Biochemical Markers in Parkinson's Disease

The Parkinson’s (PD) disease is a difficult health problem. Aging is the only probable cause of PD without clearly identified underlying molecular mechanisms. Still, it seems that oxidative stress and mitochondrial damage combined with harmful genetic and environmental factors are the main origins of death in dopaminergic neurons from substantia nigra pars compacta. While influx of new findings on pathogenesis, and development of new diagnostics for PD is increasing, still it diagnosis mostly depends on the physical examination and clinical diagnostic criteria with high misdiagnose rate. This is further complicated with fluctuation of the PD symptoms over the time and hinders objective and unbiased monitoring of the disease progression. PD is often diagnosed in the advanced stage and when majority of dopaminergic neurons are lost, so neuroprotective therapies are not possible. Given the difficulties with clinical diagnosis of the PD there is a pressing need to identify reliant diagnostic biomarkers. Intensively tested biomarker candidates are α- synuclein, DJ-1, 8-hydroxy-2'deoxyguanosine, 8- hydroxyguanosine, glutathione S-Transferase Pi protein for oxidative damage, and homocysteine with C-reactive protein as inflammatory biomarkers. Currently none of them are not enough specific and selective. Biomarkers with potentially good specificity, selectivity and accessibility are miRNAs, able to provide precise and non-invasive diagnosis. More fundamental research is warranted to provide critical data to determine real reasons behind the PD. Parallel to obtaining data for the origins of the PD, development of the suitable clinical biomarkers should follo