Just 13 days in space may be enough to cause profound changes in eye structure and gene expression, scientists have found.
Researchers from Houston Methodist Hospital , Nasa Johnson Space Center, and other institutions looked at how low gravity and radiation and oxidative damage impacts mice.
Researchers from Houston Methodist Hospital , Nasa Johnson Space Center, and other institutions looked at how low gravity and radiation and oxidative damage impacts mice.
"We found many changes in the expression of genes that help cells cope with oxidative stress in the retina, possibly caused by radiation exposure," said Houston Methodist pathologist Patricia Chevez-Barrios , the study's principal investigator. "These changes were partially reversible upon return to Earth. We also saw optic nerve changes consistent with mechanical injury, but these changes did not resolve. And we saw changes in the expression of DNA damage repair genes and in apoptotic pathways, which help the body destroy cells that are irreparably damaged," she said.
To determine the impact of radiation exposure on eyes, Chevez-Barrios and lead author Susana Zanello, a space life scientist at NASA Johnson Space Center, examined mouse retinal gene expression on the 1st, 5th, and 7th days following a 13-day trip aboard space shuttle Discovery (STS-133 ), measuring indicators of oxidative and cellular stress.
Mice returning to Earth showed immediate evidence of oxidative stress in their retinas . But the increased expression of six oxidative stress response genes appeared to return to normal by the seventh day on Earth. An indicator of oxidative stress in the cornea was also elevated one day after mice had returned from orbit, but returned to near-normal levels by the seventh day.
To determine the impact of radiation exposure on eyes, Chevez-Barrios and lead author Susana Zanello, a space life scientist at NASA Johnson Space Center, examined mouse retinal gene expression on the 1st, 5th, and 7th days following a 13-day trip aboard space shuttle Discovery (STS-133 ), measuring indicators of oxidative and cellular stress.
Mice returning to Earth showed immediate evidence of oxidative stress in their retinas . But the increased expression of six oxidative stress response genes appeared to return to normal by the seventh day on Earth. An indicator of oxidative stress in the cornea was also elevated one day after mice had returned from orbit, but returned to near-normal levels by the seventh day.