COVID Accelerates ‘Zombie’ Cells in Brain, Study Says

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COVID-19 is accelerating the accumulation of senescent or “zombie” cells in the brain, which accumulate naturally and gradually in the brain with ageing, according to a new study from the University of Queensland.

The researchers used brain organoids—mini brains artificially grown from human stem cells—to study this effect.

They discovered that SARS-CoV-2, the virus causing COVID-19, infects the brain, triggering cellular senescence, a process that causes premature ageing of the brain.

“Senescent cells are known to drive tissue inflammation and degeneration, leaving patients exposed to cognitive impairments like brain fog and memory loss,” lead researcher Julio Aguado said.

Brain fog refers to a loss of the ability to concentrate or remember, issues thinking, and a feeling of drowsiness.

Brain Cell Fusion

A study published in Science Advances earlier this year also found that SARS-CoV-2 led to the fusion of brain cells, which can result in chronic symptoms in the nervous system.

“We discovered COVID-19 causes neurons to undergo a cell fusion process, and once neurons fuse, they don’t die,” said Massimo Hilliard, a professor of molecular and cellular neurobiology at the University of Queensland.

“They either start firing synchronously, or they stop functioning altogether.”

The researchers said that this novel mechanism may explain the neuropsychiatric syndromes associated with early-stage COVID-19 and the persistence of symptoms in long Covid.

‘Vaccine Fog’

People who have never had COVID-19 but have received doses of the COVID-19 vaccines have also reported symptoms of brain fog, headaches, and memory problems.

Since SARS-CoV-2 can induce various types of brain damage, the vaccines—which contain synthetic mRNA based on the virus’s genetic sequence—might have similar effects, explained Dr. Yuhong Dong, an infectious disease and antiviral drug development expert.

She emphasised the self-repairing ability of the human body, recommending that the three best ways to repair brain injuries, whether it be from vaccines or COVID-19, are to control the intake of sugary foods, prioritise high-quality sleep, and maintain a healthy attitude.

“The human body is a sophisticated, complex, and self-maintaining and repairing system created by God,” she said.

“It has its own rules of operation, and has the ability to protect itself from foreign viruses. It has the ability to self-recover under the inducement of disease.”

Therapies to Target ‘Zombie’ Cells

In addition, Mr. Aguado’s research team has developed new therapies to target senescent cells specifically.

They identified four drugs that can eliminate these zombie cells—navitoclax, ABT-737, fisetin, and a cocktail of dasatinib plus quercetin (D+Q).

Mr. Aguado said the drugs rejuvenated the brain and decreased the chance of neurodegenerative symptoms in the organoids, as well as in a mouse model infected with COVID-19.

“Long term, we can expect widespread use of these drugs to treat persistent post-acute infection syndromes caused by viral infections like COVID-19,” he said.

However, further research is needed to understand the underlying mechanisms, Mr. Aguado said.

“More research is needed to fully understand the mechanisms at play, but this study marks a significant step forward in our knowledge of the intricate relationship between viral infections, aging, and neurological well-being,” he said.

Organoid expert Professor Ernst Wolvetang suggests that stem-cell-derived brains can potentially treat post-acute infection syndromes and neurodegenerative diseases such as Parkinson’s disease.

“This same method of drug screening could also help Alzheimer’s research and a whole host of neurodegenerative diseases where senescence is a driver,” Mr. Wolvetang said.