mitochondrial dysfunction – Page 7 – American ME and CFS Society

Mitochondrial enzymes discriminate between mitochondrial disorders and chronic fatigue syndrome

Abstract:

We studied the extent of mitochondrial involvement in chronic fatigue syndrome (CFS) and investigated whether measurement of mitochondrial respiratory chain complex (RCC) activities discriminates between CFS and mitochondrial disorders.

Mitochondrial content was decreased in CFS compared to healthy controls, whereas RCC activities corrected for mitochondrial content were not. Conversely, mitochondrial content did not discriminate between CFS and two groups of mitochondrial disorders, whereas ATP production rate and complex I, III and IV activity did, all with higher activities in CFS. We conclude that the ATP production rate and RCC activities can reliably discriminate between mitochondrial disorders and CFS.

Source: Smits B, van den Heuvel L, Knoop H, Küsters B, Janssen A, Borm G, Bleijenberg G, Rodenburg R, van Engelen B. Mitochondrial enzymes discriminate between mitochondrial disorders and chronic fatigue syndrome. Mitochondrion. 2011 Sep;11(5):735-8. doi: 10.1016/j.mito.2011.05.005. Epub 2011 Jun 2. https://www.ncbi.nlm.nih.gov/pubmed/21664495

Assessment of Cellular Bioenergetics in Chronic Fatigue Syndrome

Introduction: Abnormalities in bioenergetic function have been cited as one possible cause for chronic fatigue syndrome (CFS). One hypothesis to explain this suggests that CFS may be caused, at least in part, by an acquired mitochondrial dysfunction.

Extracellular flux analysers make real-time, in vitro assessment of cellular energy pathways possible. Using this technology, mitochondrial function can be measured in a variety of cell types in real-time thus increasing our understanding of the role of metabolism in CFS.

Objectives: This project aims to utilise extracellular flux detection technology in order to investigate the cellular bioenergetics of different cell types obtained from CFS patients and healthy controls.

Methods: Mitochondrial stress tests were conducted using skeletal muscle cells and peripheral blood mononuclear cells (PBMCs) derived from CFS patients and controls. During this test mitochondrial complexes are inhibited in turn to modulate respiration so mitochondrial function can be evaluated. The oxygen consumption rate of cells is measured which allows keys parameters of mitochondrial function to be measured and calculated in a single experiment, providing an overall assessment of mitochondrial function. Parameters measured are: basal respiration, maximal respiration and non-mitochondrial respiration. Proton leak, ATP-production and spare respiratory capacity are subsequently able to be calculated using the three measured parameters. CFS patients whose samples were used in these studies were diagnosed using the Fukuda definition.

Results: Results using skeletal muscle cells obtained from CFS patients (n=3) and controls (n=5), indicate that there is no difference in the energy profiles of the skeletal muscle cells of CFS patients in any of the parameters investigated.

Mitochondrial stress test results using PBMCs show CFS PBMCs (n=7) to be significantly lower than control cells (n=10) in all parameters investigated (p≤0.016). Importantly, these results suggest that CFS PBMCs perform closer to their maximum under normal conditions. This means that when CFS PBMCs come under stress they are less able to increase their respiration rate to compensate for the increase in stress.

Conclusions: These findings provide an interesting starting point for investigations into cellular bioenergetics in CFS.

Cara Jasmine Tomas; First year medical science PhD student; Institute of Cellular Medicine, Level 1, William Leech Building, Medical School, Newcastle University, Newcastle Upon-Tyne, NE2 4HH, England; c.j.tomas@ncl.ac.uk
This work was funded by the Medical Research Council and Newcastle University.

Source: Cara Tomas, Julia Newton, Audrey Brown, Gina Rutherford, Philip Manning
Newcastle University, UK. Assessment of Cellular Bioenergetics in Chronic Fatigue Syndrome. Poster presentation, IACFS/ME 2016 conference.

Transcription profile analysis of vastus lateralis muscle from patients with chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS) is a disabling condition characterized by unexplained chronic fatigue that impairs normal activities. Many body systems are affected and etiology has not yet been identified. In addition to immunological and psychological aspects, skeletal muscle symptoms are prominent in CFS patients.

In an effort to establish which pathways might be involved in the onset and development of muscle symptoms, we used global transcriptome analysis to identify genes that were differentially expressed in the vastus lateralis muscle of female and male CFS patients.

We found that the expression of genes that play key roles in mitochondrial function and oxidative balance, including superoxide dismutase 2, were altered, as were genes involved in energy production, muscular trophism and fiber phenotype determination. Importantly, the expression of a gene encoding a component of the nicotinic cholinergic receptor binding site was reduced, suggesting impaired neuromuscular transmission. We argue that these major biological processes could be involved in and/or responsible for the muscle symptoms of CFS.

Source: Pietrangelo T, Mancinelli R, Toniolo L, Montanari G, Vecchiet J, Fanò G, Fulle S. Transcription profile analysis of vastus lateralis muscle from patients with chronic fatigue syndrome. Int J Immunopathol Pharmacol. 2009 Jul-Sep;22(3):795-807. https://www.ncbi.nlm.nih.gov/pubmed/19822097

Chronic fatigue syndrome and mitochondrial dysfunction

Abstract:

This study aims to improve the health of patients suffering from chronic fatigue syndrome (CFS) by interventions based on the biochemistry of the illness, specifically the function of mitochondria in producing ATP (adenosine triphosphate), the energy currency for all body functions, and recycling ADP (adenosine diphosphate) to replenish the ATP supply as needed.

Patients attending a private medical practice specializing in CFS were diagnosed using the Centers for Disease Control criteria. In consultation with each patient, an integer on the Bell Ability Scale was assigned, and a blood sample was taken for the “ATP profile” test, designed for CFS and other fatigue conditions. Each test produced 5 numerical factors which describe the availability of ATP in neutrophils, the fraction complexed with magnesium, the efficiency of oxidative phosphorylation, and the transfer efficiencies of ADP into the mitochondria and ATP into the cytosol where the energy is used. With the consent of each of 71 patients and 53 normal, healthy controls the 5 factors have been collated and compared with the Bell Ability Scale.

The individual numerical factors show that patients have different combinations of biochemical lesions. When the factors are combined, a remarkable correlation is observed between the degree of mitochondrial dysfunction and the severity of illness (P<0.001). Only 1 of the 71 patients overlaps the normal region.

The “ATP profile” test is a powerful diagnostic tool and can differentiate patients who have fatigue and other symptoms as a result of energy wastage by stress and psychological factors from those who have insufficient energy due to cellular respiration dysfunction. The individual factors indicate which remedial actions, in the form of dietary supplements, drugs and detoxification, are most likely to be of benefit, and what further tests should be carried out.

Source: Myhill S, Booth NE, McLaren-Howard J. Chronic fatigue syndrome and mitochondrial dysfunction. Int J Clin Exp Med. 2009;2(1):1-16. Epub 2009 Jan 15. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2680051/ (Full article)

Ventricular cerebrospinal fluid lactate is increased in chronic fatigue syndrome compared with generalized anxiety disorder: an in vivo 3.0 T (1)H MRS imaging study

Abstract:

Chronic fatigue syndrome (CFS) is a controversial diagnosis because of the lack of biomarkers for the illness and its symptom overlap with neuropsychiatric, infectious, and rheumatological disorders. We compared lateral ventricular volumes derived from tissue-segmented T(1)-weighted volumetric MRI data and cerebrospinal fluid (CSF) lactate concentrations measured by proton MRS imaging ((1)H MRSI) in 16 subjects with CFS (modified US Centers for Disease Control and Prevention criteria) with those in 14 patients with generalized anxiety disorder (GAD) and in 15 healthy volunteers, matched group-wise for age, sex, body mass index, handedness, and IQ.

Mean lateral ventricular lactate concentrations measured by (1)H MRSI in CFS were increased by 297% compared with those in GAD (P < 0.001) and by 348% compared with those in healthy volunteers (P < 0.001), even after controlling for ventricular volume, which did not differ significantly between the groups. Regression analysis revealed that diagnosis accounted for 43% of the variance in ventricular lactate.

CFS is associated with significantly raised concentrations of ventricular lactate, potentially consistent with recent evidence of decreased cortical blood flow, secondary mitochondrial dysfunction, and/or oxidative stress abnormalities in the disorder.

Source: Mathew SJ, Mao X, Keegan KA, Levine SM, Smith EL, Heier LA, Otcheretko V, Coplan JD, Shungu DC. Ventricular cerebrospinal fluid lactate is increased in chronic fatigue syndrome compared with generalized anxiety disorder: an in vivo 3.0 T (1)H MRS imaging study. NMR Biomed. 2009 Apr;22(3):251-8. doi: 10.1002/nbm.1315. https://www.ncbi.nlm.nih.gov/pubmed/18942064

Treating Chronic Fatigue states as a disease of the regulation of energy metabolism

Abstract:

Chronic Fatigue Syndrome is a physiological state in which the patient feels high levels of fatigue without an obvious organic cause, which affects around 1 in 400 people in the developed world. A wide range of causes have been suggested, including immune or hormonal dysfunction, viral or bacterial infection, and psychological somatization. It is likely that several causes are needed to trigger the disease, and that the triggers are different from the mechanisms that maintain fatigue over months or years. Many treatments have been tested for CFS, with very limited success – a programme of combined CBT and graded exercise shows the most effect.

I suggest that patients with CFS have a reduced ability to increase mitochondrial energy production when exertion requires it, with fewer mitochondria that are each more efficient, and hence nearer to their maximum energy output, than normal. A range of indirect evidence suggests that the renin-angiotensin system stimulates mitochondrial responsiveness and reduces mitochondrial efficiency: chronic under-stimulation of this system could contribute to CFS aetiology.

If correct, this means that CFS can be successfully treated with RAS agonists (eg angiotensin mimetics), or adrenergic agonists. It also suggests that there will be a positive link between the use of adrenergic- and RAS-blocking drugs and CFS incidence, and a negative link between adrenergic agonist use and CFS.

Source: Bains W. Treating Chronic Fatigue states as a disease of the regulation of energy metabolism. Med Hypotheses. 2008 Oct;71(4):481-8. doi: 10.1016/j.mehy.2008.02.022. Epub 2008 Aug 5. https://www.ncbi.nlm.nih.gov/pubmed/18684570

Heterogeneity in chronic fatigue syndrome: evidence from magnetic resonance spectroscopy of muscle

Abstract:

It has been shown previously that some patients with chronic fatigue syndrome show an abnormal increase in plasma lactate following a short period of moderate exercise, in the sub-anaerobic threshold exercise test (SATET).

This cannot be explained satisfactorily by the effects of ‘inactivity’ or ‘deconditioning’, and patients with abnormal lactate responses to exercise (SATET +ve) have been found to have significantly fewer Type 1 muscle fibres in quadriceps biopsies than SATET -ve patients. We performed phosphorus magnetic resonance spectroscopy on forearm muscles of 10 SATET +ve patients, 9 SATET -ve patients and 13 sedentary volunteers.

There were no differences in resting spectra between these groups but at the end of exercise, intracellular pH in the SATET +ve patients was significantly lower than in both the SATET -ve cases and controls (P < 0.03), and the SATET +ve patients also showed a significantly lower ATP synthesis rate during recovery (P < 0.01), indicating impaired mitochondrial oxidative phosphorylation.

These observations support other evidence which indicates that chronic fatigue syndrome is a heterogeneous disorder, and confirms the view that some chronic fatigue syndrome patients have a peripheral component to their fatigue.

Source: Lane RJ, Barrett MC, Taylor DJ, Kemp GJ, Lodi R. Heterogeneity in chronic fatigue syndrome: evidence from magnetic resonance spectroscopy of muscle. Neuromuscul Disord. 1998 May;8(3-4):204-9. http://www.ncbi.nlm.nih.gov/pubmed/9631403

Electron-microscopic investigation of muscle mitochondria in chronic fatigue syndrome

Abstract:

Patients with chronic fatigue syndrome (CFS) suffer from disabling physical and mental fatigue. Abnormalities in mitochondrial function can lead to fatigue and weakness. Ultrastructural mitochondrial abnormalities have been reported to be present in CFS patients.

We obtained percutaneous needle muscle biopsies from 15 CFS patients and 15 age- and sex-matched controls. We investigated previously reported ultrastructural abnormalites in CFS: subsarcolemmal mitochondrial aggregates, intermyofibrillar mitochondrial aggregates, mitochondrial circumference, area, pleomorphism and the presence of compartmentalization of the inner mitochondrial membrane. All of the steps of tissue processing, electron microscopy and data abstracting and analysis were performed in a totally blinded fashion. All of our data were rigorously quantified.

We found no difference in any of these studied parameters between CFS patients and controls. Although there is no ultrastructural mitochondrial abnormality in CFS patients, other lines of evidence suggest the presence of a possible functional mitochondrial abnormality.

Source: Plioplys AV, Plioplys S. Electron-microscopic investigation of muscle mitochondria in chronic fatigue syndrome. Neuropsychobiology. 1995;32(4):175-81. http://www.ncbi.nlm.nih.gov/pubmed/8587699