title: The Effect of A2A Receptor Antagonist on Microglial Activation in Experimental Glaucoma.
abstract: OBJECTIVE
  We investigated the effect of A2A receptor (A2AR) antagonist on microglial activation and retinal ganglion cell (RGC) survival under chronic ocular hypertension (COH), and explored the relationship between microglial activation and RGC survival by means of in vitro and in vivo experiments.
  
  
  METHODS
  An animal model of COH was induced in one eye of male Sprague-Dawley (SD) rats by ligation of three episcleral veins. The survival of RGCs and the activation of microglia under COH without or with intravitreous injection of A2AR antagonist ZM241385 were assessed by fluorescent labeling, real time PCR and Western blot. ELISA was used to measure the secretion of inflammatory mediators by microglia when glutamate and/or ZM241385 was added into the culture system.
  
  
  RESULTS
  Compared to the baseline, RGC density 2 weeks after COH induction decreased at the central (2436 ± 143 cells/mm2 pre- and 2130 ± 148 cells/mm2 post-COH induction) and peripheral (2219 ± 140 cells/mm2 pre- and 1953 ± 142 cells/mm2 post-COH induction) retina. The microglia changed their ramified morphology to an amoeboid form with increase in TNF-α and IL-1β expression after COH. These changes, however, were ameliorated with intravitreous ZM241385 (RGC density only dropped to 2287 ± 135 cells/mm2). The upregulation of those proinflammatory cytokines secreted by microglia in vitro under high concentration of glutamate was downregulated when ZM241385 was added into the culture system.
  
  
  CONCLUSIONS
  A2AR antagonist ZM241385 could reduce the activation of microglia and downregulate the proinflammatory cytokines expression under the conditions of COH and high concentration of glutamate, which may be one of the mechanisms that protected RGCs in experimental glaucoma.
authors.affiliation: Department of Ophthalmology, Ruijin Hospital Affiliated Medical School, Shanghai Jiaotong University, Shanghai, China.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Liu
authors.affiliation: Shanghai Key Laboratory for Bone and Joint Diseases, Shanghai Institute of Traumatology and Orthopaedics, Ruijin Hospital Affiliated Medical School, Shanghai Jiaotong University, Shanghai, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Huang
authors.affiliation: Department of Ophthalmology, Ruijin Hospital Affiliated Medical School, Shanghai Jiaotong University, Shanghai, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Ophthalmology, Ruijin Hospital Affiliated Medical School, Shanghai Jiaotong University, Shanghai, China.
authors.forename: Zijian
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Department of Ophthalmology, Ruijin Hospital Affiliated Medical School, Shanghai Jiaotong University, Shanghai, China.
authors.forename: Shouyue
authors.initials: S
authors.lastname: Huang
authors.affiliation: Department of Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States 4Department of Pathology and Laboratory Medicine, Temple University Hospital, Philadelphia, Pennsylvania.
authors.forename: Xunda
authors.initials: X
authors.lastname: Luo
authors.affiliation: Shanghai Key Laboratory for Bone and Joint Diseases, Shanghai Institute of Traumatology and Orthopaedics, Ruijin Hospital Affiliated Medical School, Shanghai Jiaotong University, Shanghai, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Qi
authors.affiliation: Department of Ophthalmology, Ruijin Hospital Affiliated Medical School, Shanghai Jiaotong University, Shanghai, China.
authors.forename: Xi
authors.initials: X
authors.lastname: Shen
authors.affiliation: Department of Ophthalmology, Ruijin Hospital Affiliated Medical School, Shanghai Jiaotong University, Shanghai, China.
authors.forename: Yisheng
authors.initials: Y
authors.lastname: Zhong
mesh_terms: D058917:Adenosine A2 Receptor Antagonists / Q000008:administration & dosage*; D000818:Animals; D015153:Blotting, Western; D002452:Cell Count; D002478:Cells, Cultured; D002908:Chronic Disease; D016207:Cytokines / Q000096:biosynthesis / Q000235:genetics*; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D005901:Glaucoma / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D007150:Immunohistochemistry; D058449:Intravitreal Injections; D008297:Male; D017628:Microglia / Q000187:drug effects* / Q000378:metabolism; D009798:Ocular Hypertension / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D012313:RNA / Q000235:genetics*; D051381:Rats; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction; D012165:Retinal Ganglion Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D014227:Triazines / Q000008:administration & dosage*; D014230:Triazoles / Q000008:administration & dosage*
chemical_list: D058917:Adenosine A2 Receptor Antagonists; D016207:Cytokines; D014227:Triazines; D014230:Triazoles; C097270:ZM 241385; D012313:RNA