The rat striatum responds to nigro-striatal degeneration via the increased expression of proteins associated with growth and regeneration of neuronal circuitry.
BACKGROUND
Idiopathic Parkinson's disease is marked by degeneration of dopamine neurons projecting from the substantia nigra to the striatum. Although proteins expressed by the target striatum can positively affect the viability and growth of dopaminergic neurons, very little is known about the molecular response of the striatum as nigro-striatal denervation progresses. Here, iTRAQ labelling and MALDI TOF/TOF mass spectrometry have been used to quantitatively compare the striatal proteome of rats before, during, and after 6-OHDA induced dopamine denervation.


RESULTS
iTRAQ analysis revealed the differential expression of 50 proteins at 3 days, 26 proteins at 7 days, and 34 proteins at 14 days post-lesioning, compared to the unlesioned striatum. While the denervated striatum showed a reduced expression of proteins associated with the loss of dopaminergic input (e.g., TH and DARPP-32), there was an increased expression of proteins associated with regeneration and growth of neurites (e.g., GFAP). In particular, the expression of guanine deaminase (GDA, cypin) - a protein known to be involved in dendritic branching - was significantly increased in the striatum at 3, 7 and 14 days post-lesioning (a finding verified by immunohistochemistry).


CONCLUSIONS
Together, these findings provide evidence to suggest that the response of the normal mammalian striatum to nigro-striatal denervation includes the increased expression of proteins that may have the capacity to facilitate repair and growth of neuronal circuitry.
Wolfson Centre for Inherited Neuromuscular Disease, RJAH Orthopaedic Hospital, Oswestry SY10 7AG, UK ; Keele University, Institute for Science and Technology in Medicine, Department of Life Sciences, Huxley Building, Keele ST5 5BG, UK.
Heidi R
HR
Fuller
Division of Neurobiology, The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK.
Maica Llavero
ML
Hurtado
Division of Neurobiology, The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK ; Euan MacDonald Centre for Motor Neuron Disease Research, University of Edinburgh, Edinburgh, UK.
Thomas M
TM
Wishart
Keele University, Institute for Science and Technology in Medicine, Department of Life Sciences, Huxley Building, Keele ST5 5BG, UK.
Monte A
MA
Gates
DARPP-32; GFAP; Guanine deaminase; Neurofilament; Nigro-striatal degeneration; Parkinson’s disease; Proteomics; Regeneration; Striatum; iTRAQ