Transcriptome analysis reveals the impact of NETs activation on airway epithelial cell EMT and inflammation in bronchiolitis obliterans.

Bronchiolitis obliterans (BO) is a chronic airway disease that was often indicated by the pathological presentation of narrowed and irreversible airways. However, the molecular mechanisms of BO pathogenesis remain unknown. Although neutrophil extracellular traps (NETs) can contribute to inflammatory disorders, their involvement in BO is unclear. This study aims to identify potential signaling pathways in BO by exploring the correlations between NETs and BO. GSE52761 and GSE137169 datasets were downloaded from gene expression omnibus (GEO) database. A series of bioinformatics analyses such as differential expression analysis, gene ontology (GO), Kyoto encyclopedia of genes and genomes (KEGG), and gene set enrichment analysis (GSEA) were performed on GSE52761 and GSE137169 datasets to identify BO potential signaling pathways. Two different types of BO mouse models were constructed to verify NETs involvements in BO. Additional experiments and bioinformatics analysis using human small airway epithelial cells (SAECs) were also performed to further elucidate differential genes enrichment with their respective signaling pathways in BO. Our study identified 115 differentially expressed genes (DEGs) that were found up-regulated in BO. Pathway enrichment analysis revealed that these genes were primarily involved in inflammatory signaling processes. Besides, we found that neutrophil extracellular traps (NETs) were formed and activated during BO. Our western blot analysis on lung tissue from BO mice further confirmed NETs activation in BO, where neutrophil elastase (NE) and myeloperoxidase (MPO) expression were found significantly elevated. Transcriptomic and bioinformatics analysis of NETs treated-SAECs also revealed that NETs-DEGs were primarily associated through inflammatory and epithelial-to-mesenchymal transition (EMT) -related pathways. Our study provides novel clues towards the understanding of BO pathogenesis, in which NETs contribute to BO pathogenesis through the activation of inflammatory and EMT associated pathways. The completion of our study will provide the basis for potential novel therapeutic targets in BO treatment.

Coinfection with influenza virus and non-typeable Haemophilus influenzae aggregates inflammatory lung injury and alters gut microbiota in COPD mice.

Background: Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is associated with high mortality rates. Viral and bacterial coinfection is the primary cause of AECOPD. How coinfection with these microbes influences host inflammatory response and the gut microbiota composition is not entirely understood. Methods: We developed a mouse model of AECOPD by cigarette smoke exposure and sequential infection with influenza H1N1 virus and non-typeable Haemophilus influenzae (NTHi). Viral and bacterial titer was determined using MDCK cells and chocolate agar plates, respectively. The levels of cytokines, adhesion molecules, and inflammatory cells in the lungs were measured using Bio-Plex and flow cytometry assays. Gut microbiota was analyzed using 16S rRNA gene sequencing. Correlations between cytokines and gut microbiota were determined using Spearman's rank correlation coefficient test. Results: Coinfection with H1N1 and NTHi resulted in more severe lung injury, higher mortality, declined lung function in COPD mice. H1N1 enhanced NTHi growth in the lungs, but NTHi had no effect on H1N1. In addition, coinfection increased the levels of cytokines and adhesion molecules, as well as immune cells including total and M1 macrophages, neutrophils, monocytes, NK cells, and CD4 + T cells. In contrast, alveolar macrophages were depleted. Furthermore, coinfection caused a decline in the diversity of gut bacteria. Muribaculaceae, Lactobacillus, Akkermansia, Lachnospiraceae, and Rikenella were further found to be negatively correlated with cytokine levels, whereas Bacteroides was positively correlated. Conclusion: Coinfection with H1N1 and NTHi causes a deterioration in COPD mice due to increased lung inflammation, which is correlated with dysbiosis of the gut microbiota.

B-lymphocyte deficiency and recurrent respiratory infections in a 6-month-old female infant with mosaic monosomy 7.

Monosomy 7 is generally considered as an acquired cytogenetic abnormality within hematopoietic cells, and indicates an especially high risk of progression to bone marrow failure, myelodysplastic syndrome (MDS) or juvenile myelomonocytic leukemia (JMML). We report a case of a 6-month-old female infant with mosaic monosomy 7 who presented with clinical and laboratory evidences of immunodeficiency. The patient had suffered from recurrent respiratory infections since she was born. Peripheral blood lymphocyte subsets revealed an extremely low level of CD19+ B lymphocytes (0.3∼0.8%, normal range: 6.4∼22.6%) and a decreased CD4/CD8 ratio (0.67∼1.12, normal range: 1.4∼2.0). Decreased serum levels of IgG (1.53 g/L, normal range: 4.09∼7.03 g/L), IgA (0.10 g/L, normal range: 0.21∼0.47 g/L) and IgM (0.26 g/L, normal range: 0.33∼0.73 g/L) were detected, while complements were normal. Excepting transient neutropenia, routine blood tests were within normal limits. Clinical exome sequencing identified a de novo mosaic monosomy 7, while no pathogenic mutation associated with immunodeficiency was detected. However, peripheral blood cytogenetic analysis was failure to detect monosomy 7 due to the very few cell mitosis. Subsequent fluorescence in situ hybridization (FISH) identified a mosaic monosomy 7 in 58 cells within a total number of 100 cells, which was consistent with clinical exome sequencing. Therefore, the patient was diagnosed with primary immunodeficiency disease (PID) due to mosaic monosomy 7. Intravenous treatment with multiple antibiotic agents and infusion of gamma globulin could control the patient's respiratory infections effectively. A better understanding of PIDs will enable effective treatments and prevention of infections in these patients.