title: Caspase inhibitors protect against NMDA-mediated retinal ganglion cell death.
abstract: BACKGROUND
  Apoptosis is a major mechanism of cell death in glutamate-induced excitotoxicity and caspases as the executors of apoptosis play an important role in the development of various central nervous system and eye diseases. We studied the involvement of certain caspases in excitotoxic retinal ganglion cell death, which was experimentally induced in Brown Norway Rats by application of the glutamate receptor agonist N-methyl-D-aspartate (NMDA).
  
  
  METHODS
  Animals were injected intravitreally with one of six caspase inhibitors (against caspases 1, 3, 4, 6, 8 and 9). Seven hours later, NMDA or phosphate-buffered saline as a control was injected intravitreally into the respective eyes. The neuroprotective potential against NMDA toxicity was assessed by retinal ganglion cell quantification. Additionally, wholemount TUNEL was performed.
  
  
  RESULTS
  Statistical analysis revealed significant neuroprotective effects for the inhibitors of caspases 3, 6, 8 and 9, but not for those of caspases 1 and 4. The inhibitors of caspases 6 and 9 showed greater neuroprotective potential than those of caspases 3 and 8, although cell death was not entirely averted in any case. Results of ganglion cell counts were confirmed for the most pronounced treatment groups using wholemount TUNEL.
  
  
  CONCLUSIONS
  Excitotoxic retinal ganglion cell death after NMDA injection is mediated mainly through apoptosis, whereby extrinsic as well as intrinsic pathways of caspase activation play a role.
authors.affiliation: Centre for Ophthalmology, University of Tuebingen, Tuebingen, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Schuettauf
authors.forename: Thomas
authors.initials: T
authors.lastname: Stein
authors.forename: Tomasz J
authors.initials: TJ
authors.lastname: Choragiewicz
authors.forename: Robert
authors.initials: R
authors.lastname: Rejdak
authors.forename: Sylvia
authors.initials: S
authors.lastname: Bolz
authors.forename: David
authors.initials: D
authors.lastname: Zurakowski
authors.forename: Meghana A
authors.initials: MA
authors.lastname: Varde
authors.forename: Alan M
authors.initials: AM
authors.lastname: Laties
authors.forename: Sebastian
authors.initials: S
authors.lastname: Thaler
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D061945:Caspase Inhibitors; D002452:Cell Count; D002470:Cell Survival; D019610:Cytoprotection; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D018690:Excitatory Amino Acid Agonists / Q000633:toxicity*; D005260:Female; D020287:In Situ Nick-End Labeling; D058449:Intravitreal Injections; D016202:N-Methylaspartate / Q000633:toxicity*; D051381:Rats; D011914:Rats, Inbred BN; D020318:Rats, Long-Evans; D012165:Retinal Ganglion Cells / Q000187:drug effects / Q000473:pathology*
chemical_list: D061945:Caspase Inhibitors; D004791:Enzyme Inhibitors; D018690:Excitatory Amino Acid Agonists; D016202:N-Methylaspartate