ABSTRACT
Recently, we reported downregulated circulating levels of the microRNAs miR-19b, miR-29a, and miR-29c in Parkinson disease. Here we investigated the expression of these microRNAs in serum samples from 56 patients with idiopathic rapid eye movement sleep behavior disorder, before and after their conversion into a synucleinopathy. Compared to controls, we found that the expression level of miR-19b is downregulated in patients with idiopathic rapid eye movement sleep behavior disorder and antedates the diagnosis of Parkinson disease and dementia with Lewy bodies after 4.67 ± 2.61 years of follow-up. Our findings indicate that dysregulation of the microRNA miR-19b occurs in the prodromal stage of synucleinopathies.
Subject(s)
Disease Progression , MicroRNAs/blood , REM Sleep Behavior Disorder/blood , REM Sleep Behavior Disorder/diagnosis , Synucleins/blood , Aged , Biomarkers/blood , Female , Follow-Up Studies , Humans , Male , Middle AgedABSTRACT
BACKGROUND: Low levels of serum urate are associated with a higher risk of Parkinson's disease (PD). Higher serum and cerebrospinal fluid (CSF) urate levels are associated with slower rates of clinical decline in PD and in multiple system atrophy (MSA). AIMS: To compare CSF and blood urate levels in healthy controls, patients with synucleinopathies and with tauopathies. METHODS: We investigated urate levels in serum and CSF from 18 healthy controls, 19 patients with synucleinopathies (six patients with PD and 13 with MSA), and 24 patients with tauopathies (18 with progressive supranuclear palsy and six with corticobasal degeneration). None of the patients were treated with dopaminergic medications. RESULTS: No significant differences were seen when comparing serum and CSF urate levels from controls across the parkinsonian diagnostic groups. However, in men, serum urate levels were significantly lower in the synucleinopathy group compared with the tauopathy group (P = 0.046), although with a broad overlap. CONCLUSION: Our study suggests that urate levels might provide new insights into the potential pathophysiological mechanisms underlying Parkinsonism and thereby contribute to the future management of these disorders.
