There is nothing like living through a mystery thriller in real time (even if the mice are the heroes of this particular chapter). The entire planet wakes up each morning asking for more news about this little virus called “SARS- CoV2” (and the resulting COVID 19 disease). Some people want to know the case count or the death count. Some people want to know the latest news in vaccines or therapies. Some people just want to know whether their kid will be wearing a face mask in school this year or if vacation plans need to be delayed. No matter which camp you fall into, we all want answers on how to turn life normal again in the COVID twilight zone, and some mice have recently moved us a little closer.
In December of 2020, reports arrived about the spikes in mice’s brains. At first, this may seem like news about the mouse version of a rock band, but in reality the findings shed light on why both acute and long-hauler COVID patients suffer brain symptoms. Of course, during the acute phase COVID can definitely explain many neurological symptoms with its cytokine storms, blood clots, and disruptive inflammation, though the question of whether or not the virus itself attacks brain tissues is unsettled.
In this study, researchers found the S1 version of the SARS-CoV-2 in the brains of lab mice after they injected them with the spike protein. They published their finding in Nature Neuroscience and noted the the discovery is not unexpected since the gp120 protein which helps HIV cross the blood brain barrier also crosses into brain tissue. This brain inflammation could be from either the virus’s entry or from viral protein entering into the brain.
The research looked at both the entry of the spike protein through the nasal cavity and through the bloodstream. Both routes of entry into the body ended with spike protein in the brains, although the blood route showed higher levels. They looked at 11 different brains regions and found presence of the spike protein equally in all 11 regions. This accumulation of spike protein in the brain occurred despite the rapid filtering of the protein by the liver and the spleen.
Interestingly, the group also looked at whether wheatgerm agglutinin (WGA), a plant lectin, could affect the rate of spike protein uptake into the brain. They considered this question because the WGA itself crosses the blood brain barrier by a process called absorptive transcytosis. In their work, the addition of WGA increased movement of the labeled spike protein into the brain. This would strongly suggest that the spike protein also travels across the blood brain barrier by absorptive transcytosis. For a functional medicine doctor like myself, it makes me wonder if the high rate of gluten ingestions in our world might be increasing the uptake of the spike protein into the brains of COVID patients, though the authors don’t address this question.
The other route of entry looks to be the ACE2 receptor which is widely known to be a major factor in the pathology of COVID. Through a series of comparisons, they deduced that ACE2 affected the lungs and brain but not the spleen, liver, or kidney.
With all the inflammation resulting from COVID infection, the researchers also looked at whether this inflammation could increase the uptake of the spike protein into the brain or other tissues. They used lipopolysaccharide (LPS) from bacterium, known to trigger an inflammatory response, and monitored if the amount of spike protein increased in any tissue. The greatest increase was in the lungs, but the brain also showed an uptick.
So what does a functional MD do with this information? First, we keep reading and keep learning, checking each day for more insight into this new disease. Second, we apply what we already know about neuroinflammation and modulation of the immune system in order to both prevent illness and restore health. Finally, we care for each patient in front of us whether they have acute COVID or are long haulers by using personalized medicine that incorporates the best of natural and conventional therapies. We coordinate everything available to us to help those with long hauler COVID restore their healthier, more abundant lives.
Primary Article:
Rhea, E.M., Logsdon, A.F., Hansen, K.M. et al. The S1 protein of SARS-CoV-2 crosses the blood–brain barrier in mice. Nat Neurosci 24, 368–378 (2021). https://doi.org/10.1038/s41593-020-00771-8
1) Moriguchi, T. et al. A first case of meningitis/encephalitis associated with SARS-Coronavirus-2. Int. J. Infect. Dis. 94, 55–58 (2020).
2) Wang, J., Jiang, M., Chen, X. & Montaner, L. J. Cytokine storm and leukocyte changes in mild versus severe SARS-CoV-2 infection: review of 3,939 COVID-19 patients in China and emerging pathogenesis and therapy concepts. J. Leukoc. Biol. 108, 17–41 (2020).
Sanctuary Functional Medicine, under the direction of Dr Eric Potter, IFMCP MD, provides functional medicine services to Nashville, Middle Tennessee and beyond. We frequently treat patients from Kentucky, Alabama, Mississippi, Georgia, Ohio, Indiana, and more... offering the hope of healthier more abundant lives to those with chronic illness.
