Viruses: The new coronavirus can be hidden in the brains of mice, or it may explain the mystery of the recurrence of COVID-19 patients after recovery

Winter has come, the Spring Festival wants to come.
With the increase in the flow of people, the new coronary pneumonia (COVID-19) outbreak caused by the new coronavirus (SARS-CoV-2) infection appears to have become more serious, with official COVID-19 outbreak figures released every day affecting everyone's hearts! With the joint efforts of researchers around the world, we have gained a deeper understanding of SARS-CoV-2, but little is known about the pathogenesis of its central nervous system (CNS).
is well known that the brain is the central processor of human beings, and COVID-19 can cause diseases of the human nervous system, and exploring its pathology can help people better respond to outbreaks and fight disease.
recently, Viruses published an article entitled Neuroinvasion and Enitis Intranasal Inoculation of SARS-CoV-2 in K18-hACE2 Mice, which found that infection with K18-hACE2 genetically modified mice in sars-CoV-2 in the nose can cause serious neurological diseases.
the path of the nasal passages to the brain is more direct than the mouth, and changes in smell and taste are one of the symptoms of COVID-19, so the researchers inoculated in the nasal cavity of K18-hACE2 mice (n-10) MICE-CoV-2 cells and PBS, infected with SARS-CoV-2 mice began to lose weight significantly on the 4th day, accompanied by drowsiness, slow movement, co-relief disorders, breathing difficulties and other complications, the 6th day of the mouse all died.
suggests that SARS-CoV-2 may infect cells in the nose, eyes and olfactory balls of K18-hACE2 mice, and that the cause of loss of smell caused by certain COVID-19 cases is reasonably explained.
the survival, weight and viral titration analysis of K18-hACE2 mice after SARS-CoV-2 infection, the researchers analyzed the viral load of organs and brains in mice infected with SARS-CoV-2 in the early (day 1), medium (day 3) and late (day 5 and 6) based on qRT-PCR.
found that the amount of virus in the lungs and nasal cavity in mice peaked on the third day and gradually declined on the 5th and 6th days, while the virus in the brain was detected on the 3rd day, reached a higher level on the fifth day, and the highest level of virus in the brain was about 1000 times higher than the highest titration in the lungs, indicating that SARS-CoV-2 has high replication potential in the brain.
virus aphilic analysis in K18-hACE2 mice has a wide spectrum of antiviral functions due to interferon (IFN), which can affect cell growth, differentiation, regulation of immune function and other biological activities.
In further experiments, researchers tested mRNA and protein levels of IFN-α in the lungs and brains of mice and found that ifN-α's mRNA and protein levels in the lungs peaked on day 3 and dropped on day 6, while high levels of IFN-α were detected only on the 5th and 6th days after infection in the brain.
interesting is that although viruses have higher levels of replication in the brain, in the ifN-α perspective, the relative levels in the lungs are higher.
virus infections in the central nervous system that analyze the mRNA and protein levels of interferon-α (IFN-α) in the lungs and brain are usually accompanied by inflammatory responses, such as the production of cytokines/cytokines, based on qRT-PCR on IL-6, IL-1 beta, IFN Tests on -γ, TNF-α, CCL2, and CCL3 found that mice with SARS-CoV-2 infected cytokines and coercion factors expressed far more in the brain than in the lungs, suggesting that inflammatory responses were more pronounced in the brain in the later stages of infection than in the lungs.
the sixth day of infection in mice with cytokines and the tendon mRNA levels in the lungs and brain, researchers detected cell-related viral antigens from parts of the brain, including the cortectal, cer cerebral and hippocellular regions.
results of HE staining and immunological analysis of brain slices showed that neurons in mice shrunk and degenerated, bleeding around blood vessels, and white blood cell immersion increased.
findings explain why some COVID-19 patients have improved lung function, but are likely to relapse and die quickly.
tissue pathology analysis of the brain infected with SARS-CoV-2 found that cells infected with SARS-CoV-2 in the brains of genetically modified mice K18-hACE2 became the virus's favorite hiding place because there was no immune response in the brain.
Although COVID-19 rehabilitation patients appear to have fled THE SARS-CoV-2, they may still face health problems including autoimmune diseases, Parkinson's disease, multiple sclerosis, and general cognitive decline.
, the sly SARS-CoV-2 must not be let down.