title: [Protective effect of glucagon-like peptide-1 analogue on cardiomyocytes injury induced by hypoxia/reoxygenation].
abstract: OBJECTIVE
  To investigate the effect of glucagon-like peptide-1 (GLP-1) receptor agonist liraglutide on hypoxia/reoxygenation (H/R)-induced cardiomyocytes death under high glucose condition and the potential mechanisms.
  
  
  METHODS
  H9C2 cardiomyocytes were divided into 4 groups: normal glucose (N, 5 mmol/L), high glucose (G, 20 mmol/L), high glucose in combination with liraglutide (L, 100 nmol/L), high glucose in combination with liraglutide and wortmannin (W, 25 nmol/L). The apoptosis of H9C2 was detected by TUNEL assay. Nitric oxide synthetase(eNOS), nitric oxide (NO) and reactive oxygen(ROS) in supernatants were measured by enzymatic analysis. p-PI3K, PI3K, p-Akt, Akt, Bcl-2, caspase-3 were examined by western blotting.
  
  
  RESULTS
  Compared with cells in N group, the apoptosis of H9C2 cells induced by H/R was markedly increased [(15.79±3.92)% vs (9.74±1.14)%, P=0.028] in G group. The same was true for ROS [(489.63±21.01) U/ml vs (338.50±43.60) U/ml, P<0.001] and caspase-3 levels (1.87±0.03 vs 1.15±0.04, P<0.001), but not for Bcl-2 protein expression (1.79±0.06 vs 1.89±0.03, P=0.047). Pretreatment of cells with liraglutide (100 nmol/L) prevented the cell death induced by high glucose and H/R together with decrease of ROS and caspase-3 levels and increase of Bcl-1 expression. Moreover, treatment of cells with liraglutide also significantly increased phosphorylation of PI3K and Akt (p-PI3K/PI3K: 0.87±0.07 vs 0.59±0.09, P=0.002; p-Akt/Akt: 0.34±0.01 vs 0.08±0.01, P<0.001), eNOS[(41.29±0.56)μmpl/L vs (37.20±0.52)μmpl/L, P<0.001)and NO [(31.24±0.40)μmpl/L vs (26.66±0.53)μmpl/L, P<0.001)levels. Furthermore, addition of PI3K/Akt inhibitor wortmanin markedly inhibited the expression of p-PI3K/PI3K, p-Akt/Akt, reversed the changes of eNOS, NO, caspase-3 and Bcl-2 by liraglutide, and abolished the protective effect of liraglutide on cell apoptosis.
  
  
  CONCLUSIONS
  GLP-1 receptor agonist liraglutide treatment could alleviate cardiomyocytes apoptosis induced by high glucose and H/R through the activation of PI3K-Akt-eNOS-NO signaling pathway and inhibition of oxidative stress.
authors.affiliation: Department of Endocrinology and Metabolism, Institute of Endocrinology and Metabolism of Jiangxi Province, the Second Affiliated Hospital of Nanchang University, Nanchang 330006, China.
authors.forename: M M
authors.initials: MM
authors.lastname: Liu
authors.forename: Y F
authors.initials: YF
authors.lastname: Shen
authors.forename: C
authors.initials: C
authors.lastname: Chen
authors.forename: X Y
authors.initials: XY
authors.lastname: Lai
authors.forename: M Y
authors.initials: MY
authors.lastname: Zhang
authors.forename: R
authors.initials: R
authors.lastname: Yu
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D052216:Glucagon-Like Peptide 1 / Q000031:analogs & derivatives* / Q000494:pharmacology; D005947:Glucose / Q000494:pharmacology*; D000860:Hypoxia; D000069450:Liraglutide; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III; D018384:Oxidative Stress; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D015427:Reperfusion Injury / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects*
chemical_list: D000069450:Liraglutide; D052216:Glucagon-Like Peptide 1; C496314:NOS3 protein, human; D052250:Nitric Oxide Synthase Type III; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; D005947:Glucose