The Role of MicroRNA in the Pathogenesis and Diagnostics of Parkinson’s Disease

Abstract

Abstract—Lately the investigation of non-coding RNAs that play an important role in epigenetic regulation of gene expression, along with the methylation of DNA and modification of histones, has begun. MicroRNAs of 19–24 nucleotides in length are the most studied class. Currently over 5000 various microRNAs have been identified in the human epigenome, and that number is constantly increasing. MicroRNAs are capable of specific binding to the 3’ end of complementary messenger RNA, which induces its degradation and therefore gene silencing. In this review, the role of microRNAs in the pathogenesis of Parkinson’s disease (PD) is discussed, as well as the possibility of using them as diagnostic markers of the disease. The results of different studies of microRNA in various brain regions, blood, and cerebrospinal fluid of patients with PD are presented. Several articles have reported the influence of microRNA on the functioning of genes responsible for monogenic types of PD. However, the majority of microRNAs are not associated with the monogenic forms and their functions are still undetermined. Several studies have demonstrated an increase in miR-195 and miR-24 microRNAs and a decrease in miR-29c, miR-30c, miR-146a-5p, miR-185, miR-19b, miR-214, and miR-222 in PD. A number of studies have proposed panels including several microRNAs, determination of which allows PD diagnosis with high accuracy. MicroRNAs that are changed during treatment with medications for Parkinson’s disease or deep brain stimulation have been described. Some microRNAs may be applied for differential diagnostics with other parkinsonian syndromes, particularly multiple system atrophy. Additionally, researchers have attempted to unite the identified changes into functional networks of microRNAs characterizing the disease. Induced pluripotent stem cells of patients with PD are used as an experimental model of the disease, allowing the role of the processes involving microRNAs in PD development to be estimated. Although microRNAs are scantily studied, it is already clear that non-coding RNAs are essential in the pathogenesis of neurodegenerative diseases and promising results in this field may lay the foundation for an epigenetic approach to the treatment of PD.