title: Astrocyte-conditioned medium attenuates glutamate-induced apoptotic cell death in primary cultured spinal cord neurons of rats.
abstract: OBJECTIVE
  To better understand the neuroprotective role of astrocytes in spinal cord injury (SCI), we investigated whether astrocyte-conditioned medium (ACM) can attenuate glutamate-induced apoptotic cell death in primary cultured spinal cord neurons.
  
  
  METHODS
  Spinal cord neurons were pretreated with ACM for 24 hours. Subsequently, they were exposed to glutamate (125 μM) for 1 hour. The neurons were then incubated for 24 hours. Following that, measurements assessing cell viability and lactate dehydrogenase (LDH) release were performed. Apoptosis was confirmed through cell morphology using Hoechst 33342 staining and terminal deoxynucleotidyl transferase dUTP-mediated nicked end labeling (TUNEL) assay. Assessment for expression of apoptotic enzymes, including Caspase-3, Bcl-2 and Bax, was performed using Western Blot Analysis.
  
  
  RESULTS
  Astrocyte-conditioned medium pretreatment of neurons showed both an increase in spinal cord neuron viability and a decrease in LDH release in a dose-dependent pattern. Moreover, pretreatment seems to attenuate glutamate-induced apoptotic cell death, antagonise glutamate-induced up-regulation of Caspase-3 expression and downregulate Bcl-2/Bax protein expression ratio.
  
  
  CONCLUSIONS
  By attenuating glutamate-induced apoptotic cell death in primary cultured spinal cord neurons of rats, ACM seems to provide a neuroprotective effect by regulating apoptosis-related protein expression. Our results provide an experimental basis for clinical applications and potential therapeutic use of ACM in SCI.
authors.forename: Xiaojian
authors.initials: X
authors.lastname: Lu
authors.forename: Rami
authors.initials: R
authors.lastname: Al-Aref
authors.forename: Dong
authors.initials: D
authors.lastname: Zhao
authors.forename: Jianhong
authors.initials: J
authors.lastname: Shen
authors.forename: Yaohua
authors.initials: Y
authors.lastname: Yan
authors.forename: Yilu
authors.initials: Y
authors.lastname: Gao
mesh_terms: D000818:Animals; D017209:Apoptosis; D001253:Astrocytes / Q000502:physiology*; D053148:Caspase 3 / Q000378:metabolism; D002470:Cell Survival; D017077:Culture Media, Conditioned; D018698:Glutamic Acid / Q000633:toxicity*; D009474:Neurons / Q000502:physiology*; D061251:Primary Cell Culture / Q000379:methods*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000502:physiology*; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: C494828:Bax protein, rat; D017077:Culture Media, Conditioned; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; D018698:Glutamic Acid; D053148:Caspase 3
keywords: Apoptosis,; Astrocyte-conditioned medium,; Glutamate,; Spinal cord neurons