title: Apoptotic Retinal Ganglion Cell Death After Optic Nerve Transection or Crush in Mice: Delayed RGC Loss With BDNF or a Caspase 3 Inhibitor.
abstract: OBJECTIVE
  To investigate retinal ganglion cell (RGC) survival and activation of caspase 3 after optic nerve crush (ONC) or transection (ONT) and treatment with brain-derived neurotrophic factor (BDNF) or Z-DEVD_fmk.
  
  
  METHODS
  In albino Swiss mice, the left optic nerve was severed or crushed at 0.5 mm from the optic head and retinas were analyzed from 1 to 10 days. Additional groups were treated intravitreally with a single injection of BDNF (2.5 μg) or Z-DEVD_fmk (125 ng) right after injury, or with Z-DEVD_fmk at day 2, or with multiple injections of Z-DEVD_fmk. As controls intact or vehicle-treated retinas were used. In all retinas, Brn3a (RGCs) and cleaved-caspase 3 (c-casp3) were immunodetected and their numbers quantified. In an additional group, c-casp3 expression was assessed in RGCs retrogradely labeled before axotomy.
  
  
  RESULTS
  The temporal loss of RGCs was the same after ONC or ONT and occurred in two phases with 65% loss during the first 7 days and an additional 4% loss from day 7 to 10. The appearance of c-casp3+RGCs is Gaussian, peaking at 4 days and declining thereafter. Brn3a down-regulates when RGCs start expressing c-casp3. Retinal ganglion cell rescue rate for BDNF or Z-DEVD_fmk is similar and both delay RGC loss by 1 day. Delayed treatment with Z-DEVD_fmk does not rescue RGCs, and several injections are not better than a single one at the time of the injury.
  
  
  CONCLUSIONS
  Brn3a down-regulation marks the beginning of RGC death, which after axotomy occurs by caspase-dependent apoptosis in at least half of the RGCs. These data should be considered when designing neuroprotective strategies.
authors.forename: Maria C
authors.initials: MC
authors.lastname: Sánchez-Migallón
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Valiente-Soriano
authors.forename: Francisco M
authors.initials: FM
authors.lastname: Nadal-Nicolás
authors.forename: Manuel
authors.initials: M
authors.lastname: Vidal-Sanz
authors.forename: Marta
authors.initials: M
authors.lastname: Agudo-Barriuso
mesh_terms: D000818:Animals; D017209:Apoptosis; D019208:Brain-Derived Neurotrophic Factor / Q000494:pharmacology*; D053148:Caspase 3 / Q000187:drug effects*; D002470:Cell Survival; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D004195:Disease Models, Animal; D008297:Male; D051379:Mice; D009842:Oligopeptides / Q000494:pharmacology*; D009900:Optic Nerve / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D020221:Optic Nerve Injuries / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D012165:Retinal Ganglion Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D015853:Cysteine Proteinase Inhibitors; D009842:Oligopeptides; C110772:benzoylcarbonyl-aspartyl-glutamyl-valyl-aspartyl-fluoromethyl ketone; C579455:BDNF protein, human; D053148:Caspase 3