Pretreatment of aged mice with retinoic acid supports alveolar regeneration via upregulation of reciprocal PDGFA signalling
Year: 2021
Type: article
Abstract: OBJECTIVES: Idiopathic pulmonary fibrosis (IPF) primarily affects the aged population and is characterised by failure of alveolar regeneration, leading to loss of alveolar type 1 (AT1) cells. Aged mouse models of lung repair have demonstrated that regeneration fails with increased age. Mouse and rat lung repair models have shown retinoic acid (RA) treatment can restore alveolar regeneration. Herein, we seek to determine the signalling mechanisms that become activated on RA treatment prior to injury, which support alveolar differentiation. DESIGN: Partial pneumonectomy lung injury model and next-generation sequencing of sorted cell populations were used to uncover molecular targets regulating alveolar repair. In vitro organoids generated from epithelial cells of mouse or patient with IPF co-cultured with young, aged or RA-pretreated murine fibroblasts were used to test potential targets. MAIN OUTCOME MEASUREMENTS: Known alveolar epithelial cell differentiation markers, including HOPX and AGER for AT1 cells, were used to assess outcome of treatments. RESULTS: Gene expression analysis of sorted fibroblasts and epithelial cells isolated from lungs of young, aged and RA-pretreated aged mice predicted increased platelet-derived growth factor subunit A (PDGFA) signalling that coincided with regeneration and alveolar epithelial differentiation. Addition of PDGFA induced AT1 and AT2 differentiation in both mouse and human IPF lung organoids generated with aged fibroblasts, and PDGFA monoclonal antibody blocked AT1 cell differentiation in organoids generated with young murine fibroblasts. CONCLUSIONS: Our data support the concept that RA indirectly induces reciprocal PDGFA signalling, which activates regenerative fibroblasts that support alveolar epithelial cell differentiation and repair, providing a potential therapeutic strategy to influence the pathogenesis of IPF.
Source: Thorax
Language: English
Subfield: Pulmonary and Respiratory Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
Awards: Editing Alveolar Progenitor Cells for Correction of Monogenic Disease, G2688237320, G302374502, G327302100, Epithelial cell activation of fibroblasts in pulmonary fibrosis, G4152714799, G4302707486, G4838964745, G4950275388, Matrix fibroblasts are required for alveolar homeostasis and regrowth, Uterine signaling networks in the pathogenesis of pulmonary lymphangioleiomyomatosis (LAM), Molecular Atlas of Lung Development - Data Coordinating Center, G8723306597
OpenAlex ID: W3121970570