miRNAs: Current and future diagnostic biomarkers in liver fibrosis

Liver fibrosis is an abnormal response of the liver to various pathogenic factors. It represents a critical stage in the progression from chronic liver disease to cirrhosis and liver cancer. Without timely diagnosis and intervention, liver fibrosis can significantly reduce patients' survival rates and quality of life. In liver fibrosis, microRNA (miRNA) plays a dual role in disease progression by regulating gene expression and signaling pathways. Some miRNAs have antifibrotic effects by inhibiting the TGF-β/Smad signaling pathway or blocking the activation of hepatic stellate cells (HSCs). In contrast, other miRNAs accelerate fibrosis by activating the HIF-1α/VEGF pathway or promoting abnormal extracellular matrix deposition. This two-way relationship establishes a basis for investigating miRNAs as potential diagnostic markers. This narrative review synthesizes evidence on various miRNAs associated with liver fibrosis and their molecular mechanisms. It also evaluates their potential applications in serological testing. Research shows that miRNAs, because of their high stability and specificity, are likely to overcome the limitations of traditional methods for diagnosing liver fibrosis. Furthermore, this article evaluates the strengths and weaknesses of popular miRNA detection methods, such as real-time quantitative PCR, microarrays, and next-generation sequencing (NGS), emphasizing that optimizing standardized processes and high-throughput technologies is essential for facilitating the clinical use of miRNAs. In summary, miRNAs are promising non-invasive diagnostic tools for the early diagnosis and personalized treatment of liver fibrosis. Nonetheless, additional research is essential to improve the technology and clinical validation of miRNA detection for its widespread use in clinical settings.