Our lungs are covered with a thin fluid layer, which contains a surface-active substance, called “surfactant”. The primary function of surfactant is to lower the surface tension in the alveoli to ensure proper expansion while breathing.
The lung surfactant also plays an important role in removing inhaled, foreign particle from the lungs by covering them in liquid. Foreign particles that are not removed in this way, are able to come in contact with the cells lining the alveoli, namely lung epithelial cells and macrophages. Macrophages represent the body’s “cleaning personnel” as they eat the unwanted substances and thus remove them. Lung epithelial cells create a physical barrier for inhaled substances and produce the lung surfactant which plays an important role in the interplay between the lung epithelial cells and the macrophages.
The interplay between particles, lung surfactant and the different lung cells can lead to an activation of these cells and eventually result in inflammatory reactions in the lung.
This project will contribute to the understanding of the interactions between particles and lung cells by studying the mechanisms of these interactions, the particle transport through the lung epithelium and the role of surfactant in the onset of inflammatory conditions in exposed workers.
Specifically, the aims of the project are the following:
- How are foreign particles taken up in lung cells and what role does lung surfactant have in this process?
- Characterize the fate of the particles in the lungs over a longer period (bioprocessing): What happens to the particles? Where do they end up in the cells?
- Which cellular and molecular mechanisms are induced by foreign particles in lung cells? Do these particles induce adverse effects?
To answer these questions, we will characterize the particle-cell interactions and the bioprocessing of the particles by using a cell culture exposure model at air-liquid-interface (ALI). We will also characterize the physicochemical properties of the particles and study the cellular uptake and bioprocessing in the lungs of exposed animals. Here, we will assess inflammatory reactions in the lungs, but also other organs, following long-term particle exposure of mice.
We also aim to identify new, relevant biomarkers for pulmonary particle exposure.
In this project, we will use model particles that are relevant for the Norwegian industry, for example titanium dioxide particles. The results from this project can be applied to evaluate other types of particle exposure in melt and iron alloy industry, tunnel construction or stone drilling.
- Johanna Samulin-Erdem (project manager)
- Susann Wolf
- Shan Narui
- Dag Ellingsen
- Torunn K. Ervik
National Institute of Occupational Safety and Health (NIOSH), USA
University of Kentucky, USA
Helmholtz Zentrum, Germany
STAMI and NIOSH