Clinical implications of the plasma EphA2 receptor level in critically ill patients with septic shock

Inhibiting Eph/ephrin signaling reduces vascular leak and endothelial cell dysfunction in mice with sepsis

Sepsis is a life-threatening disease caused by a dysregulated host response to infection, resulting in 11 million deaths globally each year. Vascular endothelial cell dysfunction results in the loss of endothelial barrier integrity, which contributes to sepsis-induced multiple organ failure and mortality. Erythropoietin-producing hepatocellular carcinoma (Eph) receptors and their ephrin ligands play a key role in vascular endothelial barrier disruption but are currently not a therapeutic target in sepsis. Using a cecal ligation and puncture (CLP) mouse model of sepsis, we showed that prophylactic or therapeutic treatment of mice with EphA4-Fc, a decoy receptor and pan-ephrin inhibitor, resulted in improved survival and a reduction in vascular leak, lung injury, and endothelial cell dysfunction. EphA2-/- mice also exhibited reduced mortality and pathology after CLP compared with wild-type mice. Proteomics of plasma samples from mice with sepsis after CLP revealed dysregulation of a number of Eph/ephrins, including EphA2/ephrin A1. Administration of EphA4-Fc to cultured human endothelial cells pretreated with TNF-α or ephrin-A1 prevented loss of endothelial junction proteins, specifically VE-cadherin, with maintenance of endothelial barrier integrity. In children admitted to hospital with fever and suspected infection, we observed that changes in EphA2/ephrin A1 in serum samples correlated with endothelial and organ dysfunction. Targeting Eph/ephrin signaling may be a potential therapeutic strategy to reduce sepsis-induced endothelial dysfunction and mortality.

NADPH oxidase 4 signaling in a ventilator-induced lung injury mouse model

Background

For patients with acute respiratory distress syndrome, a ventilator is essential to supply oxygen to tissues, but it may also cause lung damage. In this study, we investigated the role of NOX4 using NOX4 knockout (KO) mice and NOX4 inhibitors in a ventilator-induced lung injury (VILI) model.

Methods

Wild-type (WT) male C57BL/6J mice and NOX4 knockout (KO) male mice were divided into five groups: (1) control group; (2) high tidal ventilation (HTV) group: WT mice + HTV ± DMSO; (3) NOX4 KO group; (4) NOX4 KO with HTV group; (5) NOX4 inhibitor group: WT mice + HTV + NOX4 inhibitor. In the VILI model, the supine position was maintained at 24 mL/kg volume, 0 cm H₂O PEEP, 100/min respiratory rate, and 0.21 inspired oxygen fraction. In the NOX4 inhibitor group, 50 μL anti-GKT 137831 inhibitor was injected intraperitoneally, 2 h after ventilator use. After 5 h of HTV, mice in the ventilator group were euthanized, and their lung tissues were obtained for further analysis. In addition, the relationship between EphA2 (which is related to lung injury) and NOX4 was investigated using EphA2 KO mice, and NOX4 and EphA2 levels in the bronchoalveolar lavage fluid (BALF) of 38 patients with pneumonia were examined.

Results

Cell counts from BALFs were significantly lower in the NOX4 KO with HTV group (p < 0.01) and EphA2 KO with HTV group (p < 0.001) compared to that in the HTV group. In the NOX4 inhibitor group, cell counts and protein concentrations from BALF were significantly lower than those in the HTV group (both, p < 0.001). In the NOX4 KO group and the NOX4 inhibitor group, EphA2 levels were significantly lower than those in the HTV group (p < 0.001). In patients with respiratory disease, NOX4 and EphA2 levels were significantly higher in patients with pneumonia and patients who received ventilator treatment in the intensive care unit.

Conclusion

In the VILI model with high tidal volume, NOX4 KO, EphA2 KO or monoclonal antibodies attenuated the VILI. NOX4 and EphA2 levels were significantly higher in patients with pneumonia and especially in mechanical ventilated in the ICU. Inhibition of Nox4 is a potential therapeutic target for the prevention and reduction of VILI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-01992-0.

Biological correlates before esophageal cancer screening and after diagnosis

Almost 50% of the world's esophageal cancer (EC) cases occur in China, and the impact of cancer screening has long been a controversial topic. The study was designed to evaluate the biological correlates of EC screening and subsequent diagnosis in China. Based on the national cohort of esophageal cancer program, a prospective multicenter study in high-risk regions was conducted from 2017 to 2019. 61 participants received twice esophageal endoscopy screening and pathological biopsy successively (with a mean follow-up of 14.03 months). Box-Cox-power transformation and two-way repeated measures ANOVA were used to evaluate hormone cortisol and immunoglobulin (IgA, IgG, IgM) levels in plasma, reflecting their stress, immune function, and biological correlates before screening and after knowing the diagnosis. The median of cortisol, IgA, IgG, and IgM in pre-screening was 15.46 ug/dL, 1.86 g/L, 12.14 g/L, and 0.91 g/L, corresponding value at post-diagnosis was 15.30 ug/dL, 2.00 g/L, 12.79 g/L, and 0.94 g/L, respectively. No significant differences in biological indicators were found between normal and esophagitis and low-grade intraepithelial neoplasia before screening and after diagnosis. After normality transformation, cortisol, IgA, IgG and IgM levels were (0.25 ± 0.04) U/mL, (0.72 ± 0.13) (g/L), (2.44 ± 0.22) (g/L) and (0.98 ± 0.25) (g/L) before screening, (0.25 ± 0.05) U/mL, (0.70 ± 0.13) (g/L), (2.48 ± 0.21) (g/L) and (1.00 ± 0.25) (g/L) after diagnosis, respectively. Repeated Measures ANOVA showed that the main effects were significant on IgA levels between pre-screening and post-diagnosis (P = 0.019). No interaction effects on biological levels between pre-post screening and esophageal pathology, anxiety states (all P > 0.05). Little biological correlates were found both before screening and after diagnosis. Cortisol and IgA dropped less significantly, while IgM and IgA were increased slightly after diagnosis. Further multi-round longitudinal studies are needed to validate these results.