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TiO 2 nanoparticles cause mitochondrial dysfunction, activate inflammatory responses, and attenuate phagocytosis in macrophages: A proteomic and metabolomic insight.
- Source :
-
Redox biology [Redox Biol] 2018 May; Vol. 15, pp. 266-276. Date of Electronic Publication: 2017 Dec 28. - Publication Year :
- 2018
-
Abstract
- Titanium dioxide nanoparticles (TiO <subscript>2</subscript> NPs) are widely used in food and cosmetics but the health impact of human exposure remains poorly defined. Emerging evidence suggests that TiO <subscript>2</subscript> NPs may elicit immune responses by acting on macrophages. Our proteomic study showed that treatment of macrophages with TiO <subscript>2</subscript> NPs led to significant re-organization of cell membrane and activation of inflammation. These observations were further corroborated with transmission electron microscopy (TEM) experiments, which demonstrated that TiO <subscript>2</subscript> NPs were trapped inside of multi-vesicular bodies (MVB) through endocytotic pathways. TiO <subscript>2</subscript> NP caused significant mitochondrial dysfunction by increasing levels of mitochondrial reactive oxygen species (ROS), decreasing ATP generation, and decreasing metabolic flux in tricarboxylic acid (TCA) cycle from <superscript>13</superscript> C-labelled glutamine using GC-MS-based metabolic flux analysis. Further lipidomic analysis showed that TiO <subscript>2</subscript> NPs significantly decreased levels of cardiolipins, an important class of mitochondrial phospholipids for maintaining proper function of electron transport chains. Furthermore, TiO <subscript>2</subscript> NP exposure activates inflammatory responses by increasing mRNA levels of TNF-α, iNOS, and COX-2. Consistently, our targeted metabolomic analysis showed significantly increased production of COX-2 metabolites including PGD <subscript>2</subscript> , PGE <subscript>2</subscript> , and 15d-PGJ <subscript>2</subscript> . In addition, TiO <subscript>2</subscript> NP also caused significant attenuation of phagocytotic function of macrophages. In summary, our studies utilizing multiple powerful omic techniques suggest that human exposure of TiO <subscript>2</subscript> NPs may have profound impact on macrophage function through activating inflammatory responses and causing mitochondrial dysfunction without physical presence in mitochondria.<br /> (Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.)
- Subjects :
- Animals
Cell Membrane drug effects
Cell Membrane genetics
Cyclooxygenase 2 genetics
Gene Expression Regulation drug effects
Humans
Inflammation chemically induced
Macrophages drug effects
Macrophages pathology
Metabolomics
Mice
Mitochondria pathology
Nanoparticles chemistry
Nitric Oxide Synthase Type II genetics
Phagocytosis drug effects
RAW 264.7 Cells
Reactive Oxygen Species metabolism
Titanium administration & dosage
Titanium chemistry
Tumor Necrosis Factor-alpha genetics
Inflammation genetics
Mitochondria drug effects
Nanoparticles administration & dosage
Proteomics
Subjects
Details
- Language :
- English
- ISSN :
- 2213-2317
- Volume :
- 15
- Database :
- MEDLINE
- Journal :
- Redox biology
- Publication Type :
- Academic Journal
- Accession number :
- 29294438
- Full Text :
- https://doi.org/10.1016/j.redox.2017.12.011