Pathogenic Role Of Phospholipase C Epsilon 1 In Streptozotocin-induced INS-1 Cell Injury

Objective: To explore the pathogenic role of phospholipase C epsilon-1(PLCE1)in streptozotocin(STZ)-induced INS-1 cell injury.Methods: The cell counting kit-8(CCK-8)was used to detect cell viability to determine the appropriate concentration and duration of STZ.INS-1 cells,PLCE1 knockdown or overexpression and negative control INS-1 cells were treated with STZ(350 μM)or sodium citrate buffer for 48 h.The expression levels of PLCE1,glucose transporters 2(GLUT2),poly ADP-ribose polymerase-1(PARP-1)and nuclear factor κB p65(NF-κB p65)were examined by western blotting and reverse transcription-quantitative PCR(RT-q PCR).2,7-dichlorofuorescin diacetate(DCFH-DA)was used to evaluate the content of intracellular reactive oxygen species(ROS).The m RNA expression levels of Ins1(insulin transcript 1)and Ins2(insulin transcript 2),insulin content of cell culture supernatants and the cell viability were used as indicators to evaluate the severity of INS-1 cell injury.Results: No significant difference was found in INS-1 cells treated with or without sodium citrate buffer(P>0.05).PLCE1,PARP-1 and NF-κB p65 protein and m RNA expressions and the content of ROS were significantly higher while GLUT2 protein and m RNA expressions,Ins1 and Ins2 m RNA expressions,insulin content and the cell viability were significantly lower in INS-1 cells treated with STZ than in those treated with sodium citrate buffer(P<0.05).Downregulating or upregulating PLCE1 had no effect on the decrease of GLUT2 protein and m RNA expression induced by STZ.But downregulating PLCE1 significantly inhibited STZ-induced upregulation of PARP-1,NF-κB p65 and ROS production to alleviated INS-1 cell injury(P<0.05).Whereas upregulating PLCE1 caused the opposite changes(P<0.05).Conclusion: Knockdown of PLCE1 can alleviate STZ-induced INS-1 cell injury by downregulating PARP-1 and NF-κB p65 and reducing ROS production instead of GLUT2.On the contrary,overexpression of PLCE1 can aggravate cell injury by further upregulating PARP-1,NF-κB p65 and increasing ROS production.