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Idiopathic pulmonary fibrosis (IPF) is a devastating lung disease that progressively and irreversibly alters the lung parenchyma, eventually leading to respiratory failure. The study of this disease has been historically challenging due to the myriad of complex processes that contribute to fibrogenesis and the inherent difficulty in accurately recreating the human pulmonary environment in vitro . Here, we describe a poly(ethylene glycol) PEG hydrogel-based three-dimensional model for the co-culture of primary murine pulmonary fibroblasts and alveolar epithelial cells that reproduces the micro-architecture, cell placement, and mechanical properties of healthy and fibrotic lung tissue. Co-cultured cells retained normal levels of viability up to at least three weeks and displayed differentiation patterns observed in vivo during IPF progression. Interrogation of protein and gene expression within this model showed that myofibroblast activation required both extracellular mechanical cues and the presence of alveolar epithelial cells. Differences in gene expression indicated that cellular co-culture induced TGF-β signaling and proliferative gene expression, while microenvironmental stiffness upregulated the expression of genes related to cell–ECM interactions. This biomaterial-based cell culture system serves as a significant step forward in the accurate recapitulation of human lung tissue in vitro and highlights the need to incorporate multiple factors that work together synergistically in vivo into models of lung biology of health and disease.
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A scalable 3D tissue culture pipeline to enable functional therapeutic screening for pulmonary fibrosis
Idiopathic pulmonary fibrosis (IPF) is a lethal lung disease targeting the alveolar gas exchange apparatus, leading to death by asphyxiation. IPF progresses on a tissue scale through aberrant matrix remodeling, enhanced cell contraction, and subsequent microenvironment densification. Although two pharmaceuticals modestly slow progression, IPF patient survival averages less than 5 years. A major impediment to therapeutic development is the lack of high-fidelity models that account for the fibrotic microenvironment. Our goal is to create a three-dimensional (3D) platform to enable lung fibrosis studies and recapitulate IPF tissue features. We demonstrate that normal lung fibroblasts encapsulated in collagen microspheres can be pushed toward an activated phenotype, treated with FDA-approved therapies, and their fibrotic function quantified using imaging assays (extracellular matrix deposition, contractile protein expression, and microenvironment compaction). Highlighting the system's utility, we further show that fibroblasts isolated from IPF patient lungs maintain fibrotic phenotypes and manifest reduced fibrotic function when treated with epigenetic modifiers. Our system enables enhanced screening due to improved predictability and fidelity compared to 2D systems combined with superior tractability and throughput compared to 3D systems.
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- Award ID(s):
- 1704332
- PAR ID:
- 10584167
- Publisher / Repository:
- American Institute of Physics
- Date Published:
- Journal Name:
- APL Bioengineering
- Volume:
- 5
- Issue:
- 4
- ISSN:
- 2473-2877
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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