TY - JOUR
T1 - Direct endothelial ENaC activation mitigates vasculopathy induced by SARS-CoV2 spike protein
AU - Romero, Maritza J.
AU - Yue, Qian
AU - Singla, Bhupesh
AU - Hamacher, Jürg
AU - Sridhar, Supriya
AU - Moseley, Auriel S.
AU - Song, Chang
AU - Mraheil, Mobarak A.
AU - Fischer, Bernhard
AU - Zeitlinger, Markus
AU - Chakraborty, Trinad
AU - Fulton, David
AU - Gan, Lin
AU - Annex, Brian H.
AU - Csanyi, Gabor
AU - Eaton, Douglas C.
AU - Lucas, Rudolf
N1 - Funding Information:
BS was supported by NHLBI grant K99HL146954. MAM was supported by the Transregional Collaborative Research Centre SFB TR 84 from the DFG (Innate Immunity of the Lung: Mechanisms of Pathogen Attack and Host Defense in Pneumonia). GC received funding from NIH/NHLBI grants R01 HL164792 and R01 HL139562. BHA was funded by NIH grants R01GM129074, R01HL148590 and R01HL141325. DF received funding from the American Heart Association (AHA) award 19TPA34910080 and from the NIH/NHLBI grants R01 HL156646 and R01 HL125926. DCE was funded by NIH grant DK110409. RL was funded by an intramural pilot grant and a Bridge Funding grant from the Office of the senior Vice President for Research at Augusta University, by a TPA award from the American Heart Association 23TPA1072536 (DOI): https://doi.org/10.58275/AHA.23TPA1072536.pc.gr.172267 and by NIH/NHLBI grant R01 HL138410. Acknowledgments
Publisher Copyright:
Copyright © 2023 Romero, Yue, Singla, Hamacher, Sridhar, Moseley, Song, Mraheil, Fischer, Zeitlinger, Chakraborty, Fulton, Gan, Annex, Csanyi, Eaton and Lucas.
PY - 2023
Y1 - 2023
N2 - Introduction: Although both COVID-19 and non-COVID-19 ARDS can be accompanied by significantly increased levels of circulating cytokines, the former significantly differs from the latter by its higher vasculopathy, characterized by increased oxidative stress and coagulopathy in lung capillaries. This points towards the existence of SARS-CoV2-specific factors and mechanisms that can sensitize the endothelium towards becoming dysfunctional. Although the virus is rarely detected within endothelial cells or in the circulation, the S1 subunit of its spike protein, which contains the receptor binding domain (RBD) for human ACE2 (hACE2), can be detected in plasma from COVID-19 patients and its levels correlate with disease severity. It remains obscure how the SARS-CoV2 RBD exerts its deleterious actions in lung endothelium and whether there are mechanisms to mitigate this. Methods: In this study, we use a combination of in vitro studies in RBD-treated human lung microvascular endothelial cells (HL-MVEC), including electrophysiology, barrier function, oxidative stress and human ACE2 (hACE2) surface protein expression measurements with in vivo studies in transgenic mice globally expressing human ACE2 and injected with RBD. Results: We show that SARS-CoV2 RBD impairs endothelial ENaC activity, reduces surface hACE2 expression and increases reactive oxygen species (ROS) and tissue factor (TF) generation in monolayers of HL-MVEC, as such promoting barrier dysfunction and coagulopathy. The TNF-derived TIP peptide (a.k.a. solnatide, AP301) -which directly activates ENaC upon binding to its a subunit- can override RBD-induced impairment of ENaC function and hACE2 expression, mitigates ROS and TF generation and restores barrier function in HL-MVEC monolayers. In correlation with the increased mortality observed in COVID-19 patients co-infected with S. pneumoniae, compared to subjects solely infected with SARS-CoV2, we observe that prior intraperitoneal RBD treatment in transgenic mice globally expressing hACE2 significantly increases fibrin deposition and capillary leak upon intratracheal instillation of S. pneumoniae and that this is mitigated by TIP peptide treatment.
AB - Introduction: Although both COVID-19 and non-COVID-19 ARDS can be accompanied by significantly increased levels of circulating cytokines, the former significantly differs from the latter by its higher vasculopathy, characterized by increased oxidative stress and coagulopathy in lung capillaries. This points towards the existence of SARS-CoV2-specific factors and mechanisms that can sensitize the endothelium towards becoming dysfunctional. Although the virus is rarely detected within endothelial cells or in the circulation, the S1 subunit of its spike protein, which contains the receptor binding domain (RBD) for human ACE2 (hACE2), can be detected in plasma from COVID-19 patients and its levels correlate with disease severity. It remains obscure how the SARS-CoV2 RBD exerts its deleterious actions in lung endothelium and whether there are mechanisms to mitigate this. Methods: In this study, we use a combination of in vitro studies in RBD-treated human lung microvascular endothelial cells (HL-MVEC), including electrophysiology, barrier function, oxidative stress and human ACE2 (hACE2) surface protein expression measurements with in vivo studies in transgenic mice globally expressing human ACE2 and injected with RBD. Results: We show that SARS-CoV2 RBD impairs endothelial ENaC activity, reduces surface hACE2 expression and increases reactive oxygen species (ROS) and tissue factor (TF) generation in monolayers of HL-MVEC, as such promoting barrier dysfunction and coagulopathy. The TNF-derived TIP peptide (a.k.a. solnatide, AP301) -which directly activates ENaC upon binding to its a subunit- can override RBD-induced impairment of ENaC function and hACE2 expression, mitigates ROS and TF generation and restores barrier function in HL-MVEC monolayers. In correlation with the increased mortality observed in COVID-19 patients co-infected with S. pneumoniae, compared to subjects solely infected with SARS-CoV2, we observe that prior intraperitoneal RBD treatment in transgenic mice globally expressing hACE2 significantly increases fibrin deposition and capillary leak upon intratracheal instillation of S. pneumoniae and that this is mitigated by TIP peptide treatment.
KW - Epithelial sodium channel (ENaC)
KW - NADPH oxidase 2 (NOX2)
KW - SARS-CoV2 spike protein
KW - endothelial dysfunction
KW - human ACE-2
KW - receptor binding domain (RBD)
KW - tissue factor
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U2 - 10.3389/fimmu.2023.1241448
DO - 10.3389/fimmu.2023.1241448
M3 - Article
C2 - 37638055
AN - SCOPUS:85168657874
SN - 1664-3224
VL - 14
JO - Frontiers in immunology
JF - Frontiers in immunology
M1 - 1241448
ER -