A protein from tardigrades, known for their extreme resilience, offers potential protection against cosmic radiation for astronauts but comes with significant cellular costs, according to new research. Scientists at the University of British Columbia found that while dsup shields DNA from damage, it can impair cell growth and even cause death at higher levels. The findings complicate hopes for using the protein in space missions.
Tardigrades, microscopic animals renowned for surviving extreme conditions like radiation and the vacuum of space, have long intrigued researchers seeking ways to safeguard astronauts from cosmic threats. In 2016, studies revealed that a tardigrade protein called dsup, or damage suppressor, enhances human cells' resistance to radiation without apparent drawbacks at the time.
This sparked ideas for protecting space travelers by delivering dsup via mRNA encased in lipid nanoparticles, similar to covid-19 vaccines. Corey Nislow, a researcher at the University of British Columbia in Vancouver, initially supported this approach. "Two to three years ago, I was fully on board with the idea that, let’s deliver dsup mRNA in an LNP to crew members on space missions," he said.
However, Nislow's recent extensive tests on yeast cells genetically modified to produce dsup paint a more cautious picture. The protein not only guards against a broader array of mutation-causing chemicals beyond radiation but also hinders cell function. High levels proved fatal, while even moderate amounts slowed growth. "There’s a cost for every benefit that we’ve seen," Nislow noted.
The mechanism involves dsup enveloping DNA, which blocks access for proteins needed to transcribe RNA, replicate DNA, or perform repairs. In cells with insufficient repair proteins, dsup exacerbated damage by preventing fixes.
Experts offered mixed but constructive views. James Byrne at the University of Iowa, exploring dsup for cancer radiation therapy, agreed on the need for targeted, temporary production to avoid health costs. Simon Galas at the University of Montpellier in France confirmed toxicity at high doses but highlighted benefits at low levels, such as extended lifespan in nematodes via oxidative stress protection. Jessica Tyler at Weill Cornell Medicine in New York reported positive effects in yeast at lower concentrations without growth impacts, stressing precise dosing.
Nislow remains optimistic about future delivery technologies, driven by pharmaceutical investments, to enable controlled dsup expression in specific cells. The study appears in bioRxiv (DOI: 10.64898/2025.12.24.696340).
