Effects of Exendin-4 on expressions of lipid metabolism related genes in HepG2 cells with insulin resistance / 吉林大学学报(医学版)

ABSTRACT

Objective: To investigate the effects of Exendin-4 (Ex-4) on the expressions of lipid metabolism related genes in the human liver cancer HepG2 cells with insulin resistance (IR), and to elucidate the effect of Ex-4 in improvement of IR. Methods: The HepG2 cells in logarithmic growth phase were induced into IR model with high concentration of insulin, then divided into control group (HepG2 cells), IR group (HepG2 cells were treated with insulin, HepG2-IR cells), and Ex-4 group (HepG2-IR cells were treated with Ex-4). Glucose oxidase (GOD-POD) kit was used to detect the consumption of glucose. The cell morphology and intracellular lipid drip formation were observed by Oil red O staining. The triglyceride (TG) level in cells was detected by kit; qRT-PCR was used to detect the mRNA expression levels of acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), sterol regulatory element-binding protein-1c (SREBP-lc) and apolipoprotein B100 (apoBlOO). Results: Compared with control group (HepG2 cells), the glucose consumption in the HepG2-IR cells in IR group was significantly decreased (P<0. 01). Compared with IR group, the glucose consumption in the HepG2-IR cells in Ex-4 group was increased (P<0. 05). The Oil O red staining results showed that compared with control group, the fat percentage in the HepG2-IR cells in IR group was increased (P<0. 05); compared with IR group, the fat percentage in Ex-4 group was decreased (P< 0.05). Compared with control group, the level of TG in the cells in IR group was significantly increased (P< 0. 01); compared with IR group, the level of TG in the cells in Ex-4 group was significantly decreased (P<0. 05). The qT-PCR results showed that compared with control group, the expression levels of ACC FAS and SREBP-lc mRNA in the cells in IR group were increased (P<0. 01), and the expression level of apoBlOO mRNA was decreased (P<0. 05); compared with IR group, the expression levels of ACC, FAS and SREBP-lc mRNA in the cells in Ex-4 group were decreased (P<0. 05), and the expression level of apoBlOO mRNA was increased (P< 0.01). Conclusion: Ex-4 can regulate the expressions of lipid metabolism related genes in the HepG2 cells and improve IR.