Severe COVID-19 is associated with molecular signatures of aging in the human brain

The study “Severe COVID-19 is associated with molecular signatures of aging in the human brain” explores the potential link between severe COVID-19 and accelerated aging in the human brain.

Here’s a detailed summary:

  1. Study Hypothesis and Methods: The study hypothesizes that COVID-19 may lead to molecular signatures similar to aging, focusing on the frontal cortex, a critical area for cognitive function. Researchers performed RNA sequencing on 54 postmortem frontal cortex samples, including those from individuals with severe COVID-19, age-matched and sex-matched uninfected controls, and uninfected individuals with intensive care unit (ICU) or ventilator treatment​​.
  2. Findings on COVID-19 and Brain Aging: The study found that severe COVID-19 is associated with molecular signatures of brain aging. This conclusion is based on the analysis of differentially expressed genes (DEGs) in COVID-19 cases compared to controls. Pathway enrichment analysis revealed significant associations with aging-related pathways, including immune response, synaptic activity, cognition, memory, DNA damage response, mitochondrial function, stress response, oxidative stress, vesicular transport, calcium homeostasis, and insulin signaling​​.
  3. Associations with Cognitive Function: To assess the relationship between COVID-19 and cognitive function, the study analyzed transcriptomic data from individuals who underwent the Mini-Mental State Examination (MMSE) and donated their brains postmortem. They found strong associations between low cognitive performance and COVID-19, suggesting that severe COVID-19 could mimic natural aging processes in the brain​​.
  4. Aging Index Analysis: The study developed an aging index based on aging DEGs and applied it to the COVID-19 cohort. There was a significant increase in the predicted aging index in individuals with COVID-19 compared to uninfected controls, implying that severe COVID-19 could shift the molecular age of the brain​​.
  5. Pathophysiological Mechanisms: The study considered various factors, including SARS-CoV-2 infection and systemic inflammation, as possible causes of the observed gene expression changes. Interestingly, SARS-CoV-2 viral RNA was not detected in the brain samples of individuals with COVID-19, suggesting that the changes might not be due to direct viral effects. Instead, upregulation of pathways related to tumor necrosis factor (TNF) and type I/II interferons was observed, which have been implicated in brain aging and cognitive decline. The study suggests that COVID-19-induced TNF and interferons might lead to deteriorating effects in the brain in the absence of direct viral neuroinvasion​​.

In summary, this study provides evidence that severe COVID-19 is associated with molecular changes in the brain that resemble aging. The findings highlight the importance of neurological follow-up in recovered COVID-19 patients and underscore the potential long-term impact of severe COVID-19 on cognitive function.

Read More: https://www.nature.com/articles/s43587-022-00321-w

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