title: Molecular mechanism of hippocampal apoptosis of mice following exposure to titanium dioxide nanoparticles.
abstract: Previous studies demonstrate that the exposure to titanium dioxide nanoparticles (TiO(2) NPs) damages the central nervous system of mice; however, very little is known about the effects of TiO(2) NPs on hippocampal apoptosis or its molecular mechanism. The present study investigated the molecular mechanism associated with hippocampal apoptosis in mice induced by intragastric administration of TiO(2) NPs for consecutive 60 days. Our findings indicate that TiO(2) NPs accumulate in the mouse hippocampus, and this accumulation, in turn, led to hippocampal apoptosis and impairment in spatial recognition memory in mice. In addition, TiO(2) NPs significantly activated caspase-3 and -9, inhibited Bcl-2, and promoted the levels of Bax and cytochrome c. Furthermore, TiO(2) NPs induced accumulation of reactive oxygen species in the mouse hippocampus. These findings suggest that TiO(2) NP-induced apoptosis in the mouse hippocampus may result from an intrinsic pathway, and workers and consumers should take great caution when handling nanomaterials.
authors.affiliation: Medical College, Soochow University, Suzhou, China.
authors.forename: Renping
authors.initials: R
authors.lastname: Hu
authors.forename: Lei
authors.initials: L
authors.lastname: Zheng
authors.forename: Ting
authors.initials: T
authors.lastname: Zhang
authors.forename: Guodong
authors.initials: G
authors.lastname: Gao
authors.forename: Yaling
authors.initials: Y
authors.lastname: Cui
authors.forename: Zhe
authors.initials: Z
authors.lastname: Cheng
authors.forename: Jie
authors.initials: J
authors.lastname: Cheng
authors.forename: Mengmeng
authors.initials: M
authors.lastname: Hong
authors.forename: Meng
authors.initials: M
authors.lastname: Tang
authors.forename: Fashui
authors.initials: F
authors.lastname: Hong
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects*; D001483:Base Sequence; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism; D017931:DNA Primers; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects* / Q000648:ultrastructure; D015227:Lipid Peroxidation; D008297:Male; D053768:Metal Nanoparticles; D051379:Mice; D008813:Mice, Inbred ICR; D016133:Polymerase Chain Reaction; D017382:Reactive Oxygen Species / Q000378:metabolism; D014025:Titanium / Q000633:toxicity*
chemical_list: D000975:Antioxidants; D061945:Caspase Inhibitors; D017931:DNA Primers; D017382:Reactive Oxygen Species; C009495:titanium dioxide; D014025:Titanium; D020169:Caspases