Major Conference Will Focus on Mitochondria - Defects Key to Understanding Chronic Fatigue Syndrome (CFS) (comments by Cheney included)
According to CFS expert doctor, Paul Cheney, "in CFS there is so much injury to the mitochondria that CFS could be called a mitochrondrial disease." It is good news for CFS research then, that a major conference is slated to look at mitochondria and diseases linked to mitochondrial defects. Although CFS is not specifically mentioned in the conference agenda, any developments in the field have great potential to assist CFS experts in their treatment efforts.
Electron-microscopic investigation of muscle mitochondria in chronic fatigue syndrome.
Plioplys AV, Plioplys S.Chronic Fatigue Syndrome Center, Mercy Hospital and Medical Center, Chicago, IL 60616, USA.
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.
Serum levels of carnitine in chronic fatigue syndrome: clinical correlates. Plioplys AV, Plioplys S. Neuropsychobiology. 1995;32(3):132-8. Chronic Fatigue Syndrome Center, Mercy Hospital and Medical Center, Chicago, Ill. 60616, USA.
Carnitine is essential for mitochondrial energy production. Disturbance in mitochondrial function may contribute to or cause the fatigue seen in chronic fatigue syndrome (CFS) patients. One previous investigation has reported decreased acylcarnitine levels in 38 CFS patients. We investigated 35 CFS patients (27 females and 8 males); our results indicate that CFS patients have statistically significantly lower serum total carnitine, free carnitine and acylcarnitine levels, not only lower acylcarnitine levels as previously reported. We also found a statistically significant correlation between serum levels of total and free carnitine and clinical symptomatology. Higher serum carnitine levels correlated with better functional capacity. These findings may be indicative of mitochondrial dysfunction, which may contribute to or cause symptoms of fatigue in CFS patients.
*O* Enteroviruses and postviral fatigue syndrome. Behan PO, Behan WM, Gow JW, Cavanagh H, Gillespie S.Department of Neurology, University of Glasgow, UK.
Postviral fatigue syndrome (PFS) occurs both in epidemics and sporadically. Many of the original epidemics were related to poliomyelitis outbreaks which either preceded or followed them. The core clinical symptoms are always the same: severe fatigue made worse by exercise, myalgia, night sweats, atypical depression and excessive sleep. The other common symptoms include dysequilibrium disorders and irritable bowel syndrome. We have detected enteroviral genome sequences in muscle biopsies from cases of PFS, using specific enteroviral oligonucleotide primers in the polymerase chain reaction (PCR). In addition, whole virus particles can be demonstrated in PCR-positive muscle, using solid-phase immuno-electron microscopy. An increase in the number and size of muscle mitochondria was found in 70% of PFS cases, suggesting an abnormality in metabolic function. Evidence of hypothalamic dysfunction was present, particularly involving 5-hydroxytryptamine metabolism. A putative model of PFS, based on persistent enteroviral infection in laboratory mice, revealed resolving inflammatory lesions in muscle with, however, a marked increase in the production of certain cytokines in the brain. This model may help to explain the pathogenesis of PFS.
Muscles, mitochondria and myalgia. Behan WM J Pathol. 1992 Mar;166(3):213-4.
*O* Mitochondrial abnormalities in the postviral fatigue syndrome. Behan WM, More IA, Behan PO. Acta Neuropathol (Berl). 1991;83(1):61-5. Department of Pathology, University of Glasgow, Scotland.
We have examined the muscle biopsies of 50 patients who had postviral fatigue syndrome (PFS) for from 1 to 17 years. We found mild to severe atrophy of type II fibres in 39 biopsies, with a mild to moderate excess of lipid. On ultrastructural examination, 35 of these specimens showed branching and fusion of mitochondrial cristae. Mitochondrial degeneration was obvious in 40 of the biopsies with swelling, vacuolation, myelin figures and secondary lysosomes. These abnormalities were in obvious contrast to control biopsies, where even mild changes were rarely detected. The findings described here provide the first evidence that PFS may be due to a mitochondrial disorder precipitated by a virus infection.
Acylcarnitine deficiency in chronic fatigue syndrome. Kuratsune H, Yamaguti K, Takahashi M, Misaki H, Tagawa S, Kitani T.Clin Infect Dis. 1994 Jan;18 Suppl 1:S62-7.Osaka University Medical School, Japan.
One of the characteristic complaints of patients with chronic fatigue syndrome (CFS) is the skeletal muscle-related symptom. However, the abnormalities in the skeletal muscle that explain the symptom are not clear. Herein, we show that our patients with CFS had a deficiency of serum acylcarnitine. As carnitine has an important role in energy production and modulation of the intramitochondrial coenzyme A (CoA)/acyl-CoA ratio in the skeletal muscle, this deficiency might induce an energy deficit and/or abnormality of the intramitochondrial condition in the skeletal muscle, thus resulting in general fatigue, myalgia, muscle weakness, and postexertional malaise in patients with CFS. Furthermore, the concentration of serum acylcarnitine in patients with CFS tended to increase to the normal level with the recovery of general fatigue. Therefore, the measurement of acylcarnitine would be a useful tool for the diagnosis and assessment of the degree of clinical manifestation in patients with CFS.
[Postviral fatigue syndrome] [Article in Norwegian] Haukenes G, Aarli JA.
Avdeling for mikrobiologi og immunologi Gades Institutt, Universitetet i Bergen, Armauer Hansens hus.
The post-viral fatigue syndrome occurs sporadically and in local outbreaks (Los Angeles, Akureyri, Royal Free Hospital). The clinical picture is marked by long-lasting muscular fatigue directly following an acute infection. Other conditions associated with pronounced fatigue must be excluded. The diagnostic criteria set up by Centers for Disease Control (CDC) are the ones most commonly used. Aetiology and pathogenesis are unknown. Coxsackie B-virus seems to be associated with some cases at least. Immunological and endocrinological aberration, morphological changes in mitochondria and reduced cerebral blood perfusion have been demonstrated in some patients. There is no specific therapy. It is important for the patient that the symptoms be accepted by the doctor and society in general.
Sensory characterization of somatic parietal tissues in humans with chronic fatigue syndrome. Vecchiet L, Montanari G, Pizzigallo E, Iezzi S, de Bigontina P, Dragani L, Vecchiet J, Giamberardino MA. Institute of Medical Pathophysiology, 'G. D'Annunzio' University of Chieti, Italy.
Patients with chronic fatigue syndrome (CFS) mainly complain of symptoms in the musculoskeletal domain (myalgias, fatigue). In 21 CFS patients the deep (muscle) versus superficial (skin, subcutis) sensitivity to pain was explored by measuring pain thresholds to electrical stimulation unilaterally in the deltoid, trapezius and quadriceps and overlying skin and subcutis in comparison with normal subjects. Thresholds in patients were normal in skin and subcutis but significantly lower than normal (hyperalgesia) in muscles (P < 0.001) in all sites. The selective muscle hypersensitivity corresponded also to fiber abnormalities at muscle biopsy (quadriceps) performed in nine patients which were absent in normal subjects (four cases): morphostructural alterations of the sarchomere, fatty degeneration and fibrous regeneration, inversion of the cytochrome oxidase/succinate dehydrogenase ratio, pleio/polymorphism and monstruosity of mitochondria, reduction of some mitochondrial enzymatic activities and increments of common deletion of 4977 bp of mitochondrial DNA 150-3000 times the normal values. By showing both sensory (diffuse hyperalgesia) and anatomical (degenerative picture) changes at muscle level, the results suggest a role played by peripberal mechanisms in the genesis of CFS symptoms. They would exclude the heightened perception of physiological signals from all districts hypothesized by some authors, especially as the hyperalgesia is absent in skin/subcutis.
*O* Role of mitochondria in neurodegenerative diseases Cassarino DS, Bennett JP Jr. University of Virginia Health Sciences Center, Charlottesville 22908, USA. Brain Research Reviews, 1999, Vol 29, Iss 1, pp 1-25
There is mounting evidence for mitochondrial involvement in neurodegenerative diseases including Alzheimer's, Parkinson's, and Lou Gehrig's Disease (ALS). Mitochondrial DNA mutations, whether inherited or acquired, lead to impaired electron transport chain (ETC) functioning. Impaired electron transport, in turn, leads to decreased ATP (energy) production, formation of damaging free-radicals, and altered calcium handling. These toxic consequences of ETC dysfunction lead to further mitochondrial damage including oxidation of mitochondrial DNA, proteins, and lipids, and opening of the mitochondrial permeability transition pore, an event linked to cell death. Although protective nuclear responses such as antioxidant enzymes may be induced to combat these pathological changes, such a vicious cycle of increasing oxidative damage may insidiously damage neurons over a period of years, eventually leading to neuronal cell death. This article's hypothesis, a synthesis of the mitochondrial mutations and oxidative stress hypotheses of neurodegeneration, is readily tested experimentally, and points out many potential therapeutic targets for preventing or ameliorating these diseases. PMID: 9974149
Muscle fibre characteristics and lactate responses to exercise in chronic fatigue syndrome Russell J M Lane,a Michael C Barrett,b David Woodrow,b Jill Moss,b Robert Fletcher,b Leonard C Archardc a Division of Neuroscience and Psychological Medicine, b Division of Diagnostic and Investigative Sciences, c Division of Biochemical Sciences, Imperial College School of Medicine, Charing Cross Hospital, London, UKJ Neurol Neurosurg Psychiatry 1998;64:362-367
OBJECTIVES To examine the proportions of type 1 and type 2 muscle fibres and the degree of muscle fibre atrophy and hypertrophy in patients with chronic fatigue syndrome in relation to lactate responses to exercise, and to determine to what extent any abnormalities found might be due to inactivity.
METHODS Quadriceps needle muscle biopsies were obtained from 105 patients with chronic fatigue syndrome and the proportions of type 1 and 2 fibres and fibre atrophy and hypertrophy factors were determined from histochemical preparations, using a semiautomated image analysis system. Forty one randomly selected biopsies were also examined by electron microscopy. Lactate responses to exercise were measured in the subanaerobic threshold exercise test (SATET).
RESULTS Inactivity would be expected to result in a shift to type 2 fibre predominance and fibre atrophy, but type 1 predominance (23%) was more common than type 2 predominance (3%), and fibre atrophy was found in only 10.4% of cases. Patients with increased lactate responses to exercise did have significantly fewer type 1 muscle fibres (p<0.043 males, p<0.0003 females), but there was no evidence that this group was less active than the patients with normal lactate responses. No significant ultrastructural abnormalities were found. CONCLUSION Muscle histometry in patients with chronic fatigue syndrome generally did not show the changes expected as a result of inactivity. However, patients with abnormal lactate responses to exercise had a significantly lower proportion of mitochondria rich type 1 muscle fibres.
The role of mitochondria in the pathogenesis of neurodegenerative diseases. Manfredi G, Beal MF Department of Neurology and Neuroscience, Weill Medical College of Cornell University and the New York Hospital, Cornell Medical Center, New York 10021, USA. gim2004@mail.med.cornell.edu Brain Pathol 2000 Jul;10(3):462-72
A growing body of evidence indicates that mitochondrial dysfunction may play an important role in the pathogenesis of many neurodegenerative disorders. Because mitochondrial metabolism is not only the principal source of high energy intermediates, but also of free radicals, it has been suggested that inherited or acquired mitochondrial defects could be the cause of neuronal degeneration as a consequence of energy defects and oxidative damage. Mitochondrial respiratory chain dysfunction has been reported in association with primary mitochondrial DNA abnormalities, and also as a consequence of mutations in nuclear genes directly involved in mitochondrial functions, such as SURF1, frataxin, and paraplegin. Defects of oxidative phosphorylation and increased free radical production have also been observed in diseases that are not due to primary mitochondrial abnormalities. In these cases, the mitochondrial dysfunction is likely to be an epiphenomenon, which, nevertheless, could be of importance in precipitating a cascade of events leading to cell death. In either case, understanding the role of mitochondria in the pathogenesis of neurodegenerative diseases could be important for the development of therapeutic strategies in these disorders.
United Mitochondrial Disease Foundation Mission:
To promote research and education for the diagnosis, treatment and cure of mitochondrial disorders and to provide support to affected individuals and families.
Some salient points arising from the AACFS 6th International Conference which the MRC Research Advisory Group on "CFS/ME" might wish to consider
Skeletal muscle function and mitochondrial function suggests a defect in oxidative metabolism with a residual acceleration of glycolysis in the working skeletal muscles in CFS. There is also reduced oxidative muscle metabolism (shown by MRI), and muscle recovery is delayed.
