The Mechanism of Metformin Improves Insulin Sensitivity in Human Adipocytes and Inhibits the Inflammatory Response through the AMPK/PTEN Pathway
LIU Zi'ang
ZHANG Jian
YIN Jianhong
TIAN Yanzhang
ZHAO Haoliang
Abstract：Objective:To evaluate the improvement of insulin resistance and inflammatory response in human mature adipocytes induced by metformin and to explore the potential mechanism through the AMP-activated protein kinase(AMPK)/phosphatase and tensin homolog(PTEN)pathway.Methods:Human preadipocytes were induced to differentiate into mature adipocytes,which was verified by oil red O staining.The differentiated human adipocytes were divided into three groups:the control group,the low-dose metformin group,and the high-dose metformin group.Then,the mature adipocytes were treated with different concentrations of metformin(0,1,and 10 mmol/L),respectively.After 24 hours of treatment,total RNA was extracted from the cells and reverse transcribed into cDNA,and the mRNA levels of AMPK,PTEN,glucose transporter 4(GLUT4),and interleukin-6(IL-6)were detected in mature adipocytes using real-time fluorescence quantitative PCR(qRT-PCR).In addition,after the differentiated adipocytes were treated with metformin for 24 hours,the cells were collected to extract total protein,and changes in protein expression levels were detected by Western Blot.Results:Oil Red O staining verified the successful differentiation of human preadipocytes into mature adipocytes.The results of qRT-PCR showed that compared with the control group,there was no statistically significant difference in the expression of AMPK mRNA between the low-dose metformin group and the high-dose metformin group(P＞0.05),while the level of PTEN mRNA was significantly decreased(P＜0.05).Compared with the control group,the expression level of GLUT4 mRNA in the high-dose metformin group was significantly increased(P＜0.001),and the level of IL-6 mRNA in mature adipocytes was down-regulated(P＜0.01).Western Blot results showed that the expression of phosphorylated AMPK(p-AMPK)protein was positively regulated by metformin,while the expression levels of PTEN protein and inflammatory factor IL-6 protein decreased,and the expression level of GLUT4 protein in adipocytes increased.This was basically consistent with the results of RT-PCR.Meanwhile,metformin intervention could reduce the expression of IL-6 mRNA.Conclusion:At the transcriptional level,metformin intervention has no regulatory effect on AMPK mRNA expression,but it can down-regulate PTEN mRNA expression in human adipocytes,thereby up-regulating GLUT4 mRNA expression.Meanwhile,metformin intervention can reduce the expression of inflammatory factor IL-6 mRNA.At the protein level,metformin intervention can activate AMPK,thereby influencing the expression of PTEN and GLUT4 proteins and improving insulin resistance.Meanwhile,chronic inflammation response in human adipocytes also reduced with the decreased level of IL-6.
Keywords：insulin resistancemetforminhuman retinal adipocytesAMP-activated protein kinasephosphatase and tensin homologinflammatory response
Publication Date：2025-12-10
Online Publishing Date：2025-12-19(First online date of this platform, not the publication date of the document)
Pages：6( 3584-3589 )