Background: Alcohol-associated Liver Disease (ALD) is the most common disorder of prolonged drinking. Mechanisms underlying cirrhosis in such patients remain unclear. MicroRNAs play regulatory role in several diseases, are affected by alcohol and may be important players in alcohol use disorders, such as cirrhosis.
Methods: We investigated serum samples from heavy chronic alcohol users (80g/d (M) and 50g/d (F) for ≥10 years) that were available from our previously reported GenomALC study. A subset of drinkers with liver cirrhosis (cases, n=24) and those without significant liver disease (controls, n=23) were included. Healthy controls (HC, n=5) were volunteers in the study. Global microRNA profiling was performed using high-throughput real-time quantitative PCR to identify the microRNA signatures. Ingenuity Pathway Analysis software (IPA) was utilized to identify target mRNAs of significantly altered microRNAs and molecular pathways were analysed. Identified microRNAs were analysed for correlation with traditional liver disease biomarkers and risk gene variants previously reported from GenomALC genome-wide association study.
Results: The expression of 81 and 21 microRNAs was significantly downregulated in cases compared to HC and controls, respectively (p<0.05, Ct >1.5-fold). Most microRNAs showed lower abundance in alcohol users compared with HC. Seven microRNAs (miR-16, miR-19a, miR-27a, miR-29b, miR-101, miR-130a, & miR-191) had a highly significant correlation (p<0.001) with INR, bilirubin and MELD score. Three microRNAs (miR-27a, miR-130a and miR-191) significantly predicted cases with AUC-ROC 0.8, 0.78 and 0.85, respectively (P<0.020), however, INR performed best (0.97, p<0.001). A different set of 6 microRNAs (miR-19a, miR-26a, miR-101, miR-151-3p, miR-221, & miR-301) showed positive correlation (ranging 0.32-0.51, p<0.05) with rs10433937:HSD17B13 gene variant, associated with risk of cirrhosis. IPA analysis revealed mRNA targets of the significantly altered microRNAs associated with cell death/necrosis, fibrosis and increased steatosis, particularly triglyceride metabolism related mRNA targets.
Conclusions: MicroRNA signatures in drinkers distinguished those with liver cirrhosis from those without liver disease. We identified mRNA targets in liver functions that were enriched for disease pathogenesis pathways.