Linear and circular RNAs for the detection and treatment of Parkinson's disease

Parkinson’s disease is the second most common neurodegenerative disorder worldwide and to date there are no cure or disease modifying therapies available. In addition to this there is an unmet need for more efficient and accurate diagnostic tools. This leads to the necessity of finding biomarkers able to detect the disease earlier and the research in this field is highlighting the role of RNAs to fulfill this purpose. The focus of this project stems from previously obtained data regarding the role of a circular RNA, henceforth referred to as circRNA1, in cardiac arrest. This RNA has been identified as a possible biomarker for these patients and was associated with poor neurological outcome. These findings raised the hypothesis that this circular RNA could be involved in further neurological or neurodegenerative disorders. As such, the objective of this thesis was to uncover the role of circRNA1 and the linear RNA1 (also renamed due to intellectual property rights) in Parkinson’s disease (PD). Using a previously established in-vitro model of PD, a series of experiments were carried out to evaluate whether RNA1 and circRNA1 are modulated in PD, whether they could be used as biomarkers and/or therapeutic targets and whether their expression changes following treatment using a widely used PD drug, Levodopa. SH-SY5Y cells, a neuroblastoma cell line, were the model used in this project and MPP, a neurotoxin, was used to cause mitochondrial dysfunction, similar to that observed in PD patients. The main experiments performed included functional studies through downregulation of the RNAs, RNA-RNA pulldown to evaluate the relationship with known genes/pathways of PD and experiments of differentiation to neurons followed by treatment with Levodopa to evaluate the effects of the drug on the selected RNAs. In addition to this, quantitative PCR for RNA1 and circRNA1 in whole blood samples of a cohort of idiopathic PD patients and control samples was performed to evaluate the potential of those RNAs as biomarkers. The result obtained through the sum of the various experiments gives an overview of the expression of these two RNAs in Parkinson’s Disease that represents the starting point to evaluate in the future their actual role in the pathways involved in the disease.