Thanks to fungi, researchers have made a new discovery that could lead to the development of effective radioprotective drugs for workers cleaning up nuclear contamination zones, like Fukushima and Chernobyl. The discovery could also help astronauts travel to mars, where severe radiation remains the greatest obstacle.
The study, "Chronic Gamma Radiation Resistance in Fungi Correlates with Resistance to Chromium and Elevated Temperatures, but not with resistance to acute radiation," was published Aug. 6 in Scientific Reports. It was led by researchers at the Uniformed Services University of the Health Sciences (USU) in collaboration with the Center for Radiological Research at the Columbia University Irving Medical Center, Center for Radiological Research.
For years, scientists have been trying to develop effective radioprotective drugs that would counter the harmful effects of radiation for people exposed to high levels over a long time, for example, following acts of terrorism, clean-up of a nuclear power plant accident, or for astronauts on long-duration deep space exploration missions. Scientists, working on these countermeasures, have generally assumed that human cells react the same way to sudden acute doses of radiation as they do to continuous prolonged exposure, explained Dr. Michael Daly, a pathology professor at USU and the study's senior author.
Having studied radiation-resistant micro-organisms for the last 30 years, Daly and his team already knew yeasts and other types of fungi react to radiation much like human cells because they are both made up of cells in which the genetic material is DNA, made up of chromosomes. They also share many common physiological and genetic mechanisms. Therefore, they focused their efforts on studying these yeasts – 95 different strains to be exact. They analyzed the ability of these yeasts to resist gamma radiation over time, in comparison to how they survived one acute blast. What they discovered was the cells did not cope with different radiation exposures the same way. The researchers believe that understanding the mechanisms for these responses to radiation could be translated to how human cells respond to radiation over time.
We were surprised by these findings, since it has long been assumed that cells react similarly to sudden acute doses of radiation as they do to continuous exposure over time. We're excited about the implications these findings could have for future Mars astronauts and for those responsible for nuclear waste cleanup."
Dr. Michael Daly, pathology professor, USU
This project was supported by a Defense Threat Reduction Agency (DTRA) grant to Dr. Daly. The team also included scientists at the Center for Radiological Research at the Columbia University Irving Medical Center, the Department of Biology, University of Bielefeld, Bielefeld, Germany, and the Institute of Medicine and Psychology, Novosibirsk State University, Novosibirsk, Russia.
Shuryak, I. et al. (2019) Chronic gamma radiation resistance in fungi correlates with resistance to chromium and elevated temperatures, but not with resistance to acute irradiation. Scientific Reports. doi.org/10.1038/s41598-019-47007-9.