Extracellular Vesicles in Kidney Diseases: Moving Forward.

Extracellular vesicles (EVs) are evolving as novel cell mediators, biomarkers, and therapeutic targets in kidney health and disease. They are naturally derived from cells both within and outside the kidney and carry cargo which mirrors the state of the parent cell. Thus, they are potentially more sensitive and disease-specific as biomarkers and messengers in various kidney diseases. Beside their role as novel communicators within the nephron, they likely communicate between different organs affected by various kidney diseases. Study of urinary EVs (uEVs) can help to fill current knowledge gaps in kidney diseases. However, separation and characterization are challenged by their heterogeneity in size, shape, and cargo. Fortunately, more sensitive and direct EV measuring tools are in development. Many clinical syndromes in nephrology from acute to chronic kidney and glomerular to tubular diseases have been studied. Yet, validation of biomarkers in larger cohorts is warranted and simpler tools are needed. Translation from in vitro to in vivo studies is also urgently needed. The therapeutic role of uEVs in kidney diseases has been studied extensively in rodent models of AKI. On the basis of the current exponential growth of EV research, the field of EV diagnostics and therapeutics is moving forward.