Severe COVID-19 looks eerily similar to aging in the human brain, according to a post-mortem study of 54 healthy and infected people.
The study’s authors say their research is the first to link COVID-19 with molecular signatures of brain aging.
“We observed that gene expression in brain tissue from patients who died of COVID-19 closely resembled gene expression in infected individuals aged 71 or older,” says Harvard University public health scientist Jonathan Lee.
The sample, made up of people in their early twenties to mid-eighties, included 21 people with severe COVID-19, a single person with no symptoms, and 22 people who were not infected with the coronavirus.
The researchers compared their results with an infected person with Alzheimer’s disease and another group of nine infected people with a history of hospitalization or ventilator therapy.
Using RNA sequencing technology on samples from the prefrontal cortex, the scientists found that those with severe COVID-19 showed enriched gene expression patterns associated with aging.
The brains of the infected individuals were similar to those of older individuals in the control group, regardless of their actual age.
Simply put, genes that are normally up-regulated in aging, like those associated with the immune system, were up-regulated in severe COVID-19.
At the same time, genes that are reduced during aging, such as synaptic activity, cognition and memory, were also reduced in severe COVID-19.
“We also observed significant associations between cellular response to DNA damage, mitochondrial function, stress response and regulation of oxidative stress, vesicular transport, calcium homeostasis, and insulin signaling/secretory pathways with aging processes and brain aging,” the authors write. . .
“Altogether, our analyzes suggest that many of the biological pathways that change with natural aging of the brain also change in severe COVID-19.”
Ever since the novel coronavirus SARS-CoV-2 began infecting humans on a global scale, scientists have feared the long-term consequences.
Brain damage is one of the most problematic outcomes. Severe cases of COVID-19 are often associated with brain fog, memory loss, stroke, confusion, or coma. In October 2020, preliminary brain scans of COVID-19 patients revealed worrisome signs of neurological damage and weakness.
Subsequent studies have found that even milder COVID-19 affects the brain, but it’s still unclear how long these changes last or how they compare to severe COVID-19.
With each passing year, health experts have a slightly better idea of the long-term effects this global epidemic may bring. In three years, it’s not good.
The current study’s findings come on the heels of another paper published earlier this year, which found that the cognitive impact of severe COVID-19 is equivalent to about 20 years of aging.
said Mariana Bugiani, a neuroscientist at the University of Amsterdam nature The new findings open up “a host of questions that are important not only for understanding the disease, but also for preparing society for what the consequences of the pandemic may be.”
She also said that these consequences may not be evident for many more years. By this time, the global community was suffering from repeated COVID-19 infections.
Who knows how multiple diseases affect our cognitive abilities in the long run?
Interestingly, in the current study, the researchers did not find genetic evidence of the SARS-CoV-2 virus in the brains of infected patients, suggesting that the neurological effects of the virus may not be directly due to their presence in the nervous system.
However, the authors found evidence of higher levels of tumor necrosis factor (TNF), which is associated with brain inflammation, brain aging and age-induced cognitive decline in infected individuals.
Genetic factors associated with antiviral immune responses have also been elevated.
The authors argue that both of these pathways “can exert significant degenerative effects in the brain in the absence of SARS-CoV-2 neuroinvasion.”
Based on their findings, the team says people recovering from COVID-19 should receive neurological follow-up. If the presence of this new virus is enough to cause brain inflammation, any infected person could be at risk of brain damage.
Until experts know more, the authors say, doctors and patients should focus on other risk factors for dementia that are within our control, such as weight, alcohol consumption and exercise.
It’s also a good idea to do your best to prevent future COVID-19 infections.
The study was published in Aging in nature.