Researchers from the University of Texas Medical Branch at Galveston have revealed in a study how the Zika virus is able to alter fetal brain development and cause microcephaly.
Published in the journal Stem Cell Reports, the study results may help shed light on how Zika causes birth defects.
Zika And Microcephaly
At the moment, 70 countries and territories around the world are dealing with active transmissions of the Zika virus, based on data from the World Health Organization. While an infection in healthy children and adults usually leads to mild or even symptom-free sickness, those yet to be born are at high risk of microcephaly, which can in turn lead to a host of other health problems for the child, such as hearing and vision loss, feeding difficulty, seizures, and developmental delays.
Researchers like Erica McGrath and colleagues wanted to know how exactly Zika causes these defects. Given the brain normally develops from stem cells that then develop into more specialized cells, the researchers for the current study deduced that microcephaly is likely to be associated with abnormal stem cell activity.
Recently, the same team of researchers discovered that the Asian lineage of the Zika virus is tied to microcephaly cases. The virus has two main lineages: Asian and African.
Zika And Brain Development
What is it about the Asian form of the virus then that particularly leads to such kind of damage? According to the researchers, it has to do with how Zika alters how brain stem cells are produced, survive, and mature.
"We discovered that the Asian lineage Zika virus halted the proliferation of brain cells and hindered their ability to develop into brain nerve cells," said senior author Ping Wu.
However, he added that how Zika affected stem cell development varied between the samples they used, which were sourced from three human fetal brains. The variations, Wu said, appears to have links with changes the virus induced in global gene expression pattern but it remains to be seen which genes exactly are responsible.
With their findings, the researchers are of the belief that the stem cell samples will pave the way for the virus' molecular mechanisms related to brain malformations to be dissected. Based on their results, they observed that two weeks after stem cells developed into more specialized types, the Zika virus was identified mostly in glial cells, which are cells tasked with supporting and insulating the brain.
Nikos Vasilakis, Scott Weaver, Ildefonso Fernandez-Salas, Yongja Yu, Thomas Wood, Bradford Loucas, Deborah Prusak, Ying Xiong, Christopher Roundy, Sasha Azar, Tiffany Dunn, Auston Grant, Steven Widen, Junling Gao, and Shannan Rossi also contributed to the study.
Zika And Other Health Risks
According to experts at the Climate & Health Meeting in Atlanta, which replaced the climate change conference the U.S. Centers for Disease Control and Prevention had set and postponed, the climate crisis poses a threat to public health as it makes way for more disease outbreaks, massive food shortages, and fatal heat waves. Warmer temperatures could endanger public health as they are conducive to mosquitoes, which can transmit a number of viruses, including Zika.