Over the last few months, the Zika virus has been making headlines, particularly since infection during pregnancy has been linked to a serious birth defect known as microcephaly, in which infants are born with unusually small heads.
Because of these concerns, in February of this year, the World Health Organization declared Zika virus a Public Health Emergency of International Concern and indicated that more research was needed to investigate and better understand the relationship between the virus and microcephaly.
While some researchers are using animal models—including mice and nonhuman primates—to investigate Zika virus infection, scientists from Johns Hopkins University and other collaborating labs decided to take a more human-relevant and cost-effective non-animal approach.
Human-induced pluripotent stem cells were used to create three-dimensional brain organoids inside spinning bioreactors. These organoids were able to mimic many key aspects of human embryonic brain development. They were then used to examine the impact of Zika virus exposure at different stages of pregnancy.
Researchers determined that specialized stem cells in the 3-D model were particularly sensitive to Zika virus infection. They also discovered that exposure of the brain organoids to the Zika virus for just one day led to detrimental effects resembling what is seen in cases of microcephaly. Specifically, the organoids showed increased cell death and a suppressed ability to proliferate, which resulted in a decreased neuronal cell-layer volume and smaller size.
According to the study’s authors, “Forebrain organoids therefore provide a quantitative experimental platform for future studies to investigate the impact of ZIKVs [Zika viruses], identify cellular and molecular mechanisms, and screen for therapeutic interventions, issues that are critical to resolving the current global health emergency related to ZIKV.”
The brain organoid model represents a versatile and human-relevant platform to study brain development “that cannot be represented in rodent models,” according to the study’s authors. They note that the model will also be useful for studying disease and testing drugs.
We are excited about the impact this promising tool will have in these areas of research, as well as the plans researchers have to further optimize the model and use it to test drugs to see if they offer protection against Zika virus infection.
What are your thoughts on the use of non-animal models such as human organoids for studies of Zika virus exposure? Send your questions and comments to firstname.lastname@example.org. We look forward to hearing from you.
Mini Brains Model Zika Infection
April 22, 2016
Researchers create cerebral organoids in 3-D–printed bioreactors that can be used to model Zika infection.
For more information: The Scientist
Brain-Region-Specific Organoids Using Mini-bioreactors for Modeling ZIKV Exposure
May 19, 2016[O]ur brain-region-specific organoids and SpinΩ provide an accessible and versatile platform for modeling human brain development and disease and for compound testing, including potential ZIKV antiviral drugs.
For more information see: Cell