RNA delivery by extracellular vesicles in mammalian cells and its applications.

The term 'extracellular vesicles' refers to a heterogeneous population of vesicular bodies of cellular origin that derive either from the endosomal compartment (exosomes) or as a result of shedding from the plasma membrane (microvesicles, oncosomes and apoptotic bodies). Extracellular vesicles carry a variety of cargo, including RNAs, proteins, lipids and DNA, which can be taken up by other cells, both in the direct vicinity of the source cell and at distant sites in the body via biofluids, and elicit a variety of phenotypic responses. Owing to their unique biology and roles in cell-cell communication, extracellular vesicles have attracted strong interest, which is further enhanced by their potential clinical utility. Because extracellular vesicles derive their cargo from the contents of the cells that produce them, they are attractive sources of biomarkers for a variety of diseases. Furthermore, studies demonstrating phenotypic effects of specific extracellular vesicle-associated cargo on target cells have stoked interest in extracellular vesicles as therapeutic vehicles. There is particularly strong evidence that the RNA cargo of extracellular vesicles can alter recipient cell gene expression and function. During the past decade, extracellular vesicles and their RNA cargo have become better defined, but many aspects of extracellular vesicle biology remain to be elucidated. These include selective cargo loading resulting in substantial differences between the composition of extracellular vesicles and source cells; heterogeneity in extracellular vesicle size and composition; and undefined mechanisms for the uptake of extracellular vesicles into recipient cells and the fates of their cargo. Further progress in unravelling the basic mechanisms of extracellular vesicle biogenesis, transport, and cargo delivery and function is needed for successful clinical implementation. This Review focuses on the current state of knowledge pertaining to packaging, transport and function of RNAs in extracellular vesicles and outlines the progress made thus far towards their clinical applications

Onset and recovery of physiological stress in Liocarcinus depurator trawled and subjected to air emersion under different seasonal temperature regimes.

The onset of and recovery from physiological stress in Liocarcinus depurator (Decapoda: Portunidae), that were trawled and subjected to emersion during fishing activities, was analysed in a field study in the Northern Adriatic Sea. Our working hypothesis intended to assess the development of physiological impairment due to air exposure during sorting operations, and the possible recovery trajectories after the return to sea of this by-caught species. The protocol we used included experimental trawling and quantification of physiological stress indicators (haemolymph concentrations of L-lactate, D-glucose, ammonia and pH) under different seasonal conditions. Immediately after being caught, when the fishing net was emptied on board, L. depurator showed higher physiological imbalance in the summer vs. winter experiments, highlighting the immediate effect of temperature shock due to the difference in temperature between the sea bottom and the deck (15-18 and 2 degrees C in summer and winter, respectively). Experimental animals in the permanently emersed condition exhibited a progressive disruption of homeostasis in both seasons, as confirmed by a significant increase in lactate and a decrease in the pH of the haemolymph as a function of the emersion time. Ammonia levels were almost stable in the summer, when the physiological limits of this metabolite were reached immediately after animals were caught. In the winter, a significant increase in ammonia was observed over the time. This pattern can be attributed to the impairment of gill function, resulting in suffocation (manifested by marked haemolymph acidosis) and reduced ammonia excretion. Glucose concentration was revealed to be stable during air exposure in both seasons, though a higher concentration was recorded in the summer compared to the winter. The recovered individuals tended to return to pre-caught values for all of the haemolymph parameters we measured, though with different trajectories in the two seasons. From these results, we conclude that temperature shock, coupled with air exposure, influenced the ultimate stress level of this species to a greater extent than other effects of fishing