The Effect Of Iron On Cell Proliferation And Tau Phosphorylation In SH-SY5Y Cell

Objective:To explore the toxic effects of iron on the proliferation and tau phosphorylation in SH-SY5Y cell and provide the data for elucidating the pathogenesis of neurodegenerative disease ,which may undergo the pathological change of iron deposist and iron induced oxidative stress.Methods:The effect of a wide range of concentrations of FeCl₃ on the proliferation of neuroblastoma cells was measured by the MTT method and cytometry .Morphological changes of the cells were observed under the inverted phase contrast microscope and electronmicroscope.Cell apoptosis was determined by the flow cytometry assay in PI stain. Immumofluorescence method was applied to observe the expression of tau protein and fluorescence intensity(FI) was measured by laser scanning confocal microscope.Results:Extracellular iron( FeCl₃ )within the concentration range (0.2～2mmol/L) could induce the decrease of mean value of OD and survival rate .The inhibition effect was dose and time dependent.Iron at low concentration(0.2-0.8 mmol/L) did not result in apoptosis and necrosis by the flow cytometry assay and electronmicroscope,but could induce increase of tau-1 fluorescence intensity.Iron at high concentration(1～2mmol/L) could result in necrosis and decrease of tau-1 fluorescence intensity.Conclusions:Iron at a certain concentration may inhibit the proliferation in a dose and time dependent way and induce increased expression of dephosphorylated tau protein in the neuroblastoma cells.