title: Metformin inhibits nuclear factor-κB activation and inflammatory cytokines expression induced by high glucose via adenosine monophosphate-activated protein kinase activation in rat glomerular mesangial cells in vitro.
abstract: BACKGROUND
  The renoprotective mechanisms of adenosine monophosphate (AMP)-activated protein kinase (AMPK) agonist - metformin have not been stated clearly. We hypothesized that metformin may ameliorate inflammation via AMPK interaction with critical inflammatory cytokines. The aim of this study was to observe the effects of metformin on expression of nuclear factor-κB (NF-κB), monocyte chemoattractant protein-1 (MCP-1), intercellular adhesion molecule-1 (ICAM-1) and transforming growth factor-beta 1 (TGF-β1) induced by high glucose (HG) in cultured rat glomerular mesangial cells (MCs).
  
  
  METHODS
  MCs were cultured in the medium with normal concentration glucose (group NG, 5.6 mmol/L), high concentration glucose (group HG, 25 mmol/L) and different concentrations of metformin (group M1, M2, M3). After 48-hour exposure, the supernatants and MCs were collected. The expression of NF-κB, MCP-1, ICAM-1, and TGF-β1 mRNA was analyzed by real time polymerase chain reaction. Western blotting was used to detect the expression of AMPK, phospho-Thr-172 AMPK (p-AMPK), NF-κB p65, MCP-1, ICAM-1, and TGF-β1 protein.
  
  
  RESULTS
  After stimulated by HG, the expression of NF-κB, MCP-1, ICAM-1, TGF-β1 mRNA and protein of MCs in group HG increased significantly compared with group NG (P < 0.05). Both genes and protein expression of NF-κB, MCP-1, ICAM-1, TGF-β1 of MCs induced by high glucose were markedly reduced after metformin treatment in a dose-dependent manner (P < 0.05). The expression of p-AMPK increased with the rising of metformin concentration, presenting the opposite trend, while the level of total-AMPK protein was unchanged with exposure to HG or metformin. Conlusion Metformin can suppress the expression of NF-κB, MCP-1, ICAM-1 and TGF-β1 of glomerular MCs induced by high glucose via AMPK activation, which may partly contribute to its reno-protection.
authors.affiliation: Department of Endocrinology, Anhui Provincial Hospital Affiliated to Anhui Medical University, Hefei, Anhui 230001, China.
authors.forename: Junfei
authors.initials: J
authors.lastname: Gu
authors.affiliation: Department of Endocrinology, Anhui Provincial Hospital Affiliated to Anhui Medical University, Hefei, Anhui 230001, China. Email: ysd196406@163.com.
authors.forename: Shandong
authors.initials: S
authors.lastname: Ye
authors.affiliation: Department of Endocrinology, Anhui Provincial Hospital Affiliated to Anhui Medical University, Hefei, Anhui 230001, China.
authors.forename: Shan
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Endocrinology, Anhui Provincial Hospital Affiliated to Anhui Medical University, Hefei, Anhui 230001, China.
authors.forename: Wenjia
authors.initials: W
authors.lastname: Sun
authors.affiliation: Department of Endocrinology, Anhui Provincial Hospital Affiliated to Anhui Medical University, Hefei, Anhui 230001, China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Hu
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000378:metabolism*; D000818:Animals; D002478:Cells, Cultured; D005920:Glomerular Mesangium / Q000166:cytology; D005947:Glucose / Q000494:pharmacology*; D050527:Mesangial Cells / Q000187:drug effects* / Q000378:metabolism*; D008687:Metformin / Q000494:pharmacology*; D016328:NF-kappa B / Q000378:metabolism*; D051381:Rats
chemical_list: D016328:NF-kappa B; D008687:Metformin; D055372:AMP-Activated Protein Kinases; D005947:Glucose