ABSTRACT
Objective To We Used high-dose paraquat to induce apoptosis of A549 cells,and observed the expression of E-cadherin,α-SMA,caspase-8,caspase-3 and caspase-9.Then explored the possible mechanisms of apoptosis.Methods A549 cells were treated with various concentrations of PQ (0.1-1.0 mmol/L) for 24 and 48 hours,then observe the cell morphology and measured cell survival rate respectively determined by MTT method.A549 cells were treated with various concentrations of PQ (0.1,0.2,0.3 mmol/L) for 24 hours.The expressions of the mRNAs for α-SMA、E-cadherin,caspase-8,caspase-3 and caspase-9 were analysed by quantitative real-time PCR.Exposed to various concentrations of PQ (0.1,0.2,0.3mmol/L) for 24 hours,we analysed the protein expressions of α-SMA、E-cadherin、caspase-8、caspase-3 and caspase-9 by Western blot analysis.Results Treated with various concentrations of PQ (0.1-1.0mmol/L) for 24 hours,the A549 cells survival rate significantly reduced by MTT method.For 48 hours,the survival rate was lower.So,in subsequent experiments,we used 0.1,0.2 and 0.3 mmol/L concentration of paraquat to A549 cells,trained for 24 hours.After high-dose (0.1,0.2 and 0.3 mmol/L) exposure to PQ,a decrease in E-cadherin was observed while a decrease in α-SMA was also detected of the mRNAs.While the expressions of the mRNAs for caspase-8、caspase-3 and caspase-9 wereincrease.The protein expressions of α-SMA and E-cadherin were decrease with the increase of concen trations by Western blot analysis,and the levels of caspase-8、caspase-3 and caspase-9 were increase.Conclusions After high-dose short-time exposure to PQ,the survival rate of A549 cells is decreased obviously,cell morphology changed significantly,and the expressions of α-SMA and E-cadherin were decrease.But the expressions of caspase-8、caspase-3 and caspase-9 were increase.