Zika virus is a virus that damages the brain and causes malformation. Studies showed that virus is more partial towards a certain type of neural cells i.e. astrocytes. Some studies are conducted to identify the effects of the virus on these cells and developmental alternations caused by it such as microcephaly and brain malformations.
A new article is published in Scientific Reports which shows the effect of the virus on laboratory-created astrocytes. The artificially created astrocytes are then compared to astrocytes of the brain from the tissue of an animal that is infected with the Zika virus.
Astrocytes are named after the Greek word for stars due to their branched tipped structure. Astrocytes are an abundant type of cells present in human brain tissue. The astrocytes provide metabolic support to neuron cells. It has a role in the formation of synapses and also the part of the blood-brain barrier. It is the structure of the brain that limits the harmful substances from entering into the brain.
D’Or Institute for Research and Education (IDOR) conducted a study in collaboration with the Federal University of Rio de Janeiro (UFRJ) and other Brazilian institutes. Researchers found that the Zika virus produced neural complications and some of them are linked with astrocytes damage, which will further cause the malformations of the brain.
Steven Rehen was a neuroscientist and is the author of the article. He is involved in many studies related to the Zika virus to study the effects of the Zika virus in the laboratory creates mini-brains. Rehen and his team disclosed that the Zika virus infection in the developing neural cells and induces alternations in brain development.
A member of Rehen’s group and one of the authors of the study, Karina Karmirian said scientific literature shows that the Zika virus damages astrocytes but still no study is designed to focus on the mechanism of its damage that causes malformation of the brain. The virus brings alternations in the cells and cells become overload with mitochondria, oxidative stress, and DNA breakage. Oxidative stress is most common in premature aging, neurodegenerative diseases, and cancer.
Scientists created three types of brain cells in the laboratory such as Astrocytes, neural stem cells, and neurons. Cells are then infected with the Zika virus and most severe damage is seen in astrocytes. The mitochondria of astrocytes start to produce free radicals in an excess amount which generates oxidative stress. Due to it, the morphology of brain changes. Infections cause the death of many cells but those who survive after the infections have irregular nuclei.
Scientists identified the patterns of Zika virus attack and found inflammation signs in the fetal astrocytes. Similar signs of inflammation have also observed in animals. Mice with Zika virus infection show greater damage to astrocytes in the brain as compared to neurons. The microglial cells similar to astrocytes in providing support to neurons also get an infection
The cells provide immunity to the brain. Inflammation has been seen in astrocytes during the experiments. As the neurons depend on the astrocytes and microglia for healthy performance so it is assumed that in long-term neurons would be affected due to Zika virus infection.
The study concludes that astrocytes are required for normal brain growth and function, but their imbalance induces many complications related to the brain throughout life. The complications are not only linked to malformations or microcephaly, but it could lead to many neurological disorders. Further investigations are needed to check the effect of the Zika virus in children and adults.