Primary cilia dyskinesia (PCD) is a rare genetic disease caused by ciliary structural or functional defects. It causes severe outcomes in patients, including recurrent upper and lower airway infections, progressive lung failure, and randomization of heterotaxy. To date, although 50 genes have been shown to be responsible for PCD, the etiology remains elusive. Meanwhile, owing to the lack of a model mimicking the pathogenesis that can be used as a drug screening platform, thereby slowing the development of related therapies. In the current study, we identified compound mutation of DNAH9 in a patient with PCD with the following clinical features: recurrent respiratory tract infections, low lung function, and ultrastructural defects of the outer dynein arms (ODAs). Bioinformatic analysis, structure simulation assay, and western blot analysis showed that the mutations affected the structure and expression of DNAH9 protein. Dnah9 knock-down (KD) mice recapitulated the patient phenotypes, including low lung function, mucin accumulation, and increased immune cell infiltration. Immunostaining, western blot, and co-immunoprecipitation analyses were performed to clarify that DNAH9 interacted with CCDC114/GAS8 and diminished their protein levels. Furthermore, we constructed an airway organoid of Dnah9 KD mice and discovered that it could mimic the key features of the PCD phenotypes. We then used organoid as a drug screening model to identify mitochondrial-targeting drugs that can partially elevate cilia beating in Dnah9 KD organoid. Collectively, our results demonstrated that Dnah9 KD mice and an organoid model can recapture the clinical features of patients with PCD and provide an excellent drug screening platform for human ciliopathies.

Dynein axonemal heavy chain 5 (DNAH5) is the most mutated gene in primary ciliary dyskinesia (PCD), leading to abnormal cilia ultrastructure and function. Few studies have revealed the genetic characteristics and pathogenetic mechanisms of PCD caused by DNAH5 mutation. Here, we established a child PCD airway organoid directly from the bronchoscopic biopsy of a patient with the DNAH5 mutation. The motile cilia in the organoid were observed and could be stably maintained for an extended time. We further found abnormal ciliary function and a decreased immune response caused by the DNAH5 mutation through single-cell RNA sequencing (scRNA-Seq) and proteomic analyses. Additionally, the directed induction of the ciliated cells, regulated by TGF-β/BMP and the Notch pathway, also increased the expression of inflammatory cytokines. Taken together, these results demonstrated that the combination of multiomics analysis and organoid modelling could reveal the close connection between the immune response and the DNAH5 gene.

Background: Asthma is a chronic lung disease characterized by reversible inflammation of the airways. The imbalance of Th1/Th2 cells plays a significant role in the mechanisms of asthma. The aim of this study was to identify asthma-related key genes and functionally enriched pathways in a Th2-high group by using weighted gene coexpression network analysis (WGCNA). Methods: The gene expression profiles of GSE4302, which included 42 asthma patients and 28 controls, were selected from the Gene Expression Omnibus (GEO). A gene network was constructed, and genes were classified into different modules using WGCNA. Gene ontology (GO) was performed to further explore the potential function of the genes in the most related module. In addition, the expression profile and diagnostic capacity (ROC curve) of hub genes of interest were verified by dataset GSE67472. Results: In dataset GSE4302, subjects with asthma were divided into Th2-high and Th2-low groups according to the expression of the SERPINB2, POSTN and CLCA1 genes. A weighted gene coexpression network was constructed, and genes were classified into 7 modules. Among them, the red module was most closely associated with Th2-high asthma, which contained 60 genes. These genes were significantly enriched in different biological processes and molecular functions. A total of 8 hub genes (TPSB2, CPA3, ITLN1, CST1, SERPINB10, CEACAM5, CHD26 and P2RY14) were identified, and the expression levels of these genes (except TPSB2) were confirmed in dataset GSE67472. ROC curve analysis validated that the expression of these 8 genes exhibited excellent diagnostic efficiency for Th2-high asthma and Th2-low asthma. Conclusions: The study provides a novel perspective on Th2-high asthma by WGCNA, and the hub genes and potential pathways involved may be beneficial for the diagnosis and management of Th2-high asthma.

Background: The nasal epithelium, as part of a continuous and integrated airway epithelium, provides a more accessible sample source than the bronchial epithelium. However, the similarities and differences in gene expression patterns and immune responses between these two sites have not been extensively studied. Results: Four lines of matched nasal and bronchial airway epithelial cells obtained from the four patients were embedded in Matrigel and cultured in thechemically defined medium to generate patient-derived nasal organoids (NO) and bronchial organoids (BO). Histologic examination of nasal organoid tissue revealed high similarity and a reduced ciliary beat frequency compared to bronchial organoid tissue. Whole exome sequencing revealed that over 99% of single nucleotides were shared between the NO and matched BO and there was a 95% overlap in their RNA transcriptomes. RNA sequencing analysis of differentially expressed genes indicated a significant reduction in the immune response in NO. RSV infection revealed more productive replication in NO, with a downregulated immune pathway identified by RNA sequencing analysis and upregulated levels of pro-inflammatory cytokines in culture supernatants in NO compared to BO. Conclusions: NO and BO serve as robust in vitro models, faithfully recapitulating the biological characteristics of upper respiratory epithelial cells. The different regions of respiratory epithelial cells exhibit distinct immune responses, underscoring their complementary roles in exploring airway immune mechanisms and disease pathophysiology.

This study aims to review the clinical characteristics, therapeutic response and outcome of idiopathic pulmonary hemosiderosis (IPH), and discover the risk factors for recurrence in children with IPH, which will be helpful for the early diagnosis and reasonable treatment of this disease. Children with a diagnosis of IPH were enrolled in the study. Clinical data of the children were collected and analysed. A total of 32 patients with regular follow-up after diagnosis were included in this study. Anaemia, cough and haemoptysis constituted the most common initial symptoms of the disease, and the incidences were 90.6%, 75% and 56.2%, respectively. The mean gap between the onset of symptoms and diagnosis was 5 (0.25-36) months. Most of the children experienced remission (complete and partial remission) over the course of 6 months of treatment, but 19 of the children experienced relapse. The causes of disease recurrence included respiratory tract infection (37.5%), corticosteroid (CS) reduction (18.8%), and irregular medication (6.3%). Interestingly, we found that children with history of allergy (HR 4.255, 1.107–16.356) tended to experience disease recurrence (p = 0.01). Cough and anaemia are the most common symptoms in children with IPH. The recurrence rate of this disease is high, and respiratory tract infection is the most common cause of its recurrence. High-dose CS impluse therapy cannot reduce the recurrence rate of the disease. Allergic history was an import factor associated with disease recurrence. This study is a retrospective and observational study, which does not involve human specimens or clinical intervention. Therefore, clinical trial registration is not required, and there is no clinical trial number. However, the study was approved by the Institutional Review Board/Ethics Committee affiliated with West China Second University Hospital, Sichuan University (Ethics review number 2022074).