Takafumi Kato1, Takanori Asakura1, Caitlin E Edwards2, Hong Dang1, Yu Mikami1, Kenichi Okuda1, Gang Chen1, Ling Sun1, Rodney C Gilmore1, Padraig Hawkins1, Gabriela De la Cruz3, Michelle R Cooley2, Alexis B Bailey2, Stephen M Hewitt4, Daniel S Chertow5, Alain C Borczuk6, Steven Salvatore7, Fernando J Martinez8, Leigh B Thorne9, Frederic B Askin9, Camille Ehre1, Scott H Randell1, Wanda K O'Neal10, Ralph S Baric2, Richard C Boucher11. 1. University of North Carolina at Chapel Hill School of Medicine, 6797, Marsico Lung Institute, Chapel Hill, North Carolina, United States. 2. University of North Carolina at Chapel Hill School of Medicine, 6797, Department of Epidemiology, Chapel Hill, North Carolina, United States. 3. University of North Carolina at Chapel Hill School of Medicine, 6797, Pathology Services Core, Chapel Hill, North Carolina, United States. 4. National Cancer Institute, 3421, Center for Cancer Research, Bethesda, Maryland, United States. 5. NIH Clinical Center, 24481, Critical Care Medicine Department, Bethesda, Maryland, United States. 6. Weill Cornell Medicine, 12295, Anatomic Pathology, New York, New York, United States. 7. Weill Cornell Medicine, 12295, Pathology and Laboratory Medicine , New York, New York, United States. 8. Weill Cornell Medicine, 12295, Pulmonary Critical Care Medicine, New York, New York, United States. 9. University of North Carolina at Chapel Hill School of Medicine, 6797, Department of Pathology and Laboratory Medicine, Chapel Hill, North Carolina, United States. 10. University of North Carolina at Chapel Hill, 2331, Marsico Lung Institute/Cystic Fibrosis Research Center, Chapel Hill, North Carolina, United States. 11. University of North Carolina at Chapel Hill School of Medicine, 6797, Marsico Lung Institute, Chapel Hill, North Carolina, United States; richard_boucher@med.unc.edu.
Abstract
RATIONALE: The incidence and sites of mucus accumulation, and molecular regulation of mucin gene expression, in COVID-19 lung disease have not been reported. OBJECTIVES: Characterize incidence of mucus accumulation and the mechanisms mediating mucin hypersecretion in COVID-19 lung disease. METHODS: Airway mucus and mucins were evaluated in COVID-19 autopsy lungs by AB-PAS and immunohistochemical staining, RNA in situ hybridization, and spatial transcriptional profiling. SARS-CoV-2-infected human bronchial epithelial (HBE) cultures were utilized to investigate mechanisms of SARS-CoV-2-induced mucin expression and synthesis and test candidate countermeasures. MEASUREMENTS AND MAIN RESULTS: MUC5B and variably MUC5AC RNA levels were increased throughout all airway regions of COVID-19 autopsy lungs, notably in the sub-acute/chronic disease phase following SARS-CoV-2 clearance. In the distal lung, MUC5B-dominated mucus plugging was observed in 90% of COVID-19 subjects in both morphologically identified bronchioles and microcysts, and MUC5B accumulated in damaged alveolar spaces. SARS-CoV-2-infected HBE cultures exhibited peak titers 3 days post inoculation, whereas induction of MUC5B/MUC5AC peaked 7-14 days post inoculation. SARS-CoV-2 infection of HBE cultures induced expression of EGFR ligands and inflammatory cytokines (e.g., IL-1α/β) associated with mucin gene regulation. Inhibiting EGFR/IL-1R pathways, or dexamethasone administration, reduced SARS-CoV-2-induced mucin expression. CONCLUSIONS: SARS-CoV-2 infection is associated with a high prevalence of distal airspace mucus accumulation and increased MUC5B expression in COVID-19 autopsy lungs. HBE culture studies identified roles for EGFR and IL-1R signaling in mucin gene regulation post SARS-CoV-2 infection. These data suggest that time-sensitive mucolytic agents, specific pathway inhibitors, or corticosteroid administration may be therapeutic for COVID-19 lung disease. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/).
RATIONALE: The incidence and sites of mucus accumulation, and molecular regulation of mucin gene expression, in COVID-19 lung disease have not been reported. OBJECTIVES: Characterize incidence of mucus accumulation and the mechanisms mediating mucin hypersecretion in COVID-19 lung disease. METHODS: Airway mucus and mucins were evaluated in COVID-19 autopsy lungs by AB-PAS and immunohistochemical staining, RNA in situ hybridization, and spatial transcriptional profiling. SARS-CoV-2-infected human bronchial epithelial (HBE) cultures were utilized to investigate mechanisms of SARS-CoV-2-induced mucin expression and synthesis and test candidate countermeasures. MEASUREMENTS AND MAIN RESULTS: MUC5B and variably MUC5AC RNA levels were increased throughout all airway regions of COVID-19 autopsy lungs, notably in the sub-acute/chronic disease phase following SARS-CoV-2 clearance. In the distal lung, MUC5B-dominated mucus plugging was observed in 90% of COVID-19 subjects in both morphologically identified bronchioles and microcysts, and MUC5B accumulated in damaged alveolar spaces. SARS-CoV-2-infected HBE cultures exhibited peak titers 3 days post inoculation, whereas induction of MUC5B/MUC5AC peaked 7-14 days post inoculation. SARS-CoV-2 infection of HBE cultures induced expression of EGFR ligands and inflammatory cytokines (e.g., IL-1α/β) associated with mucin gene regulation. Inhibiting EGFR/IL-1R pathways, or dexamethasone administration, reduced SARS-CoV-2-induced mucin expression. CONCLUSIONS: SARS-CoV-2 infection is associated with a high prevalence of distal airspace mucus accumulation and increased MUC5B expression in COVID-19 autopsy lungs. HBE culture studies identified roles for EGFR and IL-1R signaling in mucin gene regulation post SARS-CoV-2 infection. These data suggest that time-sensitive mucolytic agents, specific pathway inhibitors, or corticosteroid administration may be therapeutic for COVID-19 lung disease. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Authors: Kangyun Wu; Yong Zhang; Stephen R Austin; Huqing Yin Declue; Derek E Byers; Erika C Crouch; Michael J Holtzman Journal: medRxiv Date: 2022-09-19