mRNA expression profiling of mitochondrial subunits in subjects with Parkinson's disease

Introduction: Parkinson's disease (PD) is a common adult-onset neurode-generative disorder caused by a progressive loss of dopaminergic neurons due to the accumulation of & alpha;-synuclein in the substantia nigra. Mitochon-dria are known to play a key role in cell respiratory function and bioenerget-ics. Indeed, mitochondrial dysfunction causes insufficient energy production required to satisfy the needs of several organs, especially the nervous sys-tem. However, the profiling of messenger RNA (mRNA) expression of mito-chondrial subunits in PD has not been systematically investigated yet.Material and methods: We explored the mRNA expression of mitochondrial DNA (mtDNA) encoded respiratory chain (RC) subunits in 43 PD patients and 43 normal controls (NC). Next generation sequencing analysis (NGS) was used and quantitative real-time polymerase chain reaction (qRT-PCR) assay was used for confirmation of the NGS results.Results: All tested mitochondrial RC subunits were significantly over -ex-pressed in subjects with PD compared to NC. In qRT-PCR the mean expres-sion of all mitochondrial subunits had an expression level of at least 7 times compared to NC.Conclusions: The over-expression of mitochondrial subunits in PD subjects with respect to NC might be secondary to a degeneration-related alteration of the mitochondrial structure and/or dynamics, or to the occurrence of a compensa-tory mechanism. The study of specific mRNA by peripheral blood mononuclear cells may provide a further diagnostic frame for early detection PD patients.