IN a breakthrough discovery, researchers in Japan have discovered a protein from micro-animals known as tardigrades, or “water bears,” that can protect human DNA from high levels of radiation.
The scientists, who published their findings in the journal Nature Communications, were studying the tiny marine creatures’ incredible resilience when they made the discovery. Tardigrades, more commonly known as water bears, are microscopic eight-legged segmented marine animals that can withstand extreme conditions, including temperature ranges from absolute zero (-273 degrees Celsius) to 100 degrees Celsius, high levels of radiation, extremely high pressures, and even the vacuum of outer space.
The study team led by Assistant Professor Takekazu Kunieda of the University of Tokyo sequenced the genome of Ramazzottius varieornatus, one of the most stress-tolerant tardigrade species known, and which is particularly resistant to high levels of radiation.
“While researchers have long been fascinated by their resilience, we still don’t really know how it’s possible,” said Kunieda. “We need to find the molecules that allow tardigrades to tolerate such conditions.”
The research team discovered that a protein helped the marine animals protect their DNA when irradiated.
When human cells in a culture were given the ability to produce the protein, which the researchers named Damage Suppressor (Dsup), the cells showed approximately half the DNA damage when exposed to X-ray radiation compared with normal cells. In addition, the study notes, the cultured cells that could create Dsup were still capable of reproducing.
“What’s astonishing is that previously, molecules that repair damaged DNA were thought to be important for tolerating radiation. On the contrary, Dsup works to minimize the harm inflicted on the DNA,” said co-first author Takuma Hashimoto, a project researcher at the University of Tokyo’s Graduate School of Science, who performed the tolerance experiments.
The scientists suggested that the tardigrade genome sequence could contain other Dsup-like proteins, and that more of these molecules that increase the creature’s resilience and possibly have applications to human medicine could be found in future research.