A double-edged sword
When tissues are deprived of blood, as happens during a stroke or heart attack, the lack of oxygen can cause serious damage. After blood flow is restored, further damage occurs as the tissues become inflamed. This process, known as ischemia/reperfusion, also occurs during organ transplantation, and can induce widespread cell death. A new study from MIT biological engineers shows that surprisingly, a DNA-repair enzyme called Aag actually makes this damage worse. Mice lacking this enzyme show much less tissue damage from ischemia/reperfusion than normal mice, suggesting that blocking this enzyme could be beneficial for patients who have strokes, heart attacks, or organ transplants. “The exciting thing about this finding is that it is relevant to so many different diseases and conditions,” says Leona Samson, the Uncas and Helen Whitaker Professor in the departments of Biological Engineering and Biology, and a member of MIT’s Center for Environmental Health Sciences and Koch Institute for...