Study on the apoptosis of human vascular smooth muscle cells induced by proteasome inhibitor MG132 and its mechanisms

AIM: To study the effect of proteasome inhibitor MG132 on the expression of caspase 3 and the apoptosis in cultured human umbilical vascular smooth muscle cells.METHODS: Human umbilical vascular smooth muscle cells were treated with MG132(2.5,5,10 μmol/L) for 24 hours and for 48 hours.The apoptotic cells were determined by flow cytometric analysis. The levels of Ub,E1,E2,E3,26S and caspase 3 mRNA expression were detected by reverse transcription-polymerase chain reaction(RT-PCR).The expression of caspase 3 protein was detected by immunocytochemistry.RESULTS:The results showed that the expressions of Ub,E1,E2,E3,26S genes were decreased in treatment group and the apoptosis rates were increased obviously.MG132 could up-regulate the gene/protein expression of caspase 3.CONCLUSION:The results implicate that proteasome inhibitor MG132 could dose-dependently induce human umbilical vascular smooth muscle cells apoptosis,the apoptosis of human umbilical vascular smooth muscle cells induced by MG132 probably is relates to the decreases of Ub,E1,E2,E3 and 26S expressions and the increase of caspase 3 expression.