Fig 1.
Baseline inflammation in COVID-19 patients compared to healthy controls.
(A) The levels of PaO2/FiO2 and ARDS scoring in COVID-19 patients (B) circulating AAT and (C) CRP in COVID-19 patients compared to healthy controls, ***p<0.0005, ****p<0.0001 (two-tailed student’s t-test).
Table 1.
Baseline characteristics of the study population.
Fig 2.
Correlations among plasma profiles in the SARS-CoV2 patients.
(A) The correlation between plasma levels of CRP and AAT from COVID-19 patients. (B) Negative correlation between PaO2/FiO2 levels and plasma LDH levels. (C) Plasma LDH levels in survivors compared to non-survivors. (D and E) The correlation of LDH levels and plasma levels of CRP and AAT. (E) Severity of ARDS based on PaO2/FiO2 ratio values, **p<0.005 (two-tailed Mann-Whitney U test, Pearson correlation coefficients).
Fig 3.
Plasma levels of exosome associated neutrophil elastase (NE) in SARS-CoV2 patients.
(A) Higher plasma levels of exosome associated NE in SARS-CoV2 patients compared with healthy controls. (B) The association between exosome associated NE and plasma exosome associated levels of CD66 in SARS-CoV2 patients assessed by western blot analysis. (C) The correlation of the plasma levels of exosome associated NE in SARS-CoV2 patients with levels of free NE. (D) The correlation of the plasma levels of exosome associated NE in SARS-CoV2 patients with levels of CRP, (D) and AAT, ****p<0.0001 (two-tailed Mann-Whitney U test, Pearson correlation coefficients).
Fig 4.
Correlations among plasma exosome associated neutrophil elastase (NE) and endothelial injury in the SARS-CoV2-mediated ARDS patients.
(A) The correlation of plasma levels of exosome associated NE levels of LDH in SARS-CoV2 patients. (B) Soluble PECAM-1 plasma levels of SARS-CoV2 patients compared with healthy controls. (C) The correlation of plasma soluble PECAM-1 values with plasma exosome associated NE. (D) Negative correlation of PaO2/FiO2 ratio with soluble PECAM-1 values and (E) correlation between the plasma soluble PECAM-1 values and plasma levels of AAT in COVID-19 patients. (F) Plasma levels of Tissue Factor (TF) and (H) Thrombomodulin (TM) in SARS-CoV2 patients compared with healthy controls. (G) The correlation of plasma TF and (I) TM values with plasma exosome associated NE. ****p<0.0001(two-tailed Mann-Whitney U test, Pearson correlation coefficients, two-tailed student’s t-test).
Fig 5.
Exosomes from activated neutrophil-like cells carry surface neutrophil elastase (NE) in SARS-CoV2 patients.
(A) The size and concentration of the exosome from activated quiescent exosomes, assessed using nano tracker. (B) Similar size and (C) concentration of the quiescent and activated exosomes. (D) Exosomal markers of CD66 and CD81 assessed by western blot analysis. (D) The levels of NE in the exosomal fractions assessed by ELISA, *p<0.05 (two-tailed student’s t-test).
Fig 6.
Unchecked activity of exosome associated neutrophil elastase (NE) activates lung endothelial cells in vitro.
RNA expression levels of different pro-inflammatory cytokines in the MVECs analyzed 8 hours post treatment with purified NE, quiescent exosomes, and activated exosomes with or without purified AAT using qPCR, *p<0.05, **p<0.005, ***p<0.0005 (two-tailed student’s t-test).