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Harvesting Murine Alveolar Macrophages and Evaluating Cellular Activation Induced by Polyanhydride Nanoparticles
Published on: June 8, 2012
A murine scavenger receptor MARCO recognizes polystyrene nanoparticles
Sanae Kanno1, Akiko Furuyama, Seishiro Hirano
1Environmental Nanotoxicology Section, Research Center for Environmental Risk, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, Japan. sanae@nies.go.jp
Summary
Macrophages use the MARCO receptor to bind and ingest nanoparticles, aiding in the clearance of these ultrafine particles from the lungs. This discovery is crucial for understanding nanoparticle toxicity and lung defense mechanisms.
Area of Science:
- Toxicology
- Cell Biology
- Nanotechnology
Background:
- Nanoparticles (< 100 nm) exhibit higher toxicity due to increased surface area compared to fine particles (< 2 microm).
- Alveolar macrophages are key in lung defense, utilizing scavenger receptors like MARCO (macrophage receptor with collagenous structure) to bind environmental particles.
- The role of MARCO in the cellular uptake of nanoparticles remains largely unknown.
Purpose of the Study:
- To investigate whether MARCO mediates the cellular uptake of nanoparticles.
- To determine if MARCO plays a role in the clearance of nanoparticles from the alveolar region.
Main Methods:
- Utilized fluorescent-tagged polystyrene nanoparticles (20 nm, 200 nm, 1 microm) to study cellular uptake.
- Employed COS-7 cells transfected with MARCO cDNA or an empty vector.
- Observed particle association using fluorescence microscopy and atomic force microscopy.
Main Results:
- MARCO-transfected cells demonstrated time-dependent association with all tested nanoparticle sizes (20 nm, 200 nm, 1 microm).
- Empty vector-transfected cells showed minimal particle binding after 5 hours.
- PolyG partially inhibited nanoparticle uptake by MARCO-transfected cells, suggesting MARCO's involvement.
Conclusions:
- Macrophages utilize the MARCO receptor for binding and internalizing nanoparticles, particularly the smallest ones (20 nm).
- MARCO plays a significant role in the clearance of nanoparticles that deposit in the alveolar region of the lungs.
- Findings contribute to understanding nanoparticle toxicity and the lung's defense mechanisms against ultrafine particles.
