title: A mechanism for nano-titanium dioxide-induced cytotoxicity in HaCaT cells under UVA irradiation.
abstract: Nano-TiO2 has been reported to be an efficient photocatalyst, which is able to produce reactive oxygen species (ROS) under UVA irradiation. In this study, we investigated the effects of nano-TiO2 on the cytotoxicity, induction of apoptosis, and the putative pathways of its actions in HaCaT cells. We show that nano-TiO2 is a potent inducer of apoptosis and that it transduces the apoptotic signal via ROS generation, thereby inducing mitochondrial permeability transition (MPT) and activating Caspase-3 from HaCaT cells. ROS production, mitochondrial alteration, and subsequent apoptotic cell death in nano-TiO2-treated cells were blocked by the MPT pore-blocker cyclosporin A. Taken together, our data indicate that nano-TiO2 induces the ROS-mediated MPT and resultant Caspase-3 activation.
authors.affiliation: a School Hospital , Huazhong University of Science and Technology , Wuhan , China.
authors.forename: Chengbin
authors.initials: C
authors.lastname: Xue
authors.forename: Wen
authors.initials: W
authors.lastname: Luo
authors.forename: Xiang Liang
authors.initials: XL
authors.lastname: Yang
mesh_terms: D017209:Apoptosis / Q000187:drug effects / Q000528:radiation effects; D053471:Caspases, Initiator / Q000096:biosynthesis / Q000235:genetics; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects* / Q000528:radiation effects; D006801:Humans; D015603:Keratinocytes / Q000187:drug effects / Q000528:radiation effects; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects* / Q000528:radiation effects; D017382:Reactive Oxygen Species / Q000378:metabolism* / Q000528:radiation effects; D014025:Titanium / Q000008:administration & dosage* / Q000737:chemistry; D014466:Ultraviolet Rays
chemical_list: D017382:Reactive Oxygen Species; C009495:titanium dioxide; D014025:Titanium; C093516:CASP4 protein, human; D053471:Caspases, Initiator
keywords: UVA irradiation; human keratinocyte (HaCaT) cells; mitochondrial permeability transition pore; nano-titanium dioxide; reactive oxygen species