MicroRNAs and synaptic dysfunction in Parkinson's disease

Parkinson's disease (PD) is a debilitating neurodegenerative condition. Synaptic dysfunctions are associated with the onset and progressive neurodegeneration exhibited in PD. Healthy, active synapses are a prerequisite for non-pathological neurotransmission. When neurotransmission becomes pathological, such as observed in neurodegenerative conditions like PD, the biomolecules found in and around such synapses need distinctive investigation. MicroRNAs (miRNAs) found in neuronal subcellular compartments, such as dendrites, pre-synaptic boutons, and synaptic vesicles, have been garnering attention in neurogenerative diseases. MiRNAs that modulate synaptic activity and synapse function are called synaptic miRNAs. Several miRNAs have been identified that regulate key synaptic proteins; however, information about synaptic miRNAs is largely unknown in PD. In this review, we focused on the most promising synaptic miRNAs, those that are critical for normal synapse function and play a crucial role in PD pathology. We also discussed the synaptic miRNA's interplay with PD-associated synaptic dysfunction. Investigating further how synaptic miRNAs impacts PD pathogenesis may uncover novel etiological information and potential pathways for treatments and a cure for PD.