Extracellular vesicles as regulators of kidney function and disease

Extracellular vesicles (EVs) are small, lipid bilayer-delimited particles of cellular origin that recently gained increasing attention for their potential use as diagnostic biomarkers, and beyond that for their role in intercellular communication and as regulators of homeostatic and disease processes. In acute kidney injury (AKI) and chronic kidney disease (CKD), the potential use of EVs as diagnostic and prognostic markers has been evaluated in a series of clinical studies and contributions to pathophysiologic pathways have been investigated in experimental models. While EV concentrations in biofluids could not distinguish renal patients from healthy subjects or determine disease progression, specific EV subpopulations have been identified that may provide useful diagnostic and prognostic tools in AKI. Specific EV subpopulations are also associated with clinical complications in sepsis-induced AKI and in CKD. Beyond their role as biomarkers, pathophysiologic involvement of EVs has been shown in hemolytic uremic syndrome- and sepsis-induced AKI as well as in cardiovascular complications of CKD. On the other hand, some endogenously formed or therapeutically applied EVs demonstrate protective effects pointing toward their usefulness as emerging treatment strategy in kidney disease.