Background Coronavirus disease 2019 (COVID‐19) emerged in Wuhan city and rapidly spread globally outside China. We aimed to investigate the role of peripheral blood eosinophil (EOS) as a marker in the course of the virus infection to improve the efficiency of diagnosis and evaluation of COVID‐19 patients. Methods 227 pneumonia patients who visited the fever clinics in Shanghai General Hospital and 97 hospitalized COVID‐19 patients admitted to Shanghai Public Health Clinical Center were involved in a retrospective research study. Clinical, laboratory, and radiologic data were collected. The trend of EOS level in COVID‐19 patients and comparison among patients with different severity were summarized. Results The majority of COVID‐19 patients (71.7%) had a decrease in circulating EOS counts, which was significantly more frequent than other types of pneumonia patients. EOS counts had good value for COVID‐19 prediction, even higher when combined with neutrophil‐to‐lymphocyte ratio. Patients with low EOS counts at admission were more likely to have fever, fatigue, and shortness of breath, with more lesions in chest CT and radiographic aggravation, and longer length of hospital stay and course of disease than those with normal EOS counts. Circulating EOS level gradually increased over the time, and was synchronous with the improvement in chest CT (12 days vs 13 days, P = .07), later than that of body temperature (12 days vs 10 days, P = .014), but earlier than that of the negative conversion of nucleic acid assays (12 days vs 17 days, P = .001). Conclusion Peripheral blood EOS counts may be an effective and efficient indicator in diagnosis, Evaluation, and prognosis monitoring of COVID‐19 patients.

This is an Open Access article licensed under the terms of the Creative Commons AttributionNonCommercial 3.0 Unported license (CC BY-NC) (www.karger.com/OA-license), applicable to the online version of the article only. Distribution permitted for non-commercial purposes only. Abstract Background/Aims: Angiotensin converting enzyme 2 (ACE2) treatment suppresses the severity of acute lung injury (ALI). The effects of ACE2 in ALI have been shown to not only result from its antagonizing hydrolyzing angiotensin II (AngII), which is responsible for reduction in the vascular tension and pulmonary accumulation of inflammatory cells, but also result from a role of ACE2 in suppressing the ALI-induced apoptosis of pulmonary endothelial cells (PECs). Nevertheless, the underlying mechanisms of the role of ACE2 on PEC apoptosis are not completely understood. Methods: Here, we used a bleomycin-induced mouse model for ALI that has been published in our previous studies. We analyzed the mRNA and protein levels of an anti-apoptotic protein Bcl-2 in the ALI-mice that have been treated w/o ACE2. We analyzed miR-4262 levels in the mouse lung in these mice. Bcl-2-targeting miRNAs were predicted using bioinformatics algorithms and a luciferase reporter assay was applied to examine the effects of miR-4262 on the Bcl-2 protein translation upon their binding to 3'-UTR of Bcl-2 mRNA. Adeno-associated viruses carrying either miR-4262 mimics or antisense were injected into ALI-mice without ACE2, and their effects on the apoptosis in mouse lung cells were analyzed by Western blot. Results: ACE2 inhibited the ALI-induced apoptosis of pulmonary cells in vivo partially through upregulation of Bcl-2 protein, but not Bcl-2 mRNA. ACE2 appeared to significantly suppress the upregulation of miR-4262 in mouse lung after ALI. MiR-4262 was found to target 3'-UTR of Bcl-2 mRNA to inhibit its protein translation in PECs. In vivo administration of antisense of miR-4262 decreased apoptosis of pulmonary cells and severity of the ALI in mice. Conclusion: ACE2-induced suppression of miR-4262 partially contribute to the inhibition of the PEC apoptosis after ALI through Bcl-2. MiR-4262 may be a novel promising treatment target for ALI and ARDS.

Butts work for the study sponsor, Merck & Co. H. Nolte and K. Lund are employed by ALK A/S. T. Mant is employed by Quintiles IMS. G. Clarke declares no relevant conflicts of interest.

The application of these new cut-points would reclassify about one-third of the patients with COPD and, thus, would impact on individual disease management. Further validation in prospective studies of these new values are needed.

The purpose of this study is to observe the potential of lung ultrasound in evaluating the severity of coronavirus disease 2019 (COVID-19) pneumonia. Lung ultrasound was performed in ten zones of the patients' chest walls. The features of the ultrasound images were observed, and a lung ultrasound score (LUS) was recorded. The ultrasound features and scores were compared between the refractory group (PaO 2 /FiO 2 ≤ 100 mm Hg or on extracorporeal membrane oxygenation) and the non-refractory group. The prediction value of the LUS was studied by receiver operating characteristic (ROC) curve analysis. In total, 7 patients were enrolled in the refractory group and 28 in the non-refractory group. B-line patterns and shred signs were the most common signs in all patients. Patients in the refractory group had significantly more ground-glass signs (median 6 [interquartile range {IQR}, 2.5–6.5] vs. median 0 [IQR, 0–3]), consolidation signs (median 1 [IQR, 1–1.5] vs. median 0 [IQR, 0–3]) and pleural effusions (median 5 [IQR, 1.5–6] vs. median 0 [IQR, 0–0.25]). The LUS was significantly higher in the refractory group (33.00 [IQR 27.50–34.00] vs. 25.50 [IQR 22.75–30.00]). The ROC of the LUS showed a cutoff score of 32 with a specificity of 0.893 and a sensitivity of 0.571 in diagnosing refractory respiratory failure among patients. In COVID-19 patients, lung ultrasound is a promising diagnostic tool in diagnosing patients with refractory pneumonia.

Background Recent evidence has shown that C-X-C chemokine receptor type 4 (CXCR4) plays a crucial role in acute lung injury (ALI). Macrophages are key factors in the pathogenesis of ALI. The aim of this study was to investigate the role of CXCR4 in macrophages after lipopolysaccharide (LPS) stimulation and confirm that CXCR4 knockdown can inhibit inflammatory cytokines by suppressing mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) signaling pathway activation. Results In this study, we found that CXCR4 expression in lung tissue of ALI was significantly increased using immunofluorescence. We also found that the expression of CXCR4 in macrophages sorted from bronchoalveolar lavage fluid (BALF) of ALI was obviously upregulated through RT-qPCR. After CXCR4 knockdown using siRNA, we found that the expression of interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) was obviously down regulated in macrophages. Additionally, the phosphorylation of p38, Erk, and p65 was significantly decreased after CXCR4 knockdown through western blotting. Conclusions Taken together, the present study suggests that CXCR4 knockdown may inhibit inflammatory cytokine expression in macrophages by suppressing MAPK and NF-κB signaling pathway activation. Therefore, CXCR4 knockdown may have potential clinical value in treating ALI.

BackgroundCancer cells release exosomes and can be taken up by mast cells (MCs), but the potential functional effects of MCs on tumor metastasis remain unknown.MethodExosomes were isolated from the lung adenocarcinoma cell line A549, and the uptake of PKH26-labeled exosomes by bone marrow MCs was examined via flow cytometry and fluorescence microscopy. Cytokines and tryptase in MC supernatant were analyzed using an ELISA kit, and the presence of tryptase was evaluated by Western blotting. Cell proliferation and migration were determined through CCK-8 and transwell assays. Proteins in the tryptase-JAK-STAT signaling pathway were detected by Western blotting.ResultsIn this study, we show that exosomes from A549 cells can be taken up by MCs. Moreover, A549 exosomes contain stem cell factor (SCF) to MCs and subsequently induce the activation of MCs through SCF-KIT signal transduction, which leads to MC degranulation and the release of tryptase. Tryptase accelerates the proliferation and migration of human umbilical vein endothelial cells (HUVECs) through the JAK-STAT signaling pathway.ConclusionsOur results reveal a mechanism for metastasis in which exosomes can transfer SCF to and activate MCs, which can affect the release of tryptase and the angiogenesis of HUVECs.

Mast cells (MCs) are known to participate in a variety of patho-physiological processes depending largely on the intragranular mediators and the production of cytokines and chemokines during degranulation. Recently, extracellular vesicles (EVs) have been implicated important functions for MCs, but the components of MC-derived EVs have not yet been well-characterized. In this study, we aimed to identify signatures of proteins, long non-coding RNAs (lncRNAs), and microRNAs (miRNAs) in EVs derived from resting (Rest-EV) and degranulated (Sti-EV) MCs by differential ultracentrifugation. Using tandem mass tag (TMT)-based quantitative proteomics technology and RNA sequencing, we identified a total of 1988 proteins, 397 lncRNAs, and 272 miRNAs in Rest-EV and Sti-EV. The proteins include common EVs markers (cytoskeletal proteins), MCs markers (FcεRI and tryptase), and some preformed MCs mediators (lysosomal enzymes) as well. The global expression profiles of lncRNAs and miRNAs identified, for the first time, from Rest-EV and Sti-EV, strongly suggest a potential regulatory function of MC-derived EVs. We have also performed Western blotting and qRT-PCR analysis to further verify some of the proteins, lncRNAs, and miRNAs identified from Rest-EV and Sti-EV. Our findings will help to elucidate the functions of MC-derived EVs, and provide a reference dataset for future translational studies involving MC-derived EVs.