title: Pyrroloquinoline quinone protects mouse brain endothelial cells from high glucose-induced damage in vitro.
abstract: OBJECTIVE
  To investigate the effects of pyrroloquinoline quinone (PQQ), an oxidoreductase cofactor, on high glucose-induced mouse endothelial cell damage in vitro.
  
  
  METHODS
  Mouse brain microvascular endothelial bEND.3 cells were exposed to different glucose concentrations (5.56, 25 and 40 mmol/L) for 24 or 48 h. The cell viability was examined using MTT assay. Flow cytometry was used to analyze the apoptosis and ROS levels in the cells. MitoTracker Green staining was used to examine the mitochondria numbers in the cells. Western blot analysis was used to analyze the expression of HIF-1α and the proteins in JNK pathway.
  
  
  RESULTS
  Treatment of bEND.3 cells with high glucose significantly decreased the cell viability, while addition of PQQ (1 and 10 μmol/L) reversed the high glucose-induced cell damage in a concentration-dependent manner. Furthermore, PQQ (100 μmol/L) significantly suppressed the high glucose-induced apoptosis and ROS production in the cells. PQQ significantly reversed the high glucose-induced reduction in both the mitochondrial membrane potential and mitochondria number in the cells. The high glucose treatment significantly increased the expression of HIF-1α and JNK phosphorylation in the cells, and addition of PQQ led to a further increase of HIF-1α level and a decrease of JNK phosphorylation. Addition of JNK inhibitor SP600125 (10 μmol/L) also significantly suppressed high glucose-induced apoptosis and JNK phosphorylation in bEND.3 cells.
  
  
  CONCLUSIONS
  PQQ protects mouse brain endothelial cells from high glucose damage in vitro by suppressing intracellular ROS and apoptosis via inhibiting JNK signaling pathway.
authors.affiliation: Department of Cardiothoracic Surgery, The Affiliated Jiangyin Hospital of Southeast University, Jiangyin 214400, China.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Cardiothoracic Surgery, The Affiliated Jiangyin Hospital of Southeast University, Jiangyin 214400, China.
authors.forename: Guo-qiang
authors.initials: GQ
authors.lastname: Chen
authors.affiliation: Department of Cardiothoracic Surgery, The Affiliated Jiangyin Hospital of Southeast University, Jiangyin 214400, China.
authors.forename: Gui-ping
authors.initials: GP
authors.lastname: Yu
authors.affiliation: Department of Vascular Surgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing 210008, China.
authors.forename: Chang-jian
authors.initials: CJ
authors.lastname: Liu
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D001921:Brain / Q000098:blood supply*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D019610:Cytoprotection; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D005947:Glucose / Q000633:toxicity*; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism; D048031:JNK Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D051379:Mice; D055806:Microvessels / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011758:Pyrroles / Q000494:pharmacology*; D011804:Quinolines / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D000975:Antioxidants; C497443:Hif1a protein, mouse; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D047428:Protein Kinase Inhibitors; D011758:Pyrroles; D011804:Quinolines; D017382:Reactive Oxygen Species; C410406:pyrroloquinoline; D048031:JNK Mitogen-Activated Protein Kinases; D005947:Glucose