Using in vitro and ex vivo models of lung injury as a platform to identify and study mechanisms driving lung repair
File(s)
Author(s)
Bankole, Esther
Type
Thesis
Abstract
Current treatments for respiratory diseases, including chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF) and asthma are not curative, highlighting an unmet need for novel therapies. Our limited understanding of signalling pathways involved in lung repair, and lack of advanced models replicating the complexity of the human lung poses a challenge. Developmental signalling pathways are reactivated during lung repair; modulating these pathways offers potential for regenerative therapeutics. This PhD tested the hypothesis that pathways essential for lung development play critical roles in alveolar repair and/or regeneration.
WNT, retinoic acid (RA), and Sonic Hedgehog (SHH) pathways were screened using in vitro wound healing assays to investigate their effects on epithelial and endothelial cell migration during repair. Based on these assays, SHH was selected for further investigation. SHH is critical for lung development, particularly branching morphogenesis and fibroblast expansion in the adult lung, however, its role in repair remains poorly understood. I demonstrated that SHH modulates fibroblasts, SHH treatment increased migration in human lung fibroblasts (HLFs) while co-culture of HLF with alveolar epithelial cells (A549) increased migration of both cell types. Using the ex vivo Acid injury and repair (AIR) model, SHH increased vimentin+ fibroblasts in acid-injured regions of AIR-PCLS and was associated with myofibroblast (a-SMA) and lipofibroblasts (ADRP) expression. The human model (hAIR) was established as part of this thesis, SHH treatment similarly increased ADRP+ cells in hAIR-PCLS.
To explore whether SHH signalling contributes to disease pathology, I analysed a cohort of emphysematous tissue samples and observed upregulation of SHH and downregulation of HHIP, suggesting changes in pathway activation. These findings were supported by COPD Cell Atlas data, showing consistent changes in SHH pathway activity across multiple cell populations. Collectively, these findings support a role for SHH in lung repair and highlights its potential as a regenerative therapeutic target.
WNT, retinoic acid (RA), and Sonic Hedgehog (SHH) pathways were screened using in vitro wound healing assays to investigate their effects on epithelial and endothelial cell migration during repair. Based on these assays, SHH was selected for further investigation. SHH is critical for lung development, particularly branching morphogenesis and fibroblast expansion in the adult lung, however, its role in repair remains poorly understood. I demonstrated that SHH modulates fibroblasts, SHH treatment increased migration in human lung fibroblasts (HLFs) while co-culture of HLF with alveolar epithelial cells (A549) increased migration of both cell types. Using the ex vivo Acid injury and repair (AIR) model, SHH increased vimentin+ fibroblasts in acid-injured regions of AIR-PCLS and was associated with myofibroblast (a-SMA) and lipofibroblasts (ADRP) expression. The human model (hAIR) was established as part of this thesis, SHH treatment similarly increased ADRP+ cells in hAIR-PCLS.
To explore whether SHH signalling contributes to disease pathology, I analysed a cohort of emphysematous tissue samples and observed upregulation of SHH and downregulation of HHIP, suggesting changes in pathway activation. These findings were supported by COPD Cell Atlas data, showing consistent changes in SHH pathway activity across multiple cell populations. Collectively, these findings support a role for SHH in lung repair and highlights its potential as a regenerative therapeutic target.
Date Issued
2025-10-10
Date Awarded
01/02/2026
Advisor
Dean, Charlotte
Tetley, Terry
Sponsor
NHLI Foundation
Publisher Department
National Heart & Lung Institute
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)