New research published in the journal Nature Neuroscience reveals alarming insights into the true damage caused by COVID-19 on an infected person’s body. A collaborative effort between researchers from Germany, France, and Spain, successfully showed COVID-19’s capability to destroy cells in the brain known as cerebrovascular endothelial cells.
These cells, known in general as endothelial cells, form the internal walls of blood vessels all over the body, known as the endothelium. They are thus crucial in the distribution of oxygen and other nutrients across the body through the blood. Killing off these cells means severely impacting the performance of these blood vessels, restricting blood flow to these parts of the body.
This new finding comes as the latest in a long line of findings about the current pandemic that has swept through the world. Earlier research into the SARS-CoV-2 virus has revealed how it entered cells in our bodies, as well as showcase just how dangerous the new dominant variants of COVID-19 really are. And while new medicines are being developed to fight against COVID-19, much like the recently-developed Mulnopiravir by pharmaceutical company Merck, it nevertheless remains a priority for researchers to identify the extent of the damage the widespread infection imparts on the people it infects.
This particular study, however, actually gathered its findings by analyzing the brains of patients who had died from the pandemic’s virus. There, they found the presence of string vessels in the brains of these corpses, which are remnants of capillaries with no endothelial cells inside them; thus, these vessels are incapable of carrying blood—leading the team to the conclusion that COVID-19 somehow also restricted blood flow to the brain, too.
Their startling findings correspond to data suggesting that around 84% of COVID-19 patients suffer from neurological symptoms, like confusion, epileptic seizures, and anosmia, or the loss of sense of taste and smell.
As explained by co-author and neuroscientist Jan Wenzel on a Twitter thread: “Having clinical data in mind that hints at microvascular changes in COVID-19 patients, we started to look into the microvasculature of brain samples in deceased COVID-19 patients. We found an increased amount of dead capillaries, so-called string vessels.”
Wenzel and team then showed just how the SARS-CoV-2 virus does this by testing their hypothesis on cell and animal experiments, leading them to their conclusion regarding blood flow restriction to pertinent organs like the brain.
“[We] think that the direct infection of brain endothelial cells by SARS-CoV-2 leads to the expression of its main protease which cleaves NEMO, an essential protein necessary for the survival of brain endothelial cells. Our finding might explain at least partially neurological symptoms that not only appear during the acute but also long-term phase of COVID-19 including the increased risk for getting stroke or epileptic seizures […].”
The team remains positive, however, that the effects of COVID-19 in the brain of this manner are reversible, as demonstrated by mouse models. Wenzel and team also speculate that vaccination can mitigate most of the deleterious effects of COVID-19 to the blood-brain barrier.
Wenzel followed: “As far as we know vaccination protects against the vascular damage since the immune system acts against the virus in our blood, from where endothelial cells are infected.”
In another statement to news outlet RFI News, co-author and Inserm research institute researcher Vincent Prévot mentioned that similar effects from the virus are reversible in hamster models, so they “hope that it could also be reversible in humans.”
References
- Brown, W. R. (2010). A review of string vessels or collapsed, empty basement membrane tubes. Journal of Alzheimer’s Disease : JAD, 21(3), 725–739. https://doi.org/10.3233/JAD-2010-100219
- Coffey, D. & RFI. (2021, October 22). EU scientists reveal long-term brain damage caused by Covid. RFI. https://www.rfi.fr/en/france/20211022-eu-research-reveals-long-term-brain-damage-caused-by-covid
- Haridy, R. (2021, October 25). Study reveals how COVID-19 can directly damage brain cells. New Atlas. https://newatlas.com/health-wellbeing/coronavirus-damage-blood-brain-barrier-cells-cognitive-long-covid/
- Kossoff, J. (2021, October 24). New study finds that COVID-19 can damage brain cells, impairing cognitive function. Business Insider. https://www.businessinsider.com/covid-19-can-kill-brain-cells-impairing-cognitive-function-study-2021-10
- Kossoff, J. & Business Insider. (2021, October 24). Covid-19 can damage blood vessels in the brain, causing neurological symptoms. ScienceAlert. https://www.sciencealert.com/study-finds-covid-19-can-damage-specific-brain-cells
- Wenzel, J., Lampe, J., Müller-Fielitz, H., Schuster, R., Zille, M., Müller, K., Krohn, M., Körbelin, J., Zhang, L., Özorhan, Ü., Neve, V., Wagner, J. U. G., Bojkova, D., Shumliakivska, M., Jiang, Y., Fähnrich, A., Ott, F., Sencio, V., Robil, C., … Schwaninger, M. (2021). The SARS-CoV-2 main protease Mpro causes microvascular brain pathology by cleaving NEMO in brain endothelial cells. Nature Neuroscience, 1–12. https://doi.org/10.1038/s41593-021-00926-1
- Wenzel, J. [@NeuroVascWenz]. (2021, October 22). Our finding on #SARSCoV2 and the brain´s microvasculature was published in @NatureNeuro today. We used cells, animal models, and #COVID19 [Tweet]. Twitter. https://twitter.com/NeuroVascWenz/status/1451284826645049349
