Exosomes: scytales in the damaged heart

As cells in our organism are constantly sending out and receiving signals, cell-cell communication is an essential way to maintain process homeostasis while allowing adaptation to external stimuli. Disturbances in cell-to-cell communication will result in disease. Cells communicate with each other via extracellular molecules such as nucleotides, short peptides, proteins or lipids that are released to the extracellular space and bind receptors on other cells, therefore inducing signaling and modifying the molecular status of the recipient cells. In addition to such molecules, cells also release membrane vesicles, representing a rich source of small molecules such as messenger RNAs, microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), small amounts of DNA and low molecular weight lipids and proteins (including transcription factors and cytokines), all of which can also alter recipient cells that encounter such structures. Although initially thought as cellular debris and a sign of cellular death, in recent years more interest has been dedicated to extracellular vesicles (EVs) as mediators of long-range cellular communication by their presence in most body fluids.