Tag: oxidative metabolism

Stress-inducible WASF3 regulates brain metabolism and cognitive function

Abstract:

Wiskott-Aldrich syndrome protein family member 3 (WASF3) disrupts mitochondrial respiration and is induced in association with endoplasmic reticulum stress in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Because cognitive impairment is a hallmark of ME/CFS, we investigated the role of WASF3 in brain metabolism and function using WASF3 transgenic and knockout mouse models.

WASF3 disrupted respiratory complex IV and localized to mitochondria-associated membranes, known to modulate cellular processes important for neuronal activity. Overexpression of WASF3 in the hippocampus, a critical region for memory formation, induced a metabolic shift toward glycolysis and promoted a “hypometabolic” state. Increased WASF3 also caused a reduction in ATPIF1, previously shown to facilitate cognitive function, and impaired learning. Conversely, WASF3 deficiency increased ATPIF1 level, enhanced oxidative metabolism, and preserved cognitive function under stress.

Together, these findings demonstrate that WASF3 suppresses oxidative metabolism in the brain and contributes to cognitive dysfunction, providing mechanistic insights into the “brain fog” reported in ME/CFS.

Source: Syed AM, Ma J, Wang PY, Son Y, Penjweini R, Mattu N, Knutson JR, Nakamori-Yamashita S, Springer DA, Ganguly A, Liu C, Hwang PM. Stress-inducible WASF3 regulates brain metabolism and cognitive function. Proc Natl Acad Sci U S A. 2026 Nov 3;123(44):e2617198123. doi: 10.1073/pnas.2617198123. Epub 2026 Oct 27. PMID: 42945241. https://www.pnas.org/doi/10.1073/pnas.2617198123 (Full text)

Phosphate diabetes in patients with chronic fatigue syndrome

Abstract:

Phosphate depletion is associated with neuromuscular dysfunction due to changes in mitochondrial respiration that result in a defect of intracellular oxidative metabolism. Phosphate diabetes causes phosphate depletion due to abnormal renal re-absorption of phosphate be the proximal renal tubule. Most of the symptoms presented by patients with phosphate diabetes such as myalgia, fatigue and mild depression, are also common in patients with chronic fatigue syndrome, but this differential diagnosis has not been considered.

We investigated the possible association between chronic fatigue syndrome and phosphate diabetes in 87 patients who fulfilled the criteria for chronic fatigue syndrome. Control subjects were 37 volunteers, who explicitly denied fatigue and chronic illness on a screening questionnaire.

Re-absorption of phosphate by the proximal renal tubule, phosphate clearance and renal threshold phosphate concentration were the main outcome measures in both groups. Of the 87 patients with chronic fatigue syndrome, nine also fulfilled the diagnostic criteria for phosphate diabetes.

In conclusion, we report a previously undefined relationship between chronic fatigue syndrome and phosphate diabetes. Phosphate diabetes should be considered in differential diagnosis with chronic fatigue syndrome; further studies are needed to investigate the incidence of phosphate diabetes in patients with chronic fatigue syndrome and the possible beneficial effect of vitamin D and oral phosphate supplements.

Comment in: Chronic fatigue syndrome. [Postgrad Med J. 1998]

 

Source: De Lorenzo F, Hargreaves J, Kakkar VV. Phosphate diabetes in patients with chronic fatigue syndrome. Postgrad Med J. 1998 Apr;74(870):229-32. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2360873/ (Full article)

 

Skeletal muscle metabolism in the chronic fatigue syndrome. In vivo assessment by 31P nuclear magnetic resonance spectroscopy

Abstract:

BACKGROUND: Previous study of patients with chronic fatigue syndrome (CFS) has demonstrated a markedly reduced dynamic exercise capacity, not limited by cardiac performance and in the absence of clinical neuromuscular dysfunction, suggesting the possibility of a subclinical defect of skeletal muscle.

METHODS: The in vivo metabolism of the gastrocnemius muscles of 22 CFS patients and 21 normal control subjects was compared during rest, graded dynamic exercise to exhaustion and recovery, using 31P nuclear magnetic resonance (NMR) spectroscopy to reflect minute-to-minute intracellular high-energy phosphate metabolism.

RESULTS: Duration of exercise was markedly shorter in the CFS patients (8.1 +/- 2.8 min) compared with the normal subjects (11.3 +/- 4.3 min) (p = 0.005). There were large changes in phosphocreatine (PCr), inorganic phosphate (Pi), and pH from rest to clinical fatigue in all subjects, reflecting the high intensity of the exercise. The temporal metabolic patterns were qualitatively similar in the CFS patients and normal subjects. There were early and continuous changes in PCr and Pi that peaked at the point of fatigue and rapidly reversed after exercise. In contrast, pH was relatively static in early exercise, not declining noticeably until 50 percent of total exercise duration was achieved, and reaching a nadir at 2 min postexercise, before rapidly reversing. There were no differences in pH at rest (7.08 +/- 0.04 vs 7.10 +/- 0.04), exhaustion (6.85 +/- 0.17 vs 6.76 +/- 0.17) or early (6.64 +/- 0.25 vs 6.56 +/- 0.24) or late recovery (7.09 +/- 0.04 vs 7.10 +/- 0.05), CFS patients vs normal subjects, respectively (NS). Neither were there intergroup differences (NS) in PCr or Pi. Although, quantitatively, the changes in PCr, Pi, and pH were marked and similar in both groups from rest to exhaustion, the changes all occurred much more rapidly in the CFS patients. Moreover, adenosine triphosphate (ATP) was significantly (p = 0.007) less at exhaustion in the CFS group.

CONCLUSIONS: Patients with CFS and normal control subjects have similar skeletal muscle metabolic patterns during dynamic exercise and reach similar clinical and metabolic end points. However, CFS patients reach exhaustion much more rapidly than normal subjects, at which point they also have relatively reduced intracellular concentrations of ATP. These data suggest a defect of oxidative metabolism with a resultant acceleration of glycolysis in the working skeletal muscles of CFS patients. This metabolic defect may contribute to the reduced physical endurance of CFS patients. Its etiology is unknown. Whether CFS patients’ overwhelming tiredness at rest has a similar metabolic pathophysiology or etiology also remains unknown.

 

Source: Wong R1, Lopaschuk G, Zhu G, Walker D, Catellier D, Burton D, Teo K, Collins-Nakai R, Montague T. Skeletal muscle metabolism in the chronic fatigue syndrome. In vivo assessment by 31P nuclear magnetic resonance spectroscopy. Chest. 1992 Dec;102(6):1716-22. http://www.ncbi.nlm.nih.gov/pubmed/1446478