What are exosomes?
Cells constantly communicate with each other. They do this in many ways, including by releasing small membrane-bound particles called extracellular vesicles. Exosomes are one type of extracellular vesicle. They can carry a mixture of biological messages, including proteins, fats and genetic material, from one cell to another.
Because exosomes can influence how other cells behave, they are thought to play important roles in both health and disease. However, exosomes are highly diverse, and this variation has made it difficult for researchers to study them in detail or use them reliably in the clinic.
What the article explores
The Opinion article, co-authored by Professor Deborah Goberdhan and Oxford colleagues, Professor Adrian L Harris and Professor Clive Wilson considers how the origins of exosomes inside cells may shape their structure and function.
Exosomes form within internal cell compartments before being released outside the cell. Traditionally, researchers focused mainly on one type of compartment as the source of these vesicles. However, newer research suggests that several different internal membranes and cellular compartments can contribute to exosome formation.
This matters because exosomes are not all the same. Their internal origin may help determine what they carry, where they go, and how they affect recipient cells.
Figure 1: Different intracellular membranes contribute to exosome diversity.
Why this is important
Understanding how different types of exosomes are made could help researchers identify the specific exosome subtypes involved in particular diseases.
This could be important for conditions including cancer, neurodegenerative diseases, preeclampsia and endometriosis, where exosomes are thought to contribute to disease processes.
If researchers can distinguish between exosome subtypes more accurately, these vesicles could potentially be used as:
- Biomarkers to detect or monitor disease
- Therapeutic targets to block harmful cell communication
- Delivery tools to transport treatments to specific cells or tissues
Recent studies have overturned the dogma that exosomes are only made in late endosomes, highlighting contributions from recycling endosomal, autophagic and regulated secretory organelle membranes. These discoveries provide exciting new opportunities to facilitate the use of these complex messengers in diagnosing and treating disease.
- Professor Deborah Goberdhan, Associate Professor of Cell Signalling at the Nuffield Department of Women's & Reproductive Health
Building on previous research
Professor Goberdhan and colleagues have helped develop this area of research by identifying a subtype of exosome generated in a previously unsuspected cellular compartment associated with recycling within the cell.
Their work has shown that these exosomes are produced by many cell types and may have distinct roles in reproductive biology, cancer and neurodegeneration.
Looking ahead
The article highlights the need to better understand where exosomes come from inside cells and how this influences their behaviour.
By mapping these differences more precisely, researchers may be able to overcome some of the current challenges in detecting and targeting disease-relevant exosomes. This could support future work to develop more accurate diagnostic tools and new therapeutic strategies.
Publication
Read the full Opinion article in Trends in Cell Biology.