Qualitative and quantitative characterization of exosomes secreted by rat hepatocytes

Exosomes are nanometer-sized vesicles (30-150 nm) that form multivesicular bodies (MVBs) by means of inward budding of the limiting membrane. Upon fusion of the MVBs with the plasma membrane, exosomes are released to the extracellular medium, where they have been shown to play different roles in cell-to-cell communication functions, such as antigen presentation or induction of antitumor responses. Given the specific tissue signatures, exosomes might harbour diagnostic markers. Two well-known cytotoxic compounds, namely galactosamine and lypopolisaccharide, have been chosen to discern diagnostic markers of hepatic diseases in the exosomal proteome. In this study, we have characterized at the protein expression, microscopic and molecular level, exosomes secreted from primary cultured rat hepatocytes treated and untreated with these hepatotoxic agents.