ObjectiveThe aim of this study is to explore the effects of early postnatal hyperoxia exposure combined with early ovalbumin (OVA) sensitization on lung inflammation and bacterial flora in neonatal mice on a juvenile mouse model of asthma.MethodsThirty-two newborn female C57BL/6 J mice were randomly divided into four groups, which including room air+phosphate-buffered saline (PBS) group, hyperoxia+PBS group, room air+OVA group, and hyperoxia+OVA group, according to the hyperoxia exposure and/or OVA induction. Mice were exposed to either 95% O2 or room air for 7 days after birth; after 7 days, they were exposed to air and received an intraperitoneal injection of OVA suspension or PBS solution on postnatal days 21 (P21) and 28 (P28). From P36 to P42, the mice were allowed to inhale of 1% OVA or 0.9% NaCl solution. The mice were observed after the last excitation. HE staining was performed to observe the pathological changes in lung tissues. Wright-Giemsa staining was used to perform bronchoalveolar lavage fluid (BALF) leukocyte sorting. Enzyme-linked immunosorbent assay was used to determined the cytokines levels of interleukin (IL)-2, IL-5, IL-13, IL-17A, and IL-10 and serum IgE levels in BALF. Additionally, 16S rRNA sequencing was used to analyze the characteristics of lung microbiota.ResultsMice in the hyperoxia+OVA group showed asthma-like symptoms. HE staining results revealed a significant thickening of the airway wall and airway inflammation. BALF analysis of cellular components showed significant increases in total leukocyte and eosinophil counts and the levels of cytokines related to Th2 (IL-5 and IL-13) and Th17 (IL-17A); 16S rRNA sequencing revealed that the main members of the pulmonary microflora were Actinobacteriota, Proteobacteria, Firmicutes, and Bacteroidota at the phylum level. In addition, the bacteria with a major role were Acinetobacter and Moraxellaceae in the O2 + OVA group.ConclusionThe mouse suffering from postnatal hyperoxia exposure and early OVA sensitization, changes in symptoms, pathology, leukocyte and eosinophil counts, and levels of different T-cell cytokines in BALF and lung microbiota, which may provide a basis for the establishment of a juvenile mouse model of asthma.

Objective: to evaluate the effect of N6-methyladenosine (m6A) RNA methylation regulators on the development of bronchopulmonary dysplasia (BPD). Methods: Transcriptome data related BPD was downloaded from the GEO. Differentially expressed m6A methylation regulators between BPD and control group were identified. Consensus clustering was conducted for the classification of BPD and its association with the phenotypes were conducted. Differentially expressed genes (DEGs) and immune related DEGs (DEMGs) analysis was performed. The GSEA, GO and KEGG were applied to interpret the functional enrichments. The composition of immune cell subtypes in BPD subsets was predicted by CIBERSORT analysis. Results: Compared with control group, the alteration of most m6A regulators expression were detected, especially for IGF2BP1/2/3. The BPD was classified into 2 subsets, of which cluster 1 was correlated with severe BPD. Furthermore, the functional enrichment results showed a disturbed immune-related signaling pathway. The CIBERSORT analysis found that the proportion of immune cell subsets changed between cluster1 and cluster 2. Conclusions: Our study revealed an implication of m6A methylation regulators for the development of BPD, which might provide a novel insight for the diagnosis and treatment for BPD.

Objective: Bronchopulmonary dysplasia (BPD) is a common complication of prematurity and has no specific treatment option. Moreover, inflammation and fibrosis play a vital role in the development of BPD. Thus, this study aimed to explore the role of the anti-inflammatory and anti-fibrotic drug cryptotanshinone (CTS) in the treatment of inflammation and fibrosis in BPD.Methods:In vivo, Sprague–Dawley rats (male) were divided into air, hyperoxia and CTS groups with different dose interventions (7.5, 15, and 30 mg/kg). A BPD rat model was induced by continuous inhalation of hyperoxia (95%) for 7 days, during which different doses of CTS were injected intraperitoneally. Furthermore, histological examination, hydroxyproline content measurement, Western blot and real-time quantitative polymerase chain reaction were used to detect the levels of inflammation and fibrosis in the tissues. RAW264.7 cells exposed to 95% oxygen were collected and co-cultured with fibroblasts to determine the expression levels of α-SMA, collagen-Ⅰ and MMPs. The levels of pro-inflammatory cytokines such as TNF-α, IL-6 and pro-fibrotic factor TGF-β1 in the supernatants were measured using enzyme-linked immunosorbent assay.Results: Haematoxylin and eosin staining revealed that CTS reduced the inflammatory response in rat lungs. Masson staining revealed that CTS alleviated the level of pulmonary fibrosis. CTS also reduced the levels of TNF-α, IL-6 and TGF-β1 along with the expression of the fibrosis marker α-SMA in lung tissue. Similarly, in vitro analysis revealed that CTS decreased the levels of TNF-α, IL-6 and TGF-β1 expressed in RAW 264.7 cells, and reduced α-SMA, collagen-Ⅰ, MMPs concentrations in HFL-1 cells co-cultured with the supernatant of RAW264.7 cells after hyperoxia.Conclusion: CTS can attenuate the hyperoxia-induced inflammatory response and the level of fibrosis by regulating the levels of inflammatory factors and fibrotic factor TGF-β1 expressed by macrophages, thereby highlighting the therapeutic potential of CTS in the treatment of BPD.