PROFILING EXTRACELLULAR MATRIX REMODELING IN AN IN VITRO FIBROBLAST AND EPITHELIAL CELL CO-CULTURE MODEL

Abstract

Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal interstitial lung disease driven by persistent fibroblast activation, abnormal epithelial to mesenchymal signaling and excessive extracellular matrix (ECM) remodeling. Better pre-clinical models are needed to reproduce these processes and to support antifibrotic drug development. This thesis tested whether an in vitro co-culture model can generate ECM biomarker readouts that reflect IPF-like interstitial remodeling and basement membrane (BM) turnover.

A modified Scar-in-a-Jar approach was established using primary normal human lung fibroblasts and human bronchial epithelial cells (Beas-2b). Fibrotic remodeling was induced with transforming growth factor beta (TGF-β) and fibrotic cocktail (FC). Supernatants were collected over time and analyzed by competitive ELISAs for biomarkers of collagen formation (type I, III, IV, VI), fibronectin remodeling and collagen IV degradation. Dose-dependent effects of the anti-fibrotic drugs Nintedanib and Bexotegrast were evaluated in the co-culture setup.
Profibrotic stimulation consistently increased biomarkers linked to interstitial ECM formation, with the strongest responses in 2,000 fibroblasts + 20,000 epithelial cells co-culture, that we selected since in this ratio we could see the additive effect of the epithelial cells in the fibroblast culture. In contrast, collagen IV BM biomarkers showed limited dynamics, suggesting that BM fragment generation and release were not robust under these conditions. In this co-culture setup, Nintedanib reduced fibroblast-associated collagen formation signals, while Bexotegrast produced variable responses.

Overall, the model supports fibroblast-driven interstitial remodeling relevant to IPF and indicated refinements needed to better capture BM turnover and epithelial damage biology.

Popular Abstract

Understanding lung scarring to help develop lifesaving treatments

Imagine breathing through a straw that becomes narrower every year. Something similar happens in idiopathic pulmonary fibrosis (IPF), a serious lung disease in which scar tissue gradually replaces healthy lung tissue. As scarring worsens, breathing becomes increasingly difficult. Current treatments can slow down the disease, but they cannot stop or reverse it.
To develop better treatments, scientists first need to understand how lung scarring develops. This is challenging because the disease progresses slowly over many years and the lungs are difficult to study directly. Laboratory cell systems can help by recreating some of the processes that take place in diseased lungs, allowing scientists to study them under controlled conditions.
In this project, I developed a laboratory model using human lung cells. The goal was to recreate some of the changes that occur during lung scarring and to investigate how different cell types influence each other. The model combined cells that produce and maintain the tissue structure of the lung called fibroblasts with cells that line the airways called epithelial cells. This allowed me to study how these cells work together when exposed to signals promoting scarring.
The results showed that the system could recreate several key processes involved in lung scarring. The cells (fibroblasts) responsible for producing scar tissue increased their production of proteins commonly found in scarred lungs. The presence of airway cells (epithelial cells) also influenced this process, highlighting the importance of interactions between different cell types. Some medicines, known as antifibrotics, can slow down formation of scar tissue. The model was used to test whether two of such drugs could reduce signs of scarring in the laboratory. One of them reduced several signs of scarring, demonstrating that the system could detect treatment responses.

Some aspects of the disease were more difficult to reproduce than others. While the model captured many changes associated with scar tissue formation, it was less successful in recreating changes occurring in the thin supporting layer that helps separate different parts of the lung (the basement membrane). These findings provided valuable information about how the model can be improved in future studies.

By creating a more realistic way to study lung scarring in the laboratory, this work contributes to the development of better research tools for IPF. In the future, improved models may help scientists understand the disease more effectively and support the development of new treatments for patients living with this devastating condition.

• author: Klokova, Xeniya
• supervisor: Kathrin Zeller
• organization: Department of Immunotechnology; Educational programmes, LTH
• course: KIMM01 20261
• year: 2026
• type: H2 - Master's Degree (Two Years)
• subject: Technology and Engineering
• language: English
• id: 9238718
• date added to LUP: 2026-06-16 13:37:13
• date last changed: 2026-06-16 13:37:13