Dermatophagoides farinae microRNAs released to external environments via exosomes regulate inflammation-related gene expression in human bronchial epithelial cells.

Background: Dermatophagoides farinae (DFA) is an important species of house dust mites (HDMs) that causes allergic diseases. Previous studies have focused on allergens with protein components to explain the allergic effect of HDMs; however, there is little knowledge on the role of microRNAs (miRNAs) in the allergic effect of HDMs. This study aimed to unravel the new mechanism of dust mite sensitization from the perspective of cross-species transport of extracellular vesicles-encapsulated miRNAs from HDMs. Methods: Small RNA (sRNA) sequencing was performed to detect miRNAs expression profiles from DFA, DFA-derived exosomes and DFA culture supernatants. A quantitative fluorescent real-time PCR (qPCR) assay was used to detect miRNAs expression in dust specimens. BEAS-2B cells endocytosed exosomes were modeled in vitro to detect miRNAs from DFA and the expression of related inflammatory factors. Representative dfa-miR-276-3p and dfa-novel-miR2 were transfected into BEAS-2B cells, and then differentially expressed genes (DEGs) were analyzed by RNA sequencing. Protein-protein interaction (PPI) network analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and Gene Ontology (GO) terms enrichment analyses were performed on the first 300 nodes of DEGs. Results: sRNA sequencing identified 42 conserved miRNAs and 66 novel miRNAs in DFA, DFA-derived exosomes, and DFA culture supernatants. A homology analysis was performed on the top 18 conserved miRNAs with high expression levels. The presence of dust mites and miRNAs from HDMs in living environment were also validated. Following uptake of DFA-derived exosomes by BEAS-2B cells, exosomes transported miRNAs from DFA to target cells and produced pro-inflammatory effects in corresponding cells. RNA sequencing identified DEGs in dfa-miR-276-3p and dfa-novel-miR2 transfected BEAS-2B cells. GO and KEGG enrichment analyses revealed the role of exosomes with cross-species transporting of DFA miRNAs in inflammatory signaling pathways, such as JAK-STAT signaling pathway, PI3K/AKT signaling pathway and IL-6-mediated signaling pathway. Conclusion: Our findings demonstrate the miRNAs expression profiles in DFA for the first time. The DFA miRNAs are delivered into living environments via exosomes, and engulfed by human bronchial epithelial cells, and cross-species regulation may contribute to inflammation-related processes.

Exosomes Derived from Dermatophagoides farinae Induce Allergic Airway Inflammation.

House dust mites (HDMs) are a major source of indoor allergens that cause airway allergic disease. Dermatophagoides farinae, a predominant species of HDMs in China, has demonstrated pathogenic role in allergic disorders. Exosomes derived from human bronchoalveolar lavage fluid have been strongly associated with allergic respiratory diseases progression. However, the pathogenic role of D. farinae-derived exosomes in allergic airway inflammation has remained unclear until now. Here, D. farinae was stirred overnight in phosphate-buffered saline, and the supernatant was used to extract exosomes by ultracentrifugation. Then, shotgun liquid chromatography-tandem mass spectrometry and small RNA sequencing were performed to identify proteins and microRNAs contained in D. farinae exosomes. Immunoblotting, Western blotting, and enzyme-linked immunosorbent assay demonstrated the specific immunoreactivity of D. farinae-specific serum IgE antibody against D. farinae exosomes, and D. farinae exosomes were found to induce allergic airway inflammation in a mouse model. In addition, D. farinae exosomes invaded 16-HBE bronchial epithelial cells and NR8383 alveolar macrophages to release the inflammation-related cytokines interleukin-33 (IL-33), thymic stromal lymphopoietin, tumor necrosis factor alpha, and IL-6, and comparative transcriptomic analysis of 16-HBE and NR8383 cells revealed that immune pathways and immune cytokines/chemokines were involved in the sensitization of D. farinae exosomes. Taken together, our data demonstrate that D. farinae exosomes are immunogenic and may induce allergic airway inflammation via bronchial epithelial cells and alveolar macrophages. IMPORTANCE Dermatophagoides farinae, a predominant species of house dust mites in China, has displayed pathogenic role in allergic disorders, and exosomes derived from human bronchoalveolar lavage fluid have been strongly associated with allergic respiratory diseases progression. However, the pathogenic role of D. farinae-derived exosomes in allergic airway inflammation has remained unclear until now. This study, for the first time, extracted exosomes from D. farinae, and sequenced their protein cargo and microRNAs using shotgun liquid chromatography-tandem mass spectrometry and small RNA sequencing. D. farinae-derived exosomes trigger allergen-specific immune responses and present satisfactory immunogenicity, as revealed by immunoblotting, Western blotting, and enzyme-linked immunosorbent assay and may induce allergic airway inflammation via bronchial epithelial cells and alveolar macrophages. Our data provide insights into the mechanisms of allergic airway inflammation caused with D. farinae-derived exosomes and the treatment of house dust mite-induced allergic airway inflammation.

NOD1 mediated D. pteronyssinus-induced allergic airway inflammation through RIP2/NF-κB.

BACKGROUND: Dermatophagoides pteronyssinus (D. pteronyssinus) is the main cause of allergic airway inflammation. As the earliest intracytoplasmic pathogen recognition receptors (PRR), NOD1 has been identified as key inflammatory mediator in NOD-like receptor (NLR) family. OBJECTIVE: Our primary aim is to elucidate whether NOD1 and its downstream regulatory proteins mediate D. pteronyssinus-induced allergic airway inflammation. METHODS: Mouse and cell models of D. pteronyssinus-induced allergic airway inflammation were established. NOD1 was inhibited in bronchial epithelium cells (BEAS-2B cells) and mice by cell transfection or application of inhibitor. The change of downstream regulatory proteins was detected by quantitative real-time PCR (qRT-PCR) and Western blot. The relative expression of inflammatory cytokines was evaluated by ELISA. RESULTS: The expression level of NOD1 and its downstream regulatory proteins increased in BEAS-2B cells and mice after treating with D. pteronyssinus extract, followed by the aggravation of inflammatory response. Moreover, inhibition of NOD1 decreased the inflammatory response, which also downregulated the expression of downstream regulatory proteins and inflammatory cytokines. CONCLUSIONS: NOD1 involves in the development of D. pteronyssinus-induced allergic airway inflammation. Inhibition of NOD1 reduces D. pteronyssinus-induced airway inflammation.

Anomalous transverse resistance in 122-type iron-based superconductors.

The study of transverse resistance of superconductors is essential to understand the transition to superconductivity. Here, we investigated the in-plane transverse resistance of Ba0.5K0.5Fe2As2 superconductors, based on ultra-thin micro-bridges fabricated from optimally doped single crystals. An anomalous transverse resistance was found at temperatures around the superconducting transition, although magnetic order or structure distortion are absent in the optimal doping case. With the substitution of magnetic and nonmagnetic impurities into the superconducting layer, the anomalous transverse resistance phenomenon is dramatically enhanced. We find that anisotropic scattering or the superconducting electronic nematic state related with the superconducting transition may contribute to this phenomenon.