Circulating miRNAs associated with nonalcoholic fatty liver disease

Area of Science:

• Molecular Biology
• Hepatology
• Biomarker Discovery

Background:

• Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) lack reliable noninvasive diagnostic methods, necessitating costly and invasive liver biopsies.
• Circulating microRNAs (miRNAs), secreted by liver cells, are potential biomarkers due to their modifiability by metabolic treatments.
• Identifying specific circulating miRNAs associated with NAFLD/NASH can improve diagnosis, monitoring, and prognosis.

Purpose of the Study:

• To review the mechanisms of RNA secretion and the potential of circulating RNAs, particularly miRNAs, as biomarkers for NAFLD and NASH.
• To summarize the current evidence for specific circulating miRNAs associated with NAFLD and NASH.

Main Methods:

• Literature review summarizing the mechanisms of miRNA secretion.
• Analysis of published studies identifying circulating miRNAs associated with NAFLD and NASH.
• Evaluation of the biomarker potential of consistently reported circulating miRNAs.

Main Results:

• Key circulating miRNAs consistently associated with NAFLD/NASH include miR-122, miR-21, miR-34a, miR-192, miR-193, and the miR-17-92 cluster.
• Hepatocyte-enriched miR-122 is increased in NAFLD/NASH but decreased in cirrhosis.
• miR-34a and miR-21 are consistently elevated in NAFLD/NASH; miR-192 shows higher upregulation in NASH, and miR-193 may distinguish NASH from fibrosis.

Conclusions:

• Circulating miRNAs demonstrate significant potential as noninvasive biomarkers for fatty liver disease diagnosis and monitoring.
• Specific miRNAs like miR-122, miR-21, miR-34a, miR-192, and miR-193 show promise, but require further validation.
• Additional research is essential to determine phenotype specificity and longitudinal regulation of these miRNA biomarkers for clinical application.