title: Knockdown of GAD67 protein levels normalizes neuronal activity in a rat model of Parkinson's disease.
abstract: BACKGROUND
  Dopamine depletion of the striatum is one of the hallmarks of Parkinson's disease. The loss of dopamine upregulates GAD67 expression in the striatal projection neurons and causes other changes in the activity of the basal ganglia circuit.
  
  
  METHODS
  To normalize the GAD67 expression in the striatum after dopamine depletion, we developed several lentiviral vectors that express RNA interference (RNAi) directed against GAD67 mitochondrial RNA. The vectors were injected into the striatum of hemiparkinsonian rats and the level of GAD67 protein as well as a marker of neuronal activity, mtCO1, was analyzed using western blots.
  
  
  RESULTS
  Unilateral lesions of the dopamine neurons in substantia nigra resulted in an increased level of GAD67 protein in the ipsilateral striatum. Furthermore, we detected significantly higher levels of mtCO1, after dopamine depletion in the striatum. Using a lentiviral vectors with a synthetic miRNA scaffold to deliver RNAi, we were able to normalize the GAD67 protein levels in the parkinsonian rat striatum. In addition, we were able to normalize the increased neural activity, which resulted from the loss of dopamine as measured by the marker mtCO1.
  
  
  CONCLUSIONS
  We conclude that RNAi directed against GAD67 may be a valid approach to correct the dysregulation of the basal ganglia circuit in a rat model of Parkinson's disease. The possibility to correct for a loss of dopamine using nondopamimetic tools is interesting because it may be more directed towards the casual mechanisms of the motor symptoms.
authors: CNS Gene Therapy Unit, Wallenberg Neuroscience Center, Department of Experimental Medical Science, Lund University, Lund, Sweden.
authors: Lazlo
authors: L
authors: Horvath
authors: Ingrid
authors: I
authors: van Marion
authors: Khalid
authors: K
authors: Taï
authors: Troels Tolstrup
authors: TT
authors: Nielsen
authors: Cecilia
authors: C
authors: Lundberg
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002460:Cell Line; D004195:Disease Models, Animal; D004298:Dopamine / Q000502:physiology*; D003576:Electron Transport Complex IV / Q000378:metabolism; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D055785:Gene Knockdown Techniques; D005822:Genetic Vectors; D005968:Glutamate Decarboxylase / Q000235:genetics* / Q000378:metabolism*; D049452:Green Fluorescent Proteins; D006801:Humans; D007150:Immunohistochemistry; D016086:Lentivirus / Q000235:genetics; D035683:MicroRNAs / Q000737:chemistry / Q000235:genetics; D008928:Mitochondria / Q000378:metabolism; D017072:Neostriatum / Q000201:enzymology* / Q000378:metabolism; D010300:Parkinson Disease / Q000378:metabolism*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000737:chemistry / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
chemical_list: D035683:MicroRNAs; D034741:RNA, Small Interfering; D049452:Green Fluorescent Proteins; D003576:Electron Transport Complex IV; D005968:Glutamate Decarboxylase; C402565:glutamate decarboxylase 1; D004298:Dopamine