Extracellular vesicles

Definition

Extracellular vesicles (EVs) are small, membrane-bound particles released from cells into the extracellular space, playing a vital role in intercellular communication. They are involved in various biological processes, including immune response, cell signaling, and the transfer of biomolecules like proteins, lipids, and RNA between cells. EVs can be classified into subtypes such as exosomes and microvesicles, each with distinct origins and functions.

5 Must Know Facts For Your Next Test

1. Extracellular vesicles can carry diverse cargo, including proteins, lipids, mRNA, and microRNA, which can influence the behavior of recipient cells.
2. The biogenesis of EVs occurs through different pathways; exosomes are formed within multivesicular bodies while microvesicles arise from direct budding off the plasma membrane.
3. Extracellular vesicles are being investigated as potential tools for drug delivery due to their ability to transport therapeutic agents to targeted cells.
4. EVs have been shown to play important roles in cancer progression by facilitating tumor growth, metastasis, and immune evasion.
5. Analytical techniques like nanoparticle tracking analysis (NTA) allow for the characterization and quantification of EVs based on their size and concentration in biological samples.

Review Questions

• How do extracellular vesicles contribute to intercellular communication and what types of molecules do they transport?
  • Extracellular vesicles facilitate intercellular communication by transporting various biomolecules between cells. They carry proteins, lipids, mRNA, and microRNA that can alter the behavior of recipient cells upon uptake. This transport mechanism allows cells to send signals and share genetic information, influencing processes like immune responses, tissue repair, and even tumor progression.
• Discuss the differences between exosomes and microvesicles in terms of their biogenesis and function.
  • Exosomes and microvesicles differ primarily in their size and biogenesis. Exosomes are smaller (30-150 nm) and originate from the inward budding of multivesicular bodies before being released when these bodies fuse with the plasma membrane. Microvesicles are larger (100 nm to 1 µm) and form directly from the outward budding of the plasma membrane. Functionally, both types play roles in cell signaling but may differ in their specific cargo composition and the types of recipient cells they interact with.
• Evaluate the potential of extracellular vesicles as biomarkers for disease diagnosis and treatment monitoring.
  • Extracellular vesicles hold significant potential as biomarkers due to their ability to reflect the physiological state of their parent cells. Their cargo can provide insights into disease processes, making them valuable for early diagnosis and monitoring treatment responses. For instance, changes in specific miRNA levels within EVs could indicate tumor progression or response to therapy. Additionally, their non-invasive collection from blood or other body fluids enhances their utility in clinical settings, paving the way for personalized medicine approaches.

Related terms

Exosomes: Small extracellular vesicles formed by the inward budding of the plasma membrane, typically 30-150 nm in diameter, playing critical roles in cell communication and molecular transport.

Microvesicles: Larger extracellular vesicles ranging from 100 nm to 1 µm in size that bud directly from the plasma membrane, involved in various physiological and pathological processes.

Biomarkers: Biological molecules found in blood or other bodily fluids that indicate a normal or abnormal process, or a condition or disease; EVs can serve as potential biomarkers for various diseases.