The Center for Alternatives to Animal Testing is an academic center affiliated with the Division of Toxicological Sciences in the Department of Environmental Health Sciences of the Johns Hopkins University Bloomberg School of Public Health.

 

Johns Hopkins School of Public Health

Research Grants 2001-2002

Rhythmically Stretching Dynamic Cell Culture: An in vitro Model to Study Particle Cell Injury

Akira, Tsuda, PhD
Harvard School of Public Health, Boston, Massachusetts

Exposure to airborne particulates is strongly associated with lung injury, but the molecular and cellular mechanisms responsible for this association are not fully understood. In this project, we are investigating a new aspect of particle-induced lung pathogenesis: the effect of the physical insults exerted by particles on alveolar epithelial cells. We hypothesize that these physical stimuli may be greatly enhanced by cyclic motion of the alveolar epithelial cells associated with breathing, and may trigger subsequent cell responses. This hypothesis is tested in vitro in a model employing monolayers of the human alveolar epithelial cell line A549 are rhythmically stretched by a cell stretcher device with physiologically relevant tidal breathing conditions, while these cells are exposed to various test particles, such as asbestos fibers. In this year, we will investigate the effects of cyclic cell stretching on particle internalization by the human alveolar epithelial cells, and characterize the overall gene expression profiles of the alveolar cells exposed to particles while the cells are rhythmically stretched by using a state-of-the art DNA microarray technology. The role of receptor-mediated interactions between protein-coated particles and rhythmically moving cell surface receptors (e.g., integrin) will also be assessed. The results of this study would help us to understand how physical insults exerted on the expandingand-contracting alveolar epithelial cell surface lead to lung injury.