Particles induce apical plasma membrane enlargement in epithelial lung cell line depending on particle surface area dose

Brandenberger, C; Rothen-Rutishauser, B; Blank, F; Gehr, P; Mühlfeld, C (2009). Particles induce apical plasma membrane enlargement in epithelial lung cell line depending on particle surface area dose. Respiratory research, 10(1), p. 22. London: BioMed Central 10.1186/1465-9921-10-22

1465-9921-10-22.pdf - Published Version
Available under License Creative Commons: Attribution (CC-BY).

Download (1MB) | Preview


Airborne particles entering the respiratory tract may interact with the apical plasma membrane (APM) of epithelial cells and enter them. Differences in the entering mechanisms of fine (between 0.1 μm and 2.5 μm) and ultrafine ( ≤ 0.1 μm) particles may be associated with different effects on the APM. Therefore, we studied particle-induced changes in APM surface area in relation to applied and intracellular particle size, surface and number.

Human pulmonary epithelial cells (A549 cell line) were incubated with various concentrations of different sized fluorescent polystyrene spheres without surface charge (∅ fine – 1.062 μm, ultrafine – 0.041 μm) by submersed exposure for 24 h. APM surface area of A549 cells was estimated by design-based stereology and transmission electron microscopy. Intracellular particles were visualized and quantified by confocal laser scanning microscopy.

Particle exposure induced an increase in APM surface area compared to negative control (p < 0.01) at the same surface area concentration of fine and ultrafine particles a finding not observed at low particle concentrations. Ultrafine particle entering was less pronounced than fine particle entering into epithelial cells, however, at the same particle surface area dose, the number of intracellular ultrafine particles was higher than that of fine particles. The number of intracellular particles showed a stronger increase for fine than for ultrafine particles at rising particle concentrations.

This study demonstrates a particle-induced enlargement of the APM surface area of a pulmonary epithelial cell line, depending on particle surface area dose. Particle uptake by epithelial cells does not seem to be responsible for this effect. We propose that direct interactions between particle surface area and cell membrane cause the enlargement of the APM.

Item Type:

Journal Article (Original Article)


04 Faculty of Medicine > Pre-clinic Human Medicine > Institute of Anatomy > Topographical and Clinical Anatomy
04 Faculty of Medicine > Pre-clinic Human Medicine > BioMedical Research (DBMR) > Forschungsbereich Mu50 > Forschungsgruppe Pneumologie (Erwachsene)
04 Faculty of Medicine > Department of Gastro-intestinal, Liver and Lung Disorders (DMLL) > Clinic of Pneumology

UniBE Contributor:

Brandenberger, Christina, Rothen-Rutishauser, Barbara, Blank, Fabian




BioMed Central




Factscience Import

Date Deposited:

04 Oct 2013 15:13

Last Modified:

05 Dec 2022 14:22

Publisher DOI:


PubMed ID:


Web of Science ID:




URI: (FactScience: 197350)

Actions (login required)

Edit item Edit item
Provide Feedback