title: Effects of exogenous zinc on the cellular zinc distribution and cell cycle of A549 cells.
abstract: As the second most abundant transition metal in humans, zinc plays essential roles in normal cellular biological functions, including metabolism, signalling, proliferation, gene expression and apoptosis. We use ZnSO(4) as a stressor in this study to investigate for the first time the effects of exogenous Zn(2+) on both the cellular distribution of zinc and zinc-related proteins and the cell cycle of human lung adenocarcinoma (A549) cells. The cellular distribution of zinc and soluble proteins was determined in the whole cell as well as in the cytoplasmic and nuclear fractions. Exogenous zinc in the tested exposure range (0-100 µM) resulted in an altered cellular distribution of both zinc and the soluble proteins, together with total glutathione (GSx), the ratio of glutathione (GSH) to glutathione disulfide (GSSG) and non-protein sulphydryl (NPSH). Surprisingly, a turning point was observed in the re-distribution trend at a concentration of approximately 50 µM ZnSO(4). It is concluded that there exists a regulatory system in A549 cells that maintains the cellular zinc content stable in the presence of a certain range of extracellular zinc concentration. In addition, an MTT assay and flow cytometric analysis showed that the ZnSO(4) treatment led to a bi-phasic variation in viability and a slight fluctuation in the apoptosis of A549 cells. Our results will help to further elucidate zinc-related cell biology and biochemistry.
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry & Chemical Engineering and Center of Materials Analysis, Nanjing University, 22 Hankou Road, Nanjing 210093, China.
authors.forename: Na
authors.initials: N
authors.lastname: Yuan
authors.forename: Yan-Hong
authors.initials: YH
authors.lastname: Wang
authors.forename: Ke-Jin
authors.initials: KJ
authors.lastname: Li
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhao
authors.forename: Xin
authors.initials: X
authors.lastname: Hu
authors.forename: Li
authors.initials: L
authors.lastname: Mao
authors.forename: Wen-Jie
authors.initials: WJ
authors.lastname: Zhao
authors.forename: Hong-Zhen
authors.initials: HZ
authors.lastname: Lian
authors.forename: Wei-Juan
authors.initials: WJ
authors.lastname: Zheng
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D001692:Biological Transport / Q000187:drug effects; D002453:Cell Cycle / Q000187:drug effects*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D005110:Extracellular Space / Q000187:drug effects / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D005978:Glutathione / Q000378:metabolism; D019803:Glutathione Disulfide / Q000378:metabolism; D006801:Humans; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism; D012995:Solubility; D019287:Zinc Sulfate / Q000378:metabolism* / Q000494:pharmacology*
chemical_list: D019287:Zinc Sulfate; D005978:Glutathione; D019803:Glutathione Disulfide