Oxidative damage (brown) in placental tissues from mice with a model of preeclampsia M. NEZU ET AL., SCIENCE SIGNALING (2017)As many as 8 percent of pregnant women develop a condition known as preeclampsia, a spike in blood pressure characterized by the reduced formation of placental blood vessels. Previous research has suggested that reactive oxygen species (ROS) may play a role in triggering the untreatable condition, which causes up to 15 percent of maternal deaths and 5 percent of stillbirths globally. A handful of clinical trials have even attempted to reduce the risk of preeclampsia by targeting ROS accumulation, but treated women often had worse outcomes. Now, a study in mice published today (May 16) in Science Signaling provides a potential clue as to why: ROS may actually help protect against preeclampsia by increasing blood vessel generation in the placenta.
The results “were exactly opposite” of what the researchers had expected, coauthor Norio Suzuki, a molecular biologist at the Tohoku University Graduate School of Medicine in Japan, told The Scientist in an email. Earlier work had shown that in preeclampsia patients, ROS pile up in their placentas. “However, data from this study indicated that ROS accumulation induces placental angiogenesis in a preeclampsia mouse model and improves maternal and fetal outcomes,” he said.
Using genetically modified mice, Suzuki and his colleagues recently discovered that the Keap1-Nrf2 pathway, which induces the expression of detoxification and antioxidant enzymes, “is essential for protection of organs from damages in many types of diseases,” he explained. This led the researchers to wonder whether the system might also be involved in preeclampsia.
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