Small extracellular vesicles and liver diseases: From diagnosis to therapy

Inflammatory macrophage to hepatocyte signals can be prevented by extracellular vesicle reprogramming

Macrophage-derived extracellular vesicles (EVs) play key roles in intercellular communication. Within the liver, they have been linked to several inflammatory diseases including nonalcoholic fatty liver disease (NAFLD). In this study, we found that inflammatory macrophages cause injury to hepatocytes, in part by a cell-cell crosstalk phenomenon involving the secretion of EVs containing pro-inflammatory cargo. Incorporation of these inflammatory signals into EV requires the cleavage of the trafficking adaptor protein RILP, which, as previously shown, results from inflammasome-mediated caspase-1 activation. RILP cleavage can be blocked by overexpressing a dominant negative, non-cleavable form of RILP (ncRILP). EV preparations from ncRILP-expressing cells are, by themselves, sufficient to suppress inflammatory effects in hepatocytes. These results suggest that both direct RILP manipulation and/or supplying ncRILP-modified EVs could be used as a novel therapy for the treatment of inflammatory liver diseases.

An Insight into the Arising Role of MicroRNAs in Hepatocellular Carcinoma: Future Diagnostic and Therapeutic Approaches

Hepatocellular carcinoma (HCC) constitutes a frequent highly malignant form of primary liver cancer and is the third cause of death attributable to malignancy. Despite the improvement in the therapeutic strategies with the exploration of novel pharmacological agents, the survival rate for HCC is still low. Shedding light on the multiplex genetic and epigenetic background of HCC, such as on the emerging role of microRNAs, is considered quite promising for the diagnosis and the prediction of this malignancy, as well as for combatting drug resistance. MicroRNAs (miRNAs) constitute small noncoding RNA sequences, which play a key role in the regulation of several signaling and metabolic pathways, as well as of pivotal cellular functions such as autophagy, apoptosis, and cell proliferation. It is also demonstrated that miRNAs are significantly implicated in carcinogenesis, either acting as tumor suppressors or oncomiRs, while aberrations in their expression levels are closely associated with tumor growth and progression, as well as with local invasion and metastatic dissemination. The arising role of miRNAs in HCC is in the spotlight of the current scientific research, aiming at the development of novel therapeutic perspectives. In this review, we will shed light on the emerging role of miRNAs in HCC.