ABSTRACT
AIM:To investigate the effect of SET7/9 (SET domain containing 7/9) -mediated endoplasmic reticulum stress (ERS) on protein kinase R-like endoplasmic reticulum kinase (PERK) signaling pathway, and to explore the mechanisms of arsenic-induced hepatocyte apoptosis.METHODS:Human liver LO2 cells were divided into control group, arsenic poisoning model group, negative transfection group and SET7/9 siRNA transfection group.The apoptosis of the LO2 cells in each group was analyzed by flow cytometry.The protein levels of SET7/9, glucose-regulated protein 78 (GRP78) , PERK and p-PERK in the LO2 cells of each group were observed by Western blot.RESULTS:Inhibition of SET7/9 expression reduced the apoptotic rate of arsenic-induced LO2 cells.Arsenic exposure increased the expression of SET7/9 in the LO2 cells.Arsenic exposure increased the protein levels of GRP78 and p-PERK in the LO2 cells, but decreased the protein levels of GRP78 and p-PERK after transfection with SET7/9 siRNA (P<0.05).CONCLUSION:Arsenic exposure induces hepatocyte apoptosis by increasing SET7/9 to activate ERS by PERK signaling pathway.
ABSTRACT
Objective To silence human gene Set7/9 and screen out stable transfection cell line in hepatocellular carcinoma cell line HepG2 so as to investigate the impact of down-regulation of Set7/9 in cell line HepG2 and provide experimental foundation for studies on the effect of set7/9 in HepG2.Methods The target oligo was designed and synthesized;shRNA interference vector and the control vector were constructed and transfected into HepG2 cells;the stable transfection cells were screened out.Then Real-time PCR and Western blot were performed to detect the silence of Set7/9 according to both gene expression and protein expression level. Results The shRNA interference vector was constructed and transfected into HepG2 cells successfully.Compared with that in the negative control group,the expression of Set7/9 was dramatically downregulated (P < 0.05 ). Meanwhile,the expression of related protein Sirt1 and Suv39h1 was upregulated 8.4 folds and 1.1 fold, respectively.Conclusion Downregulation of Set7/9 expression can upregulate Sirt1 and Suv39h1,suggesting that Set7/9 may affect the activity of HepG2 cell lines.