E3 PreliminaryPreliminaryPEM requiredMechanisticPeer-reviewedReviewed
Genetic depletion of the early autophagy protein ATG13 impairs mitochondrial energy metabolism, augments oxidative stress, induces the polarization of macrophages to the M1 inflammatory mode, and compromises myelin integrity in skeletal muscle.
Toriola, Mubaraq A, Timlin, Emma, Bulbule, Sarojini et al. · Inflammation research : official journal of the European Histamine Research Society ... [et al.] · 2026 · DOI
Quick Summary
This study examined a protein called ATG13 that helps cells clean up damaged parts, particularly in immune cells called macrophages. When ATG13 was reduced, these immune cells couldn't work properly, their energy-producing structures (mitochondria) became dysfunctional, and they created too much harmful oxidative stress. This triggered the immune cells to switch into an inflammatory state and caused muscle weakness and nerve damage in a mouse model.
Why It Matters
This study identifies a potential molecular mechanism linking cellular autophagy dysfunction to excessive inflammation and post-exertional malaise—a hallmark symptom of ME/CFS where patients experience severe fatigue following minor exertion. Understanding how ATG13 deficiency leads to immune dysregulation and mitochondrial dysfunction could guide development of targeted therapies for ME/CFS patients who currently have no curative treatments.
Observed Findings
- ATG13 depletion reduced expression of autophagy markers (WDFY3, LC3) in macrophages.
- M1 macrophage markers (CD40, CD86) increased while M2 markers (CD163, CD206) decreased in ATG13-deficient mice.
- Mitochondrial oxygen consumption was impaired in ATG13-deficient macrophages as measured by Seahorse analysis.
- ROS levels increased in splenic macrophages lacking ATG13.
- Muscle strength declined following treadmill exercise, and myelin integrity deteriorated in nerve bundles of skeletal muscle.
Inferred Conclusions
- ATG13-driven autophagy is necessary for maintaining normal mitochondrial energy metabolism and preventing inflammatory macrophage activation.
- Impaired autophagy increases inflammation through a sirtuin-1/NF-κB signaling pathway, which may be relevant to post-exertional malaise pathogenesis.
- ATG13 deficiency causes both systemic immune dysregulation and local muscle pathology including myelin damage.
Remaining Questions
- Is ATG13 expression or function actually impaired in primary cells or tissues from ME/CFS patients, or is this mechanism specific to the knockout model?
- Does partial rather than complete ATG13 depletion produce similar effects, and are there dose-response relationships?
What This Study Does Not Prove
This study does not prove that ATG13 mutations or deficiency cause ME/CFS in humans, as it uses a genetically engineered mouse model with artificially depleted ATG13. The findings do not establish whether ATG13 dysfunction is a primary cause versus a consequence of ME/CFS pathology. It also does not demonstrate that correcting ATG13 expression would reverse symptoms in human patients.
Tags
Symptom:Post-Exertional MalaiseFatigue
Biomarker:CytokinesGene ExpressionBlood Biomarker
Method Flag:Exploratory OnlyPEM Not DefinedNo Controls
Metadata
- DOI
- 10.1007/s00011-025-02158-6
- PMID
- 41591477
- Review status
- Editor reviewed
- Evidence level
- Early hypothesis, preprint, editorial, or weak support
- Last updated
- 12 April 2026
About the PEM badge: “PEM required” means post-exertional malaise was an explicit required diagnostic criterion for participant inclusion in this study — not that PEM was studied, observed, or discussed. Studies using criteria that do not require PEM (e.g. Fukuda, Oxford) are tagged “PEM not required”. How the atlas works →
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