New Study Suggests Mechanism For Zika-Related Microcephaly

Although scientists have confirmed that the Zika virus can cause microcephaly, they haven't been able to pin down exactly how the virus is able to do so. According to a new study, Zika may be hijacking an essential cellular process in order to spread itself around. For the study, published online today in Cell Stem Cell, researchers looked at the way Zika virus proteins disrupt fetal brain development. They found that two proteins in particular, NS4A and NS4B, alter the way an important molecular pathway functions. Normally, this pathway acts as a sort of resource manager within a cell. One of its jobs is to help activate autophagy, a process that protects a cell by dismantling viral intruders. However, the researchers here found that when Zika is present, those two proteins disrupt this molecular pathway in human fetal neural stem cells. This way, they're able to manipulate the autophagy process to their advantage, using the nutrients involved to replicate the virus rather than destroy it. Down the line, this interrupts the development of neurons and can cause severe neurological issues. Crucially, when the researchers tested the corresponding proteins in the dengue virus, they did not see the same effect. So, they conclude that this is one way Zika sets itself apart from other similar viruses. This discovery isn't going to translate immediately into our fight against Zika and microcephaly, but it's still a pretty big step for our understanding of this complex virus. "We now know the molecular pathway, so we made the first big step toward target therapy for Zika-induced microcephaly," said Jae Jung, PhD, senior author on the study, in a press release. "Years from now, one shot or a series of shots could target the proteins NS4A and NS4B or their collaborators." This would make it so that even if a pregnant woman caught zika, we might be able prevent complications for her fetus. It's also worth noting that not every pregnant person who is infected with Zika gives birth to a baby with microcephaly. So there's still a lot more going on here — and a lot more to uncover.