Difficult COVID-19 looks scary like age in the human brain, according to a post-mortem of 54 healthy and infected people.
The study authors say their research is the first to link COVID-19 to molecular signatures of brain aging.
“We observed that gene expression in the brain tissue of patients who died from COVID-19 is very similar to that of uninfected individuals aged 71 years or older.” says Harvard University health scientist Jonathan Lee.
The sample, composed of people in their early twenties to mid-eighties, includes 21 people with severe COVID-19, a single asymptomatic person, and 22 people who were not infected with the Coronavirus.
The researchers also compared their findings to those of an uninfected person Alzheimer disease and another group of 9 uninfected individuals with a history of hospitalization or ventilator treatment.
Using RNA sequencing technology on prefrontal cortex samples, scientists found that those with severe COVID-19 showed enriched genetic expression patterns associated with aging.
The brains of infected people looked more similar to older people in the control group, regardless of their actual age.
Put simply, genes that were normally upregulated with age, such as those in the immune system, were also upregulated during severe COVID-19.
At the same time, genes that are downregulated in old age, such as those related to synaptic activity, cognition, and memory, were also downregulated in severe COVID-19.
“We also observed significant associations of cellular response to DNA damage, mitochondrial function, regulation of stress and oxidative stress response, vesicular transport, calcium homeostasis, and insulin signaling/secretion pathways previously associated with aging and brain aging in have been linked,” the authors said write.
“Taken together, our analyzes suggest that many biological signaling pathways that change with natural aging in the brain also change during severe COVID-19.”
Since the novel coronavirus SARS-CoV-2 began infecting people worldwide, scientists feared possible long-term effects.
One of the most problematic consequences is damage to the brain. Severe cases of COVID-19 are often connected with brain fog, memory loss, stroke, delirium, or coma. In October 2020, first brain scans in COVID-19 patients showed worrying signs of neurological disorder and impairment.
Later Studies meanwhile found even mild COVID-19 can affect the brain, although it’s not yet clear how long these changes last or how they compare to those with severe COVID-19.
With each passing year, health experts have a slightly better idea of the long-term outcomes this global trend is having Pandemic could bring. Three years later, things are not looking good.
The results of the current study follow a different one paperwhich was published earlier this year and found that the cognitive effects of severe COVID-19 correspond to about 20 years of aging.
Neuropathologist Marianna Bugiani from the University of Amsterdam said Nature The new findings raise “a wealth of questions that are important not only to understand the disease, but to prepare society for the possible consequences of the pandemic”.
She also added that these consequences may not be clear for many years to come. And by that time, the global community is likely to suffer repeated COVID-19 infections.
Who knows how multiple diseases will affect our cognitive performance in the long term?
Interestingly, the researchers found no genetic evidence of SARS-CoV-2 in the current study virus in the brains of infected patients, suggesting that the neurological sequelae of the virus may not be directly attributable to their presence in the nervous system.
However, the authors found evidence of this tumor necrosis factor (TNF), which is linked to inflammation, brain aging and age-related cognitive decline, was present at higher levels in the brains of infected individuals.
Genetic factors associated with antiviral immune responses were also increased.
the authors to quarrel Both pathways “can result in significant brain deterioration without SARS-CoV-2 neuroinvasion.”
Given their findings, the team says people recovering from COVID-19 should have neurological follow-up exams. If the mere presence of this novel virus is enough to trigger inflammation in the brain, it’s possible that anyone infected is at risk of brain deterioration.
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 use and exercise.
It’s probably also a good idea to do your best to avoid future COVID-19 infections.
The study was published in aging in nature.
