Understanding neuromuscular disorders in chronic fatigue syndrome

Abstract:

Muscle failure has been demonstrated in patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Neurophysiological tools demonstrate the existence of both central and peripheral fatigue in these patients. Central fatigue is deduced from the reduced amplitude of myopotentials evoked by transcranial magnetic stimulation of the motor cortex as well as by the muscle response to interpolated twitches during sustained fatiguing efforts. An impaired muscle membrane conduction velocity assessed by the reduced amplitude and lengthened duration of myopotentials evoked by direct muscle stimulation is the defining feature of peripheral fatigue.

Some patients with ME/CFS show an increased oxidative stress response to exercise. The formation of lipid hydroperoxides in the sarcolemma, which alters ionic fluxes, could explain the reduction of muscle membrane excitability and potassium outflow often measured in these patients. In patients with ME/CFS, the formation of heat shock proteins (HSPs) is also reduced. Because HSPs protect muscle cells against the deleterious effects of reactive oxygen species, the lack of their production could explain the augmented oxidative stress and the consecutive alterations of myopotentials which could open a way for future treatment of ME/CFS.

Copyright: © 2019 Jammes Y and Retornaz F.

Source: Jammes Y, Retornaz F. Understanding neuromuscular disorders in chronic fatigue syndrome.F1000Res. 2019 Nov 28;8. pii: F1000 Faculty Rev-2020. doi: 10.12688/f1000research.18660.1. eCollection 2019. https://www.ncbi.nlm.nih.gov/pubmed/31814961

Mechanisms Explaining Muscle Fatigue and Muscle Pain in Patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): a Review of Recent Findings

Abstract:

PURPOSE OF REVIEW: Here, we review potential causes of muscle dysfunction seen in many patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) such as the effects of oxidative and nitrosative stress (O&NS) and mitochondrial impairments together with reduced heat shock protein production and a range of metabolic abnormalities.

RECENT FINDINGS: Several studies published in the last few years have highlighted the existence of chronic O&NS, inflammation, impaired mitochondrial function and reduced heat shock protein production in many patients with ME/CFS. These studies have also highlighted the detrimental effects of chronically elevated O&NS on muscle functions such as reducing the time to muscle fatigue during exercise and impairing muscle contractility.

Mechanisms have also been revealed by which chronic O&NS and or impaired heat shock production may impair muscle repair following exercise and indeed the adaptive responses in the striated muscle to acute and chronic increases in physical activity. The presence of chronic O&NS, low-grade inflammation and impaired heat shock protein production may well explain the objective findings of increased muscle fatigue, impaired contractility and multiple dimensions of exercise intolerance in many patients with ME/CFS.

 

Source: Gerwyn M, Maes M. Mechanisms Explaining Muscle Fatigue and Muscle Pain in Patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): a Review of Recent Findings. Curr Rheumatol Rep. 2017 Jan;19(1):1. doi: 10.1007/s11926-017-0628-x. https://www.ncbi.nlm.nih.gov/pubmed/28116577

 

Epitopes of microbial and human heat shock protein 60 and their recognition in myalgic encephalomyelitis

Abstract:

Myalgic encephalomyelitis (ME, also called Chronic Fatigue Syndrome), a common disease with chronic fatigability, cognitive dysfunction and myalgia of unknown etiology, often starts with an infection. The chaperonin human heat shock protein 60 (HSP60) occurs in mitochondria and in bacteria, is highly conserved, antigenic and a major autoantigen.

The anti-HSP60 humoral (IgG and IgM) immune response was studied in 69 ME patients and 76 blood donors (BD) (the Training set) with recombinant human and E coli HSP60, and 136 30-mer overlapping and targeted peptides from HSP60 of humans, Chlamydia, Mycoplasma and 26 other species in a multiplex suspension array. Peptides from HSP60 helix I had a chaperonin-like activity, but these and other HSP60 peptides also bound IgG and IgM with an ME preference, theoretically indicating a competition between HSP60 function and antibody binding. A HSP60-based panel of 25 antigens was selected.

When evaluated with 61 other ME and 399 non-ME samples (331 BD, 20 Multiple Sclerosis and 48 Systemic Lupus Erythematosus patients), a peptide from Chlamydia pneumoniae HSP60 detected IgM in 15 of 61 (24%) of ME, and in 1 of 399 non-ME at a high cutoff (p<0.0001). IgM to specific cross-reactive epitopes of human and microbial HSP60 occurs in a subset of ME, compatible with infection-induced autoimmunity.

 

Source: Elfaitouri A, Herrmann B, Bölin-Wiener A, Wang Y, Gottfries CG, Zachrisson O, Pipkorn R, Rönnblom L, Blomberg J. Epitopes of microbial and human heat shock protein 60 and their recognition in myalgic encephalomyelitis. PLoS One. 2013 Nov 28;8(11):e81155. doi: 10.1371/journal.pone.0081155. ECollection 2013. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3842916/ (Full article)

 

Loss of stress response as a consequence of viral infection: implications for disease and therapy

Abstract:

Herein, we propose that viral infection can induce a deficient cell stress response and thereby impairs stress tolerance and makes tissues vulnerable to damage. Having a valid paradigm to address the pathological impacts of viral infections could lead to effective new therapies for diseases that have previously been unresponsive to intervention. Host response to viral infections can also lead to autoimmune diseases like type 1 diabetes. In the case of Newcastle disease virus, the effects of viral infection on heat shock proteins may be leveraged as a therapy for cancer. Finally, the search for a specific virus being responsible for a condition like chronic fatigue syndrome may not be worthwhile if the disease is simply a nonspecific response to viral infection.

 

Source: Hooper PL, Hightower LE, Hooper PL. Loss of stress response as a consequence of viral infection: implications for disease and therapy. Cell Stress Chaperones. 2012 Nov;17(6):647-55. doi: 10.1007/s12192-012-0352-4. Epub 2012 Jul 14. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3468676/ (Full article)

 

Chronic fatigue syndrome: acute infection and history of physical activity affect resting levels and response to exercise of plasma oxidant/antioxidant status and heat shock proteins

Abstract:

OBJECTIVES: A history of high-level physical activity and/or acute infection might constitute stress factors affecting the plasma oxidant-antioxidant status and levels of heat shock proteins (HSPs) in patients with chronic fatigue syndrome (CFS).

DESIGN: This case-control study compared data from 43 CFS patients to results from a matched control group of 23 healthy sedentary subjects.

SETTING AND SUBJECTS: Five patients had no relevant previous history (group I). Eighteen had practised high-level sport (group II), and severe acute infection had been diagnosed in nine patients (group III). A combination of sport practice and infection was noted in 11 patients (group IV).

INTERVENTIONS: After examination at rest, all subjects performed a maximal cycling exercise test. Plasma levels of two markers of oxidative stress [thiobarbituric acid reactive substances (TBARS) and reduced ascorbic acid (RAA)] and both HSP27 and HSP70 were measured.

RESULTS: At rest, compared with the control group, the TBARS level was higher in groups II, III and IV patients, and the RAA level was lower in groups III and IV. In addition, HSP70 levels were significantly lower in all CFS groups, compared with controls, but negative correlations were found between resting HSP27 and HSP70 levels and the history of physical activity. After exercise, the peak level of TBARS significantly increased in groups II, III and IV, and the variations in HSP27 and HSP70 were attenuated or suppressed, with the greatest effects in groups III and IV.

CONCLUSION: The presence of stress factors in the history of CFS patients is associated with severe oxidative stress and the suppression of protective HSP27 and HSP70 responses to exercise.

© 2011 The Association for the Publication of the Journal of Internal Medicine.

 

Source: Jammes Y, Steinberg JG, Delliaux S. Chronic fatigue syndrome: acute infection and history of physical activity affect resting levels and response to exercise of plasma oxidant/antioxidant status and heat shock proteins. J Intern Med. 2012 Jul;272(1):74-84. doi: 10.1111/j.1365-2796.2011.02488.x. Epub 2012 Jan 4. http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2796.2011.02488.x/full

 

Chronic fatigue syndrome combines increased exercise-induced oxidative stress and reduced cytokine and Hsp responses

Abstract:

OBJECTIVES: As heat shock proteins (Hsp) protect the cells against the deleterious effects of oxidative stress, we hypothesized that Hsp expression might be reduced in patients suffering from chronic fatigue syndrome (CFS) who present an accentuated exercise-induced oxidative stress.

DESIGN: This case-control study compared nine CFS patients to a gender-, age- and weight-matched control group of nine healthy sedentary subjects.

INTERVENTIONS: All subjects performed an incremental cycling exercise continued until exhaustion. We measured ventilation and respiratory gas exchange and evoked compound muscle potential (M-wave) recorded from vastus lateralis. Repetitive venous blood sampling allowed measurements of two markers of oxidative stress [thiobarbituric acid reactive substances (TBARS) and reduced ascorbic acid (RAA)], two cytokines (IL-6 and TNF-alpha) and two Hsp (Hsp27 and Hsp70) at rest, during maximal exercise and the 60-min recovery period.

RESULTS: Compared with controls, resting CFS patients had low baseline levels of RAA and Hsp70. Their response to maximal exercise associated (i) M-wave alterations indicating reduced muscle membrane excitability, (ii) early and accentuated TBARS increase accompanying reduced changes in RAA level, (iii) absence of significant increase in IL-6 and TNF-alpha, and (iv) delayed and marked reduction of Hsp27 and Hsp70 variations. The post-exercise increase in TBARS was accentuated in individuals having the lowest variations of Hsp27 and Hsp70.

CONCLUSIONS: The response of CFS patients to incremental exercise associates a lengthened and accentuated oxidative stress, which might result from delayed and insufficient Hsp production.

 

Source: Jammes Y, Steinberg JG, Delliaux S, Brégeon F.Chronic fatigue syndrome combines increased exercise-induced oxidative stress and reduced cytokine and Hsp responses. J Intern Med. 2009 Aug;266(2):196-206. doi: 10.1111/j.1365-2796.2009.02079.x. Epub 2009 May 19. https://www.ncbi.nlm.nih.gov/pubmed/19457057

 

Differential heat shock protein responses to strenuous standardized exercise in chronic fatigue syndrome patients and matched healthy controls

Abstract:

PURPOSE: Since physical exertion is known to exacerbate the symptoms of chronic fatigue syndrome (CFS) and metabolic changes and including oxidative stress can modulate heat shock protein (HSP) expression responses, we sought to determine whether HSP expression is altered in CFS patients before and after exercise. Heat shock proteins (HSPs) in peripheral blood mononuclear cells (PBMC) were examined from 6 chronic fatigue syndrome (CFS) patients and 7 controls before and after a standardized treadmill exercise. Basal hsp27 was significantly higher among CFS patients compared to controls, and decreased immediately post-exercise, remaining below basal levels even at 7 days. A similar pattern was observed for HSP60, which gradually decreased in CFS patients but increased in controls post-exercise. These findings suggest an abnormal adaptive response to oxidative stress in CFS, and raise the possibility that HSP profiling may provide a more objective biologic marker for this illness.

METHODS: HSP27, HSP60, HSP70 and HSP90 expression from 6 CFS patients and 7 age- and sex-matched controls were examined by western blot analysis of peripheral blood mononuclear cells immediately before, after, and at 1 day and 7 days following a standardized treadmill exercise.

RESULTS: Basal HSP27 was higher among CFS patients than in controls (0.54 +/- 0.13 vs. 0.19 +/- 0.06, mean +/- SEM; P < 0.01). In addition, these levels in CFS patients decreased immediately post-exercise (0.25 +/- 0.09; P < 0.05) and remained below basal levels at day 1 post-exercises (0.18 +/- 0.05; P < 0.05). P < 0.05). This declining expression of HSP27 during the post-exercise period among CFS patients was confirmed by one-way ANOVA analysis with repeated measures (P < 0.05). In contrast, HSP27 levels remained relatively constant following exercise among control subjects. Similar patterns of declining HSP levels in CFS patients were also observed for HSP60 (0.94 +/- 0.40 vs. 1.32 +/- 0.46; P < 0.05), and for HSP90 (0.34 +/- 0.09 vs. 0.49 +/- 0.10; P < 0.05) at day 7 post-exercise compared with basal levels, respectively. In contrast, HSP60 levels in control subjects increased at day 1 (1.09 +/- 0.27) and day 7 (1.24 +/- 0.50) post-exercise compared to corresponding levels immediately post-exercise (0.55 +/- 0.06) (P < 0.05, respectively).

CONCLUSION: These preliminary findings suggest an abnormal or defective adaptive response to oxidative stress in CFS, and raise the possibility that HSP profiling may provide a more objective biologic marker for this illness.

 

Source: Thambirajah AA, Sleigh K, Stiver HG, Chow AW. Differential heat shock protein responses to strenuous standardized exercise in chronic fatigue syndrome patients and matched healthy controls. Clin Invest Med. 2008 Dec 1;31(6):E319-27. https://www.ncbi.nlm.nih.gov/pubmed/19032901

 

Postulated vasoactive neuropeptide autoimmunity in fatigue-related conditions: a brief review and hypothesis

Abstract:

Disorders such as chronic fatigue syndrome (CFS) and gulf war syndrome (GWS) are characterised by prolonged fatigue and a range of debilitating symptoms of pain, intellectual and emotional impairment, chemical sensitivities and immunological dysfunction. Sudden infant death syndrome (SIDS) surprisingly may have certain features in common with these conditions. Post-infection sequelae may be possible contributing factors although ongoing infection is unproven. Immunological aberration may prove to be associated with certain vasoactive neuropeptides (VN) in the context of molecular mimicry, inappropriate immunological memory and autoimmunity.

Adenylate cyclase-activating VNs including pituitary adenylate cyclase-activating polypeptide (PACAP), vasoactive intestinal peptide (VIP) and calcitonin gene-related peptide (CGRP) act as hormones, neurotransmitters, neuroregulators, immune modulators and neurotrophic substances. They and their receptors are potentially immunogenic.

VNs are widely distributed in the body particularly in the central and peripheral nervous systems and have been identified in the gut, adrenal gland, blood cells, reproductive system, lung, heart and other tissues. They have a vital role in maintaining cardio-respiratory function, thermoregulation, memory, concentration and executive functions such as emotional responses including social cues and appropriate behaviour. They are co-transmitters for a number of neurotransmitters including acetylcholine and gaseous transmitters, are potent immune regulators with primarily anti-inflammatory activity, and have a significant role in protection of the nervous system against toxic assault as well as being important in the maintenance of homeostasis.

This paper describes a biologically plausible mechanism for the development of certain fatigue-related syndromes based on loss of immunological tolerance to these VNs or their receptors following infection, other events or de novo resulting in significant pathophysiology possibly mediated via CpG fragments and heat shock (stress) proteins. These conditions extend the public health context of autoimmunity and VN dysregulation and have implications for military medicine where radiological, biological and chemical agents may have a role in pathogenesis. Possible treatment and prevention options are considered.

 

Source: Staines DR. Postulated vasoactive neuropeptide autoimmunity in fatigue-related conditions: a brief review and hypothesis. Clin Dev Immunol. 2006 Mar;13(1):25-39. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2270748/ (Full article)

 

Do vasoactive neuropeptides and heat shock proteins mediate fatigue-related autoimmune disorders?

Abstract:

Autoimmune dysfunction of certain vasoactive neuropeptides may be implicated in a range of disorders associated with fatigue like states (chronic fatigue syndrome, Gulf War syndrome) and even sudden infant death syndrome. These substances have neurotrophic, neuroregulatory, and neurotransmission functions, as well as that of immune modulators and hormones. They exert significant control over carbohydrate and lipid metabolism.

The hypothesis is that because these substances have vital and indispensable roles in cellular processes, loss or compromise of these roles would lead to predictable and severe cellular and systemic effects. The important roles of certain VNs make them a vulnerable target for autoimmune dysfunction. They are known to be associated with heat shock proteins for intracellular functioning with which they may form immunostimulating complexes. While peptide-HSP complexes are a relatively new area for research, this paper asserts that attention could be focused on these substances and complexes in an effort to elucidate a number of perplexing fatigue-associated disorders.

 

Source: Staines DR. Do vasoactive neuropeptides and heat shock proteins mediate fatigue-related autoimmune disorders? Med Hypotheses. 2005;64(3):539-42. http://www.ncbi.nlm.nih.gov/pubmed/15617862