ABSTRACT
Alzheimer's disease is a chronic neurodegenerative disorder and represents the main cause of dementia globally. Currently, the world is suffering from the coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a virus that uses angiotensin-converting enzyme 2 (ACE2) as a receptor to enter the host cells. In COVID-19, neurological manifestations have been reported to occur. The present study demonstrates that the protein expression level of ACE2 is upregulated in the brain of patients with Alzheimer's disease. The increased ACE2 expression is not age-dependent, suggesting the direct relationship between Alzheimer's disease and ACE2 expression. Oxidative stress has been implicated in the pathogenesis of Alzheimer's disease, and brains with the disease examined in this study also exhibited higher carbonylated proteins, as well as an increased thiol oxidation state of peroxiredoxin 6 (Prx6). A moderate positive correlation was found between the increased ACE2 protein expression and oxidative stress in brains with Alzheimer's disease. In summary, the present study reveals the relationships between Alzheimer's disease and ACE2, the receptor for SARS-CoV-2. These results suggest the importance of carefully monitoring patients with both Alzheimer's disease and COVID-19 in order to identify higher viral loads in the brain and long-term adverse neurological consequences.
Subject(s)
Alzheimer Disease/metabolism , Angiotensin-Converting Enzyme 2/metabolism , COVID-19/epidemiology , COVID-19/metabolism , Hippocampus/metabolism , Pandemics , Receptors, Virus/metabolism , SARS-CoV-2/metabolism , Up-Regulation , Alzheimer Disease/complications , Alzheimer Disease/pathology , Amyloid beta-Peptides/metabolism , Autopsy , COVID-19/complications , COVID-19/virology , Hippocampus/pathology , Humans , Oxidation-Reduction , Oxidative Stress , Peroxiredoxin VI/metabolism , Plaque, Amyloid/metabolism , Protein Carbonylation , Severity of Illness Index , Virus InternalizationABSTRACT
During the COVID-19 pandemic, research on "cytokine storms" has been reinvigorated in the field of infectious disease, but it also has particular relevance to cancer research. Interleukin-6 (IL-6) has emerged as a key component of the immune response to SARS-CoV-2, such that the repurposing of anti-IL-6 therapeutics for COVID-19 is now a major line of investigation, with several ongoing clinical trials. We lay a framework for understanding the role of IL-6 in the context of cancer research and COVID-19 and suggest how lessons learned from cancer research may impact SARS-CoV-2 research and vice versa.