Alzheimer's-like signaling in brains of COVID-19 patients.

INTRODUCTION: The mechanisms that lead to cognitive impairment associated with COVID-19 are not well understood. METHODS: Brain lysates from control and COVID-19 patients were analyzed for oxidative stress and inflammatory signaling pathway markers, and measurements of Alzheimer's disease (AD)-linked signaling biochemistry. Post-translational modifications of the ryanodine receptor/calcium (Ca2+ ) release channels (RyR) on the endoplasmic reticuli (ER), known to be linked to AD, were also measured by co-immunoprecipitation/immunoblotting of the brain lysates. RESULTS: We provide evidence linking SARS-CoV-2 infection to activation of TGF-ß signaling and oxidative overload. The neuropathological pathways causing tau hyperphosphorylation typically associated with AD were also shown to be activated in COVID-19 patients. RyR2 in COVID-19 brains demonstrated a "leaky" phenotype, which can promote cognitive and behavioral defects. DISCUSSION: COVID-19 neuropathology includes AD-like features and leaky RyR2 channels could be a therapeutic target for amelioration of some cognitive defects associated with SARS-CoV-2 infection and long COVID.

Dantrolene repurposed to treat sepsis or septic shock and COVID-19 patients.

OBJECTIVE: Disruption of intracellular Ca2+ homeostasis via excessive and pathological Ca2+ release from the endoplasmic reticulum (ER) and/or sarcoplasmic reticulum (SR) through ryanodine receptor (RyRs) Ca2+ channels play a critical role in the pathology of systemic inflammatory response syndrome (SIRS) and associated multiple organ dysfunction syndrome (MODS) in sepsis or septic shock. Dantrolene, a potent inhibitor of RyRs, is expected to ameliorate SIRS and MODS and decrease mortality in sepsis or septic shock patients. This review summarized the potential mechanisms of therapeutic effects of dantrolene in sepsis or septic shock at molecular, cell, and organ levels and provided suggestions and strategies for future clinical studies.