Related Experiment Video
Updated: Jul 15, 2025
Identification of Circular RNAs using RNA Sequencing
Published on: November 14, 2019
A new perspective on Alzheimer's disease: microRNAs and circular RNAs
Shahidee Zainal Abidin1,2, Nurul Asykin Mat Pauzi1, Nur Izzati Mansor3
1Faculty of Science and Marine Environment, Universiti Malaysia Terengganu, Terengganu, Malaysia.
Abstract:
microRNAs (miRNAs) play a multifaceted role in the pathogenesis of Alzheimer's disease (AD). miRNAs regulate several aspects of the disease, such as Aβ metabolism, tau phosphorylation, neuroinflammation, and synaptic function. The dynamic interaction between miRNAs and their target genes depends upon various factors, including the subcellular localization of miRNAs, the relative abundance of miRNAs and target mRNAs, and the affinity of miRNA-mRNA interactions. The miRNAs are released into extracellular fluids and subsequently conveyed to specific target cells through various modes of transportation, such as exosomes. In comparison, circular RNAs (circRNAs) are non-coding RNA (ncRNA) characterized by their covalently closed continuous loops. In contrast to linear RNA, RNA molecules are circularized by forming covalent bonds between the 3'and 5'ends. CircRNA regulates gene expression through interaction with miRNAs at either the transcriptional or post-transcriptional level, even though their precise functions and mechanisms of gene regulation remain to be elucidated. The current stage of research on miRNA expression profiles for diagnostic purposes in complex disorders such as Alzheimer's disease is still in its early phase, primarily due to the intricate nature of the underlying pathological causes, which encompass a diverse range of pathways and targets. Hence, this review comprehensively addressed the alteration of miRNA expression across diverse sources such as peripheral blood, exosome, cerebrospinal fluid, and brain in AD patients. This review also addresses the nascent involvement of circRNAs in the pathogenesis of AD and their prospective utility as biomarkers and therapeutic targets for these conditions in future research.
Insights
MicroRNAs (miRNAs) and circular RNAs (circRNAs) are implicated in Alzheimer's disease (AD) pathogenesis. This review examines altered miRNA expression in AD patients and the emerging role of circRNAs as potential biomarkers and therapeutic targets.
Area of Science:
- Neuroscience
- Molecular Biology
- Genetics
Background:
- MicroRNAs (miRNAs) are key regulators in Alzheimer's disease (AD) pathogenesis, influencing Aβ metabolism, tau phosphorylation, neuroinflammation, and synaptic function.
- miRNA activity is modulated by factors like subcellular localization, miRNA-mRNA abundance, and binding affinity, with extracellular miRNAs transported via exosomes.
- Circular RNAs (circRNAs), a novel class of non-coding RNAs, regulate gene expression via interactions with miRNAs, though their precise mechanisms in AD are under investigation.
Purpose of the Study:
- To comprehensively review alterations in miRNA expression across various sources (blood, exosomes, CSF, brain) in Alzheimer's disease (AD) patients.
- To explore the emerging role of circular RNAs (circRNAs) in the pathogenesis of AD.
- To discuss the potential of miRNAs and circRNAs as diagnostic biomarkers and therapeutic targets for AD.
Main Methods:
- Literature review of studies investigating miRNA expression profiles in Alzheimer's disease.
- Analysis of research on the involvement of circular RNAs in AD pathology.
- Synthesis of current understanding of miRNA and circRNA functions and interactions in neurodegenerative diseases.
Main Results:
- Significant alterations in miRNA expression are observed in peripheral blood, exosomes, cerebrospinal fluid, and brain tissue of AD patients.
- Emerging evidence suggests circRNAs play a role in AD pathogenesis, potentially through interactions with miRNAs.
- The complexity of AD pathology presents challenges for miRNA-based diagnostics, necessitating further research.
Conclusions:
- miRNAs are critical players in AD, with altered expression patterns offering diagnostic potential across different biological fluids and tissues.
- circRNAs represent a promising area of research for understanding AD mechanisms and developing novel therapeutic strategies.
- Further investigation into miRNA and circRNA profiles is essential for advancing AD diagnostics and therapeutics.
Related Concept Videos
01:22MicroRNAs
01:26Alzheimer's Disease: Overview
The clinical diagnosis of AD hinges on the presence of memory and other cognitive impairments. Biomarkers, such as changes in Aβ...
02:30siRNA - Small Interfering RNAs
In the cytoplasm, siRNA is processed from a double-stranded RNA, which comes from either endogenous DNA transcription or exogenous sources like a virus. This double-stranded RNA is then cleaved by the...
01:22Alzheimer's Disease: Treatment
01:23RNA Interference
This process occurs naturally in cells, often through the activity of genomically-encoded microRNAs. Researchers can take advantage of this mechanism by introducing synthetic RNAs to deactivate specific genes for research or therapeutic purposes. For example, RNAi could be used...
02:15Experimental RNAi