Autophagy plays critical roles in airway inflammation and fibrosis-mediated airway remodeling and many factors including proinflammatory cytokines and inflammation related pathways are involved in the process. The aim of the present study was to examine the role of epithelial microRNAs (miRNAs) in autophagy-mediated airway remodeling and to identify the factors involved and the underlying mechanisms. Serum miR-34/449, inflammatory factors, and autophagy and fibrosis-related proteins were determined by real-time PCR, enzyme-linked immunosorbent assay and western blotting in 46 subjects with asthma and 10 controls and in the lung epithelial cell line BEAS-2B induced with IL-13 and treated with miRNA mimics. Luciferase assays were used to verify IGFBP-3 as a target of miR-34/449, and immunohistochemistry, immunofluorescence and co-immunoprecipitation were used in vitro and in vivo study. miR-34/449 were downregulated in patients with asthma in parallel with the upregulation of autophagy-related proteins. Proinflammatory factors and fibrosis-related proteins were significantly higher in asthma patients than in healthy controls. IL-13 induction promoted autophagy and upregulated miR-34/449 in BEAS-2B cells, and these effects were restored by IGFBP-3 silencing. miR-34/449 overexpression suppressed autophagy, decreased fibrosis, activated Akt, downregulated fibrosis-related factors, and downregulated proinflammatory cytokines and nuclear factor κB by targeting IGFBP-3. In vivo experiments showed that miR-34/449 overexpression was associated with Nur77 nuclear translocation and IGFBP-3 downregulation in parallel with decreased airway remodeling by decreased autophagy. miR-34/449 are potential biomarkers and therapeutic targets in asthma. miR-34/449 may contribute to airway inflammation and fibrosis by modulating IGFBP-3 mediated autophagy activation.

Asthma is the most common chronic disease and is characterized by airway remodeling and chronic inflammation. Increasingly, studies have found that the activation and M1 phenotypic transformation of macrophages play important roles in asthma progress, including airway remodeling. However, the reversal of M1 macrophages to the M2 phenotype has been shown to attenuate airway remodeling. Exosomes are nano-sized extracellular vesicles derived from endosomes; they play direct roles in governing physiological and pathological conditions by the intracellular transfer of bioactive cargo, such as proteins, enzymes, nucleic acids (microRNA [miRNA], mRNA, DNA), and metabolites. However, transfer mechanisms are unclear. To uncover potential therapeutic mechanisms, we constructed an ovalbumin-induced asthma mouse model and lipopolysaccharide-induced RAW264.7 macrophages cells. High-throughput sequencing showed that mmu_circ_0001359 was downregulated in asthmatic mice when compared with normal mice. Adipose-derived stem cell (ADSC)-exosome treatment suppressed inflammatory cytokine expression by the conversion of M1 macrophages to the M2 phenotype, under lipopolysaccharide-induced conditions. Exosomes from mmu_circ_0001359 overexpression in ADSCs increased therapeutic effects, in terms of cytokine expression, when compared with wild-type exosomes. Luciferase reporter assays confirmed that exosomes from mmu_circ_0001359-modified ADSCs attenuated airway remodeling by enhancing FoxO1 signaling-mediated M2-like macrophage activation, via sponging miR-183-5p. In conclusion, mmu_circ_0001359-enriched exosomes attenuated airway remodeling by promoting M2-like macrophages.

True sea snakes (Hydrophiini) are among the last and most successful clades of vertebrates that show secondary marine adaptation, exhibiting diverse phenotypic traits and lethal venom systems. To better understand their evolution, we generated the first chromosome-level genomes of two representative Hydrophiini snakes, Hydrophis cyanocinctus and H. curtus. Through comparative genomics we identified a great expansion of the underwater olfaction-related V2R gene family, consisting of more than 1,000 copies in both snakes. A series of chromosome rearrangements and genomic structural variations were recognized, including large inversions longer than 30 megabase (Mb) on sex chromosomes which potentially affect key functional genes associated with differentiated phenotypes between the two species. By integrating multiomics we found a significant loss of the major weapon for elapid predation, three-finger toxin genes, which displayed a dosage effect in H. curtus. These genetic changes may imply mechanisms that drove the divergent evolution of adaptive traits including prey preferences between the two closely related snakes. Our reference-quality sea snake genomes also enrich the repositories for addressing important issues on the evolution of marine tetrapods, and provide a resource for discovering marine-derived biological products.

Bronchial asthma is a common chronic airway disease, and long-term management of asthma is the focus and difficulty of clinical treatment. Glucocorticoids are often used as the first choice for the treatment of asthma. However, the occurrence of hormone dependence, hormone resistance, local and systemic adverse reactions caused by hormone application also brings problems for the treatment of asthma. Finding safe and effective new therapeutic drugs is an important research direction at present. Icariin is the effective ingredient of traditional Chinese medicine Epimedium. It has various biological activities such as anti-inflammatory, anti-oxidative stress, and immune regulation. It has high safety and has a wide range of clinical applications. Icariin has the characteristics of multi-target intervention in the treatment of asthma. This article reviews recent studies in order to provide new research directions for further therapeutic drug development.