The Role of Cytokines in Muscle Fatigue in Patients with Chronic Fatigue Syndrome

[msf]

I would agree that this work is necessary, in that it confirms things that most people on this forum already suspected, but it is also not really telling us anything new. Why are there increased oxidative species or increased levels of lactic acid? It seems a pity that these groups have to (or feel they have to) replicate findings that were published many years ago, but I guess that is a result of the funding problem/lack of interest in ME research.

 

[charles shepherd]

There has definitely been further work that supports this.

Skeletal muscle metabolism in the chronic fatigue syndrome. In vivo assessment by 31P nuclear magnetic resonance spectroscopy. Chest. 1992 Dec;102(6):1716-22.

"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."


Muscle fibre characteristics and lactate responses to exercise in chronic fatigue syndrome. J Neurol Neurosurg Psychiatry. 1998 Mar;64(3):362-7.

"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."


Heterogeneity in chronic fatigue syndrome: evidence from magnetic resonance spectroscopy of muscle. Neuromuscul Disord. 1998 May;8(3-4):204-9.

"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."


Enterovirus related metabolic myopathy: a postviral fatigue syndrome J Neurol Neurosurg Psychiatry. 2003 Oct; 74(10): 1382–1386.

"There is an association between abnormal lactate response to exercise, reflecting impaired muscle energy metabolism, and the presence of enterovirus sequences in muscle in a proportion of CFS patients."

Yes, there were these small studies looking at mitochondrial structure and function following The Lancet paper, and I have a few more small studies in my library

But the sad fact is that the momentum for carrying out significant research into mitochondrial dysfunction and challenging the widespread medical view that muscle fatigue and weakness is due to decondition didn't take place at the time this model was rapidly gaining approval in the 1980s - certainly here in the UK

 

[charles shepherd]

I would agree that this work is necessary, in that it confirms things that most people on this forum already suspected, but it is also not really telling us anything new. Why are there increased oxidative species or increased levels of lactic acid? It seems a pity that these groups have to (or feel they have to) replicate findings that were published many years ago, but I guess that is a result of the funding problem/lack of interest in ME research.

As I've already indicated, these are some very preliminary results on ONE COMPONENT of this research (which has not yet been completed) into mitochondrial function in ME/CFS, along with examination of possible therapeutic interventions (which is not covered in this abstract).

If you feel that there is already sound information on the type of cytokine mediated inflammation in skeletal muscle that McArdle et al are looking at out there in the scientific literature could you let me know where this is?

C

 

[Gijs]

To my mind it is news because it is much more specific than that. It is specifically after exercise, as I understand it. And it is a mediator specifically chosen to test a hypothesis, measured in blinded samples by a laboratory that takes care to make sure their data are solid. It may be nothing more than a formal validation of what is known anecdotally but that is a huge step forward in ME research. All we really need in ME research is for all these things that 'everybody knows' to be demonstrated with a level of quality control that allows us to build on them as established biomarkers. To be honest I read dozens of ME research papers each month and for most of them by the end of the abstract I know that I am not going to have confidence in the findings. This looks plausible.

Thank you for your reply. I know that professsor Julia Newton from the Newcastle university is also looking into the mucle. In her study, she took muscle biopsies from ten patients and ten healthy but sedentary volunteers.
The muscle cells were grown into small pieces of muscle and then subjected to “exercise” in the form of electrical impulses in the lab. The cells from ME patients produced on average 20 times as much acid when exercised.
These cells also reproducing more slowly in ME-patiënts. This has nothing to do with deconditioning because her results came from new grown cells in the lab.

 

[msf]

No, that wasn't my point, I don't think they are needlessly replicating prior studies, I was bemoaning the fact that this kind of study wasn't done a long time ago, as you were. Perhaps I was overlooking the fact that this research may tie together several different suggested aspects of ME (cytokines, reactive oxygen species, lactic acid (hopefully) and muscle fatigue.

This would help our understanding of the physiopathology of the disease, but unless I am wrong it wouldn't bring us any closer to the cause (whatever is causing the increased levels of cytokines).

 

[msf]

Or what is causing the increased levels of lactic acid.

 

[charles shepherd]

Thank you for your reply. I know that professsor Julia Newton from the Newcastle university is also looking into the mucle. In her study, she took muscle biopsies from ten patients and ten healthy but sedentary volunteers.
The muscle cells were grown into small pieces of muscle and then subjected to “exercise” in the form of electrical impulses in the lab. The cells from ME patients produced on average 20 times as much acid when exercised.
These cells also reproducing more slowly in ME-patiënts. This has nothing to do with deconditioning because her results came from new grown cells in the lab.

Yes, Julia released some preliminary results from this research to coincide with the launch of the UK Research Collaborative and they were reported in The Times:

http://www.meassociation.org.uk/201...ope-for-me-sufferers-the-times-23-april-2013/

 

[msf]

Oops, I meant pathophysiology, not physiopathology (although it seems to be a variant of the former).

 

[charles shepherd]

No, that wasn't my point, I don't think they are needlessly replicating prior studies, I was bemoaning the fact that this kind of study wasn't done a long time ago, as you were. Perhaps I was overlooking the fact that this research may tie together several different suggested aspects of ME (cytokines, reactive oxygen species, lactic acid (hopefully) and muscle fatigue.

This would help our understanding of the physiopathology of the disease, but unless I am wrong it wouldn't bring us any closer to the cause (whatever is causing the increased levels of cytokines).

This is the (very plausible) hypothesis behind part of this research:

Chronic ROS generation by muscle mitochondria is proposed to result in chronic activation of NFkB and subsequent lowgrade inflammation. We further hypothesise that activation of NFkB results in muscle becoming a major source of systemic pro-inflammatory cytokines, resulting in further mitochondrial abnormalities and the establishment of a vicious circle of events.

ROS = reactive oxygen species

 

[Sidereal]

Sadly, despite these findings being published in The Lancet, this was then followed by a prolonged absence of any significant muscle research taking place.

Well, in fairness, some people did try to replicate those initial positive findings and, as so often happens in science, were unable to do so in the majority of patients diagnosed with the construct of chronic fatigue syndrome. It would appear that your case is atypical.

Quoting from the introduction of the paper @halcyon cited:

Heterogeneity in chronic fatigue syndrome: evidence from magnetic resonance spectroscopy of muscle. Neuromuscul Disord. 1998 May;8(3-4):204-9.

In 1984, Arnold et al. [18] reported abnormal phosphorus magnetic resonance spectroscopy (MRS) findings in forearm muscles in a 30-year-old doctor who developed postviral fatigue syndrome following varicella-zoster infection. Muscle metabolism was normal at rest but aerobic exercise induced an excessive intracellular acidosis, markedly disproportionate to phosphocreatine (PCr) depletion, and the rate of phosphocreatine regeneration post-exercise was also slowed while free [ADP], the main stimulus to mitochondrial ATP synthesis, was not increased.

These authors subsequently reported MRS findings in five further patients with similar clinical features [19]. While early excessive intracellular acidification was common, this was disproportionate to PCr depletion in only one other case. In addition, they found that such changes could be seen in a variety of other conditions, while many cases of ‘postviral fatigue syndrome’ had normal MRS findings.

Subsequent larger studies have confirmed that there are no specific or consistent MRS changes in the majority of CFS patients [20,21], although a significant minority of cases do show abnormalities, including more rapid exhaustion with lower end-exercise intracellular ATP concentrations than normal subjects [22], and reduced maximal rates of mitochondrial ATP synthesis [23,24].

[20] Barnes PRJ, Taylor DJ, Kemp GJ, Radda GK. Skeletal muscle bioenergetics in the chronic fatigue syndrome. J Neurol Neurosurg Psychiatry 1993;56:679–683.

[21] Kent-Braun J, Sharma KR, Weiner MW, Massie B, Miller RG. Central basis of muscle fatigue in chronic fatigue syndrome. Neurology 1993;43:125–131.

[22] Wong R, Lopachuk G, Zhu G. et al. Skeletal muscle metabolism in the chronic fatigue syndrome: in vivo assessment by 31P nuclear magnetic resonance spectroscopy. Chest 1992;102:1716–1722.

Now, of course, we can critique those studies and say that they used inappropriate design (single exercise challenge) when we know now, in hindsight, from the 2-day CPET work that milder cases may not show metabolic abnormalities unless you induce PEM in them first and then retest them while they are PEMmed. Pummelled by PEM.

 

[charles shepherd]

Well, in fairness, some people did try to replicate those initial positive findings and, as so often happens in science, were unable to do so in the majority of patients diagnosed with the construct of chronic fatigue syndrome. It would appear that your case is atypical.

Reply:


Yes, the numbers are small in all these muscle studies - so it's difficult to know what percentage of the ME/CFS population have this abnormality

My gut feeling remains that there is a sub-group with significant muscle abnormalities relating to acid handling - and in this respect we may be dealing with a type of post infectious mitochondrial myopathy

Did you see this more recent research from Julia Newton et al, which was funded by the MEA:

http://www.ncbi.nlm.nih.gov/pubmed/21749371

Eur J Clin Invest. 2012 Feb;42(2):186-94. doi: 10.1111/j.1365-2362.2011.02567.x. Epub 2011 Jul 12.
Loss of capacity to recover from acidosis on repeat exercise in chronic fatigue syndrome: a case-control study.
Jones DE1, Hollingsworth KG, Jakovljevic DG, Fattakhova G, Pairman J, Blamire AM, Trenell MI, Newton JL.
Author information

Abstract
BACKGROUND:
Chronic fatigue syndrome (CFS) patients frequently describe difficulties with repeat exercise. Here, we explore muscle bioenergetic function in response to three bouts of exercise.
METHODS:
A total of 18 CFS (CDC 1994) patients and 12 sedentary controls underwent assessment of maximal voluntary contraction (MVC), repeat exercise with magnetic resonance spectroscopy and cardio-respiratory fitness test to determine anaerobic threshold.
RESULT:
Chronic fatigue syndrome patients undertaking MVC fell into two distinct groups: 8 (45%) showed normal PCr depletion in response to exercise at 35% of MVC (PCr depletion >33%; lower 95% CI for controls); 10 CFS patients had low PCr depletion (generating abnormally low MVC values). The CFS whole group exhibited significantly reduced anaerobic threshold, heart rate, VO(2) , VO(2) peak and peak work compared to controls. Resting muscle pH was similar in controls and both CFS patient groups. However, the CFS group achieving normal PCr depletion values showed increased intramuscular acidosis compared to controls after similar work after each of the three exercise periods with no apparent reduction in acidosis with repeat exercise of the type reported in normal subjects. This CFS group also exhibited significant prolongation (almost 4-fold) of the time taken for pH to recover to baseline.
CONCLUSION:
When exercising to comparable levels to normal controls, CFS patients exhibit profound abnormality in bioenergetic function and response to it. Although exercise intervention is the logical treatment for patients showing acidosis, any trial must exclude subjects who do not initiate exercise as they will not benefit. This potentially explains previous mixed results in CFS exercise trials.

 

[Sidereal]

My gut feeling remains that there is a sub-group with significant muscle abnormalities relating to acid handling - and in this respect we may be dealing with a type of post infectious mitochondrial myopathy

Yes, only a small number of cases have been studied so far, but the fact that this problem with acid handling could only be demonstrated in a minority of studied cases still leaves the elephant in the room of unexplained muscle fatigue and pain in everyone else with this diagnosis.

Did you see this more recent research from Julia Newton et al, which was funded by the MEA:

Thanks. I'm aware of Dr Newton's study but don't agree with its conclusions. The discussion in that paper borders on bizarre, to be honest.

 

[Gijs]

I think a sort of autoimmunity (or infection) against Lipid raft could explain everything especially caveolins they are widely expressed in the brain, micro-vessels of the nervous system, endothelial cells, astrocytes, oligodendrocytes, Schwann cells, dorsal root ganglia and hippocampal neurons.

 

[Dr Speedy]

Worth noting that skeletal muscle produces significant amounts of the cytokine interleukin 6 during exercise:

http://www.ncbi.nlm.nih.gov/pubmed/23663276

"Skeletalmuscle produces and releases significant levels of IL-6 after prolonged exercise"

Please note that's after prolonged exercise

 

[Dr Speedy]

Anybody know which criteria were used in the study ?

"Subjective fatigue was higher in patients with CFS compared with HCs."

Because many patients with severe ME suffer from severe muscle fatigue but not from fatigue. Tired all the time we are not.

 

[bertiedog]

Anybody know which criteria were used in the study ?

"Subjective fatigue was higher in patients with CFS compared with HCs."

Because many patients with severe ME suffer from severe muscle fatigue but not from fatigue. Tired all the time we are not.

Yes I can have really good energy after resting, the problem is that it runs out so quickly when I do anything physical and I end up with lots of pain in my muscles and if I continue on too long then I will get severe dizziness (and of course my cognitive function which is generally good, goes to pot. This has happened every day since 2000 when I finally crashed completely. Treating the thyroid and adrenals gave me back the energy plus supplements like co-q 10, magnesium etc but it certainly didn't solve the inability to exercise that I have. I also benefit hugely from using an oxygen concentrator daily which seems to put back what my body has lost from the activities I am able to do.

Personally I feel I would hugely benefit if there was something I could take to stop this muscle problem from kicking in every day when doing normal activities like walking my dog. Surely its not too much to hope for so I for one am very grateful that this sort of research is taking place in the UK. I actually feel quite proud that the charities are getting stuff done at last here in the UK. My thanks go to Charles and of course to Professor Edwards for all their work on our behalf. I do try and regularly give a donation to Invest in ME just to help things along a bit.

Pam

 

[charles shepherd]

Abnormalities of AMPK Activation and Glucose Uptake in Cultured Skeletal Muscle Cells from Individuals with Chronic Fatigue Syndrome


Julia Newton research involving muscle cell culture now published:
Abstract

Background

Post exertional muscle fatigue is a key feature in Chronic Fatigue Syndrome (CFS).
Abnormalities of skeletal muscle function have been identified in some but not all patients with CFS.
To try to limit potential confounders that might contribute to this clinical heterogeneity, we developed a novel in vitro system that allows comparison of AMP kinase (AMPK) activation and metabolic responses to exercise in cultured skeletal muscle cells from CFS patients and control subjects.
Methods

Skeletal muscle cell cultures were established from 10 subjects with CFS and 7 age-matched controls, subjected to electrical pulse stimulation (EPS) for up to 24h and examined for changes associated with exercise.
Results

In the basal state, CFS cultures showed increased myogenin expression but decreased IL6 secretion during differentiation compared with control cultures.
Control cultures subjected to 16h EPS showed a significant increase in both AMPK phosphorylation and glucose uptake compared with unstimulated cells.
In contrast, CFS cultures showed no increase in AMPK phosphorylation or glucose uptake after 16h EPS.
However, glucose uptake remained responsive to insulin in the CFS cells pointing to an exercise-related defect.
IL6 secretion in response to EPS was significantly reduced in CFS compared with control cultures at all time points measured.
Conclusion

EPS is an effective model for eliciting muscle contraction and the metabolic changes associated with exercise in cultured skeletal muscle cells.
We found four main differences in cultured skeletal muscle cells from subjects with CFS; increased myogenin expression in the basal state, impaired activation of AMPK, impaired stimulation of glucose uptake and diminished release of IL6.
The retention of these differences in cultured muscle cells from CFS subjects points to a genetic/epigenetic mechanism, and provides a system to identify novel therapeutic targets.


Full paper:

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0122982

 

[Dolphin]

Abnormalities of AMPK Activation and Glucose Uptake in Cultured Skeletal Muscle Cells from Individuals with Chronic Fatigue Syndrome


Julia Newton research involving muscle cell culture now published:
Abstract

Background

Post exertional muscle fatigue is a key feature in Chronic Fatigue Syndrome (CFS).
Abnormalities of skeletal muscle function have been identified in some but not all patients with CFS.
To try to limit potential confounders that might contribute to this clinical heterogeneity, we developed a novel in vitro system that allows comparison of AMP kinase (AMPK) activation and metabolic responses to exercise in cultured skeletal muscle cells from CFS patients and control subjects.
Methods

Skeletal muscle cell cultures were established from 10 subjects with CFS and 7 age-matched controls, subjected to electrical pulse stimulation (EPS) for up to 24h and examined for changes associated with exercise.
Results

In the basal state, CFS cultures showed increased myogenin expression but decreased IL6 secretion during differentiation compared with control cultures.
Control cultures subjected to 16h EPS showed a significant increase in both AMPK phosphorylation and glucose uptake compared with unstimulated cells.
In contrast, CFS cultures showed no increase in AMPK phosphorylation or glucose uptake after 16h EPS.
However, glucose uptake remained responsive to insulin in the CFS cells pointing to an exercise-related defect.
IL6 secretion in response to EPS was significantly reduced in CFS compared with control cultures at all time points measured.
Conclusion

EPS is an effective model for eliciting muscle contraction and the metabolic changes associated with exercise in cultured skeletal muscle cells.
We found four main differences in cultured skeletal muscle cells from subjects with CFS; increased myogenin expression in the basal state, impaired activation of AMPK, impaired stimulation of glucose uptake and diminished release of IL6.
The retention of these differences in cultured muscle cells from CFS subjects points to a genetic/epigenetic mechanism, and provides a system to identify novel therapeutic targets.


Full paper:

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0122982

I've started a thread on this paper here: http://forums.phoenixrising.me/inde...-cultured-skeletal-muscle-cells-in-cfs.36689/

 

[msf]

Thanks for explaining the theory, Dr. Shepherd, but the first question that occurs to me is what is causing the production of ROS in the first place?

Again, I'm not criticizing this research, as it seems promising in terms of developing our understanding of ME, I just don't think it is likely to lead us to the cause(s).

 

[charles shepherd]

Thanks for explaining the theory, Dr. Shepherd, but the first question that occurs to me is what is causing the production of ROS in the first place?

Again, I'm not criticizing this research, as it seems promising in terms of developing our understanding of ME, I just don't think it is likely to lead us to the cause(s).

I'm not going to attempt to give a detailed sound answer - because I don't have one - and I will discuss this with Professor McArdle

At a very simple level, if you view ME/CFS as a three stage illness - predisposing, precipitating and perpetuating factors - with some form of immune system stressor, viral infections in particular, being the commonest precipitating factor, sometimes in combination with undue physical or mental stress at the time, then you could say that this 'lights the blue touchpaper, and sets a trail of events in progress, involving various disease pathways, one of which is ROS production…

Apologies for a very long sentence!