The promise of small particles: extracellular vesicles as biomarkers in liver pathology

The role of macrophage-derived exosomes in noncancer liver diseases: From intercellular crosstalk to clinical potential

Chronic liver disease has a substantial global prevalence and mortality rate. Macrophages, pivotal cells in innate immunity, exhibit remarkable heterogeneity and plasticity and play a considerable role in maintaining organ homeostasis, modulating inflammatory responses, and influencing disease progression in the liver. Exosomes, which can serve as conduits for intercellular communication, biomarkers, and therapeutic targets for a spectrum of diseases, have recently garnered increasing attention recently. Given that the liver is the organ with the highest macrophage content, a thorough understanding of the influence of macrophage-derived exosomes (MDEs) on noncancer liver disease pathogenesis and their potential therapeutic applications is paramount. Interactions among MDEs, hepatocytes, hepatic stellate cells (HSCs), and other nonparenchymal cells constitute a complex network regulates liver immune homeostasis. In this review, we summarize the latest progress in the current understanding of MDE heterogeneity and cellular crosstalk in noncancer liver diseases, as well as their potential clinical applications. Additionally, challenges and future directions are underscored.

Current updates on the molecular and genetic signals as diagnostic and therapeutic targets for hepatitis B virus-associated hepatic malignancy

Liver cancer caused by the hepatitis B virus (HBV) is the third most common cancer-related cause of death worldwide. Early detection of HBV-caused hepatic tumors increases the likelihood of a successful cure. Molecular and genetic signals are becoming more and more recognized as possible indicators of HBV-associated hepatic malignancy and of how well a treatment is working. As a result, we have discussed the current literature on molecular and genetic sensors, including extracellular vesicle microRNAs (EV-miRNAs), long non-coding circulating RNAs (lncRNAs), extracellular vesicles (EVs), and cell free circulating DNA (cfDNA), for the diagnosis and forecasting of HBV-related hepatic cancer. Extracellular vesicle microRNAs such as miR-335-5p, miR-172-5p, miR-1285-5p, miR-497-5p, miR-636, miR-187-5p, miR-223-3p, miR-21, miR-324-3p, miR-210-3p, miR-718, miR-122, miR-522, miR-0308-3p, and miR-375 are essential for the posttranscriptional regulation of oncogenes in hepatic cells as well as the epigenetic modulation of many internal and external signaling pathways in HBV-induced hepatic carcinogenesis. LncRNAs like lnc01977, HULC (highly up-regulated in liver cancer), MALAT1 (metastasis-associated lung adenocarcinoma transcript 1), and HOTAIR (hox transcript antisense intergenic RNA) have been demonstrated to control hepatic-tumors cell growth, relocation, encroachment, and cell death resiliency. They are also becoming more and more involved in immune tracking, hepatic shifting, vasculature oversight, and genomic destabilization. EVs are critical mediators involved in multiple aspects of liver-tumors like angiogenesis, immunology, tumor formation, and the dissemination of malignant hepatocytes. Furthermore, cfDNA contributes to signals associated with tumors, including mutations and abnormal epigenetic changes during HBV-related hepatic tumorigenesis.

Extracellular Vesicles and Their Correlation with Inflammatory Factors in an Experimental Model of Steatotic Liver Disease Associated with Metabolic Dysfunction

Background/Aims: Extracellular vesicles (EVs) are promising as a biomarker of metabolic dysfunction associated steatotic liver disease (MASLD). The objective is to study EVs and their involvement in MASLD concerning the disease's pathogenesis and progression characteristics. Methods: Male adult Sprague Dawley rats were randomly assigned into two experimental models of MASLD: MASLD-16 and MASLD-28, animals received a choline-deficient high-fat diet (CHFD) and Control-16 and Control-28, animals received a standard diet (SD) for 16 and 28 weeks, respectively. Biological samples from these animal models were used, as well as previously registered variables. EVs from hepatic tissue were characterized using confocal microscopy. EVs were isolated through differential ultracentrifugation from serum and characterized using NanoSight. The data from the EVs were correlated with biochemical, molecular, and histopathological parameters. Results: Liver EVs were identified through the flotillin-1 protein. EVs were isolated from the serum of all groups. There was a decrease of EVs concentration in MASLD-28 in comparison with Control-28 (P < 0.001) and a significant increase in EVs concentration in Control-28 compared with Control-16 (P < 0.001). There was a strong correlation between serum EVs concentration with hepatic gene expression of interleukin (Il)6 (r2 = 0.685, P < 0.05), Il1b (r2 = 0.697, P < 0.05) and tumor necrosis factor-alpha (Tnfa; r2 = 0.636, P < 0.05) in MASLD-16. Moreover, there was a strong correlation between serum EVs size and Il10 in MASLD-28 (r2 = 0.762, P < 0.05). Conclusion: The concentration and size of EVs correlated with inflammatory markers, suggesting their involvement in the systemic circulation, cellular communication, and development and progression of MASLD, demonstrating that EVs have the potential to serve as noninvasive biomarkers for MASLD diagnosis and prognosis.

Regulation of Extracellular Vesicle-Mediated Immune Responses against Antigen-Specific Presentation

Extracellular vesicles (EVs) produced by various immune cells, including B and T cells, macrophages, dendritic cells (DCs), natural killer (NK) cells, and mast cells, mediate intercellular communication and have attracted much attention owing to the novel delivery system of molecules in vivo. DCs are among the most active exosome-secreting cells of the immune system. EVs produced by cancer cells contain cancer antigens; therefore, the development of vaccine therapy that does not require the identification of cancer antigens using cancer-cell-derived EVs may have significant clinical implications. In this review, we summarise the molecular mechanisms underlying EV-based immune responses and their therapeutic effects on tumour vaccination.