title: UVB irradiation enhances TiO2 nanoparticle-induced disruption of calcium homeostasis in human lens epithelial cells.
abstract: Currently, titanium dioxide nanoparticles (TiO2 NPs) have been widely used in various applications including cosmetics, food additives and biomedicine. However, there are few reports available using TiO2 NPs to treat ocular diseases. Posterior capsular opacification (PCO) is the most frequent complication after cataract surgery, which is induced by the proliferation and migration of lens epithelial cells. Thus, inhibiting the proliferation of lens epithelial cells will efficiently reduce the occurrence of PCO. In this study, we investigated the effects of TiO2 NPs on HLE B-3 cells with or without ultraviolet B (UVB) irradiation in vitro. We found that TiO2 NPs can inhibit HLE B-3 cell growth, cause the elevation of intracellular [Ca(2+)], produce excessive reactive oxygen species (ROS), further reduce Ca(2+)-ATPase activity and decrease the expression of plasma membrane calcium ATPase 1 (PMCA1), finally disrupt the intracellular calcium homeostasis and induce cell damage. Importantly, UVB irradiation can apparently enhance these effects on HLE B-3 cells in the presence of TiO2 NPs. Taken together, the generation of excessive ROS and the disruption of intracellular calcium homeostasis may be both involved in TiO2 nanoparticle-induced HLE B-3 cell damage under UVB irradiation.
authors: Affiliated Eye Hospital of Shandong University of Traditional Chinese Medicine, Jinan, China; The Second Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, China.
authors: Qiuxin
authors: Q
authors: Wu
authors: Dadong
authors: D
authors: Guo
authors: Yuxiang
authors: Y
authors: Du
authors: Dongmei
authors: D
authors: Liu
authors: Daoguang
authors: D
authors: Wang
authors: Hongsheng
authors: H
authors: Bi
mesh_terms: D001483:Base Sequence; D002118:Calcium / Q000378:metabolism*; D002460:Cell Line; D017931:DNA Primers; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism; D006706:Homeostasis / Q000187:drug effects*; D006801:Humans; D007908:Lens, Crystalline / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D053768:Metal Nanoparticles / Q000633:toxicity*; D046529:Microscopy, Electron, Transmission; D053499:Plasma Membrane Calcium-Transporting ATPases / Q000235:genetics / Q000378:metabolism; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics; D014025:Titanium / Q000633:toxicity*; D014466:Ultraviolet Rays
chemical_list: D017931:DNA Primers; D012333:RNA, Messenger; C009495:titanium dioxide; D014025:Titanium; D053499:Plasma Membrane Calcium-Transporting ATPases; D002118:Calcium