Background/Aims: Aggregation of insoluble α-synuclein to form Lewy bodies (LBs) may contribute to the selective loss of midbrain dopaminergic neurons in Parkinson disease (PD). Lack of robust animal models has impeded elucidation of the molecular mechanisms of LB formation and other critical aspects of PD pathogenesis. Methods: We established a mouse model with targeted deletion of the plasminogen-binding protein tetranectin (TN) gene (TN^-/-) and measured the behavioral and histopathological features of PD. Results: Aged (15-to 20-month-old) TN^-/- mice displayed motor deficits resembling PD symptoms, including limb rigidity and both slower ambulation (bradykinesia) and reduced rearing activity in the open field. In addition, these mice exhibited more numerous α-synuclein-positive LB-like inclusions within the substantia nigra pars compacta (SNc) and reduced numbers of SNc dopaminergic neurons than age-matched wild type (WT) mice. These pathological changes were also accompanied by loss of dopamine terminals in the dorsal striatum. Conclusion: The TN^-/- mouse exhibits several key features of PD and so may be a valuable model for studying LB formation and testing candidate neuroprotective therapies for PD and other synucleinopathies.

Aims: To investigate alterations in protein expression associated with deep brain stimulation (DBS) in an attempt to elucidate possible mechanisms of action. Methods: Cerebrospinal fluid (CSF), obtained from six Parkinson's disease (PD) patients (pre- and post-DBS) and from six normal healthy controls, was studied for differentially expressed proteins. 2-D DIGE, in combination with MALDI-TOF and TOF-TOF Mass Spectrometry (MS) or ESI-MS, was used to identify the changed proteins (3 PD patients and 3 controls). Selected proteins were further studied using western blotting (6 PD patients and 6 controls). Results: Twenty-one proteins were identified after MS and protein database interrogation. Apart from apolipoprotein A-I (apoA-I), the expression levels of complement C4 (C4), IgA, tetranectin, and extracellular superoxide dismutase (EC-SOD), detected by western blotting, correlated well with the 2-D DIGE results. In the follow-up period, the expression levels of C4, apoA-I and IgA were stable whereas EC-SOD and tetranectin were significantly elevated. In addition, when DBS was ceased in one patient due to a suicide attempt, the levels of EC-SOD and tetranectin significantly decreased. Conclusion: Our preliminary results suggest that variations in the expression levels of EC-SOD and tetranectin in CSF is related to DBS.