Gene expression profiling of substantia nigra: a post-mortem study in Parkinson's disease and control subjects
Introduction: Parkinson's disease (PD) is characterized by bradykinesia, tremor, and rigidity; in addition, postural instability sets in as the disease progresses. Non-motor symptoms of the disease include cognitive, behavioral, and neuropsychiatric changes, sensory and sleep disturbances that may precede the motor symptoms of the disease itself. The peculiar pathological features of PD are decreased dopaminergic neurons and dopamine levels in the substantia nigra pars compacta and pontine locus ceruleus. The study of the transcriptome plays a major role in the identification of genes and gene regulatory mechanisms in multifactorial neurodegenerative diseases such as Parkinson's disease itself. Therefore, we proposed to study the transcriptome directly in the midbrain containing the "Substantia nigra.The study was performed in 8 subjects with PD and 6 normal control subjects, using next-generation sequencing (NGS) technologies. Results: With the use of an ad hoc bioinformatics pipeline, gene expression profiles in the different PD subjects were obtained and compared to those of controls. In detail, the results obtained from the data analysis indicated 92 differentially expressed genes (FDR-adjusted p value =0.05 and fold-change less than -1.5 or greater than +1.5) of which 33 genes were up-regulated while 59 were down-regulated. Conclusions: Functional analysis of the differentially expressed genes revealed several genes involved in different canonical pathways indicating their likely significant role in Parkinson's disease.