{"title":"Modulation of the Epithelial-mesenchymal transition process by Forkhead Box C2 in the repair of airway epithelium after injury.","authors":"Yudong Wang, Jun Liu","doi":"10.1186/s12931-025-03150-8","DOIUrl":null,"url":null,"abstract":"<p><strong>Background: </strong>Epithelial-mesenchymal transition (EMT) is regarded as a key process in repair of airway epithelium after injury. Forkhead Box C2 (FOXC2) is a transcription factor involved in EMT process, whether it is involved in repair of bronchial epithelium remains unknown.</p><p><strong>Methods: </strong>C57BL/6 mice were subjected to intraperitoneal injection with naphthalene (NAPH; 200 mg/kg) to induce airway injury model. qPCR, immunoblot and FOXC2 immunohistochemistry assays were conducted to detect the expression of FOXC2 in bronchial epithelium. To explore the function of FOXC2 in NAPH-induced airway injury, the mice were given intratracheal administration of shFOXC2- or shNC-lentivirus particles, followed by NAPH treatment. Hematoxylin-and-eosin staining was used to assess the histopathology of the bronchial epithelium. Immunofluorescence analysis of CCSP, a club cell marker confirmed the CCSP expression in bronchial epithelium. Immunoblot and immunofluorescence assays determined the expression of E-cadherin, vimentin, and N-cadherin. In mouse primary bronchial epithelial cells (PBECs), we overexpressed and silenced FOXC2 by lentivirus particles, respectively. Cell migration was analyzed using wound healing assay. Immunoblot assays determined the E-cadherin, vimentin, FN-EDA expression in TGF-β1-induced PBECs. mRNA sequencing (mRNA-seq) and FOXC2 ChIP sequencing (ChIP-seq) to reveal the downstream genes of FOXC2 in TGF-β1-induced PBECs. Luciferase assay, ChIP-PCR and functional rescue experiments were performed to confirm the interaction of FOXC2/formin binding protein 1 (FNBP1) in TGF-β1-induced PBECs.</p><p><strong>Results: </strong>FOXC2 expression was up-regulated in the lung tissues of mice at 2, 3 and 6 days post-NAPH. FOXC2 knockdown in bronchial epithelium of mice delayed CCSP<sup>+</sup> club cell regeneration and normal repair of the airway epithelium within 14 days after injury. Knockdown of FOXC2 increased E-cadherin but decreased vimentin and N-cadherin, EMT markers during early phase after injury. In vitro, knockdown of endogenous FOXC2 repressed the migration of cells and increased TGF-β1-induced E-cadherin but decreased vimentin, N-cadherin and FN-EDA. Exogenous FOXC2 addition exerted opposite effects. Furthermore, mRNA-seq and FOXC2 ChIP-seq revealed that FNBP1 might be a downstream target of FOXC2. Overexpression of FNBP1 reversed the inhibitory role of FOXC2 knockdown in EMT.</p><p><strong>Conclusions: </strong>These data highlight the important function of FOXC2 as a regulator in repair of bronchial epithelium after injury.</p>","PeriodicalId":49131,"journal":{"name":"Respiratory Research","volume":"26 1","pages":"96"},"PeriodicalIF":5.8000,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11895206/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Respiratory Research","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1186/s12931-025-03150-8","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"Medicine","Score":null,"Total":0}
引用次数: 0
Abstract
Background: Epithelial-mesenchymal transition (EMT) is regarded as a key process in repair of airway epithelium after injury. Forkhead Box C2 (FOXC2) is a transcription factor involved in EMT process, whether it is involved in repair of bronchial epithelium remains unknown.
Methods: C57BL/6 mice were subjected to intraperitoneal injection with naphthalene (NAPH; 200 mg/kg) to induce airway injury model. qPCR, immunoblot and FOXC2 immunohistochemistry assays were conducted to detect the expression of FOXC2 in bronchial epithelium. To explore the function of FOXC2 in NAPH-induced airway injury, the mice were given intratracheal administration of shFOXC2- or shNC-lentivirus particles, followed by NAPH treatment. Hematoxylin-and-eosin staining was used to assess the histopathology of the bronchial epithelium. Immunofluorescence analysis of CCSP, a club cell marker confirmed the CCSP expression in bronchial epithelium. Immunoblot and immunofluorescence assays determined the expression of E-cadherin, vimentin, and N-cadherin. In mouse primary bronchial epithelial cells (PBECs), we overexpressed and silenced FOXC2 by lentivirus particles, respectively. Cell migration was analyzed using wound healing assay. Immunoblot assays determined the E-cadherin, vimentin, FN-EDA expression in TGF-β1-induced PBECs. mRNA sequencing (mRNA-seq) and FOXC2 ChIP sequencing (ChIP-seq) to reveal the downstream genes of FOXC2 in TGF-β1-induced PBECs. Luciferase assay, ChIP-PCR and functional rescue experiments were performed to confirm the interaction of FOXC2/formin binding protein 1 (FNBP1) in TGF-β1-induced PBECs.
Results: FOXC2 expression was up-regulated in the lung tissues of mice at 2, 3 and 6 days post-NAPH. FOXC2 knockdown in bronchial epithelium of mice delayed CCSP+ club cell regeneration and normal repair of the airway epithelium within 14 days after injury. Knockdown of FOXC2 increased E-cadherin but decreased vimentin and N-cadherin, EMT markers during early phase after injury. In vitro, knockdown of endogenous FOXC2 repressed the migration of cells and increased TGF-β1-induced E-cadherin but decreased vimentin, N-cadherin and FN-EDA. Exogenous FOXC2 addition exerted opposite effects. Furthermore, mRNA-seq and FOXC2 ChIP-seq revealed that FNBP1 might be a downstream target of FOXC2. Overexpression of FNBP1 reversed the inhibitory role of FOXC2 knockdown in EMT.
Conclusions: These data highlight the important function of FOXC2 as a regulator in repair of bronchial epithelium after injury.
期刊介绍:
Respiratory Research publishes high-quality clinical and basic research, review and commentary articles on all aspects of respiratory medicine and related diseases.
As the leading fully open access journal in the field, Respiratory Research provides an essential resource for pulmonologists, allergists, immunologists and other physicians, researchers, healthcare workers and medical students with worldwide dissemination of articles resulting in high visibility and generating international discussion.
Topics of specific interest include asthma, chronic obstructive pulmonary disease, cystic fibrosis, genetics, infectious diseases, interstitial lung diseases, lung development, lung tumors, occupational and environmental factors, pulmonary circulation, pulmonary pharmacology and therapeutics, respiratory immunology, respiratory physiology, and sleep-related respiratory problems.