Objective To study the effects of manganese chloride (MnCl2) on mitochondrial damage, oxidative stress, secretion of dopamine, and expression of PARK2 in human bone marrow neuroblastoma cells (SH-SY5Y).
Methods SH-SY5Y cells were exposed to MnCl2 (0, 100, 300, and 500 μmol/L) for 24 h. MTT assay was used to measure in hibition rate of the cells (mitochondrial damage), graphite furnace atomic absorption spectrometry for intracellular manganese concentration, water soluble tetrazolium salt (WST-1) assay for superoxide dismutase (SOD) activity, thiobarbituric acid assay for malondialdehyde (MDA) level, reverse phase high performance liquid chromatography-fluorometry for dopamine (DA) level, RT-PCR for the expression of PARK2 mRNA, and Western blot for the expression of Parkin protein, respectively.
Results The cell inhibition rates (mitochondrial damage) of the 300 and 500 μmol/L MnCl2 groups were increased compared with the control group (P < 0.01). The intracellular manganese concentration of the SH-SY5Y cells was increased in the MnCl2 groups compared with the control group (P < 0.05 or P < 0.01). Compared with the control group, decreasing SOD activities and DA levels and increasing MDA levels were observed in the 300 and 500 μmol/L MnCl2 groups (P < 0.01). At the same time, the expressions of PARK2 mRNA and Parkin protein were also decreased (P < 0.01). The results of correlation analysis revealed that the expression of PARK2 mRNA was inversely correlated with cell inhibition rate (mitochondrial damage) (r=-0.872), in tracellular manganese concentration (r=-0.880), and MDA level (r=-0.862) (all Ps < 0.01), respectively; the expression of PARK2 mRNA was positively correlated with SOD activity (r=0.879), DA level (r=0.859), and the expression of Parkin protein (r=0.809) (all Ps < 0.01), respectively.
Conclusion MnCl2 exposure could induce mitochondrial damage, oxidative stress, and decreased DA secretion and expression of PARK2 in SH-SY5Y cells.
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