Researchers Uncover Challenges in Tardigrade DNA Protein for Space Safety

Exploring the cosmos poses unique challenges, particularly regarding cosmic radiation. Scientists have long sought ways to protect astronauts from this radiation without the impracticality of heavy shielding. Recent research led by Corey Nislow at the University of British Columbia has revealed the complexities behind using a protein derived from tardigrades, known as Dsup (damage suppressor), to enhance cellular resistance to radiation.

Tardigrades, tiny creatures renowned for their resilience, can endure extreme conditions such as high radiation, intense heat, and even the vacuum of space. In a pivotal study from 2016, Dsup was identified as a significant factor in their survival capabilities. Initial findings suggested that genetically engineering human cells to produce Dsup could bolster resistance to radiation without adverse effects. This sparked interest in using Dsup to shield astronauts during space missions.

Nislow had previously expressed optimism about delivering Dsup-encoding mRNAs encapsulated in lipid nanoparticles (LNPs), a method similar to that used in mRNA COVID-19 vaccines. He noted, “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.” However, recent investigations have unveiled critical limitations.

The research team conducted extensive studies involving yeast cells modified to produce Dsup. They discovered that while Dsup can protect DNA, excessive levels can be detrimental. High concentrations were found to be fatal, while even moderate levels impaired cell growth. Nislow explained that Dsup protects DNA by physically enveloping it, which, while offering protection, impedes access for essential cellular processes, including DNA replication and repair.

As the research progresses, questions arise about the feasibility of utilizing Dsup for human applications, particularly in space travel. Nislow emphasized the necessity of controlling the production of Dsup within cells, stating, “It will be crucial to ensure that Dsup is produced only in the cells where it is needed and at the right levels.”

Other researchers are also investigating Dsup’s potential. James Byrne from the University of Iowa is exploring whether Dsup can aid in protecting healthy cells during radiation therapy for cancer. Byrne cautioned that if Dsup were continuously produced throughout the body, it could negatively impact health. He suggested that transient production during critical times might yield benefits.

Similarly, Simon Galas from the University of Montpellier highlighted that while high doses of Dsup can be toxic, low levels have been shown to extend the lifespan of nematode worms by providing protection against oxidative stress. His team continues to investigate the mechanisms behind Dsup’s functionality.

Another researcher, Jessica Tyler from Weill Cornell Medicine, has also modified yeast to produce Dsup. She reported that at lower levels than those tested by Nislow, Dsup appeared to have beneficial effects without impacting growth negatively. Tyler acknowledged the importance of regulating Dsup production levels.

Despite the challenges, researchers remain hopeful about the future of Dsup and its applications. Nislow expressed confidence in the advancement of delivery systems, stating, “There’s so much money and attention on delivery systems. It’s a problem that so many people in pharma are motivated to solve.” The ongoing exploration of Dsup could pave the way for innovative solutions to protect astronauts and potentially even cancer patients, underscoring the intricate balance between benefit and risk in scientific advancement.