Nanosized TiO2 is internalized by dorsal root ganglion cells and causes damage via apoptosis.
Titanium dioxide (TiO2) is widely used as ingredient in several products in the nanoform. TiO2-nanoparticles (NPs) are also currently studied for different medical applications. A large debate exists on possible adverse health effects related to their exposure. While there is some evidence of TiO2-NP central nervous system toxicity, their effects on peripheral neurons have been poorly explored. In this study we investigated the effects of TiO2-NPs on dorsal root ganglion (DRG) sensory neurons and satellite glial cells that may be reached by nanoparticles from the bloodstream. We found that TiO2-NPs are internalized in DRG cells and induce apoptosis in a dose dependent manner in both types of cells, ROS production and changes in expression of proinflammatory cytokine IL-1β. Furthermore, we found that the axonal retrograde transport is altered in neurons upon exposure to TiO2-NPs. Overall, the results indicate a potential neurotoxic effect of TiO2-NPs on DRG cells.


BACKGROUND
Exposure to titanium dioxide nanoparticles is increasing in medical practice. Little is known about their potential toxic effects on the peripheral nervous system. The authors studied this aspect and showed that titanium nanoparticles might potentially cause toxicity over long term.
Department of Pharmaceutical Sciences, University of Piemonte Orientale "A. Avogadro", Novara, Italy.
Jessica
J
Erriquez
Department of Chemistry, Interdepartmental Center for Nanostructured Interfaces and Surfaces (NIS), University of Torino, Italy.
Vera
V
Bolis
Department of Pharmaceutical Sciences, University of Piemonte Orientale "A. Avogadro", Novara, Italy.
Silvia
S
Morel
Department of Chemistry, Interdepartmental Center for Nanostructured Interfaces and Surfaces (NIS), University of Torino, Italy; "G. Scansetti" Interdepartmental Centre for Studies on Asbestos and other Toxic Particulates, University of Torino, Italy.
Ivana
I
Fenoglio
Department of Chemistry, Interdepartmental Center for Nanostructured Interfaces and Surfaces (NIS), University of Torino, Italy; "G. Scansetti" Interdepartmental Centre for Studies on Asbestos and other Toxic Particulates, University of Torino, Italy.
Bice
B
Fubini
Department of Chemistry, Interdepartmental Center for Nanostructured Interfaces and Surfaces (NIS), University of Torino, Italy.
Pierluigi
P
Quagliotto
Department of Pharmaceutical Sciences, University of Piemonte Orientale "A. Avogadro", Novara, Italy. Electronic address: carla.distasi@pharm.unipmn.it.
Carla
C
Distasi
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D002642:Chick Embryo; D005727:Ganglia, Spinal / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D053583:Interleukin-1beta / Q000378:metabolism; D053768:Metal Nanoparticles; D017382:Reactive Oxygen Species / Q000378:metabolism; D014025:Titanium / Q000378:metabolism* / Q000494:pharmacology
D053583:Interleukin-1beta; D017382:Reactive Oxygen Species; C009495:titanium dioxide; D014025:Titanium
Apoptosis; Axonal transport; Dorsal root ganglion; IL-1β; ROS; Titanium dioxide nanoparticles