Circulating Extracellular Vesicles as Liver Biomarkers

Abstract

Extracellular vesicles (EV) released by various types of cells are detectable in body fluids such as blood and urine. Both clinical and animal studies showed that circulating EVs were elevated in response to many types of liver diseases, such as hepatocellular carcinoma (HCC), nonalcoholic fatty liver disease, acute liver failure, liver cirrhosis, hepatic ischemia-reperfusion (I/R) injury, and drug-induced liver injury. The increase in subgroups of EVs and certain EV molecules was found to be of diagnostic and prognostic value for some liver diseases such as HCC and liver cirrhosis. Some microRNA species were solely increased in serum EVs but not the whole serum under disease states, indicating that circulating EVs may provide more sensitive liver biomarkers. Blood EVs from patients appeared to play a detrimental role contributing disease progression. Blocking blood EV elevation by pharmacological approaches afforded protection against liver damage. Circulating EVs are emerging as a rich source of new biomarkers for liver diseases.