Microglial neuroinflammatory processes play a primary role in dopaminergic neurodegeneration for Parkinson's disease (PD). This can occur, in part, by modulation of glial function following activation by soluble or insoluble modified alphasynuclein (a-syn), a chief component of Lewy bodies that is released from affected dopaminergic neurons. a-Syn is nitrated during oxidative stress responses and in its aggregated form, induces inflammatory microglial functions. Elucidation of these microglial function changes in PD could lead to new insights into disease mechanisms. To this end, PD-associated inflammation was modeled by stimulation of microglia with aggregated and nitrated a-syn. These activated microglia were ameboid in morphology and elicited dopaminergic neurotoxicity. A profile of nitrated, aggregated a-syn-stimulated microglia was generated using combinations of genomic (microarrays) and proteomic (liquid chromatography-tandem mass spectrometry, differential gel electrophoresis, and protein array) assays. Genomic studies revealed a substantive role for nuclear factor-kappa B transcriptional activation. Qualitative changes in the microglial proteome showed robust increases in inflammatory, redox, enzyme, and cytoskeletal proteins supporting the genomic tests. Autopsy brain tissue acquired from substantia nigra and basal ganglia of PD patients demonstrated that parallel nuclear factor-kappa B-related inflammatory processes were, in part, active during human disease. Taken together, the transcriptome and proteome of nitrated a-syn activated microglia, shown herein, provide new potential insights into disease mechanisms.

Advanced HIV-1 infection is commonly associated with progressive immune suppression and the development of cognitive, motor, and behavior disturbances. In its most severe form, it is diagnosed as HIV-1 associated dementia (HAD) and can progress to profound functional disability and death. Despite prodigious efforts to uncover biomarkers of HAD, none can adequately reflect disease onset or progression. Thus, we developed a proteomics platform for HAD biomarker discovery and used it to perform a pilot study on cerebrospinal fluid (CSF) from HIV-1-infected people with or without HAD. A 2-dimensional electrophoresis (2-DE) map of a HAD CSF proteome was focused on differentially expressed proteins. 2-DE difference gel electrophoresis (2-D DIGE) analysis showed >90 differences in protein spots of which 20 proteins were identified. Differential expression of 6 proteins was validated by Western blot tests and included vitamin D binding protein, clusterin, gelsolin, complement C3, procollagen C-endopeptidase enhancer 1, and cystatin C. We posit that these proteins, alone or together, are potential HAD biomarkers.