Gene usage in the brains of patients with COVID-19 is similar to that seen in aging brains, according to experiments conducted by scientists at Beth Israel Deaconess Medical Center (BIDMC).
Scientists emphasize the value of neurological monitoring in recovered individuals.
It is true that COVID-19 is primarily a respiratory disease. However, neurological symptoms have been described in many patients with COVID-19, even in recovered individuals. In fact, patients have reported a range of symptoms such as brain fog or lack of focused thinking, memory loss and depression. In addition, scientists have shown that patients with severe COVID-19 show a decline in cognitive performance that mimics accelerated aging. But what has been lacking is molecular evidence of the aging effects of COVID-19 on the brain.
In a series of experiments, scientists discovered that gene usage in the brains of patients with COVID-19 is similar to that seen in aging brains. The scientists, from Beth Israel Deaconess Medical Center (BIDMC), used a molecular profiling technique called RNA sequencing to measure the levels of each gene expressed in a particular tissue sample. This allowed them to assess changes in gene expression profiles in the brains of patients with COVID-19 and compare them to changes seen in the brains of uninfected individuals. The team’s analysis suggested that many biological pathways that change with natural brain aging also changed in patients with severe COVID-19. The study was published Dec. 5 in the journal Nature Aging.
US COVID Data Tracker
- New cases per week: 458,986
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- Total deaths: 1,080,472
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- Current hospitalizations: 30,252
CDC data as of December 9, 2022.
“Ours is the first study to show that COVID-19 is associated with molecular signatures of brain aging,” said co-author Maria Mavrikaki, PhD, instructor of pathology at BIDMC and Harvard Medical School. . “We found striking similarities between the brains of patients with COVID-19 and older individuals.”
Mavrikaki and colleagues analyzed a total of 54 postmortem human frontal cortex tissue samples from adults aged 22 to 85 years. Of these, 21 samples were from severe patients with COVID-19 and one from an asymptomatic patient with COVID-19 who died. These samples were age- and sex-matched to uninfected controls with no history of neurological or psychiatric disease. The scientists also included an age- and sex-matched uninfected Alzheimer’s disease case for the analysis as a control for a COVID-19 case that had comorbid Alzheimer’s disease, as well as a control group additional independent of uninfected individuals with a history of intensive treatment. care or treatment with ventilation.
“We observed that gene expression in the brain tissue of patients who died of COVID-19 closely resembled that of uninfected individuals aged 71 and older,” said co-author Jonathan Lee, PhD, a postdoctoral researcher at BIDMC and Harvard Medical. school “Genes that were upregulated in aging were upregulated in the context of severe COVID-19; similarly, genes downregulated in aging were also downregulated in severe COVID-19. Although we found no evidence that the SARS-CoV-2 virus was present in brain tissue at the time of death, we discovered inflammatory patterns associated with COVID-19, suggesting that this inflammation may contribute to the disease-like effects aging observed in the brains of patients with COVID-19 and long-term COVID-19”.
“Given these findings, we advocate neurologic monitoring of recovered patients with COVID-19,” said lead and co-corresponding author Frank Slack, PhD, director of the Institute of RNA Medicine at BIDMC and professor of ‘medical research by Shields Warren Mallinckrodt. at Harvard Medical School. “We also emphasize the potential clinical value of modifying factors associated with dementia risk, such as controlling weight and reducing excessive alcohol consumption, to reduce the risk or delay the development of age-related neurological pathologies and cognitive impairment”.
A better understanding of the molecular mechanisms underlying brain aging and cognitive decline in COVID-19 could lead to the development of new therapeutics to address the cognitive decline observed in patients with COVID-19. The team is now trying to understand what causes the aging-like effects in the brains of patients with COVID-19.
Reference: “Severe Covid-19 is associated with molecular signatures of aging in the human brain” by Maria Mavrikaki, Jonathan D. Lee, Isaac H. Solomon, and Frank J. Slack, December 5, 2022, Nature Aging.DOI : 10.1038/s43587 -022-00321-w
Isaac H. Solomon, MD, PhD, of Brigham and Women’s Hospital, also contributed to this work, which was supported by the National Institute on Aging (NIA; R01 AG058816). The authors declare that there are no conflicts of interest.