Bioengineered ‘mini-brain’ suggest human brain cell infection by SARS-CoV-2
Market Expertz | July 02, 2020
A recent study conducted by a multidisciplinary specialist team from two Johns Hopkins University institutions suggests that SARS-CoV-2, the virus that causes COVID-19, infects mini-brain, organoids genetically engineered from human stem cells that stimulate whole organs. The research was carried out by a specialist team of neurotoxicologists, virologists, and infectious disease specialists. Initial reports from Wuhan, China, suggested that neurological symptoms were observed in more than one-third of COVID-19 patients. However, the involvement of SARS-CoV-2 in the observed neurological symptoms was debatable. The team of researchers from the Bloomberg School of Public Health and the School of Medicine has now indicated through their use of ‘mini-brains,’ the expression of ACE2 receptor by numerous human neurons. SARS-CoV-2 exploits this receptor to bind to human cells for entering the lungs, and now possibly the brain.
On the introduction of SARS-CoV-2 virus particles into the mini-brain model, the researchers noted the first evidence of infection by the replication of pathogen. The human brain is strongly protected against toxic pathogens such as viruses and bacteria by the blood-brain barrier. Certain reports suggest that severe inflammation, as observed in COVID-19 patients, can cause disruption of this barrier. However, it is yet to be proven if the SARS-CoV-2 virus crosses the barrier, as noted by Thomas Hartung, Chair for Evidence-Based Toxicology at the Bloomberg School of Public Health. Additionally, the impermeability of the blood-brain barrier could hinder with the drug development process. Although the study has raised concerns pertaining to the impact of SARS-CoV-2 on a developing brain, it provides no evidence of the virus causing developmental disorders. The research findings hint at the need for additional precautions during pregnancy, as ACE2 receptors are observed from the earliest developmental stages in the mini-brain models.
William Bishai, M.D, Ph.D., Professor of Medicine, Johns Hopkins University School of Medicine, believes that the study could be a pivotal step in understanding the infection and the path of drug treatment for the COVID-19 infection. The research findings have recently been published in the journal ALTEX: Alternatives to Animal Experimentation.