title: Cytotoxic effect of zinc oxide nanoparticles on murine photoreceptor cells via potassium channel block and Na+/K+-ATPase inhibition.
abstract: OBJECTIVE
  Zinc oxide (ZnO) nanoparticles can exhibit toxicity towards organisms and oxidative stress is often hypothesized to be one of the most important factors. Nevertheless, the detailed mechanism of toxicity-induced by ZnO nanoparticles has not been completely addressed. The present study aimed to investigate the toxic effects of ZnO nanoparticles on the expression and activity of Na+/K+-ATPase and on potassium channel block.
  
  
  METHODS
  In the present study, we explored the cytotoxic effect of ZnO nanoparticles on murine photoreceptor cells using lactate dehydrogenase (LDH) release assay, reactive oxygen species (ROS) determination, mitochondrial membrane potential (Δφm) measurement, delayed rectifier potassium current recordings and Na+/K+-ATPase expression and activity monitoring.
  
  
  RESULTS
  The results indicated that ZnO nanoparticles could increase the LDH release in medium, aggravate the ROS level within cells, collapse the Δφm, block the delayed rectifier potassium current, and attenuate the expressions of Na+/K+-ATPase at both mRNA and protein levels and its activity, and thus exert cytotoxic effects on murine photoreceptor cells, finally damaging target cells.
  
  
  CONCLUSIONS
  Our findings will facilitate the understanding of the mechanism involved in ZnO nanoparticle-induced cytotoxicity in murine photoreceptor cells via potassium channel block and Na+/K+-ATPase inhibition.
authors.affiliation: Department of Ophthalmology, The Affiliated Hospital of Qingdao University, Qingdao, Shandong Province, China.|Department of Ophthalmology, The First People's Hospital of Jining, Jining, Shandong Province, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Chen
authors.affiliation: Department of Ophthalmology, The First People's Hospital of Jining, Jining, Shandong Province, China.
authors.forename: Wenjuan
authors.initials: W
authors.lastname: Bu
authors.affiliation: Jiangsu Provincial Key Laboratory for Interventional Medical Devices, Huaiyin Institute of Technology, Huaian, Jiangsu Province, China.
authors.forename: Hongyan
authors.initials: H
authors.lastname: Ding
authors.affiliation: Department of Integration of Chinese and Western Medicine, The Affiliated Yantai Yuhuangding Hospital of Qingdao University, Yantai, Shandong Province, China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Li
authors.affiliation: Department of Ophthalmology, The Affiliated Hospital of Qingdao University, Qingdao, Shandong Province, China.
authors.forename: Dabo
authors.initials: D
authors.lastname: Wang
authors.affiliation: Eye Institute of Shandong University of Traditional Chinese Medicine, Jinan, Shandong Province, China.
authors.forename: Hongsheng
authors.initials: H
authors.lastname: Bi
authors.affiliation: Eye Institute of Shandong University of Traditional Chinese Medicine, Jinan, Shandong Province, China.
authors.forename: Dadong
authors.identifier: http://orcid.org/0000-0002-1712-0055
authors.initials: D
authors.lastname: Guo
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D051379:Mice; D053758:Nanoparticles / Q000737:chemistry*; D010786:Photoreceptor Cells / Q000187:drug effects*; D026902:Potassium Channel Blockers / Q000737:chemistry / Q000494:pharmacology*; D015221:Potassium Channels / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D013329:Structure-Activity Relationship; D015034:Zinc Oxide / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D004791:Enzyme Inhibitors; D026902:Potassium Channel Blockers; D015221:Potassium Channels; D017382:Reactive Oxygen Species; D000254:Sodium-Potassium-Exchanging ATPase; D015034:Zinc Oxide
keywords: Na+/K+-ATPase; delayed rectifier potassium current; murine photoreceptor cell; reactive oxygen species; zinc oxide nanoparticle