1. Krämer-Albers EM, Werner HB (2023). Mechanisms of axonal support by oligodendrocyte-derived extracellular vesicles. Nat Rev Neurosci. Aug;24(8):474-486. doi: 10.1038/s41583-023-00711-y.
The transfer of extracellular vesicles (EVs) from myelinating oligodendrocytes to neurons is one of the best understood EV-dependent cell-cell communication pathways in the nervous system. This article discusses the role of exosomes in oligodendrocyte-neuron interaction and explains the molecular mechanisms of how these vesicles maintain axons and promote neuronal health. This could potentially translate into future therapeutic applications in neurodegenerative diseases.
2. Frühbeis C, Kuo-Elsner WP, Müller C, Barth K, Peris L, Tenzer S, Möbius W, Werner HB, Nave KA, Fröhlich D, and Krämer-Albers EM (2020). Oligodendrocytes support axonal transport and maintenance via exosome secretion. PLOS Biol. 18(12):e3000621. doi: 10.1371/journal.pbio.3000621.
This study explored the biological activity of oligodendrocyte-derived exosomes in neurons, demonstrating that neurons receiving these exosomes have a more robust energy metabolism and can maintain functions essential for their long-term survival. Consistently, mouse mutants that release a lower amount of oligodendroglial exosomes or exosomes of aberrant molecular composition develop a progressive axonopathy and have a reduced life-span.
3. Frühbeis C, Fröhlich D, Kuo WP, Amphornrat J, Thilemann S, Saab AS, Kirchhoff F, Möbius M, Goebbels S, Nave KA, Schneider A, Simons M, Klugmann M, Trotter J, and Krämer-Albers EM (2013) Neurotransmitter-triggered transfer of exosomes mediates oligodendrocyte-neuron communication, PLOS Biol 11(7):e1001604.
This article describes that extracellular vesicles (exosomes) are released by myelinating oligodendrocytes in response to neuronal electrical activity and then become internalized by neurons. After uptake into neurons, the molecular cargo becomes unpacked and is active in the neurons. The study showed that this also occurs in the brain (of mice) after injection of exosomes which carry a reporter enzyme.
4. Brahmer A, Neuberger E, Esch-Heisser L, Haller N, Jorgensen MM, Baek R, Möbius W, Simon P, Krämer-Albers EM. (2019) Platelets, endothelial cells and leukocytes contribute to the exercise-triggered release of extracellular vesicles into the circulation. J Extracell Vesicles. 8(1):1615820. doi: 10.1080/20013078.2019.1615820.
The group of Eva-Maria Krämer-Albers has discovered in 2015 that extracellular vesicles are actively released into the circulation of exercising humans (Frühbeis et al., JEV 2015). This follow-up study was very important to confirm and extend this initial finding using different EV isolation and characterization methodologies. The specific population of EVs released during exercise was termed “ExerVs”. The study shows that ExerVs are largely coming from cells associated with the circulation (white blood cells and endothelial cells). This basic information is relevant for further functional studies of these ExerVs.
5. Volz AK, Frei A, Kretschmer V, de Jesus Domingues AM, Ketting RF, Ueffing M, Boldt K, Krämer-Albers EM, May-Simera HL (2021) Bardet-Biedl syndrome proteins modulate the release of bioactive extracellular vesicles. Nat Commun. 12(1):5671. doi: 10.1038/s41467-021-25929-1.
All cells carry a primary cilium that is a sensing and signaling compartment. This study shows that ciliary signaling is linked to cell-cell communication via extracellular vesicles and this is relevant to ciliary diseases, which are multi-organ diseases. Intriguingly, Wnt signaling – a key pathway regulating developmental processes in different tissues - is modulated by EVs derived from cells with mutant ciliary proteins.