Studies of MIR-7, MIR-153 and MIR-214 in blood of patients with Parkinson’s disease

Abstract

Parkinson’s Disease (PD) is the second most common progressive neurodegenerative disorder that is characterized by both motor and non-motor manifestations. Motor symptoms include resting tremor, bradykinesia (slow movement), rigidity, shuffling gait, and postural instability. Non-motor symptoms of PD are cognitive changes, behavioral/neuropsychiatric changes, autonomic nervous system failure, sensory and sleep disturbances [1]. Considering the accuracy of clinical diagnosis of PD is currently inadequate and there is no reliable quantitative diagnostic test for PD, molecular biomarkers could be potential clinical tools to ease early and accurate PD diagnosis [2,3]. For example, circulating plasma miRNAs could possibly be used as one of the non-invasive biomarkers, facilitating the early detection of PD and monitoring the progression of the pathology [2]. However, more research is needed to further evaluate the potential of miRNAs and other small molecules as candidate biomarkers before application in clinical practice [4]. The aim of the study was to investigate miR-7, miR-153, miR-214 expression in blood samples that were collected from patients with PD who received DBS or Gamma knife surgery, examine if there were any differences and try to link the results with clinical symptoms and other patient-related data. First of all, blood samples were centrifuged, and serum was collected. Extracellular vesicle miRNA was then isolated from blood serums and miRNA cDNA was synthesized. The expression levels of miR-7, miR-153, miR-214 were evaluated by RT-PCR in 42 samples of patients, who underwent DBS surgery, 16 samples of patients, who underwent Gamma knife surgery, and 37 samples of PD control group patients. After observation, the results showed that the difference between the expression levels of miR-7, miR- 153 and miR-214 was statistically significant. The statistical analysis of the results showed that miR-7 expression is significantly different between the control group and the DBS group (p ≤ 0,05). Furthermore, the results showed that miR-214 expression levels between patients with first and forth level of bradykinesia were statistically different (p ≤ 0,01). Moreover, the results showed that miR-214 expression is positively correlated with the age of the patients (p ≤ 0,05). Lastly, statistical analysis showed a positive correlation between expression of miR-7 and the duration of PD (p ≤ 0,01). In conclusion, the different miRNA expression levels in PD blood serum samples showed patient heterogeneity and indicate a potential role of miRNA in PD pathogenesis, however more research is still required.