Abstract: FR-PO608

Inhibition of High Glucose Induced Senescence of Human Glomerular Mesangial Cells by Metformin Up-Regulating Autophagy Level

Session Information

Category: Diabetes

  • 501 Diabetes Mellitus and Obesity: Basic - Experimental

Authors

  • Wang, Xiuying, The First Hospital of China Medical University, Shenyang, China
  • Wang, Lining, Department of Nephrology, First Affiliated Hospital of China Medical University, Shenyang, P. R. China, Shenyang, China
  • Yang, Shuang, The First Hospital of China Medical University, Shenyang, China
  • Sun, Dan, The First Hospital of China Medical University, Shenyang, China
Background

Autophagy has been found to be closely related to aging and human disease.However, the role of autophagy in the process of human mesangial cell senescence and its mechanism is unclear. In recent years the study found that metformin can activate the AMPK signaling pathway, inhibition of mTOR pathway and affect autophagy. Here we try to investigate the effects of metformin on autophagy and human glomerular mesangial cells senescence induced by high glucose.

Methods

Human glomerular mesangial cells (HGMCs) were cultured in vitro ,and exposed to high glucose (30.0 mmol / L glucose) for 12,24,48 and 72 h and stimulated by high glucose with 10mmol/L metformin for 72 h. Normal control group(5.5mmol/L glucose)and hypertonic group(5.5 mmol/L glucose+24.5 mmol/L mannitol) were set up.The best stimulating concentration of metformin was filtered by Cell Counting Kit(CCK-8/WST-8).The cell senescence was evaluated byβ-galactosidase(SA-β-gal)staining.The activation of AMPK/mTOR pathway ,aging related proteins p53,p21 and autophagy marker proteins LC3,p62/SQSTMI were determined by Western blotting.Autophagic flux was detected by (mRFP-GFP-LC3 )adenovirus observed using confocal microscopy.

Results

Compared with the normal control group, the cells exposed to high glucose for 12,24 and 48h showed up-regulated p53 and mTOR expression(P<0.05),the cells exposed to high glucose for 24 and 48h showed up-regulated p21 and p-mTOR expression(P<0.05),the cells exposed to high glucose for 24,48 and 72h showed down-regulated p-AMPK expression(P<0.05), up-regulated p62/SQSTM1 expression and increased percentage of SA-β-gal positive cells(P<0.05).The cells exposed to high glucose for 72h showed down-regulated LC3 expression and decreased autophagic flux level(P<0.05).Compared with those in high glucose group,The autophagic flux level and the expression of p-AMPK, LC3were increased dramatically in high glucose with metformin group( P<0.05),while the protein expressions of p62,p53,p21,mTOR and p-mTOR decreased (P<0.05),and SA -β-gal positive cells decreased(P<0.05).

Conclusion

The senescence of human glomerular mesangial cells is associated with defective autophagy level under high glucose condition.Metformin could postpone high glucose - induced senescence of human glomerular mesangial cells by increasing aotophagy level via modulating AMPK/mTOR pathway.

Funding

  • Government Support - Non-U.S.