The Relationship Between Plasma MiR-137 And MiR-124 And Parkinson's Disease And Non-motor Symptoms

Objective: Parkinson's disease(PD)is a debilitating neuro-degenerative disorder causing severe motor disabilities,as well as non-motor symptoms(NMS),including depression,hyposmia,dementia,and so on.Depression is one of the most common non-motor symptoms(NMS)observed in Parkinson's disease(PD),affecting approximately 40% of patients and reducing quality of life independent of motor symptoms.Micro RNAs(mi RNAs)are a class of small,non-coding RNAs that regulate gene expression at the post-transcriptional level.Recently,it was reported that mi R-137,mi R-124 and mi R-184 were widely expressed in the central nervous system and were vital to neuronal regulation.In this study,we detected the circulating levels of mi R-137,mi R-124 and mi R-184 in PD patients and explored the potential role of mi R-124,mi R-137 and mi R-184 in the diagnosis of PD.We further described the relationship between these mi RNAs and PD with depression(PD-Dep)and PD with cognitive dysfunction.Methods: The study recruited 120 subjects,including 60 controls and 60 consecutive patients with PD,and the latter were further divided into two subgroup,PD with depression(PD-Dep,n=24)and the non-depressed group(PD-NDep,n=36)according to Hamilton Rating Scale for Depression(HAMD).Divide PD patients into non dementia group of 38 cases and dementia group of 22 cases with MMSE rating scale.Plasma levels of mi R-137 and mi R-124 were detected by q RT-PCR.Receiver Operating Characteristic(ROC)curve was used to valuated circulating mi R-124 and mi R-137 as a potential diagnostic biomarkers of PD.Compare PD with depression and non-depression,dementia and non-dementia group plasma mi R-124 and mi R-137 levels.Results: 1.Compared with the controls,plasma levels of mi R-137 in PD patients increased significantly(P <0.05),while levels of mi R-124 was down-regulated(P <0.05).The results demonstrated that there were no signiffcant differences in levels of mi R-184 between PD patients and controls(P> 0.05).2.The areas under the ROC curve(AUC)of mi R-137 and mi R-124 were 0.707(95% CI 0.615-0.789,P <0.05)and 0.709(95% CI 0.618-0.633,P <0.05),respectively.The diagnostic sensitivity and specificity of mi R-137 were 78.3% and 56.7%,respectively;while those of mi R-124 were 66.7% and 63.3%,respectively.3.The correlation analysis revealed that there is no relationship between plasma level of mi R-137/124,UPDRS score and H&Y staging.4.Subgroup analysis showed that there were no significant differences in mi R-137 and mi R-124 levels between PD-Dep and PD-NDep(P> 0.05).5.There were no significant differences in mi R-137 and mi R-124 levels between PD with dementia and non-dementia(P> 0.05).Conclusions: Plasma levels of mi R-137 and mi R-124 are associated with Parkinson's disease,and might be potential biomarkers of the diagnosis of PD.However,there were no association between plasma mi R-137,mi R-124 and PD-Dep.There were no association between plasma mi R-137,mi R-124 and PD with dementia.