The use of cultured human alveolar basal cells to mimic honeycomb formation in idiopathic pulmonary fibrosis

Sabrina Blumer; Petra Khan; Nataliia Artysh; Linda Plappert; Spasenija Savic; Lars Knudsen; Danny Jonigk; Mark P Kuehnel; Antje Prasse; Katrin E Hostettler

doi:10.1186/s12931-024-02666-9

The use of cultured human alveolar basal cells to mimic honeycomb formation in idiopathic pulmonary fibrosis

Respir Res. 2024 Jan 10;25(1):26. doi: 10.1186/s12931-024-02666-9.

Authors

Sabrina Blumer¹, Petra Khan¹, Nataliia Artysh^{2

3}, Linda Plappert², Spasenija Savic⁴, Lars Knudsen^{5

6}, Danny Jonigk^{7

6}, Mark P Kuehnel^{7

6}, Antje Prasse^{2

3

6}, Katrin E Hostettler⁸

Affiliations

¹ Department of Biomedicine and Clinics of Respiratory Medicine, University Hospital Basel, University of Basel, Hebelstrasse 20, 4031, Basel, Switzerland.
² Fraunhofer Institute for Toxicology and Experimental Medicine, 30625, Hannover, Germany.
³ Department of Pulmonology and Infectious Diseases, Hannover Medical School, Hannover, Germany.
⁴ Institute of Medical Genetics and Pathology, University Hospital Basel, University of Basel, 4031, Basel, Switzerland.
⁵ Institute of Functional and Applied Anatomy, Hannover Medical School, 30625, Hannover, Germany.
⁶ Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), 30625, Hannover, Germany.
⁷ Institute of Pathology, Medical Faculty, RWTH University Aachen, 52074, Aachen, Germany.
⁸ Department of Biomedicine and Clinics of Respiratory Medicine, University Hospital Basel, University of Basel, Hebelstrasse 20, 4031, Basel, Switzerland. Katrin.Hostettler@usb.ch.

Abstract

Background: Honeycomb cysts (HC) within the alveolar region are distinct histopathological features in the lungs of idiopathic pulmonary fibrosis (IPF) patients. HC are lined with a single-or stratified layer of basal cells (BC), or with a bronchiolar-like epithelium composed of basal-, ciliated- and secretory epithelial cells. By using cultured IPF patient-derived alveolar BC, we aimed to establish an in vitro- and in vivo model to mimic HC formation in IPF. We (1) optimized conditions to culture and propagate IPF patient-derived alveolar BC, (2) cultured the cells on an air liquid interface (ALI) or in a three dimensional (3D) organoid model, and (3) investigated the cells` behavior after instillation into bleomycin-challenged mice.

Methods: Alveolar BC were cultured from peripheral IPF lung tissue and grown on tissue-culture treated plastic, an ALI, or in a 3D organoid model. Furthermore, cells were instilled into bleomycin-challenged NRG mice. Samples were analyzed by TaqMan RT-PCR, immunoblotting, immunocytochemistry/immunofluorescence (ICC/IF), or immunohistochemistry (IHC)/IF. Mann-Whitney tests were performed using GraphPad Prism software.

Results: Cultured alveolar BC showed high expression of canonical basal cell markers (TP63, keratin (KRT)5, KRT14, KRT17), robust proliferation, and wound closure capacity. The cells could be cryopreserved and propagated for up to four passages without a significant loss of basal cell markers. When cultured on an ALI or in a 3D organoid model, alveolar BC differentiated to ciliated- and secretory epithelial cells. When instilled into bleomycin-challenged mice, human alveolar BC cells formed HC-like structures composed of human basal-, and secretory epithelial cells within the mouse parenchyma.

Conclusion: IPF patient-derived alveolar BC on an ALI, in 3D organoids or after instillation into bleomycin-challenged mice form HC-like structures that closely resemble HC within the IPF lung. These models therefore represent powerful tools to study honeycomb formation, and its potential therapeutic inhibition in IPF.

Keywords: ALI; Alveolar basal cells; Honeycomb cysts; Humanized mouse model; IPF; Mucociliary differentiation; Organoids.

MeSH terms

Alveolar Epithelial Cells
Animals
Bleomycin / toxicity
Epithelial Cells
Epithelium
Humans
Idiopathic Pulmonary Fibrosis* / chemically induced
Mice

Substances

Bleomycin

Grants and funding

310030_192536/Swiss National Research Foundation