title: Retinal gene expression after central retinal artery ligation: effects of ischemia and reperfusion.
abstract: OBJECTIVE
  To investigate the morphologic and molecular consequences of 30- and 90-minute central retinal artery ligation (CRAL)-induced retinal ischemia, followed by 3 and 12 hours of reperfusion, and to identify potential targets for therapy.
  
  
  METHODS
  Retinal ischemia was induced for 30 and 90 minutes by ligating the rat central retinal artery, and corresponding effects were examined histologically, immunocytochemically, and molecularly at 3 hours and 12 hours of reperfusion. Patterns of gene expression revealed significantly upregulated and downregulated genes by gene array analyses and were verified by quantitative RT-PCR. Functional pathways were correlated using gene set enrichment analysis.
  
  
  RESULTS
  Substantial morphologic changes occurred from 3 hours to 7 days after CRAL in rats, resulting in a cellular loss in most retinal layers, particularly in inner nuclear and ganglion cell layers. After 30 minutes of CRAL and 3 hours of reperfusion, transcription-related genes such as ATF3, ID2, Klf4, BTG2, c-Fos, and c-Jun were activated. After 12 hours of reperfusion, the genes associated with kinase and caspase molecular pathways-including MAP kinases, Casp3 and Casp9-were upregulated. CRAL of 90 minutes and 3 hours of reperfusion induced glycolysis and gluconeogenesis-related genes such as G6PC. However, prolonged reperfusion of 12 hours was characterized by prominent activation of apoptosis-related genes, including Tp53, Akt1, Akt3, Pik3R1, Prkcb1, caspases (Casp3, Casp7, Casp9), and TNF.
  
  
  CONCLUSIONS
  CRAL is a clinically relevant retinal ischemia model, and gene expression analysis can provide information regarding the molecular mechanisms underlying the pathophysiological processes during retinal ischemia. In addition, CRAL represents an effective experimental model with which to study retinal inflammation, development, aging, and, neurodegeneration.
authors: Genomics Division, Biologics and Genetic Therapies Directorate, Health Canada, Ottawa, Ontario, Canada. shiv_prasad@hc-sc.gc.ca
authors: Shiv S
authors: SS
authors: Prasad
authors: Ljubomir
authors: L
authors: Kojic
authors: Yan H
authors: YH
authors: Wen
authors: Zheng
authors: Z
authors: Chen
authors: Wei
authors: W
authors: Xiong
authors: William
authors: W
authors: Jia
authors: Max S
authors: MS
authors: Cynader
mesh_terms: D000818:Animals; D051017:Apoptosis Regulatory Proteins / Q000235:genetics; D005136:Eye Proteins / Q000235:genetics*; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000502:physiology*; D020287:In Situ Nick-End Labeling; D007511:Ischemia / Q000235:genetics* / Q000378:metabolism / Q000503:physiopathology; D000090062:Kruppel-Like Factor 4; D008026:Ligation; D008297:Male; D009693:Nucleic Acid Hybridization; D020411:Oligonucleotide Array Sequence Analysis; D051381:Rats; D011917:Rats, Inbred Lew; D015427:Reperfusion Injury / Q000235:genetics* / Q000378:metabolism / Q000503:physiopathology; D012160:Retina / Q000378:metabolism*; D012161:Retinal Artery / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000235:genetics
chemical_list: D051017:Apoptosis Regulatory Proteins; D005136:Eye Proteins; C000715469:Klf4 protein, rat; D000090062:Kruppel-Like Factor 4; D014157:Transcription Factors