Tag: endoplasmic reticulum

Assessment of the therapeutic potential of salubrinal for ME/CFS and long-COVID

Highlights:

  • Long-COVID and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) are enigmatic diseases sharing many characteristics.
  • The most debilitating aspects of these diseases are cognitive dysfunction, ‘brain fog’, and exercise intolerance, ‘post-exertional malaise’.
  • There is no cure for these diseases; treatment is palliative only.
  • Mitochondrial dysfunction with endoplasmic reticulum (ER) stress occurs in both diseases.
  • Salubrinal inhibits the phosphatase that dephosphorylates phospho-eukaryotic initiation factor-2α (peIF2α), a protective protein for cells undergoing ER stress when phosphorylated.
  • Salubrinal reduces the formation of Wiskott–Aldrich syndrome protein family member 3 (WASF3), a protein that causes mitochondrial dysfunction that is overexpressed in a cohort of ME/CFS patients.
  • Salubrinal reduces WASF3 expression, restoring mitochondrial function in fibroblasts of a patient with ME/CFS.

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a chronic debilitating condition with no cure that shares commonality with long-COVID.

This review examines current understanding of long-COVID symptoms, characteristics of the affected population, the connection with ME/CFS, and the potential for salubrinal, an agent known for its influence on cellular stress pathways, to mitigate these disorders.

It also describes the historical development and mechanism of action of salubrinal, to mitigate endoplasmic reticulum (ER)/cellular stress responses, that could potentially contribute to symptom improvement in both ME/CFS and long-COVID patients.

Further research and clinical trials are warranted to advance our understanding of the potential role of salubrinal in improving the quality of life for individuals with long-COVID-related ME/CFS symptoms as well as ME/CFS patients.

Source: Aseel Warrayat, Ayah Ali, Joulin Waked, Darcy Tocci, Robert C. Speth. Assessment of the therapeutic potential of salubrinal for ME/CFS and long-COVID. Trends in Molecular Medicine, 2024. ISSN 1471-4914, https://doi.org/10.1016/j.molmed.2024.10.001. https://www.sciencedirect.com/science/article/abs/pii/S1471491424002685

WASF3 disrupts mitochondrial respiration and may mediate exercise intolerance in myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is characterized by various disabling symptoms including exercise intolerance and is diagnosed in the absence of a specific cause, making its clinical management challenging. A better understanding of the molecular mechanism underlying this apparent bioenergetic deficiency state may reveal insights for developing targeted treatment strategies.

We report that overexpression of Wiskott-Aldrich Syndrome Protein Family Member 3 (WASF3), here identified in a 38-y-old woman suffering from long-standing fatigue and exercise intolerance, can disrupt mitochondrial respiratory supercomplex formation and is associated with endoplasmic reticulum (ER) stress.

Increased expression of WASF3 in transgenic mice markedly decreased their treadmill running capacity with concomitantly impaired respiratory supercomplex assembly and reduced complex IV levels in skeletal muscle mitochondria. WASF3 induction by ER stress using endotoxin, well known to be associated with fatigue in humans, also decreased skeletal muscle complex IV levels in mice, while decreasing WASF3 levels by pharmacologic inhibition of ER stress improved mitochondrial function in the cells of the patient with chronic fatigue.

Expanding on our findings, skeletal muscle biopsy samples obtained from a cohort of patients with ME/CFS showed increased WASF3 protein levels and aberrant ER stress activation. In addition to revealing a potential mechanism for the bioenergetic deficiency in ME/CFS, our study may also provide insights into other disorders associated with fatigue such as rheumatic diseases and long COVID.

Source: Wang PY, Ma J, Kim YC, Son AY, Syed AM, Liu C, Mori MP, Huffstutler RD, Stolinski JL, Talagala SL, Kang JG, Walitt BT, Nath A, Hwang PM. WASF3 disrupts mitochondrial respiration and may mediate exercise intolerance in myalgic encephalomyelitis/chronic fatigue syndrome. Proc Natl Acad Sci U S A. 2023 Aug 22;120(34):e2302738120. doi: 10.1073/pnas.2302738120. Epub 2023 Aug 14. PMID: 37579159. https://pubmed.ncbi.nlm.nih.gov/37579159/