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 2000-2001

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

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

As the lung represents an enormously large surface area exposed to the environment, it is not surprising that exposure to airborne particulates is strongly associated with lung injury. However, the molecular and cellular mechanisms responsible for the particle-induced pathogenesis are not fully understood. We hypothesize that the mechanical contact between particles and the epithelial cells plays an important role in lung injury, and that the physical stimuli exerted on cells by particles may be greatly enhanced by the rhythmical motion of the alveolar epithelial cells associated with breathing--a factor entirely ignored in current in vitro studies with static cell culture systems, and may trigger subsequent cell response. To test this idea, as an alternative approach to inhalation or instillation animal experimentation, we propose to employ an in vitro dynamic cell culture model to study particle-induced cell injury. We plan to rhythmically stretch monolayers of the human aveolar epithelial cell line A549 employing a cell stretcher device, with physiologically relevant tidal breathing conditions, and simultaneously expose the cells to various particulates, such as (fibrous and non-fibrous) asbestos, glass, polyestyrene, and latex particles. The cells' responses to particle exposure with or without rhythmic stretching will be compared by measuring important "readouts" relevant to pathogenesis, such as proinflammatory cytokine production (e.g., IL-8). The role of receptor-mediated interaction between protein-coated particles and rhythmically moving cell surface receptors will also be assessed. The results of this study would help us to understand how physical insults exerted on the expanding and contracting alveolar epithelial cell surface lead to lung injury.