Researchers from the University of Tokyo found a protein that can protect human DNA from being damaged by X-rays. The protein was isolated from water bears, tiny and nearly indestructible aquatic creatures. The findings are in a paper that was just published in the journal Nature Communications.
Water bears, known as tardigrades in the scientific community, are water-dwelling animals that reach a length of about 0.5 mm at maturity. They are renowned for their incredible resilience; water bears can survive extreme temperatures, high amounts of pressure, and even the harsh conditions of outer space. They can go into a kind of hibernation that allows them to survive without food or water for over 30 years, springing back to life after being rehydrated. The animals have even survived liquid nitrogen baths and can withstand temperatures that aren’t even found on the planet. Water bears are also resistant to radiation, especially the species picked for the study, Ramazzottius varieornatus.
The team of scientists sequenced the genome of R.varieornatus, identifying the genes that help the animals tolerate stressful conditions. They found a protein specific to water bears called Dsup (“Damage suppressor”). Dsup allows water bears to survive radiation, including X-ray radiation.
The team then cultured human cells with the Dsup protein and exposed them to X-rays. Amazingly, DNA damage was reduced by 40% and overall radiotolerance was improved. Cells that had been treated with Dsup were more likely to remain viable after being exposed to high levels of radiation.
The research team’s findings show that water bears have unique genes for increasing tolerance to extreme environmental conditions. One gene codes for a protein called Dsup, which was able to protect human cells from X-ray damage. The team plans to investigate more tardigrade-unique proteins, with the hope that some of them can be utilized to protect human cells.
Takuma Hashimoto et al. Extremotolerant tardigrade genome and improved radiotolerance of human cultured cells by tardigrade-unique protein. Nature Communications (2016).