title: Adrenomedullin22-52 suppresses high-glucose-induced migration, proliferation, and tube formation of human retinal endothelial cells.
abstract: OBJECTIVE
  To investigate the roles of an adrenomedullin receptor antagonist (adrenomedullin(22-52)) on high-glucose-induced human retinal endothelial cell (HREC) in vitro cell biology.
  
  
  METHODS
  HRECs were cultured with different concentrations of glucose and adrenomedullin(22-52). The proliferation of HRECs was evaluated by a cell counting kit-8 assay. Cell migration was assessed by scratch wound assay, and cell sprouting was detected by tube formation assay. The mRNA levels of adrenomedullin (ADM), vascular endothelial growth factor (VEGF), ADAMTS-1, and TSP-1 were measured by reverse-transcription polymerase chain reaction (RT-PCR). The VEGF and phosphatidylinositol 3' kinase (PI3K) pathway protein expression levels were assessed by western blot analysis.
  
  
  RESULTS
  Compared with 5 mM normal glucose treatment, 30 mM glucose significantly promoted the migration of HRECs, which was attenuated by 1 μg/ml adrenomedullin(22-52). The proliferation of HRECs was also suppressed by 1 μg/ml adrenomedullin(22-52). Furthermore, compared with other groups, 5 μg/ml of adrenomedullin(22-52) was shown to suppress high-glucose-induced tube formation of HRECs. With adrenomedullin(22-52) treatment, the mRNA level of ADAMTS-1 was significantly increased. Moreover, western blot and RT-PCR analyses showed that HRECs treated with 30 mM glucose exhibited increased VEGF and PI3K pathway protein levels, while the expression levels were suppressed by 5 μg/ml of adrenomedullin(22-52).
  
  
  CONCLUSIONS
  Our study indicated that adrenomedullin(22-52) mediated the migration, proliferation and tube formation after HRECs were exposed to high levels of glucose, which may be related to its ability to affect the expression of VEGF through the PI3K pathway.
authors.affiliation: Department of Ophthalmology, the First Affiliated Hospital of Soochow University, Suzhou, China PR.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Department of Ophthalmology, the First Affiliated Hospital of Soochow University, Suzhou, China PR ; Jiangsu Clinical Immunology Institute, the First Affiliated Hospital of Soochow University, Suzhou, China PR.
authors.forename: Gaoqin
authors.initials: G
authors.lastname: Liu
authors.affiliation: Department of Ophthalmology, the First Affiliated Hospital of Soochow University, Suzhou, China PR.
authors.forename: Yanhui
authors.initials: Y
authors.lastname: Xiao
authors.affiliation: Department of Ophthalmology, the First Affiliated Hospital of Soochow University, Suzhou, China PR ; Jiangsu Clinical Immunology Institute, the First Affiliated Hospital of Soochow University, Suzhou, China PR.
authors.forename: Peirong
authors.initials: P
authors.lastname: Lu
mesh_terms: D051722:ADAM Proteins / Q000235:genetics / Q000378:metabolism; D000071097:ADAMTS1 Protein; D053607:Adrenomedullin / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D002196:Capillaries / Q000187:drug effects; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D004789:Enzyme Activation / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects; D005947:Glucose / Q000494:pharmacology*; D006801:Humans; D009389:Neovascularization, Pathologic / Q000473:pathology*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012160:Retina / Q000473:pathology*; D015398:Signal Transduction / Q000187:drug effects; D019700:Thrombospondin 1 / Q000235:genetics / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D019700:Thrombospondin 1; D042461:Vascular Endothelial Growth Factor A; D053607:Adrenomedullin; D019869:Phosphatidylinositol 3-Kinases; D051722:ADAM Proteins; D000071097:ADAMTS1 Protein; C103859:ADAMTS1 protein, human; D005947:Glucose