Zika Update: This Is How the Zika Virus Causes Microcephaly

A new study from the University of Cambridge, in collaboration with Wellcome Trust, revealed how the Zika virus wreak havoc in the development of children's brains, causing a condition known as microcephaly, which is characterized by an abnormally small head.

The study, published in the journal Science, showed that the Zika virus is capable of hijacking a protein known as Musashi-1 (MSI1). MSI1 is an RNA-binding protein involved in regulating the pool of neural stem cells. By hijacking the MSI1, the Zika virus gains the ability to replicate in and kill neural stem cells.

"We've shown for the first time this interaction between Zika and MSI1 -- with MSI1 getting exploited by the virus for its own destructive life cycle, turning MSI1 into the enemy within," said Dr. Fanni Gergely from the University of Cambridge, in a press release. "We hope that in the future this discovery could lead to ways of generating potential Zika virus vaccines."

To a have a better understanding on how the Zika virus causes microcephaly, the researchers analyzed a variety of cell lines, including human neural stem cells.

The researchers found at least two possible ways on how the Zika virus hijacks MSI1 and use it to replicate and damage stem cells. First, the protein binds with the virus genome. This allows the virus to replicate and make cells more vulnerable to cell death caused by the virus.

In the second way, the virus acts like some sort of "sponge" that prevents the protein from working correctly. The researchers observed that the MSI1 prefers to bind to the virus genome rather than its normal target. Due to this, many genes involved in the normal development of neural stem cells are altered.

In order to confirm their findings, the researchers showed that individuals with inherited microcephaly, which is not related to the Zika virus, have mutated MSI1 protein. This verifies their earlier hypothesis that MSI1 is needed by the neural stem cells in order to generate enough neurons for normal brain cells. However, the presence of this protein increases the vulnerability of the cells to Zika infections, resulting to microcephaly.