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Evaluation of the Storage Stability of Extracellular Vesicles
Published on: May 22, 2019
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Extracellular vesicles: another compartment for the second messenger, cyclic adenosine monophosphate
Sarah L Sayner1,2, Chung-Sik Choi1, Marcy E Maulucci1
1Department of Physiology Cell Biology, University of South Alabama , Mobile, Alabama.
American Journal of Physiology. Lung Cellular and Molecular Physiology
|February 14, 2019
Summary
Extracellular vesicles (EVs) from pulmonary microvascular endothelial cells carry cyclic AMP (cAMP), offering a new signaling compartment. These cAMP-laden EVs do not disrupt cell barriers, unlike free cAMP.
Area of Science:
- Cell Biology
- Molecular Signaling
- Biochemistry
Background:
- Cyclic AMP (cAMP) is a crucial second messenger for cellular signaling specificity.
- Extracellular vesicles (EVs) are involved in intercellular communication and can serve as biomarkers.
- The presence of cyclic nucleotides within EVs remains largely unexplored.
Purpose of the Study:
- To investigate whether cyclic AMP (cAMP) is encapsulated within extracellular vesicles (EVs).
- To determine if EVs provide an additional compartment for cAMP signaling.
- To assess the functional impact of cAMP-containing EVs on endothelial cell barrier integrity.
Main Methods:
- Isolation of EVs from endothelial cells using ultracentrifugation.
- Stimulation of pulmonary microvascular endothelial cells (PMVECs) with agents affecting adenylyl cyclase and phosphodiesterase 4.
- Measurement of intracellular and intra-EV cAMP levels over time.
- Assessment of endothelial monolayer resistance upon addition of cAMP-containing EVs.
Main Results:
- Cyclic AMP (cAMP) was detected in EVs from various endothelial cells, with highest levels in those from PMVECs.
- Stimulating PMVECs increased intra-EV cAMP, with a delayed peak compared to intracellular cAMP.
- EVs containing elevated cAMP did not disrupt endothelial monolayer resistance.
- EVs from stimulated rat lungs also showed increased cAMP, confirming cell culture findings.
Conclusions:
- Pulmonary microvascular endothelial cells release EVs that encapsulate cyclic AMP (cAMP).
- EVs represent a novel compartment for cAMP signaling, distinct from cytosolic pools.
- cAMP-loaded EVs maintain endothelial barrier function, suggesting a regulatory role in vascular physiology.
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