title: Apelin-13 regulates proliferation, migration and survival of retinal Müller cells under hypoxia.
abstract: OBJECTIVE
  To investigate the effect of apelin-13 and the antagonist of apelin receptor (F13A) on retinal Müller cells in vitro.
  
  
  METHODS
  Localization of apelin-13, GFAP and VEGF of Müller cells was detected by immunofluorescence. The effects of apelin-13 and F13A on cell function were assessed by MTT, spreading assay, apoptosis and Boyden chamber assay in vitro. Additionally, the mRNA and protein of apelin-13, GFAP and VEGF in cultured Müller cells were measured by real-time PCR and western blot.
  
  
  RESULTS
  Under hypoxia, strong positive staining of apelin-13 was observed and particularly evident in the cytosol and around the nucleus. Exposure of Müller cells to hypoxia led to a progressive increase in mRNA (p<0.01) and protein levels of apelin-13 (p<0.01), with a maximal 2.5-fold and 2-fold stimulation at 4h respectively, compared with normoxic controls. Treated with 0.1, 1, 10 and 100 ng/ml apelin-13, the protein level of GFAP (p<0.01) and VEGF (p<0.01) increased significantly in Müller cells in a dose-dependent manner after 24h. Compared with the untreated cells, 10 ng/ml apelin-13 significantly promoted Müller cells migration (p<0.01). Annexin/PI staining showed that apelin-13 can downregulate cell apoptosis with 30% to the most (p<0.05). On the contrary, 20 ng/ml F13A-treated Müller cells spread less than the control cells, with significantly lower number of migrated cells and significantly higher rate of apoptosis.
  
  
  CONCLUSIONS
  The results of this study showed that apelin-13 modulated the proliferation, migration, spreading, survival of Müller cells and the expressions of GFAP and VEGF.
authors: Department of Ophthalmology, People's Hospital, Peking University, Beijing, China.
authors: Qiang
authors: Q
authors: Lu
authors: Yan-Rong
authors: YR
authors: Jiang
authors: Jing
authors: J
authors: Qian
authors: Yong
authors: Y
authors: Tao
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects*; D002478:Cells, Cultured; D036341:Intercellular Signaling Peptides and Proteins / Q000494:pharmacology*; D011817:Rabbits; D012160:Retina / Q000166:cytology / Q000378:metabolism
chemical_list: D036341:Intercellular Signaling Peptides and Proteins; C495199:apelin-13 peptide; C532492:apelin-13, Ala(13)-