title: Taurine buffers glutamate homeostasis in retinal cells in vitro under hypoxic conditions.
abstract: OBJECTIVE
  We investigated whether taurine indirectly protects neurons under hypoxia by affecting retinal Müller cells, which are known to play important roles in the regulation of retinal glutamate content.
  
  
  METHODS
  Retinal cells isolated from rats were exposed to hypoxia for 24 h. We evaluated the retinal neuron survival, glutamate content in cultures with and without taurine under hypoxic conditions. The glutamate clearance function correlated with the expression of glutamine synthetase (GS) mRNA and L-glutamate/L-aspartate transporter (GLAST) mRNA. Immunohistochemical staining of glial fibrillary acidic protein (GFAP), vimentin and S-100 protein was performed to examine cytoskeletal changes in retinal Müller cells.
  
  
  RESULTS
  Retinal neurons treated with taurine exhibited significantly higher survival rates than those without taurine under hypoxia. Taurine inhibited the upregulation of GFAP and vimentin, and inhibited the downregulation of GLAST, GS and the nuclear-cytoplasmic ratio of S-100 under hypoxia. In addition, taurine inhibited the upregulation of the glutamate content in neurons and retinal Müller cells upon hypoxic exposure.
  
  
  CONCLUSIONS
  These data suggest that hypoxic damage to cultured retinal cells is decreased by taurine. The neuroprotection by taurine may relate to buffering glutamate homeostasis via modulation of the glutamate clearance by retinal Müller cells.
authors.affiliation: Department of Nutrition and Food Hygiene, Chongqing Key Laboratory of Nutrition and Food Safety, Third Military Medical University, Chongqing, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Chen
authors.forename: Mantian
authors.initials: M
authors.lastname: Mi
authors.forename: Qianyong
authors.initials: Q
authors.lastname: Zhang
authors.forename: Na
authors.initials: N
authors.lastname: Wei
authors.forename: Ka
authors.initials: K
authors.lastname: Chen
authors.forename: Hongxia
authors.initials: H
authors.lastname: Xu
authors.forename: Jialin
authors.initials: J
authors.lastname: Yuan
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhou
authors.forename: Haibin
authors.initials: H
authors.lastname: Lang
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Yu
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.forename: Yong
authors.initials: Y
authors.lastname: Tang
authors.forename: Hui
authors.initials: H
authors.lastname: Chang
mesh_terms: D027322:Amino Acid Transport System X-AG / Q000235:genetics; D000818:Animals; D002021:Buffers; D002470:Cell Survival; D002478:Cells, Cultured; D019084:Fluorescent Antibody Technique, Indirect; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D005974:Glutamate-Ammonia Ligase / Q000235:genetics; D018698:Glutamic Acid / Q000378:metabolism*; D006706:Homeostasis / Q000502:physiology*; D000860:Hypoxia / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D055351:Retinal Neurons / Q000187:drug effects* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D009418:S100 Proteins / Q000378:metabolism; D013654:Taurine / Q000494:pharmacology*; D014746:Vimentin / Q000378:metabolism
chemical_list: D027322:Amino Acid Transport System X-AG; D002021:Buffers; D005904:Glial Fibrillary Acidic Protein; D012333:RNA, Messenger; D009418:S100 Proteins; D014746:Vimentin; D013654:Taurine; D018698:Glutamic Acid; D005974:Glutamate-Ammonia Ligase