Reactive Oxygen Species Help Tadpoles Heal

Reactive oxygen species (ROS) such as hydrogen peroxide have long been notorious for causing harm to cells. A new study, however, suggests that these compounds might not be so bad after all. A research team, led by Enrique Amaya of the University of Manchester, in England, has demonstrated that tadpoles need ROS to regenerate their tails (Nat. Cell Biol., DOI: 10.1038/ncb2659). Understanding how much ROS is good or bad for cells and how the tadpoles regulate ROS levels could help scientists eventually improve tissue healing and regeneration in humans, Amaya says. To show the importance of ROS, the researchers first genetically engineered tadpoles to produce a protein that shifts its fluorescence when oxidized by compounds like hydrogen peroxide. After they amputated the tadpoles’ tails, they found high concentrations of ROS in the regrowing tissue, as measured by fluorescence imaging. The team also demonstrated that tail regeneration can’t proceed without ROS. When the researchers exposed amputated tadpoles to both an antioxidant, which scavenges ROS, and compounds such as apocynin, which prevent the enzyme NADPH oxidase from generating ROS, tail regrowth was stunted.