In addition to the respiratory problems caused by COVID-19, doctors and researchers have already identified a series of symptoms in patients infected with the new coronavirus (SARS-CoV-2), such as loss of smell and taste, mental confusion, stroke and even muscle pain. Now, scientists at the State University of Campinas (Unicamp) warn of the ability of this virus to infect human neurons.
The hypothesis was confirmed by the real-time PCR exam, which is the same method used in the diagnosis of COVID-19 in laboratories and hospitals. For testing outside the laboratory, health professionals collect the respiratory secretion of the suspected patient and perform direct virus detection.
Through experiments carried out with cell culture in the laboratory, the group of Brazilian researchers, coordinated by the professor of the Institute of Biology Daniel Martins de Souza, continues to investigate how infection and the increase in viral load in nerve cells can affect the functioning of this system.
In laboratory tests, Brazilian researchers identify that the new coronavirus can affect human neurons (Photo: Matthias Friel / Adobe Stock)
According to the first steps of the study, it is already known that neurons express the protein ACE-2 (angiotensin-converting enzyme 2), and it is through this molecule that the coronavirus connects to invade human cells.
In the coming days, Unicamp scientists will investigate how the functioning of these nerve cells is altered by infection with the new coronavirus. “We are going to compare the proteins and other metabolites present in cell cultures before and after infection. The idea is to observe how the pattern of the molecules changes and, based on this information, try to tell the story of how the virus acts in the central nervous system ”, explains Martins de Souza to Agência FAPESP.
In the experiment, already carried out by postdoctoral fellow Fernanda Crunfli to confirm the infection in neurons, the contamination was induced in a human brain cell line, in addition to human neurons obtained from stem cells.
“We are also starting tests with human astrocytes [células do sistema nervoso que sustentam e nutrem os neurônios] and, soon, we will know if the virus infects these cells, which support the functioning of neurons and are the most abundant in the central nervous system ”, explains the professor.
Effects on the brain
According to Daniel Martins de Souza, other studies had already suggested that this coronavirus would have a certain propensity to infect nerve cells. “But we still don’t know if the virus really can cross the blood-brain barrier [estrutura que protege o cérebro de substâncias tóxicas e patógenos presentes na circulação sanguínea] and, if so, what kind of impact it can have on nerve tissue. We will try to look for clues that help to clarify these doubts ”, he argues.
“In addition to investigating whether the amount of a given protein in the sample increases or decreases after infection, we also intend to assess how the level of phosphorylation and glycosylation of the molecules is. These two biochemical mechanisms are used by the cell to quickly activate or deactivate the function performed by proteins. This will give us clues about the metabolic pathways that are altered in neurons in response to the new coronavirus ”, concludes the Unicamp researcher.
The research in question is conducted as part of a project approved by FAPESP in the so-called “Supplements for Rapid Implementation against COVID-19”. To combat the epidemic in Brazil, the study integrates a task force created by Unicamp.
Source: Fapesp Agency