[EV] proteomics uncovers energy metabolism, complement system, and [ER] stress response dysregulation postexercise in males with [ME/CFS], 2025,Glass+

Extracellular vesicle proteomics uncovers energy metabolism, complement system, and endoplasmic reticulum stress response dysregulation postexercise in males with myalgic encephalomyelitis/chronic fatigue syndrome

Katherine A. Glass, Ludovic Giloteaux, Sheng Zhang, Maureen R. Hanson

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Background
Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating illness characterized by post-exertional malaise (PEM), a worsening of symptoms following exertion. The biological mechanisms underlying PEM remain unclear.

Extracellular vesicles (EVs) play a key role in cell–cell communication and may provide insight into ME/CFS pathophysiology post-exertion. Emerging evidence suggests similarities between ME/CFS and Long COVID, including PEM and overlapping immune and metabolic dysfunctions, highlighting the need for deeper mechanistic understanding.

Methods
This study explores the EV proteome response to exercise in 10 males with ME/CFS and 12 well-matched sedentary male controls. Participants underwent a maximal cardiopulmonary exercise test, and plasma samples were collected at baseline, 15 min, and 24 h postexercise.

EVs were isolated from plasma using size-exclusion chromatography and characterized with nanoparticle tracking analysis. EV protein abundance was quantified with untargeted proteomics (nanoLC-MS/MS). Comprehensive analyses included differential abundance, pathway enrichment, protein–protein interaction networks, and correlations between EV protein dynamics and clinical or exercise physiology data.

Results
ME/CFS patients exhibited many significantly altered EV proteomic responses compared with controls, including downregulation of TCA cycle-related proteins and upregulation of complement system proteins at 15 min postexercise.

Changes in proteins involved in protein folding and the endoplasmic reticulum (ER) stress response during recovery were highly correlated with PEM severity, highlighting their potential as therapeutic targets. EV protein changes postexercise were also associated with disease severity and unrefreshing sleep.

Correlations between EV protein levels and the exercise parameters VO₂ peak and ventilatory anaerobic threshold were observed in controls but were absent in ME/CFS patients, suggesting disrupted EV-mediated physiological processes.

Conclusions
ME/CFS patients exhibit a maladaptive EV proteomic response to exercise, characterized by metabolic impairments, immune overactivation, and ER stress response dysregulation. These findings provide insight into the molecular basis of PEM and suggest promising targets for improving recovery and energy metabolism in ME/CFS.

Key points

• EVs were isolated from plasma of ME/CFS patients and healthy controls at baseline, and 15 min and 24 h postexercise.
• Untargeted proteomics revealed dysregulation in energy metabolism, the complement system, and the endoplasmic reticulum stress response.
• Changes in EV protein levels postexercise are associated with post-exertional malaise.
• These findings suggest promising therapeutic targets for post-exertional malaise and ME/CFS pathophysiology.

Link | PDF (Clinical and Translational Medicine) [Open Access]

 

It’s a shame they didn’t get samples from 48 and 72 h as well.

 

Agreed, and small sample size is disappointing but the findings look interesting.

 

Probably budget limitations at the time of the testing, as usual.

 

BMI-matched sedentary male controls participated in this study

Good to see

 

Oh this is exactly the type of study I’ve been hoping for. I wish they’d had a 48 hour time point as well though. Quick skim through the methods doesn’t give me anything to complain about so far, everything lines up with the checks and balances I would expect from a robust analysis.

Only thing I’m always slightly concerned about is the amount of missingness and imputation. If they provide the data pre-imputation I’d like to manually check the how many of the top hits were from proteins with a lot of imputation.

Will probably come back to this after the initial excitement wears off and I have more time to dig into it.

 

Hopefully a bigger replication attempt is on the cards, especially if they think they've found therapeutic targets.

 

This publication is only on male ME/CFS patients. An earlier paper contained the data on female ME/CFS patients:

Giloteaux L, Glass KA, Germain A, Franconi CJ, Zhang S, Hanson MR. Dysregulation of extracellular vesicle protein cargo in female myalgic encephalomyelitis/chronic fatigue syndrome cases and sedentary controls in response to maximal exercise. J Extracell Vesicles. 2024;13(1):12403.

Thread:
Dysregulation of extracellular vesicle protein cargo in female ME/CFS cases & sedentary controls in response to maximal exercise, 2023 Giloteaux et al | Science for ME​

 

The differences between their male and female cohort are really quite striking. I would have expected at least a little more consistency between them.

Quick side note that their pathway analysis methodology differed between then two studies, though that probably wouldn’t drive the differences.

If the two year gap between this study and the last one was due to funding issues or time delay in cohort recruitment, then that would mean the samples weren’t all processed together. I think we ought to be mindful of likely batch effects confounding any sex effects.

 

There were analyzed separately—TMT is a method where you can multiplex (run multiple samples together to save resources and reduce batch effects) but all the analytes from each sample receive a unique “tag.” That allows you to demultiplex—i.e. retroactively assign readings to the samples they came from

 

Great, that the authors uploaded the data to mapmecfs.

Quite notable that study participation was concluded more than 5 years ago.

 

Aren’t those questionnaires affected by just being ill?