Summary: Physical exercise triggers tiny particles in the blood known as extracellular vesicles (EVs) to act as temporary transport shuttles for important hormone precursors. During vigorous exercise, the amount of the hormone precursor proopiomelanocortin (POMC) associated with EVs increases about fourfold, revealing a potential mechanism by which movement can rapidly alter stress responses, energy balance, and mood.
EV-associated POMC also crosses blood vessel barriers, including the blood–brain barrier, more effectively than free POMC. These results provide new insight into how exercise might influence brain function and open possibilities for better understanding metabolism, pain relief, mental health, immune responses, and targeted drug delivery.
Key Facts:
- Exercise Increases POMC Transport: Vigorous physical activity produces roughly a fourfold rise in the amount of POMC carried by extracellular vesicles in the bloodstream.
- Improved Barrier Crossing: POMC bound to EVs crosses biological barriers, including the blood–brain barrier, more efficiently than unbound POMC.
- Broad Health Relevance: This EV-based transport mechanism may influence pain modulation, stress responses, metabolism, inflammation, and future strategies for delivering therapies to the brain.
Source: Touro University
Overview
Researchers at Touro University Nevada report that extracellular vesicles (EVs)—minute, membrane-enclosed particles present in blood and other body fluids—play a major role in shuttling a hormone precursor called proopiomelanocortin (POMC) through the body. The study, published in the journal Proceedings of the National Academy of Sciences (PNAS), examined how exercise influences the relationship between EVs and hormone precursors and explored how EVs affect access to tissues that are normally difficult to reach, such as the brain.
EVs are produced by cells throughout the body and carry biological cargo including proteins, lipids, and nucleic acids. They mediate cell-to-cell communication both locally and across organs, and they help remove cellular waste. Scientists have already linked EVs to immune signaling and cancer biology, but their interactions with endocrine molecules have been less well understood until now.
The research team targeted POMC because this precursor is processed into several biologically active hormones, including endorphins—often associated with the “runner’s high”—and adrenocorticotropic hormone (ACTH), which helps regulate the stress response. Because physical exercise is known to affect these hormone systems, the investigators used vigorous exercise as a physiological trigger to reveal how POMC and EVs interact.
In laboratory studies, the scientists found that vigorous exercise markedly increases the proportion of POMC that attaches to EVs. They demonstrated roughly a fourfold increase in EV-bound POMC following intense physical activity. In cell-based models of human blood vessel barriers, EV-associated POMC moved across endothelial layers, including models of the blood–brain barrier, more efficiently than POMC by itself.
Lead author Mark Santos, Ph.D., assistant professor at Touro University Nevada, said the work “doesn’t just show an ‘exercise effect’ but reveals a new biological mechanism where stress from exercise makes EVs temporarily act as hormone transport shuttles in the bloodstream.” The research suggests that EVs can rapidly redistribute hormone precursors in response to physiological stressors like exercise.
Although POMC must be processed into mature peptide hormones to elicit specific actions in target tissues, including the brain, the finding that EVs improve the delivery of POMC across vascular barriers raises testable questions about how exercise-induced changes in circulating EVs might influence central nervous system function. Further studies will be needed to determine whether EV-bound POMC is processed into active hormones after crossing barriers and how this process affects behavior, mood, and metabolic regulation.
Co-senior author Aurelio Lorico, MD, PhD, professor of pathology at Touro, emphasized the wide-ranging implications: “The observation that EVs can carry POMC points to many potential directions. It may have implications for pain management, obesity and metabolic disease, inflammation, and the body’s stress response.” The research team includes collaborators who are exploring these possible links while carefully testing the molecular and physiological steps involved.
Key Questions Answered:
A: They found that vigorous exercise causes extracellular vesicles to carry substantially more POMC through the bloodstream, suggesting EVs act as transient hormone transport shuttles during physiological stress.
A: EV-bound POMC crosses biological barriers more effectively than free POMC, indicating a potential pathway by which peripheral stress signals and hormone precursors can influence the brain and other protected tissues.
A: Understanding EV-based hormone transport could guide new strategies for treating pain, metabolic disorders, stress-related conditions, and for improving the delivery of therapeutics to the brain.
Editorial Notes:
- This article was edited by a Neuroscience News editor.
- The original journal paper was reviewed in full by the editorial team.
- Additional context was added by staff to clarify implications and experimental scope.
About this exercise and neuroscience research news
Author: Ellie Schlam ([email protected])
Source: Touro University
Contact: Ellie Schlam – Touro University
Image: The image is credited to Neuroscience News
Original Research: The findings are reported in Proceedings of the National Academy of Sciences (PNAS).