title: [Role of calcium dyshomeostasis in 1-methyl-4-phenylpyridinium ion-induced apoptosis of human neuroblastoma SH-SY5Y cells].
abstract: OBJECTIVE
  To investigate the role of calcium dyshomeostasis in 1-methyl-4-phenylpyridinium ion (MPP⁺)-induced apoptosis of human neuroblastoma SH-SY5Y cells.
  
  
  METHODS
  The viability of SH-SY5Y cells exposed to varying concentrations of MPP⁺ was assessed using MTT colorimetric assay, and MPP⁺-induced cell apoptosis was detected with hoechst 33342 staining and Annexin V+PI assay. Western blotting and rhodamine 123 staining were employed to examine the changes in cellular poly(ADP-ribose) polymerase (PARP) protein expression and mitochondrial membrane potential in response to MPP⁺ exposure. The effects of ruthenium red and/or MPP⁺ on calcium concentration in the cytoplasm, mitochondria and endoplasmic reticulum were evaluated using confocal microscopy.
  
  
  RESULTS
  MPP⁺ induced apoptosis and caused reduced cell viability and mitochondrial membrane potential in SH-SY5Y cells. The cells exposed to MPP⁺ showed a lowered calcium concentration in the cytoplasm and endoplasmic reticulum and an increased mitochondrial Ca²⁺ uptake. Ruthenium red rescued MPP⁺-induced apoptosis and mitochondrial membrane potential reduction, reduced PARP cleavage, and inhibited the increase of mitochondrial matrix free Ca²⁺ in the cells exposed to MPP⁺.
  
  
  CONCLUSIONS
  Mitochondrial calcium overload plays an important role in MPP⁺-induced apoptosis of SH-SY5Y cells, which is closely associated with dysregulation of intracellular Ca²⁺ homeostasis.
authors: Department of Occupational Health and Medicine, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou 510515, China. xuleizh@126.com
authors: Lei
authors: L
authors: Xu
authors: Wenjun
authors: W
authors: Li
authors: Danmiao
authors: D
authors: Lin
authors: Hongmei
authors: H
authors: Zhang
authors: Fei
authors: F
authors: Zou
mesh_terms: D015655:1-Methyl-4-phenylpyridinium / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D002118:Calcium / Q000378:metabolism*; D045744:Cell Line, Tumor; D002470:Cell Survival; D003593:Cytoplasm / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism; D006706:Homeostasis; D006801:Humans; D053078:Membrane Potential, Mitochondrial; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism
chemical_list: D011065:Poly(ADP-ribose) Polymerases; D015655:1-Methyl-4-phenylpyridinium; D002118:Calcium