The SARS-CoV-2 main protease induces capillary cell death by cleaving NEMO in brain endothelial cells

Background: Several lines of evidence suggest that neurological symptoms in patients suffering from Coronavirus disease 2019 (COVID-19) occur partially due to damage to small vessels in the brain. However, the potential mechanisms underlying this pathology are unclear. Aim: Here, we describe a novel pathway by which SARSCoV- 2 affects the brain vasculature and thereby potentially induces neurocognitive impairment in patients. Method: We examined brain tissue of deceased COVID- 19 patients and different animal models of this disease for microvascular pathology. Using several techniques like mass spectrometry, high resolution microscopy, transgenic animals, and AAV-mediated gene transfer, we investigated the effect of the SARS-CoV-2 main protease (Mpro) on brain endothelial cells. Results/Conclusions: In brains of SARS-CoV-2-infected individuals and animal models, we found an increased number of empty basement membrane tubes, so-called string vessels representing remnants of lost capillaries. We obtained evidence that brain endothelial cells are infected, and that Mpro cleaves NEMO, the essential modulator of nuclear factor-jB. By ablating NEMO, Mpro induces the death of human brain endothelial cells and the occurrence of string vessels in mice. Deletion of RIPK3, a mediator of regulated cell death, blocks the vessel rarefaction and disruption of the blood-brain barrier due to NEMO ablation. Importantly, a pharmacological inhibitor of RIPK signaling prevented the Mpro-induced microvascular pathology. These data suggest a novel mechanism by which SARS-CoV-2 affects the brain vasculature and a potential therapeutic option to interfere with the neurological consequences of COVID-19.

[COVID-19 and the central and peripheral nervous system]. / COVID-19: Auswirkungen auf das zentrale und periphere Nervensystem.

The health effects of coronavirus disease 2019 (COVID-19) caused by the infection of SARS-CoV­2 (severe acute respiratory syndrome coronavirus 2) are becoming increasingly clear as the pandemic spreads. In addition to the lungs, other organs are also affected, which can significantly influence morbidity and mortality. In particular, neurological symptoms involving the central nervous system can lead to acute or long-term consequences. The mechanisms of this neuropathogenesis of SARS-CoV­2 infection and its relation to acute and chronic neurological symptoms are the subject of current studies investigating a potential direct and indirect viral infection of the nervous system. The following review summarizes the current status of neuropathological manifestations, molecular pathogenesis, possible infection pathways in the nervous system, and systemic effects. In addition, an overview of the Germany-wide CNS-COVID19 registry and collaborations is presented, which should contribute to a better understanding of the neurological symptoms of COVID-19.