Exosomes

Part of speech: noun

Definitions

1. Small membrane-bound vesicles released by cells that transport proteins, lipids, and genetic material between cells for communication and signaling ; Extracellular nanovesicles originating from endosomal compartments that carry molecular cargo to influence recipient cell function ; Tiny cellular particles secreted into bodily fluids that facilitate intercellular communication by transferring bioactive molecules among cells
2. Minute vesicular structures secreted by various cell types to mediate transfer of RNA, proteins, and lipids between cells, thus playing roles in cellular communication and immune response ; Cell-derived vesicles formed within multivesicular bodies and released into the extracellular space, involved in modulation of recipient cell behavior through delivery of molecular signals ; Nanometer-sized extracellular vesicles produced in the endosomal network, serving as vehicles for molecules that regulate physiological and pathological processes in adjacent or distant cells
3. Lipid bilayer-enclosed particles produced intracellularly and released to transmit diverse biological messages through encapsulated molecules ; Membrane vesicles generated inside cells and secreted into the extracellular environment, carrying functional biomolecules that enable cell-to-cell interaction and systemic signaling ; Small extracellular vesicles formed by the inward budding of endosomal membranes, involved in transferring proteins and nucleic acids to target cells to influence their activities

Etymology: The term "exosomes" emerged in the mid-20th century within the realm of cellular biology, following advances in microscopy and biochemical techniques that allowed scientists to observe tiny vesicles released from cells. These small membrane-bound particles were initially discovered as a means by which cells discard unwanted materials. The distinctive feature of these vesicles was their origin from intracellular compartments called multivesicular bodies, which fuse with the cell membrane to release their contents outside the cell. The word itself is formed from the Greek prefix "exo-" meaning "outside" or "external," combined with "some," derived from the Greek "soma," meaning "body." This composition reflects the nature of these vesicles as small "bodies" that exit the cell, highlighting their extracellular release. The suffix "-some" is common in biology to denote bodies or particles, as seen in words like "lysosome" or "ribosome." Interest in these structures expanded significantly in the late 20th and early 21st centuries when researchers found that exosomes carry not only waste but also important signaling molecules, such as proteins and RNA, between cells. This function revealed their role in intercellular communication and their potential implications in health and disease, including cancer, immune responses, and neurodegenerative disorders. Thus, the term encapsulates both the physical characteristic of these vesicles as small bodies that exit the cell and their functional significance in cellular communication, a meaning that has evolved alongside scientific understanding since their initial discovery.

Synonyms: extracellular vesicles