Autophagy induced by silica nanoparticles protects RAW264.7 macrophages from cell death

Clarissa Marquardt; Susanne Fritsch-Decker; Marco Al-Rawi; Silvia Diabaté; Carsten Weiss

doi:10.1016/j.tox.2017.01.019

Autophagy induced by silica nanoparticles protects RAW264.7 macrophages from cell death

Toxicology. 2017 Mar 15:379:40-47. doi: 10.1016/j.tox.2017.01.019. Epub 2017 Feb 1.

Authors

Clarissa Marquardt¹, Susanne Fritsch-Decker², Marco Al-Rawi³, Silvia Diabaté⁴, Carsten Weiss⁵

Affiliations

¹ Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Campus North, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany. Electronic address: clarissa.marquardt@kit.edu.
² Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Campus North, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany. Electronic address: susanne.fritsch-decker@kit.edu.
³ Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Campus North, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany. Electronic address: marco.al-rawi@web.de.
⁴ Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Campus North, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany. Electronic address: silvia.diabate@kit.edu.
⁵ Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Campus North, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany. Electronic address: carsten.weiss@kit.edu.

PMID: 28161448
DOI: 10.1016/j.tox.2017.01.019

Abstract

Although the technological and economic benefits of engineered nanomaterials are obvious, concerns have been raised about adverse effects if such material is inhaled, ingested, applied to the skin or even released into the environment. Here we studied the cytotoxic effects of the most abundant nanomaterial, silica nanoparticles (SiO₂-NPs), in murine RAW264.7 macrophages. SiO₂-NPs dose-dependently induce membrane leakage and cell death without obvious involvement of reactive oxygen species. Interestingly, at low concentrations SiO₂-NPs trigger autophagy, evidenced by morphological and biochemical hallmarks such as autophagolysosomes or increased levels of LC3-II, which serves to protect cells from cytotoxicity. Hence SiO₂-NPs initiate an adaptive stress response which dependent on dose serve to balance survival and death and ultimately dictates the cellular fate.

Keywords: Amorphous silica; Autophagy; Cell death; Macrophages; Nanoparticles.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Autophagy / drug effects
Autophagy / physiology*
Cell Death / drug effects
Cells, Cultured
Macrophages / drug effects*
Mice
Nanoparticles / toxicity*
Reactive Oxygen Species / metabolism
Silicon Dioxide / toxicity*

Substances

Reactive Oxygen Species
Silicon Dioxide