Heresy / Conjecture on the nature of PEM PESE PENE

You did absolutely, positively the right thing.

I had picked the thread about criteria for ME/CFS hypotheses from May to read every post of, both for background and to get a sense of the style of this forum, before making the first post. And while I can handwave around the rest of ME, it's PEM I stumbled over this conjecture for back 6 months ago.

You were absolutely correct to level set. I was just trying to demonstrate I knew those things; sorry if it came off defensive or worse.

 

I concur this is medicine's belief.

I realize Oxygen molecules cannot be brought into a cell by an ATP-ADP pump, for obvious reasons

But the supply of oxygen is too critical to the function of the cell, and the cascade of consequences if there's not enough too severe, to be left to chance. I've seen enough bits and pieces in the science (such as the item around the efficiency of myoglobin removing oxygen from hemoglobin) (whose source I can't cite because I simply don't remember it, and yes I would have failed as an academic) to be certain there's a mechanism there -- but until real scientists look there and find definitively what's there, I'll treat it as a hole in the relevant science. Medicine has not in nearly a century been able to make progress on PEM; I will continue to assume that the barrier to that progress is one or more beliefs medicine has not backed by measurement and fact.

Hence building a conjecture around what I think is a hole in the science

Thank you! And I hope you're right and I'm wrong.

 

no no you didnt, not at all, it was my own self doubt.

 

Yes but you were talking about autoimmunity - a quite different mechanism from allergy.

Are there such tunnels? I have not heard of any, certainly not associated with myoglobin.

If the immune system 'destroys' structures there will be inflammation, visible on MRI and histology. If an antibody simply blocks a channel then it might just reduce muscle function but standard testing of muscle function in ME/CFS has been normal and PEM is something that happens hours after use.

If myoglobin is being used as a local oxygen store that allows rapid access the oxygen must be binding and unbiinding all the time - maybe hundreds of times a second. If another molecule acts as a competitive binder it will be able to bind whether or not oxygen is around.

I cannot see what maths done on a computer has to do with diffusion in biology? Myoglobin molecules will never get anywhere near haemoglobin molecules inside red cells so there has to be some diffusion across membranes and through plasma.

I am pretty sure it is known that oxygen crosses membranes by diffusion just as water does, without any active transportation system - just between the macromolecules. The diameter of an oxygen molecule is I think 5 Angstrom units or less. The lattice of proteins and lipids in a membrane is unlikely to mesh so tightly to exclude something that size. The macromolecules are constantly moving around over each other so there is no rigid exclusion of other molecules. A vast range of small drug molecules (and quite a bit bigger than oxygen) cross cell membranes rapidly without having any special transport systems.

Is there any evidence that globe's stick out like this? I have never heard it suggested. How would it help if the haemoglobin is inside the red cell membrane?

Actually your suggestions are pretty familiar from within medicine. Scientists working on ME/CFS are frequently dug in to ideas about autoimmunity and triggers and oxygen availability. My own view is that we need to think way outside those boxes.

 

I don't think it is anyone's 'belief'. I think it is something that has been demonstrated empirically many times.

And if the moving macromoleules in the membrane are not congruent down to below 5 Angstrom units and have plenty of non-polar areas what is to stop the oxygen going through? There would be nothing random about it since net flux would depend entirely on concentration gradient.

 

I think that's based on only some people's experiences with ME. There's another subset that doesn't experience a reduction in physical ability. My typical experience of PEM was knowing (proven by times I had to exert) that my legs were fully capable of a 40 km bike ride, but I just wanted to flop onto a pillow. I could probably have managed to pedal for hours with my upper body flopped onto a comfy pillow. I never experienced any sort of feeling that I lacked ATP production or ability to use it. My PEM symptoms seemed better explained by neurological dysfunction.

I still haven't seen any credible evidence of a reduction of ATP production or usage in PWME in general. Some studies show some reduction in metabolic function, but not at the level that would really explain the symptoms, and the reduction could be an effect of neurological or other mechanisms of dysfunction.

 

Sorry to hear about your daughter OP @FStevenChalmers hope she is improving.

re: "facts which make this wrong", agree putative mechanisms provide models which can be a worthwhile muse. Not qualified to comment on electronic analogies.

With this dandelion idea I find myself objecting to radical ideas about myoglobin which don't fit what I have read about myglobin structure or distribution. I am all for disrupting dogma but using scientific evidence. So below is the kind of evidence which could make me Mr Grinch, I am not dismissing the abstract principles behind the idea, just questioning this proposed mechanism and molecular candidate.

Myoglobin is allegedly kind of spherical and was the first molecule characterised using X-ray crystallography, no tail in any pictures I have seen. According to the wiki, the protein structure probably wraps around the porphryn and acts like a cage to prevent porphryn groups interacting and forming an inactive dimer. So they are a bit like air-flow practice golf balls.

https://en.wikipedia.org/wiki/Myoglobin#Synthetic_analogues

ref: Lippard SJ, Berg JM (1994). Principles of Bioinorganic Chemistry. Mill Valley, CA: University Science Books.


Myoglobin seems to function a bit like an emergent self assembling oxygen conduction and storage pipeline inside cells, expediting transfer down a gradient and maximising local concentrations and it does not seem to be exclusively located around the cell membrane. (following caps not mine sry)

"IMMUNO-HISTOCHEMICAL LOCALIZATION OF MYOGLOBIN IN HUMAN MUSCLE TISSUE AND EMBRYONAL AND ALVEOLAR RHABDOMYOSARCOMA"

https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1699-0463.1982.tb00078_90A.x

"Light and electron microscopic studies on localization of myoglobin in skeletal muscle cells in neuromuscular diseases."

https://onlinelibrary.wiley.com/doi/abs/10.1002/mus.880140409

If its in the I-band its not simply at the membrane. You would need to have it change conformation at the membrane or a separate gateway molecule at the membrane to make this idea work. Not saying that is impossible, we are nothing if not ignorant as to our own nature but all I have read, everyone seems happy with the idea of O2 diffusion kinetics providing oxygen to the cell cytoplasm and no discussions of trans-membrane oxygen transporters as O2 is considered non polar, which is why imho myoglobin is probably not the right molecular candidate for an immune activated obstruction to aerobic respiration.

However its true something funny is going on with respiration in ME. Yes there are reports of excess lactic acid production in ME CFS.

"Elevated blood lactate in resting conditions correlate with post-exertional malaise severity in patients with Myalgic encephalomyelitis/Chronic fatigue syndrome" https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6906377/
"Abnormal blood lactate accumulation during repeated exercise testing in myalgic encephalomyelitis/chronic fatigue syndrome"
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6546966/

Interestingly Prof Ron Davis nano needle tests discovered that plasma from ME CFS blood could convert normal control cells to ME cells and vice versa, ME cells could normalise in normal plasma. I seem to recall another similar experiment by someone but cannot remember the ref.

So yes something funny is going on involving some kind of signal or obstructive molecules in ME plasma but I think myoglobin is probably not where I would start.

My preferred over-arching theory is dysfunction of an immune state change which is an evolved mechanism to change how energy is used systemically thoughout the body in response to immune challenge.

I dont think an O2 channelopathy hypothesis is likely when we dont have a channel, nor would it account for the observed extensive changes in immune cell morphology e.g. some more from Ron Davis' team.

"Phenotypic characteristics of peripheral immune cells of Myalgic encephalomyelitis/chronic fatigue syndrome via transmission electron microscopy: A pilot study" 2022 Aug 9 : https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9362953/

Thats it I am done pushing my boulder uphill for today!

 

Yes, the immunohistochemistry confirms a diffuse cytosolic distribution without any obvious membrane staining - a long way away from any haemoglobin I am afraid.

 

It hasn't done a fat lot of looking, TBH!

There's not much research into the phenomenon itself. Much of the respectable work seems to have been done on demonstrating that it happens; that people's ability to exercise deteriorates. Even then it seems to be quite a mixed picture between individual subjects and controls.

I'm not sure a great deal has been done on the immune component of PEM, possibly because it's really hard. But any theorem has to account for it, as it's quite a significant part of the picture. I rarely get severe PEM now I'm retired, which means the runny nose, sore throat, swollen neck glands, headache, hot/cold/hot/cold etc is often the most bothersome bit.

 

My experience of hanging out in forums and reading papers relentlessly for the last 7 years or so is this:

Credible, plausible theories of mecfs, that fit the existing evidence and explain the symptoms, are as abundant as grains of sand.

The existing evidence is spotty, the symptoms are broad. It leaves a vast space in which theories can be developed.

I've seen amateurs and experts develop theories that make perfect sense and are very exciting. Calcium channels, purinergic signalling, IDO1, erythrocyte membranes, viral persistence, autoantibodies, mitochondrial fission, etc etc. Some are published, some are developed in less formal channels. All probably contain a little kernel of truth. But none yet seem to point to the most upstream problem.

We will know we have a good theory when a) it matches a clear signal in the data, and b) it leads to a treatment.

I don't want to discourage theory-making, it's vital. I do want to discourage anyone from falling too deeply in love with any single theory before data comes along to support it.

 

Well said.

I actually hope I'm wrong. If my conjecture is correct it will take medicine 50 years to accept. People need an objective test, and treatment, much sooner than that.

No matter how it sounds, I'm really here seeking facts which indicate my conjecture is wrong. Facts are really hard to come by in the ME space, given the noise from special interests.

Thank you! -steve

 

Thank you for the gift of an enormous amount of work chasing references to "facts which make [my conjecture] wrong". You've given me more to think about in one post here than I've seen over the last 6 months. Lots of homework to do. Thank you! -steve

 

Sorry my brain is not currently able to process this thread, but I do agree that there is a strong chance that to understand the aetiology of ME we will need a new perspective, that may not sit comfortably with current medical thinking.

So well done @FStevenChalmers for pursuing this model.

 

Thanks for your kind words. To criticise my own post though, I added strikethrough and rephrased one sentence to hold myself to a higher standard because I used the phrase "self assembly" a bit too loosely, as it is by convention associated with structures like tubulin and actin which do form strands by self assembly.

To the best of my knowledge this does not happen with myoglobin, I was merely trying to convey that myoglobin colocating in a particular region creates an oxygen store in that region due to the affinity between the iron and the oxygen which presumably reduces the partial pressure of O2 in that location allowing more to remain there until needed. In fact that was an unfortunate turn of phrase as myoglobin clumping would appear to be undesirable and not what it does in vivo.

It is a source of wonder to me that myoglobin appears to be part of how marine mammals can hold their breath for so long. Reports suggest marine mammal myoglobin has evolved to not stick together by becoming +vely charged and thus mutually repulsive, which is the opposite of self assembly in the sense of the way cytoskeletal molecules behave and is why myoglobin concentration can be so much higher in those species, enough to make their muscle tissues look black rather than red, holding far more oxygen than ours can.

The role of myoglobin in the evolution of mammalian diving capacity – The August Krogh principle applied in molecular and evolutionary physiology
https://www.sciencedirect.com/science/article/abs/pii/S1095643320301963

This gives a perspective on myoglobin as more a kind of battery than a kind of tube/conduit.

I think the immuno-histology evidence is worth discussing because there is no "rind" on available images of stained cells, i.e. you dont see the stain strongly, if at all, in the membrane. The descriptions match this and could mean either no myoglobin is present in the membrane or that the binding sites for the stain are obstructed in that location which is why I suggested, as a Hail Mary pass that a conformation change or close association with other molecules could in theory explain that but there is no other evidence to support that notion. It doesnt look like there is a conduit with an external face which could be removed.

Besides this there is the immunology of the dandelion idea, others may know more about this than me as I don't claim expertise in anything really and especially not in relation to the immune system as it is unbelievably complex but what I have read suggests nibbling antigens is not how immune cells work. None of the mechanisms I have read about suggest they can selectively edit flags at the cell surface, like a bunny grazing dandelions, they read them and either eat the whole cell or leave it alone. Please correct me if I am wrong.