Emerging roles of circular RNAs and enhancer RNAs: new insights into the development and management of neurodegenerative disorders

Neurodegenerative disorders involve the gradual breakdown of neurons, leading to problems with thinking, movement, and mental health. More evidence is emerging about the important roles of non-coding RNAs (ncRNAs). CircRNAs are a type of ncRNA formed through back-splicing and are widely present in the mammalian brain. They play crucial roles in brain development and mainly regulate gene expression and post-transcriptional processes by acting as molecular sponges for miRNAs and RBPs. eRNAs are another class of ncRNAs. They are produced from enhancer regions of the genome and act as vital regulatory elements in gene expression. There is increasing evidence that abnormal levels of circRNAs and eRNAs can be found in many human diseases, including neurodegenerative conditions. This suggests they could have important clinical uses in these illnesses. The unique stability and disease-specific expression patterns of circRNAs and eRNAs in biofluids like blood and cerebrospinal fluid make them strong candidates for noninvasive biomarkers in neurodegenerative disorders, such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and multiple sclerosis. Additionally, their roles in crucial pathological pathways open new opportunities for treatment. This includes strategies that target RNA, such as antisense oligonucleotides or miRNA sponges, to influence gene expression networks. This review gathers recent findings to propose that circRNAs and eRNAs might introduce a new layer of regulation in neurodegeneration, providing exciting possibilities for real-world applications.