Heterogeneity of immune cells and their communications unveiled by transcriptome profiling in acute inflammatory lung injury.

Background: Acute Respiratory Distress Syndrome (ARDS) or its earlier stage Acute lung injury (ALI), is a worldwide health concern that jeopardizes human well-being. Currently, the treatment strategies to mitigate the incidence and mortality of ARDS are severely restricted. This limitation can be attributed, at least in part, to the substantial variations in immunity observed in individuals with this syndrome. Methods: Bulk and single cell RNA sequencing from ALI mice and single cell RNA sequencing from ARDS patients were analyzed. We utilized the Seurat program package in R and cellmarker 2.0 to cluster and annotate the data. The differential, enrichment, protein interaction, and cell-cell communication analysis were conducted. Results: The mice with ALI caused by pulmonary and extrapulmonary factors demonstrated differential expression including Clec4e, Retnlg, S100a9, Coro1a, and Lars2. We have determined that inflammatory factors have a greater significance in extrapulmonary ALI, while multiple pathways collaborate in the development of pulmonary ALI. Clustering analysis revealed significant heterogeneity in the relative abundance of immune cells in different ALI models. The autocrine action of neutrophils plays a crucial role in pulmonary ALI. Additionally, there was a significant increase in signaling intensity between B cells and M1 macrophages, NKT cells and M1 macrophages in extrapulmonary ALI. The CXCL, CSF3 and MIF, TGFß signaling pathways play a vital role in pulmonary and extrapulmonary ALI, respectively. Moreover, the analysis of human single-cell revealed DCs signaling to monocytes and neutrophils in COVID-19-associated ARDS is stronger compared to sepsis-related ARDS. In sepsis-related ARDS, CD8+ T and Th cells exhibit more prominent signaling to B-cell nucleated DCs. Meanwhile, both MIF and CXCL signaling pathways are specific to sepsis-related ARDS. Conclusion: This study has identified specific gene signatures and signaling pathways in animal models and human samples that facilitate the interaction between immune cells, which could be targeted therapeutically in ARDS patients of various etiologies.

Pomelo (Citrus grandis (L.) Osbeck) sponge layers as a potential source of soluble dietary fiber: Evaluation of its physicochemical, structural and functional properties.

Pomelo sponge layer (PSL) had been considered as a potential source of soluble dietary fiber (SDF), while they were mostly disposed of as waste. To promote high-value utilization of pomelo wastes, this study extracted SDF from PSL of six varieties of pomelo, and their physicochemical, structural and functional properties were investigated. Results indicated that all PSL-SDFs showed good physicochemical and functional properties. Among them, PSL-SDF from grapefruit (GRSDF) showed better water holding capacity and swelling capacity, whereas Shatian pomelo PSL-SDF and Guanxi pomelo PSL-SDF had the highest thermal stability and oil holding capacity, respectively. Furthermore, compared with other PSL-SDFs, GRSDF displayed the lowest hydrolysis degree coupled with the best antioxidant and probiotic growth-promoting abilities. Finally, the correlation analysis showed that multiple beneficial effects of PSL-SDFs were markedly associated with their molecular weight and the concentrations of total phenolic, total flavonoids, rhamnose, galacturonic acid, glucose and arabinose. Collectively, these findings contributed to a better understanding of the physicochemical and functional properties of SDFs extracted from different PSLs, which provided a scientific basis for the development of PSL-SDFs into functional foods.

Neutrophil extracellular traps and their implications in airway inflammatory diseases.

Neutrophil extracellular traps (NETs) are essential for immune defense and have been increasingly recognized for their role in infection and inflammation. In the context of airway inflammatory diseases, there is growing evidence suggesting the involvement and significance of NETs. This review aims to provide an overview of the formation mechanisms and components of NETs and their impact on various airway inflammatory diseases, including acute lung injury/ARDS, asthma, chronic obstructive pulmonary disease (COPD) and cystic fibrosis. By understanding the role of NETs in airway inflammation, we can gain valuable insights into the underlying pathogenesis of these diseases and identify potential targets for future therapeutic strategies that either target NETs formation or modulate their harmful effects. Further research is warranted to elucidate the complex interactions between NETs and airway inflammation and to develop targeted therapies that can effectively mitigate their detrimental effects while preserving their beneficial functions in host defense.