Micro RNA as a potential blood-based epigenetic biomarker for Alzheimer's disease

Peter D Fransquet1, Joanne Ryan2

  • 1Department of Epidemiology and Preventive Medicine, Monash University, Melbourne 3004, Victoria, Australia; Disease Epigenetics, Murdoch Childrens Research Institute, and The University of Melbourne, Parkville, 3052, Victoria, Australia.

Clinical Biochemistry
|June 10, 2018
PubMed

Insights

MicroRNAs (miRNAs) show promise as Alzheimer

Area of Science:

  • Neuroscience
  • Genetics
  • Biomarker Discovery

Background:

  • Alzheimer's disease (AD) prevalence is rising, increasing the need for accessible diagnostic biomarkers.
  • MicroRNAs (miRNAs) are epigenetic regulators of protein synthesis, with expression levels potentially varying in disease states like AD.
  • Blood-based miRNA measurements are explored as a less invasive diagnostic approach compared to traditional methods.

Purpose of the Study:

  • To comprehensively review existing studies on miRNA measurement in blood for Alzheimer's disease diagnosis.
  • To identify specific miRNAs consistently found to be differentially expressed in AD cases versus controls.
  • To assess the diagnostic accuracy and reliability of blood-based miRNAs as Alzheimer's biomarkers.

Main Methods:

  • Systematic review and meta-analysis of 26 studies comparing blood miRNA levels in AD patients and healthy controls.
  • Analysis of diagnostic accuracy using receiver operator characteristic (ROC) analysis and machine learning approaches.
  • Identification of differentially expressed miRNAs across studies and assessment of expression consistency and direction.

Main Results:

  • Out of 8098 measured miRNAs, 23 were significantly different between AD cases and controls in two or more studies.
  • Six miRNAs (miR-107, miR-125b, miR-146a, miR-181c, miR-29b, miR-342) showed consistent downregulation in AD patients across studies.
  • miR-107 demonstrated the strongest evidence, with prior links to AD pathology and consistent downregulation in both blood and brain studies.

Conclusions:

  • Specific miRNAs, particularly miR-107, show potential as blood-based biomarkers for Alzheimer's disease.
  • Standardized measurement methods, robust statistical analysis, and machine learning are crucial for developing reliable miRNA biomarkers.
  • Further research with large datasets and comprehensive reporting is needed to validate these findings and translate them into clinical practice.