exercise to ward off any negative effects of spaceflight,” said Coleman.
While the team’s current study focuses on lncRNA, the scientists expect to publish three more papers over the next three to six months about other types of RNA identified within other exosomes that also play a role in health and diseases and could furnish more information about the risks associated with spaceflight.