The Role Of The AMPK-mTOR Signal Pathway In Manganese-Induced Autophagy Of PC12 Cells

Objective:Autophagy is the main mechanism for degradation of long-lived protein and regulation of cell metabolism in eukaryotic cells,and it is under the control of multiple signal pathway.This study establishes the modal of manganese toxic Parkinsonism in vitro by using manganese in PC12 cells.It aims to explore the role of the AMPK-mTOR signal pathway in manganese-induced autophagy of PC12 cells,and it may provide thoughts for the pathogenesis of manganese toxic Parkinson syndrome and drug research.Methods:We chose suitable concentration and time for establishing the modal of manganese toxic Parkinson syndrome on the basis of the impact on the survival rate of PC12 cells treated with manganese in disparate concentrations and times.Then we gave Compound C to the cells for test.We used the cell counting kit-8 to measure the cells survival rate.Meanwhile,transmission electron microscope was used to observe ultrastructure of PC12 cells which were treated with manganese.Moreover,we detected the amount of target protein,such as LC3,p-AMPK,p-mTOR,p-p70S6 K and p-4E-BP1 by Western Blot.Results:1.PC12 cells were treated with manganese in variousconcentrations at 24 h,48h and 72 h,then we detected the cells survival rate by CCK-8.It shown that the cells survival rates of different manganese concentrations and different time points were significant difference from the control(P?0.01).2.Every groups were treated at 24 h.The cells survival rate of control group was(100±0)%,and the cells survival rates of drug groups were decreasing(P ? 0.01).Cells survival rate of group manganese combined with Compound C was increasing in contrast with manganese group.3.As the concentration of manganese and time increasing,the protein expression of LC3-?/LC3-?increased.4.It was observed that the autophagosomes and autolysosomes were increased in PC12 cells treated with manganese under the transmission electron microscope.5.The protein expressions of p-AMPK and LC3 were increased more in manganese group than control group(P?0.01),and the protein expressions of p-mTOR,p-p70S6 K and p-4E-BP1 were opposite(P?0.01).These protein expressions in group manganese combined with Compound C were fell in between manganese group and control group(P?0.05).Conclusions:1.Manganese can induced autophagy in PC12 cells and cause the inhibition of cell proliferation with the concentration and time increasing.2.Compound C can down-regulate activation of autophagy induced with manganese in PC12 cells.3.Manganese may induce autophagy in PC12 cells and cause the inhibition of cell proliferation via AMPK-mTOR signal pathway.4.The AMPK-mTOR signal pathway may take part in the nosogenesis of manganese toxic Parkinson syndrome.