WASF3 disrupts mitochondrial respiration and may mediate exercise intolerance in myalgic encephalomyelitis/chronic fatigue syndrome.
Level 4 - case-series / case-control
Case-control skeletal muscle biopsy evaluation and single-patient cellular study combined with animal/in vitro models
PubMed 37579159 · doi:10.1073/pnas.2302738120
What was done
Researchers investigated bioenergetic deficiency mechanisms in ME/CFS starting from an index case of a 38-year-old woman with chronic fatigue and exercise intolerance. They generated transgenic mice overexpressing WASF3, tested endotoxin-induced endoplasmic reticulum (ER) stress in mice, evaluated pharmacological ER stress inhibition in patient-derived cells, and analyzed skeletal muscle biopsy samples from a cohort of patients with ME/CFS compared to controls.
What was found
The abstract reports no exact numerical values, effect sizes, or p-values. Qualitatively, WASF3 overexpression disrupted mitochondrial respiratory supercomplex assembly and was associated with ER stress. Transgenic mice overexpressing WASF3 showed markedly decreased treadmill running capacity, impaired supercomplex assembly, and decreased complex IV levels in skeletal muscle mitochondria. Inducing ER stress via endotoxin in mice raised WASF3 and lowered complex IV levels. Pharmacological inhibition of ER stress reduced WASF3 and improved mitochondrial function in patient cells. Finally, skeletal muscle biopsies from the ME/CFS patient cohort demonstrated increased WASF3 protein levels and aberrant ER stress activation.
Why it matters
This study links ER stress and WASF3 upregulation to mitochondrial supercomplex disruption and reduced exercise capacity. It identifies a candidate molecular pathway and therapeutic target for post-exertional fatigue in ME/CFS and potentially related conditions like post-acute sequelae of COVID-19.
Limits
The abstract reports no quantitative measurements, confidence intervals, or sample sizes for the ME/CFS cohort or animal groups. Findings rely substantially on animal models and a single-patient cellular system; clinical generalizability to broader, heterogeneous ME/CFS populations remains to be established in prospective human trials.
Cited by
- supports A recent study analyzing muscle biopsies from the quadriceps of chronic fatigue syndrome patients found a significantly lower mitochondrial energy transformation capacity.